* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
@ 2011-08-24 17:16 Guenter Roeck
2011-08-25 10:30 ` J, KEERTHY
0 siblings, 1 reply; 19+ messages in thread
From: Guenter Roeck @ 2011-08-24 17:16 UTC (permalink / raw)
To: Keerthy; +Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> On chip temperature sensor driver. The driver monitors the temperature of
> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> the temperature crosses user defined thresholds via kobject_uevent interface.
> The user is allowed to configure the temperature thresholds vis sysfs nodes
> exposed using hwmon interface.
>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> Cc: Jean Delvare <khali@linux-fr.org>
> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> Cc: lm-sensors@lm-sensors.org
Partial review only. Too many concerns, and after a while I tend to loose track.
> ---
> Documentation/hwmon/omap_temp_sensor | 27 +
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
> 4 files changed, 972 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/hwmon/omap_temp_sensor
> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>
> diff --git a/Documentation/hwmon/omap_temp_sensor b/Documentation/hwmon/omap_temp_sensor
> new file mode 100644
> index 0000000..e01a6d6
> --- /dev/null
> +++ b/Documentation/hwmon/omap_temp_sensor
> @@ -0,0 +1,27 @@
> +Kernel driver omap_temp_sensor
> +==============================
> +
> +Supported chips:
> + * Texas Instruments OMAP4460
> + Prefix: 'omap_temp_sensor'
> + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
> +
I am a bit lost here. What does the TMP102 have to do with the OMAP4460 ?
> +Author:
> + J Keerthy <j-keerthy@ti.com>
> +
> +Description
> +-----------
> +
> +The Texas Instruments OMAP4 family of chips have a bandgap temperature sensor.
> +The temperature sensor feature is used to convert the temperature of the device
> +into a decimal value coded on 10 bits. An internal ADC is used for conversion.
> +The recommended operating temperatures must be in the range -40 degree Celsius
> +to 123 degree celsius for standard conversion.
> +The thresholds are programmable and upon crossing the thresholds an interrupt
> +is generated. The OMAP temperature sensor has a programmable update rate in
> +milli seconds.
> +(Currently the driver programs a default of 2000 milli seconds).
> +
s/milli seconds/milliseconds/
> +The driver provides the common sysfs-interface for temperatures (see
> +Documentation/hwmon/sysfs-interface under Temperatures).
> +
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 5f888f7..9c9cd8b 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -323,6 +323,17 @@ config SENSORS_F71805F
> This driver can also be built as a module. If so, the module
> will be called f71805f.
>
> +config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
> + bool "OMAP on-die temperature sensor hwmon driver"
> + depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
> + help
> + If you say yes here you get support for hardware
> + monitoring features of the OMAP on die temperature
> + sensor.
> +
> + Continuous conversion programmable delay
> + mode is used for temperature conversion.
> +
> config SENSORS_F71882FG
> tristate "Fintek F71882FG and compatibles"
> help
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 28061cf..d0f89f5 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> +obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
> diff --git a/drivers/hwmon/omap_temp_sensor.c b/drivers/hwmon/omap_temp_sensor.c
> new file mode 100644
> index 0000000..66fb3a9
> --- /dev/null
> +++ b/drivers/hwmon/omap_temp_sensor.c
> @@ -0,0 +1,933 @@
> +/*
> + * OMAP4 Temperature sensor driver file
> + *
> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
> + * Author: J Keerthy <j-keerthy@ti.com>
> + * Author: Moiz Sonasath <m-sonasath@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <plat/omap_device.h>
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/jiffies.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/stddef.h>
> +#include <linux/sysfs.h>
> +#include <linux/err.h>
> +#include <linux/types.h>
> +#include <linux/mutex.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/delay.h>
> +#include <plat/temperature_sensor.h>
> +
> +#define TSHUT_HOT 920 /* 122 deg C */
> +#define TSHUT_COLD 866 /* 100 deg C */
> +#define T_HOT 800 /* 73 deg C */
> +#define T_COLD 795 /* 71 deg C */
> +#define OMAP_ADC_START_VALUE 530
> +#define OMAP_ADC_END_VALUE 923
> +#define MAX_FREQ 2000000
> +#define MIN_FREQ 1000000
> +
> +/*
> + * omap_temp_sensor structure
> + * @hwmon_dev - device pointer
> + * @clock - Clock pointer
> + * @registers - Pointer to structure with register offsets and bitfields
> + * @sensor_mutex - Mutex for sysfs, irq and PM
> + * @irq - MPU Irq number for thermal alert
> + * @phy_base - Physical base of the temp I/O
> + * @clk_rate - Holds current clock rate
> + * @temp_sensor_ctrl - temp sensor control register value
> + * @bg_ctrl - bandgap ctrl register value
> + * @bg_counter - bandgap counter value
> + * @bg_threshold - bandgap threshold register value
> + * @temp_sensor_tshut_threshold - bandgap tshut register value
> + * @is_efuse_valid - Flag to determine if efuse is valid or not
> + * @clk_on - Manages the current clock state
> + */
> +struct omap_temp_sensor {
> + struct device *hwmon_dev;
> + struct clk *clock;
> + struct omap_temp_sensor_registers *registers;
> + struct mutex sensor_mutex; /* Mutex for sysfs, irq and PM */
> + unsigned int irq;
> + void __iomem *phy_base;
> + u32 clk_rate;
> + u32 temp_sensor_ctrl;
> + u32 bg_ctrl;
> + u32 bg_counter;
> + u32 bg_threshold;
> + u32 temp_sensor_tshut_threshold;
> + bool is_efuse_valid;
> + bool clk_on;
> +};
> +
> +/*
> + * Temperature values in milli degree celsius
> + * ADC code values from 530 to 923
> + */
> +static int adc_to_temp[] = {
>
This array should have an explicit size.
>
> + -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200,
> + -37800, -37300, -36800, -36400, -36000, -35600, -35200, -34800,
> + -34300, -33800, -33400, -33000, -32600, -32200, -31800, -31300,
> + -30800, -30400, -30000, -29600, -29200, -28700, -28200, -27800,
> + -27400, -27000, -26600, -26200, -25700, -25200, -24800, -24400,
> + -24000, -23600, -23200, -22700, -22200, -21800, -21400, -21000,
> + -20600, -20200, -19700, -19200, -18800, -18400, -18000, -17600,
> + -17200, -16700, -16200, -15800, -15400, -15000, -14600, -14200,
> + -13700, -13200, -12800, -12400, -12000, -11600, -11200, -10700,
> + -10200, -9800, -9400, -9000, -8600, -8200, -7700, -7200, -6800,
> + -6400, -6000, -5600, -5200, -4800, -4300, -3800, -3400, -3000,
> + -2600, -2200, -1800, -1300, -800, -400, 0, 400, 800, 1200, 1600,
> + 2100, 2600, 3000, 3400, 3800, 4200, 4600, 5100, 5600, 6000, 6400,
> + 6800, 7200, 7600, 8000, 8500, 9000, 9400, 9800, 10200, 10600, 11000,
> + 11400, 11900, 12400, 12800, 13200, 13600, 14000, 14400, 14800,
> + 15300, 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18700,
> + 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22100, 22600,
> + 23000, 23400, 23800, 24200, 24600, 25000, 25400, 25900, 26400,
> + 26800, 27200, 27600, 28000, 28400, 28800, 29300, 29800, 30200,
> + 30600, 31000, 31400, 31800, 32200, 32600, 33100, 33600, 34000,
> + 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37300, 37800,
> + 38200, 38600, 39000, 39400, 39800, 40200, 40600, 41100, 41600,
> + 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45300,
> + 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 49000,
> + 49500, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800,
> + 53200, 53700, 54200, 54600, 55000, 55400, 55800, 56200, 56600,
> + 57000, 57400, 57800, 58200, 58700, 59200, 59600, 60000, 60400,
> + 60800, 61200, 61600, 62000, 62400, 62800, 63300, 63800, 64200,
> + 64600, 65000, 65400, 65800, 66200, 66600, 67000, 67400, 67800,
> + 68200, 68700, 69200, 69600, 70000, 70400, 70800, 71200, 71600,
> + 72000, 72400, 72800, 73200, 73600, 74100, 74600, 75000, 75400,
> + 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600, 79000,
> + 79400, 79800, 80300, 80800, 81200, 81600, 82000, 82400, 82800,
> + 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400,
> + 86800, 87300, 87800, 88200, 88600, 89000, 89400, 89800, 90200,
> + 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 93800,
> + 94200, 94600, 95000, 95500, 96000, 96400, 96800, 97200, 97600,
> + 98000, 98400, 98800, 99200, 99600, 100000, 100400, 100800, 101200,
> + 101600, 102000, 102400, 102800, 103200, 103600, 104000, 104400,
> + 104800, 105200, 105600, 106100, 106600, 107000, 107400, 107800,
> + 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
> + 111400, 111800, 112200, 112600, 113000, 113400, 113800, 114200,
> + 114600, 115000, 115400, 115800, 116200, 116600, 117000, 117400,
> + 117800, 118200, 118600, 119000, 119400, 119800, 120200, 120600,
> + 121000, 121400, 121800, 122200, 122600, 123000
> +};
> +
> +static unsigned long omap_temp_sensor_readl(struct omap_temp_sensor
> + *temp_sensor, u32 reg)
> +{
> + return __raw_readl(temp_sensor->phy_base + reg);
> +}
> +
> +static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
> + u32 val, u32 reg)
> +{
> + __raw_writel(val, (temp_sensor->phy_base + reg));
Unnecessary ( )
> +}
> +
> +static int adc_to_temp_conversion(int adc_val)
> +{
> + return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
> +}
> +
> +static int temp_to_adc_conversion(long temp)
> +{
> + int high, low, mid;
> +
> + if (temp < adc_to_temp[0] ||
> + temp > adc_to_temp[OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE])
> + return -EINVAL;
> +
> + high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
> + low = 0;
> + mid = (high + low) / 2;
> +
> + while (low < high) {
> + if (temp < adc_to_temp[mid])
> + high = mid - 1;
> + else
> + low = mid + 1;
> + mid = (low + high) / 2;
> + }
> +
> + return OMAP_ADC_START_VALUE + low;
> +}
> +
> +static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
> + *temp_sensor)
> +{
> + u32 temp;
> +
> + /* Configure the TALERT thresholds */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp |= (T_HOT << __ffs(temp_sensor->registers->threshold_thot_mask)) |
> + (T_COLD << __ffs(temp_sensor->registers->threshold_tcold_mask));
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Configure the TSHUT thresholds */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->thsut_threshold);
> + temp |= (TSHUT_HOT << __ffs(temp_sensor->registers->tshut_hot_mask))
> + | (TSHUT_COLD << __ffs(temp_sensor->registers->tshut_hot_mask));
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static void omap_configure_temp_sensor_counter(struct omap_temp_sensor
> + *temp_sensor, u32 counter)
> +{
> + u32 val;
> +
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + val &= ~temp_sensor->registers->counter_mask;
> + val |= counter << __ffs(temp_sensor->registers->counter_mask);
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_counter);
> +}
> +
> +static void omap_enable_continuous_mode(struct omap_temp_sensor *temp_sensor,
> + bool enable)
The enable parameter is always 1 when called, and thus unnecessary.
> +{
> + u32 val;
> +
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mode_ctrl);
> +
> + if (enable)
> + val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
> + else
> + val &= ~temp_sensor->registers->mode_ctrl_mask;
> +
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_mode_ctrl);
> +}
> +
> +/* Sysfs hook functions */
> +
> +static ssize_t show_temp_max(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + int temp;
> +
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
> +
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid value\n");
> + return -EDOM;
Please don't use EDOM, and drop the error message.
> + }
> +
> + temp = adc_to_temp_conversion(temp);
> +
> + return snprintf(buf, 16, "%d\n", temp);
> +}
> +
> +static ssize_t set_temp_max(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + long val;
> + u32 reg_val, t_cold, t_hot, temp;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
This will try to release the not-acquired lock.
> + }
> +
> + t_hot = temp_to_adc_conversion(val);
Bad error return check. Negative on error. Should be
if (t_hot < 0)
return t_hot;
> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
Unnecessary (( ))
> + count = -EINVAL;
> + goto out;
This will try to release the not-acquired lock.
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + /* obtain the T cold value */
> + t_cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> +
> + if (t_hot < t_cold) {
> + count = -EINVAL;
> + goto out;
Context specific limitations like this one are not a good idea, since it assumes an order of changing max
and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
change order order well defined or even possible. Applications should not have to bother about this.
> + }
> +
> + /* write the new t_hot value */
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
> + reg_val |= (t_hot <<
> + __ffs(temp_sensor->registers->threshold_thot_mask));
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Read the current temperature */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /*
> + * If user sets the HIGH threshold(t_hot) greater than the current
> + * temperature(temp) unmask the HOT interrupts
> + */
> + if (t_hot > temp) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * If current temperature is in-between the hot and cold thresholds,
> + * Enable both masks.
> + */
> + if (temp > t_cold && temp < t_hot) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + OMAP4460_BGAP_CTRL_OFFSET);
Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
> + }
> + /*
> + * else no need to do anything since HW will immediately compare
> + * the new threshold and generate interrupt accordingly
> + */
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return count;
> +}
> +
> +static ssize_t show_temp_max_hyst(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 temp;
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
This lock would only make sense if threshold_tcold_mask can change, and if that change
would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
Besides, the code in show_temp_max() is almost the same and does not use the lock.
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid value\n");
> + return -EDOM;
"Math argument out of domain of func" does not make sense.
Unless you don't know anything better, use EIO (I/O Error). Not very specific,
but at least not misleading.
Besides, the log message is unnecessary. The user is informed with -EIO, and the admin
won't be able to do anything useful with "invalid value".
> + }
> +
> + temp = adc_to_temp_conversion(temp);
> +
> + return snprintf(buf, 16, "%d\n", temp);
> +}
> +
> +static ssize_t set_temp_max_hyst(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 reg_val, t_hot, t_cold, temp;
> + long val;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
This will try to release the not acquired lock.
> + }
> +
> + t_cold = temp_to_adc_conversion(val);
Bad error return check; same as above.
> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + /* obtain the T HOT value */
> + t_hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
> + __ffs(temp_sensor->registers->threshold_thot_mask);
> +
> + if (t_cold > t_hot) {
Same concern as above. Change order is left to application which should not be bothered.
> + count = -EINVAL;
> + goto out;
> + }
> +
> + /* write the new t_cold value */
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
> + reg_val |= t_cold <<
> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Read the current temperature */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /*
> + * If user sets the LOW threshold(t_cold) lower than the current
> + * temperature(temp) unmask the COLD interrupts
> + */
> + if (t_cold < temp) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * If current temperature is in-between the hot and cold thresholds,
> + * Enable both masks.
> + */
> + if (temp < t_hot && temp > t_cold) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * else no need to do anything since HW will immediately compare
> + * the new threshold and generate interrupt accordingly
> + */
Would be nice if you could unify the interrupt enable code in a single function.
> +
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return count;
> +}
> +
> +static ssize_t show_update_rate(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 temp = 0, ret = 0;
> +
No need to initialize temp.
ret is u32, which doesn't seem to be a good type to use for negative values.
> +
> + if (!temp_sensor->clk_rate) {
> + dev_err(dev, "clk_rate is NULL\n");
> + ret = -EDOM;
Same comment as above (this is not a math error). And you don't have to check clk_rate anyway,
since it is set in probe, and probe bails out if it is not set.
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
As with other show locks, this one would only make sense if counter_mask can change during runtime,
and if that change would be protected by the mutex. This is not the case, thus the lock is unnecessary.
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + temp = (temp & temp_sensor->registers->counter_mask) >>
> + __ffs(temp_sensor->registers->counter_mask);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> + temp = temp * 1000 / temp_sensor->clk_rate;
> +
> +out:
> + if (!ret)
> + return sprintf(buf, "%d\n", temp);
> +
> + return ret;
> +}
> +
> +static ssize_t set_update_rate(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 reg_val;
> + long val;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + val *= temp_sensor->clk_rate / 1000;
> + mutex_lock(&temp_sensor->sensor_mutex);
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> +
> + reg_val &= ~temp_sensor->registers->counter_mask;
> + reg_val |= val;
Sure you want to accept any value (including negative ones) here ?
val is not shifted, and not masked against counter_mask, meaning it can write
all bits of the register. That doesn't sound right.
It would make sense to call omap_configure_temp_sensor_counter() instead of duplicating
the set functionality.
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_counter);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +out:
> + return count;
> +}
> +
> +static int omap_temp_sensor_read_temp(struct device *dev,
> + struct device_attribute *devattr,
> + char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + int temp, ret = 0;
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
Unless bgap_dtemp_mask can change during runtime, and that change is protected by the mutex,
this lock is unnecessary.
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /* look up for temperature in the table and return the temperature */
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid adc code reported %d", temp);
> + ret = -EDOM;
Another wrong use of EDOM, and another value-free error message.
> + goto out;
> + }
> +
> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
> +
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> + if (!ret)
> + return sprintf(buf, "%d\n", temp);
> +
> + return ret;
> +}
> +
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, omap_temp_sensor_read_temp,
> + NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
> + set_temp_max, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_max_hyst,
> + set_temp_max_hyst, 0);
> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO, show_update_rate,
> + set_update_rate, 0);
> +
ABI is update_interval. Please use it.
> +static struct attribute *omap_temp_sensor_attributes[] = {
> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> + &sensor_dev_attr_temp1_max.dev_attr.attr,
> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
> + &sensor_dev_attr_update_rate.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group omap_temp_sensor_group = {
> + .attrs = omap_temp_sensor_attributes,
> +};
> +
> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor *temp_sensor)
> +{
> + u32 ret = 0;
> +
> + if (temp_sensor->clk_on) {
> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
> + goto out;
> + }
> +
> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
> + if (ret < 0) {
> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp_sensor->clk_on = 1;
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
Completely unnecessary lock.
> +out:
> + return ret;
> +}
> +
> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
Return code is not used anywhere, why bother providing one ?
> +{
> + u32 ret = 0;
> +
> + if (!temp_sensor->clk_on) {
> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
> + goto out;
... and since you ignore the error anyway, why log it ?
> + }
> +
> + /* Gate the clock */
> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
> + if (ret < 0) {
> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp_sensor->clk_on = 0;
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
Completely unnecessary lock.
> +out:
> + return ret;
> +}
> +
> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
> +{
> + struct omap_temp_sensor *temp_sensor;
> + int t_hot, t_cold, temp;
> +
> + temp_sensor = data;
> + mutex_lock(&temp_sensor->sensor_mutex);
> +
> + /* Read the status of t_hot */
> + t_hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_status)
> + & temp_sensor->registers->status_hot_mask;
> +
> + /* Read the status of t_cold */
> + t_cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_status)
> + & temp_sensor->registers->status_cold_mask;
> +
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + /*
> + * One TALERT interrupt: Two sources
> + * If the interrupt is due to t_hot then mask t_hot and
> + * and unmask t_cold else mask t_cold and unmask t_hot
> + */
> + if (t_hot) {
> + temp &= ~temp_sensor->registers->mask_hot_mask;
> + temp |= temp_sensor->registers->mask_cold_mask;
> + } else if (t_cold) {
> + temp &= ~temp_sensor->registers->mask_cold_mask;
> + temp |= temp_sensor->registers->mask_hot_mask;
> + }
> +
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->bgap_mask_ctrl);
> +
> + /* kobject_uvent to user space telling thermal threshold crossed */
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
> +
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
> +{
> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
> + struct omap_temp_sensor *temp_sensor;
> + struct resource *mem;
> + int ret = 0;
> + int val, clk_rate;
> + u32 max_freq, min_freq;
> +
> + if (!pdata) {
> + dev_err(&pdev->dev, "platform data missing\n");
> + return -EINVAL;
> + }
> +
> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
> + if (!temp_sensor)
> + return -ENOMEM;
> +
You have error messages all over the place, Why not here ?
> + mutex_init(&temp_sensor->sensor_mutex);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&pdev->dev, "no mem resource\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
If you try to get the resource before allocating the memory, you don't have to release
the memory if the platform resource is missing.
> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> + if (temp_sensor->irq < 0) {
> + dev_err(&pdev->dev, "get_irq_byname failed\n");
> + ret = temp_sensor->irq;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
> + temp_sensor->clock = NULL;
> + temp_sensor->registers = pdata->registers;
> + temp_sensor->hwmon_dev = &pdev->dev;
> +
> + if (pdata->max_freq && pdata->min_freq) {
> + max_freq = pdata->max_freq;
> + min_freq = pdata->min_freq;
> + } else {
> + max_freq = MAX_FREQ;
> + min_freq = MIN_FREQ;
> + }
> +
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_irq_safe(&pdev->dev);
> +
> + /*
> + * check if the efuse has a non-zero value if not
> + * it is an untrimmed sample and the temperatures
> + * may not be accurate
> + */
> +
> + if (omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_efuse)) {
> + temp_sensor->is_efuse_valid = 1;
is_efuse_valid is not used anywhere. Might as well drop it.
> + dev_dbg(temp_sensor->hwmon_dev,
> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
dev_info might be better here.
> + }
> +
> + dev_set_drvdata(&pdev->dev, temp_sensor);
> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
> + if (IS_ERR(temp_sensor->clock)) {
> + ret = PTR_ERR(temp_sensor->clock);
> + dev_err(temp_sensor->hwmon_dev,
> + "unable to get fclk: %d\n", ret);
> + goto plat_res_err;
> + }
> +
> + ret = omap_temp_sensor_clk_enable(temp_sensor);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
omap_temp_sensor_clk_enable() already generates error messages.
> + goto clken_err;
> + }
> +
> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
> + dev_err(&pdev->dev, "Error round rate\n");
> + ret = -EDOM;
EDOM is wrong. Please use ENODEV.
The error log doesn't really provide anything useful to the administrator.
Either add parameters, or drop it.
> + goto clken_err;
> + }
> +
> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot set clock rate\n");
> + goto clken_err;
> + }
> +
> + temp_sensor->clk_rate = clk_rate;
> + omap_enable_continuous_mode(temp_sensor, 1);
> + omap_configure_temp_sensor_thresholds(temp_sensor);
> + /* 1 ms */
> + omap_configure_temp_sensor_counter(temp_sensor, 1);
If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
1ms would be temp_sensor->clk_rate / 1000.
> +
> + /* Wait till the first conversion is done wait for at least 1ms */
> + usleep_range(1000, 2000);
> +
> + /* Read the temperature once due to hw issue*/
> + omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> +
> + /* Set 2 seconds time as default counter */
> + omap_configure_temp_sensor_counter(temp_sensor,
> + temp_sensor->clk_rate * 2);
> +
> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> + if (IS_ERR(temp_sensor->hwmon_dev)) {
> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
> + ret = PTR_ERR(temp_sensor->hwmon_dev);
> + goto hwmon_reg_err;
> + }
> +
> + ret = sysfs_create_group(&pdev->dev.kobj,
> + &omap_temp_sensor_group);
one line is sufficient here.
> + if (ret) {
> + dev_err(&pdev->dev, "could not create sysfs files\n");
> + goto sysfs_create_err;
> + }
> +
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
> +
No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
> + ret = request_threaded_irq(temp_sensor->irq, NULL,
> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> + "temp_sensor", temp_sensor);
> + if (ret) {
> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
> + goto req_irq_err;
> + }
> +
> + /* unmask the T_COLD and unmask T_HOT at init */
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + val |= temp_sensor->registers->mask_cold_mask
> + | temp_sensor->registers->mask_hot_mask;
> +
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_mask_ctrl);
> +
This is racy. From Documentation/hwmon/submitting-patches:
* Make sure there are no race conditions in the probe function. Specifically,
completely initialize your chip first, then create sysfs entries and register
with the hwmon subsystem.
> + return 0;
> +
> +req_irq_err:
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
Same as before; why is this needed here but not in any other hwmon driver ?
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> +sysfs_create_err:
> + hwmon_device_unregister(&pdev->dev);
> +hwmon_reg_err:
> + omap_temp_sensor_clk_disable(temp_sensor);
> +clken_err:
> + clk_put(temp_sensor->clock);
> +plat_res_err:
> + dev_set_drvdata(&pdev->dev, NULL);
> + mutex_destroy(&temp_sensor->sensor_mutex);
> + kfree(temp_sensor);
> + return ret;
> +}
> +
> +static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
> +{
> + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
> +
> + hwmon_device_unregister(&pdev->dev);
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
... and again.
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> + omap_temp_sensor_clk_disable(temp_sensor);
> + free_irq(temp_sensor->irq, temp_sensor);
> + clk_put(temp_sensor->clock);
> + dev_set_drvdata(&pdev->dev, NULL);
> + mutex_destroy(&temp_sensor->sensor_mutex);
> + kfree(temp_sensor);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static void omap_temp_sensor_save_ctxt(struct omap_temp_sensor *temp_sensor)
> +{
> + temp_sensor->temp_sensor_ctrl = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp_sensor->bg_ctrl = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + temp_sensor->bg_counter = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + temp_sensor->bg_threshold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp_sensor->temp_sensor_tshut_threshold =
> + omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static void omap_temp_sensor_restore_ctxt(struct omap_temp_sensor *temp_sensor)
> +{
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->temp_sensor_ctrl,
> + temp_sensor->registers->temp_sensor_ctrl);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_ctrl,
> + temp_sensor->registers->bgap_mask_ctrl);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_counter,
> + temp_sensor->registers->bgap_counter);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_threshold,
> + temp_sensor->registers->bgap_threshold);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->temp_sensor_tshut_threshold,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static int omap_temp_sensor_suspend(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_save_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_resume(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_restore_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_runtime_suspend(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_save_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_runtime_resume(struct device *dev)
> +{
> + static int context_loss_count;
> + int temp;
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + temp = omap_device_get_context_loss_count(to_platform_device(dev));
> +
> + if (temp != context_loss_count && context_loss_count != 0)
> + omap_temp_sensor_restore_ctxt(temp_sensor);
> +
> + context_loss_count = temp;
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_idle(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(omap_temp_sensor_suspend,
> + omap_temp_sensor_resume)
> + SET_RUNTIME_PM_OPS(omap_temp_sensor_runtime_suspend,
> + omap_temp_sensor_runtime_resume, omap_temp_sensor_idle)
> +};
> +
> +#define DEV_PM_OPS (&omap_temp_sensor_dev_pm_ops)
> +#else
> +#define DEV_PM_OPS NULL
> +#endif
> +
> +static struct platform_driver omap_temp_sensor_driver = {
> + .probe = omap_temp_sensor_probe,
> + .remove = omap_temp_sensor_remove,
> + .driver = {
> + .name = "omap_temp_sensor",
> + .pm = DEV_PM_OPS,
> + },
> +};
> +
> +int __init omap_temp_sensor_init(void)
> +{
> + return platform_driver_register(&omap_temp_sensor_driver);
> +}
> +module_init(omap_temp_sensor_init);
> +
> +static void __exit omap_temp_sensor_exit(void)
> +{
> + platform_driver_unregister(&omap_temp_sensor_driver);
> +}
> +module_exit(omap_temp_sensor_exit);
> +
> +MODULE_DESCRIPTION("OMAP446X temperature sensor Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> +MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
> --
> 1.7.0.4
>
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 17:16 [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver Guenter Roeck
@ 2011-08-25 10:30 ` J, KEERTHY
2011-08-25 14:06 ` Guenter Roeck
0 siblings, 1 reply; 19+ messages in thread
From: J, KEERTHY @ 2011-08-25 10:30 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> On chip temperature sensor driver. The driver monitors the temperature of
>> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> the temperature crosses user defined thresholds via kobject_uevent interface.
>> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> exposed using hwmon interface.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> Cc: Jean Delvare <khali@linux-fr.org>
>> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> Cc: lm-sensors@lm-sensors.org
>
> Partial review only. Too many concerns, and after a while I tend to loose track.
>
>> ---
>> Documentation/hwmon/omap_temp_sensor | 27 +
>> drivers/hwmon/Kconfig | 11 +
>> drivers/hwmon/Makefile | 1 +
>> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
>> 4 files changed, 972 insertions(+), 0 deletions(-)
>> create mode 100644 Documentation/hwmon/omap_temp_sensor
>> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>>
>> diff --git a/Documentation/hwmon/omap_temp_sensor b/Documentation/hwmon/omap_temp_sensor
>> new file mode 100644
>> index 0000000..e01a6d6
>> --- /dev/null
>> +++ b/Documentation/hwmon/omap_temp_sensor
>> @@ -0,0 +1,27 @@
>> +Kernel driver omap_temp_sensor
>> +==============================
>> +
>> +Supported chips:
>> + * Texas Instruments OMAP4460
>> + Prefix: 'omap_temp_sensor'
>> + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
>> +
>
> I am a bit lost here. What does the TMP102 have to do with the OMAP4460 ?
My mistake. I will point to the correct data sheet.
>
>> +Author:
>> + J Keerthy <j-keerthy@ti.com>
>> +
>> +Description
>> +-----------
>> +
>> +The Texas Instruments OMAP4 family of chips have a bandgap temperature sensor.
>> +The temperature sensor feature is used to convert the temperature of the device
>> +into a decimal value coded on 10 bits. An internal ADC is used for conversion.
>> +The recommended operating temperatures must be in the range -40 degree Celsius
>> +to 123 degree celsius for standard conversion.
>> +The thresholds are programmable and upon crossing the thresholds an interrupt
>> +is generated. The OMAP temperature sensor has a programmable update rate in
>> +milli seconds.
>> +(Currently the driver programs a default of 2000 milli seconds).
>> +
>
> s/milli seconds/milliseconds/
Ok
>
>> +The driver provides the common sysfs-interface for temperatures (see
>> +Documentation/hwmon/sysfs-interface under Temperatures).
>> +
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 5f888f7..9c9cd8b 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -323,6 +323,17 @@ config SENSORS_F71805F
>> This driver can also be built as a module. If so, the module
>> will be called f71805f.
>>
>> +config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
>> + bool "OMAP on-die temperature sensor hwmon driver"
>> + depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
>> + help
>> + If you say yes here you get support for hardware
>> + monitoring features of the OMAP on die temperature
>> + sensor.
>> +
>> + Continuous conversion programmable delay
>> + mode is used for temperature conversion.
>> +
>> config SENSORS_F71882FG
>> tristate "Fintek F71882FG and compatibles"
>> help
>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>> index 28061cf..d0f89f5 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
>> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
>> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
>> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
>> +obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
>> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
>> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
>> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
>> diff --git a/drivers/hwmon/omap_temp_sensor.c b/drivers/hwmon/omap_temp_sensor.c
>> new file mode 100644
>> index 0000000..66fb3a9
>> --- /dev/null
>> +++ b/drivers/hwmon/omap_temp_sensor.c
>> @@ -0,0 +1,933 @@
>> +/*
>> + * OMAP4 Temperature sensor driver file
>> + *
>> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
>> + * Author: J Keerthy <j-keerthy@ti.com>
>> + * Author: Moiz Sonasath <m-sonasath@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful, but
>> + * WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
>> + * 02110-1301 USA
>> + *
>> + */
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/clk.h>
>> +#include <linux/io.h>
>> +#include <linux/slab.h>
>> +#include <linux/init.h>
>> +#include <plat/omap_device.h>
>> +#include <linux/kernel.h>
>> +#include <linux/device.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/stddef.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/err.h>
>> +#include <linux/types.h>
>> +#include <linux/mutex.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/delay.h>
>> +#include <plat/temperature_sensor.h>
>> +
>> +#define TSHUT_HOT 920 /* 122 deg C */
>> +#define TSHUT_COLD 866 /* 100 deg C */
>> +#define T_HOT 800 /* 73 deg C */
>> +#define T_COLD 795 /* 71 deg C */
>> +#define OMAP_ADC_START_VALUE 530
>> +#define OMAP_ADC_END_VALUE 923
>> +#define MAX_FREQ 2000000
>> +#define MIN_FREQ 1000000
>> +
>> +/*
>> + * omap_temp_sensor structure
>> + * @hwmon_dev - device pointer
>> + * @clock - Clock pointer
>> + * @registers - Pointer to structure with register offsets and bitfields
>> + * @sensor_mutex - Mutex for sysfs, irq and PM
>> + * @irq - MPU Irq number for thermal alert
>> + * @phy_base - Physical base of the temp I/O
>> + * @clk_rate - Holds current clock rate
>> + * @temp_sensor_ctrl - temp sensor control register value
>> + * @bg_ctrl - bandgap ctrl register value
>> + * @bg_counter - bandgap counter value
>> + * @bg_threshold - bandgap threshold register value
>> + * @temp_sensor_tshut_threshold - bandgap tshut register value
>> + * @is_efuse_valid - Flag to determine if efuse is valid or not
>> + * @clk_on - Manages the current clock state
>> + */
>> +struct omap_temp_sensor {
>> + struct device *hwmon_dev;
>> + struct clk *clock;
>> + struct omap_temp_sensor_registers *registers;
>> + struct mutex sensor_mutex; /* Mutex for sysfs, irq and PM */
>> + unsigned int irq;
>> + void __iomem *phy_base;
>> + u32 clk_rate;
>> + u32 temp_sensor_ctrl;
>> + u32 bg_ctrl;
>> + u32 bg_counter;
>> + u32 bg_threshold;
>> + u32 temp_sensor_tshut_threshold;
>> + bool is_efuse_valid;
>> + bool clk_on;
>> +};
>> +
>> +/*
>> + * Temperature values in milli degree celsius
>> + * ADC code values from 530 to 923
>> + */
>> +static int adc_to_temp[] = {
>>
> This array should have an explicit size.
Ok
>
>>
>> + -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200,
>> + -37800, -37300, -36800, -36400, -36000, -35600, -35200, -34800,
>> + -34300, -33800, -33400, -33000, -32600, -32200, -31800, -31300,
>> + -30800, -30400, -30000, -29600, -29200, -28700, -28200, -27800,
>> + -27400, -27000, -26600, -26200, -25700, -25200, -24800, -24400,
>> + -24000, -23600, -23200, -22700, -22200, -21800, -21400, -21000,
>> + -20600, -20200, -19700, -19200, -18800, -18400, -18000, -17600,
>> + -17200, -16700, -16200, -15800, -15400, -15000, -14600, -14200,
>> + -13700, -13200, -12800, -12400, -12000, -11600, -11200, -10700,
>> + -10200, -9800, -9400, -9000, -8600, -8200, -7700, -7200, -6800,
>> + -6400, -6000, -5600, -5200, -4800, -4300, -3800, -3400, -3000,
>> + -2600, -2200, -1800, -1300, -800, -400, 0, 400, 800, 1200, 1600,
>> + 2100, 2600, 3000, 3400, 3800, 4200, 4600, 5100, 5600, 6000, 6400,
>> + 6800, 7200, 7600, 8000, 8500, 9000, 9400, 9800, 10200, 10600, 11000,
>> + 11400, 11900, 12400, 12800, 13200, 13600, 14000, 14400, 14800,
>> + 15300, 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18700,
>> + 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22100, 22600,
>> + 23000, 23400, 23800, 24200, 24600, 25000, 25400, 25900, 26400,
>> + 26800, 27200, 27600, 28000, 28400, 28800, 29300, 29800, 30200,
>> + 30600, 31000, 31400, 31800, 32200, 32600, 33100, 33600, 34000,
>> + 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37300, 37800,
>> + 38200, 38600, 39000, 39400, 39800, 40200, 40600, 41100, 41600,
>> + 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45300,
>> + 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 49000,
>> + 49500, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800,
>> + 53200, 53700, 54200, 54600, 55000, 55400, 55800, 56200, 56600,
>> + 57000, 57400, 57800, 58200, 58700, 59200, 59600, 60000, 60400,
>> + 60800, 61200, 61600, 62000, 62400, 62800, 63300, 63800, 64200,
>> + 64600, 65000, 65400, 65800, 66200, 66600, 67000, 67400, 67800,
>> + 68200, 68700, 69200, 69600, 70000, 70400, 70800, 71200, 71600,
>> + 72000, 72400, 72800, 73200, 73600, 74100, 74600, 75000, 75400,
>> + 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600, 79000,
>> + 79400, 79800, 80300, 80800, 81200, 81600, 82000, 82400, 82800,
>> + 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400,
>> + 86800, 87300, 87800, 88200, 88600, 89000, 89400, 89800, 90200,
>> + 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 93800,
>> + 94200, 94600, 95000, 95500, 96000, 96400, 96800, 97200, 97600,
>> + 98000, 98400, 98800, 99200, 99600, 100000, 100400, 100800, 101200,
>> + 101600, 102000, 102400, 102800, 103200, 103600, 104000, 104400,
>> + 104800, 105200, 105600, 106100, 106600, 107000, 107400, 107800,
>> + 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
>> + 111400, 111800, 112200, 112600, 113000, 113400, 113800, 114200,
>> + 114600, 115000, 115400, 115800, 116200, 116600, 117000, 117400,
>> + 117800, 118200, 118600, 119000, 119400, 119800, 120200, 120600,
>> + 121000, 121400, 121800, 122200, 122600, 123000
>> +};
>> +
>> +static unsigned long omap_temp_sensor_readl(struct omap_temp_sensor
>> + *temp_sensor, u32 reg)
>> +{
>> + return __raw_readl(temp_sensor->phy_base + reg);
>> +}
>> +
>> +static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
>> + u32 val, u32 reg)
>> +{
>> + __raw_writel(val, (temp_sensor->phy_base + reg));
>
> Unnecessary ( )
I will remove them.
>
>> +}
>> +
>> +static int adc_to_temp_conversion(int adc_val)
>> +{
>> + return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
>> +}
>> +
>> +static int temp_to_adc_conversion(long temp)
>> +{
>> + int high, low, mid;
>> +
>> + if (temp < adc_to_temp[0] ||
>> + temp > adc_to_temp[OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE])
>> + return -EINVAL;
>> +
>> + high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
>> + low = 0;
>> + mid = (high + low) / 2;
>> +
>> + while (low < high) {
>> + if (temp < adc_to_temp[mid])
>> + high = mid - 1;
>> + else
>> + low = mid + 1;
>> + mid = (low + high) / 2;
>> + }
>> +
>> + return OMAP_ADC_START_VALUE + low;
>> +}
>> +
>> +static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
>> + *temp_sensor)
>> +{
>> + u32 temp;
>> +
>> + /* Configure the TALERT thresholds */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp |= (T_HOT << __ffs(temp_sensor->registers->threshold_thot_mask)) |
>> + (T_COLD << __ffs(temp_sensor->registers->threshold_tcold_mask));
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Configure the TSHUT thresholds */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->thsut_threshold);
>> + temp |= (TSHUT_HOT << __ffs(temp_sensor->registers->tshut_hot_mask))
>> + | (TSHUT_COLD << __ffs(temp_sensor->registers->tshut_hot_mask));
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static void omap_configure_temp_sensor_counter(struct omap_temp_sensor
>> + *temp_sensor, u32 counter)
>> +{
>> + u32 val;
>> +
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + val &= ~temp_sensor->registers->counter_mask;
>> + val |= counter << __ffs(temp_sensor->registers->counter_mask);
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_counter);
>> +}
>> +
>> +static void omap_enable_continuous_mode(struct omap_temp_sensor *temp_sensor,
>> + bool enable)
>
> The enable parameter is always 1 when called, and thus unnecessary.
Ok.
>
>> +{
>> + u32 val;
>> +
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mode_ctrl);
>> +
>> + if (enable)
>> + val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
>> + else
>> + val &= ~temp_sensor->registers->mode_ctrl_mask;
>> +
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_mode_ctrl);
>> +}
>> +
>> +/* Sysfs hook functions */
>> +
>> +static ssize_t show_temp_max(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + int temp;
>> +
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
>> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
>> +
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid value\n");
>> + return -EDOM;
>
> Please don't use EDOM, and drop the error message.
The temperature is out of range. Should i use EIO?
>
>> + }
>> +
>> + temp = adc_to_temp_conversion(temp);
>> +
>> + return snprintf(buf, 16, "%d\n", temp);
>> +}
>> +
>> +static ssize_t set_temp_max(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + long val;
>> + u32 reg_val, t_cold, t_hot, temp;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>
> This will try to release the not-acquired lock.
I will correct this.
>
>> + }
>> +
>> + t_hot = temp_to_adc_conversion(val);
>
> Bad error return check. Negative on error. Should be
> if (t_hot < 0)
> return t_hot;
Ok.
>
>> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
>
> Unnecessary (( ))
This check is unnecessary with the negative check. I will remove.
>
>> + count = -EINVAL;
>> + goto out;
>
> This will try to release the not-acquired lock.
I will correct this.
>
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + /* obtain the T cold value */
>> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> +
>> + if (t_hot < t_cold) {
>> + count = -EINVAL;
>> + goto out;
>
> Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> change order order well defined or even possible. Applications should not have to bother about this.
The hardware behavior is like this. As long as the temperature is below
t_hot no interrupts are fired. Once the temperature increases above
t_hot we get an
interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
interrupt only when the temperature drops below the t_cold value. Hence
setting the t_cold higher than t_hot will mess up the state machine.
t_hot value should be greater than t_cold value.
>
>> + }
>> +
>> + /* write the new t_hot value */
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
>> + reg_val |= (t_hot <<
>> + __ffs(temp_sensor->registers->threshold_thot_mask));
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Read the current temperature */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /*
>> + * If user sets the HIGH threshold(t_hot) greater than the current
>> + * temperature(temp) unmask the HOT interrupts
>> + */
>> + if (t_hot > temp) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * If current temperature is in-between the hot and cold thresholds,
>> + * Enable both masks.
>> + */
>> + if (temp > t_cold && temp < t_hot) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + OMAP4460_BGAP_CTRL_OFFSET);
>
> Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
Ok. I will change this.
>
>> + }
>> + /*
>> + * else no need to do anything since HW will immediately compare
>> + * the new threshold and generate interrupt accordingly
>> + */
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return count;
>> +}
>> +
>> +static ssize_t show_temp_max_hyst(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 temp;
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>
> This lock would only make sense if threshold_tcold_mask can change, and if that change
> would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
> Besides, the code in show_temp_max() is almost the same and does not use the lock.
The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
ISR function. It is better to protect with mutex. I will add that in
required places.
>
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
>> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid value\n");
>> + return -EDOM;
>
> "Math argument out of domain of func" does not make sense.
> Unless you don't know anything better, use EIO (I/O Error). Not very specific,
> but at least not misleading.
Out of range i assumed this was the closest error value. I will use EIO.
>
> Besides, the log message is unnecessary. The user is informed with -EIO, and the admin
> won't be able to do anything useful with "invalid value".
Ok. I will return -EIO and eliminate the log message.
>
>> + }
>> +
>> + temp = adc_to_temp_conversion(temp);
>> +
>> + return snprintf(buf, 16, "%d\n", temp);
>> +}
>> +
>> +static ssize_t set_temp_max_hyst(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 reg_val, t_hot, t_cold, temp;
>> + long val;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>
> This will try to release the not acquired lock.
I will correct this.
>
>> + }
>> +
>> + t_cold = temp_to_adc_conversion(val);
>
> Bad error return check; same as above.
Ok. I will correct this.
>
>> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + /* obtain the T HOT value */
>> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
>> + __ffs(temp_sensor->registers->threshold_thot_mask);
>> +
>> + if (t_cold > t_hot) {
>
> Same concern as above. Change order is left to application which should not be bothered.
>
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + /* write the new t_cold value */
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
>> + reg_val |= t_cold <<
>> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Read the current temperature */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /*
>> + * If user sets the LOW threshold(t_cold) lower than the current
>> + * temperature(temp) unmask the COLD interrupts
>> + */
>> + if (t_cold < temp) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * If current temperature is in-between the hot and cold thresholds,
>> + * Enable both masks.
>> + */
>> + if (temp < t_hot && temp > t_cold) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * else no need to do anything since HW will immediately compare
>> + * the new threshold and generate interrupt accordingly
>> + */
>
> Would be nice if you could unify the interrupt enable code in a single function.
Ok. I will have a function for this.
>
>> +
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return count;
>> +}
>> +
>> +static ssize_t show_update_rate(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 temp = 0, ret = 0;
>> +
> No need to initialize temp.
> ret is u32, which doesn't seem to be a good type to use for negative values.
Oops yes. I will correct this.
>
>> +
>> + if (!temp_sensor->clk_rate) {
>> + dev_err(dev, "clk_rate is NULL\n");
>> + ret = -EDOM;
>
> Same comment as above (this is not a math error). And you don't have to check clk_rate anyway,
> since it is set in probe, and probe bails out if it is not set.
Ok
>
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>
> As with other show locks, this one would only make sense if counter_mask can change during runtime,
> and if that change would be protected by the mutex. This is not the case, thus the lock is unnecessary.
Counter value can be altered runtime. A lock is needed in both the cases.
I will add it.
>
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + temp = (temp & temp_sensor->registers->counter_mask) >>
>> + __ffs(temp_sensor->registers->counter_mask);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> + temp = temp * 1000 / temp_sensor->clk_rate;
>> +
>> +out:
>> + if (!ret)
>> + return sprintf(buf, "%d\n", temp);
>> +
>> + return ret;
>> +}
>> +
>> +static ssize_t set_update_rate(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 reg_val;
>> + long val;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + val *= temp_sensor->clk_rate / 1000;
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> +
>> + reg_val &= ~temp_sensor->registers->counter_mask;
>> + reg_val |= val;
>
> Sure you want to accept any value (including negative ones) here ?
> val is not shifted, and not masked against counter_mask, meaning it can write
> all bits of the register. That doesn't sound right.
I will have a check.
>
> It would make sense to call omap_configure_temp_sensor_counter() instead of duplicating
> the set functionality.
Yes I will make use of that.
>
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_counter);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> +out:
>> + return count;
>> +}
>> +
>> +static int omap_temp_sensor_read_temp(struct device *dev,
>> + struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + int temp, ret = 0;
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>
> Unless bgap_dtemp_mask can change during runtime, and that change is protected by the mutex,
> this lock is unnecessary.
It is read only and is updated by hardware. Change cannot be protected by mutex.
>
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /* look up for temperature in the table and return the temperature */
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid adc code reported %d", temp);
>> + ret = -EDOM;
>
> Another wrong use of EDOM, and another value-free error message.
Ok. I will use -EIO and drop the error message.
>
>> + goto out;
>> + }
>> +
>> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
>> +
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> + if (!ret)
>> + return sprintf(buf, "%d\n", temp);
>> +
>> + return ret;
>> +}
>> +
>> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, omap_temp_sensor_read_temp,
>> + NULL, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
>> + set_temp_max, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_max_hyst,
>> + set_temp_max_hyst, 0);
>> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO, show_update_rate,
>> + set_update_rate, 0);
>> +
>
> ABI is update_interval. Please use it.
Ok.
>
>> +static struct attribute *omap_temp_sensor_attributes[] = {
>> + &sensor_dev_attr_temp1_input.dev_attr.attr,
>> + &sensor_dev_attr_temp1_max.dev_attr.attr,
>> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
>> + &sensor_dev_attr_update_rate.dev_attr.attr,
>> + NULL
>> +};
>> +
>> +static const struct attribute_group omap_temp_sensor_group = {
>> + .attrs = omap_temp_sensor_attributes,
>> +};
>> +
>> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor *temp_sensor)
>> +{
>> + u32 ret = 0;
>> +
>> + if (temp_sensor->clk_on) {
>> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
>> + goto out;
>> + }
>> +
>> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
>> + if (ret < 0) {
>> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp_sensor->clk_on = 1;
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>
> Completely unnecessary lock.
Ok
>
>> +out:
>> + return ret;
>> +}
>> +
>> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
>
> Return code is not used anywhere, why bother providing one ?
It is not checked in the error path. I can make it void.
>
>> +{
>> + u32 ret = 0;
>> +
>> + if (!temp_sensor->clk_on) {
>> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
>> + goto out;
>
> ... and since you ignore the error anyway, why log it ?
Ok. I will remove the log message.
>
>> + }
>> +
>> + /* Gate the clock */
>> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
>> + if (ret < 0) {
>> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp_sensor->clk_on = 0;
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>
> Completely unnecessary lock.
Ok
>
>> +out:
>> + return ret;
>> +}
>> +
>> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
>> +{
>> + struct omap_temp_sensor *temp_sensor;
>> + int t_hot, t_cold, temp;
>> +
>> + temp_sensor = data;
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> +
>> + /* Read the status of t_hot */
>> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_status)
>> + & temp_sensor->registers->status_hot_mask;
>> +
>> + /* Read the status of t_cold */
>> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_status)
>> + & temp_sensor->registers->status_cold_mask;
>> +
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + /*
>> + * One TALERT interrupt: Two sources
>> + * If the interrupt is due to t_hot then mask t_hot and
>> + * and unmask t_cold else mask t_cold and unmask t_hot
>> + */
>> + if (t_hot) {
>> + temp &= ~temp_sensor->registers->mask_hot_mask;
>> + temp |= temp_sensor->registers->mask_cold_mask;
>> + } else if (t_cold) {
>> + temp &= ~temp_sensor->registers->mask_cold_mask;
>> + temp |= temp_sensor->registers->mask_hot_mask;
>> + }
>> +
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> +
>> + /* kobject_uvent to user space telling thermal threshold crossed */
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
>> +
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
>> +{
>> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
>> + struct omap_temp_sensor *temp_sensor;
>> + struct resource *mem;
>> + int ret = 0;
>> + int val, clk_rate;
>> + u32 max_freq, min_freq;
>> +
>> + if (!pdata) {
>> + dev_err(&pdev->dev, "platform data missing\n");
>> + return -EINVAL;
>> + }
>> +
>> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
>> + if (!temp_sensor)
>> + return -ENOMEM;
>> +
>
> You have error messages all over the place, Why not here ?
Ok. I will add an error message here.
>
>> + mutex_init(&temp_sensor->sensor_mutex);
>> +
>> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!mem) {
>> + dev_err(&pdev->dev, "no mem resource\n");
>> + ret = -ENOMEM;
>> + goto plat_res_err;
>> + }
>> +
>
> If you try to get the resource before allocating the memory, you don't have to release
> the memory if the platform resource is missing.
Ok. Here if i fail i am releasing temp_sensor memory which
has been allocated.
>
>> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
>> + if (temp_sensor->irq < 0) {
>> + dev_err(&pdev->dev, "get_irq_byname failed\n");
>> + ret = temp_sensor->irq;
>> + goto plat_res_err;
>> + }
>> +
>> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>> + temp_sensor->clock = NULL;
>> + temp_sensor->registers = pdata->registers;
>> + temp_sensor->hwmon_dev = &pdev->dev;
>> +
>> + if (pdata->max_freq && pdata->min_freq) {
>> + max_freq = pdata->max_freq;
>> + min_freq = pdata->min_freq;
>> + } else {
>> + max_freq = MAX_FREQ;
>> + min_freq = MIN_FREQ;
>> + }
>> +
>> + pm_runtime_enable(&pdev->dev);
>> + pm_runtime_irq_safe(&pdev->dev);
>> +
>> + /*
>> + * check if the efuse has a non-zero value if not
>> + * it is an untrimmed sample and the temperatures
>> + * may not be accurate
>> + */
>> +
>> + if (omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_efuse)) {
>> + temp_sensor->is_efuse_valid = 1;
>
> is_efuse_valid is not used anywhere. Might as well drop it.
Ok
>
>> + dev_dbg(temp_sensor->hwmon_dev,
>> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
>
> dev_info might be better here.
Ok.
>
>> + }
>> +
>> + dev_set_drvdata(&pdev->dev, temp_sensor);
>> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
>> + if (IS_ERR(temp_sensor->clock)) {
>> + ret = PTR_ERR(temp_sensor->clock);
>> + dev_err(temp_sensor->hwmon_dev,
>> + "unable to get fclk: %d\n", ret);
>> + goto plat_res_err;
>> + }
>> +
>> + ret = omap_temp_sensor_clk_enable(temp_sensor);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
>
> omap_temp_sensor_clk_enable() already generates error messages.
Ok. I will remove this.
>
>> + goto clken_err;
>> + }
>> +
>> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
>> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
>> + dev_err(&pdev->dev, "Error round rate\n");
>> + ret = -EDOM;
>
> EDOM is wrong. Please use ENODEV.
Ok
>
> The error log doesn't really provide anything useful to the administrator.
> Either add parameters, or drop it.
Ok
>
>> + goto clken_err;
>> + }
>> +
>> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Cannot set clock rate\n");
>> + goto clken_err;
>> + }
>> +
>> + temp_sensor->clk_rate = clk_rate;
>> + omap_enable_continuous_mode(temp_sensor, 1);
>> + omap_configure_temp_sensor_thresholds(temp_sensor);
>> + /* 1 ms */
>> + omap_configure_temp_sensor_counter(temp_sensor, 1);
>
> If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
> 1ms would be temp_sensor->clk_rate / 1000.
Yes! Wrong comment. It is configured to start the temperature conversion.
It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
>
>> +
>> + /* Wait till the first conversion is done wait for at least 1ms */
>> + usleep_range(1000, 2000);
>> +
>> + /* Read the temperature once due to hw issue*/
>> + omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> +
>> + /* Set 2 seconds time as default counter */
>> + omap_configure_temp_sensor_counter(temp_sensor,
>> + temp_sensor->clk_rate * 2);
>> +
>> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
>> + if (IS_ERR(temp_sensor->hwmon_dev)) {
>> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
>> + ret = PTR_ERR(temp_sensor->hwmon_dev);
>> + goto hwmon_reg_err;
>> + }
>> +
>> + ret = sysfs_create_group(&pdev->dev.kobj,
>> + &omap_temp_sensor_group);
>
> one line is sufficient here.
Ok.
>
>> + if (ret) {
>> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> + goto sysfs_create_err;
>> + }
>> +
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
>> +
>
> No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
Yes i will remove this.
>
>> + ret = request_threaded_irq(temp_sensor->irq, NULL,
>> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> + "temp_sensor", temp_sensor);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
>> + goto req_irq_err;
>> + }
>> +
>> + /* unmask the T_COLD and unmask T_HOT at init */
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + val |= temp_sensor->registers->mask_cold_mask
>> + | temp_sensor->registers->mask_hot_mask;
>> +
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> +
> This is racy. From Documentation/hwmon/submitting-patches:
I read it. If i enable the interrupts before i have the sysfs
infrastructure ready.
I am likely to miss out on the uevent notification if the interrupt
occurs as soon as
i unmask. Correct me if my understanding is wrong.
>
> * Make sure there are no race conditions in the probe function. Specifically,
> completely initialize your chip first, then create sysfs entries and register
> with the hwmon subsystem.
>
>> + return 0;
>> +
>> +req_irq_err:
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
>
> Same as before; why is this needed here but not in any other hwmon driver ?
Ok. I will remove this.
>
>> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
>> + &omap_temp_sensor_group);
>> +sysfs_create_err:
>> + hwmon_device_unregister(&pdev->dev);
>> +hwmon_reg_err:
>> + omap_temp_sensor_clk_disable(temp_sensor);
>> +clken_err:
>> + clk_put(temp_sensor->clock);
>> +plat_res_err:
>> + dev_set_drvdata(&pdev->dev, NULL);
>> + mutex_destroy(&temp_sensor->sensor_mutex);
>> + kfree(temp_sensor);
>> + return ret;
>> +}
>> +
>> +static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
>> +
>> + hwmon_device_unregister(&pdev->dev);
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
>
> ... and again.
Ok. I will remove this.
>
>> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
>> + &omap_temp_sensor_group);
>> + omap_temp_sensor_clk_disable(temp_sensor);
>> + free_irq(temp_sensor->irq, temp_sensor);
>> + clk_put(temp_sensor->clock);
>> + dev_set_drvdata(&pdev->dev, NULL);
>> + mutex_destroy(&temp_sensor->sensor_mutex);
>> + kfree(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static void omap_temp_sensor_save_ctxt(struct omap_temp_sensor *temp_sensor)
>> +{
>> + temp_sensor->temp_sensor_ctrl = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp_sensor->bg_ctrl = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + temp_sensor->bg_counter = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + temp_sensor->bg_threshold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp_sensor->temp_sensor_tshut_threshold =
>> + omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static void omap_temp_sensor_restore_ctxt(struct omap_temp_sensor *temp_sensor)
>> +{
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->temp_sensor_ctrl,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_ctrl,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_counter,
>> + temp_sensor->registers->bgap_counter);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_threshold,
>> + temp_sensor->registers->bgap_threshold);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->temp_sensor_tshut_threshold,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static int omap_temp_sensor_suspend(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_save_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_resume(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_restore_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_runtime_suspend(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_save_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_runtime_resume(struct device *dev)
>> +{
>> + static int context_loss_count;
>> + int temp;
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + temp = omap_device_get_context_loss_count(to_platform_device(dev));
>> +
>> + if (temp != context_loss_count && context_loss_count != 0)
>> + omap_temp_sensor_restore_ctxt(temp_sensor);
>> +
>> + context_loss_count = temp;
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_idle(struct device *dev)
>> +{
>> + return 0;
>> +}
>> +
>> +static const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
>> + SET_SYSTEM_SLEEP_PM_OPS(omap_temp_sensor_suspend,
>> + omap_temp_sensor_resume)
>> + SET_RUNTIME_PM_OPS(omap_temp_sensor_runtime_suspend,
>> + omap_temp_sensor_runtime_resume, omap_temp_sensor_idle)
>> +};
>> +
>> +#define DEV_PM_OPS (&omap_temp_sensor_dev_pm_ops)
>> +#else
>> +#define DEV_PM_OPS NULL
>> +#endif
>> +
>> +static struct platform_driver omap_temp_sensor_driver = {
>> + .probe = omap_temp_sensor_probe,
>> + .remove = omap_temp_sensor_remove,
>> + .driver = {
>> + .name = "omap_temp_sensor",
>> + .pm = DEV_PM_OPS,
>> + },
>> +};
>> +
>> +int __init omap_temp_sensor_init(void)
>> +{
>> + return platform_driver_register(&omap_temp_sensor_driver);
>> +}
>> +module_init(omap_temp_sensor_init);
>> +
>> +static void __exit omap_temp_sensor_exit(void)
>> +{
>> + platform_driver_unregister(&omap_temp_sensor_driver);
>> +}
>> +module_exit(omap_temp_sensor_exit);
>> +
>> +MODULE_DESCRIPTION("OMAP446X temperature sensor Driver");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:" DRIVER_NAME);
>> +MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
>> --
>> 1.7.0.4
>>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 10:30 ` J, KEERTHY
@ 2011-08-25 14:06 ` Guenter Roeck
2011-08-25 15:56 ` [lm-sensors] " Guenter Roeck
2011-08-25 16:04 ` J, KEERTHY
0 siblings, 2 replies; 19+ messages in thread
From: Guenter Roeck @ 2011-08-25 14:06 UTC (permalink / raw)
To: J, KEERTHY
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
> On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
> <guenter.roeck@ericsson.com> wrote:
> > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> >> On chip temperature sensor driver. The driver monitors the temperature of
> >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> >> the temperature crosses user defined thresholds via kobject_uevent interface.
> >> The user is allowed to configure the temperature thresholds vis sysfs nodes
> >> exposed using hwmon interface.
> >>
> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> >> Cc: Jean Delvare <khali@linux-fr.org>
> >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> >> Cc: lm-sensors@lm-sensors.org
> >
> > Partial review only. Too many concerns, and after a while I tend to loose track.
> >
> >> ---
> >> Documentation/hwmon/omap_temp_sensor | 27 +
> >> drivers/hwmon/Kconfig | 11 +
> >> drivers/hwmon/Makefile | 1 +
> >> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
> >> 4 files changed, 972 insertions(+), 0 deletions(-)
> >> create mode 100644 Documentation/hwmon/omap_temp_sensor
> >> create mode 100644 drivers/hwmon/omap_temp_sensor.c
> >>
[ ... ]
> >> +/* Sysfs hook functions */
> >> +
> >> +static ssize_t show_temp_max(struct device *dev,
> >> + struct device_attribute *devattr, char *buf)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + int temp;
> >> +
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
> >> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
> >> +
> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> >> + dev_err(dev, "invalid value\n");
> >> + return -EDOM;
> >
> > Please don't use EDOM, and drop the error message.
>
> The temperature is out of range. Should i use EIO?
>
It is out of range, but not due to a math error, but due to a bad reading from the chip
or due to a chip failure. EIO is ok.
> >
> >> + }
> >> +
> >> + temp = adc_to_temp_conversion(temp);
> >> +
> >> + return snprintf(buf, 16, "%d\n", temp);
> >> +}
> >> +
> >> +static ssize_t set_temp_max(struct device *dev,
> >> + struct device_attribute *devattr,
> >> + const char *buf, size_t count)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + long val;
> >> + u32 reg_val, t_cold, t_hot, temp;
> >> +
> >> + if (strict_strtol(buf, 10, &val)) {
> >> + count = -EINVAL;
> >> + goto out;
> >
> > This will try to release the not-acquired lock.
>
> I will correct this.
>
> >
> >> + }
> >> +
> >> + t_hot = temp_to_adc_conversion(val);
> >
> > Bad error return check. Negative on error. Should be
> > if (t_hot < 0)
> > return t_hot;
>
> Ok.
>
> >
> >> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
> >
> > Unnecessary (( ))
>
> This check is unnecessary with the negative check. I will remove.
>
> >
> >> + count = -EINVAL;
> >> + goto out;
> >
> > This will try to release the not-acquired lock.
>
> I will correct this.
>
> >
> >> + }
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> + /* obtain the T cold value */
> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> +
> >> + if (t_hot < t_cold) {
> >> + count = -EINVAL;
> >> + goto out;
> >
> > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> > change order order well defined or even possible. Applications should not have to bother about this.
>
> The hardware behavior is like this. As long as the temperature is below
> t_hot no interrupts are fired. Once the temperature increases above
> t_hot we get an
> interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
> in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
> interrupt only when the temperature drops below the t_cold value. Hence
> setting the t_cold higher than t_hot will mess up the state machine.
>
> t_hot value should be greater than t_cold value.
>
One option would be to update t_cold (max_hyst) automatically in that case.
Problem here is that you expect the aplication to know, depending on the current
values of (max, max_hyst), how to update both limits in order. That is not a reasonable
expectation.
> >
> >> + }
> >> +
> >> + /* write the new t_hot value */
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
> >> + reg_val |= (t_hot <<
> >> + __ffs(temp_sensor->registers->threshold_thot_mask));
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_threshold);
> >> +
> >> + /* Read the current temperature */
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> >> +
> >> + /*
> >> + * If user sets the HIGH threshold(t_hot) greater than the current
> >> + * temperature(temp) unmask the HOT interrupts
> >> + */
> >> + if (t_hot > temp) {
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + }
> >> +
> >> + /*
> >> + * If current temperature is in-between the hot and cold thresholds,
> >> + * Enable both masks.
> >> + */
> >> + if (temp > t_cold && temp < t_hot) {
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + OMAP4460_BGAP_CTRL_OFFSET);
> >
> > Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
>
> Ok. I will change this.
>
> >
> >> + }
> >> + /*
> >> + * else no need to do anything since HW will immediately compare
> >> + * the new threshold and generate interrupt accordingly
> >> + */
> >> +out:
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >> + return count;
> >> +}
> >> +
> >> +static ssize_t show_temp_max_hyst(struct device *dev,
> >> + struct device_attribute *devattr, char *buf)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + u32 temp;
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >
> > This lock would only make sense if threshold_tcold_mask can change, and if that change
> > would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
> > Besides, the code in show_temp_max() is almost the same and does not use the lock.
>
> The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
> ISR function. It is better to protect with mutex. I will add that in
> required places.
>
Reeally ? I seem to be blind. I searched for threshold_tcold_mask in the patch but
did not see where it is changed. Can you point me to the code ?
If it is changed outside the driver, you have a real problem, since there is no guarantee
that the mask is not changed from outside the driver, by code not protected by the mutex.
And if read functions have the side effect of changing such values, there should really
be a note somewhere to make people aware of it. I'd call that side effect programming,
and would argue it is a really bad idea.
> >
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> >> + dev_err(dev, "invalid value\n");
> >> + return -EDOM;
> >
> > "Math argument out of domain of func" does not make sense.
> > Unless you don't know anything better, use EIO (I/O Error). Not very specific,
> > but at least not misleading.
>
> Out of range i assumed this was the closest error value. I will use EIO.
>
It is not a math error, though.
> >
> > Besides, the log message is unnecessary. The user is informed with -EIO, and the admin
> > won't be able to do anything useful with "invalid value".
>
> Ok. I will return -EIO and eliminate the log message.
>
> >
> >> + }
> >> +
> >> + temp = adc_to_temp_conversion(temp);
> >> +
> >> + return snprintf(buf, 16, "%d\n", temp);
> >> +}
> >> +
> >> +static ssize_t set_temp_max_hyst(struct device *dev,
> >> + struct device_attribute *devattr,
> >> + const char *buf, size_t count)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + u32 reg_val, t_hot, t_cold, temp;
> >> + long val;
> >> +
> >> + if (strict_strtol(buf, 10, &val)) {
> >> + count = -EINVAL;
> >> + goto out;
> >
> > This will try to release the not acquired lock.
>
> I will correct this.
>
> >
> >> + }
> >> +
> >> + t_cold = temp_to_adc_conversion(val);
> >
> > Bad error return check; same as above.
>
> Ok. I will correct this.
>
> >
> >> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
> >> + count = -EINVAL;
> >> + goto out;
> >> + }
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> + /* obtain the T HOT value */
> >> + t_hot = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
> >> + __ffs(temp_sensor->registers->threshold_thot_mask);
> >> +
> >> + if (t_cold > t_hot) {
> >
> > Same concern as above. Change order is left to application which should not be bothered.
> >
> >> + count = -EINVAL;
> >> + goto out;
> >> + }
> >> +
> >> + /* write the new t_cold value */
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_threshold);
> >> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
> >> + reg_val |= t_cold <<
> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_threshold);
> >> +
> >> + /* Read the current temperature */
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> >> +
> >> + /*
> >> + * If user sets the LOW threshold(t_cold) lower than the current
> >> + * temperature(temp) unmask the COLD interrupts
> >> + */
> >> + if (t_cold < temp) {
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + }
> >> +
> >> + /*
> >> + * If current temperature is in-between the hot and cold thresholds,
> >> + * Enable both masks.
> >> + */
> >> + if (temp < t_hot && temp > t_cold) {
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + }
> >> +
> >> + /*
> >> + * else no need to do anything since HW will immediately compare
> >> + * the new threshold and generate interrupt accordingly
> >> + */
> >
> > Would be nice if you could unify the interrupt enable code in a single function.
>
> Ok. I will have a function for this.
>
> >
> >> +
> >> +out:
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >> + return count;
> >> +}
> >> +
> >> +static ssize_t show_update_rate(struct device *dev,
> >> + struct device_attribute *devattr, char *buf)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + u32 temp = 0, ret = 0;
> >> +
> > No need to initialize temp.
> > ret is u32, which doesn't seem to be a good type to use for negative values.
>
> Oops yes. I will correct this.
>
> >
> >> +
> >> + if (!temp_sensor->clk_rate) {
> >> + dev_err(dev, "clk_rate is NULL\n");
> >> + ret = -EDOM;
> >
> > Same comment as above (this is not a math error). And you don't have to check clk_rate anyway,
> > since it is set in probe, and probe bails out if it is not set.
>
> Ok
>
> >
> >> + goto out;
> >> + }
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >
> > As with other show locks, this one would only make sense if counter_mask can change during runtime,
> > and if that change would be protected by the mutex. This is not the case, thus the lock is unnecessary.
>
> Counter value can be altered runtime. A lock is needed in both the cases.
> I will add it.
>
clk_rate does not change, counter_mask does not change, and reading a single value
doesn't need a mutex. Am I missing something ?
> >
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_counter);
> >> + temp = (temp & temp_sensor->registers->counter_mask) >>
> >> + __ffs(temp_sensor->registers->counter_mask);
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> + temp = temp * 1000 / temp_sensor->clk_rate;
> >> +
> >> +out:
> >> + if (!ret)
> >> + return sprintf(buf, "%d\n", temp);
> >> +
> >> + return ret;
> >> +}
> >> +
> >> +static ssize_t set_update_rate(struct device *dev,
> >> + struct device_attribute *devattr,
> >> + const char *buf, size_t count)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + u32 reg_val;
> >> + long val;
> >> +
> >> + if (strict_strtol(buf, 10, &val)) {
> >> + count = -EINVAL;
> >> + goto out;
> >> + }
> >> +
> >> + val *= temp_sensor->clk_rate / 1000;
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_counter);
> >> +
> >> + reg_val &= ~temp_sensor->registers->counter_mask;
> >> + reg_val |= val;
> >
> > Sure you want to accept any value (including negative ones) here ?
> > val is not shifted, and not masked against counter_mask, meaning it can write
> > all bits of the register. That doesn't sound right.
>
> I will have a check.
>
> >
> > It would make sense to call omap_configure_temp_sensor_counter() instead of duplicating
> > the set functionality.
>
> Yes I will make use of that.
>
> >
> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> + temp_sensor->registers->bgap_counter);
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >> +out:
> >> + return count;
> >> +}
> >> +
> >> +static int omap_temp_sensor_read_temp(struct device *dev,
> >> + struct device_attribute *devattr,
> >> + char *buf)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> + int temp, ret = 0;
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >
> > Unless bgap_dtemp_mask can change during runtime, and that change is protected by the mutex,
> > this lock is unnecessary.
>
> It is read only and is updated by hardware. Change cannot be protected by mutex.
>
> >
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> >> +
> >> + /* look up for temperature in the table and return the temperature */
> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> >> + dev_err(dev, "invalid adc code reported %d", temp);
> >> + ret = -EDOM;
> >
> > Another wrong use of EDOM, and another value-free error message.
>
> Ok. I will use -EIO and drop the error message.
>
> >
> >> + goto out;
> >> + }
> >> +
> >> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
> >> +
> >> +out:
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> + if (!ret)
> >> + return sprintf(buf, "%d\n", temp);
> >> +
> >> + return ret;
> >> +}
> >> +
> >> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, omap_temp_sensor_read_temp,
> >> + NULL, 0);
> >> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
> >> + set_temp_max, 0);
> >> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_max_hyst,
> >> + set_temp_max_hyst, 0);
> >> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO, show_update_rate,
> >> + set_update_rate, 0);
> >> +
> >
> > ABI is update_interval. Please use it.
>
> Ok.
>
> >
> >> +static struct attribute *omap_temp_sensor_attributes[] = {
> >> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> >> + &sensor_dev_attr_temp1_max.dev_attr.attr,
> >> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
> >> + &sensor_dev_attr_update_rate.dev_attr.attr,
> >> + NULL
> >> +};
> >> +
> >> +static const struct attribute_group omap_temp_sensor_group = {
> >> + .attrs = omap_temp_sensor_attributes,
> >> +};
> >> +
> >> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor *temp_sensor)
> >> +{
> >> + u32 ret = 0;
> >> +
> >> + if (temp_sensor->clk_on) {
> >> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
> >> + goto out;
> >> + }
> >> +
> >> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
> >> + if (ret < 0) {
> >> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
> >> + goto out;
> >> + }
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> + temp_sensor->clk_on = 1;
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >
> > Completely unnecessary lock.
>
> Ok
>
> >
> >> +out:
> >> + return ret;
> >> +}
> >> +
> >> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
> >
> > Return code is not used anywhere, why bother providing one ?
>
> It is not checked in the error path. I can make it void.
>
> >
> >> +{
> >> + u32 ret = 0;
> >> +
> >> + if (!temp_sensor->clk_on) {
> >> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
> >> + goto out;
> >
> > ... and since you ignore the error anyway, why log it ?
>
> Ok. I will remove the log message.
>
> >
> >> + }
> >> +
> >> + /* Gate the clock */
> >> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
> >> + if (ret < 0) {
> >> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
> >> + goto out;
> >> + }
> >> +
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> + temp_sensor->clk_on = 0;
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >
> > Completely unnecessary lock.
>
> Ok
>
> >
> >> +out:
> >> + return ret;
> >> +}
> >> +
> >> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
> >> +{
> >> + struct omap_temp_sensor *temp_sensor;
> >> + int t_hot, t_cold, temp;
> >> +
> >> + temp_sensor = data;
> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> +
> >> + /* Read the status of t_hot */
> >> + t_hot = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_status)
> >> + & temp_sensor->registers->status_hot_mask;
> >> +
> >> + /* Read the status of t_cold */
> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_status)
> >> + & temp_sensor->registers->status_cold_mask;
> >> +
> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + /*
> >> + * One TALERT interrupt: Two sources
> >> + * If the interrupt is due to t_hot then mask t_hot and
> >> + * and unmask t_cold else mask t_cold and unmask t_hot
> >> + */
> >> + if (t_hot) {
> >> + temp &= ~temp_sensor->registers->mask_hot_mask;
> >> + temp |= temp_sensor->registers->mask_cold_mask;
> >> + } else if (t_cold) {
> >> + temp &= ~temp_sensor->registers->mask_cold_mask;
> >> + temp |= temp_sensor->registers->mask_hot_mask;
> >> + }
> >> +
> >> + omap_temp_sensor_writel(temp_sensor, temp,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> +
> >> + /* kobject_uvent to user space telling thermal threshold crossed */
> >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
> >> +
> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> +
> >> + return IRQ_HANDLED;
> >> +}
> >> +
> >> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
> >> +{
> >> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
> >> + struct omap_temp_sensor *temp_sensor;
> >> + struct resource *mem;
> >> + int ret = 0;
> >> + int val, clk_rate;
> >> + u32 max_freq, min_freq;
> >> +
> >> + if (!pdata) {
> >> + dev_err(&pdev->dev, "platform data missing\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
> >> + if (!temp_sensor)
> >> + return -ENOMEM;
> >> +
> >
> > You have error messages all over the place, Why not here ?
>
> Ok. I will add an error message here.
>
> >
> >> + mutex_init(&temp_sensor->sensor_mutex);
> >> +
> >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> + if (!mem) {
> >> + dev_err(&pdev->dev, "no mem resource\n");
> >> + ret = -ENOMEM;
> >> + goto plat_res_err;
> >> + }
> >> +
> >
> > If you try to get the resource before allocating the memory, you don't have to release
> > the memory if the platform resource is missing.
>
> Ok. Here if i fail i am releasing temp_sensor memory which
> has been allocated.
>
> >
> >> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> >> + if (temp_sensor->irq < 0) {
> >> + dev_err(&pdev->dev, "get_irq_byname failed\n");
> >> + ret = temp_sensor->irq;
> >> + goto plat_res_err;
> >> + }
> >> +
> >> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
> >> + temp_sensor->clock = NULL;
> >> + temp_sensor->registers = pdata->registers;
> >> + temp_sensor->hwmon_dev = &pdev->dev;
> >> +
> >> + if (pdata->max_freq && pdata->min_freq) {
> >> + max_freq = pdata->max_freq;
> >> + min_freq = pdata->min_freq;
> >> + } else {
> >> + max_freq = MAX_FREQ;
> >> + min_freq = MIN_FREQ;
> >> + }
> >> +
> >> + pm_runtime_enable(&pdev->dev);
> >> + pm_runtime_irq_safe(&pdev->dev);
> >> +
> >> + /*
> >> + * check if the efuse has a non-zero value if not
> >> + * it is an untrimmed sample and the temperatures
> >> + * may not be accurate
> >> + */
> >> +
> >> + if (omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_efuse)) {
> >> + temp_sensor->is_efuse_valid = 1;
> >
> > is_efuse_valid is not used anywhere. Might as well drop it.
>
> Ok
>
> >
> >> + dev_dbg(temp_sensor->hwmon_dev,
> >> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
> >
> > dev_info might be better here.
>
> Ok.
>
> >
> >> + }
> >> +
> >> + dev_set_drvdata(&pdev->dev, temp_sensor);
> >> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
> >> + if (IS_ERR(temp_sensor->clock)) {
> >> + ret = PTR_ERR(temp_sensor->clock);
> >> + dev_err(temp_sensor->hwmon_dev,
> >> + "unable to get fclk: %d\n", ret);
> >> + goto plat_res_err;
> >> + }
> >> +
> >> + ret = omap_temp_sensor_clk_enable(temp_sensor);
> >> + if (ret) {
> >> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
> >
> > omap_temp_sensor_clk_enable() already generates error messages.
>
> Ok. I will remove this.
>
> >
> >> + goto clken_err;
> >> + }
> >> +
> >> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
> >> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
> >> + dev_err(&pdev->dev, "Error round rate\n");
> >> + ret = -EDOM;
> >
> > EDOM is wrong. Please use ENODEV.
>
> Ok
>
> >
> > The error log doesn't really provide anything useful to the administrator.
> > Either add parameters, or drop it.
>
> Ok
>
> >
> >> + goto clken_err;
> >> + }
> >> +
> >> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
> >> + if (ret) {
> >> + dev_err(&pdev->dev, "Cannot set clock rate\n");
> >> + goto clken_err;
> >> + }
> >> +
> >> + temp_sensor->clk_rate = clk_rate;
> >> + omap_enable_continuous_mode(temp_sensor, 1);
> >> + omap_configure_temp_sensor_thresholds(temp_sensor);
> >> + /* 1 ms */
> >> + omap_configure_temp_sensor_counter(temp_sensor, 1);
> >
> > If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
> > 1ms would be temp_sensor->clk_rate / 1000.
>
> Yes! Wrong comment. It is configured to start the temperature conversion.
> It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
>
> >
> >> +
> >> + /* Wait till the first conversion is done wait for at least 1ms */
> >> + usleep_range(1000, 2000);
> >> +
> >> + /* Read the temperature once due to hw issue*/
> >> + omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> +
> >> + /* Set 2 seconds time as default counter */
> >> + omap_configure_temp_sensor_counter(temp_sensor,
> >> + temp_sensor->clk_rate * 2);
> >> +
> >> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> >> + if (IS_ERR(temp_sensor->hwmon_dev)) {
> >> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
> >> + ret = PTR_ERR(temp_sensor->hwmon_dev);
> >> + goto hwmon_reg_err;
> >> + }
> >> +
> >> + ret = sysfs_create_group(&pdev->dev.kobj,
> >> + &omap_temp_sensor_group);
> >
> > one line is sufficient here.
>
> Ok.
>
> >
> >> + if (ret) {
> >> + dev_err(&pdev->dev, "could not create sysfs files\n");
> >> + goto sysfs_create_err;
> >> + }
> >> +
> >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
> >> +
> >
> > No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
>
> Yes i will remove this.
>
> >
> >> + ret = request_threaded_irq(temp_sensor->irq, NULL,
> >> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> >> + "temp_sensor", temp_sensor);
> >> + if (ret) {
> >> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
> >> + goto req_irq_err;
> >> + }
> >> +
> >> + /* unmask the T_COLD and unmask T_HOT at init */
> >> + val = omap_temp_sensor_readl(temp_sensor,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> + val |= temp_sensor->registers->mask_cold_mask
> >> + | temp_sensor->registers->mask_hot_mask;
> >> +
> >> + omap_temp_sensor_writel(temp_sensor, val,
> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> +
> > This is racy. From Documentation/hwmon/submitting-patches:
>
> I read it. If i enable the interrupts before i have the sysfs
> infrastructure ready.
> I am likely to miss out on the uevent notification if the interrupt
> occurs as soon as
> i unmask. Correct me if my understanding is wrong.
>
See other email on sequence subject. I'll have to look into it in more detail.
later - no time right now ...
Guenter
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 14:06 ` Guenter Roeck
@ 2011-08-25 15:56 ` Guenter Roeck
2011-08-25 16:06 ` J, KEERTHY
2011-08-26 11:17 ` J, KEERTHY
2011-08-25 16:04 ` J, KEERTHY
1 sibling, 2 replies; 19+ messages in thread
From: Guenter Roeck @ 2011-08-25 15:56 UTC (permalink / raw)
To: J, KEERTHY; +Cc: linux-omap@vger.kernel.org, lm-sensors@lm-sensors.org
On Thu, 2011-08-25 at 10:06 -0400, Guenter Roeck wrote:
> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
> > On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
> > <guenter.roeck@ericsson.com> wrote:
> > > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> > >> On chip temperature sensor driver. The driver monitors the temperature of
> > >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> > >> the temperature crosses user defined thresholds via kobject_uevent interface.
> > >> The user is allowed to configure the temperature thresholds vis sysfs nodes
> > >> exposed using hwmon interface.
> > >>
> > >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> > >> Cc: Jean Delvare <khali@linux-fr.org>
> > >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> > >> Cc: lm-sensors@lm-sensors.org
> > >
[ ... ]
> >
> > >
> > >> + }
> > >> +
> > >> + mutex_lock(&temp_sensor->sensor_mutex);
> > >> + /* obtain the T cold value */
> > >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> > >> + temp_sensor->registers->bgap_threshold);
> > >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> > >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> > >> +
> > >> + if (t_hot < t_cold) {
> > >> + count = -EINVAL;
> > >> + goto out;
> > >
> > > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> > > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> > > change order order well defined or even possible. Applications should not have to bother about this.
> >
> > The hardware behavior is like this. As long as the temperature is below
> > t_hot no interrupts are fired. Once the temperature increases above
> > t_hot we get an
> > interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
> > in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
> > interrupt only when the temperature drops below the t_cold value. Hence
> > setting the t_cold higher than t_hot will mess up the state machine.
> >
> > t_hot value should be greater than t_cold value.
> >
> One option would be to update t_cold (max_hyst) automatically in that case.
>
> Problem here is that you expect the application to know, depending on the current
> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
> expectation.
>
One possible solution would be to have a single function to set both
t_cold and t_hot, and call it from both initialization code and from the
set functions. That would unify all the register setting and interrupt
enable code.
Regarding the actual values to set, you can (as an example) use the
following approach:
- If max is set, and t_hot < t_cold, adjust t_cold to the new value of
t_hot.
- if max_hyst is set, and t_cold > t_hot, set t_cold to the new value of
t_hot.
So, in other words, your new unified function would only need the
following simple validation:
if (t_cold > t_hot)
t_cold = t_hot;
[ ... ]
> > >> +
> > >> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
> > >> +{
> > >> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
> > >> + struct omap_temp_sensor *temp_sensor;
> > >> + struct resource *mem;
> > >> + int ret = 0;
> > >> + int val, clk_rate;
> > >> + u32 max_freq, min_freq;
> > >> +
> > >> + if (!pdata) {
> > >> + dev_err(&pdev->dev, "platform data missing\n");
> > >> + return -EINVAL;
> > >> + }
> > >> +
> > >> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
> > >> + if (!temp_sensor)
> > >> + return -ENOMEM;
> > >> +
> > >
> > > You have error messages all over the place, Why not here ?
> >
> > Ok. I will add an error message here.
> >
> > >
> > >> + mutex_init(&temp_sensor->sensor_mutex);
> > >> +
> > >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > >> + if (!mem) {
> > >> + dev_err(&pdev->dev, "no mem resource\n");
> > >> + ret = -ENOMEM;
> > >> + goto plat_res_err;
> > >> + }
> > >> +
> > >
> > > If you try to get the resource before allocating the memory, you don't have to release
> > > the memory if the platform resource is missing.
> >
> > Ok. Here if i fail i am releasing temp_sensor memory which
> > has been allocated.
> >
> > >
> > >> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> > >> + if (temp_sensor->irq < 0) {
> > >> + dev_err(&pdev->dev, "get_irq_byname failed\n");
> > >> + ret = temp_sensor->irq;
> > >> + goto plat_res_err;
> > >> + }
> > >> +
> > >> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
> > >> + temp_sensor->clock = NULL;
> > >> + temp_sensor->registers = pdata->registers;
> > >> + temp_sensor->hwmon_dev = &pdev->dev;
> > >> +
> > >> + if (pdata->max_freq && pdata->min_freq) {
> > >> + max_freq = pdata->max_freq;
> > >> + min_freq = pdata->min_freq;
> > >> + } else {
> > >> + max_freq = MAX_FREQ;
> > >> + min_freq = MIN_FREQ;
> > >> + }
> > >> +
> > >> + pm_runtime_enable(&pdev->dev);
> > >> + pm_runtime_irq_safe(&pdev->dev);
> > >> +
> > >> + /*
> > >> + * check if the efuse has a non-zero value if not
> > >> + * it is an untrimmed sample and the temperatures
> > >> + * may not be accurate
> > >> + */
> > >> +
> > >> + if (omap_temp_sensor_readl(temp_sensor,
> > >> + temp_sensor->registers->bgap_efuse)) {
> > >> + temp_sensor->is_efuse_valid = 1;
> > >
> > > is_efuse_valid is not used anywhere. Might as well drop it.
> >
> > Ok
> >
> > >
> > >> + dev_dbg(temp_sensor->hwmon_dev,
> > >> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
> > >
> > > dev_info might be better here.
> >
> > Ok.
> >
> > >
> > >> + }
> > >> +
> > >> + dev_set_drvdata(&pdev->dev, temp_sensor);
> > >> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
> > >> + if (IS_ERR(temp_sensor->clock)) {
> > >> + ret = PTR_ERR(temp_sensor->clock);
> > >> + dev_err(temp_sensor->hwmon_dev,
> > >> + "unable to get fclk: %d\n", ret);
> > >> + goto plat_res_err;
> > >> + }
> > >> +
> > >> + ret = omap_temp_sensor_clk_enable(temp_sensor);
> > >> + if (ret) {
> > >> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
> > >
> > > omap_temp_sensor_clk_enable() already generates error messages.
> >
> > Ok. I will remove this.
> >
> > >
> > >> + goto clken_err;
> > >> + }
> > >> +
> > >> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
> > >> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
> > >> + dev_err(&pdev->dev, "Error round rate\n");
> > >> + ret = -EDOM;
> > >
> > > EDOM is wrong. Please use ENODEV.
> >
> > Ok
> >
> > >
> > > The error log doesn't really provide anything useful to the administrator.
> > > Either add parameters, or drop it.
> >
> > Ok
> >
> > >
> > >> + goto clken_err;
> > >> + }
> > >> +
> > >> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
> > >> + if (ret) {
> > >> + dev_err(&pdev->dev, "Cannot set clock rate\n");
> > >> + goto clken_err;
> > >> + }
> > >> +
> > >> + temp_sensor->clk_rate = clk_rate;
> > >> + omap_enable_continuous_mode(temp_sensor, 1);
> > >> + omap_configure_temp_sensor_thresholds(temp_sensor);
> > >> + /* 1 ms */
> > >> + omap_configure_temp_sensor_counter(temp_sensor, 1);
> > >
> > > If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
> > > 1ms would be temp_sensor->clk_rate / 1000.
> >
> > Yes! Wrong comment. It is configured to start the temperature conversion.
> > It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
> >
> > >
> > >> +
> > >> + /* Wait till the first conversion is done wait for at least 1ms */
> > >> + usleep_range(1000, 2000);
> > >> +
> > >> + /* Read the temperature once due to hw issue*/
> > >> + omap_temp_sensor_readl(temp_sensor,
> > >> + temp_sensor->registers->temp_sensor_ctrl);
> > >> +
> > >> + /* Set 2 seconds time as default counter */
> > >> + omap_configure_temp_sensor_counter(temp_sensor,
> > >> + temp_sensor->clk_rate * 2);
> > >> +
> > >> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> > >> + if (IS_ERR(temp_sensor->hwmon_dev)) {
> > >> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
> > >> + ret = PTR_ERR(temp_sensor->hwmon_dev);
> > >> + goto hwmon_reg_err;
> > >> + }
> > >> +
> > >> + ret = sysfs_create_group(&pdev->dev.kobj,
> > >> + &omap_temp_sensor_group);
> > >
> > > one line is sufficient here.
> >
> > Ok.
> >
> > >
> > >> + if (ret) {
> > >> + dev_err(&pdev->dev, "could not create sysfs files\n");
> > >> + goto sysfs_create_err;
> > >> + }
> > >> +
> > >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
> > >> +
> > >
> > > No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
> >
> > Yes i will remove this.
> >
> > >
> > >> + ret = request_threaded_irq(temp_sensor->irq, NULL,
> > >> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> > >> + "temp_sensor", temp_sensor);
> > >> + if (ret) {
> > >> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
> > >> + goto req_irq_err;
> > >> + }
> > >> +
> > >> + /* unmask the T_COLD and unmask T_HOT at init */
> > >> + val = omap_temp_sensor_readl(temp_sensor,
> > >> + temp_sensor->registers->bgap_mask_ctrl);
> > >> + val |= temp_sensor->registers->mask_cold_mask
> > >> + | temp_sensor->registers->mask_hot_mask;
> > >> +
> > >> + omap_temp_sensor_writel(temp_sensor, val,
> > >> + temp_sensor->registers->bgap_mask_ctrl);
> > >> +
> > > This is racy. From Documentation/hwmon/submitting-patches:
> >
> > I read it. If i enable the interrupts before i have the sysfs
> > infrastructure ready.
> > I am likely to miss out on the uevent notification if the interrupt
> > occurs as soon as
> > i unmask. Correct me if my understanding is wrong.
> >
> See other email on sequence subject. I'll have to look into it in more detail.
> later - no time right now ...
Concerns:
- create sysfs entries first, then register with hwmon.
hwmon_device_register is usually the last call, made only after
everything is known to work.
- You can definitely request the interrupt before registering sysfs
entries
- temp_sensor->hwmon_dev is initially set to
temp_sensor->hwmon_dev = &pdev->dev;
then overwritten with
temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
This is, at the very least, odd and doesn't seem to make sense.
- Interrupt enable code (setting bgap_mask_ctrl) in probe function
occurs after sysfs files have been enabled, and the access is not mutex
protected. Thus, sysfs access can already happen, causing the main race
I was concerned about.
My suggestion is
- request interrupt prior to sysfs creation and hwmon registration.
- swap sysfs file creation and hwmon registration.
- Use the unified function I suggested above to set t_cold, t_hot, and
to enable interrupts as needed. Since that function will be mutex
protected, you can call it after hwmon registration, and avoid the race.
Also look into use of temp_sensor->hwmon_dev vs. &pdev->dev. That code
just doesn't look right.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 15:56 ` [lm-sensors] " Guenter Roeck
@ 2011-08-25 16:06 ` J, KEERTHY
2011-08-26 11:17 ` J, KEERTHY
1 sibling, 0 replies; 19+ messages in thread
From: J, KEERTHY @ 2011-08-25 16:06 UTC (permalink / raw)
To: guenter.roeck; +Cc: linux-omap@vger.kernel.org, lm-sensors@lm-sensors.org
On Thu, Aug 25, 2011 at 9:26 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Thu, 2011-08-25 at 10:06 -0400, Guenter Roeck wrote:
>> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
>> > On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
>> > <guenter.roeck@ericsson.com> wrote:
>> > > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> > >> On chip temperature sensor driver. The driver monitors the temperature of
>> > >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> > >> the temperature crosses user defined thresholds via kobject_uevent interface.
>> > >> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> > >> exposed using hwmon interface.
>> > >>
>> > >> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> > >> Cc: Jean Delvare <khali@linux-fr.org>
>> > >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> > >> Cc: lm-sensors@lm-sensors.org
>> > >
>
> [ ... ]
>
>
>> >
>> > >
>> > >> + }
>> > >> +
>> > >> + mutex_lock(&temp_sensor->sensor_mutex);
>> > >> + /* obtain the T cold value */
>> > >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_threshold);
>> > >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> > >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> > >> +
>> > >> + if (t_hot < t_cold) {
>> > >> + count = -EINVAL;
>> > >> + goto out;
>> > >
>> > > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
>> > > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
>> > > change order order well defined or even possible. Applications should not have to bother about this.
>> >
>> > The hardware behavior is like this. As long as the temperature is below
>> > t_hot no interrupts are fired. Once the temperature increases above
>> > t_hot we get an
>> > interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
>> > in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
>> > interrupt only when the temperature drops below the t_cold value. Hence
>> > setting the t_cold higher than t_hot will mess up the state machine.
>> >
>> > t_hot value should be greater than t_cold value.
>> >
>> One option would be to update t_cold (max_hyst) automatically in that case.
>>
>> Problem here is that you expect the application to know, depending on the current
>> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
>> expectation.
>>
> One possible solution would be to have a single function to set both
> t_cold and t_hot, and call it from both initialization code and from the
> set functions. That would unify all the register setting and interrupt
> enable code.
>
> Regarding the actual values to set, you can (as an example) use the
> following approach:
>
> - If max is set, and t_hot < t_cold, adjust t_cold to the new value of
> t_hot.
>
> - if max_hyst is set, and t_cold > t_hot, set t_cold to the new value of
> t_hot.
>
> So, in other words, your new unified function would only need the
> following simple validation:
>
> if (t_cold > t_hot)
> t_cold = t_hot;
>
> [ ... ]
>
>> > >> +
>> > >> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
>> > >> +{
>> > >> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
>> > >> + struct omap_temp_sensor *temp_sensor;
>> > >> + struct resource *mem;
>> > >> + int ret = 0;
>> > >> + int val, clk_rate;
>> > >> + u32 max_freq, min_freq;
>> > >> +
>> > >> + if (!pdata) {
>> > >> + dev_err(&pdev->dev, "platform data missing\n");
>> > >> + return -EINVAL;
>> > >> + }
>> > >> +
>> > >> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
>> > >> + if (!temp_sensor)
>> > >> + return -ENOMEM;
>> > >> +
>> > >
>> > > You have error messages all over the place, Why not here ?
>> >
>> > Ok. I will add an error message here.
>> >
>> > >
>> > >> + mutex_init(&temp_sensor->sensor_mutex);
>> > >> +
>> > >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> > >> + if (!mem) {
>> > >> + dev_err(&pdev->dev, "no mem resource\n");
>> > >> + ret = -ENOMEM;
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >
>> > > If you try to get the resource before allocating the memory, you don't have to release
>> > > the memory if the platform resource is missing.
>> >
>> > Ok. Here if i fail i am releasing temp_sensor memory which
>> > has been allocated.
>> >
>> > >
>> > >> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
>> > >> + if (temp_sensor->irq < 0) {
>> > >> + dev_err(&pdev->dev, "get_irq_byname failed\n");
>> > >> + ret = temp_sensor->irq;
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>> > >> + temp_sensor->clock = NULL;
>> > >> + temp_sensor->registers = pdata->registers;
>> > >> + temp_sensor->hwmon_dev = &pdev->dev;
>> > >> +
>> > >> + if (pdata->max_freq && pdata->min_freq) {
>> > >> + max_freq = pdata->max_freq;
>> > >> + min_freq = pdata->min_freq;
>> > >> + } else {
>> > >> + max_freq = MAX_FREQ;
>> > >> + min_freq = MIN_FREQ;
>> > >> + }
>> > >> +
>> > >> + pm_runtime_enable(&pdev->dev);
>> > >> + pm_runtime_irq_safe(&pdev->dev);
>> > >> +
>> > >> + /*
>> > >> + * check if the efuse has a non-zero value if not
>> > >> + * it is an untrimmed sample and the temperatures
>> > >> + * may not be accurate
>> > >> + */
>> > >> +
>> > >> + if (omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_efuse)) {
>> > >> + temp_sensor->is_efuse_valid = 1;
>> > >
>> > > is_efuse_valid is not used anywhere. Might as well drop it.
>> >
>> > Ok
>> >
>> > >
>> > >> + dev_dbg(temp_sensor->hwmon_dev,
>> > >> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
>> > >
>> > > dev_info might be better here.
>> >
>> > Ok.
>> >
>> > >
>> > >> + }
>> > >> +
>> > >> + dev_set_drvdata(&pdev->dev, temp_sensor);
>> > >> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
>> > >> + if (IS_ERR(temp_sensor->clock)) {
>> > >> + ret = PTR_ERR(temp_sensor->clock);
>> > >> + dev_err(temp_sensor->hwmon_dev,
>> > >> + "unable to get fclk: %d\n", ret);
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >> + ret = omap_temp_sensor_clk_enable(temp_sensor);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
>> > >
>> > > omap_temp_sensor_clk_enable() already generates error messages.
>> >
>> > Ok. I will remove this.
>> >
>> > >
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
>> > >> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
>> > >> + dev_err(&pdev->dev, "Error round rate\n");
>> > >> + ret = -EDOM;
>> > >
>> > > EDOM is wrong. Please use ENODEV.
>> >
>> > Ok
>> >
>> > >
>> > > The error log doesn't really provide anything useful to the administrator.
>> > > Either add parameters, or drop it.
>> >
>> > Ok
>> >
>> > >
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Cannot set clock rate\n");
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + temp_sensor->clk_rate = clk_rate;
>> > >> + omap_enable_continuous_mode(temp_sensor, 1);
>> > >> + omap_configure_temp_sensor_thresholds(temp_sensor);
>> > >> + /* 1 ms */
>> > >> + omap_configure_temp_sensor_counter(temp_sensor, 1);
>> > >
>> > > If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
>> > > 1ms would be temp_sensor->clk_rate / 1000.
>> >
>> > Yes! Wrong comment. It is configured to start the temperature conversion.
>> > It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
>> >
>> > >
>> > >> +
>> > >> + /* Wait till the first conversion is done wait for at least 1ms */
>> > >> + usleep_range(1000, 2000);
>> > >> +
>> > >> + /* Read the temperature once due to hw issue*/
>> > >> + omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->temp_sensor_ctrl);
>> > >> +
>> > >> + /* Set 2 seconds time as default counter */
>> > >> + omap_configure_temp_sensor_counter(temp_sensor,
>> > >> + temp_sensor->clk_rate * 2);
>> > >> +
>> > >> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
>> > >> + if (IS_ERR(temp_sensor->hwmon_dev)) {
>> > >> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
>> > >> + ret = PTR_ERR(temp_sensor->hwmon_dev);
>> > >> + goto hwmon_reg_err;
>> > >> + }
>> > >> +
>> > >> + ret = sysfs_create_group(&pdev->dev.kobj,
>> > >> + &omap_temp_sensor_group);
>> > >
>> > > one line is sufficient here.
>> >
>> > Ok.
>> >
>> > >
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> > >> + goto sysfs_create_err;
>> > >> + }
>> > >> +
>> > >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
>> > >> +
>> > >
>> > > No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
>> >
>> > Yes i will remove this.
>> >
>> > >
>> > >> + ret = request_threaded_irq(temp_sensor->irq, NULL,
>> > >> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> > >> + "temp_sensor", temp_sensor);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
>> > >> + goto req_irq_err;
>> > >> + }
>> > >> +
>> > >> + /* unmask the T_COLD and unmask T_HOT at init */
>> > >> + val = omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_mask_ctrl);
>> > >> + val |= temp_sensor->registers->mask_cold_mask
>> > >> + | temp_sensor->registers->mask_hot_mask;
>> > >> +
>> > >> + omap_temp_sensor_writel(temp_sensor, val,
>> > >> + temp_sensor->registers->bgap_mask_ctrl);
>> > >> +
>> > > This is racy. From Documentation/hwmon/submitting-patches:
>> >
>> > I read it. If i enable the interrupts before i have the sysfs
>> > infrastructure ready.
>> > I am likely to miss out on the uevent notification if the interrupt
>> > occurs as soon as
>> > i unmask. Correct me if my understanding is wrong.
>> >
>> See other email on sequence subject. I'll have to look into it in more detail.
>> later - no time right now ...
>
> Concerns:
>
> - create sysfs entries first, then register with hwmon.
> hwmon_device_register is usually the last call, made only after
> everything is known to work.
> - You can definitely request the interrupt before registering sysfs
> entries
> - temp_sensor->hwmon_dev is initially set to
> temp_sensor->hwmon_dev = &pdev->dev;
> then overwritten with
> temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> This is, at the very least, odd and doesn't seem to make sense.
> - Interrupt enable code (setting bgap_mask_ctrl) in probe function
> occurs after sysfs files have been enabled, and the access is not mutex
> protected. Thus, sysfs access can already happen, causing the main race
> I was concerned about.
>
> My suggestion is
> - request interrupt prior to sysfs creation and hwmon registration.
> - swap sysfs file creation and hwmon registration.
> - Use the unified function I suggested above to set t_cold, t_hot, and
> to enable interrupts as needed. Since that function will be mutex
> protected, you can call it after hwmon registration, and avoid the race.
>
> Also look into use of temp_sensor->hwmon_dev vs. &pdev->dev. That code
> just doesn't look right.
Thanks for the inputs. I will work on them and get back.
>
> Thanks,
> Guenter
>
>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 15:56 ` [lm-sensors] " Guenter Roeck
2011-08-25 16:06 ` J, KEERTHY
@ 2011-08-26 11:17 ` J, KEERTHY
2011-08-26 16:16 ` Guenter Roeck
1 sibling, 1 reply; 19+ messages in thread
From: J, KEERTHY @ 2011-08-26 11:17 UTC (permalink / raw)
To: guenter.roeck; +Cc: linux-omap@vger.kernel.org, lm-sensors@lm-sensors.org
On Thu, Aug 25, 2011 at 9:26 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Thu, 2011-08-25 at 10:06 -0400, Guenter Roeck wrote:
>> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
>> > On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
>> > <guenter.roeck@ericsson.com> wrote:
>> > > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> > >> On chip temperature sensor driver. The driver monitors the temperature of
>> > >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> > >> the temperature crosses user defined thresholds via kobject_uevent interface.
>> > >> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> > >> exposed using hwmon interface.
>> > >>
>> > >> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> > >> Cc: Jean Delvare <khali@linux-fr.org>
>> > >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> > >> Cc: lm-sensors@lm-sensors.org
>> > >
>
> [ ... ]
>
>
>> >
>> > >
>> > >> + }
>> > >> +
>> > >> + mutex_lock(&temp_sensor->sensor_mutex);
>> > >> + /* obtain the T cold value */
>> > >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_threshold);
>> > >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> > >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> > >> +
>> > >> + if (t_hot < t_cold) {
>> > >> + count = -EINVAL;
>> > >> + goto out;
>> > >
>> > > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
>> > > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
>> > > change order order well defined or even possible. Applications should not have to bother about this.
>> >
>> > The hardware behavior is like this. As long as the temperature is below
>> > t_hot no interrupts are fired. Once the temperature increases above
>> > t_hot we get an
>> > interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
>> > in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
>> > interrupt only when the temperature drops below the t_cold value. Hence
>> > setting the t_cold higher than t_hot will mess up the state machine.
>> >
>> > t_hot value should be greater than t_cold value.
>> >
>> One option would be to update t_cold (max_hyst) automatically in that case.
>>
>> Problem here is that you expect the application to know, depending on the current
>> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
>> expectation.
>>
> One possible solution would be to have a single function to set both
> t_cold and t_hot, and call it from both initialization code and from the
> set functions. That would unify all the register setting and interrupt
> enable code.
>
> Regarding the actual values to set, you can (as an example) use the
> following approach:
>
> - If max is set, and t_hot < t_cold, adjust t_cold to the new value of
> t_hot.
>
> - if max_hyst is set, and t_cold > t_hot, set t_cold to the new value of
> t_hot.
>
> So, in other words, your new unified function would only need the
> following simple validation:
>
> if (t_cold > t_hot)
> t_cold = t_hot;
One concern here. There should be a hysteresis
difference between the two and can not be equal.
I need to add a hysteresis value to t_hot so as
to maintain t_hot > t_cold condition.
>
> [ ... ]
>
>> > >> +
>> > >> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
>> > >> +{
>> > >> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
>> > >> + struct omap_temp_sensor *temp_sensor;
>> > >> + struct resource *mem;
>> > >> + int ret = 0;
>> > >> + int val, clk_rate;
>> > >> + u32 max_freq, min_freq;
>> > >> +
>> > >> + if (!pdata) {
>> > >> + dev_err(&pdev->dev, "platform data missing\n");
>> > >> + return -EINVAL;
>> > >> + }
>> > >> +
>> > >> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
>> > >> + if (!temp_sensor)
>> > >> + return -ENOMEM;
>> > >> +
>> > >
>> > > You have error messages all over the place, Why not here ?
>> >
>> > Ok. I will add an error message here.
>> >
>> > >
>> > >> + mutex_init(&temp_sensor->sensor_mutex);
>> > >> +
>> > >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> > >> + if (!mem) {
>> > >> + dev_err(&pdev->dev, "no mem resource\n");
>> > >> + ret = -ENOMEM;
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >
>> > > If you try to get the resource before allocating the memory, you don't have to release
>> > > the memory if the platform resource is missing.
>> >
>> > Ok. Here if i fail i am releasing temp_sensor memory which
>> > has been allocated.
>> >
>> > >
>> > >> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
>> > >> + if (temp_sensor->irq < 0) {
>> > >> + dev_err(&pdev->dev, "get_irq_byname failed\n");
>> > >> + ret = temp_sensor->irq;
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>> > >> + temp_sensor->clock = NULL;
>> > >> + temp_sensor->registers = pdata->registers;
>> > >> + temp_sensor->hwmon_dev = &pdev->dev;
>> > >> +
>> > >> + if (pdata->max_freq && pdata->min_freq) {
>> > >> + max_freq = pdata->max_freq;
>> > >> + min_freq = pdata->min_freq;
>> > >> + } else {
>> > >> + max_freq = MAX_FREQ;
>> > >> + min_freq = MIN_FREQ;
>> > >> + }
>> > >> +
>> > >> + pm_runtime_enable(&pdev->dev);
>> > >> + pm_runtime_irq_safe(&pdev->dev);
>> > >> +
>> > >> + /*
>> > >> + * check if the efuse has a non-zero value if not
>> > >> + * it is an untrimmed sample and the temperatures
>> > >> + * may not be accurate
>> > >> + */
>> > >> +
>> > >> + if (omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_efuse)) {
>> > >> + temp_sensor->is_efuse_valid = 1;
>> > >
>> > > is_efuse_valid is not used anywhere. Might as well drop it.
>> >
>> > Ok
>> >
>> > >
>> > >> + dev_dbg(temp_sensor->hwmon_dev,
>> > >> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
>> > >
>> > > dev_info might be better here.
>> >
>> > Ok.
>> >
>> > >
>> > >> + }
>> > >> +
>> > >> + dev_set_drvdata(&pdev->dev, temp_sensor);
>> > >> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
>> > >> + if (IS_ERR(temp_sensor->clock)) {
>> > >> + ret = PTR_ERR(temp_sensor->clock);
>> > >> + dev_err(temp_sensor->hwmon_dev,
>> > >> + "unable to get fclk: %d\n", ret);
>> > >> + goto plat_res_err;
>> > >> + }
>> > >> +
>> > >> + ret = omap_temp_sensor_clk_enable(temp_sensor);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
>> > >
>> > > omap_temp_sensor_clk_enable() already generates error messages.
>> >
>> > Ok. I will remove this.
>> >
>> > >
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
>> > >> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
>> > >> + dev_err(&pdev->dev, "Error round rate\n");
>> > >> + ret = -EDOM;
>> > >
>> > > EDOM is wrong. Please use ENODEV.
>> >
>> > Ok
>> >
>> > >
>> > > The error log doesn't really provide anything useful to the administrator.
>> > > Either add parameters, or drop it.
>> >
>> > Ok
>> >
>> > >
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Cannot set clock rate\n");
>> > >> + goto clken_err;
>> > >> + }
>> > >> +
>> > >> + temp_sensor->clk_rate = clk_rate;
>> > >> + omap_enable_continuous_mode(temp_sensor, 1);
>> > >> + omap_configure_temp_sensor_thresholds(temp_sensor);
>> > >> + /* 1 ms */
>> > >> + omap_configure_temp_sensor_counter(temp_sensor, 1);
>> > >
>> > > If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
>> > > 1ms would be temp_sensor->clk_rate / 1000.
>> >
>> > Yes! Wrong comment. It is configured to start the temperature conversion.
>> > It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
>> >
>> > >
>> > >> +
>> > >> + /* Wait till the first conversion is done wait for at least 1ms */
>> > >> + usleep_range(1000, 2000);
>> > >> +
>> > >> + /* Read the temperature once due to hw issue*/
>> > >> + omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->temp_sensor_ctrl);
>> > >> +
>> > >> + /* Set 2 seconds time as default counter */
>> > >> + omap_configure_temp_sensor_counter(temp_sensor,
>> > >> + temp_sensor->clk_rate * 2);
>> > >> +
>> > >> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
>> > >> + if (IS_ERR(temp_sensor->hwmon_dev)) {
>> > >> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
>> > >> + ret = PTR_ERR(temp_sensor->hwmon_dev);
>> > >> + goto hwmon_reg_err;
>> > >> + }
>> > >> +
>> > >> + ret = sysfs_create_group(&pdev->dev.kobj,
>> > >> + &omap_temp_sensor_group);
>> > >
>> > > one line is sufficient here.
>> >
>> > Ok.
>> >
>> > >
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> > >> + goto sysfs_create_err;
>> > >> + }
>> > >> +
>> > >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
>> > >> +
>> > >
>> > > No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
>> >
>> > Yes i will remove this.
>> >
>> > >
>> > >> + ret = request_threaded_irq(temp_sensor->irq, NULL,
>> > >> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> > >> + "temp_sensor", temp_sensor);
>> > >> + if (ret) {
>> > >> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
>> > >> + goto req_irq_err;
>> > >> + }
>> > >> +
>> > >> + /* unmask the T_COLD and unmask T_HOT at init */
>> > >> + val = omap_temp_sensor_readl(temp_sensor,
>> > >> + temp_sensor->registers->bgap_mask_ctrl);
>> > >> + val |= temp_sensor->registers->mask_cold_mask
>> > >> + | temp_sensor->registers->mask_hot_mask;
>> > >> +
>> > >> + omap_temp_sensor_writel(temp_sensor, val,
>> > >> + temp_sensor->registers->bgap_mask_ctrl);
>> > >> +
>> > > This is racy. From Documentation/hwmon/submitting-patches:
>> >
>> > I read it. If i enable the interrupts before i have the sysfs
>> > infrastructure ready.
>> > I am likely to miss out on the uevent notification if the interrupt
>> > occurs as soon as
>> > i unmask. Correct me if my understanding is wrong.
>> >
>> See other email on sequence subject. I'll have to look into it in more detail.
>> later - no time right now ...
>
> Concerns:
>
> - create sysfs entries first, then register with hwmon.
> hwmon_device_register is usually the last call, made only after
> everything is known to work.
> - You can definitely request the interrupt before registering sysfs
> entries
> - temp_sensor->hwmon_dev is initially set to
> temp_sensor->hwmon_dev = &pdev->dev;
> then overwritten with
> temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> This is, at the very least, odd and doesn't seem to make sense.
> - Interrupt enable code (setting bgap_mask_ctrl) in probe function
> occurs after sysfs files have been enabled, and the access is not mutex
> protected. Thus, sysfs access can already happen, causing the main race
> I was concerned about.
>
> My suggestion is
> - request interrupt prior to sysfs creation and hwmon registration.
> - swap sysfs file creation and hwmon registration.
> - Use the unified function I suggested above to set t_cold, t_hot, and
> to enable interrupts as needed. Since that function will be mutex
> protected, you can call it after hwmon registration, and avoid the race.
>
> Also look into use of temp_sensor->hwmon_dev vs. &pdev->dev. That code
> just doesn't look right.
>
> Thanks,
> Guenter
>
>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-26 11:17 ` J, KEERTHY
@ 2011-08-26 16:16 ` Guenter Roeck
2011-08-27 16:37 ` J, KEERTHY
0 siblings, 1 reply; 19+ messages in thread
From: Guenter Roeck @ 2011-08-26 16:16 UTC (permalink / raw)
To: J, KEERTHY; +Cc: linux-omap@vger.kernel.org, lm-sensors@lm-sensors.org
On Fri, 2011-08-26 at 07:17 -0400, J, KEERTHY wrote:
> On Thu, Aug 25, 2011 at 9:26 PM, Guenter Roeck
> <guenter.roeck@ericsson.com> wrote:
> > On Thu, 2011-08-25 at 10:06 -0400, Guenter Roeck wrote:
> >> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
> >> > On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
> >> > <guenter.roeck@ericsson.com> wrote:
> >> > > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> >> > >> On chip temperature sensor driver. The driver monitors the temperature of
> >> > >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> >> > >> the temperature crosses user defined thresholds via kobject_uevent interface.
> >> > >> The user is allowed to configure the temperature thresholds vis sysfs nodes
> >> > >> exposed using hwmon interface.
> >> > >>
> >> > >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> >> > >> Cc: Jean Delvare <khali@linux-fr.org>
> >> > >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> >> > >> Cc: lm-sensors@lm-sensors.org
> >> > >
> >
> > [ ... ]
> >
> >
> >> >
> >> > >
> >> > >> + }
> >> > >> +
> >> > >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> > >> + /* obtain the T cold value */
> >> > >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> >> > >> + temp_sensor->registers->bgap_threshold);
> >> > >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> >> > >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> > >> +
> >> > >> + if (t_hot < t_cold) {
> >> > >> + count = -EINVAL;
> >> > >> + goto out;
> >> > >
> >> > > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> >> > > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> >> > > change order order well defined or even possible. Applications should not have to bother about this.
> >> >
> >> > The hardware behavior is like this. As long as the temperature is below
> >> > t_hot no interrupts are fired. Once the temperature increases above
> >> > t_hot we get an
> >> > interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
> >> > in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
> >> > interrupt only when the temperature drops below the t_cold value. Hence
> >> > setting the t_cold higher than t_hot will mess up the state machine.
> >> >
> >> > t_hot value should be greater than t_cold value.
> >> >
> >> One option would be to update t_cold (max_hyst) automatically in that case.
> >>
> >> Problem here is that you expect the application to know, depending on the current
> >> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
> >> expectation.
> >>
> > One possible solution would be to have a single function to set both
> > t_cold and t_hot, and call it from both initialization code and from the
> > set functions. That would unify all the register setting and interrupt
> > enable code.
> >
> > Regarding the actual values to set, you can (as an example) use the
> > following approach:
> >
> > - If max is set, and t_hot < t_cold, adjust t_cold to the new value of
> > t_hot.
> >
> > - if max_hyst is set, and t_cold > t_hot, set t_cold to the new value of
> > t_hot.
> >
> > So, in other words, your new unified function would only need the
> > following simple validation:
> >
> > if (t_cold > t_hot)
> > t_cold = t_hot;
>
> One concern here. There should be a hysteresis
> difference between the two and can not be equal.
> I need to add a hysteresis value to t_hot so as
> to maintain t_hot > t_cold condition.
>
Sure, makes sense. Was that in your original patch ? Just wondering.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-26 16:16 ` Guenter Roeck
@ 2011-08-27 16:37 ` J, KEERTHY
0 siblings, 0 replies; 19+ messages in thread
From: J, KEERTHY @ 2011-08-27 16:37 UTC (permalink / raw)
To: guenter.roeck; +Cc: linux-omap@vger.kernel.org, lm-sensors@lm-sensors.org
On Fri, Aug 26, 2011 at 9:46 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Fri, 2011-08-26 at 07:17 -0400, J, KEERTHY wrote:
>> On Thu, Aug 25, 2011 at 9:26 PM, Guenter Roeck
>> <guenter.roeck@ericsson.com> wrote:
>> > On Thu, 2011-08-25 at 10:06 -0400, Guenter Roeck wrote:
>> >> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
>> >> > On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
>> >> > <guenter.roeck@ericsson.com> wrote:
>> >> > > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> >> > >> On chip temperature sensor driver. The driver monitors the temperature of
>> >> > >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> >> > >> the temperature crosses user defined thresholds via kobject_uevent interface.
>> >> > >> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> >> > >> exposed using hwmon interface.
>> >> > >>
>> >> > >> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> >> > >> Cc: Jean Delvare <khali@linux-fr.org>
>> >> > >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> >> > >> Cc: lm-sensors@lm-sensors.org
>> >> > >
>> >
>> > [ ... ]
>> >
>> >
>> >> >
>> >> > >
>> >> > >> + }
>> >> > >> +
>> >> > >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> > >> + /* obtain the T cold value */
>> >> > >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> >> > >> + temp_sensor->registers->bgap_threshold);
>> >> > >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> >> > >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> >> > >> +
>> >> > >> + if (t_hot < t_cold) {
>> >> > >> + count = -EINVAL;
>> >> > >> + goto out;
>> >> > >
>> >> > > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
>> >> > > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
>> >> > > change order order well defined or even possible. Applications should not have to bother about this.
>> >> >
>> >> > The hardware behavior is like this. As long as the temperature is below
>> >> > t_hot no interrupts are fired. Once the temperature increases above
>> >> > t_hot we get an
>> >> > interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
>> >> > in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
>> >> > interrupt only when the temperature drops below the t_cold value. Hence
>> >> > setting the t_cold higher than t_hot will mess up the state machine.
>> >> >
>> >> > t_hot value should be greater than t_cold value.
>> >> >
>> >> One option would be to update t_cold (max_hyst) automatically in that case.
>> >>
>> >> Problem here is that you expect the application to know, depending on the current
>> >> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
>> >> expectation.
>> >>
>> > One possible solution would be to have a single function to set both
>> > t_cold and t_hot, and call it from both initialization code and from the
>> > set functions. That would unify all the register setting and interrupt
>> > enable code.
>> >
>> > Regarding the actual values to set, you can (as an example) use the
>> > following approach:
>> >
>> > - If max is set, and t_hot < t_cold, adjust t_cold to the new value of
>> > t_hot.
>> >
>> > - if max_hyst is set, and t_cold > t_hot, set t_cold to the new value of
>> > t_hot.
>> >
>> > So, in other words, your new unified function would only need the
>> > following simple validation:
>> >
>> > if (t_cold > t_hot)
>> > t_cold = t_hot;
>>
>> One concern here. There should be a hysteresis
>> difference between the two and can not be equal.
>> I need to add a hysteresis value to t_hot so as
>> to maintain t_hot > t_cold condition.
>>
> Sure, makes sense. Was that in your original patch ? Just wondering.
Original patch never let the user set thresholds which failed to
satisfy the condition t_hot > t_cold. The original patch threw up
error if this condition was violated.
>
> Thanks,
> Guenter
>
>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 14:06 ` Guenter Roeck
2011-08-25 15:56 ` [lm-sensors] " Guenter Roeck
@ 2011-08-25 16:04 ` J, KEERTHY
2011-08-25 16:19 ` Guenter Roeck
1 sibling, 1 reply; 19+ messages in thread
From: J, KEERTHY @ 2011-08-25 16:04 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, Aug 25, 2011 at 7:36 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
>> On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
>> <guenter.roeck@ericsson.com> wrote:
>> > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> >> On chip temperature sensor driver. The driver monitors the temperature of
>> >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> >> the temperature crosses user defined thresholds via kobject_uevent interface.
>> >> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> >> exposed using hwmon interface.
>> >>
>> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> >> Cc: Jean Delvare <khali@linux-fr.org>
>> >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> >> Cc: lm-sensors@lm-sensors.org
>> >
>> > Partial review only. Too many concerns, and after a while I tend to loose track.
>> >
>> >> ---
>> >> Documentation/hwmon/omap_temp_sensor | 27 +
>> >> drivers/hwmon/Kconfig | 11 +
>> >> drivers/hwmon/Makefile | 1 +
>> >> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
>> >> 4 files changed, 972 insertions(+), 0 deletions(-)
>> >> create mode 100644 Documentation/hwmon/omap_temp_sensor
>> >> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>> >>
>
> [ ... ]
>
>> >> +/* Sysfs hook functions */
>> >> +
>> >> +static ssize_t show_temp_max(struct device *dev,
>> >> + struct device_attribute *devattr, char *buf)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + int temp;
>> >> +
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
>> >> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
>> >> +
>> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> >> + dev_err(dev, "invalid value\n");
>> >> + return -EDOM;
>> >
>> > Please don't use EDOM, and drop the error message.
>>
>> The temperature is out of range. Should i use EIO?
>>
> It is out of range, but not due to a math error, but due to a bad reading from the chip
> or due to a chip failure. EIO is ok.
Ok
>
>> >
>> >> + }
>> >> +
>> >> + temp = adc_to_temp_conversion(temp);
>> >> +
>> >> + return snprintf(buf, 16, "%d\n", temp);
>> >> +}
>> >> +
>> >> +static ssize_t set_temp_max(struct device *dev,
>> >> + struct device_attribute *devattr,
>> >> + const char *buf, size_t count)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + long val;
>> >> + u32 reg_val, t_cold, t_hot, temp;
>> >> +
>> >> + if (strict_strtol(buf, 10, &val)) {
>> >> + count = -EINVAL;
>> >> + goto out;
>> >
>> > This will try to release the not-acquired lock.
>>
>> I will correct this.
>>
>> >
>> >> + }
>> >> +
>> >> + t_hot = temp_to_adc_conversion(val);
>> >
>> > Bad error return check. Negative on error. Should be
>> > if (t_hot < 0)
>> > return t_hot;
>>
>> Ok.
>>
>> >
>> >> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
>> >
>> > Unnecessary (( ))
>>
>> This check is unnecessary with the negative check. I will remove.
>>
>> >
>> >> + count = -EINVAL;
>> >> + goto out;
>> >
>> > This will try to release the not-acquired lock.
>>
>> I will correct this.
>>
>> >
>> >> + }
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> + /* obtain the T cold value */
>> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> >> +
>> >> + if (t_hot < t_cold) {
>> >> + count = -EINVAL;
>> >> + goto out;
>> >
>> > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
>> > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
>> > change order order well defined or even possible. Applications should not have to bother about this.
>>
>> The hardware behavior is like this. As long as the temperature is below
>> t_hot no interrupts are fired. Once the temperature increases above
>> t_hot we get an
>> interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
>> in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
>> interrupt only when the temperature drops below the t_cold value. Hence
>> setting the t_cold higher than t_hot will mess up the state machine.
>>
>> t_hot value should be greater than t_cold value.
>>
> One option would be to update t_cold (max_hyst) automatically in that case.
updating the t_cold without application's knowledge?
>
> Problem here is that you expect the aplication to know, depending on the current
> values of (max, max_hyst), how to update both limits in order. That is not a reasonable
> expectation.
The thermal application which is configuring the thresholds must be
intelligent enough to configure the thresholds in the right order. Configuring
the thresholds wrongly and missing the interrupt may even result in burning
the chip.
>
>> >
>> >> + }
>> >> +
>> >> + /* write the new t_hot value */
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
>> >> + reg_val |= (t_hot <<
>> >> + __ffs(temp_sensor->registers->threshold_thot_mask));
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> +
>> >> + /* Read the current temperature */
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->temp_sensor_ctrl);
>> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> >> +
>> >> + /*
>> >> + * If user sets the HIGH threshold(t_hot) greater than the current
>> >> + * temperature(temp) unmask the HOT interrupts
>> >> + */
>> >> + if (t_hot > temp) {
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
>> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + }
>> >> +
>> >> + /*
>> >> + * If current temperature is in-between the hot and cold thresholds,
>> >> + * Enable both masks.
>> >> + */
>> >> + if (temp > t_cold && temp < t_hot) {
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + OMAP4460_BGAP_CTRL_OFFSET);
>> >
>> > Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
>>
>> Ok. I will change this.
>>
>> >
>> >> + }
>> >> + /*
>> >> + * else no need to do anything since HW will immediately compare
>> >> + * the new threshold and generate interrupt accordingly
>> >> + */
>> >> +out:
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >> + return count;
>> >> +}
>> >> +
>> >> +static ssize_t show_temp_max_hyst(struct device *dev,
>> >> + struct device_attribute *devattr, char *buf)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + u32 temp;
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >
>> > This lock would only make sense if threshold_tcold_mask can change, and if that change
>> > would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
>> > Besides, the code in show_temp_max() is almost the same and does not use the lock.
>>
>> The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
>> ISR function. It is better to protect with mutex. I will add that in
>> required places.
>>
> Reeally ? I seem to be blind. I searched for threshold_tcold_mask in the patch but
> did not see where it is changed. Can you point me to the code ?
I misread it. Yes threshold_tcold_mask is used only in show_temp_max_hyst(),
set_temp_max(), set_temp_max_hyst() functions. It is set only in the
set_temp_max_hyst()
function.
>
> If it is changed outside the driver, you have a real problem, since there is no guarantee
> that the mask is not changed from outside the driver, by code not protected by the mutex.
> And if read functions have the side effect of changing such values, there should really
> be a note somewhere to make people aware of it. I'd call that side effect programming,
> and would argue it is a really bad idea.
It is not changed anywhere outside the driver.
>
>> >
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
>> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> >> + dev_err(dev, "invalid value\n");
>> >> + return -EDOM;
>> >
>> > "Math argument out of domain of func" does not make sense.
>> > Unless you don't know anything better, use EIO (I/O Error). Not very specific,
>> > but at least not misleading.
>>
>> Out of range i assumed this was the closest error value. I will use EIO.
>>
> It is not a math error, though.
Ok
>
>> >
>> > Besides, the log message is unnecessary. The user is informed with -EIO, and the admin
>> > won't be able to do anything useful with "invalid value".
>>
>> Ok. I will return -EIO and eliminate the log message.
>>
>> >
>> >> + }
>> >> +
>> >> + temp = adc_to_temp_conversion(temp);
>> >> +
>> >> + return snprintf(buf, 16, "%d\n", temp);
>> >> +}
>> >> +
>> >> +static ssize_t set_temp_max_hyst(struct device *dev,
>> >> + struct device_attribute *devattr,
>> >> + const char *buf, size_t count)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + u32 reg_val, t_hot, t_cold, temp;
>> >> + long val;
>> >> +
>> >> + if (strict_strtol(buf, 10, &val)) {
>> >> + count = -EINVAL;
>> >> + goto out;
>> >
>> > This will try to release the not acquired lock.
>>
>> I will correct this.
>>
>> >
>> >> + }
>> >> +
>> >> + t_cold = temp_to_adc_conversion(val);
>> >
>> > Bad error return check; same as above.
>>
>> Ok. I will correct this.
>>
>> >
>> >> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
>> >> + count = -EINVAL;
>> >> + goto out;
>> >> + }
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> + /* obtain the T HOT value */
>> >> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
>> >> + __ffs(temp_sensor->registers->threshold_thot_mask);
>> >> +
>> >> + if (t_cold > t_hot) {
>> >
>> > Same concern as above. Change order is left to application which should not be bothered.
>> >
>> >> + count = -EINVAL;
>> >> + goto out;
>> >> + }
>> >> +
>> >> + /* write the new t_cold value */
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
>> >> + reg_val |= t_cold <<
>> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_threshold);
>> >> +
>> >> + /* Read the current temperature */
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->temp_sensor_ctrl);
>> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> >> +
>> >> + /*
>> >> + * If user sets the LOW threshold(t_cold) lower than the current
>> >> + * temperature(temp) unmask the COLD interrupts
>> >> + */
>> >> + if (t_cold < temp) {
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
>> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + }
>> >> +
>> >> + /*
>> >> + * If current temperature is in-between the hot and cold thresholds,
>> >> + * Enable both masks.
>> >> + */
>> >> + if (temp < t_hot && temp > t_cold) {
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + }
>> >> +
>> >> + /*
>> >> + * else no need to do anything since HW will immediately compare
>> >> + * the new threshold and generate interrupt accordingly
>> >> + */
>> >
>> > Would be nice if you could unify the interrupt enable code in a single function.
>>
>> Ok. I will have a function for this.
>>
>> >
>> >> +
>> >> +out:
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >> + return count;
>> >> +}
>> >> +
>> >> +static ssize_t show_update_rate(struct device *dev,
>> >> + struct device_attribute *devattr, char *buf)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + u32 temp = 0, ret = 0;
>> >> +
>> > No need to initialize temp.
>> > ret is u32, which doesn't seem to be a good type to use for negative values.
>>
>> Oops yes. I will correct this.
>>
>> >
>> >> +
>> >> + if (!temp_sensor->clk_rate) {
>> >> + dev_err(dev, "clk_rate is NULL\n");
>> >> + ret = -EDOM;
>> >
>> > Same comment as above (this is not a math error). And you don't have to check clk_rate anyway,
>> > since it is set in probe, and probe bails out if it is not set.
>>
>> Ok
>>
>> >
>> >> + goto out;
>> >> + }
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >
>> > As with other show locks, this one would only make sense if counter_mask can change during runtime,
>> > and if that change would be protected by the mutex. This is not the case, thus the lock is unnecessary.
>>
>> Counter value can be altered runtime. A lock is needed in both the cases.
>> I will add it.
>>
> clk_rate does not change, counter_mask does not change, and reading a single value
> doesn't need a mutex. Am I missing something ?
Ok. I will remove the lock from show function.
>
>> >
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_counter);
>> >> + temp = (temp & temp_sensor->registers->counter_mask) >>
>> >> + __ffs(temp_sensor->registers->counter_mask);
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> + temp = temp * 1000 / temp_sensor->clk_rate;
>> >> +
>> >> +out:
>> >> + if (!ret)
>> >> + return sprintf(buf, "%d\n", temp);
>> >> +
>> >> + return ret;
>> >> +}
>> >> +
>> >> +static ssize_t set_update_rate(struct device *dev,
>> >> + struct device_attribute *devattr,
>> >> + const char *buf, size_t count)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + u32 reg_val;
>> >> + long val;
>> >> +
>> >> + if (strict_strtol(buf, 10, &val)) {
>> >> + count = -EINVAL;
>> >> + goto out;
>> >> + }
>> >> +
>> >> + val *= temp_sensor->clk_rate / 1000;
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_counter);
>> >> +
>> >> + reg_val &= ~temp_sensor->registers->counter_mask;
>> >> + reg_val |= val;
>> >
>> > Sure you want to accept any value (including negative ones) here ?
>> > val is not shifted, and not masked against counter_mask, meaning it can write
>> > all bits of the register. That doesn't sound right.
>>
>> I will have a check.
>>
>> >
>> > It would make sense to call omap_configure_temp_sensor_counter() instead of duplicating
>> > the set functionality.
>>
>> Yes I will make use of that.
>>
>> >
>> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> + temp_sensor->registers->bgap_counter);
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >> +out:
>> >> + return count;
>> >> +}
>> >> +
>> >> +static int omap_temp_sensor_read_temp(struct device *dev,
>> >> + struct device_attribute *devattr,
>> >> + char *buf)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> + int temp, ret = 0;
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >
>> > Unless bgap_dtemp_mask can change during runtime, and that change is protected by the mutex,
>> > this lock is unnecessary.
>>
>> It is read only and is updated by hardware. Change cannot be protected by mutex.
>>
>> >
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->temp_sensor_ctrl);
>> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> >> +
>> >> + /* look up for temperature in the table and return the temperature */
>> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> >> + dev_err(dev, "invalid adc code reported %d", temp);
>> >> + ret = -EDOM;
>> >
>> > Another wrong use of EDOM, and another value-free error message.
>>
>> Ok. I will use -EIO and drop the error message.
>>
>> >
>> >> + goto out;
>> >> + }
>> >> +
>> >> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
>> >> +
>> >> +out:
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> + if (!ret)
>> >> + return sprintf(buf, "%d\n", temp);
>> >> +
>> >> + return ret;
>> >> +}
>> >> +
>> >> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, omap_temp_sensor_read_temp,
>> >> + NULL, 0);
>> >> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
>> >> + set_temp_max, 0);
>> >> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_max_hyst,
>> >> + set_temp_max_hyst, 0);
>> >> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO, show_update_rate,
>> >> + set_update_rate, 0);
>> >> +
>> >
>> > ABI is update_interval. Please use it.
>>
>> Ok.
>>
>> >
>> >> +static struct attribute *omap_temp_sensor_attributes[] = {
>> >> + &sensor_dev_attr_temp1_input.dev_attr.attr,
>> >> + &sensor_dev_attr_temp1_max.dev_attr.attr,
>> >> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
>> >> + &sensor_dev_attr_update_rate.dev_attr.attr,
>> >> + NULL
>> >> +};
>> >> +
>> >> +static const struct attribute_group omap_temp_sensor_group = {
>> >> + .attrs = omap_temp_sensor_attributes,
>> >> +};
>> >> +
>> >> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor *temp_sensor)
>> >> +{
>> >> + u32 ret = 0;
>> >> +
>> >> + if (temp_sensor->clk_on) {
>> >> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
>> >> + goto out;
>> >> + }
>> >> +
>> >> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
>> >> + if (ret < 0) {
>> >> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
>> >> + goto out;
>> >> + }
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> + temp_sensor->clk_on = 1;
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >
>> > Completely unnecessary lock.
>>
>> Ok
>>
>> >
>> >> +out:
>> >> + return ret;
>> >> +}
>> >> +
>> >> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
>> >
>> > Return code is not used anywhere, why bother providing one ?
>>
>> It is not checked in the error path. I can make it void.
>>
>> >
>> >> +{
>> >> + u32 ret = 0;
>> >> +
>> >> + if (!temp_sensor->clk_on) {
>> >> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
>> >> + goto out;
>> >
>> > ... and since you ignore the error anyway, why log it ?
>>
>> Ok. I will remove the log message.
>>
>> >
>> >> + }
>> >> +
>> >> + /* Gate the clock */
>> >> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
>> >> + if (ret < 0) {
>> >> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
>> >> + goto out;
>> >> + }
>> >> +
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> + temp_sensor->clk_on = 0;
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >
>> > Completely unnecessary lock.
>>
>> Ok
>>
>> >
>> >> +out:
>> >> + return ret;
>> >> +}
>> >> +
>> >> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
>> >> +{
>> >> + struct omap_temp_sensor *temp_sensor;
>> >> + int t_hot, t_cold, temp;
>> >> +
>> >> + temp_sensor = data;
>> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> +
>> >> + /* Read the status of t_hot */
>> >> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_status)
>> >> + & temp_sensor->registers->status_hot_mask;
>> >> +
>> >> + /* Read the status of t_cold */
>> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_status)
>> >> + & temp_sensor->registers->status_cold_mask;
>> >> +
>> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + /*
>> >> + * One TALERT interrupt: Two sources
>> >> + * If the interrupt is due to t_hot then mask t_hot and
>> >> + * and unmask t_cold else mask t_cold and unmask t_hot
>> >> + */
>> >> + if (t_hot) {
>> >> + temp &= ~temp_sensor->registers->mask_hot_mask;
>> >> + temp |= temp_sensor->registers->mask_cold_mask;
>> >> + } else if (t_cold) {
>> >> + temp &= ~temp_sensor->registers->mask_cold_mask;
>> >> + temp |= temp_sensor->registers->mask_hot_mask;
>> >> + }
>> >> +
>> >> + omap_temp_sensor_writel(temp_sensor, temp,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> +
>> >> + /* kobject_uvent to user space telling thermal threshold crossed */
>> >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
>> >> +
>> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> +
>> >> + return IRQ_HANDLED;
>> >> +}
>> >> +
>> >> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
>> >> +{
>> >> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
>> >> + struct omap_temp_sensor *temp_sensor;
>> >> + struct resource *mem;
>> >> + int ret = 0;
>> >> + int val, clk_rate;
>> >> + u32 max_freq, min_freq;
>> >> +
>> >> + if (!pdata) {
>> >> + dev_err(&pdev->dev, "platform data missing\n");
>> >> + return -EINVAL;
>> >> + }
>> >> +
>> >> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
>> >> + if (!temp_sensor)
>> >> + return -ENOMEM;
>> >> +
>> >
>> > You have error messages all over the place, Why not here ?
>>
>> Ok. I will add an error message here.
>>
>> >
>> >> + mutex_init(&temp_sensor->sensor_mutex);
>> >> +
>> >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> >> + if (!mem) {
>> >> + dev_err(&pdev->dev, "no mem resource\n");
>> >> + ret = -ENOMEM;
>> >> + goto plat_res_err;
>> >> + }
>> >> +
>> >
>> > If you try to get the resource before allocating the memory, you don't have to release
>> > the memory if the platform resource is missing.
>>
>> Ok. Here if i fail i am releasing temp_sensor memory which
>> has been allocated.
>>
>> >
>> >> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
>> >> + if (temp_sensor->irq < 0) {
>> >> + dev_err(&pdev->dev, "get_irq_byname failed\n");
>> >> + ret = temp_sensor->irq;
>> >> + goto plat_res_err;
>> >> + }
>> >> +
>> >> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>> >> + temp_sensor->clock = NULL;
>> >> + temp_sensor->registers = pdata->registers;
>> >> + temp_sensor->hwmon_dev = &pdev->dev;
>> >> +
>> >> + if (pdata->max_freq && pdata->min_freq) {
>> >> + max_freq = pdata->max_freq;
>> >> + min_freq = pdata->min_freq;
>> >> + } else {
>> >> + max_freq = MAX_FREQ;
>> >> + min_freq = MIN_FREQ;
>> >> + }
>> >> +
>> >> + pm_runtime_enable(&pdev->dev);
>> >> + pm_runtime_irq_safe(&pdev->dev);
>> >> +
>> >> + /*
>> >> + * check if the efuse has a non-zero value if not
>> >> + * it is an untrimmed sample and the temperatures
>> >> + * may not be accurate
>> >> + */
>> >> +
>> >> + if (omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_efuse)) {
>> >> + temp_sensor->is_efuse_valid = 1;
>> >
>> > is_efuse_valid is not used anywhere. Might as well drop it.
>>
>> Ok
>>
>> >
>> >> + dev_dbg(temp_sensor->hwmon_dev,
>> >> + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
>> >
>> > dev_info might be better here.
>>
>> Ok.
>>
>> >
>> >> + }
>> >> +
>> >> + dev_set_drvdata(&pdev->dev, temp_sensor);
>> >> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
>> >> + if (IS_ERR(temp_sensor->clock)) {
>> >> + ret = PTR_ERR(temp_sensor->clock);
>> >> + dev_err(temp_sensor->hwmon_dev,
>> >> + "unable to get fclk: %d\n", ret);
>> >> + goto plat_res_err;
>> >> + }
>> >> +
>> >> + ret = omap_temp_sensor_clk_enable(temp_sensor);
>> >> + if (ret) {
>> >> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
>> >
>> > omap_temp_sensor_clk_enable() already generates error messages.
>>
>> Ok. I will remove this.
>>
>> >
>> >> + goto clken_err;
>> >> + }
>> >> +
>> >> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
>> >> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
>> >> + dev_err(&pdev->dev, "Error round rate\n");
>> >> + ret = -EDOM;
>> >
>> > EDOM is wrong. Please use ENODEV.
>>
>> Ok
>>
>> >
>> > The error log doesn't really provide anything useful to the administrator.
>> > Either add parameters, or drop it.
>>
>> Ok
>>
>> >
>> >> + goto clken_err;
>> >> + }
>> >> +
>> >> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
>> >> + if (ret) {
>> >> + dev_err(&pdev->dev, "Cannot set clock rate\n");
>> >> + goto clken_err;
>> >> + }
>> >> +
>> >> + temp_sensor->clk_rate = clk_rate;
>> >> + omap_enable_continuous_mode(temp_sensor, 1);
>> >> + omap_configure_temp_sensor_thresholds(temp_sensor);
>> >> + /* 1 ms */
>> >> + omap_configure_temp_sensor_counter(temp_sensor, 1);
>> >
>> > If temp_sensor->clk_rate * 2 is two seconds, as suggested below, 1 is not 1ms.
>> > 1ms would be temp_sensor->clk_rate / 1000.
>>
>> Yes! Wrong comment. It is configured to start the temperature conversion.
>> It represents 1 clock cycle of the temperature sensor fclk. I will correct this.
>>
>> >
>> >> +
>> >> + /* Wait till the first conversion is done wait for at least 1ms */
>> >> + usleep_range(1000, 2000);
>> >> +
>> >> + /* Read the temperature once due to hw issue*/
>> >> + omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->temp_sensor_ctrl);
>> >> +
>> >> + /* Set 2 seconds time as default counter */
>> >> + omap_configure_temp_sensor_counter(temp_sensor,
>> >> + temp_sensor->clk_rate * 2);
>> >> +
>> >> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
>> >> + if (IS_ERR(temp_sensor->hwmon_dev)) {
>> >> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
>> >> + ret = PTR_ERR(temp_sensor->hwmon_dev);
>> >> + goto hwmon_reg_err;
>> >> + }
>> >> +
>> >> + ret = sysfs_create_group(&pdev->dev.kobj,
>> >> + &omap_temp_sensor_group);
>> >
>> > one line is sufficient here.
>>
>> Ok.
>>
>> >
>> >> + if (ret) {
>> >> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> >> + goto sysfs_create_err;
>> >> + }
>> >> +
>> >> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
>> >> +
>> >
>> > No other hwmon driver needs this. Doesn't the sysfs code take care of this ?
>>
>> Yes i will remove this.
>>
>> >
>> >> + ret = request_threaded_irq(temp_sensor->irq, NULL,
>> >> + omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> >> + "temp_sensor", temp_sensor);
>> >> + if (ret) {
>> >> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
>> >> + goto req_irq_err;
>> >> + }
>> >> +
>> >> + /* unmask the T_COLD and unmask T_HOT at init */
>> >> + val = omap_temp_sensor_readl(temp_sensor,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> + val |= temp_sensor->registers->mask_cold_mask
>> >> + | temp_sensor->registers->mask_hot_mask;
>> >> +
>> >> + omap_temp_sensor_writel(temp_sensor, val,
>> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> +
>> > This is racy. From Documentation/hwmon/submitting-patches:
>>
>> I read it. If i enable the interrupts before i have the sysfs
>> infrastructure ready.
>> I am likely to miss out on the uevent notification if the interrupt
>> occurs as soon as
>> i unmask. Correct me if my understanding is wrong.
>>
> See other email on sequence subject. I'll have to look into it in more detail.
> later - no time right now ...
Ok
>
> Guenter
>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 16:04 ` J, KEERTHY
@ 2011-08-25 16:19 ` Guenter Roeck
2011-08-25 16:39 ` J, KEERTHY
0 siblings, 1 reply; 19+ messages in thread
From: Guenter Roeck @ 2011-08-25 16:19 UTC (permalink / raw)
To: J, KEERTHY
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, 2011-08-25 at 12:04 -0400, J, KEERTHY wrote:
> On Thu, Aug 25, 2011 at 7:36 PM, Guenter Roeck
> <guenter.roeck@ericsson.com> wrote:
> > On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
> >> On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
> >> <guenter.roeck@ericsson.com> wrote:
> >> > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> >> >> On chip temperature sensor driver. The driver monitors the temperature of
> >> >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> >> >> the temperature crosses user defined thresholds via kobject_uevent interface.
> >> >> The user is allowed to configure the temperature thresholds vis sysfs nodes
> >> >> exposed using hwmon interface.
> >> >>
> >> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> >> >> Cc: Jean Delvare <khali@linux-fr.org>
> >> >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> >> >> Cc: lm-sensors@lm-sensors.org
> >> >
> >> > Partial review only. Too many concerns, and after a while I tend to loose track.
> >> >
> >> >> ---
> >> >> Documentation/hwmon/omap_temp_sensor | 27 +
> >> >> drivers/hwmon/Kconfig | 11 +
> >> >> drivers/hwmon/Makefile | 1 +
> >> >> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
> >> >> 4 files changed, 972 insertions(+), 0 deletions(-)
> >> >> create mode 100644 Documentation/hwmon/omap_temp_sensor
> >> >> create mode 100644 drivers/hwmon/omap_temp_sensor.c
> >> >>
> >
> > [ ... ]
> >
> >> >> +/* Sysfs hook functions */
> >> >> +
> >> >> +static ssize_t show_temp_max(struct device *dev,
> >> >> + struct device_attribute *devattr, char *buf)
> >> >> +{
> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> + int temp;
> >> >> +
> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
> >> >> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
> >> >> +
> >> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> >> >> + dev_err(dev, "invalid value\n");
> >> >> + return -EDOM;
> >> >
> >> > Please don't use EDOM, and drop the error message.
> >>
> >> The temperature is out of range. Should i use EIO?
> >>
> > It is out of range, but not due to a math error, but due to a bad reading from the chip
> > or due to a chip failure. EIO is ok.
>
> Ok
>
> >
> >> >
> >> >> + }
> >> >> +
> >> >> + temp = adc_to_temp_conversion(temp);
> >> >> +
> >> >> + return snprintf(buf, 16, "%d\n", temp);
> >> >> +}
> >> >> +
> >> >> +static ssize_t set_temp_max(struct device *dev,
> >> >> + struct device_attribute *devattr,
> >> >> + const char *buf, size_t count)
> >> >> +{
> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> + long val;
> >> >> + u32 reg_val, t_cold, t_hot, temp;
> >> >> +
> >> >> + if (strict_strtol(buf, 10, &val)) {
> >> >> + count = -EINVAL;
> >> >> + goto out;
> >> >
> >> > This will try to release the not-acquired lock.
> >>
> >> I will correct this.
> >>
> >> >
> >> >> + }
> >> >> +
> >> >> + t_hot = temp_to_adc_conversion(val);
> >> >
> >> > Bad error return check. Negative on error. Should be
> >> > if (t_hot < 0)
> >> > return t_hot;
> >>
> >> Ok.
> >>
> >> >
> >> >> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
> >> >
> >> > Unnecessary (( ))
> >>
> >> This check is unnecessary with the negative check. I will remove.
> >>
> >> >
> >> >> + count = -EINVAL;
> >> >> + goto out;
> >> >
> >> > This will try to release the not-acquired lock.
> >>
> >> I will correct this.
> >>
> >> >
> >> >> + }
> >> >> +
> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> >> + /* obtain the T cold value */
> >> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> >> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> >> +
> >> >> + if (t_hot < t_cold) {
> >> >> + count = -EINVAL;
> >> >> + goto out;
> >> >
> >> > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> >> > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> >> > change order order well defined or even possible. Applications should not have to bother about this.
> >>
> >> The hardware behavior is like this. As long as the temperature is below
> >> t_hot no interrupts are fired. Once the temperature increases above
> >> t_hot we get an
> >> interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
> >> in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
> >> interrupt only when the temperature drops below the t_cold value. Hence
> >> setting the t_cold higher than t_hot will mess up the state machine.
> >>
> >> t_hot value should be greater than t_cold value.
> >>
> > One option would be to update t_cold (max_hyst) automatically in that case.
>
> updating the t_cold without application's knowledge?
>
Why not ? Other drivers do the same. Happens all the time. Better than
returning an error and leaving the application wondering what is wrong.
> >
> > Problem here is that you expect the aplication to know, depending on the current
> > values of (max, max_hyst), how to update both limits in order. That is not a reasonable
> > expectation.
>
> The thermal application which is configuring the thresholds must be
> intelligent enough to configure the thresholds in the right order. Configuring
> the thresholds wrongly and missing the interrupt may even result in burning
> the chip.
>
Applications are generic, and _can not_ be expected to know chip
specific requirements such as order of initialization. What is needed
for your chip may be completely different for another chip, so you have
to make sure that _your driver_ prevents critical situations from
happening. You can not blame applications for not knowing the oddities
of your chips.
> >
> >> >
> >> >> + }
> >> >> +
> >> >> + /* write the new t_hot value */
> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
> >> >> + reg_val |= (t_hot <<
> >> >> + __ffs(temp_sensor->registers->threshold_thot_mask));
> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> +
> >> >> + /* Read the current temperature */
> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> >> >> +
> >> >> + /*
> >> >> + * If user sets the HIGH threshold(t_hot) greater than the current
> >> >> + * temperature(temp) unmask the HOT interrupts
> >> >> + */
> >> >> + if (t_hot > temp) {
> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> + }
> >> >> +
> >> >> + /*
> >> >> + * If current temperature is in-between the hot and cold thresholds,
> >> >> + * Enable both masks.
> >> >> + */
> >> >> + if (temp > t_cold && temp < t_hot) {
> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> + OMAP4460_BGAP_CTRL_OFFSET);
> >> >
> >> > Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
> >>
> >> Ok. I will change this.
> >>
> >> >
> >> >> + }
> >> >> + /*
> >> >> + * else no need to do anything since HW will immediately compare
> >> >> + * the new threshold and generate interrupt accordingly
> >> >> + */
> >> >> +out:
> >> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> >> +
> >> >> + return count;
> >> >> +}
> >> >> +
> >> >> +static ssize_t show_temp_max_hyst(struct device *dev,
> >> >> + struct device_attribute *devattr, char *buf)
> >> >> +{
> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> + u32 temp;
> >> >> +
> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> >
> >> > This lock would only make sense if threshold_tcold_mask can change, and if that change
> >> > would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
> >> > Besides, the code in show_temp_max() is almost the same and does not use the lock.
> >>
> >> The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
> >> ISR function. It is better to protect with mutex. I will add that in
> >> required places.
> >>
> > Reeally ? I seem to be blind. I searched for threshold_tcold_mask in the patch but
> > did not see where it is changed. Can you point me to the code ?
>
> I misread it. Yes threshold_tcold_mask is used only in show_temp_max_hyst(),
> set_temp_max(), set_temp_max_hyst() functions. It is set only in the
> set_temp_max_hyst()
> function.
>
I am still lost. Where exactly ? I don't see it being changed in
set_temp_max_hyst() either. Outside initialization code, I only see
writes to
bgap_threshold
bgap_counter
bgap_mask_ctrl
but not to any of the masks.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 16:19 ` Guenter Roeck
@ 2011-08-25 16:39 ` J, KEERTHY
2011-08-25 16:49 ` Guenter Roeck
0 siblings, 1 reply; 19+ messages in thread
From: J, KEERTHY @ 2011-08-25 16:39 UTC (permalink / raw)
To: guenter.roeck
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, Aug 25, 2011 at 9:49 PM, Guenter Roeck
<guenter.roeck@ericsson.com> wrote:
> On Thu, 2011-08-25 at 12:04 -0400, J, KEERTHY wrote:
>> On Thu, Aug 25, 2011 at 7:36 PM, Guenter Roeck
>> <guenter.roeck@ericsson.com> wrote:
>> > On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
>> >> On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
>> >> <guenter.roeck@ericsson.com> wrote:
>> >> > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
>> >> >> On chip temperature sensor driver. The driver monitors the temperature of
>> >> >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
>> >> >> the temperature crosses user defined thresholds via kobject_uevent interface.
>> >> >> The user is allowed to configure the temperature thresholds vis sysfs nodes
>> >> >> exposed using hwmon interface.
>> >> >>
>> >> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> >> >> Cc: Jean Delvare <khali@linux-fr.org>
>> >> >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> >> >> Cc: lm-sensors@lm-sensors.org
>> >> >
>> >> > Partial review only. Too many concerns, and after a while I tend to loose track.
>> >> >
>> >> >> ---
>> >> >> Documentation/hwmon/omap_temp_sensor | 27 +
>> >> >> drivers/hwmon/Kconfig | 11 +
>> >> >> drivers/hwmon/Makefile | 1 +
>> >> >> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
>> >> >> 4 files changed, 972 insertions(+), 0 deletions(-)
>> >> >> create mode 100644 Documentation/hwmon/omap_temp_sensor
>> >> >> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>> >> >>
>> >
>> > [ ... ]
>> >
>> >> >> +/* Sysfs hook functions */
>> >> >> +
>> >> >> +static ssize_t show_temp_max(struct device *dev,
>> >> >> + struct device_attribute *devattr, char *buf)
>> >> >> +{
>> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> >> + int temp;
>> >> >> +
>> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->bgap_threshold);
>> >> >> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
>> >> >> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
>> >> >> +
>> >> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> >> >> + dev_err(dev, "invalid value\n");
>> >> >> + return -EDOM;
>> >> >
>> >> > Please don't use EDOM, and drop the error message.
>> >>
>> >> The temperature is out of range. Should i use EIO?
>> >>
>> > It is out of range, but not due to a math error, but due to a bad reading from the chip
>> > or due to a chip failure. EIO is ok.
>>
>> Ok
>>
>> >
>> >> >
>> >> >> + }
>> >> >> +
>> >> >> + temp = adc_to_temp_conversion(temp);
>> >> >> +
>> >> >> + return snprintf(buf, 16, "%d\n", temp);
>> >> >> +}
>> >> >> +
>> >> >> +static ssize_t set_temp_max(struct device *dev,
>> >> >> + struct device_attribute *devattr,
>> >> >> + const char *buf, size_t count)
>> >> >> +{
>> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> >> + long val;
>> >> >> + u32 reg_val, t_cold, t_hot, temp;
>> >> >> +
>> >> >> + if (strict_strtol(buf, 10, &val)) {
>> >> >> + count = -EINVAL;
>> >> >> + goto out;
>> >> >
>> >> > This will try to release the not-acquired lock.
>> >>
>> >> I will correct this.
>> >>
>> >> >
>> >> >> + }
>> >> >> +
>> >> >> + t_hot = temp_to_adc_conversion(val);
>> >> >
>> >> > Bad error return check. Negative on error. Should be
>> >> > if (t_hot < 0)
>> >> > return t_hot;
>> >>
>> >> Ok.
>> >>
>> >> >
>> >> >> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
>> >> >
>> >> > Unnecessary (( ))
>> >>
>> >> This check is unnecessary with the negative check. I will remove.
>> >>
>> >> >
>> >> >> + count = -EINVAL;
>> >> >> + goto out;
>> >> >
>> >> > This will try to release the not-acquired lock.
>> >>
>> >> I will correct this.
>> >>
>> >> >
>> >> >> + }
>> >> >> +
>> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> >> + /* obtain the T cold value */
>> >> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->bgap_threshold);
>> >> >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
>> >> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> >> >> +
>> >> >> + if (t_hot < t_cold) {
>> >> >> + count = -EINVAL;
>> >> >> + goto out;
>> >> >
>> >> > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
>> >> > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
>> >> > change order order well defined or even possible. Applications should not have to bother about this.
>> >>
>> >> The hardware behavior is like this. As long as the temperature is below
>> >> t_hot no interrupts are fired. Once the temperature increases above
>> >> t_hot we get an
>> >> interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
>> >> in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
>> >> interrupt only when the temperature drops below the t_cold value. Hence
>> >> setting the t_cold higher than t_hot will mess up the state machine.
>> >>
>> >> t_hot value should be greater than t_cold value.
>> >>
>> > One option would be to update t_cold (max_hyst) automatically in that case.
>>
>> updating the t_cold without application's knowledge?
>>
> Why not ? Other drivers do the same. Happens all the time. Better than
> returning an error and leaving the application wondering what is wrong.
>
>> >
>> > Problem here is that you expect the aplication to know, depending on the current
>> > values of (max, max_hyst), how to update both limits in order. That is not a reasonable
>> > expectation.
>>
>> The thermal application which is configuring the thresholds must be
>> intelligent enough to configure the thresholds in the right order. Configuring
>> the thresholds wrongly and missing the interrupt may even result in burning
>> the chip.
>>
>
> Applications are generic, and _can not_ be expected to know chip
> specific requirements such as order of initialization. What is needed
> for your chip may be completely different for another chip, so you have
> to make sure that _your driver_ prevents critical situations from
> happening. You can not blame applications for not knowing the oddities
> of your chips.
>
>> >
>> >> >
>> >> >> + }
>> >> >> +
>> >> >> + /* write the new t_hot value */
>> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->bgap_threshold);
>> >> >> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
>> >> >> + reg_val |= (t_hot <<
>> >> >> + __ffs(temp_sensor->registers->threshold_thot_mask));
>> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> >> + temp_sensor->registers->bgap_threshold);
>> >> >> +
>> >> >> + /* Read the current temperature */
>> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->temp_sensor_ctrl);
>> >> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> >> >> +
>> >> >> + /*
>> >> >> + * If user sets the HIGH threshold(t_hot) greater than the current
>> >> >> + * temperature(temp) unmask the HOT interrupts
>> >> >> + */
>> >> >> + if (t_hot > temp) {
>> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> >> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
>> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> >> + }
>> >> >> +
>> >> >> + /*
>> >> >> + * If current temperature is in-between the hot and cold thresholds,
>> >> >> + * Enable both masks.
>> >> >> + */
>> >> >> + if (temp > t_cold && temp < t_hot) {
>> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> >> >> + temp_sensor->registers->bgap_mask_ctrl);
>> >> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> >> >> + OMAP4460_BGAP_CTRL_OFFSET);
>> >> >
>> >> > Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
>> >>
>> >> Ok. I will change this.
>> >>
>> >> >
>> >> >> + }
>> >> >> + /*
>> >> >> + * else no need to do anything since HW will immediately compare
>> >> >> + * the new threshold and generate interrupt accordingly
>> >> >> + */
>> >> >> +out:
>> >> >> + mutex_unlock(&temp_sensor->sensor_mutex);
>> >> >> +
>> >> >> + return count;
>> >> >> +}
>> >> >> +
>> >> >> +static ssize_t show_temp_max_hyst(struct device *dev,
>> >> >> + struct device_attribute *devattr, char *buf)
>> >> >> +{
>> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> >> >> + u32 temp;
>> >> >> +
>> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
>> >> >
>> >> > This lock would only make sense if threshold_tcold_mask can change, and if that change
>> >> > would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
>> >> > Besides, the code in show_temp_max() is almost the same and does not use the lock.
>> >>
>> >> The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
>> >> ISR function. It is better to protect with mutex. I will add that in
>> >> required places.
>> >>
>> > Reeally ? I seem to be blind. I searched for threshold_tcold_mask in the patch but
>> > did not see where it is changed. Can you point me to the code ?
>>
>> I misread it. Yes threshold_tcold_mask is used only in show_temp_max_hyst(),
>> set_temp_max(), set_temp_max_hyst() functions. It is set only in the
>> set_temp_max_hyst()
>> function.
>>
> I am still lost. Where exactly ? I don't see it being changed in
> set_temp_max_hyst() either. Outside initialization code, I only see
> writes to
> bgap_threshold
bgap_threshold is the register and "threshold_tcold_mask" is a bit field
in that register which is written in the set_temp_max_hyst() function to
configure temp_max_hyst.
Similarly "threshold_thot_mask" is a bit field in the bgap_threshold
register which is written in the set_temp_max() function to configure
temp_max.
> bgap_counter
> bgap_mask_ctrl
> but not to any of the masks.
>
> Thanks,
> Guenter
>
>
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 16:39 ` J, KEERTHY
@ 2011-08-25 16:49 ` Guenter Roeck
0 siblings, 0 replies; 19+ messages in thread
From: Guenter Roeck @ 2011-08-25 16:49 UTC (permalink / raw)
To: J, KEERTHY
Cc: linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, 2011-08-25 at 12:39 -0400, J, KEERTHY wrote:
> On Thu, Aug 25, 2011 at 9:49 PM, Guenter Roeck
> <guenter.roeck@ericsson.com> wrote:
> > On Thu, 2011-08-25 at 12:04 -0400, J, KEERTHY wrote:
> >> On Thu, Aug 25, 2011 at 7:36 PM, Guenter Roeck
> >> <guenter.roeck@ericsson.com> wrote:
> >> > On Thu, Aug 25, 2011 at 06:30:07AM -0400, J, KEERTHY wrote:
> >> >> On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
> >> >> <guenter.roeck@ericsson.com> wrote:
> >> >> > On Wed, Aug 24, 2011 at 10:37:12AM -0400, Keerthy wrote:
> >> >> >> On chip temperature sensor driver. The driver monitors the temperature of
> >> >> >> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> >> >> >> the temperature crosses user defined thresholds via kobject_uevent interface.
> >> >> >> The user is allowed to configure the temperature thresholds vis sysfs nodes
> >> >> >> exposed using hwmon interface.
> >> >> >>
> >> >> >> Signed-off-by: Keerthy <j-keerthy@ti.com>
> >> >> >> Cc: Jean Delvare <khali@linux-fr.org>
> >> >> >> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> >> >> >> Cc: lm-sensors@lm-sensors.org
> >> >> >
> >> >> > Partial review only. Too many concerns, and after a while I tend to loose track.
> >> >> >
> >> >> >> ---
> >> >> >> Documentation/hwmon/omap_temp_sensor | 27 +
> >> >> >> drivers/hwmon/Kconfig | 11 +
> >> >> >> drivers/hwmon/Makefile | 1 +
> >> >> >> drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
> >> >> >> 4 files changed, 972 insertions(+), 0 deletions(-)
> >> >> >> create mode 100644 Documentation/hwmon/omap_temp_sensor
> >> >> >> create mode 100644 drivers/hwmon/omap_temp_sensor.c
> >> >> >>
> >> >
> >> > [ ... ]
> >> >
> >> >> >> +/* Sysfs hook functions */
> >> >> >> +
> >> >> >> +static ssize_t show_temp_max(struct device *dev,
> >> >> >> + struct device_attribute *devattr, char *buf)
> >> >> >> +{
> >> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> >> + int temp;
> >> >> >> +
> >> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> >> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
> >> >> >> + >> __ffs(temp_sensor->registers->threshold_thot_mask);
> >> >> >> +
> >> >> >> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> >> >> >> + dev_err(dev, "invalid value\n");
> >> >> >> + return -EDOM;
> >> >> >
> >> >> > Please don't use EDOM, and drop the error message.
> >> >>
> >> >> The temperature is out of range. Should i use EIO?
> >> >>
> >> > It is out of range, but not due to a math error, but due to a bad reading from the chip
> >> > or due to a chip failure. EIO is ok.
> >>
> >> Ok
> >>
> >> >
> >> >> >
> >> >> >> + }
> >> >> >> +
> >> >> >> + temp = adc_to_temp_conversion(temp);
> >> >> >> +
> >> >> >> + return snprintf(buf, 16, "%d\n", temp);
> >> >> >> +}
> >> >> >> +
> >> >> >> +static ssize_t set_temp_max(struct device *dev,
> >> >> >> + struct device_attribute *devattr,
> >> >> >> + const char *buf, size_t count)
> >> >> >> +{
> >> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> >> + long val;
> >> >> >> + u32 reg_val, t_cold, t_hot, temp;
> >> >> >> +
> >> >> >> + if (strict_strtol(buf, 10, &val)) {
> >> >> >> + count = -EINVAL;
> >> >> >> + goto out;
> >> >> >
> >> >> > This will try to release the not-acquired lock.
> >> >>
> >> >> I will correct this.
> >> >>
> >> >> >
> >> >> >> + }
> >> >> >> +
> >> >> >> + t_hot = temp_to_adc_conversion(val);
> >> >> >
> >> >> > Bad error return check. Negative on error. Should be
> >> >> > if (t_hot < 0)
> >> >> > return t_hot;
> >> >>
> >> >> Ok.
> >> >>
> >> >> >
> >> >> >> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
> >> >> >
> >> >> > Unnecessary (( ))
> >> >>
> >> >> This check is unnecessary with the negative check. I will remove.
> >> >>
> >> >> >
> >> >> >> + count = -EINVAL;
> >> >> >> + goto out;
> >> >> >
> >> >> > This will try to release the not-acquired lock.
> >> >>
> >> >> I will correct this.
> >> >>
> >> >> >
> >> >> >> + }
> >> >> >> +
> >> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> >> >> + /* obtain the T cold value */
> >> >> >> + t_cold = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> >> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> >> >> >> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> >> >> >> +
> >> >> >> + if (t_hot < t_cold) {
> >> >> >> + count = -EINVAL;
> >> >> >> + goto out;
> >> >> >
> >> >> > Context specific limitations like this one are not a good idea, since it assumes an order of changing max
> >> >> > and max_hysteresis which is not necessarily guaranteed by the application making the change, nor is a
> >> >> > change order order well defined or even possible. Applications should not have to bother about this.
> >> >>
> >> >> The hardware behavior is like this. As long as the temperature is below
> >> >> t_hot no interrupts are fired. Once the temperature increases above
> >> >> t_hot we get an
> >> >> interrupt. In order to avoid repeated interrupts we mask the t_hot interrupt
> >> >> in the interrupt handler and enable the t_cold interrupts. So we get a t_cold
> >> >> interrupt only when the temperature drops below the t_cold value. Hence
> >> >> setting the t_cold higher than t_hot will mess up the state machine.
> >> >>
> >> >> t_hot value should be greater than t_cold value.
> >> >>
> >> > One option would be to update t_cold (max_hyst) automatically in that case.
> >>
> >> updating the t_cold without application's knowledge?
> >>
> > Why not ? Other drivers do the same. Happens all the time. Better than
> > returning an error and leaving the application wondering what is wrong.
> >
> >> >
> >> > Problem here is that you expect the aplication to know, depending on the current
> >> > values of (max, max_hyst), how to update both limits in order. That is not a reasonable
> >> > expectation.
> >>
> >> The thermal application which is configuring the thresholds must be
> >> intelligent enough to configure the thresholds in the right order. Configuring
> >> the thresholds wrongly and missing the interrupt may even result in burning
> >> the chip.
> >>
> >
> > Applications are generic, and _can not_ be expected to know chip
> > specific requirements such as order of initialization. What is needed
> > for your chip may be completely different for another chip, so you have
> > to make sure that _your driver_ prevents critical situations from
> > happening. You can not blame applications for not knowing the oddities
> > of your chips.
> >
> >> >
> >> >> >
> >> >> >> + }
> >> >> >> +
> >> >> >> + /* write the new t_hot value */
> >> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> >> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
> >> >> >> + reg_val |= (t_hot <<
> >> >> >> + __ffs(temp_sensor->registers->threshold_thot_mask));
> >> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> >> + temp_sensor->registers->bgap_threshold);
> >> >> >> +
> >> >> >> + /* Read the current temperature */
> >> >> >> + temp = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->temp_sensor_ctrl);
> >> >> >> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> >> >> >> +
> >> >> >> + /*
> >> >> >> + * If user sets the HIGH threshold(t_hot) greater than the current
> >> >> >> + * temperature(temp) unmask the HOT interrupts
> >> >> >> + */
> >> >> >> + if (t_hot > temp) {
> >> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> >> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> >> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> >> + }
> >> >> >> +
> >> >> >> + /*
> >> >> >> + * If current temperature is in-between the hot and cold thresholds,
> >> >> >> + * Enable both masks.
> >> >> >> + */
> >> >> >> + if (temp > t_cold && temp < t_hot) {
> >> >> >> + reg_val = omap_temp_sensor_readl(temp_sensor,
> >> >> >> + temp_sensor->registers->bgap_mask_ctrl);
> >> >> >> + reg_val |= temp_sensor->registers->mask_cold_mask;
> >> >> >> + reg_val |= temp_sensor->registers->mask_hot_mask;
> >> >> >> + omap_temp_sensor_writel(temp_sensor, reg_val,
> >> >> >> + OMAP4460_BGAP_CTRL_OFFSET);
> >> >> >
> >> >> > Why use OMAP4460_BGAP_CTRL_OFFSET here but bgap_mask_ctrl elsewhere ?
> >> >>
> >> >> Ok. I will change this.
> >> >>
> >> >> >
> >> >> >> + }
> >> >> >> + /*
> >> >> >> + * else no need to do anything since HW will immediately compare
> >> >> >> + * the new threshold and generate interrupt accordingly
> >> >> >> + */
> >> >> >> +out:
> >> >> >> + mutex_unlock(&temp_sensor->sensor_mutex);
> >> >> >> +
> >> >> >> + return count;
> >> >> >> +}
> >> >> >> +
> >> >> >> +static ssize_t show_temp_max_hyst(struct device *dev,
> >> >> >> + struct device_attribute *devattr, char *buf)
> >> >> >> +{
> >> >> >> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> >> >> >> + u32 temp;
> >> >> >> +
> >> >> >> + mutex_lock(&temp_sensor->sensor_mutex);
> >> >> >
> >> >> > This lock would only make sense if threshold_tcold_mask can change, and if that change
> >> >> > would be protected by the mutex. I don't see that to be the case, thus the lock is unnecessary.
> >> >> > Besides, the code in show_temp_max() is almost the same and does not use the lock.
> >> >>
> >> >> The masks are getting changed in show_temp_max() show_temp_max_hyst() and the
> >> >> ISR function. It is better to protect with mutex. I will add that in
> >> >> required places.
> >> >>
> >> > Reeally ? I seem to be blind. I searched for threshold_tcold_mask in the patch but
> >> > did not see where it is changed. Can you point me to the code ?
> >>
> >> I misread it. Yes threshold_tcold_mask is used only in show_temp_max_hyst(),
> >> set_temp_max(), set_temp_max_hyst() functions. It is set only in the
> >> set_temp_max_hyst()
> >> function.
> >>
> > I am still lost. Where exactly ? I don't see it being changed in
> > set_temp_max_hyst() either. Outside initialization code, I only see
> > writes to
> > bgap_threshold
>
> bgap_threshold is the register and "threshold_tcold_mask" is a bit field
> in that register which is written in the set_temp_max_hyst() function to
> configure temp_max_hyst.
> Similarly "threshold_thot_mask" is a bit field in the bgap_threshold
> register which is written in the set_temp_max() function to configure
> temp_max.
Sure, but the mask itself is not changed, which would be the only reason
for needing the mutex. Just writing/reading a single register does not
require a mutex, since a single read is atomic, and it doesn't matter if
the reader gets the new or the old value.
It would be different if the mask was changed, or if you would need to
read a sequence of registers depending on each other.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 0/6 V3] OMAP4: Temperature sensor driver
@ 2011-08-24 14:37 Keerthy
2011-08-24 14:37 ` [PATCH 6/6 V3] hwmon: OMAP4: On die temperature " Keerthy
0 siblings, 1 reply; 19+ messages in thread
From: Keerthy @ 2011-08-24 14:37 UTC (permalink / raw)
To: linux-omap; +Cc: Keerthy
The patch series for the on die temperature sensor driver.
The patch set has the device file, omap4 on die temperature sensor
hwmon driver. hwmod, clk support. The patch set compiles
on top of LO tree Master branch.
This patch series is tested for boot-up on OMAP4460. The temperature
reading and the interrupts generation on crossing the temperature
thresholds also tested.
V3:
(1) Fixed comments on the return values in the device file
(2) Removed unnecessary error messages.
(3) Redundant braces removed.
(4) Implemented binary search in place of linear for temp to adc conversion.
(5) Wrong usage of EINVAL corrected.
V2:
(1) Fixed comments on return values in the driver.
(2) Moved the TEMPSOFF setting code to the activate/deactivate hooks.
(3) Used idr to pass for the device id.
Benoit Cousson (1):
OMAP4: Hwmod: OMAP temperature sensor
Keerthy (5):
OMAP4: Clock: Associate clocks for OMAP temperature sensor
OMAP4: Adding the temperature sensor register set bit fields
OMAP4460: Temperature sensor data
OMAP4: Temperature sensor device support
hwmon: OMAP4: On die temperature sensor driver
Documentation/hwmon/omap_temp_sensor | 27 +
arch/arm/mach-omap2/Makefile | 3 +-
arch/arm/mach-omap2/clock44xx_data.c | 2 +-
.../include/mach/ctrl_module_core_44xx.h | 70 ++-
arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 61 ++
arch/arm/mach-omap2/temp_sensor4460_data.c | 63 ++
arch/arm/mach-omap2/temp_sensor_device.c | 188 ++++
arch/arm/plat-omap/Kconfig | 12 +
.../plat-omap/include/plat/temperature_sensor.h | 93 ++
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++
12 files changed, 1449 insertions(+), 15 deletions(-)
create mode 100644 Documentation/hwmon/omap_temp_sensor
create mode 100644 arch/arm/mach-omap2/temp_sensor4460_data.c
create mode 100644 arch/arm/mach-omap2/temp_sensor_device.c
create mode 100644 arch/arm/plat-omap/include/plat/temperature_sensor.h
create mode 100644 drivers/hwmon/omap_temp_sensor.c
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 14:37 [PATCH 0/6 V3] OMAP4: Temperature " Keerthy
@ 2011-08-24 14:37 ` Keerthy
2011-08-24 16:36 ` Janakiram Sistla
2011-08-25 7:24 ` Todd Poynor
0 siblings, 2 replies; 19+ messages in thread
From: Keerthy @ 2011-08-24 14:37 UTC (permalink / raw)
To: linux-omap; +Cc: Keerthy, Jean Delvare, Guenter Roeck, lm-sensors
On chip temperature sensor driver. The driver monitors the temperature of
the MPU subsystem of the OMAP4. It sends notifications to the user space if
the temperature crosses user defined thresholds via kobject_uevent interface.
The user is allowed to configure the temperature thresholds vis sysfs nodes
exposed using hwmon interface.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: lm-sensors@lm-sensors.org
---
Documentation/hwmon/omap_temp_sensor | 27 +
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/omap_temp_sensor.c | 933 ++++++++++++++++++++++++++++++++++
4 files changed, 972 insertions(+), 0 deletions(-)
create mode 100644 Documentation/hwmon/omap_temp_sensor
create mode 100644 drivers/hwmon/omap_temp_sensor.c
diff --git a/Documentation/hwmon/omap_temp_sensor b/Documentation/hwmon/omap_temp_sensor
new file mode 100644
index 0000000..e01a6d6
--- /dev/null
+++ b/Documentation/hwmon/omap_temp_sensor
@@ -0,0 +1,27 @@
+Kernel driver omap_temp_sensor
+==============================
+
+Supported chips:
+ * Texas Instruments OMAP4460
+ Prefix: 'omap_temp_sensor'
+ Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
+
+Author:
+ J Keerthy <j-keerthy@ti.com>
+
+Description
+-----------
+
+The Texas Instruments OMAP4 family of chips have a bandgap temperature sensor.
+The temperature sensor feature is used to convert the temperature of the device
+into a decimal value coded on 10 bits. An internal ADC is used for conversion.
+The recommended operating temperatures must be in the range -40 degree Celsius
+to 123 degree celsius for standard conversion.
+The thresholds are programmable and upon crossing the thresholds an interrupt
+is generated. The OMAP temperature sensor has a programmable update rate in
+milli seconds.
+(Currently the driver programs a default of 2000 milli seconds).
+
+The driver provides the common sysfs-interface for temperatures (see
+Documentation/hwmon/sysfs-interface under Temperatures).
+
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5f888f7..9c9cd8b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -323,6 +323,17 @@ config SENSORS_F71805F
This driver can also be built as a module. If so, the module
will be called f71805f.
+config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
+ bool "OMAP on-die temperature sensor hwmon driver"
+ depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
+ help
+ If you say yes here you get support for hardware
+ monitoring features of the OMAP on die temperature
+ sensor.
+
+ Continuous conversion programmable delay
+ mode is used for temperature conversion.
+
config SENSORS_F71882FG
tristate "Fintek F71882FG and compatibles"
help
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 28061cf..d0f89f5 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
diff --git a/drivers/hwmon/omap_temp_sensor.c b/drivers/hwmon/omap_temp_sensor.c
new file mode 100644
index 0000000..66fb3a9
--- /dev/null
+++ b/drivers/hwmon/omap_temp_sensor.c
@@ -0,0 +1,933 @@
+/*
+ * OMAP4 Temperature sensor driver file
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: J Keerthy <j-keerthy@ti.com>
+ * Author: Moiz Sonasath <m-sonasath@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <plat/omap_device.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/stddef.h>
+#include <linux/sysfs.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/delay.h>
+#include <plat/temperature_sensor.h>
+
+#define TSHUT_HOT 920 /* 122 deg C */
+#define TSHUT_COLD 866 /* 100 deg C */
+#define T_HOT 800 /* 73 deg C */
+#define T_COLD 795 /* 71 deg C */
+#define OMAP_ADC_START_VALUE 530
+#define OMAP_ADC_END_VALUE 923
+#define MAX_FREQ 2000000
+#define MIN_FREQ 1000000
+
+/*
+ * omap_temp_sensor structure
+ * @hwmon_dev - device pointer
+ * @clock - Clock pointer
+ * @registers - Pointer to structure with register offsets and bitfields
+ * @sensor_mutex - Mutex for sysfs, irq and PM
+ * @irq - MPU Irq number for thermal alert
+ * @phy_base - Physical base of the temp I/O
+ * @clk_rate - Holds current clock rate
+ * @temp_sensor_ctrl - temp sensor control register value
+ * @bg_ctrl - bandgap ctrl register value
+ * @bg_counter - bandgap counter value
+ * @bg_threshold - bandgap threshold register value
+ * @temp_sensor_tshut_threshold - bandgap tshut register value
+ * @is_efuse_valid - Flag to determine if efuse is valid or not
+ * @clk_on - Manages the current clock state
+ */
+struct omap_temp_sensor {
+ struct device *hwmon_dev;
+ struct clk *clock;
+ struct omap_temp_sensor_registers *registers;
+ struct mutex sensor_mutex; /* Mutex for sysfs, irq and PM */
+ unsigned int irq;
+ void __iomem *phy_base;
+ u32 clk_rate;
+ u32 temp_sensor_ctrl;
+ u32 bg_ctrl;
+ u32 bg_counter;
+ u32 bg_threshold;
+ u32 temp_sensor_tshut_threshold;
+ bool is_efuse_valid;
+ bool clk_on;
+};
+
+/*
+ * Temperature values in milli degree celsius
+ * ADC code values from 530 to 923
+ */
+static int adc_to_temp[] = {
+ -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200,
+ -37800, -37300, -36800, -36400, -36000, -35600, -35200, -34800,
+ -34300, -33800, -33400, -33000, -32600, -32200, -31800, -31300,
+ -30800, -30400, -30000, -29600, -29200, -28700, -28200, -27800,
+ -27400, -27000, -26600, -26200, -25700, -25200, -24800, -24400,
+ -24000, -23600, -23200, -22700, -22200, -21800, -21400, -21000,
+ -20600, -20200, -19700, -19200, -18800, -18400, -18000, -17600,
+ -17200, -16700, -16200, -15800, -15400, -15000, -14600, -14200,
+ -13700, -13200, -12800, -12400, -12000, -11600, -11200, -10700,
+ -10200, -9800, -9400, -9000, -8600, -8200, -7700, -7200, -6800,
+ -6400, -6000, -5600, -5200, -4800, -4300, -3800, -3400, -3000,
+ -2600, -2200, -1800, -1300, -800, -400, 0, 400, 800, 1200, 1600,
+ 2100, 2600, 3000, 3400, 3800, 4200, 4600, 5100, 5600, 6000, 6400,
+ 6800, 7200, 7600, 8000, 8500, 9000, 9400, 9800, 10200, 10600, 11000,
+ 11400, 11900, 12400, 12800, 13200, 13600, 14000, 14400, 14800,
+ 15300, 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18700,
+ 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22100, 22600,
+ 23000, 23400, 23800, 24200, 24600, 25000, 25400, 25900, 26400,
+ 26800, 27200, 27600, 28000, 28400, 28800, 29300, 29800, 30200,
+ 30600, 31000, 31400, 31800, 32200, 32600, 33100, 33600, 34000,
+ 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37300, 37800,
+ 38200, 38600, 39000, 39400, 39800, 40200, 40600, 41100, 41600,
+ 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45300,
+ 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 49000,
+ 49500, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800,
+ 53200, 53700, 54200, 54600, 55000, 55400, 55800, 56200, 56600,
+ 57000, 57400, 57800, 58200, 58700, 59200, 59600, 60000, 60400,
+ 60800, 61200, 61600, 62000, 62400, 62800, 63300, 63800, 64200,
+ 64600, 65000, 65400, 65800, 66200, 66600, 67000, 67400, 67800,
+ 68200, 68700, 69200, 69600, 70000, 70400, 70800, 71200, 71600,
+ 72000, 72400, 72800, 73200, 73600, 74100, 74600, 75000, 75400,
+ 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600, 79000,
+ 79400, 79800, 80300, 80800, 81200, 81600, 82000, 82400, 82800,
+ 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400,
+ 86800, 87300, 87800, 88200, 88600, 89000, 89400, 89800, 90200,
+ 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 93800,
+ 94200, 94600, 95000, 95500, 96000, 96400, 96800, 97200, 97600,
+ 98000, 98400, 98800, 99200, 99600, 100000, 100400, 100800, 101200,
+ 101600, 102000, 102400, 102800, 103200, 103600, 104000, 104400,
+ 104800, 105200, 105600, 106100, 106600, 107000, 107400, 107800,
+ 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
+ 111400, 111800, 112200, 112600, 113000, 113400, 113800, 114200,
+ 114600, 115000, 115400, 115800, 116200, 116600, 117000, 117400,
+ 117800, 118200, 118600, 119000, 119400, 119800, 120200, 120600,
+ 121000, 121400, 121800, 122200, 122600, 123000
+};
+
+static unsigned long omap_temp_sensor_readl(struct omap_temp_sensor
+ *temp_sensor, u32 reg)
+{
+ return __raw_readl(temp_sensor->phy_base + reg);
+}
+
+static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
+ u32 val, u32 reg)
+{
+ __raw_writel(val, (temp_sensor->phy_base + reg));
+}
+
+static int adc_to_temp_conversion(int adc_val)
+{
+ return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
+}
+
+static int temp_to_adc_conversion(long temp)
+{
+ int high, low, mid;
+
+ if (temp < adc_to_temp[0] ||
+ temp > adc_to_temp[OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE])
+ return -EINVAL;
+
+ high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
+ low = 0;
+ mid = (high + low) / 2;
+
+ while (low < high) {
+ if (temp < adc_to_temp[mid])
+ high = mid - 1;
+ else
+ low = mid + 1;
+ mid = (low + high) / 2;
+ }
+
+ return OMAP_ADC_START_VALUE + low;
+}
+
+static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
+ *temp_sensor)
+{
+ u32 temp;
+
+ /* Configure the TALERT thresholds */
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ temp |= (T_HOT << __ffs(temp_sensor->registers->threshold_thot_mask)) |
+ (T_COLD << __ffs(temp_sensor->registers->threshold_tcold_mask));
+ omap_temp_sensor_writel(temp_sensor, temp,
+ temp_sensor->registers->bgap_threshold);
+
+ /* Configure the TSHUT thresholds */
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->thsut_threshold);
+ temp |= (TSHUT_HOT << __ffs(temp_sensor->registers->tshut_hot_mask))
+ | (TSHUT_COLD << __ffs(temp_sensor->registers->tshut_hot_mask));
+ omap_temp_sensor_writel(temp_sensor, temp,
+ temp_sensor->registers->thsut_threshold);
+}
+
+static void omap_configure_temp_sensor_counter(struct omap_temp_sensor
+ *temp_sensor, u32 counter)
+{
+ u32 val;
+
+ val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_counter);
+ val &= ~temp_sensor->registers->counter_mask;
+ val |= counter << __ffs(temp_sensor->registers->counter_mask);
+ omap_temp_sensor_writel(temp_sensor, val,
+ temp_sensor->registers->bgap_counter);
+}
+
+static void omap_enable_continuous_mode(struct omap_temp_sensor *temp_sensor,
+ bool enable)
+{
+ u32 val;
+
+ val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mode_ctrl);
+
+ if (enable)
+ val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
+ else
+ val &= ~temp_sensor->registers->mode_ctrl_mask;
+
+ omap_temp_sensor_writel(temp_sensor, val,
+ temp_sensor->registers->bgap_mode_ctrl);
+}
+
+/* Sysfs hook functions */
+
+static ssize_t show_temp_max(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ int temp;
+
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ temp = (temp & temp_sensor->registers->threshold_thot_mask)
+ >> __ffs(temp_sensor->registers->threshold_thot_mask);
+
+ if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
+ dev_err(dev, "invalid value\n");
+ return -EDOM;
+ }
+
+ temp = adc_to_temp_conversion(temp);
+
+ return snprintf(buf, 16, "%d\n", temp);
+}
+
+static ssize_t set_temp_max(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ long val;
+ u32 reg_val, t_cold, t_hot, temp;
+
+ if (strict_strtol(buf, 10, &val)) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ t_hot = temp_to_adc_conversion(val);
+ if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ /* obtain the T cold value */
+ t_cold = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
+ __ffs(temp_sensor->registers->threshold_tcold_mask);
+
+ if (t_hot < t_cold) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ /* write the new t_hot value */
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ reg_val &= ~temp_sensor->registers->threshold_thot_mask;
+ reg_val |= (t_hot <<
+ __ffs(temp_sensor->registers->threshold_thot_mask));
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_threshold);
+
+ /* Read the current temperature */
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->temp_sensor_ctrl);
+ temp &= temp_sensor->registers->bgap_dtemp_mask;
+
+ /*
+ * If user sets the HIGH threshold(t_hot) greater than the current
+ * temperature(temp) unmask the HOT interrupts
+ */
+ if (t_hot > temp) {
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ reg_val &= ~temp_sensor->registers->mask_cold_mask;
+ reg_val |= temp_sensor->registers->mask_hot_mask;
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_mask_ctrl);
+ }
+
+ /*
+ * If current temperature is in-between the hot and cold thresholds,
+ * Enable both masks.
+ */
+ if (temp > t_cold && temp < t_hot) {
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ reg_val |= temp_sensor->registers->mask_cold_mask;
+ reg_val |= temp_sensor->registers->mask_hot_mask;
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ OMAP4460_BGAP_CTRL_OFFSET);
+ }
+ /*
+ * else no need to do anything since HW will immediately compare
+ * the new threshold and generate interrupt accordingly
+ */
+out:
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+ return count;
+}
+
+static ssize_t show_temp_max_hyst(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ u32 temp;
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
+ __ffs(temp_sensor->registers->threshold_tcold_mask);
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+ if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
+ dev_err(dev, "invalid value\n");
+ return -EDOM;
+ }
+
+ temp = adc_to_temp_conversion(temp);
+
+ return snprintf(buf, 16, "%d\n", temp);
+}
+
+static ssize_t set_temp_max_hyst(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ u32 reg_val, t_hot, t_cold, temp;
+ long val;
+
+ if (strict_strtol(buf, 10, &val)) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ t_cold = temp_to_adc_conversion(val);
+ if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ /* obtain the T HOT value */
+ t_hot = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
+ __ffs(temp_sensor->registers->threshold_thot_mask);
+
+ if (t_cold > t_hot) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ /* write the new t_cold value */
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
+ reg_val |= t_cold <<
+ __ffs(temp_sensor->registers->threshold_tcold_mask);
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_threshold);
+
+ /* Read the current temperature */
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->temp_sensor_ctrl);
+ temp &= temp_sensor->registers->bgap_dtemp_mask;
+
+ /*
+ * If user sets the LOW threshold(t_cold) lower than the current
+ * temperature(temp) unmask the COLD interrupts
+ */
+ if (t_cold < temp) {
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ reg_val &= ~temp_sensor->registers->mask_hot_mask;
+ reg_val |= temp_sensor->registers->mask_cold_mask;
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_mask_ctrl);
+ }
+
+ /*
+ * If current temperature is in-between the hot and cold thresholds,
+ * Enable both masks.
+ */
+ if (temp < t_hot && temp > t_cold) {
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ reg_val |= temp_sensor->registers->mask_cold_mask;
+ reg_val |= temp_sensor->registers->mask_hot_mask;
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_mask_ctrl);
+ }
+
+ /*
+ * else no need to do anything since HW will immediately compare
+ * the new threshold and generate interrupt accordingly
+ */
+
+out:
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+ return count;
+}
+
+static ssize_t show_update_rate(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ u32 temp = 0, ret = 0;
+
+
+ if (!temp_sensor->clk_rate) {
+ dev_err(dev, "clk_rate is NULL\n");
+ ret = -EDOM;
+ goto out;
+ }
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_counter);
+ temp = (temp & temp_sensor->registers->counter_mask) >>
+ __ffs(temp_sensor->registers->counter_mask);
+ mutex_unlock(&temp_sensor->sensor_mutex);
+ temp = temp * 1000 / temp_sensor->clk_rate;
+
+out:
+ if (!ret)
+ return sprintf(buf, "%d\n", temp);
+
+ return ret;
+}
+
+static ssize_t set_update_rate(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ u32 reg_val;
+ long val;
+
+ if (strict_strtol(buf, 10, &val)) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ val *= temp_sensor->clk_rate / 1000;
+ mutex_lock(&temp_sensor->sensor_mutex);
+ reg_val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_counter);
+
+ reg_val &= ~temp_sensor->registers->counter_mask;
+ reg_val |= val;
+ omap_temp_sensor_writel(temp_sensor, reg_val,
+ temp_sensor->registers->bgap_counter);
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+out:
+ return count;
+}
+
+static int omap_temp_sensor_read_temp(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+ int temp, ret = 0;
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->temp_sensor_ctrl);
+ temp &= temp_sensor->registers->bgap_dtemp_mask;
+
+ /* look up for temperature in the table and return the temperature */
+ if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
+ dev_err(dev, "invalid adc code reported %d", temp);
+ ret = -EDOM;
+ goto out;
+ }
+
+ temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
+
+out:
+ mutex_unlock(&temp_sensor->sensor_mutex);
+ if (!ret)
+ return sprintf(buf, "%d\n", temp);
+
+ return ret;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, omap_temp_sensor_read_temp,
+ NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
+ set_temp_max, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_max_hyst,
+ set_temp_max_hyst, 0);
+static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO, show_update_rate,
+ set_update_rate, 0);
+
+static struct attribute *omap_temp_sensor_attributes[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp1_max.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+ &sensor_dev_attr_update_rate.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group omap_temp_sensor_group = {
+ .attrs = omap_temp_sensor_attributes,
+};
+
+static int omap_temp_sensor_clk_enable(struct omap_temp_sensor *temp_sensor)
+{
+ u32 ret = 0;
+
+ if (temp_sensor->clk_on) {
+ dev_err(temp_sensor->hwmon_dev, "clock already on\n");
+ goto out;
+ }
+
+ ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
+ if (ret < 0) {
+ dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
+ goto out;
+ }
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ temp_sensor->clk_on = 1;
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+out:
+ return ret;
+}
+
+static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
+{
+ u32 ret = 0;
+
+ if (!temp_sensor->clk_on) {
+ dev_err(temp_sensor->hwmon_dev, "clock already off\n");
+ goto out;
+ }
+
+ /* Gate the clock */
+ ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
+ if (ret < 0) {
+ dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
+ goto out;
+ }
+
+ mutex_lock(&temp_sensor->sensor_mutex);
+ temp_sensor->clk_on = 0;
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+out:
+ return ret;
+}
+
+static irqreturn_t omap_talert_irq_handler(int irq, void *data)
+{
+ struct omap_temp_sensor *temp_sensor;
+ int t_hot, t_cold, temp;
+
+ temp_sensor = data;
+ mutex_lock(&temp_sensor->sensor_mutex);
+
+ /* Read the status of t_hot */
+ t_hot = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_status)
+ & temp_sensor->registers->status_hot_mask;
+
+ /* Read the status of t_cold */
+ t_cold = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_status)
+ & temp_sensor->registers->status_cold_mask;
+
+ temp = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ /*
+ * One TALERT interrupt: Two sources
+ * If the interrupt is due to t_hot then mask t_hot and
+ * and unmask t_cold else mask t_cold and unmask t_hot
+ */
+ if (t_hot) {
+ temp &= ~temp_sensor->registers->mask_hot_mask;
+ temp |= temp_sensor->registers->mask_cold_mask;
+ } else if (t_cold) {
+ temp &= ~temp_sensor->registers->mask_cold_mask;
+ temp |= temp_sensor->registers->mask_hot_mask;
+ }
+
+ omap_temp_sensor_writel(temp_sensor, temp,
+ temp_sensor->registers->bgap_mask_ctrl);
+
+ /* kobject_uvent to user space telling thermal threshold crossed */
+ kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
+
+ mutex_unlock(&temp_sensor->sensor_mutex);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
+{
+ struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
+ struct omap_temp_sensor *temp_sensor;
+ struct resource *mem;
+ int ret = 0;
+ int val, clk_rate;
+ u32 max_freq, min_freq;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform data missing\n");
+ return -EINVAL;
+ }
+
+ temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
+ if (!temp_sensor)
+ return -ENOMEM;
+
+ mutex_init(&temp_sensor->sensor_mutex);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "no mem resource\n");
+ ret = -ENOMEM;
+ goto plat_res_err;
+ }
+
+ temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
+ if (temp_sensor->irq < 0) {
+ dev_err(&pdev->dev, "get_irq_byname failed\n");
+ ret = temp_sensor->irq;
+ goto plat_res_err;
+ }
+
+ temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
+ temp_sensor->clock = NULL;
+ temp_sensor->registers = pdata->registers;
+ temp_sensor->hwmon_dev = &pdev->dev;
+
+ if (pdata->max_freq && pdata->min_freq) {
+ max_freq = pdata->max_freq;
+ min_freq = pdata->min_freq;
+ } else {
+ max_freq = MAX_FREQ;
+ min_freq = MIN_FREQ;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_irq_safe(&pdev->dev);
+
+ /*
+ * check if the efuse has a non-zero value if not
+ * it is an untrimmed sample and the temperatures
+ * may not be accurate
+ */
+
+ if (omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_efuse)) {
+ temp_sensor->is_efuse_valid = 1;
+ dev_dbg(temp_sensor->hwmon_dev,
+ "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
+ }
+
+ dev_set_drvdata(&pdev->dev, temp_sensor);
+ temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
+ if (IS_ERR(temp_sensor->clock)) {
+ ret = PTR_ERR(temp_sensor->clock);
+ dev_err(temp_sensor->hwmon_dev,
+ "unable to get fclk: %d\n", ret);
+ goto plat_res_err;
+ }
+
+ ret = omap_temp_sensor_clk_enable(temp_sensor);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot enable temp sensor\n");
+ goto clken_err;
+ }
+
+ clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
+ if (clk_rate < min_freq || clk_rate == 0xffffffff) {
+ dev_err(&pdev->dev, "Error round rate\n");
+ ret = -EDOM;
+ goto clken_err;
+ }
+
+ ret = clk_set_rate(temp_sensor->clock, clk_rate);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot set clock rate\n");
+ goto clken_err;
+ }
+
+ temp_sensor->clk_rate = clk_rate;
+ omap_enable_continuous_mode(temp_sensor, 1);
+ omap_configure_temp_sensor_thresholds(temp_sensor);
+ /* 1 ms */
+ omap_configure_temp_sensor_counter(temp_sensor, 1);
+
+ /* Wait till the first conversion is done wait for at least 1ms */
+ usleep_range(1000, 2000);
+
+ /* Read the temperature once due to hw issue*/
+ omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->temp_sensor_ctrl);
+
+ /* Set 2 seconds time as default counter */
+ omap_configure_temp_sensor_counter(temp_sensor,
+ temp_sensor->clk_rate * 2);
+
+ temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
+ if (IS_ERR(temp_sensor->hwmon_dev)) {
+ dev_err(&pdev->dev, "hwmon_device_register failed.\n");
+ ret = PTR_ERR(temp_sensor->hwmon_dev);
+ goto hwmon_reg_err;
+ }
+
+ ret = sysfs_create_group(&pdev->dev.kobj,
+ &omap_temp_sensor_group);
+ if (ret) {
+ dev_err(&pdev->dev, "could not create sysfs files\n");
+ goto sysfs_create_err;
+ }
+
+ kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
+
+ ret = request_threaded_irq(temp_sensor->irq, NULL,
+ omap_talert_irq_handler, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ "temp_sensor", temp_sensor);
+ if (ret) {
+ dev_err(&pdev->dev, "Request threaded irq failed.\n");
+ goto req_irq_err;
+ }
+
+ /* unmask the T_COLD and unmask T_HOT at init */
+ val = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ val |= temp_sensor->registers->mask_cold_mask
+ | temp_sensor->registers->mask_hot_mask;
+
+ omap_temp_sensor_writel(temp_sensor, val,
+ temp_sensor->registers->bgap_mask_ctrl);
+
+ return 0;
+
+req_irq_err:
+ kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
+ sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
+ &omap_temp_sensor_group);
+sysfs_create_err:
+ hwmon_device_unregister(&pdev->dev);
+hwmon_reg_err:
+ omap_temp_sensor_clk_disable(temp_sensor);
+clken_err:
+ clk_put(temp_sensor->clock);
+plat_res_err:
+ dev_set_drvdata(&pdev->dev, NULL);
+ mutex_destroy(&temp_sensor->sensor_mutex);
+ kfree(temp_sensor);
+ return ret;
+}
+
+static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
+{
+ struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
+
+ hwmon_device_unregister(&pdev->dev);
+ kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
+ sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
+ &omap_temp_sensor_group);
+ omap_temp_sensor_clk_disable(temp_sensor);
+ free_irq(temp_sensor->irq, temp_sensor);
+ clk_put(temp_sensor->clock);
+ dev_set_drvdata(&pdev->dev, NULL);
+ mutex_destroy(&temp_sensor->sensor_mutex);
+ kfree(temp_sensor);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static void omap_temp_sensor_save_ctxt(struct omap_temp_sensor *temp_sensor)
+{
+ temp_sensor->temp_sensor_ctrl = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->temp_sensor_ctrl);
+ temp_sensor->bg_ctrl = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_mask_ctrl);
+ temp_sensor->bg_counter = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_counter);
+ temp_sensor->bg_threshold = omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->bgap_threshold);
+ temp_sensor->temp_sensor_tshut_threshold =
+ omap_temp_sensor_readl(temp_sensor,
+ temp_sensor->registers->thsut_threshold);
+}
+
+static void omap_temp_sensor_restore_ctxt(struct omap_temp_sensor *temp_sensor)
+{
+ omap_temp_sensor_writel(temp_sensor,
+ temp_sensor->temp_sensor_ctrl,
+ temp_sensor->registers->temp_sensor_ctrl);
+ omap_temp_sensor_writel(temp_sensor,
+ temp_sensor->bg_ctrl,
+ temp_sensor->registers->bgap_mask_ctrl);
+ omap_temp_sensor_writel(temp_sensor,
+ temp_sensor->bg_counter,
+ temp_sensor->registers->bgap_counter);
+ omap_temp_sensor_writel(temp_sensor,
+ temp_sensor->bg_threshold,
+ temp_sensor->registers->bgap_threshold);
+ omap_temp_sensor_writel(temp_sensor,
+ temp_sensor->temp_sensor_tshut_threshold,
+ temp_sensor->registers->thsut_threshold);
+}
+
+static int omap_temp_sensor_suspend(struct device *dev)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+
+ omap_temp_sensor_save_ctxt(temp_sensor);
+
+ return 0;
+}
+
+static int omap_temp_sensor_resume(struct device *dev)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+
+ omap_temp_sensor_restore_ctxt(temp_sensor);
+
+ return 0;
+}
+
+static int omap_temp_sensor_runtime_suspend(struct device *dev)
+{
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+
+ omap_temp_sensor_save_ctxt(temp_sensor);
+
+ return 0;
+}
+
+static int omap_temp_sensor_runtime_resume(struct device *dev)
+{
+ static int context_loss_count;
+ int temp;
+ struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
+
+ temp = omap_device_get_context_loss_count(to_platform_device(dev));
+
+ if (temp != context_loss_count && context_loss_count != 0)
+ omap_temp_sensor_restore_ctxt(temp_sensor);
+
+ context_loss_count = temp;
+
+ return 0;
+}
+
+static int omap_temp_sensor_idle(struct device *dev)
+{
+ return 0;
+}
+
+static const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(omap_temp_sensor_suspend,
+ omap_temp_sensor_resume)
+ SET_RUNTIME_PM_OPS(omap_temp_sensor_runtime_suspend,
+ omap_temp_sensor_runtime_resume, omap_temp_sensor_idle)
+};
+
+#define DEV_PM_OPS (&omap_temp_sensor_dev_pm_ops)
+#else
+#define DEV_PM_OPS NULL
+#endif
+
+static struct platform_driver omap_temp_sensor_driver = {
+ .probe = omap_temp_sensor_probe,
+ .remove = omap_temp_sensor_remove,
+ .driver = {
+ .name = "omap_temp_sensor",
+ .pm = DEV_PM_OPS,
+ },
+};
+
+int __init omap_temp_sensor_init(void)
+{
+ return platform_driver_register(&omap_temp_sensor_driver);
+}
+module_init(omap_temp_sensor_init);
+
+static void __exit omap_temp_sensor_exit(void)
+{
+ platform_driver_unregister(&omap_temp_sensor_driver);
+}
+module_exit(omap_temp_sensor_exit);
+
+MODULE_DESCRIPTION("OMAP446X temperature sensor Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
--
1.7.0.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 14:37 ` [PATCH 6/6 V3] hwmon: OMAP4: On die temperature " Keerthy
@ 2011-08-24 16:36 ` Janakiram Sistla
2011-08-24 18:18 ` J, KEERTHY
2011-08-25 7:24 ` Todd Poynor
1 sibling, 1 reply; 19+ messages in thread
From: Janakiram Sistla @ 2011-08-24 16:36 UTC (permalink / raw)
To: Keerthy; +Cc: linux-omap, lm-sensors
[-- Attachment #1.1: Type: text/plain, Size: 41314 bytes --]
Hi Keerthy,
Can you please point me the TRM of 4430 or 4460 where it reads the on die
temperature sensor used is TMP103. I am referring to public TRM on TI site.
Regards,
Sistla.
On Wed, Aug 24, 2011 at 9:37 AM, Keerthy <j-keerthy@ti.com> wrote:
> On chip temperature sensor driver. The driver monitors the temperature of
> the MPU subsystem of the OMAP4. It sends notifications to the user space if
> the temperature crosses user defined thresholds via kobject_uevent
> interface.
> The user is allowed to configure the temperature thresholds vis sysfs nodes
> exposed using hwmon interface.
>
> Signed-off-by: Keerthy <j-keerthy@ti.com>
> Cc: Jean Delvare <khali@linux-fr.org>
> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
> Cc: lm-sensors@lm-sensors.org
> ---
> Documentation/hwmon/omap_temp_sensor | 27 +
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/omap_temp_sensor.c | 933
> ++++++++++++++++++++++++++++++++++
> 4 files changed, 972 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/hwmon/omap_temp_sensor
> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>
> diff --git a/Documentation/hwmon/omap_temp_sensor
> b/Documentation/hwmon/omap_temp_sensor
> new file mode 100644
> index 0000000..e01a6d6
> --- /dev/null
> +++ b/Documentation/hwmon/omap_temp_sensor
> @@ -0,0 +1,27 @@
> +Kernel driver omap_temp_sensor
> +==============================
> +
> +Supported chips:
> + * Texas Instruments OMAP4460
> + Prefix: 'omap_temp_sensor'
> + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
> +
> +Author:
> + J Keerthy <j-keerthy@ti.com>
> +
> +Description
> +-----------
> +
> +The Texas Instruments OMAP4 family of chips have a bandgap temperature
> sensor.
> +The temperature sensor feature is used to convert the temperature of the
> device
> +into a decimal value coded on 10 bits. An internal ADC is used for
> conversion.
> +The recommended operating temperatures must be in the range -40 degree
> Celsius
> +to 123 degree celsius for standard conversion.
> +The thresholds are programmable and upon crossing the thresholds an
> interrupt
> +is generated. The OMAP temperature sensor has a programmable update rate
> in
> +milli seconds.
> +(Currently the driver programs a default of 2000 milli seconds).
> +
> +The driver provides the common sysfs-interface for temperatures (see
> +Documentation/hwmon/sysfs-interface under Temperatures).
> +
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 5f888f7..9c9cd8b 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -323,6 +323,17 @@ config SENSORS_F71805F
> This driver can also be built as a module. If so, the module
> will be called f71805f.
>
> +config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
> + bool "OMAP on-die temperature sensor hwmon driver"
> + depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
> + help
> + If you say yes here you get support for hardware
> + monitoring features of the OMAP on die temperature
> + sensor.
> +
> + Continuous conversion programmable delay
> + mode is used for temperature conversion.
> +
> config SENSORS_F71882FG
> tristate "Fintek F71882FG and compatibles"
> help
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 28061cf..d0f89f5 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> +obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
> diff --git a/drivers/hwmon/omap_temp_sensor.c
> b/drivers/hwmon/omap_temp_sensor.c
> new file mode 100644
> index 0000000..66fb3a9
> --- /dev/null
> +++ b/drivers/hwmon/omap_temp_sensor.c
> @@ -0,0 +1,933 @@
> +/*
> + * OMAP4 Temperature sensor driver file
> + *
> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
> + * Author: J Keerthy <j-keerthy@ti.com>
> + * Author: Moiz Sonasath <m-sonasath@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <plat/omap_device.h>
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/jiffies.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/stddef.h>
> +#include <linux/sysfs.h>
> +#include <linux/err.h>
> +#include <linux/types.h>
> +#include <linux/mutex.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/delay.h>
> +#include <plat/temperature_sensor.h>
> +
> +#define TSHUT_HOT 920 /* 122 deg C */
> +#define TSHUT_COLD 866 /* 100 deg C */
> +#define T_HOT 800 /* 73 deg C */
> +#define T_COLD 795 /* 71 deg C */
> +#define OMAP_ADC_START_VALUE 530
> +#define OMAP_ADC_END_VALUE 923
> +#define MAX_FREQ 2000000
> +#define MIN_FREQ 1000000
> +
> +/*
> + * omap_temp_sensor structure
> + * @hwmon_dev - device pointer
> + * @clock - Clock pointer
> + * @registers - Pointer to structure with register offsets and bitfields
> + * @sensor_mutex - Mutex for sysfs, irq and PM
> + * @irq - MPU Irq number for thermal alert
> + * @phy_base - Physical base of the temp I/O
> + * @clk_rate - Holds current clock rate
> + * @temp_sensor_ctrl - temp sensor control register value
> + * @bg_ctrl - bandgap ctrl register value
> + * @bg_counter - bandgap counter value
> + * @bg_threshold - bandgap threshold register value
> + * @temp_sensor_tshut_threshold - bandgap tshut register value
> + * @is_efuse_valid - Flag to determine if efuse is valid or not
> + * @clk_on - Manages the current clock state
> + */
> +struct omap_temp_sensor {
> + struct device *hwmon_dev;
> + struct clk *clock;
> + struct omap_temp_sensor_registers *registers;
> + struct mutex sensor_mutex; /* Mutex for sysfs, irq and
> PM */
> + unsigned int irq;
> + void __iomem *phy_base;
> + u32 clk_rate;
> + u32 temp_sensor_ctrl;
> + u32 bg_ctrl;
> + u32 bg_counter;
> + u32 bg_threshold;
> + u32 temp_sensor_tshut_threshold;
> + bool is_efuse_valid;
> + bool clk_on;
> +};
> +
> +/*
> + * Temperature values in milli degree celsius
> + * ADC code values from 530 to 923
> + */
> +static int adc_to_temp[] = {
> + -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600,
> -38200,
> + -37800, -37300, -36800, -36400, -36000, -35600, -35200, -34800,
> + -34300, -33800, -33400, -33000, -32600, -32200, -31800, -31300,
> + -30800, -30400, -30000, -29600, -29200, -28700, -28200, -27800,
> + -27400, -27000, -26600, -26200, -25700, -25200, -24800, -24400,
> + -24000, -23600, -23200, -22700, -22200, -21800, -21400, -21000,
> + -20600, -20200, -19700, -19200, -18800, -18400, -18000, -17600,
> + -17200, -16700, -16200, -15800, -15400, -15000, -14600, -14200,
> + -13700, -13200, -12800, -12400, -12000, -11600, -11200, -10700,
> + -10200, -9800, -9400, -9000, -8600, -8200, -7700, -7200, -6800,
> + -6400, -6000, -5600, -5200, -4800, -4300, -3800, -3400, -3000,
> + -2600, -2200, -1800, -1300, -800, -400, 0, 400, 800, 1200, 1600,
> + 2100, 2600, 3000, 3400, 3800, 4200, 4600, 5100, 5600, 6000, 6400,
> + 6800, 7200, 7600, 8000, 8500, 9000, 9400, 9800, 10200, 10600,
> 11000,
> + 11400, 11900, 12400, 12800, 13200, 13600, 14000, 14400, 14800,
> + 15300, 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18700,
> + 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22100, 22600,
> + 23000, 23400, 23800, 24200, 24600, 25000, 25400, 25900, 26400,
> + 26800, 27200, 27600, 28000, 28400, 28800, 29300, 29800, 30200,
> + 30600, 31000, 31400, 31800, 32200, 32600, 33100, 33600, 34000,
> + 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37300, 37800,
> + 38200, 38600, 39000, 39400, 39800, 40200, 40600, 41100, 41600,
> + 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45300,
> + 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 49000,
> + 49500, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800,
> + 53200, 53700, 54200, 54600, 55000, 55400, 55800, 56200, 56600,
> + 57000, 57400, 57800, 58200, 58700, 59200, 59600, 60000, 60400,
> + 60800, 61200, 61600, 62000, 62400, 62800, 63300, 63800, 64200,
> + 64600, 65000, 65400, 65800, 66200, 66600, 67000, 67400, 67800,
> + 68200, 68700, 69200, 69600, 70000, 70400, 70800, 71200, 71600,
> + 72000, 72400, 72800, 73200, 73600, 74100, 74600, 75000, 75400,
> + 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600, 79000,
> + 79400, 79800, 80300, 80800, 81200, 81600, 82000, 82400, 82800,
> + 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400,
> + 86800, 87300, 87800, 88200, 88600, 89000, 89400, 89800, 90200,
> + 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 93800,
> + 94200, 94600, 95000, 95500, 96000, 96400, 96800, 97200, 97600,
> + 98000, 98400, 98800, 99200, 99600, 100000, 100400, 100800, 101200,
> + 101600, 102000, 102400, 102800, 103200, 103600, 104000, 104400,
> + 104800, 105200, 105600, 106100, 106600, 107000, 107400, 107800,
> + 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
> + 111400, 111800, 112200, 112600, 113000, 113400, 113800, 114200,
> + 114600, 115000, 115400, 115800, 116200, 116600, 117000, 117400,
> + 117800, 118200, 118600, 119000, 119400, 119800, 120200, 120600,
> + 121000, 121400, 121800, 122200, 122600, 123000
> +};
> +
> +static unsigned long omap_temp_sensor_readl(struct omap_temp_sensor
> + *temp_sensor, u32 reg)
> +{
> + return __raw_readl(temp_sensor->phy_base + reg);
> +}
> +
> +static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
> + u32 val, u32 reg)
> +{
> + __raw_writel(val, (temp_sensor->phy_base + reg));
> +}
> +
> +static int adc_to_temp_conversion(int adc_val)
> +{
> + return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
> +}
> +
> +static int temp_to_adc_conversion(long temp)
> +{
> + int high, low, mid;
> +
> + if (temp < adc_to_temp[0] ||
> + temp > adc_to_temp[OMAP_ADC_END_VALUE -
> OMAP_ADC_START_VALUE])
> + return -EINVAL;
> +
> + high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
> + low = 0;
> + mid = (high + low) / 2;
> +
> + while (low < high) {
> + if (temp < adc_to_temp[mid])
> + high = mid - 1;
> + else
> + low = mid + 1;
> + mid = (low + high) / 2;
> + }
> +
> + return OMAP_ADC_START_VALUE + low;
> +}
> +
> +static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
> + *temp_sensor)
> +{
> + u32 temp;
> +
> + /* Configure the TALERT thresholds */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp |= (T_HOT <<
> __ffs(temp_sensor->registers->threshold_thot_mask)) |
> + (T_COLD <<
> __ffs(temp_sensor->registers->threshold_tcold_mask));
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Configure the TSHUT thresholds */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->thsut_threshold);
> + temp |= (TSHUT_HOT <<
> __ffs(temp_sensor->registers->tshut_hot_mask))
> + | (TSHUT_COLD <<
> __ffs(temp_sensor->registers->tshut_hot_mask));
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static void omap_configure_temp_sensor_counter(struct omap_temp_sensor
> + *temp_sensor, u32 counter)
> +{
> + u32 val;
> +
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + val &= ~temp_sensor->registers->counter_mask;
> + val |= counter << __ffs(temp_sensor->registers->counter_mask);
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_counter);
> +}
> +
> +static void omap_enable_continuous_mode(struct omap_temp_sensor
> *temp_sensor,
> + bool enable)
> +{
> + u32 val;
> +
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mode_ctrl);
> +
> + if (enable)
> + val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
> + else
> + val &= ~temp_sensor->registers->mode_ctrl_mask;
> +
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_mode_ctrl);
> +}
> +
> +/* Sysfs hook functions */
> +
> +static ssize_t show_temp_max(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + int temp;
> +
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
> + >>
> __ffs(temp_sensor->registers->threshold_thot_mask);
> +
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid value\n");
> + return -EDOM;
> + }
> +
> + temp = adc_to_temp_conversion(temp);
> +
> + return snprintf(buf, 16, "%d\n", temp);
> +}
> +
> +static ssize_t set_temp_max(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + long val;
> + u32 reg_val, t_cold, t_hot, temp;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + t_hot = temp_to_adc_conversion(val);
> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + /* obtain the T cold value */
> + t_cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask) >>
> +
> __ffs(temp_sensor->registers->threshold_tcold_mask);
> +
> + if (t_hot < t_cold) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + /* write the new t_hot value */
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
> + reg_val |= (t_hot <<
> +
> __ffs(temp_sensor->registers->threshold_thot_mask));
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Read the current temperature */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /*
> + * If user sets the HIGH threshold(t_hot) greater than the current
> + * temperature(temp) unmask the HOT interrupts
> + */
> + if (t_hot > temp) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * If current temperature is in-between the hot and cold
> thresholds,
> + * Enable both masks.
> + */
> + if (temp > t_cold && temp < t_hot) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + OMAP4460_BGAP_CTRL_OFFSET);
> + }
> + /*
> + * else no need to do anything since HW will immediately compare
> + * the new threshold and generate interrupt accordingly
> + */
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return count;
> +}
> +
> +static ssize_t show_temp_max_hyst(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 temp;
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid value\n");
> + return -EDOM;
> + }
> +
> + temp = adc_to_temp_conversion(temp);
> +
> + return snprintf(buf, 16, "%d\n", temp);
> +}
> +
> +static ssize_t set_temp_max_hyst(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor =
> dev_get_drvdata(dev);
> + u32 reg_val, t_hot, t_cold, temp;
> + long val;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + t_cold = temp_to_adc_conversion(val);
> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + /* obtain the T HOT value */
> + t_hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
> + __ffs(temp_sensor->registers->threshold_thot_mask);
> +
> + if (t_cold > t_hot) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + /* write the new t_cold value */
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
> + reg_val |= t_cold <<
> +
> __ffs(temp_sensor->registers->threshold_tcold_mask);
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> +
> + /* Read the current temperature */
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /*
> + * If user sets the LOW threshold(t_cold) lower than the current
> + * temperature(temp) unmask the COLD interrupts
> + */
> + if (t_cold < temp) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * If current temperature is in-between the hot and cold
> thresholds,
> + * Enable both masks.
> + */
> + if (temp < t_hot && temp > t_cold) {
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> + }
> +
> + /*
> + * else no need to do anything since HW will immediately compare
> + * the new threshold and generate interrupt accordingly
> + */
> +
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return count;
> +}
> +
> +static ssize_t show_update_rate(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 temp = 0, ret = 0;
> +
> +
> + if (!temp_sensor->clk_rate) {
> + dev_err(dev, "clk_rate is NULL\n");
> + ret = -EDOM;
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + temp = (temp & temp_sensor->registers->counter_mask) >>
> + __ffs(temp_sensor->registers->counter_mask);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> + temp = temp * 1000 / temp_sensor->clk_rate;
> +
> +out:
> + if (!ret)
> + return sprintf(buf, "%d\n", temp);
> +
> + return ret;
> +}
> +
> +static ssize_t set_update_rate(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 reg_val;
> + long val;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
> +
> + val *= temp_sensor->clk_rate / 1000;
> + mutex_lock(&temp_sensor->sensor_mutex);
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> +
> + reg_val &= ~temp_sensor->registers->counter_mask;
> + reg_val |= val;
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_counter);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +out:
> + return count;
> +}
> +
> +static int omap_temp_sensor_read_temp(struct device *dev,
> + struct device_attribute *devattr,
> + char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + int temp, ret = 0;
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp &= temp_sensor->registers->bgap_dtemp_mask;
> +
> + /* look up for temperature in the table and return the temperature
> */
> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> + dev_err(dev, "invalid adc code reported %d", temp);
> + ret = -EDOM;
> + goto out;
> + }
> +
> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
> +
> +out:
> + mutex_unlock(&temp_sensor->sensor_mutex);
> + if (!ret)
> + return sprintf(buf, "%d\n", temp);
> +
> + return ret;
> +}
> +
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
> omap_temp_sensor_read_temp,
> + NULL, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
> + set_temp_max, 0);
> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
> show_temp_max_hyst,
> + set_temp_max_hyst, 0);
> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO,
> show_update_rate,
> + set_update_rate, 0);
> +
> +static struct attribute *omap_temp_sensor_attributes[] = {
> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> + &sensor_dev_attr_temp1_max.dev_attr.attr,
> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
> + &sensor_dev_attr_update_rate.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group omap_temp_sensor_group = {
> + .attrs = omap_temp_sensor_attributes,
> +};
> +
> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor
> *temp_sensor)
> +{
> + u32 ret = 0;
> +
> + if (temp_sensor->clk_on) {
> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
> + goto out;
> + }
> +
> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
> + if (ret < 0) {
> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp_sensor->clk_on = 1;
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +out:
> + return ret;
> +}
> +
> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor
> *temp_sensor)
> +{
> + u32 ret = 0;
> +
> + if (!temp_sensor->clk_on) {
> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
> + goto out;
> + }
> +
> + /* Gate the clock */
> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
> + if (ret < 0) {
> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
> + goto out;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + temp_sensor->clk_on = 0;
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +out:
> + return ret;
> +}
> +
> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
> +{
> + struct omap_temp_sensor *temp_sensor;
> + int t_hot, t_cold, temp;
> +
> + temp_sensor = data;
> + mutex_lock(&temp_sensor->sensor_mutex);
> +
> + /* Read the status of t_hot */
> + t_hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_status)
> + & temp_sensor->registers->status_hot_mask;
> +
> + /* Read the status of t_cold */
> + t_cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_status)
> + & temp_sensor->registers->status_cold_mask;
> +
> + temp = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + /*
> + * One TALERT interrupt: Two sources
> + * If the interrupt is due to t_hot then mask t_hot and
> + * and unmask t_cold else mask t_cold and unmask t_hot
> + */
> + if (t_hot) {
> + temp &= ~temp_sensor->registers->mask_hot_mask;
> + temp |= temp_sensor->registers->mask_cold_mask;
> + } else if (t_cold) {
> + temp &= ~temp_sensor->registers->mask_cold_mask;
> + temp |= temp_sensor->registers->mask_hot_mask;
> + }
> +
> + omap_temp_sensor_writel(temp_sensor, temp,
> + temp_sensor->registers->bgap_mask_ctrl);
> +
> + /* kobject_uvent to user space telling thermal threshold crossed */
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
> +
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
> +{
> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
> + struct omap_temp_sensor *temp_sensor;
> + struct resource *mem;
> + int ret = 0;
> + int val, clk_rate;
> + u32 max_freq, min_freq;
> +
> + if (!pdata) {
> + dev_err(&pdev->dev, "platform data missing\n");
> + return -EINVAL;
> + }
> +
> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
> + if (!temp_sensor)
> + return -ENOMEM;
> +
> + mutex_init(&temp_sensor->sensor_mutex);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&pdev->dev, "no mem resource\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> + if (temp_sensor->irq < 0) {
> + dev_err(&pdev->dev, "get_irq_byname failed\n");
> + ret = temp_sensor->irq;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
> + temp_sensor->clock = NULL;
> + temp_sensor->registers = pdata->registers;
> + temp_sensor->hwmon_dev = &pdev->dev;
> +
> + if (pdata->max_freq && pdata->min_freq) {
> + max_freq = pdata->max_freq;
> + min_freq = pdata->min_freq;
> + } else {
> + max_freq = MAX_FREQ;
> + min_freq = MIN_FREQ;
> + }
> +
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_irq_safe(&pdev->dev);
> +
> + /*
> + * check if the efuse has a non-zero value if not
> + * it is an untrimmed sample and the temperatures
> + * may not be accurate
> + */
> +
> + if (omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_efuse)) {
> + temp_sensor->is_efuse_valid = 1;
> + dev_dbg(temp_sensor->hwmon_dev,
> + "Invalid EFUSE, Non-trimmed BGAP, Temp not
> accurate\n");
> + }
> +
> + dev_set_drvdata(&pdev->dev, temp_sensor);
> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
> + if (IS_ERR(temp_sensor->clock)) {
> + ret = PTR_ERR(temp_sensor->clock);
> + dev_err(temp_sensor->hwmon_dev,
> + "unable to get fclk: %d\n", ret);
> + goto plat_res_err;
> + }
> +
> + ret = omap_temp_sensor_clk_enable(temp_sensor);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
> + goto clken_err;
> + }
> +
> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
> + dev_err(&pdev->dev, "Error round rate\n");
> + ret = -EDOM;
> + goto clken_err;
> + }
> +
> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot set clock rate\n");
> + goto clken_err;
> + }
> +
> + temp_sensor->clk_rate = clk_rate;
> + omap_enable_continuous_mode(temp_sensor, 1);
> + omap_configure_temp_sensor_thresholds(temp_sensor);
> + /* 1 ms */
> + omap_configure_temp_sensor_counter(temp_sensor, 1);
> +
> + /* Wait till the first conversion is done wait for at least 1ms */
> + usleep_range(1000, 2000);
> +
> + /* Read the temperature once due to hw issue*/
> + omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> +
> + /* Set 2 seconds time as default counter */
> + omap_configure_temp_sensor_counter(temp_sensor,
> + temp_sensor->clk_rate * 2);
> +
> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
> + if (IS_ERR(temp_sensor->hwmon_dev)) {
> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
> + ret = PTR_ERR(temp_sensor->hwmon_dev);
> + goto hwmon_reg_err;
> + }
> +
> + ret = sysfs_create_group(&pdev->dev.kobj,
> + &omap_temp_sensor_group);
> + if (ret) {
> + dev_err(&pdev->dev, "could not create sysfs files\n");
> + goto sysfs_create_err;
> + }
> +
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
> +
> + ret = request_threaded_irq(temp_sensor->irq, NULL,
> + omap_talert_irq_handler, IRQF_TRIGGER_RISING |
> IRQF_ONESHOT,
> + "temp_sensor", temp_sensor);
> + if (ret) {
> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
> + goto req_irq_err;
> + }
> +
> + /* unmask the T_COLD and unmask T_HOT at init */
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + val |= temp_sensor->registers->mask_cold_mask
> + | temp_sensor->registers->mask_hot_mask;
> +
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_mask_ctrl);
> +
> + return 0;
> +
> +req_irq_err:
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> +sysfs_create_err:
> + hwmon_device_unregister(&pdev->dev);
> +hwmon_reg_err:
> + omap_temp_sensor_clk_disable(temp_sensor);
> +clken_err:
> + clk_put(temp_sensor->clock);
> +plat_res_err:
> + dev_set_drvdata(&pdev->dev, NULL);
> + mutex_destroy(&temp_sensor->sensor_mutex);
> + kfree(temp_sensor);
> + return ret;
> +}
> +
> +static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
> +{
> + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
> +
> + hwmon_device_unregister(&pdev->dev);
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> + omap_temp_sensor_clk_disable(temp_sensor);
> + free_irq(temp_sensor->irq, temp_sensor);
> + clk_put(temp_sensor->clock);
> + dev_set_drvdata(&pdev->dev, NULL);
> + mutex_destroy(&temp_sensor->sensor_mutex);
> + kfree(temp_sensor);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static void omap_temp_sensor_save_ctxt(struct omap_temp_sensor
> *temp_sensor)
> +{
> + temp_sensor->temp_sensor_ctrl = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->temp_sensor_ctrl);
> + temp_sensor->bg_ctrl = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + temp_sensor->bg_counter = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_counter);
> + temp_sensor->bg_threshold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + temp_sensor->temp_sensor_tshut_threshold =
> + omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static void omap_temp_sensor_restore_ctxt(struct omap_temp_sensor
> *temp_sensor)
> +{
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->temp_sensor_ctrl,
> + temp_sensor->registers->temp_sensor_ctrl);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_ctrl,
> + temp_sensor->registers->bgap_mask_ctrl);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_counter,
> + temp_sensor->registers->bgap_counter);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->bg_threshold,
> + temp_sensor->registers->bgap_threshold);
> + omap_temp_sensor_writel(temp_sensor,
> + temp_sensor->temp_sensor_tshut_threshold,
> + temp_sensor->registers->thsut_threshold);
> +}
> +
> +static int omap_temp_sensor_suspend(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_save_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_resume(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_restore_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_runtime_suspend(struct device *dev)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + omap_temp_sensor_save_ctxt(temp_sensor);
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_runtime_resume(struct device *dev)
> +{
> + static int context_loss_count;
> + int temp;
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> +
> + temp = omap_device_get_context_loss_count(to_platform_device(dev));
> +
> + if (temp != context_loss_count && context_loss_count != 0)
> + omap_temp_sensor_restore_ctxt(temp_sensor);
> +
> + context_loss_count = temp;
> +
> + return 0;
> +}
> +
> +static int omap_temp_sensor_idle(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(omap_temp_sensor_suspend,
> + omap_temp_sensor_resume)
> + SET_RUNTIME_PM_OPS(omap_temp_sensor_runtime_suspend,
> + omap_temp_sensor_runtime_resume,
> omap_temp_sensor_idle)
> +};
> +
> +#define DEV_PM_OPS (&omap_temp_sensor_dev_pm_ops)
> +#else
> +#define DEV_PM_OPS NULL
> +#endif
> +
> +static struct platform_driver omap_temp_sensor_driver = {
> + .probe = omap_temp_sensor_probe,
> + .remove = omap_temp_sensor_remove,
> + .driver = {
> + .name = "omap_temp_sensor",
> + .pm = DEV_PM_OPS,
> + },
> +};
> +
> +int __init omap_temp_sensor_init(void)
> +{
> + return platform_driver_register(&omap_temp_sensor_driver);
> +}
> +module_init(omap_temp_sensor_init);
> +
> +static void __exit omap_temp_sensor_exit(void)
> +{
> + platform_driver_unregister(&omap_temp_sensor_driver);
> +}
> +module_exit(omap_temp_sensor_exit);
> +
> +MODULE_DESCRIPTION("OMAP446X temperature sensor Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> +MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
> --
> 1.7.0.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Thanks and Regards,
Janakiram Sistla.
[-- Attachment #1.2: Type: text/html, Size: 47172 bytes --]
[-- Attachment #2: Type: text/plain, Size: 153 bytes --]
_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 16:36 ` Janakiram Sistla
@ 2011-08-24 18:18 ` J, KEERTHY
2011-08-24 19:52 ` Janakiram Sistla
0 siblings, 1 reply; 19+ messages in thread
From: J, KEERTHY @ 2011-08-24 18:18 UTC (permalink / raw)
To: Janakiram Sistla; +Cc: linux-omap, Jean Delvare, Guenter Roeck, lm-sensors
On Wed, Aug 24, 2011 at 10:06 PM, Janakiram Sistla
<janakiram.sistla@gmail.com> wrote:
> Hi Keerthy,
>
> Can you please point me the TRM of 4430 or 4460 where it reads the on die
> temperature sensor used is TMP103. I am referring to public TRM on TI site.
Sorry my bad! I shall remove that.
>
> Regards,
> Sistla.
>
> On Wed, Aug 24, 2011 at 9:37 AM, Keerthy <j-keerthy@ti.com> wrote:
>>
>> On chip temperature sensor driver. The driver monitors the temperature of
>> the MPU subsystem of the OMAP4. It sends notifications to the user space
>> if
>> the temperature crosses user defined thresholds via kobject_uevent
>> interface.
>> The user is allowed to configure the temperature thresholds vis sysfs
>> nodes
>> exposed using hwmon interface.
>>
>> Signed-off-by: Keerthy <j-keerthy@ti.com>
>> Cc: Jean Delvare <khali@linux-fr.org>
>> Cc: Guenter Roeck <guenter.roeck@ericsson.com>
>> Cc: lm-sensors@lm-sensors.org
>> ---
>> Documentation/hwmon/omap_temp_sensor | 27 +
>> drivers/hwmon/Kconfig | 11 +
>> drivers/hwmon/Makefile | 1 +
>> drivers/hwmon/omap_temp_sensor.c | 933
>> ++++++++++++++++++++++++++++++++++
>> 4 files changed, 972 insertions(+), 0 deletions(-)
>> create mode 100644 Documentation/hwmon/omap_temp_sensor
>> create mode 100644 drivers/hwmon/omap_temp_sensor.c
>>
>> diff --git a/Documentation/hwmon/omap_temp_sensor
>> b/Documentation/hwmon/omap_temp_sensor
>> new file mode 100644
>> index 0000000..e01a6d6
>> --- /dev/null
>> +++ b/Documentation/hwmon/omap_temp_sensor
>> @@ -0,0 +1,27 @@
>> +Kernel driver omap_temp_sensor
>> +==============================
>> +
>> +Supported chips:
>> + * Texas Instruments OMAP4460
>> + Prefix: 'omap_temp_sensor'
>> + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html
>> +
>> +Author:
>> + J Keerthy <j-keerthy@ti.com>
>> +
>> +Description
>> +-----------
>> +
>> +The Texas Instruments OMAP4 family of chips have a bandgap temperature
>> sensor.
>> +The temperature sensor feature is used to convert the temperature of the
>> device
>> +into a decimal value coded on 10 bits. An internal ADC is used for
>> conversion.
>> +The recommended operating temperatures must be in the range -40 degree
>> Celsius
>> +to 123 degree celsius for standard conversion.
>> +The thresholds are programmable and upon crossing the thresholds an
>> interrupt
>> +is generated. The OMAP temperature sensor has a programmable update rate
>> in
>> +milli seconds.
>> +(Currently the driver programs a default of 2000 milli seconds).
>> +
>> +The driver provides the common sysfs-interface for temperatures (see
>> +Documentation/hwmon/sysfs-interface under Temperatures).
>> +
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 5f888f7..9c9cd8b 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -323,6 +323,17 @@ config SENSORS_F71805F
>> This driver can also be built as a module. If so, the module
>> will be called f71805f.
>>
>> +config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
>> + bool "OMAP on-die temperature sensor hwmon driver"
>> + depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
>> + help
>> + If you say yes here you get support for hardware
>> + monitoring features of the OMAP on die temperature
>> + sensor.
>> +
>> + Continuous conversion programmable delay
>> + mode is used for temperature conversion.
>> +
>> config SENSORS_F71882FG
>> tristate "Fintek F71882FG and compatibles"
>> help
>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>> index 28061cf..d0f89f5 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
>> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
>> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
>> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
>> +obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
>> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
>> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
>> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
>> diff --git a/drivers/hwmon/omap_temp_sensor.c
>> b/drivers/hwmon/omap_temp_sensor.c
>> new file mode 100644
>> index 0000000..66fb3a9
>> --- /dev/null
>> +++ b/drivers/hwmon/omap_temp_sensor.c
>> @@ -0,0 +1,933 @@
>> +/*
>> + * OMAP4 Temperature sensor driver file
>> + *
>> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
>> + * Author: J Keerthy <j-keerthy@ti.com>
>> + * Author: Moiz Sonasath <m-sonasath@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful, but
>> + * WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
>> + * 02110-1301 USA
>> + *
>> + */
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/clk.h>
>> +#include <linux/io.h>
>> +#include <linux/slab.h>
>> +#include <linux/init.h>
>> +#include <plat/omap_device.h>
>> +#include <linux/kernel.h>
>> +#include <linux/device.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/stddef.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/err.h>
>> +#include <linux/types.h>
>> +#include <linux/mutex.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/delay.h>
>> +#include <plat/temperature_sensor.h>
>> +
>> +#define TSHUT_HOT 920 /* 122 deg C */
>> +#define TSHUT_COLD 866 /* 100 deg C */
>> +#define T_HOT 800 /* 73 deg C */
>> +#define T_COLD 795 /* 71 deg C */
>> +#define OMAP_ADC_START_VALUE 530
>> +#define OMAP_ADC_END_VALUE 923
>> +#define MAX_FREQ 2000000
>> +#define MIN_FREQ 1000000
>> +
>> +/*
>> + * omap_temp_sensor structure
>> + * @hwmon_dev - device pointer
>> + * @clock - Clock pointer
>> + * @registers - Pointer to structure with register offsets and bitfields
>> + * @sensor_mutex - Mutex for sysfs, irq and PM
>> + * @irq - MPU Irq number for thermal alert
>> + * @phy_base - Physical base of the temp I/O
>> + * @clk_rate - Holds current clock rate
>> + * @temp_sensor_ctrl - temp sensor control register value
>> + * @bg_ctrl - bandgap ctrl register value
>> + * @bg_counter - bandgap counter value
>> + * @bg_threshold - bandgap threshold register value
>> + * @temp_sensor_tshut_threshold - bandgap tshut register value
>> + * @is_efuse_valid - Flag to determine if efuse is valid or not
>> + * @clk_on - Manages the current clock state
>> + */
>> +struct omap_temp_sensor {
>> + struct device *hwmon_dev;
>> + struct clk *clock;
>> + struct omap_temp_sensor_registers *registers;
>> + struct mutex sensor_mutex; /* Mutex for sysfs, irq and
>> PM */
>> + unsigned int irq;
>> + void __iomem *phy_base;
>> + u32 clk_rate;
>> + u32 temp_sensor_ctrl;
>> + u32 bg_ctrl;
>> + u32 bg_counter;
>> + u32 bg_threshold;
>> + u32 temp_sensor_tshut_threshold;
>> + bool is_efuse_valid;
>> + bool clk_on;
>> +};
>> +
>> +/*
>> + * Temperature values in milli degree celsius
>> + * ADC code values from 530 to 923
>> + */
>> +static int adc_to_temp[] = {
>> + -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600,
>> -38200,
>> + -37800, -37300, -36800, -36400, -36000, -35600, -35200, -34800,
>> + -34300, -33800, -33400, -33000, -32600, -32200, -31800, -31300,
>> + -30800, -30400, -30000, -29600, -29200, -28700, -28200, -27800,
>> + -27400, -27000, -26600, -26200, -25700, -25200, -24800, -24400,
>> + -24000, -23600, -23200, -22700, -22200, -21800, -21400, -21000,
>> + -20600, -20200, -19700, -19200, -18800, -18400, -18000, -17600,
>> + -17200, -16700, -16200, -15800, -15400, -15000, -14600, -14200,
>> + -13700, -13200, -12800, -12400, -12000, -11600, -11200, -10700,
>> + -10200, -9800, -9400, -9000, -8600, -8200, -7700, -7200, -6800,
>> + -6400, -6000, -5600, -5200, -4800, -4300, -3800, -3400, -3000,
>> + -2600, -2200, -1800, -1300, -800, -400, 0, 400, 800, 1200, 1600,
>> + 2100, 2600, 3000, 3400, 3800, 4200, 4600, 5100, 5600, 6000, 6400,
>> + 6800, 7200, 7600, 8000, 8500, 9000, 9400, 9800, 10200, 10600,
>> 11000,
>> + 11400, 11900, 12400, 12800, 13200, 13600, 14000, 14400, 14800,
>> + 15300, 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18700,
>> + 19200, 19600, 20000, 20400, 20800, 21200, 21600, 22100, 22600,
>> + 23000, 23400, 23800, 24200, 24600, 25000, 25400, 25900, 26400,
>> + 26800, 27200, 27600, 28000, 28400, 28800, 29300, 29800, 30200,
>> + 30600, 31000, 31400, 31800, 32200, 32600, 33100, 33600, 34000,
>> + 34400, 34800, 35200, 35600, 36000, 36400, 36800, 37300, 37800,
>> + 38200, 38600, 39000, 39400, 39800, 40200, 40600, 41100, 41600,
>> + 42000, 42400, 42800, 43200, 43600, 44000, 44400, 44800, 45300,
>> + 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 49000,
>> + 49500, 50000, 50400, 50800, 51200, 51600, 52000, 52400, 52800,
>> + 53200, 53700, 54200, 54600, 55000, 55400, 55800, 56200, 56600,
>> + 57000, 57400, 57800, 58200, 58700, 59200, 59600, 60000, 60400,
>> + 60800, 61200, 61600, 62000, 62400, 62800, 63300, 63800, 64200,
>> + 64600, 65000, 65400, 65800, 66200, 66600, 67000, 67400, 67800,
>> + 68200, 68700, 69200, 69600, 70000, 70400, 70800, 71200, 71600,
>> + 72000, 72400, 72800, 73200, 73600, 74100, 74600, 75000, 75400,
>> + 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600, 79000,
>> + 79400, 79800, 80300, 80800, 81200, 81600, 82000, 82400, 82800,
>> + 83200, 83600, 84000, 84400, 84800, 85200, 85600, 86000, 86400,
>> + 86800, 87300, 87800, 88200, 88600, 89000, 89400, 89800, 90200,
>> + 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 93800,
>> + 94200, 94600, 95000, 95500, 96000, 96400, 96800, 97200, 97600,
>> + 98000, 98400, 98800, 99200, 99600, 100000, 100400, 100800, 101200,
>> + 101600, 102000, 102400, 102800, 103200, 103600, 104000, 104400,
>> + 104800, 105200, 105600, 106100, 106600, 107000, 107400, 107800,
>> + 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
>> + 111400, 111800, 112200, 112600, 113000, 113400, 113800, 114200,
>> + 114600, 115000, 115400, 115800, 116200, 116600, 117000, 117400,
>> + 117800, 118200, 118600, 119000, 119400, 119800, 120200, 120600,
>> + 121000, 121400, 121800, 122200, 122600, 123000
>> +};
>> +
>> +static unsigned long omap_temp_sensor_readl(struct omap_temp_sensor
>> + *temp_sensor, u32 reg)
>> +{
>> + return __raw_readl(temp_sensor->phy_base + reg);
>> +}
>> +
>> +static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
>> + u32 val, u32 reg)
>> +{
>> + __raw_writel(val, (temp_sensor->phy_base + reg));
>> +}
>> +
>> +static int adc_to_temp_conversion(int adc_val)
>> +{
>> + return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
>> +}
>> +
>> +static int temp_to_adc_conversion(long temp)
>> +{
>> + int high, low, mid;
>> +
>> + if (temp < adc_to_temp[0] ||
>> + temp > adc_to_temp[OMAP_ADC_END_VALUE -
>> OMAP_ADC_START_VALUE])
>> + return -EINVAL;
>> +
>> + high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
>> + low = 0;
>> + mid = (high + low) / 2;
>> +
>> + while (low < high) {
>> + if (temp < adc_to_temp[mid])
>> + high = mid - 1;
>> + else
>> + low = mid + 1;
>> + mid = (low + high) / 2;
>> + }
>> +
>> + return OMAP_ADC_START_VALUE + low;
>> +}
>> +
>> +static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
>> + *temp_sensor)
>> +{
>> + u32 temp;
>> +
>> + /* Configure the TALERT thresholds */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp |= (T_HOT <<
>> __ffs(temp_sensor->registers->threshold_thot_mask)) |
>> + (T_COLD <<
>> __ffs(temp_sensor->registers->threshold_tcold_mask));
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Configure the TSHUT thresholds */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->thsut_threshold);
>> + temp |= (TSHUT_HOT <<
>> __ffs(temp_sensor->registers->tshut_hot_mask))
>> + | (TSHUT_COLD <<
>> __ffs(temp_sensor->registers->tshut_hot_mask));
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static void omap_configure_temp_sensor_counter(struct omap_temp_sensor
>> + *temp_sensor, u32 counter)
>> +{
>> + u32 val;
>> +
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + val &= ~temp_sensor->registers->counter_mask;
>> + val |= counter << __ffs(temp_sensor->registers->counter_mask);
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_counter);
>> +}
>> +
>> +static void omap_enable_continuous_mode(struct omap_temp_sensor
>> *temp_sensor,
>> + bool enable)
>> +{
>> + u32 val;
>> +
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mode_ctrl);
>> +
>> + if (enable)
>> + val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
>> + else
>> + val &= ~temp_sensor->registers->mode_ctrl_mask;
>> +
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_mode_ctrl);
>> +}
>> +
>> +/* Sysfs hook functions */
>> +
>> +static ssize_t show_temp_max(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + int temp;
>> +
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp = (temp & temp_sensor->registers->threshold_thot_mask)
>> + >>
>> __ffs(temp_sensor->registers->threshold_thot_mask);
>> +
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid value\n");
>> + return -EDOM;
>> + }
>> +
>> + temp = adc_to_temp_conversion(temp);
>> +
>> + return snprintf(buf, 16, "%d\n", temp);
>> +}
>> +
>> +static ssize_t set_temp_max(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + long val;
>> + u32 reg_val, t_cold, t_hot, temp;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + t_hot = temp_to_adc_conversion(val);
>> + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE))
>> {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + /* obtain the T cold value */
>> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + t_cold = (t_cold & temp_sensor->registers->threshold_tcold_mask)
>> >>
>> +
>> __ffs(temp_sensor->registers->threshold_tcold_mask);
>> +
>> + if (t_hot < t_cold) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + /* write the new t_hot value */
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + reg_val &= ~temp_sensor->registers->threshold_thot_mask;
>> + reg_val |= (t_hot <<
>> +
>> __ffs(temp_sensor->registers->threshold_thot_mask));
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Read the current temperature */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /*
>> + * If user sets the HIGH threshold(t_hot) greater than the current
>> + * temperature(temp) unmask the HOT interrupts
>> + */
>> + if (t_hot > temp) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * If current temperature is in-between the hot and cold
>> thresholds,
>> + * Enable both masks.
>> + */
>> + if (temp > t_cold && temp < t_hot) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + OMAP4460_BGAP_CTRL_OFFSET);
>> + }
>> + /*
>> + * else no need to do anything since HW will immediately compare
>> + * the new threshold and generate interrupt accordingly
>> + */
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return count;
>> +}
>> +
>> +static ssize_t show_temp_max_hyst(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 temp;
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp = (temp & temp_sensor->registers->threshold_tcold_mask) >>
>> + __ffs(temp_sensor->registers->threshold_tcold_mask);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid value\n");
>> + return -EDOM;
>> + }
>> +
>> + temp = adc_to_temp_conversion(temp);
>> +
>> + return snprintf(buf, 16, "%d\n", temp);
>> +}
>> +
>> +static ssize_t set_temp_max_hyst(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor =
>> dev_get_drvdata(dev);
>> + u32 reg_val, t_hot, t_cold, temp;
>> + long val;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + t_cold = temp_to_adc_conversion(val);
>> + if (t_cold < OMAP_ADC_START_VALUE || t_cold > OMAP_ADC_END_VALUE)
>> {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + /* obtain the T HOT value */
>> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + t_hot = (t_hot & temp_sensor->registers->threshold_thot_mask) >>
>> +
>> __ffs(temp_sensor->registers->threshold_thot_mask);
>> +
>> + if (t_cold > t_hot) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + /* write the new t_cold value */
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + reg_val &= ~temp_sensor->registers->threshold_tcold_mask;
>> + reg_val |= t_cold <<
>> +
>> __ffs(temp_sensor->registers->threshold_tcold_mask);
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_threshold);
>> +
>> + /* Read the current temperature */
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /*
>> + * If user sets the LOW threshold(t_cold) lower than the current
>> + * temperature(temp) unmask the COLD interrupts
>> + */
>> + if (t_cold < temp) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * If current temperature is in-between the hot and cold
>> thresholds,
>> + * Enable both masks.
>> + */
>> + if (temp < t_hot && temp > t_cold) {
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + reg_val |= temp_sensor->registers->mask_cold_mask;
>> + reg_val |= temp_sensor->registers->mask_hot_mask;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + }
>> +
>> + /*
>> + * else no need to do anything since HW will immediately compare
>> + * the new threshold and generate interrupt accordingly
>> + */
>> +
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return count;
>> +}
>> +
>> +static ssize_t show_update_rate(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 temp = 0, ret = 0;
>> +
>> +
>> + if (!temp_sensor->clk_rate) {
>> + dev_err(dev, "clk_rate is NULL\n");
>> + ret = -EDOM;
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + temp = (temp & temp_sensor->registers->counter_mask) >>
>> + __ffs(temp_sensor->registers->counter_mask);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> + temp = temp * 1000 / temp_sensor->clk_rate;
>> +
>> +out:
>> + if (!ret)
>> + return sprintf(buf, "%d\n", temp);
>> +
>> + return ret;
>> +}
>> +
>> +static ssize_t set_update_rate(struct device *dev,
>> + struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + u32 reg_val;
>> + long val;
>> +
>> + if (strict_strtol(buf, 10, &val)) {
>> + count = -EINVAL;
>> + goto out;
>> + }
>> +
>> + val *= temp_sensor->clk_rate / 1000;
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + reg_val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> +
>> + reg_val &= ~temp_sensor->registers->counter_mask;
>> + reg_val |= val;
>> + omap_temp_sensor_writel(temp_sensor, reg_val,
>> + temp_sensor->registers->bgap_counter);
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> +out:
>> + return count;
>> +}
>> +
>> +static int omap_temp_sensor_read_temp(struct device *dev,
>> + struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> + int temp, ret = 0;
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp &= temp_sensor->registers->bgap_dtemp_mask;
>> +
>> + /* look up for temperature in the table and return the temperature
>> */
>> + if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
>> + dev_err(dev, "invalid adc code reported %d", temp);
>> + ret = -EDOM;
>> + goto out;
>> + }
>> +
>> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
>> +
>> +out:
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> + if (!ret)
>> + return sprintf(buf, "%d\n", temp);
>> +
>> + return ret;
>> +}
>> +
>> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
>> omap_temp_sensor_read_temp,
>> + NULL, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
>> + set_temp_max, 0);
>> +static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
>> show_temp_max_hyst,
>> + set_temp_max_hyst, 0);
>> +static SENSOR_DEVICE_ATTR(update_rate, S_IWUSR | S_IRUGO,
>> show_update_rate,
>> + set_update_rate, 0);
>> +
>> +static struct attribute *omap_temp_sensor_attributes[] = {
>> + &sensor_dev_attr_temp1_input.dev_attr.attr,
>> + &sensor_dev_attr_temp1_max.dev_attr.attr,
>> + &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
>> + &sensor_dev_attr_update_rate.dev_attr.attr,
>> + NULL
>> +};
>> +
>> +static const struct attribute_group omap_temp_sensor_group = {
>> + .attrs = omap_temp_sensor_attributes,
>> +};
>> +
>> +static int omap_temp_sensor_clk_enable(struct omap_temp_sensor
>> *temp_sensor)
>> +{
>> + u32 ret = 0;
>> +
>> + if (temp_sensor->clk_on) {
>> + dev_err(temp_sensor->hwmon_dev, "clock already on\n");
>> + goto out;
>> + }
>> +
>> + ret = pm_runtime_get_sync(temp_sensor->hwmon_dev);
>> + if (ret < 0) {
>> + dev_err(temp_sensor->hwmon_dev, "get sync failed\n");
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp_sensor->clk_on = 1;
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> +out:
>> + return ret;
>> +}
>> +
>> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor
>> *temp_sensor)
>> +{
>> + u32 ret = 0;
>> +
>> + if (!temp_sensor->clk_on) {
>> + dev_err(temp_sensor->hwmon_dev, "clock already off\n");
>> + goto out;
>> + }
>> +
>> + /* Gate the clock */
>> + ret = pm_runtime_put_sync(temp_sensor->hwmon_dev);
>> + if (ret < 0) {
>> + dev_err(temp_sensor->hwmon_dev, "put sync failed\n");
>> + goto out;
>> + }
>> +
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> + temp_sensor->clk_on = 0;
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> +out:
>> + return ret;
>> +}
>> +
>> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
>> +{
>> + struct omap_temp_sensor *temp_sensor;
>> + int t_hot, t_cold, temp;
>> +
>> + temp_sensor = data;
>> + mutex_lock(&temp_sensor->sensor_mutex);
>> +
>> + /* Read the status of t_hot */
>> + t_hot = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_status)
>> + & temp_sensor->registers->status_hot_mask;
>> +
>> + /* Read the status of t_cold */
>> + t_cold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_status)
>> + & temp_sensor->registers->status_cold_mask;
>> +
>> + temp = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + /*
>> + * One TALERT interrupt: Two sources
>> + * If the interrupt is due to t_hot then mask t_hot and
>> + * and unmask t_cold else mask t_cold and unmask t_hot
>> + */
>> + if (t_hot) {
>> + temp &= ~temp_sensor->registers->mask_hot_mask;
>> + temp |= temp_sensor->registers->mask_cold_mask;
>> + } else if (t_cold) {
>> + temp &= ~temp_sensor->registers->mask_cold_mask;
>> + temp |= temp_sensor->registers->mask_hot_mask;
>> + }
>> +
>> + omap_temp_sensor_writel(temp_sensor, temp,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> +
>> + /* kobject_uvent to user space telling thermal threshold crossed
>> */
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_CHANGE);
>> +
>> + mutex_unlock(&temp_sensor->sensor_mutex);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int __devinit omap_temp_sensor_probe(struct platform_device *pdev)
>> +{
>> + struct omap_temp_sensor_pdata *pdata = pdev->dev.platform_data;
>> + struct omap_temp_sensor *temp_sensor;
>> + struct resource *mem;
>> + int ret = 0;
>> + int val, clk_rate;
>> + u32 max_freq, min_freq;
>> +
>> + if (!pdata) {
>> + dev_err(&pdev->dev, "platform data missing\n");
>> + return -EINVAL;
>> + }
>> +
>> + temp_sensor = kzalloc(sizeof(*temp_sensor), GFP_KERNEL);
>> + if (!temp_sensor)
>> + return -ENOMEM;
>> +
>> + mutex_init(&temp_sensor->sensor_mutex);
>> +
>> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!mem) {
>> + dev_err(&pdev->dev, "no mem resource\n");
>> + ret = -ENOMEM;
>> + goto plat_res_err;
>> + }
>> +
>> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
>> + if (temp_sensor->irq < 0) {
>> + dev_err(&pdev->dev, "get_irq_byname failed\n");
>> + ret = temp_sensor->irq;
>> + goto plat_res_err;
>> + }
>> +
>> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>> + temp_sensor->clock = NULL;
>> + temp_sensor->registers = pdata->registers;
>> + temp_sensor->hwmon_dev = &pdev->dev;
>> +
>> + if (pdata->max_freq && pdata->min_freq) {
>> + max_freq = pdata->max_freq;
>> + min_freq = pdata->min_freq;
>> + } else {
>> + max_freq = MAX_FREQ;
>> + min_freq = MIN_FREQ;
>> + }
>> +
>> + pm_runtime_enable(&pdev->dev);
>> + pm_runtime_irq_safe(&pdev->dev);
>> +
>> + /*
>> + * check if the efuse has a non-zero value if not
>> + * it is an untrimmed sample and the temperatures
>> + * may not be accurate
>> + */
>> +
>> + if (omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_efuse)) {
>> + temp_sensor->is_efuse_valid = 1;
>> + dev_dbg(temp_sensor->hwmon_dev,
>> + "Invalid EFUSE, Non-trimmed BGAP, Temp not
>> accurate\n");
>> + }
>> +
>> + dev_set_drvdata(&pdev->dev, temp_sensor);
>> + temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");
>> + if (IS_ERR(temp_sensor->clock)) {
>> + ret = PTR_ERR(temp_sensor->clock);
>> + dev_err(temp_sensor->hwmon_dev,
>> + "unable to get fclk: %d\n", ret);
>> + goto plat_res_err;
>> + }
>> +
>> + ret = omap_temp_sensor_clk_enable(temp_sensor);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Cannot enable temp sensor\n");
>> + goto clken_err;
>> + }
>> +
>> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
>> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
>> + dev_err(&pdev->dev, "Error round rate\n");
>> + ret = -EDOM;
>> + goto clken_err;
>> + }
>> +
>> + ret = clk_set_rate(temp_sensor->clock, clk_rate);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Cannot set clock rate\n");
>> + goto clken_err;
>> + }
>> +
>> + temp_sensor->clk_rate = clk_rate;
>> + omap_enable_continuous_mode(temp_sensor, 1);
>> + omap_configure_temp_sensor_thresholds(temp_sensor);
>> + /* 1 ms */
>> + omap_configure_temp_sensor_counter(temp_sensor, 1);
>> +
>> + /* Wait till the first conversion is done wait for at least 1ms */
>> + usleep_range(1000, 2000);
>> +
>> + /* Read the temperature once due to hw issue*/
>> + omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> +
>> + /* Set 2 seconds time as default counter */
>> + omap_configure_temp_sensor_counter(temp_sensor,
>> + temp_sensor->clk_rate *
>> 2);
>> +
>> + temp_sensor->hwmon_dev = hwmon_device_register(&pdev->dev);
>> + if (IS_ERR(temp_sensor->hwmon_dev)) {
>> + dev_err(&pdev->dev, "hwmon_device_register failed.\n");
>> + ret = PTR_ERR(temp_sensor->hwmon_dev);
>> + goto hwmon_reg_err;
>> + }
>> +
>> + ret = sysfs_create_group(&pdev->dev.kobj,
>> + &omap_temp_sensor_group);
>> + if (ret) {
>> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> + goto sysfs_create_err;
>> + }
>> +
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_ADD);
>> +
>> + ret = request_threaded_irq(temp_sensor->irq, NULL,
>> + omap_talert_irq_handler, IRQF_TRIGGER_RISING |
>> IRQF_ONESHOT,
>> + "temp_sensor", temp_sensor);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Request threaded irq failed.\n");
>> + goto req_irq_err;
>> + }
>> +
>> + /* unmask the T_COLD and unmask T_HOT at init */
>> + val = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + val |= temp_sensor->registers->mask_cold_mask
>> + | temp_sensor->registers->mask_hot_mask;
>> +
>> + omap_temp_sensor_writel(temp_sensor, val,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> +
>> + return 0;
>> +
>> +req_irq_err:
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
>> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
>> + &omap_temp_sensor_group);
>> +sysfs_create_err:
>> + hwmon_device_unregister(&pdev->dev);
>> +hwmon_reg_err:
>> + omap_temp_sensor_clk_disable(temp_sensor);
>> +clken_err:
>> + clk_put(temp_sensor->clock);
>> +plat_res_err:
>> + dev_set_drvdata(&pdev->dev, NULL);
>> + mutex_destroy(&temp_sensor->sensor_mutex);
>> + kfree(temp_sensor);
>> + return ret;
>> +}
>> +
>> +static int __devexit omap_temp_sensor_remove(struct platform_device
>> *pdev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
>> +
>> + hwmon_device_unregister(&pdev->dev);
>> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
>> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
>> + &omap_temp_sensor_group);
>> + omap_temp_sensor_clk_disable(temp_sensor);
>> + free_irq(temp_sensor->irq, temp_sensor);
>> + clk_put(temp_sensor->clock);
>> + dev_set_drvdata(&pdev->dev, NULL);
>> + mutex_destroy(&temp_sensor->sensor_mutex);
>> + kfree(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static void omap_temp_sensor_save_ctxt(struct omap_temp_sensor
>> *temp_sensor)
>> +{
>> + temp_sensor->temp_sensor_ctrl =
>> omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + temp_sensor->bg_ctrl = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + temp_sensor->bg_counter = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_counter);
>> + temp_sensor->bg_threshold = omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->bgap_threshold);
>> + temp_sensor->temp_sensor_tshut_threshold =
>> + omap_temp_sensor_readl(temp_sensor,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static void omap_temp_sensor_restore_ctxt(struct omap_temp_sensor
>> *temp_sensor)
>> +{
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->temp_sensor_ctrl,
>> + temp_sensor->registers->temp_sensor_ctrl);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_ctrl,
>> + temp_sensor->registers->bgap_mask_ctrl);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_counter,
>> + temp_sensor->registers->bgap_counter);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->bg_threshold,
>> + temp_sensor->registers->bgap_threshold);
>> + omap_temp_sensor_writel(temp_sensor,
>> + temp_sensor->temp_sensor_tshut_threshold,
>> + temp_sensor->registers->thsut_threshold);
>> +}
>> +
>> +static int omap_temp_sensor_suspend(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_save_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_resume(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_restore_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_runtime_suspend(struct device *dev)
>> +{
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + omap_temp_sensor_save_ctxt(temp_sensor);
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_runtime_resume(struct device *dev)
>> +{
>> + static int context_loss_count;
>> + int temp;
>> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
>> +
>> + temp =
>> omap_device_get_context_loss_count(to_platform_device(dev));
>> +
>> + if (temp != context_loss_count && context_loss_count != 0)
>> + omap_temp_sensor_restore_ctxt(temp_sensor);
>> +
>> + context_loss_count = temp;
>> +
>> + return 0;
>> +}
>> +
>> +static int omap_temp_sensor_idle(struct device *dev)
>> +{
>> + return 0;
>> +}
>> +
>> +static const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
>> + SET_SYSTEM_SLEEP_PM_OPS(omap_temp_sensor_suspend,
>> + omap_temp_sensor_resume)
>> + SET_RUNTIME_PM_OPS(omap_temp_sensor_runtime_suspend,
>> + omap_temp_sensor_runtime_resume,
>> omap_temp_sensor_idle)
>> +};
>> +
>> +#define DEV_PM_OPS (&omap_temp_sensor_dev_pm_ops)
>> +#else
>> +#define DEV_PM_OPS NULL
>> +#endif
>> +
>> +static struct platform_driver omap_temp_sensor_driver = {
>> + .probe = omap_temp_sensor_probe,
>> + .remove = omap_temp_sensor_remove,
>> + .driver = {
>> + .name = "omap_temp_sensor",
>> + .pm = DEV_PM_OPS,
>> + },
>> +};
>> +
>> +int __init omap_temp_sensor_init(void)
>> +{
>> + return platform_driver_register(&omap_temp_sensor_driver);
>> +}
>> +module_init(omap_temp_sensor_init);
>> +
>> +static void __exit omap_temp_sensor_exit(void)
>> +{
>> + platform_driver_unregister(&omap_temp_sensor_driver);
>> +}
>> +module_exit(omap_temp_sensor_exit);
>> +
>> +MODULE_DESCRIPTION("OMAP446X temperature sensor Driver");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:" DRIVER_NAME);
>> +MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
>> --
>> 1.7.0.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
> --
> Thanks and Regards,
> Janakiram Sistla.
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 18:18 ` J, KEERTHY
@ 2011-08-24 19:52 ` Janakiram Sistla
2011-08-25 0:39 ` J, KEERTHY
0 siblings, 1 reply; 19+ messages in thread
From: Janakiram Sistla @ 2011-08-24 19:52 UTC (permalink / raw)
To: J, KEERTHY; +Cc: linux-omap, lm-sensors
[-- Attachment #1.1: Type: text/plain, Size: 657 bytes --]
On Wed, Aug 24, 2011 at 1:18 PM, J, KEERTHY <j-keerthy@ti.com> wrote:
> On Wed, Aug 24, 2011 at 10:06 PM, Janakiram Sistla
> <janakiram.sistla@gmail.com> wrote:
> > Hi Keerthy,
> >
> > Can you please point me the TRM of 4430 or 4460 where it reads the on die
> > temperature sensor used is TMP103. I am referring to public TRM on TI
> site.
>
> Sorry my bad! I shall remove that.
>
> >
> > Regards,
> > Sistla.
> >
> > On Wed, Aug 24, 2011 at 9:37 AM, Keerthy <j-keerthy@ti.com> wrote:
>
So if my understanding is correct this patch set refers to Band gap Voltage
and Temperature sensor module.
If true can it be mentioned in the patch.
Regards,
Sistla.
[-- Attachment #1.2: Type: text/html, Size: 1144 bytes --]
[-- Attachment #2: Type: text/plain, Size: 153 bytes --]
_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 19:52 ` Janakiram Sistla
@ 2011-08-25 0:39 ` J, KEERTHY
0 siblings, 0 replies; 19+ messages in thread
From: J, KEERTHY @ 2011-08-25 0:39 UTC (permalink / raw)
To: Janakiram Sistla; +Cc: linux-omap, Jean Delvare, Guenter Roeck, lm-sensors
On Thu, Aug 25, 2011 at 1:22 AM, Janakiram Sistla
<janakiram.sistla@gmail.com> wrote:
>
>
> On Wed, Aug 24, 2011 at 1:18 PM, J, KEERTHY <j-keerthy@ti.com> wrote:
>>
>> On Wed, Aug 24, 2011 at 10:06 PM, Janakiram Sistla
>> <janakiram.sistla@gmail.com> wrote:
>> > Hi Keerthy,
>> >
>> > Can you please point me the TRM of 4430 or 4460 where it reads the on
>> > die
>> > temperature sensor used is TMP103. I am referring to public TRM on TI
>> > site.
>>
>> Sorry my bad! I shall remove that.
>>
>> >
>> > Regards,
>> > Sistla.
>> >
>> > On Wed, Aug 24, 2011 at 9:37 AM, Keerthy <j-keerthy@ti.com> wrote:
>
> So if my understanding is correct this patch set refers to Band gap Voltage
> and Temperature sensor module.
> If true can it be mentioned in the patch.
Yes. I will mention that.
>
> Regards,
> Sistla.
>
--
Regards and Thanks,
Keerthy
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-24 14:37 ` [PATCH 6/6 V3] hwmon: OMAP4: On die temperature " Keerthy
2011-08-24 16:36 ` Janakiram Sistla
@ 2011-08-25 7:24 ` Todd Poynor
2011-08-25 15:54 ` Guenter Roeck
1 sibling, 1 reply; 19+ messages in thread
From: Todd Poynor @ 2011-08-25 7:24 UTC (permalink / raw)
To: Keerthy; +Cc: linux-omap, Jean Delvare, Guenter Roeck, lm-sensors
On Wed, Aug 24, 2011 at 08:07:12PM +0530, Keerthy wrote:
...
> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
Check NULL return.
temp_sensor->phy_base is never iounmapped in error paths or _remove
function.
...
> +static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
> +{
> + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
> +
> + hwmon_device_unregister(&pdev->dev);
> + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> + omap_temp_sensor_clk_disable(temp_sensor);
> + free_irq(temp_sensor->irq, temp_sensor);
free_irq before omap_temp_sensor_clk_disable, to avoid ISR attempting
to access hardware while unclocked.
> + clk_put(temp_sensor->clock);
> + dev_set_drvdata(&pdev->dev, NULL);
> + mutex_destroy(&temp_sensor->sensor_mutex);
> + kfree(temp_sensor);
> +
> + return 0;
> +}
Todd
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver
2011-08-25 7:24 ` Todd Poynor
@ 2011-08-25 15:54 ` Guenter Roeck
0 siblings, 0 replies; 19+ messages in thread
From: Guenter Roeck @ 2011-08-25 15:54 UTC (permalink / raw)
To: Todd Poynor
Cc: Keerthy, linux-omap@vger.kernel.org, Jean Delvare,
lm-sensors@lm-sensors.org
On Thu, 2011-08-25 at 03:24 -0400, Todd Poynor wrote:
> On Wed, Aug 24, 2011 at 08:07:12PM +0530, Keerthy wrote:
> ...
> > + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
>
> Check NULL return.
>
> temp_sensor->phy_base is never iounmapped in error paths or _remove
> function.
>
> ...
> > +static int __devexit omap_temp_sensor_remove(struct platform_device *pdev)
> > +{
> > + struct omap_temp_sensor *temp_sensor = platform_get_drvdata(pdev);
> > +
> > + hwmon_device_unregister(&pdev->dev);
Should be
hwmon_device_unregister(temp_sensor->hwmon_dev);
since that is what was registered, but then the following accesses using
temp_sensor->hwmon_dev won't work anymore and should probably use
&pdev->dev.kobj as parameter instead. Overall the use of
temp_sensor->hwmon_dev vs. &pdev->dev looks questionable to me.
> > + kobject_uevent(&temp_sensor->hwmon_dev->kobj, KOBJ_REMOVE);
> > + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> > + &omap_temp_sensor_group);
> > + omap_temp_sensor_clk_disable(temp_sensor);
> > + free_irq(temp_sensor->irq, temp_sensor);
>
> free_irq before omap_temp_sensor_clk_disable, to avoid ISR attempting
> to access hardware while unclocked.
>
Also, t_cold and t_hot interrupts should be disabled before calling
free_irq (and actually before anything is unregistered).
> > + clk_put(temp_sensor->clock);
> > + dev_set_drvdata(&pdev->dev, NULL);
> > + mutex_destroy(&temp_sensor->sensor_mutex);
> > + kfree(temp_sensor);
> > +
> > + return 0;
> > +}
>
> Todd
^ permalink raw reply [flat|nested] 19+ messages in thread
end of thread, other threads:[~2011-08-27 16:37 UTC | newest]
Thread overview: 19+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-08-24 17:16 [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver Guenter Roeck
2011-08-25 10:30 ` J, KEERTHY
2011-08-25 14:06 ` Guenter Roeck
2011-08-25 15:56 ` [lm-sensors] " Guenter Roeck
2011-08-25 16:06 ` J, KEERTHY
2011-08-26 11:17 ` J, KEERTHY
2011-08-26 16:16 ` Guenter Roeck
2011-08-27 16:37 ` J, KEERTHY
2011-08-25 16:04 ` J, KEERTHY
2011-08-25 16:19 ` Guenter Roeck
2011-08-25 16:39 ` J, KEERTHY
2011-08-25 16:49 ` Guenter Roeck
-- strict thread matches above, loose matches on Subject: below --
2011-08-24 14:37 [PATCH 0/6 V3] OMAP4: Temperature " Keerthy
2011-08-24 14:37 ` [PATCH 6/6 V3] hwmon: OMAP4: On die temperature " Keerthy
2011-08-24 16:36 ` Janakiram Sistla
2011-08-24 18:18 ` J, KEERTHY
2011-08-24 19:52 ` Janakiram Sistla
2011-08-25 0:39 ` J, KEERTHY
2011-08-25 7:24 ` Todd Poynor
2011-08-25 15:54 ` Guenter Roeck
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox