Re: [PATCH] Driver for omap34xx temperature sensor. second version.

[Tony Lindgren <tony@atomide.com>]

* Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com> [080523 03:50]:
> Hi,
> 
> This patch adds a hwmon driver for the OMAP34xx internal temperature
> sensor. I get unusually high values (80 degrees and more) from this
> sensor though. 
> 
> Comments welcome.

Pushing today.

Tony

>  
> Signed-off-by: Peter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
> ---
>  drivers/hwmon/Kconfig               |    4 +
>  drivers/hwmon/Makefile              |    1 +
>  drivers/hwmon/omap34xx_temp.c       |  268 +++++++++++++++++++++++++++++++++++
>  include/asm-arm/arch-omap/control.h |    1 +
>  4 files changed, 274 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/hwmon/omap34xx_temp.c
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 90c6812..3e42df6 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -797,6 +797,10 @@ config SENSORS_TSC210X
>  	  This driver can also be built as a module.  In this case
>  	  the module will be called tsc210x_sensors.
>  
> +config SENSORS_OMAP34XX
> +	tristate "TI OMAP34xx internal temperature sensor"
> +	depends on ARCH_OMAP3 && HIGH_RES_TIMERS
> +
>  config HWMON_DEBUG_CHIP
>  	bool "Hardware Monitoring Chip debugging messages"
>  	default n
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 8e401f2..565303f 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -72,6 +72,7 @@ obj-$(CONFIG_SENSORS_W83627EHF)	+= w83627ehf.o
>  obj-$(CONFIG_SENSORS_W83L785TS)	+= w83l785ts.o
>  obj-$(CONFIG_SENSORS_TSC210X)	+= tsc210x_sensors.o
>  obj-$(CONFIG_SENSORS_W83L786NG)	+= w83l786ng.o
> +obj-$(CONFIG_SENSORS_OMAP34XX)  += omap34xx_temp.o
>  
>  ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
>  EXTRA_CFLAGS += -DDEBUG
> diff --git a/drivers/hwmon/omap34xx_temp.c b/drivers/hwmon/omap34xx_temp.c
> new file mode 100644
> index 0000000..bcb3c9a
> --- /dev/null
> +++ b/drivers/hwmon/omap34xx_temp.c
> @@ -0,0 +1,268 @@
> +/*
> + * omap34xx_temp.c - Linux kernel module for OMAP34xx hardware monitoring
> + *
> + * Copyright (C) 2008 Nokia Corporation
> + *
> + * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
> + *
> + * Inspired by k8temp.c
> + *
> + * This file is subject to the terms and conditions of the GNU General
> + * Public License. See the file "COPYING" in the main directory of this
> + * archive for more details.
> + *
> + * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/hrtimer.h>
> +#include <linux/module.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <asm/arch/omap34xx.h>
> +#include <asm/arch/control.h>
> +
> +#define TEMP_SENSOR_SOC BIT(8)
> +#define TEMP_SENSOR_EOCZ BIT(7)
> +
> +/* minimum delay for EOCZ rise after SOC rise is
> + * 11 cycles of the 32.768Khz clock */
> +#define EOCZ_MIN_RISING_DELAY (11 * 30518)
> +
> +/* maximum delay for EOCZ rise after SOC rise is
> + * 14 cycles of the 32.768Khz clock */
> +#define EOCZ_MAX_RISING_DELAY (14 * 30518)
> +
> +/* minimum delay for EOCZ falling is
> + * 36 cycles of the 32.768Khz clock */
> +#define EOCZ_MIN_FALLING_DELAY (36 * 30518)
> +
> +/* maximum delay for EOCZ falling is
> + * 40 cycles of the 32.768Khz clock */
> +#define EOCZ_MAX_FALLING_DELAY (40 * 30518)
> +
> +struct omap34xx_data {
> +	struct device *hwmon_dev;
> +	struct clk *clk_32k;
> +	struct mutex update_lock;
> +	const char *name;
> +	char valid;
> +	unsigned long last_updated;
> +	u32 temp;
> +};
> +
> +static struct platform_device omap34xx_temp_device = {
> +	.name 	= "omap34xx_temp",
> +	.id	= -1,
> +};
> +
> +static int adc_to_temp[] = {
> +	-40, -40, -40, -40, -40, -39, -38, -36, -34, -32, -31, -29, -28, -26,
> +	-25, -24, -22, -21, -19, -18, -17, -15, -14, -12, -11, -9, -8, -7, -5,
> +	-4, -2, -1, 0, 1, 3, 4, 5, 7, 8, 10, 11, 13, 14, 15, 17, 18, 20, 21,
> +	22, 24, 25, 27, 28, 30, 31, 32, 34, 35, 37, 38, 39, 41, 42, 44, 45,
> +	47, 48, 49, 51, 52, 53, 55, 56, 58, 59, 60, 62, 63, 65, 66, 67, 69,
> +	70, 72, 73, 74, 76, 77, 79, 80, 81, 83, 84, 85, 87, 88, 89, 91, 92,
> +	94, 95, 96, 98, 99, 100, 102, 103, 105, 106, 107, 109, 110, 111, 113,
> +	114, 116, 117, 118, 120, 121, 122, 124, 124, 125, 125, 125, 125, 125};
> +
> +static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level)
> +{
> +	struct timespec timeout;
> +	ktime_t expire;
> +	u32 temp_sensor_reg;
> +
> +	level &= 1;
> +	level *= TEMP_SENSOR_EOCZ;
> +
> +	expire = ktime_add_ns(ktime_get(), max_delay);
> +	timeout = ns_to_timespec(min_delay);
> +	hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
> +	do {
> +		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
> +		if ((temp_sensor_reg & TEMP_SENSOR_EOCZ) == level)
> +			break;
> +	} while (ktime_us_delta(expire, ktime_get()) > 0);
> +
> +	return (temp_sensor_reg & TEMP_SENSOR_EOCZ) == level;
> +}
> +
> +static void omap34xx_update(struct omap34xx_data *data)
> +{
> +	u32 temp_sensor_reg;
> +
> +	mutex_lock(&data->update_lock);
> +
> +	if (!data->valid
> +	    || time_after(jiffies, data->last_updated + HZ)) {
> +
> +		clk_enable(data->clk_32k);
> +
> +		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
> +		temp_sensor_reg |= TEMP_SENSOR_SOC;
> +		omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR);
> +
> +		if (!wait_for_eocz(EOCZ_MIN_RISING_DELAY,
> +					EOCZ_MAX_RISING_DELAY, 1))
> +			goto err;
> +
> +		temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR);
> +		temp_sensor_reg &= ~TEMP_SENSOR_SOC;
> +		omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR);
> +
> +		if (!wait_for_eocz(EOCZ_MIN_FALLING_DELAY,
> +					EOCZ_MAX_FALLING_DELAY, 0))
> +			goto err;
> +
> +		data->temp = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR) &
> +						((1<<7) - 1);
> +		data->last_updated = jiffies;
> +		data->valid = 1;
> +
> +err:
> +		clk_disable(data->clk_32k);
> +	}
> +
> +	mutex_unlock(&data->update_lock);
> +}
> +
> +static ssize_t show_name(struct device *dev,
> +			struct device_attribute *devattr, char *buf)
> +{
> +	struct omap34xx_data *data = dev_get_drvdata(dev);
> +
> +	return sprintf(buf, "%s\n", data->name);
> +}
> +
> +static ssize_t show_temp_raw(struct device *dev,
> +			 struct device_attribute *devattr, char *buf)
> +{
> +	struct omap34xx_data *data = dev_get_drvdata(dev);
> +
> +	omap34xx_update(data);
> +
> +	return sprintf(buf, "%d\n", data->temp);
> +}
> +
> +static ssize_t show_temp(struct device *dev,
> +			 struct device_attribute *devattr, char *buf)
> +{
> +	struct omap34xx_data *data = dev_get_drvdata(dev);
> +
> +	omap34xx_update(data);
> +
> +	return sprintf(buf, "%d\n", adc_to_temp[data->temp]);
> +}
> +
> +static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0);
> +static SENSOR_DEVICE_ATTR_2(temp1_input_raw, S_IRUGO, show_temp_raw,
> +				NULL, 0, 0);
> +static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
> +
> +static int __devinit omap34xx_temp_probe(void)
> +{
> +	int err;
> +	struct omap34xx_data *data;
> +
> +	err = platform_device_register(&omap34xx_temp_device);
> +	if (err) {
> +		printk(KERN_ERR
> +			"Unable to register omap34xx temperature device\n");
> +		goto exit;
> +	}
> +
> +	data = kzalloc(sizeof(struct omap34xx_data), GFP_KERNEL);
> +	if (!data) {
> +		err = -ENOMEM;
> +		goto exit_platform;
> +	}
> +
> +	dev_set_drvdata(&omap34xx_temp_device.dev, data);
> +	mutex_init(&data->update_lock);
> +	data->name = "omap34xx_temp";
> +
> +	data->clk_32k = clk_get(&omap34xx_temp_device.dev, "ts_fck");
> +	if (IS_ERR(data->clk_32k)) {
> +		err = PTR_ERR(data->clk_32k);
> +		goto exit_free;
> +	}
> +
> +	err = device_create_file(&omap34xx_temp_device.dev,
> +				 &sensor_dev_attr_temp1_input.dev_attr);
> +	if (err)
> +		goto clock_free;
> +
> +	err = device_create_file(&omap34xx_temp_device.dev,
> +				 &sensor_dev_attr_temp1_input_raw.dev_attr);
> +	if (err)
> +		goto exit_remove;
> +
> +	err = device_create_file(&omap34xx_temp_device.dev, &dev_attr_name);
> +	if (err)
> +		goto exit_remove_raw;
> +
> +	data->hwmon_dev = hwmon_device_register(&omap34xx_temp_device.dev);
> +
> +	if (IS_ERR(data->hwmon_dev)) {
> +		err = PTR_ERR(data->hwmon_dev);
> +		goto exit_remove_all;
> +	}
> +
> +	return 0;
> +
> +exit_remove_all:
> +	device_remove_file(&omap34xx_temp_device.dev,
> +			   &dev_attr_name);
> +exit_remove_raw:
> +	device_remove_file(&omap34xx_temp_device.dev,
> +			   &sensor_dev_attr_temp1_input_raw.dev_attr);
> +exit_remove:
> +	device_remove_file(&omap34xx_temp_device.dev,
> +			   &sensor_dev_attr_temp1_input.dev_attr);
> +clock_free:
> +	clk_put(data->clk_32k);
> +
> +exit_free:
> +	kfree(data);
> +exit_platform:
> +	platform_device_unregister(&omap34xx_temp_device);
> +exit:
> +	return err;
> +}
> +
> +static int __init omap34xx_temp_init(void)
> +{
> +	return omap34xx_temp_probe();
> +}
> +
> +static void __exit omap34xx_temp_exit(void)
> +{
> +	struct omap34xx_data *data =
> +			dev_get_drvdata(&omap34xx_temp_device.dev);
> +
> +	clk_put(data->clk_32k);
> +	hwmon_device_unregister(data->hwmon_dev);
> +	device_remove_file(&omap34xx_temp_device.dev,
> +			   &sensor_dev_attr_temp1_input.dev_attr);
> +	device_remove_file(&omap34xx_temp_device.dev, &dev_attr_name);
> +	kfree(data);
> +	platform_device_unregister(&omap34xx_temp_device);
> +}
> +
> +MODULE_AUTHOR("Peter De Schrijver");
> +MODULE_DESCRIPTION("Omap34xx temperature sensor");
> +MODULE_LICENSE("GPL");
> +
> +module_init(omap34xx_temp_init)
> +module_exit(omap34xx_temp_exit)
> +
> diff --git a/include/asm-arm/arch-omap/control.h b/include/asm-arm/arch-omap/control.h
> index 9944bb5..510069b 100644
> --- a/include/asm-arm/arch-omap/control.h
> +++ b/include/asm-arm/arch-omap/control.h
> @@ -134,6 +134,7 @@
>  #define OMAP343X_CONTROL_TEST_KEY_13	(OMAP2_CONTROL_GENERAL + 0x00fc)
>  #define OMAP343X_CONTROL_IVA2_BOOTADDR	(OMAP2_CONTROL_GENERAL + 0x0190)
>  #define OMAP343X_CONTROL_IVA2_BOOTMOD	(OMAP2_CONTROL_GENERAL + 0x0194)
> +#define OMAP343X_CONTROL_TEMP_SENSOR	(OMAP2_CONTROL_GENERAL + 0x02b4)
>  
>  /*
>   * REVISIT: This list of registers is not comprehensive - there are more
> -- 
> 1.5.3.4
> 
> 
> -- 
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