[PATCH] Driver for omap34xx temperature sensor.

[PATCH] Driver for omap34xx temperature sensor.

[Peter 'p2' De Schrijver]

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.

Cheers,

Peter.

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 |  266 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 271 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..8cd2f8c
--- /dev/null
+++ b/drivers/hwmon/omap34xx_temp.c
@@ -0,0 +1,266 @@
+/*
+ * omap34xx_temp.c - Linux kernem 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>
+
+#define SCM_CONTROL_TEMP_SENSOR	(OMAP343X_SCM_BASE + 0x524)
+#define CM_FCLKEN3_CORE (OMAP3430_CM_BASE + 0x200 + 0x8)
+#define TEMP_SENSOR_SOC (1<<8)
+#define TEMP_SENSOR_EOCZ (1<<7)
+
+/* minimum delay for EOCZ rise after SOC rise is
+ * 11 cycles of the 32Khz clock */
+#define EOCZ_MIN_RISING_DELAY (11 * 31250)
+
+/* maximum delay for EOCZ rise after SOC rise is
+ * 16 cycles of the 32Khz clock */
+#define EOCZ_MAX_RISING_DELAY (16 * 31250)
+
+/* minimum delay for EOCZ falling is
+ * 36 cycles of the 32Khz clock */
+#define EOCZ_MIN_FALLING_DELAY (36 * 31250)
+
+/* maximum delay for EOCZ falling is
+ * 42 cycles of the 32Khz clock */
+#define EOCZ_MAX_FALLING_DELAY (42 * 31250)
+
+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 void omap34xx_update(struct omap34xx_data *data)
+{
+	u32 temp_sensor_reg;
+	struct timespec timeout;
+
+	mutex_lock(&data->update_lock);
+
+	if (!data->valid
+	    || time_after(jiffies, data->last_updated + HZ)) {
+
+		ktime_t expire;
+
+		clk_enable(data->clk_32k);
+
+		temp_sensor_reg = omap_readl(SCM_CONTROL_TEMP_SENSOR);
+		temp_sensor_reg |= TEMP_SENSOR_SOC;
+		omap_writel(temp_sensor_reg, SCM_CONTROL_TEMP_SENSOR);
+
+		expire = ktime_add_ns(ktime_get(), EOCZ_MAX_RISING_DELAY);
+		timeout = ns_to_timespec(EOCZ_MIN_RISING_DELAY);
+		hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL,
+					CLOCK_MONOTONIC);
+		do {
+			temp_sensor_reg = omap_readl(SCM_CONTROL_TEMP_SENSOR);
+			if (temp_sensor_reg & TEMP_SENSOR_EOCZ)
+				break;
+		} while (ktime_us_delta(expire, ktime_get()) > 0);
+
+		if (!(temp_sensor_reg & TEMP_SENSOR_EOCZ))
+			goto err;
+
+		temp_sensor_reg &= ~TEMP_SENSOR_SOC;
+		omap_writel(temp_sensor_reg, SCM_CONTROL_TEMP_SENSOR);
+
+		expire = ktime_add_ns(ktime_get(), EOCZ_MAX_FALLING_DELAY);
+		timeout = ns_to_timespec(EOCZ_MIN_FALLING_DELAY);
+		hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL,
+					CLOCK_MONOTONIC);
+
+		do {
+			temp_sensor_reg = omap_readl(SCM_CONTROL_TEMP_SENSOR);
+			if (!(temp_sensor_reg & TEMP_SENSOR_EOCZ))
+				break;
+		} while (ktime_us_delta(expire, ktime_get()) > 0);
+
+		if (temp_sensor_reg & TEMP_SENSOR_EOCZ)
+			goto err;
+
+		data->temp = omap_readl(SCM_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;
+	}
+
+	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, "omap_32ksync_ick");
+	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:
+	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);
+}
+
+MODULE_AUTHOR("Peter De Schrijver");
+MODULE_DESCRIPTION("Omap34xx temperature sensor");
+MODULE_LICENSE("GPL");
+
+module_init(omap34xx_temp_init)
+module_exit(omap34xx_temp_exit)
+
-- 
1.5.3.4

-- 
goa is a state of mind

Re: [PATCH] Driver for omap34xx temperature sensor.

[Paul Walmsley]

Hi Peter,

a few quick comments.

On Mon, 19 May 2008, Peter 'p2' De Schrijver wrote:

> +#define SCM_CONTROL_TEMP_SENSOR	(OMAP343X_SCM_BASE + 0x524)

Consider moving this to include/asm-arm/arch-omap/control.h ?

> +#define CM_FCLKEN3_CORE (OMAP3430_CM_BASE + 0x200 + 0x8)

The above define doesn't appear to be used.

> +/* minimum delay for EOCZ rise after SOC rise is
> + * 11 cycles of the 32Khz clock */
> +#define EOCZ_MIN_RISING_DELAY (11 * 31250)

Doesn't the 32k sync timer run at 32KiHz == 32768 cycles/second?  I wonder 
if this might be affecting the temperature values.  

> +		temp_sensor_reg = omap_readl(SCM_CONTROL_TEMP_SENSOR);
> +		temp_sensor_reg |= TEMP_SENSOR_SOC;
> +		omap_writel(temp_sensor_reg, SCM_CONTROL_TEMP_SENSOR);

Consider ctrl_{read,write}_reg() instead.

> +		temp_sensor_reg &= ~TEMP_SENSOR_SOC;
> +		omap_writel(temp_sensor_reg, SCM_CONTROL_TEMP_SENSOR);

Likewise.

> +
> +		expire = ktime_add_ns(ktime_get(), EOCZ_MAX_FALLING_DELAY);
> +		timeout = ns_to_timespec(EOCZ_MIN_FALLING_DELAY);
> +		hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL,
> +					CLOCK_MONOTONIC);
> +
> +		do {
> +			temp_sensor_reg = omap_readl(SCM_CONTROL_TEMP_SENSOR);
> +			if (!(temp_sensor_reg & TEMP_SENSOR_EOCZ))
> +				break;
> +		} while (ktime_us_delta(expire, ktime_get()) > 0);
> +
> +		if (temp_sensor_reg & TEMP_SENSOR_EOCZ)
> +			goto err;

The code in the above block is duplicated twice with only a few parameter 
changes -- perhaps move this into a function? 

> +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;
> +	}

All of the following error paths in this function should call 
platform_device_unregister() also, correct?

> +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);

Should this also include a platform_device_unregister()?

> +}


- Paul

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

[Peter 'p2' De Schrijver]

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.
 
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


-- 
goa is a state of mind

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

[Tony Lindgren]

* 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
> 
> 
> -- 
> goa is a state of mind
> --
> 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

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

[Koen Kooi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


Op 23 mei 2008, om 12:49 heeft Peter 'p2' De Schrijver het volgende  
geschreven:

> 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.

Same high values here as well:

root@beagleboard:/sys/class/hwmon/hwmon0/device# cat temp1_input
96

does anyone from TI have a hint if the chip is really that hot, or  
that we need to scale the value?

regards,

Koen
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (Darwin)

iD8DBQFIPeXiMkyGM64RGpERAu+fAJ46X1J6jgnW5IAEs/o8CwhqtxIfGgCeNWpC
RszRjwBZV1f/C1c+w6jmhDE=
=PhBJ
-----END PGP SIGNATURE-----

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

[Tony Lindgren]

* Koen Kooi <k.kooi@student.utwente.nl> [080528 16:08]:
> 
> Op 23 mei 2008, om 12:49 heeft Peter 'p2' De Schrijver het volgende  
> geschreven:
> 
> > 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.
> 
> Same high values here as well:
> 
> root@beagleboard:/sys/class/hwmon/hwmon0/device# cat temp1_input
> 96
> 
> does anyone from TI have a hint if the chip is really that hot, or  
> that we need to scale the value?

Maybe it's in Fahrenheit?

Tony

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

[Koen Kooi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


Op 29 mei 2008, om 01:12 heeft Tony Lindgren het volgende geschreven:

> * Koen Kooi <k.kooi@student.utwente.nl> [080528 16:08]:
>>
>> Op 23 mei 2008, om 12:49 heeft Peter 'p2' De Schrijver het volgende
>> geschreven:
>>
>>> 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.
>>
>> Same high values here as well:
>>
>> root@beagleboard:/sys/class/hwmon/hwmon0/device# cat temp1_input
>> 96
>>
>> does anyone from TI have a hint if the chip is really that hot, or
>> that we need to scale the value?
>
> Maybe it's in Fahrenheit?

That was my first thought, but looking that the omap3530 TRM  
(spruf98.pdf) on page 836:

ADC code  Temperature °C
                     From    To
0                 -40         -40
32               -0.7        0.8
64                44.9      46.3
96                89.3      90.6

And that maps to the adc_to_temp var at line 69 from http://source.mvista.com/git/gitweb.cgi?p=linux-omap-2.6.git;a=blob;f=drivers/hwmon/omap34xx_temp.c
Even if it didn't map, the raw ADC value is  only ±6 °C off from the  
real temperature around that point. So the adc value the kernel reads  
gets translated correctly to °C, so if we think it's incorrect, the  
kernel might be reading the ADC wrong.

regards,

Koen


>
>
> Tony
>

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (Darwin)

iD8DBQFIPlmiMkyGM64RGpERAgfsAJ9H6kOLLP3T4Nlt03UwmwXMsl4lBQCfcJVz
j8wEOY13ggcCsXY4rU7FOuA=
=//co
-----END PGP SIGNATURE-----
--
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

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

[Peter 'p2' De Schrijver]

Hi,

>>> root@beagleboard:/sys/class/hwmon/hwmon0/device# cat temp1_input
>>> 96
>>>
>>> does anyone from TI have a hint if the chip is really that hot, or
>>> that we need to scale the value?
>>
>> Maybe it's in Fahrenheit?
>
> That was my first thought, but looking that the omap3530 TRM  
> (spruf98.pdf) on page 836:
>
> ADC code  Temperature °C
>                     From    To
> 0                 -40         -40
> 32               -0.7        0.8
> 64                44.9      46.3
> 96                89.3      90.6
>
> And that maps to the adc_to_temp var at line 69 from http://source.mvista.com/git/gitweb.cgi?p=linux-omap-2.6.git;a=blob;f=drivers/hwmon/omap34xx_temp.c
> Even if it didn't map, the raw ADC value is  only ±6 °C off from the  
> real temperature around that point. So the adc value the kernel reads  
> gets translated correctly to °C, so if we think it's incorrect, the  
> kernel might be reading the ADC wrong.
>

The driver basically does what's described in figure 7-16 of the
omap3430 TRM. Ie, rise SOC, wait until EOCZ rises, lower SOC, wait EOCZ
goes low, read result. The timeouts are taken directly from this figure.
So I can't really see what the driver would be doing wrong, unless
obviously the hardware doesn't work the way the TRM describes :)

Cheers,

Peter.
-- 
goa is a state of mind
--
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

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

[Koen Kooi]

[-- Attachment #1: Type: text/plain, Size: 1763 bytes --]


Op 29 mei 2008, om 14:42 heeft Peter 'p2' De Schrijver het volgende  
geschreven:

> Hi,
>
>>>> root@beagleboard:/sys/class/hwmon/hwmon0/device# cat temp1_input
>>>> 96
>>>>
>>>> does anyone from TI have a hint if the chip is really that hot, or
>>>> that we need to scale the value?
>>>
>>> Maybe it's in Fahrenheit?
>>
>> That was my first thought, but looking that the omap3530 TRM
>> (spruf98.pdf) on page 836:
>>
>> ADC code  Temperature °C
>>                    From    To
>> 0                 -40         -40
>> 32               -0.7        0.8
>> 64                44.9      46.3
>> 96                89.3      90.6
>>
>> And that maps to the adc_to_temp var at line 69 from http://source.mvista.com/git/gitweb.cgi?p=linux-omap-2.6.git;a=blob;f=drivers/hwmon/omap34xx_temp.c
>> Even if it didn't map, the raw ADC value is  only ±6 °C off from the
>> real temperature around that point. So the adc value the kernel reads
>> gets translated correctly to °C, so if we think it's incorrect, the
>> kernel might be reading the ADC wrong.
>>
>
> The driver basically does what's described in figure 7-16 of the
> omap3430 TRM. Ie, rise SOC, wait until EOCZ rises, lower SOC, wait  
> EOCZ
> goes low, read result. The timeouts are taken directly from this  
> figure.
> So I can't really see what the driver would be doing wrong, unless
> obviously the hardware doesn't work the way the TRM describes :)

Some interesting observations:

root@beagleboard:~# cat /sys/devices/platform/omap34xx_temp/temp1_input
45
root@omap3evm:~# cat /sys/devices/platform/omap34xx_temp/temp1_input
80

The beagle is using an ES3.0 omap3, the evm an ES2.1 omap3, so I  
suspect something got fixed in between :)

regards,

Koen

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 186 bytes --]