Re: [RFC PATCH 6/6] hwmon: OMAP4: On die temperature sensor driver

[Felipe Balbi <balbi@ti.com>]

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Hi,

(why aren't below in Cc ?

HARDWARE MONITORING
M:	Jean Delvare <khali@linux-fr.org>
M:	Guenter Roeck <guenter.roeck@ericsson.com>
L:	lm-sensors@lm-sensors.org
W:	http://www.lm-sensors.org/
T:	quilt kernel.org/pub/linux/kernel/people/jdelvare/linux-2.6/jdelvare-hwmon/
T:	git git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git
S:	Maintained
F:	Documentation/hwmon/
F:	drivers/hwmon/
F:	include/linux/hwmon*.h)

On Wed, Aug 10, 2011 at 05:55:22PM +0530, 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>
> ---
>  drivers/hwmon/Kconfig            |   11 +
>  drivers/hwmon/Makefile           |    1 +
>  drivers/hwmon/omap_temp_sensor.c |  950 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 962 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/hwmon/omap_temp_sensor.c
> 
> 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..15e2559
> --- /dev/null
> +++ b/drivers/hwmon/omap_temp_sensor.c
> @@ -0,0 +1,950 @@
> +/*
> + * 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>

why ??

> +#include <linux/io.h>
> +#include <linux/debugfs.h>

why ??

> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/init.h>
> +#include <plat/omap_device.h>

why ??

> +#include <linux/module.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 <plat/common.h>

why ?

> +#include <plat/temperature_sensor.h>

why ?

> +#include <mach/ctrl_module_core_44xx.h>

why ?

> +#include <mach/gpio.h>

linux/gpio.h for crying out loud... how many times Russell has to say
the exact same thing ??????

> +#define TSHUT_THRESHOLD_HOT	122000	/* 122 deg C */
> +#define TSHUT_THRESHOLD_COLD	100000	/* 100 deg C */
> +#define BGAP_THRESHOLD_T_HOT	73000	/* 73 deg C */
> +#define BGAP_THRESHOLD_T_COLD	71000	/* 71 deg C */
> +#define OMAP_ADC_START_VALUE	530
> +#define OMAP_ADC_END_VALUE	923
> +
> +/*
> + * 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 i;
> +
> +	for (i = 0; i <= OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE; i++)
> +		if (temp < adc_to_temp[i])
> +			return OMAP_ADC_START_VALUE + i - 1;
> +
> +	return -EINVAL;
> +}
> +
> +static void omap_configure_temp_sensor_thresholds(struct omap_temp_sensor
> +						  *temp_sensor)
> +{
> +	u32 temp, t_hot, t_cold, tshut_hot, tshut_cold;
> +
> +	t_hot = temp_to_adc_conversion(BGAP_THRESHOLD_T_HOT);
> +	t_cold = temp_to_adc_conversion(BGAP_THRESHOLD_T_COLD);
> +
> +	/* 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);
> +
> +	tshut_hot = temp_to_adc_conversion(TSHUT_THRESHOLD_HOT);
> +	tshut_cold = temp_to_adc_conversion(TSHUT_THRESHOLD_COLD);
> +
> +	/* 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;
> +
> +	mutex_lock(&temp_sensor->sensor_mutex);
> +
> +	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");
> +		goto out;
> +	}
> +	temp = adc_to_temp_conversion(temp);
> +
> +out:
> +	mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +	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;
> +
> +	mutex_lock(&temp_sensor->sensor_mutex);
> +
> +	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)) {
> +		dev_err(dev, "invalid range\n");
> +		count = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* 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) {
> +		dev_err(dev, "Error! T_HOT value lesser than T_COLD\n");
> +		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);
> +
> +	if (temp < OMAP_ADC_START_VALUE || temp > OMAP_ADC_END_VALUE) {
> +		dev_err(dev, "invalid value\n");
> +		goto out;
> +	}
> +
> +	temp = adc_to_temp_conversion(temp);
> +out:
> +	mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +	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;
> +
> +	mutex_lock(&temp_sensor->sensor_mutex);
> +
> +	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) {
> +		dev_err(dev, "invalid range");
> +		count = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* 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) {
> +		dev_err(dev, "Error! T_COLD value greater than T_HOT\n");
> +		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;
> +
> +	mutex_lock(&temp_sensor->sensor_mutex);
> +
> +	if (!temp_sensor->clk_rate) {
> +		dev_err(dev, "clk_rate is NULL\n");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	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);

	temp &= ??

> +	temp = temp * 1000 / (temp_sensor->clk_rate);

	temp *= ??

> +
> +out:
> +	mutex_unlock(&temp_sensor->sensor_mutex);
> +	if (!ret)
> +		return sprintf(buf, "%d\n", temp);
> +	else
> +		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;
> +
> +	mutex_lock(&temp_sensor->sensor_mutex);
> +
> +	if (strict_strtol(buf, 10, &val)) {
> +		count = -EINVAL;
> +		goto out;
> +	}
> +
> +	val *= temp_sensor->clk_rate / 1000;
> +	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);
> +
> +out:
> +	mutex_unlock(&temp_sensor->sensor_mutex);
> +	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;
> +
> +	if (!temp_sensor->is_efuse_valid)
> +		dev_err(dev, "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n");
> +
> +	/* 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 = -EINVAL;
> +		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);
> +	else
> +		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, temp;
> +
> +	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");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	temp = omap_temp_sensor_readl(temp_sensor,
> +			temp_sensor->registers->temp_sensor_ctrl);
> +	temp &= ~(temp_sensor->registers->bgap_tempsoff_mask);
> +	/* BGAP_TEMPSOFF should be reset to 0 */
> +	omap_temp_sensor_writel(temp_sensor, temp,
> +				temp_sensor->registers->temp_sensor_ctrl);
> +	temp_sensor->clk_on = 1;

why isn't pm_runtime_get_sync() enough ??

> +out:
> +	return ret;
> +}
> +
> +static int omap_temp_sensor_clk_disable(struct omap_temp_sensor *temp_sensor)
> +{
> +	u32 temp, ret = 0;
> +	unsigned long timeout;
> +
> +	if (!temp_sensor->clk_on) {
> +		dev_err(temp_sensor->hwmon_dev, "clock already off\n");
> +		goto out;
> +	}
> +	temp = omap_temp_sensor_readl(temp_sensor,
> +			temp_sensor->registers->temp_sensor_ctrl);
> +	temp |= temp_sensor->registers->bgap_tempsoff_mask;
> +
> +	/* BGAP_TEMPSOFF should be set to 1 before gating clock */
> +	omap_temp_sensor_writel(temp_sensor, temp,
> +			temp_sensor->registers->temp_sensor_ctrl);
> +	temp = omap_temp_sensor_readl(temp_sensor,
> +			temp_sensor->registers->bgap_status);
> +	timeout = jiffies + msecs_to_jiffies(5);
> +
> +	/* wait till the clean stop bit is set or till the timeout exppires */
> +	while (!(temp | temp_sensor->registers->status_clean_stop_mask) &&
> +		!(time_after(jiffies, timeout))) {
> +		temp = omap_temp_sensor_readl(temp_sensor,
> +			temp_sensor->registers->bgap_status);
> +		usleep_range(500, 2000);
> +	}
> +
> +	if (time_after(jiffies, timeout))
> +		dev_err(temp_sensor->hwmon_dev, "Clean stop bit not set\n");
> +	/* 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");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +	temp_sensor->clk_on = 0;
> +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;
> +
> +	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 = -EINVAL;
> +		goto plat_res_err;
> +	}
> +
> +	temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> +	if (temp_sensor->irq == -ENXIO) {
> +		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;
> +
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_irq_safe(&pdev->dev);

won't pm_runtime_irq_safe() keep the parent always running, thus
preventing MPU from reaching lower power states ??

> +	/*
> +	 * 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;
> +
> +	platform_set_drvdata(pdev, temp_sensor);
> +	dev_set_drvdata(&pdev->dev, temp_sensor);

why are you doing the same thing twice ???

> +	temp_sensor->clock = clk_get(temp_sensor->hwmon_dev, "fck");

why ?

> +	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);
> +		ret = -EINVAL;
> +		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, 2000000);

why ?

> +	if (clk_rate < 1000000 || clk_rate == 0xffffffff) {
> +		dev_err(&pdev->dev, "Error round rate\n");
> +		goto clken_err;
> +	}
> +
> +	ret = clk_set_rate(temp_sensor->clock, clk_rate);

why ??

> +	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:
> +	if (temp_sensor->clock)
> +		clk_put(temp_sensor->clock);
> +plat_res_err:
> +	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);
> +	clk_put(temp_sensor->clock);
> +	platform_set_drvdata(pdev, NULL);
> +	free_irq(temp_sensor->irq, temp_sensor);
> +	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 const struct dev_pm_ops omap_temp_sensor_dev_pm_ops = {
> +	.suspend = omap_temp_sensor_suspend,
> +	.resume = omap_temp_sensor_resume,
> +	.runtime_suspend = omap_temp_sensor_runtime_suspend,
> +	.runtime_resume = omap_temp_sensor_runtime_resume,
> +};
> +
> +#endif
> +
> +static struct platform_driver omap_temp_sensor_driver = {
> +	.probe = omap_temp_sensor_probe,
> +	.remove = omap_temp_sensor_remove,
> +	.driver = {
> +			.name = "omap_temp_sensor",
> +#ifdef CONFIG_PM
> +			.pm = &omap_temp_sensor_dev_pm_ops,
> +#endif
> +		   },
> +};
> +
> +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
> 
> --
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-- 
balbi

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