[lm-sensors] [PATCH 6/6 V3] hwmon: OMAP4: On die temperature sensor driver

J, KEERTHY j-keerthy at ti.com
Thu Aug 25 12:30:07 CEST 2011


On Wed, Aug 24, 2011 at 10:46 PM, Guenter Roeck
<guenter.roeck at 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 at ti.com>
>> Cc: Jean Delvare <khali at linux-fr.org>
>> Cc: Guenter Roeck <guenter.roeck at ericsson.com>
>> Cc: lm-sensors at 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 at 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 at ti.com>
>> + * Author: Moiz Sonasath <m-sonasath at 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 at ti.com>");
>> --
>> 1.7.0.4
>>
>



-- 
Regards and Thanks,
Keerthy




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