On Wed, Aug 31, 2011 at 01:25:10PM -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-keer...@ti.com>
> Cc: Jean Delvare <kh...@linux-fr.org>
> Cc: Guenter Roeck <guenter.ro...@ericsson.com>
> Cc: lm-sens...@lm-sensors.org
> ---
> Documentation/hwmon/omap_temp_sensor | 26 +
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/omap_temp_sensor.c | 881
> ++++++++++++++++++++++++++++++++++
> 4 files changed, 919 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..357f09a
> --- /dev/null
> +++ b/Documentation/hwmon/omap_temp_sensor
> @@ -0,0 +1,26 @@
> +Kernel driver omap_temp_sensor
> +==============================
> +
> +Supported chips:
> + * Texas Instruments OMAP4460
> + Prefix: 'omap_temp_sensor'
> +
> +Author:
> + J Keerthy <j-keer...@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 milliseconds).
> +
> +The driver provides the common sysfs-interface for temperatures (see
> +Documentation/hwmon/sysfs-interface under Temperatures).
> +
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 5f888f7..9c9cd8b 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -323,6 +323,17 @@ config SENSORS_F71805F
> This driver can also be built as a module. If so, the module
> will be called f71805f.
>
> +config SENSORS_OMAP_BANDGAP_TEMP_SENSOR
> + bool "OMAP on-die temperature sensor hwmon driver"
> + depends on HWMON && ARCH_OMAP && OMAP_TEMP_SENSOR
> + help
> + If you say yes here you get support for hardware
> + monitoring features of the OMAP on die temperature
> + sensor.
> +
> + Continuous conversion programmable delay
> + mode is used for temperature conversion.
> +
> config SENSORS_F71882FG
> tristate "Fintek F71882FG and compatibles"
> help
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 28061cf..d0f89f5 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -91,6 +91,7 @@ obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> +obj-$(CONFIG_SENSORS_OMAP_BANDGAP_TEMP_SENSOR) += omap_temp_sensor.o
> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
> diff --git a/drivers/hwmon/omap_temp_sensor.c
> b/drivers/hwmon/omap_temp_sensor.c
> new file mode 100644
> index 0000000..67fa424
> --- /dev/null
> +++ b/drivers/hwmon/omap_temp_sensor.c
> @@ -0,0 +1,881 @@
> +/*
> + * OMAP4 Temperature sensor driver file
> + *
> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
> + * Author: J Keerthy <j-keer...@ti.com>
> + * Author: Moiz Sonasath <m-sonas...@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
> +#define MIN_TEMP -40000
> +#define MAX_TEMP 123000
> +#define HYST_VAL 5000
> +#define NEG_HYST_VAL -5000
> +/*
> + * omap_temp_sensor structure
> + * @hwmon_dev - hwmon device pointer
> + * @pdev_dev - platform 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
> + * @clk_on - Manages the current clock state
> + */
> +struct omap_temp_sensor {
> + struct device *hwmon_dev;
> + struct device *pdev_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 clk_on;
> +};
> +
> +/*
> + * Temperature values in milli degree celsius
> + * ADC code values from 530 to 923
> + */
> +static int adc_to_temp[394] = {
[OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE + 1]
> + -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)
Why unsigned long ? Result is lways assigned to u32 or int.
> +{
> + return __raw_readl(temp_sensor->phy_base + reg);
> +}
> +
> +static void omap_temp_sensor_writel(struct omap_temp_sensor *temp_sensor,
> + u32 val, u32 reg)
> +{
> + __raw_writel(val, temp_sensor->phy_base + reg);
> +}
> +
> +static int adc_to_temp_conversion(int adc_val)
> +{
> + return adc_to_temp[adc_val - OMAP_ADC_START_VALUE];
> +}
> +
> +static int temp_to_adc_conversion(long temp)
> +{
> + int high, low, mid;
> +
> + if (temp < adc_to_temp[0] ||
> + temp > adc_to_temp[OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE])
> + return -EINVAL;
> +
> + high = OMAP_ADC_END_VALUE - OMAP_ADC_START_VALUE;
> + low = 0;
> + mid = (high + low) / 2;
> +
> + while (low < high) {
> + if (temp < adc_to_temp[mid])
> + high = mid - 1;
> + else
> + low = mid + 1;
> + mid = (low + high) / 2;
> + }
> +
> + return OMAP_ADC_START_VALUE + low;
> +}
> +
> +static void omap_configure_temp_sensor_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)
> +{
Please add a comment to functions which need to be called during initialization
or
protected by the mutex.
> + u32 val;
> +
> + val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mode_ctrl);
> +
> + val |= 1 << __ffs(temp_sensor->registers->mode_ctrl_mask);
> +
> + omap_temp_sensor_writel(temp_sensor, val,
> + temp_sensor->registers->bgap_mode_ctrl);
> +}
> +
> +static void omap_temp_sensor_unmask_interrupts(struct omap_temp_sensor
> + *temp_sensor, u8 hot, u8 cold)
> +{
> + u32 reg_val;
> +
> + reg_val = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_mask_ctrl);
> + if (hot)
> + reg_val |= temp_sensor->registers->mask_hot_mask;
> + else
> + reg_val &= ~temp_sensor->registers->mask_hot_mask;
> +
> + if (cold)
> + reg_val |= temp_sensor->registers->mask_cold_mask;
> + else
> + reg_val &= ~temp_sensor->registers->mask_cold_mask;
> +
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_mask_ctrl);
> +}
> +
> +static void add_hyst(int adc_val, int hyst_val, int *thresh_val)
> +{
> + int temp = adc_to_temp_conversion(adc_val);
> +
> + temp += hyst_val;
> +
> + *thresh_val = temp_to_adc_conversion(temp);
> +}
> +
Since you return a void, you can as well return the new value and drop the
pointer.
> +static void omap_temp_sensor_configure_thresholds_mask(struct
> omap_temp_sensor
> + *temp_sensor, bool set_hot, bool set_cold, int t_hot, int t_cold)
> +{
> + int reg_val, cold, hot, temp;
> +
Why int here ?
> + if (set_hot) {
> + /* obtain the T cold value */
> + cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + cold = (cold & temp_sensor->registers->threshold_tcold_mask)
> + >>
> __ffs(temp_sensor->registers->threshold_tcold_mask);
> +
> + if (t_hot < cold) {
> + /* change the t_cold to t_hot - 5000 millidegrees */
> + add_hyst(t_hot, NEG_HYST_VAL, &cold);
You might just use -HYST_VAL here.
> + /* 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 |= cold <<
> + __ffs(temp_sensor->registers->threshold_tcold_mask);
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> + t_cold = cold;
> + }
> +
t_hot == cold: t_hot will be equal to t_cold
t_hot > t_colt: t_hot > t_cold, any difference
t_hot < t_cold: t_cold == t_hot - NEG_HYST_VAL
Seems to be inconsistent, and it seems that the condition t_hot == t_cold can
still occur
(which you mentioned earlier would be invalid). If you want to define a minimum
hysteresis,
you should enforce it by modifying the if statement.
> + /* 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);
> + }
> +
> + if (set_cold) {
> + /* obtain the T HOT value */
> + hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + hot = (hot & temp_sensor->registers->threshold_thot_mask) >>
> + __ffs(temp_sensor->registers->threshold_thot_mask);
> + if (t_cold > hot) {
> + /* change the t_hot to t_cold + 5000 millidegrees */
> + add_hyst(t_cold, HYST_VAL, &hot);
> + /* 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 |= (hot <<
> + __ffs(temp_sensor->registers->threshold_thot_mask));
> + omap_temp_sensor_writel(temp_sensor, reg_val,
> + temp_sensor->registers->bgap_threshold);
> + t_hot = hot;
> + }
> +
> + /* 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);
> + }
> + /* obtain the T cold value */
> + cold = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + cold = (cold & temp_sensor->registers->threshold_tcold_mask)
> + >> __ffs(temp_sensor->registers->threshold_tcold_mask);
> +
> + /* obtain the T HOT value */
> + hot = omap_temp_sensor_readl(temp_sensor,
> + temp_sensor->registers->bgap_threshold);
> + hot = (hot & temp_sensor->registers->threshold_thot_mask) >>
> + __ffs(temp_sensor->registers->threshold_thot_mask);
> +
> + /* 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 current temperature is in-between the hot and cold thresholds
> + * Enable both masks or in the init case enable both masks
> + */
> + if ((temp > cold && temp < hot) || (set_cold && set_hot))
> + omap_temp_sensor_unmask_interrupts(temp_sensor, 1, 1);
> +
> + /*
> + * If user sets the HIGH threshold(t_hot) greater than the current
> + * temperature(temp) unmask the HOT interrupts
> + */
> + else if (hot > temp)
> + omap_temp_sensor_unmask_interrupts(temp_sensor, 1, 0);
> +
> + /*
> + * If user sets the LOW threshold(t_cold) lower than the current
> + * temperature(temp) unmask the COLD interrupts
> + */
> + else
> + omap_temp_sensor_unmask_interrupts(temp_sensor, 0, 1);
> +}
> +
> +/* 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);
> + 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 t_hot;
> +
> + if (strict_strtol(buf, 10, &val))
> + return -EINVAL;
> + if (val < MIN_TEMP - HYST_VAL)
> + return -EINVAL;
MIN_TEMP + HYST_VAL ?
> +
> + t_hot = temp_to_adc_conversion(val);
> + if (t_hot < 0)
> + return t_hot;
Difficuly to accomplish since t_hot is u32.
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + omap_temp_sensor_configure_thresholds_mask(temp_sensor, 1, 0,
> + t_hot, 0);
> + 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;
> +
> + 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");
> + return -EIO;
> + }
> +
> + temp = adc_to_temp_conversion(temp);
> +
adc_to_temp_conversion can return a negative value.
> + 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 t_cold;
> + long val;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
Just return -EINVAL.
> +
> + if (val > MAX_TEMP - HYST_VAL) {
> + count = -EINVAL;
> + goto out;
Just return -EINVAL here.
> + }
> +
> + t_cold = temp_to_adc_conversion(val);
> + if (t_cold < 0)
> + return t_cold;
> +
t_cold is u32 and will never be < 0. Wondering ... doesn't gcc complain about
this ?
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + omap_temp_sensor_configure_thresholds_mask(temp_sensor, 0, 1, 0,
> + t_cold);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> +out:
> + return count;
> +}
> +
> +static ssize_t show_update_interval(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct omap_temp_sensor *temp_sensor = dev_get_drvdata(dev);
> + u32 temp;
> +
> + 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 * 1000 / temp_sensor->clk_rate;
> +
> + return sprintf(buf, "%d\n", temp);
> +}
> +
> +static ssize_t set_update_interval(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;
> +
> + if (strict_strtol(buf, 10, &val)) {
> + count = -EINVAL;
> + goto out;
> + }
Just return -EINVAL.
> +
> + if (val < 0)
> + return -EINVAL;
If values < 0 are not valid, might as well use strict_strtoul() above.
> + val *= temp_sensor->clk_rate / 1000;
Divide happens first here. Loss of accuracy not a problem ?
Also, no max value, and 0 is ok ?
Large values may result in negative counter values if someone enters a large
number.
> + mutex_lock(&temp_sensor->sensor_mutex);
> + omap_configure_temp_sensor_counter(temp_sensor, val);
> + 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;
> +
> + 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)
> + return -EIO;
> +
> + temp = adc_to_temp[temp - OMAP_ADC_START_VALUE];
> +
Use adc_to_temp_conversion().
> + return sprintf(buf, "%d\n", temp);
return sprintf(buf, "%d\n", adc_to_temp_conversion(temp));
might be a bit simpler.
> +}
> +
> +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_interval, S_IWUSR | S_IRUGO,
> + show_update_interval, set_update_interval, 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_interval.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->pdev_dev, "clock already on\n");
> + goto out;
> + }
Can never happen.
> +
> + ret = pm_runtime_get_sync(temp_sensor->pdev_dev);
ret is u32.
> + if (ret < 0) {
> + dev_err(temp_sensor->pdev_dev, "get sync failed\n");
> + goto out;
return ret;
is just as good.
> + }
> +
> + temp_sensor->clk_on = 1;
> +
> +out:
> + return ret;
> +}
> +
> +static void omap_temp_sensor_clk_disable(struct omap_temp_sensor
> *temp_sensor)
> +{
> + /* Gate the clock */
> + pm_runtime_put_sync(temp_sensor->hwmon_dev);
> + temp_sensor->clk_on = 0;
This variable is quite useless.
> +}
> +
> +static irqreturn_t omap_talert_irq_handler(int irq, void *data)
> +{
> + struct omap_temp_sensor *temp_sensor;
> + int t_hot, t_cold, temp;
> +
Why int here ?
> + 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
> + */
Comment does not match the code.
> + 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);
> +
> + if (temp_sensor->hwmon_dev)
> + /* kobject_uvent to user space telling 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 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) {
> + dev_err(&pdev->dev, "Memory allocation failed\n");
> + return -ENOMEM;
> + }
> +
> + mutex_init(&temp_sensor->sensor_mutex);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&pdev->dev, "no mem resource\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->irq = platform_get_irq_byname(pdev, "thermal_alert");
> + if (temp_sensor->irq < 0) {
> + dev_err(&pdev->dev, "get_irq_byname failed\n");
> + ret = temp_sensor->irq;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->phy_base = ioremap(mem->start, resource_size(mem));
> + if (!temp_sensor->phy_base) {
> + dev_err(&pdev->dev, "ioremap failed\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
> + temp_sensor->clock = NULL;
> + temp_sensor->registers = pdata->registers;
> + temp_sensor->pdev_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))
> + dev_info(&pdev->dev,
> + "Invalid EFUSE, Non-trimmed BGAP, Temp not
> accurate\n");
> +
> + dev_set_drvdata(&pdev->dev, temp_sensor);
> + temp_sensor->clock = clk_get(&pdev->dev, "fck");
> + if (IS_ERR(temp_sensor->clock)) {
> + ret = PTR_ERR(temp_sensor->clock);
> + dev_err(&pdev->dev,
> + "unable to get fclk: %d\n", ret);
> + goto plat_res_err;
No iounmap in this case.
> + }
> +
> + ret = omap_temp_sensor_clk_enable(temp_sensor);
> + if (ret)
> + goto clken_err;
> +
> + clk_rate = clk_round_rate(temp_sensor->clock, max_freq);
> + if (clk_rate < min_freq || clk_rate == 0xffffffff) {
> + ret = -ENODEV;
> + 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 clk cycle */
> + 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);
> +
> + 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;
> + }
> +
> + 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;
> + }
> +
> + 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;
> + }
> +
> + mutex_lock(&temp_sensor->sensor_mutex);
> + omap_temp_sensor_configure_thresholds_mask(temp_sensor, 1, 1,
> + T_HOT, T_COLD);
> + mutex_unlock(&temp_sensor->sensor_mutex);
> +
> + return 0;
> +
> +hwmon_reg_err:
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
> + &omap_temp_sensor_group);
> +sysfs_create_err:
> + free_irq(temp_sensor->irq, temp_sensor);
> +req_irq_err:
> + omap_temp_sensor_clk_disable(temp_sensor);
> +clken_err:
> + clk_put(temp_sensor->clock);
> + iounmap(temp_sensor->phy_base);
> +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);
> + sysfs_remove_group(&temp_sensor->hwmon_dev->kobj,
Kind of odd to use hwmon_dev here, and not &pdev->dev.kobj.
> + &omap_temp_sensor_group);
> + free_irq(temp_sensor->irq, temp_sensor);
Sure you don't want to disable the interrupts before freeing the irq ?
> + omap_temp_sensor_clk_disable(temp_sensor);
> + clk_put(temp_sensor->clock);
> + iounmap(temp_sensor->phy_base);
> + 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-keer...@ti.com>");
> --
> 1.7.0.4
>
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