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@xxxxxx> > Cc: Jean Delvare <khali@xxxxxxxxxxxx> > Cc: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> > Cc: lm-sensors@xxxxxxxxxxxxxx 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 ? > +Author: > + J Keerthy <j-keerthy@xxxxxx> > + > +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/ > +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@xxxxxx> > + * Author: Moiz Sonasath <m-sonasath@xxxxxx> > + * > + * 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. > > + -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 ( ) > +} > + > +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. > +{ > + 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. > + } > + > + 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. > + } > + > + t_hot = temp_to_adc_conversion(val); Bad error return check. Negative on error. Should be if (t_hot < 0) return t_hot; > + if ((t_hot < OMAP_ADC_START_VALUE || t_hot > OMAP_ADC_END_VALUE)) { Unnecessary (( )) > + count = -EINVAL; > + goto out; This will try to release the not-acquired lock. > + } > + > + 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. > + } > + > + /* 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 ? > + } > + /* > + * 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. > + 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. 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". > + } > + > + 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. > + } > + > + t_cold = temp_to_adc_conversion(val); Bad error return check; same as above. > + 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. > + > +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. > + > + 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. > + 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. > + 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. It would make sense to call omap_configure_temp_sensor_counter() instead of duplicating the set functionality. > + 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. > + 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. > + 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. > +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. > +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 ? > +{ > + 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 ? > + } > + > + /* 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. > +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 ? > + 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. > + 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. > + dev_dbg(temp_sensor->hwmon_dev, > + "Invalid EFUSE, Non-trimmed BGAP, Temp not accurate\n"); dev_info might be better here. > + } > + > + 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. > + 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. The error log doesn't really provide anything useful to the administrator. Either add parameters, or drop it. > + 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. > + > + /* 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. > + 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 ? > + 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: * 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 ? > + 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. > + 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@xxxxxx>"); > -- > 1.7.0.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
