Re: [PATCH] thermal: Add msm tsens thermal sensor driver

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

Thankyou for sending the patch..
here are some comments

On 27/01/15 04:09, Narendran Rajan wrote:
...

> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/thermal.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/pm.h>
> +#include <linux/bitops.h>
> +#include <linux/regmap.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
??

> +#include <linux/of_platform.h>
???

> +#include <linux/io.h>
> +#include <linux/mfd/syscon.h>
> +
> +/* Trips: from very hot to very cold */
> +enum tsens_trip_type {
> +	TSENS_TRIP_STAGE3,
> +	TSENS_TRIP_STAGE2,
> +	TSENS_TRIP_STAGE1,
> +	TSENS_TRIP_STAGE0,
> +	TSENS_TRIP_NUM,
> +};
Do you need this if trips are actually coming from DT?

> +
> +#define TSENS_CAL_MDEGC				30000
> +
> +#define TSENS_MAX_SENSORS			11
> +
> +#define TSENS_8960_CONFIG_ADDR			0x3640
> +#define TSENS_8960_CONFIG			0x9b
> +#define TSENS_8960_CONFIG_MASK			0xf
> +
> +#define TSENS_CNTL_ADDR				0x3620
> +#define TSENS_CNTL_RESUME_MASK			0xfffffff9
> +#define TSENS_EN				BIT(0)
> +#define TSENS_SW_RST				BIT(1)
> +#define SENSOR0_EN				BIT(3)
> +#define TSENS_MIN_STATUS_MASK			BIT(0)
> +#define TSENS_LOWER_STATUS_CLR			BIT(1)
> +#define TSENS_UPPER_STATUS_CLR			BIT(2)
> +#define TSENS_MAX_STATUS_MASK			BIT(3)
> +#define TSENS_MEASURE_PERIOD			1
> +#define TSENS_8960_SLP_CLK_ENA			BIT(26)
> +#define TSENS_8660_SLP_CLK_ENA			BIT(24)
> +#define TSENS_8064_STATUS_CNTL			0x3660
> +
> +#define TSENS_THRESHOLD_ADDR			0x3624
> +#define TSENS_THRESHOLD_MAX_CODE		0xff
> +#define TSENS_THRESHOLD_MIN_CODE		0
> +#define TSENS_THRESHOLD_MAX_LIMIT_SHIFT		24
> +#define TSENS_THRESHOLD_MIN_LIMIT_SHIFT		16
> +#define TSENS_THRESHOLD_UPPER_LIMIT_SHIFT	8
> +#define TSENS_THRESHOLD_LOWER_LIMIT_SHIFT	0
> +
> +/* Initial temperature threshold values */
> +#define TSENS_LOWER_LIMIT_TH			0x50
> +#define TSENS_UPPER_LIMIT_TH			0xdf
> +#define TSENS_MIN_LIMIT_TH			0x0
> +#define TSENS_MAX_LIMIT_TH			0xff
> +
> +#define TSENS_S0_STATUS_ADDR			0x3628
> +
> +#define TSENS_INT_STATUS_ADDR			0x363c
> +#define TSENS_LOWER_INT_MASK			BIT(1)
> +#define TSENS_UPPER_INT_MASK			BIT(2)
> +#define TSENS_MAX_INT_MASK			BIT(3)
> +#define TSENS_TRDY_MASK				BIT(7)
> +
> +#define TSENS_SENSOR_SHIFT			16
> +#define TSENS_REDUND_SHIFT			24
> +#define TSENS_SENSOR0_SHIFT			3
> +
> +#define TSENS_8660_QFPROM_ADDR			0x00bc
?? Why is this offset defined in the driver, Is'nt this supposed to come 
via dt?
> +#define TSENS_8660_CONFIG			1
> +#define TSENS_8660_CONFIG_SHIFT			28
> +#define TSENS_8660_CONFIG_MASK			(3 << TSENS_8660_CONFIG_SHIFT)
> +
> +struct tsens_device;
> +
> +struct tsens_sensor {
> +	struct thermal_zone_device	*tz_dev;
> +	enum thermal_device_mode	mode;
> +	unsigned int			sensor_num;
> +	int				offset;
> +	u32				slope;
> +	struct tsens_device		*tmdev;
> +	u32                             status;
> +};
> +
> +struct tsens_device {
> +	bool			prev_reading_avail;
> +	unsigned int		num_sensors;
> +	int			pm_tsens_thr_data;
> +	int			pm_tsens_cntl;
> +	unsigned int            calib_offset;
> +	unsigned int            backup_calib_offset;
> +	struct work_struct	tsens_work;
> +	struct regmap		*map;
> +	struct regmap_field	*status_field;
> +	struct tsens_sensor	sensor[0];
> +};
> +
> +static struct device *tsens_dev;
Hmm.. I think you should remove this global variable and find a better 
way to get hold of this.

> +
> +/* Temperature on y axis and ADC-code on x-axis */
> +static int
> +tsens_tz_code_to_mdegC(u32 adc_code, const struct tsens_sensor *s)
> +{
> +	return adc_code * s->slope + s->offset;
> +}
> +
> +static int tsens_tz_get_temp(void *_sensor,
> +			     long *temp)
> +{
> +	const struct tsens_sensor *tm_sensor = _sensor;
> +	struct tsens_device *tmdev = tm_sensor->tmdev;
> +	u32 code, trdy;
> +
> +	if (tm_sensor->mode != THERMAL_DEVICE_ENABLED)
> +		return -EINVAL;
> +
> +	if (!tmdev->prev_reading_avail) {
> +		while (!regmap_read(tmdev->map, TSENS_INT_STATUS_ADDR, &trdy) &&
> +		       !(trdy & TSENS_TRDY_MASK))
> +			usleep_range(1000, 1100);
> +		tmdev->prev_reading_avail = true;
> +	}
> +
> +	regmap_read(tmdev->map, tm_sensor->status, &code);
> +	*temp = tsens_tz_code_to_mdegC(code, tm_sensor);
> +
> +	dev_dbg(tsens_dev, "Temperature for sensor %d is: %ld",
> +		tm_sensor->sensor_num, *temp);
> +
> +	return 0;
> +}
> +
> +/*
> + * If the main sensor is disabled all the sensors are disable and
> + * the clock is disabled.
> + * If the main sensor is disabled and a sub-sensor is enabled
> + * return with an error.
> + */
> +static int tsens_tz_set_mode(struct tsens_sensor *tm_sensor,
> +			      enum thermal_device_mode mode)
> +{
> +	struct tsens_device *tmdev = tm_sensor->tmdev;
> +	unsigned int i, n = tmdev->num_sensors;
> +	u32 reg, mask;
> +
> +	if (mode == tm_sensor->mode)
> +		return 0;
> +
> +	regmap_read(tmdev->map, TSENS_CNTL_ADDR, &reg);
> +
> +	mask = BIT(tm_sensor->sensor_num + TSENS_SENSOR0_SHIFT);
> +	if (mode == THERMAL_DEVICE_ENABLED) {
> +		if (!(reg & SENSOR0_EN) && mask != SENSOR0_EN) {
> +			pr_err("Main sensor not enabled\n");
> +			return -EINVAL;
> +		}
> +
> +		regmap_write(tmdev->map, TSENS_CNTL_ADDR, reg | TSENS_SW_RST);
> +		if (tmdev->num_sensors > 1)
> +			reg |= mask | TSENS_8960_SLP_CLK_ENA | TSENS_EN;
> +		else
> +			reg |= mask | TSENS_8660_SLP_CLK_ENA | TSENS_EN;
> +		tmdev->prev_reading_avail = false;
> +	} else {
> +		reg &= ~mask;
> +		if (!(reg & SENSOR0_EN)) {
> +			dev_warn(tsens_dev, "Main sensor not enabled. Disabling subsensors\n");
> +
> +			reg &= ~GENMASK(n + TSENS_SENSOR0_SHIFT - 1,
> +					TSENS_SENSOR0_SHIFT);
> +			reg &= ~TSENS_EN;
> +
> +			if (tmdev->num_sensors > 1)
> +				reg &= ~TSENS_8960_SLP_CLK_ENA;
> +			else
> +				reg &= ~TSENS_8660_SLP_CLK_ENA;
> +
> +			/* Disable all sub-sensors */
> +			for (i = 1; i < n; i++)
> +				tmdev->sensor[i].mode = mode;
> +		}
> +	}
> +
> +	regmap_write(tmdev->map, TSENS_CNTL_ADDR, reg);
> +	tm_sensor->mode = mode;
> +
> +	return 0;
> +}
> +
> +#ifdef THERMAL_TSENS8960_HWTRIPS

Should this be a kernel config?
  Or by default this should'nt be On?
Do you need this code if the trip values are actually coming from DT?

> +static int tsens_get_trip_temp(struct tsens_sensor *tm_sensor,
> +				   int trip, int *temp)
> +{
> +	struct tsens_device *tmdev = tm_sensor->tmdev;
> +	u32 reg;
> +
> +	regmap_read(tmdev->map, TSENS_THRESHOLD_ADDR, &reg);
> +	switch (trip) {
> +	case TSENS_TRIP_STAGE3:
> +		reg >>= TSENS_THRESHOLD_MAX_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE2:
> +		reg >>= TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE1:
> +		reg >>= TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE0:
> +		reg >>= TSENS_THRESHOLD_MIN_LIMIT_SHIFT;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +	reg &= TSENS_THRESHOLD_MAX_CODE;
> +
> +	temp = tsens_tz_code_to_mdegC(reg, tm_sensor);
> +
> +	dev_dbg(tsens_dev, "Sensor %d, trip %d temp is :%d",
> +		tm_sensor->sensor_num, trip, *temp);
> +
> +	return 0;
> +}
> +
> +static void tsens_print_trip_temp(struct tsens_sensor *tm_sensor)
> +{
> +	int temp;
> +
> +	tsens_get_trip_temp(tm_sensor, TSENS_TRIP_STAGE0, &temp);
> +	tsens_get_trip_temp(tm_sensor, TSENS_TRIP_STAGE1, &temp);
> +	tsens_get_trip_temp(tm_sensor, TSENS_TRIP_STAGE2, &temp);
> +	tsens_get_trip_temp(tm_sensor, TSENS_TRIP_STAGE3, &temp);
> +}
> +
> +static int tsens_tz_mdegC_to_code(int mdegC, const struct tsens_sensor *s)
> +{
> +	int code;
> +
> +	code = DIV_ROUND_CLOSEST(mdegC - s->offset, s->slope);
> +	return clamp(code, TSENS_THRESHOLD_MIN_CODE, TSENS_THRESHOLD_MAX_CODE);
> +}
> +
> +static u32 tsens_hi_code(int trip, u32 reg_cntl, u32 thresh)
> +{
> +	u32 hi_code;
> +
> +	switch (trip) {
> +	case TSENS_TRIP_STAGE0:
> +		if (!(reg_cntl & TSENS_LOWER_STATUS_CLR)) {
> +			hi_code = thresh >> TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE1:
> +		if (!(reg_cntl & TSENS_UPPER_STATUS_CLR)) {
> +			hi_code = thresh >> TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE2:
> +		if (!(reg_cntl & TSENS_MAX_STATUS_MASK)) {
> +			hi_code = thresh >> TSENS_THRESHOLD_MAX_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE3:
> +	default:
> +		hi_code = TSENS_THRESHOLD_MAX_CODE;
> +		break;
> +	}
> +
> +	return hi_code & TSENS_THRESHOLD_MAX_CODE;
> +}
> +
> +static u32 tsens_lo_code(int trip, u32 reg_cntl, u32 thresh)
> +{
> +	u32 lo_code;
> +
> +	switch (trip) {
> +	case TSENS_TRIP_STAGE3:
> +		if (!(reg_cntl & TSENS_UPPER_STATUS_CLR)) {
> +			lo_code = thresh >> TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE2:
> +		if (!(reg_cntl & TSENS_LOWER_STATUS_CLR)) {
> +			lo_code = thresh >> TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE1:
> +		if (!(reg_cntl & TSENS_MIN_STATUS_MASK)) {
> +			lo_code = thresh >> TSENS_THRESHOLD_MIN_LIMIT_SHIFT;
> +			break;
> +		}
> +		/* else fall through */
> +	case TSENS_TRIP_STAGE0:
> +	default:
> +		lo_code = TSENS_THRESHOLD_MIN_CODE;
> +		break;
> +	}
> +
> +	return lo_code & TSENS_THRESHOLD_MAX_CODE;
> +}
> +
> +static int tsens_tz_set_trip_temp(struct tsens_sensor *tm_sensor,
> +	int trip, unsigned long temp)
> +{
> +	struct tsens_device *tmdev = tm_sensor->tmdev;
> +	struct regmap_field *status = tmdev->status_field;
> +	u32 thresh, reg_cntl, mask = TSENS_THRESHOLD_MAX_CODE;
> +	u32 code, hi_code, lo_code, code_err_chk;
> +
> +	code_err_chk = code = tsens_tz_mdegC_to_code(temp, tm_sensor);
> +
> +	regmap_field_read(status, &reg_cntl);
> +	regmap_read(tmdev->map, TSENS_THRESHOLD_ADDR, &thresh);
> +
> +	switch (trip) {
> +	case TSENS_TRIP_STAGE3:
> +		code <<= TSENS_THRESHOLD_MAX_LIMIT_SHIFT;
> +		mask <<= TSENS_THRESHOLD_MAX_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE2:
> +		code <<= TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +		mask <<= TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE1:
> +		code <<= TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +		mask <<= TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +		break;
> +	case TSENS_TRIP_STAGE0:
> +		code <<= TSENS_THRESHOLD_MIN_LIMIT_SHIFT;
> +		mask <<= TSENS_THRESHOLD_MIN_LIMIT_SHIFT;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	hi_code = tsens_hi_code(trip, reg_cntl, thresh);
> +	lo_code = tsens_lo_code(trip, reg_cntl, thresh);
> +
> +	if (code_err_chk < lo_code || code_err_chk > hi_code)
> +		return -EINVAL;
> +
> +	regmap_update_bits(tmdev->map, TSENS_THRESHOLD_ADDR, mask, code);
> +
> +	return 0;
> +}
> +
> +static int tsens_set_trips(void *_sensor, long low, long high)
> +{
> +	struct tsens_sensor *tm_sensor = _sensor;
> +
> +	tsens_print_trip_temp(tm_sensor);
> +
> +	if (tsens_tz_set_trip_temp(tm_sensor, TSENS_TRIP_STAGE2, high))
> +		return -EINVAL;
> +
> +	if (tsens_tz_set_trip_temp(tm_sensor, TSENS_TRIP_STAGE1, low))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +#endif
> +
> +static void tsens_scheduler_fn(struct work_struct *work)
> +{
> +	struct tsens_device *tmdev;
> +	struct regmap_field *status;
> +	unsigned int threshold, threshold_low, i, code, bits, mask = 0;
> +	unsigned long sensor;
> +	bool upper_th_x, lower_th_x;
> +
> +	tmdev = container_of(work, struct tsens_device, tsens_work);
> +	status = tmdev->status_field;
> +
> +	regmap_field_update_bits(status,
> +			TSENS_LOWER_STATUS_CLR | TSENS_UPPER_STATUS_CLR,
> +			TSENS_LOWER_STATUS_CLR | TSENS_UPPER_STATUS_CLR);
> +
> +	regmap_read(tmdev->map, TSENS_THRESHOLD_ADDR, &threshold);
> +	threshold_low = threshold >> TSENS_THRESHOLD_LOWER_LIMIT_SHIFT;
> +	threshold_low &= TSENS_THRESHOLD_MAX_CODE;
> +	threshold = threshold >> TSENS_THRESHOLD_UPPER_LIMIT_SHIFT;
> +	threshold &= TSENS_THRESHOLD_MAX_CODE;
> +
> +	regmap_read(tmdev->map, TSENS_CNTL_ADDR, &bits);
> +	sensor = bits;
> +	sensor >>= TSENS_SENSOR0_SHIFT;
> +	for_each_set_bit(i, &sensor, tmdev->num_sensors) {
> +		regmap_read(tmdev->map, tmdev->sensor[i].status, &code);
> +		upper_th_x = code >= threshold;
> +		lower_th_x = code <= threshold_low;
> +
> +		if (upper_th_x)
> +			mask |= TSENS_UPPER_STATUS_CLR;
> +
> +		if (lower_th_x)
> +			mask |= TSENS_LOWER_STATUS_CLR;
> +
> +#ifdef THERMAL_TSENS8960_HWTRIPS
> +		if (upper_th_x || lower_th_x) {
> +			dev_info(tsens_dev,
> +				"Threshold reached for sensor(%d)\n", i);
> +			thermal_zone_device_update(tmdev->sensor[i].tz_dev);
> +		}
> +#endif
> +	}
> +
> +	regmap_field_update_bits(status,
> +			TSENS_UPPER_STATUS_CLR | TSENS_LOWER_STATUS_CLR, mask);
> +}
> +
> +static irqreturn_t tsens_isr(int irq, void *data)
> +{
> +	schedule_work(data);
> +	return IRQ_HANDLED;
> +}
> +
> +#ifdef CONFIG_PM
> +static int tsens_suspend(struct device *dev)
> +{
> +	int i;
> +	struct tsens_device *tmdev = dev_get_drvdata(dev);
> +	struct regmap *map = tmdev->map;
> +
> +	regmap_read(map, TSENS_THRESHOLD_ADDR, &tmdev->pm_tsens_thr_data);
> +	regmap_read(map, TSENS_CNTL_ADDR, &tmdev->pm_tsens_cntl);
> +	regmap_update_bits(map, TSENS_CNTL_ADDR,
> +			   TSENS_8960_SLP_CLK_ENA | TSENS_EN, 0);
> +
> +	tmdev->prev_reading_avail = 0;
> +	for (i = 0; i < tmdev->num_sensors; i++)
> +		tmdev->sensor[i].mode = THERMAL_DEVICE_DISABLED;
> +
> +	return 0;
> +}
> +
> +static int tsens_resume(struct device *dev)
> +{
> +	int i;
> +	unsigned long reg_cntl;
> +	struct tsens_device *tmdev = dev_get_drvdata(dev);
> +	struct regmap *map = tmdev->map;
> +
> +	regmap_update_bits(map, TSENS_CNTL_ADDR, TSENS_SW_RST, TSENS_SW_RST);
> +	regmap_field_update_bits(tmdev->status_field,
> +			TSENS_MIN_STATUS_MASK | TSENS_MAX_STATUS_MASK,
> +			TSENS_MIN_STATUS_MASK | TSENS_MAX_STATUS_MASK);
> +
> +	if (tmdev->num_sensors > 1)
> +		regmap_update_bits(map, TSENS_8960_CONFIG_ADDR,
> +				TSENS_8960_CONFIG_MASK,
> +				TSENS_8960_CONFIG);
> +
> +	regmap_write(map, TSENS_THRESHOLD_ADDR, tmdev->pm_tsens_thr_data);
> +	regmap_write(map, TSENS_CNTL_ADDR, tmdev->pm_tsens_cntl);
> +
> +	reg_cntl = tmdev->pm_tsens_cntl;
> +	reg_cntl >>= TSENS_SENSOR0_SHIFT;
> +	for_each_set_bit(i, &reg_cntl, tmdev->num_sensors)
> +		tmdev->sensor[i].mode = THERMAL_DEVICE_ENABLED;
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops tsens_pm_ops = {
> +	.suspend	= tsens_suspend,
> +	.resume		= tsens_resume,
> +};
> +#endif
> +
> +static void tsens_disable_mode(const struct tsens_device *tmdev)
> +{
> +	u32 reg_cntl;
> +	u32 mask;
> +
> +	mask = GENMASK(tmdev->num_sensors - 1, 0);
> +	mask <<= TSENS_SENSOR0_SHIFT;
> +	mask |= TSENS_EN;
> +
> +	regmap_read(tmdev->map, TSENS_CNTL_ADDR, &reg_cntl);
> +	reg_cntl &= ~mask;
> +	if (tmdev->num_sensors > 1)
> +		reg_cntl &= ~TSENS_8960_SLP_CLK_ENA;
> +	else
> +		reg_cntl &= ~TSENS_8660_SLP_CLK_ENA;
> +	regmap_write(tmdev->map, TSENS_CNTL_ADDR, reg_cntl);
> +}
> +
> +static void tsens_hw_init(struct tsens_device *tmdev)
> +{
> +	u32 reg_cntl, reg_thr;
> +
> +	reg_cntl = TSENS_SW_RST;
> +	regmap_update_bits(tmdev->map, TSENS_CNTL_ADDR, TSENS_SW_RST, reg_cntl);
> +
> +	if (tmdev->num_sensors > 1) {
> +		reg_cntl |= TSENS_8960_SLP_CLK_ENA |
> +			(TSENS_MEASURE_PERIOD << 18);

Can these magic shift values go some where in defines.?

> +		reg_cntl &= ~TSENS_SW_RST;
> +		regmap_update_bits(tmdev->map, TSENS_8960_CONFIG_ADDR,
> +				   TSENS_8960_CONFIG_MASK, TSENS_8960_CONFIG);
> +	} else {
> +		reg_cntl |= TSENS_8660_SLP_CLK_ENA |
> +			(TSENS_MEASURE_PERIOD << 16);
> +		reg_cntl &= ~TSENS_8660_CONFIG_MASK;
> +		reg_cntl |= TSENS_8660_CONFIG << TSENS_8660_CONFIG_SHIFT;
> +	}
> +
> +	reg_cntl |= GENMASK(tmdev->num_sensors - 1, 0) << TSENS_SENSOR0_SHIFT;
> +	regmap_write(tmdev->map, TSENS_CNTL_ADDR, reg_cntl);
> +
> +	regmap_field_update_bits(tmdev->status_field,
> +			TSENS_LOWER_STATUS_CLR | TSENS_UPPER_STATUS_CLR |
> +			TSENS_MIN_STATUS_MASK | TSENS_MAX_STATUS_MASK,
> +			TSENS_LOWER_STATUS_CLR | TSENS_UPPER_STATUS_CLR |
> +			TSENS_MIN_STATUS_MASK | TSENS_MAX_STATUS_MASK);
> +
> +	reg_cntl |= TSENS_EN;
> +	regmap_write(tmdev->map, TSENS_CNTL_ADDR, reg_cntl);
> +
> +	reg_thr = (TSENS_LOWER_LIMIT_TH << TSENS_THRESHOLD_LOWER_LIMIT_SHIFT) |
> +		(TSENS_UPPER_LIMIT_TH << TSENS_THRESHOLD_UPPER_LIMIT_SHIFT) |
> +		(TSENS_MIN_LIMIT_TH << TSENS_THRESHOLD_MIN_LIMIT_SHIFT) |
> +		(TSENS_MAX_LIMIT_TH << TSENS_THRESHOLD_MAX_LIMIT_SHIFT);
> +	regmap_write(tmdev->map, TSENS_THRESHOLD_ADDR, reg_thr);
> +}
> +
...

> +static int
> +tsens_calib_sensors8960(struct tsens_device *tmdev, struct regmap *map)
> +{
> +	int i;
> +	u32 temp_data[TSENS_MAX_SENSORS];
> +	u8 *byte_data;
> +	u32 fuse, redun, num_read;
> +	struct tsens_sensor *s = tmdev->sensor;
> +
> +	fuse = tmdev->calib_offset;
> +	redun = tmdev->backup_calib_offset;
> +
> +	/**
> +	* syscon regmap is 32-bit data, but calibration data is 8-bit.
> +	* read 4 bytes from regmap in a loop and then extract bytes seprately
> +	*/
> +
It looks like workaround for the problem in syscon driver.
Please use this patch to fix it.

--------------------->cut<----------------------
 From c50ea9c1ac61d73b1edcbc5469614cdc6655a38c Mon Sep 17 00:00:00 2001
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Date: Mon, 26 Jan 2015 07:30:25 +0000
Subject: [RFC PATCH 1/2] WIP: mfd: syscon: Add register stride to DT 
bindings.

This patch adds register stride to dt bindings so that the consumers of
the syscon could change it to there need. One of the the use case for
this feature is Qualcomm qfprom which needs a byte access to regmap
returned from syscon.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
  Documentation/devicetree/bindings/mfd/syscon.txt | 3 +++
  drivers/mfd/syscon.c                             | 9 +++++++++
  2 files changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt 
b/Documentation/devicetree/bindings/mfd/syscon.txt
index fe8150b..7f06ec1 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt
@@ -13,6 +13,9 @@ Required properties:
  - compatible: Should contain "syscon".
  - reg: the register region can be accessed from syscon

+Optional properties:
+- stride : register address stride in bytes.
+
  Examples:
  gpr: iomuxc-gpr@020e0000 {
  	compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 176bf0f..98769d5 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -48,6 +48,7 @@ static struct syscon *of_syscon_register(struct 
device_node *np)
  	struct regmap *regmap;
  	void __iomem *base;
  	int ret;
+	u32 stride;
  	struct regmap_config syscon_config = syscon_regmap_config;

  	if (!of_device_is_compatible(np, "syscon"))
@@ -69,6 +70,14 @@ static struct syscon *of_syscon_register(struct 
device_node *np)
  	 else if (of_property_read_bool(np, "little-endian"))
  		syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;

+	if (!of_property_read_u32(np, "stride", &stride)) {
+		if (stride > 4)
+			stride = 4;
+
+		syscon_config.reg_stride = stride;
+		syscon_config.val_bits = 8 * stride;
+	}
+
  	regmap = regmap_init_mmio(NULL, base, &syscon_config);
  	if (IS_ERR(regmap)) {
  		pr_err("regmap init failed\n");
-- 
1.9.1

--------------------->cut<----------------------
> +	num_read = DIV_ROUND_UP(tmdev->num_sensors, 4);
> +
> +	for (i = 0; i < num_read; i++) {
> +		if (regmap_read(map, (redun + i*4), &temp_data[i]))
> +			return -EINVAL;
> +
> +		if (!temp_data[i]) {
> +			dev_dbg(tsens_dev, "Main calib data not valid\n");
> +			if (regmap_read(map, (fuse + i*4), &temp_data[i]))
> +				return -EINVAL;
> +		}
> +	}
> +
> +	byte_data = (u8 *)temp_data;
> +
> +	for (i = 0; i < tmdev->num_sensors; i++, s++) {
> +		s->offset = TSENS_CAL_MDEGC - s->slope * byte_data[i];
> +		dev_dbg(tsens_dev, "calib data %d is %c", i, byte_data[i]);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops tsens_thermal_of_ops = {
> +	.get_temp = tsens_tz_get_temp,
> +};
> +
> +
> +static int tsens_register(struct tsens_device *tmdev, int i)
> +{
> +	char name[18];
> +	u32 addr = TSENS_S0_STATUS_ADDR;
> +	struct tsens_sensor *s = &tmdev->sensor[i];
> +
> +	/*
> +	* The status registers for each sensor are discontiguous
> +	* because some SoCs have 5 sensors while others have more
> +	* but the control registers stay in the same place, i.e.
> +	* directly after the first 5 status registers.
> +	*/
> +	if (i >= 5)
> +		addr += 40;

This magic values should be going in to some descriptive constants..

> +
> +	addr += i * 4;
> +
> +	snprintf(name, sizeof(name), "tsens_tz_sensor%d", i);
Hmm where is the name actually used??

> +	s->mode = THERMAL_DEVICE_ENABLED;
> +	s->sensor_num = i;
> +	s->status = addr;
> +	s->tmdev = tmdev;
> +	s->tz_dev = thermal_zone_of_sensor_register(tsens_dev, i, s,
> +						&tsens_thermal_of_ops);
> +
> +	if (IS_ERR(s->tz_dev))
> +		return -ENODEV;
So does that mean that driver would not register tsens unless there is a 
DT node for it?
For apq8064 which has 11 sensors, its becomes necessary to add all 11 
sensors in DT with trip points and cooling devices. Which IMO is not right.
You could probably do something like:

	s->tz_dev = thermal_zone_of_sensor_register(tsens_dev, i, s,
					&tsens_thermal_of_ops);

	if (IS_ERR(s->tz_dev)) {
		s->tz_dev = thermal_zone_device_register( ... )
		if (IS_ERR(s->tz_dev))
			return -ENODEV;
	}

same thing in faliure/remove case ..

> +
> +	return 0;
> +}
> +
> +static int tsens_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct device_node *base_node;
> +	struct platform_device *base_pdev;
> +	int ret, i, irq, num;
> +	struct tsens_sensor *s;
> +	struct tsens_device *tmdev;
> +	struct regmap *map, *imem_regmap;
> +	struct reg_field *field;
> +	static struct reg_field status_0 = {
> +		.reg = TSENS_8064_STATUS_CNTL,
> +		.lsb = 0,
> +		.msb = 3,
> +	};
> +	static struct reg_field status_8 = {
> +		.reg = TSENS_CNTL_ADDR,
> +		.lsb = 8,
> +		.msb = 11,
> +	};
> +
> +	tsens_dev = &pdev->dev;
> +
> +	num = of_property_count_u32_elems(np, "qcom,tsens-slopes");
> +	if (num <= 0) {
> +		dev_err(tsens_dev, "invalid tsens slopes\n");
> +		return -EINVAL;
> +	}
> +
> +	tmdev = devm_kzalloc(tsens_dev, sizeof(*tmdev) +
> +			     num * sizeof(struct tsens_sensor), GFP_KERNEL);
> +	if (tmdev == NULL)
> +		return -ENOMEM;
> +
> +	tmdev->num_sensors = num;
> +	for (i = 0, s = tmdev->sensor; i < num; i++, s++)
> +		of_property_read_u32_index(np, "qcom,tsens-slopes", i,
> +					   &s->slope);
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(tsens_dev,  "no irq resource?\n");
> +		return  -EINVAL;
> +	}
> +
> +	ret = of_property_read_u32_index(np, "qcom,calib-offsets", 0,
> +					   &tmdev->calib_offset);
> +	if (ret != 0) {
> +		dev_err(tsens_dev,  "No calibration offset set\n");
> +		return  -EINVAL;
> +	}
> +
> +	ret = of_property_read_u32_index(np, "qcom,calib-offsets", 1,
> +					   &tmdev->backup_calib_offset);
> +	if (ret) {
> +		dev_info(tsens_dev, "Missing backup calibration offset\n");
> +		tmdev->backup_calib_offset = tmdev->calib_offset;
> +	}
> +
> +	imem_regmap = syscon_regmap_lookup_by_phandle(np, "qcom,imem");
> +	if (IS_ERR(imem_regmap)) {
> +		dev_err(tsens_dev, "syscon regmap look up error\n");
> +		return PTR_ERR(imem_regmap);
> +	}
> +
Please see my comments in the bindings patch.

> +	if (num == 1)
> +		ret = tsens_calib_sensors8660(tmdev, imem_regmap);
> +	else
> +		ret = tsens_calib_sensors8960(tmdev, imem_regmap);
> +
> +	if (ret < 0) {
> +		dev_err(tsens_dev, "tsense calibration failed\n");
> +		return ret;
> +	}
> +
> +	base_node = of_parse_phandle(np, "qcom,tsens-base", 0);
> +	if (base_node == NULL) {
> +		dev_err(tsens_dev, "no base node present\n");
> +		return  -EINVAL;
> +	}
> +
> +	base_pdev = of_find_device_by_node(base_node);
> +	if (base_pdev == NULL) {
> +		dev_err(tsens_dev, "no base pdev node\n");
> +		return  -ENODEV;
> +	}
> +
> +	tmdev->map = map = dev_get_regmap(&base_pdev->dev, NULL);
> +	if (map == NULL) {
> +		dev_err(tsens_dev, "base regmap get failed\n");
> +		return  -ENODEV;
> +	}
> +
> +	/* Status bits move when the sensor bits next to them overlap */
> +	if (num > 5)
> +		field = &status_0;
> +	else
> +		field = &status_8;
> +
> +	tmdev->status_field = devm_regmap_field_alloc(tsens_dev, map, *field);
> +	if (IS_ERR(tmdev->status_field)) {
> +		dev_err(tsens_dev, "regmap alloc failed\n");
> +		return PTR_ERR(tmdev->status_field);
> +	}
> +
> +	tsens_hw_init(tmdev);
> +
> +	/*
> +	 * Register sensor 0 separately. This sensor is always
> +	 * expected to be present and if this fails, thermal
> +	 * sensor probe would fail
> +	 * Other sensors are optional and if registration fails
> +	 * disable the sensor and continue
> +	*/
> +	ret = tsens_register(tmdev, 0);
> +	if (ret < 0) {
> +		dev_err(tsens_dev, "Registering failed for primary sensor");
> +		ret = -ENODEV;
> +		goto fail;
> +	} else {
> +		tsens_tz_set_mode(&tmdev->sensor[0], THERMAL_DEVICE_ENABLED);
> +	}
> +
> +	for (i = 1;  i < tmdev->num_sensors; i++) {
> +		ret = tsens_register(tmdev, i);
> +
> +		if (ret < 0) {
> +			dev_err(tsens_dev,
> +				"Registering failed. Sensor(%i), disabled", i);
> +			tsens_tz_set_mode(&tmdev->sensor[i],
> +				THERMAL_DEVICE_DISABLED);
> +		} else {
> +			tsens_tz_set_mode(&tmdev->sensor[i],
> +				THERMAL_DEVICE_ENABLED);
> +		}
> +	}
> +
> +	INIT_WORK(&tmdev->tsens_work, tsens_scheduler_fn);
> +
> +	ret = devm_request_irq(tsens_dev, irq, tsens_isr, IRQF_TRIGGER_RISING,
> +			       "tsens", &tmdev->tsens_work);
Unless I missing something,...Would it actually get an interrupt without 
setting the proper trip values in the hw? For example in this driver we 
only register from DT.. and the values from Dt never ends up writing 
into the hw registers.. so this would never trigger an interrupt from 
trip points mentioned in DT. Unless the default reg values makes sense.. 
still its out of sync from DT trip values.

Does the interrupt actually work? Last time when I tested it on 3.4 It 
never did work?..
> +	if (ret < 0)
> +		goto err_irq;
> +
> +	platform_set_drvdata(pdev, tmdev);
> +
> +	dev_info(tsens_dev, "Tsens driver initialized\n");
> +
> +	return 0;
> +err_irq:
> +	for (i = 0, s = tmdev->sensor; i < tmdev->num_sensors; i++, s++)
> +		thermal_zone_of_sensor_unregister(&pdev->dev, s->tz_dev);
> +fail:
> +	tsens_disable_mode(tmdev);
> +	return ret;
> +}
> +
> +static int tsens_remove(struct platform_device *pdev)
> +{
> +	int i;
> +	struct tsens_sensor *s;
> +	struct tsens_device *tmdev = platform_get_drvdata(pdev);
> +
> +	tsens_disable_mode(tmdev);
> +	for (i = 0, s = tmdev->sensor; i < tmdev->num_sensors; i++, s++)
> +		thermal_zone_device_unregister(s->tz_dev);
> +
> +	return 0;
> +}
> +
> +static struct of_device_id tsens_match_table[] = {
> +	{.compatible = "qcom,ipq806x-tsens"},
should be "qcom,msm8960-tsens"

> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, tsens_match_table);
> +
> +static struct platform_driver tsens_driver = {
> +	.probe = tsens_probe,
> +	.remove = tsens_remove,
> +	.driver = {
> +		.of_match_table = tsens_match_table,
> +		.name = "tsens8960-thermal",
> +		.owner = THIS_MODULE,
remove the owner as it would be set anyway byt the core.
> +#ifdef CONFIG_PM
> +		.pm	= &tsens_pm_ops,
> +#endif
Please use SIMPLE_DEV_PM_OPS(...)

> +	},
> +};
> +module_platform_driver(tsens_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Temperature Sensor driver");
> +MODULE_ALIAS("platform:tsens8960-tm");
>
--srini