Message-ID: <523A06EE.9090801@ti.com>
Date:	Wed, 18 Sep 2013 16:02:54 -0400
From:	Eduardo Valentin <eduardo.valentin@...com>
To:	Ajit Pal Singh <ajitpal.singh@...com>
CC:	<rui.zhang@...el.com>, <eduardo.valentin@...com>,
	<linux-pm@...r.kernel.org>, <grant.likely@...aro.org>,
	<devicetree@...r.kernel.org>, <linux-doc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <rob@...dley.net>,
	Stephen Gallimore <stephen.gallimore@...com>,
	Srinivas Kandagatla <srinivas.kandagatla@...com>
Subject: Re: [PATCH] thermal: st: Add support for STiH41x thermal sensors

On 18-09-2013 05:38, Ajit Pal Singh wrote:
> Adds support for thermal sensors on STiH41x series SOCs.
> Single trip point 'THERMAL_TRIP_CRITICAL' is supported.
> STIH416 MPE sensor supports interrupt reporting when a preset
> threshold temperature is crossed.
> For rest of the thermal sensors a polling delay of 10000ms is
> set.
> 
> CC: Stephen Gallimore <stephen.gallimore@...com>
> CC: Srinivas Kandagatla <srinivas.kandagatla@...com>
> Signed-off-by: Ajit Pal Singh <ajitpal.singh@...com>
> ---
>  .../devicetree/bindings/thermal/st-thermal.txt     |   22 +
>  drivers/thermal/Kconfig                            |   11 +
>  drivers/thermal/Makefile                           |    1 +
>  drivers/thermal/st_thermal.c                       |  633 ++++++++++++++++++++
>  4 files changed, 667 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/st-thermal.txt
>  create mode 100644 drivers/thermal/st_thermal.c
> 
> diff --git a/Documentation/devicetree/bindings/thermal/st-thermal.txt b/Documentation/devicetree/bindings/thermal/st-thermal.txt
> new file mode 100644
> index 0000000..f127044
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/st-thermal.txt
> @@ -0,0 +1,22 @@
> +Binding for Thermal sensor driver for STMicroelectronics STiH41x series of SoCs.
> +
> +Required parameters:
> +1) compatible : st,<SoC>-<module>-thermal
> +		Should be one of "st,stih415-sas-thermal", "st,stih415-mpe-thermal",
> +		"st,stih416-sas-thermal" or "st,stih416-mpe-thermal" according to the
> +		SoC type (stih415 or stih416) and module type (sas or mpe).
> +2) st,syscfg : 	Should be a phandle of the syscfg node.
> +3) clocks: 	phandle of the clock used by the thermal sensor according to the common
> +		clock binding: Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Optional:
> +1) interrupts:	Standard way to define interrupt number.
> +		refer: Documentation/devicetree/bindings/resource-names.txt
> +		Interrupt is mandatory to be defined when compatible is stih416-mpe-thermal.
> +
> +Example:
> +temp0{
> +	compatible      = "st,stih416-sas-thermal";
> +	st,syscfg       = <&syscfg_front>;
> +	clocks          = <&CLOCKGEN_C_VCC 14>;
> +}
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index e988c81..158b4d8 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -180,6 +180,17 @@ config X86_PKG_TEMP_THERMAL
>  	  two trip points which can be set by user to get notifications via thermal
>  	  notification methods.
>  
> +config ST_THERMAL
> +	tristate "Thermal sensors on STMicroelectronics STiH41x series of SoCs"
> +	depends on ARCH_STI
> +	depends on OF
> +	default y
> +	help
> +	  Support for thermal sensors on STMicroelectronics STiH41x series of
> +	  SoCs. STiH415 and STiH416 SoCs have 2 thermal sensors each, one on the
> +	  SAS and second on the MPE module. STiH416 MPE thermal sensor supports
> +	  interrupt reporting when a preset thermal threshold is crossed.
> +
>  menu "Texas Instruments thermal drivers"
>  source "drivers/thermal/ti-soc-thermal/Kconfig"
>  endmenu
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 67184a2..d0a4c86 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -25,3 +25,4 @@ obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
>  obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
>  obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
>  obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
> +obj-$(CONFIG_ST_THERMAL)	+= st_thermal.o
> diff --git a/drivers/thermal/st_thermal.c b/drivers/thermal/st_thermal.c
> new file mode 100644
> index 0000000..8645a9c
> --- /dev/null
> +++ b/drivers/thermal/st_thermal.c
> @@ -0,0 +1,633 @@
> +/*
> + * st_thermal.c: ST Thermal Sensor Driver for STIH41x series of SoCs
> + * Author: Ajit Pal Singh <ajitpal.singh@...com>
> + *
> + * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/thermal.h>
> +
> +#define DRIVER_NAME "st-thermal"
> +
> +/* Regfield IDs */
> +enum {
> +	/*
> +	 * The PWR and INTerrupt threshold regfields
> +	 * share the same index as they are mutually exclusive
> +	 */
> +	TEMP_PWR = 0, INT_THRESH_HI = 0,
> +	DCORRECT	= 1,
> +	OVERFLOW	= 2,
> +	DATA		= 3,
> +	INT_ENABLE	= 4,
> +	/* keep last */
> +	MAX_REGFIELDS
> +};
> +
> +/* Thermal sensor power states */
> +enum st_thermal_power_state {
> +	POWER_OFF = 0,
> +	POWER_ON = 1
> +};
> +
> +struct st_thermal_sensor;
> +
> +struct st_thermal_sensor_ops {
> +	/* Power control */
> +	int (*power_ctrl)(struct st_thermal_sensor *,
> +		enum st_thermal_power_state);
> +	/* Adjust the temperature read from the sensor */
> +	unsigned int (*adjust_temp)(struct st_thermal_sensor *,
> +		unsigned int);
> +	/* Allocate regfields specific for this sensor */
> +	int (*alloc_regfields)(struct st_thermal_sensor *);
> +	int (*register_irq)(struct st_thermal_sensor *);
> +	int (*enable_irq)(struct st_thermal_sensor *);
> +};
> +
> +struct st_thermal_compat_data {
> +	const struct reg_field *reg_fields;
> +	struct st_thermal_sensor_ops *ops;
> +	unsigned int calibration_val;
> +	int temp_adjust_val;
> +	int crit_temp;
> +};
> +
> +struct st_thermal_sensor {
> +	struct platform_device *pdev;
> +	struct thermal_zone_device *th_dev;
> +	struct st_thermal_sensor_ops *ops;
> +	const struct st_thermal_compat_data *data;
> +	struct clk *clk;
> +	struct regmap *regmap;
> +	struct regmap_field *pwr;
> +	struct regmap_field *dcorrect;
> +	struct regmap_field *overflow;
> +	struct regmap_field *temp_data;
> +	struct regmap_field *int_thresh_hi;
> +	struct regmap_field *int_enable;
> +	unsigned int irq;
> +};
> +
> +/* Helper macros */
> +#define thzone_to_sensor(th)			((th)->devdata)
> +#define sensor_to_dev(sensor)			(&(sensor)->pdev->dev)
> +
> +/* STiH415 */
> +#define STIH415_SYSCFG_FRONT(num)		((num - 100)*4)
> +#define STIH415_SYSCFG_MPE(num)			((num - 600)*4)
> +
> +#define STIH415_SAS_THSENS_CONF			STIH415_SYSCFG_FRONT(178)
> +#define STIH415_SAS_THSENS_STATUS		STIH415_SYSCFG_FRONT(198)
> +#define STIH415_MPE_THSENS_CONF			STIH415_SYSCFG_MPE(607)
> +#define STIH415_MPE_THSENS_STATUS		STIH415_SYSCFG_MPE(667)
> +
> +/* STiH416 */
> +#define STIH416_SYSCFG_FRONT(num)		((num - 1000)*4)
> +#define STIH416_SYSCFG_THSENS(num)		(num*4)
> +
> +#define STIH416_SAS_THSENS_CONF			STIH416_SYSCFG_FRONT(1552)
> +#define STIH416_SAS_THSENS_STATUS1		STIH416_SYSCFG_FRONT(1554)
> +#define STIH416_SAS_THSENS_STATUS2		STIH416_SYSCFG_FRONT(1594)
> +#define STIH416_MPE_THSENS_CONF			STIH416_SYSCFG_THSENS(0)
> +#define STIH416_MPE_THSENS_STATUS		STIH416_SYSCFG_THSENS(1)
> +#define STIH416_MPE_THSENS_INT_THRESH		STIH416_SYSCFG_THSENS(2)
> +#define STIH416_MPE_THSENS_INT_EN		STIH416_SYSCFG_THSENS(3)
> +
> +/* STiH416_MPE power control bits */
> +#define STIH416_MPE_PDN				BIT(4)
> +#define STIH416_MPE_SRSTN			BIT(10)
> +
> +#define mcelsius(temp)				((temp) * 1000)
> +
> +static const struct reg_field st_415sas_regfields[MAX_REGFIELDS] = {
> +	[TEMP_PWR] = REG_FIELD(STIH415_SAS_THSENS_CONF, 9, 9),
> +	[DCORRECT] = REG_FIELD(STIH415_SAS_THSENS_CONF, 4, 8),
> +	[OVERFLOW] = REG_FIELD(STIH415_SAS_THSENS_STATUS, 9, 9),
> +	[DATA] = REG_FIELD(STIH415_SAS_THSENS_STATUS, 11, 18),
> +};
> +
> +static const struct reg_field st_415mpe_regfields[MAX_REGFIELDS] = {
> +	[TEMP_PWR] = REG_FIELD(STIH415_MPE_THSENS_CONF, 8, 8),
> +	[DCORRECT] = REG_FIELD(STIH415_MPE_THSENS_CONF, 3, 7),
> +	[OVERFLOW] = REG_FIELD(STIH415_MPE_THSENS_STATUS, 9, 9),
> +	[DATA] = REG_FIELD(STIH415_MPE_THSENS_STATUS, 11, 18),
> +};
> +
> +static const struct reg_field st_416sas_regfields[MAX_REGFIELDS] = {
> +	[TEMP_PWR] = REG_FIELD(STIH416_SAS_THSENS_CONF, 9, 9),
> +	[DCORRECT] = REG_FIELD(STIH416_SAS_THSENS_CONF, 4, 8),
> +	[OVERFLOW] = REG_FIELD(STIH416_SAS_THSENS_STATUS1, 8, 8),
> +	[DATA] = REG_FIELD(STIH416_SAS_THSENS_STATUS2, 10, 16),
> +};
> +
> +static const struct reg_field st_416mpe_regfields[MAX_REGFIELDS] = {
> +	/*
> +	 * According to the STIH416 MPE temp sensor data sheet -
> +	 * the PDN (Power Down Bit) and SRSTN (Soft Reset Bit) need to be
> +	 * written simultaneously for powering on and off the temperature
> +	 * sensor. regmap_update_bits() will be used to update the register.
> +	 */
> +	[INT_THRESH_HI] = REG_FIELD(STIH416_MPE_THSENS_INT_THRESH, 0, 7),
> +	[DCORRECT] = REG_FIELD(STIH416_MPE_THSENS_CONF, 5, 9),
> +	[OVERFLOW] = REG_FIELD(STIH416_MPE_THSENS_STATUS, 9, 9),
> +	[DATA] = REG_FIELD(STIH416_MPE_THSENS_STATUS, 11, 18),
> +	[INT_ENABLE] = REG_FIELD(STIH416_MPE_THSENS_INT_EN, 0, 0),
> +};
> +
> +static irqreturn_t st_thermal_thresh_int(int irq, void *data)
> +{
> +	struct st_thermal_sensor *sensor = data;
> +	struct device *dev = sensor_to_dev(sensor);
> +
> +	dev_dbg(dev, "%s,called\n", __func__);
> +	thermal_zone_device_update(sensor->th_dev);

Are you sure you want to do this here? The above call might sleep.

> +	return IRQ_HANDLED;
> +}
> +
> +static int st_thermal_alloc_common_regfields(struct st_thermal_sensor *sensor)
> +{
> +	struct device *dev = sensor_to_dev(sensor);
> +	struct regmap *regmap = sensor->regmap;
> +	const struct reg_field *reg_fields = sensor->data->reg_fields;
> +
> +	sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
> +					reg_fields[DCORRECT]);
> +
> +	sensor->overflow = devm_regmap_field_alloc(dev, regmap,
> +					reg_fields[OVERFLOW]);
> +
> +	sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
> +					reg_fields[DATA]);
> +
> +	if (IS_ERR(sensor->dcorrect) || IS_ERR(sensor->overflow) ||
> +	    IS_ERR(sensor->temp_data)) {
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +/* Private ops for STIH415 SAS,MPE & STIH416 SAS sensor modules */
> +static int st_power_ctrl(struct st_thermal_sensor *sensor,
> +			enum st_thermal_power_state power_state)
> +{
> +	return regmap_field_write(sensor->pwr, power_state);
> +}
> +
> +static unsigned int st_adjust_temp(struct st_thermal_sensor *sensor,
> +				unsigned int raw_temp)
> +{
> +	return raw_temp + sensor->data->temp_adjust_val;
> +}
> +
> +static int st_alloc_regfields(struct st_thermal_sensor *sensor)
> +{
> +	struct device *dev = sensor_to_dev(sensor);
> +	int ret;
> +
> +	ret = st_thermal_alloc_common_regfields(sensor);
> +	if (ret)
> +		return ret;
> +
> +	sensor->pwr = devm_regmap_field_alloc(dev, sensor->regmap,
> +				sensor->data->reg_fields[TEMP_PWR]);
> +	if (IS_ERR(sensor->pwr)) {
> +		dev_err(dev, "%s,failed to alloc reg field\n", __func__);
> +		return PTR_ERR(sensor->
>pwr);
> +	}
> +	return 0;
> +}
> +
> +static struct st_thermal_sensor_ops st_sensor_ops = {
> +	.power_ctrl = st_power_ctrl,
> +	.adjust_temp = st_adjust_temp,
> +	.alloc_regfields = st_alloc_regfields,
> +};
> +
> +/* Private ops for the STIH416 MPE sensor module */
> +static int st_416mpe_power_ctrl(struct st_thermal_sensor *sensor,
> +				enum st_thermal_power_state power_state)
> +{
> +	const unsigned int mask = (STIH416_MPE_PDN | STIH416_MPE_SRSTN);
> +	const unsigned int val = power_state ? mask : 0;
> +	return regmap_update_bits(sensor->regmap, STIH416_MPE_THSENS_CONF,
> +				  mask, val);
> +}
> +
> +static unsigned int st_416mpe_adjust_temp(struct st_thermal_sensor *sensor,
> +					unsigned int raw_temp)
> +{
> +	return raw_temp - sensor->data->temp_adjust_val;
> +}
> +
> +static int st_416mpe_alloc_regfields(struct st_thermal_sensor *sensor)
> +{
> +	struct device *dev = sensor_to_dev(sensor);
> +	struct regmap *regmap = sensor->regmap;
> +	const struct reg_field *reg_fields = sensor->data->reg_fields;
> +	int ret;
> +
> +	ret = st_thermal_alloc_common_regfields(sensor);
> +	if (ret)
> +		return ret;
> +
> +	sensor->int_thresh_hi = devm_regmap_field_alloc(dev, regmap,
> +					reg_fields[INT_THRESH_HI]);
> +	sensor->int_enable = devm_regmap_field_alloc(dev, regmap,
> +					reg_fields[INT_ENABLE]);
> +	if (IS_ERR(sensor->int_thresh_hi) || IS_ERR(sensor->int_enable)) {
> +		dev_err(dev, "%s,failed to alloc reg field(s)\n", __func__);
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static int st_416mpe_register_irq(struct st_thermal_sensor *sensor)
> +{
> +	struct platform_device *pdev = sensor->pdev;
> +	struct device *dev = sensor_to_dev(sensor);
> +	int ret;
> +
> +	sensor->irq = platform_get_irq(pdev, 0);
> +	if (sensor->irq < 0)
> +		return sensor->irq;
> +
> +	ret = devm_request_threaded_irq(dev, sensor->irq,
> +					NULL, st_thermal_thresh_int,
> +					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> +					DRIVER_NAME, sensor);
> +	if (ret) {
> +		dev_err(dev, "IRQ %d register failed\n", sensor->irq);
> +		return ret;
> +	}
> +	return sensor->ops->enable_irq(sensor);
> +}
> +
> +static int st_416mpe_enable_irq(struct st_thermal_sensor *sensor)
> +{
> +	int ret;
> +
> +	/* Set upper critical threshold */
> +	ret = regmap_field_write(sensor->int_thresh_hi, sensor->data->crit_temp
> +			 + sensor->data->temp_adjust_val);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_field_write(sensor->int_enable, 1);
> +}
> +
> +static struct st_thermal_sensor_ops st_416mpe_sensor_ops = {
> +	.power_ctrl = st_416mpe_power_ctrl,
> +	.adjust_temp = st_416mpe_adjust_temp,
> +	.alloc_regfields = st_416mpe_alloc_regfields,
> +	.register_irq = st_416mpe_register_irq,
> +	.enable_irq = st_416mpe_enable_irq,
> +};
> +
> +/* Compatible device data for stih415 sas thermal sensor */
> +static struct st_thermal_compat_data st_415sas_data = {
> +	.reg_fields = &st_415sas_regfields[0],
> +	.ops = &st_sensor_ops,
> +	.calibration_val = 16,
> +	.temp_adjust_val = 20,
> +	.crit_temp = 120,
> +};
> +
> +/* Compatible device data for stih415 mpe thermal sensor */
> +static struct st_thermal_compat_data st_415mpe_data = {
> +	.reg_fields = &st_415mpe_regfields[0],
> +	.ops = &st_sensor_ops,
> +	.calibration_val = 16,
> +	.temp_adjust_val = 20,
> +	.crit_temp = 120,
> +};
> +
> +/* Compatible device data for stih416 sas thermal sensor */
> +static struct st_thermal_compat_data st_416sas_data = {
> +	.reg_fields = &st_416sas_regfields[0],
> +	.ops = &st_sensor_ops,
> +	.calibration_val = 16,
> +	.temp_adjust_val = 20,
> +	.crit_temp = 120,
> +};
> +
> +/* Compatible device data stih416 mpe thermal sensor */
> +static struct st_thermal_compat_data st_416mpe_data = {
> +	.reg_fields = &st_416mpe_regfields[0],
> +	.ops = &st_416mpe_sensor_ops,
> +	.calibration_val = 24,
> +	.temp_adjust_val = 103,
> +	.crit_temp = 120,
> +};
> +
> +static struct of_device_id st_thermal_of_match[] = {
> +	{ .compatible = "st,stih415-sas-thermal",
> +		.data = &st_415sas_data },
> +	{ .compatible = "st,stih415-mpe-thermal",
> +		.data = &st_415mpe_data },
> +	{ .compatible = "st,stih416-sas-thermal",
> +		.data = &st_416sas_data },
> +	{ .compatible = "st,stih416-mpe-thermal",
> +		.data = &st_416mpe_data },
> +	{ /* sentinel */ }
> +};
> +
> +static int st_thermal_probe_dt(struct st_thermal_sensor *sensor)
> +{
> +	struct device *dev = sensor_to_dev(sensor);
> +	struct device_node *np = dev->of_node;
> +
> +	sensor->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
> +	if (IS_ERR(sensor->regmap)) {
> +		dev_err(dev, "no syscfg phandle specified\n");
> +		return PTR_ERR(sensor->regmap);
> +	}
> +
> +	sensor->data = of_match_node(st_thermal_of_match, np)->data;
> +	if (!sensor->data->ops)
> +		return -EINVAL;
> +
> +	sensor->ops = sensor->data->ops;
> +	return sensor->ops->alloc_regfields(sensor);
> +}
> +
> +static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
> +{
> +	int ret;
> +	struct device *dev = sensor_to_dev(sensor);
> +
> +	ret = clk_prepare_enable(sensor->clk);
> +	if (ret) {
> +		dev_err(dev, "unable to enable clk\n");
> +		goto out;
> +	}
> +
> +	ret = sensor->ops->power_ctrl(sensor, POWER_ON);
> +	if (ret) {
> +		dev_err(dev, "unable to power on sensor\n");
> +		goto clk_dis;
> +	}
> +	return 0;
> +clk_dis:
> +	clk_disable_unprepare(sensor->clk);
> +out:
> +	return ret;
> +}
> +
> +static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
> +{
> +	int ret;
> +
> +	ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
> +	if (ret)
> +		return ret;
> +
> +	clk_disable_unprepare(sensor->clk);
> +	return 0;
> +}
> +
> +/* Callback to get temperature from HW*/
> +static int st_thermal_get_temp(struct thermal_zone_device *th,
> +		unsigned long *temperature)
> +{
> +	struct st_thermal_sensor *sensor = thzone_to_sensor(th);
> +	struct device *dev = sensor_to_dev(sensor);
> +	unsigned int data;
> +	unsigned int overflow;
> +	int ret;
> +
> +	ret = regmap_field_read(sensor->overflow, &overflow);
> +	if (ret)
> +		return ret;
> +	if (overflow)
> +		return -EIO;
> +
> +	ret = regmap_field_read(sensor->temp_data, &data);
> +	if (ret)
> +		return ret;
> +
> +	data = sensor->ops->adjust_temp(sensor, data);
> +	data = mcelsius(data);
> +	dev_dbg(dev, "%s:temperature:%d\n", __func__, data);
> +
> +	*temperature = data;
> +	return 0;
> +}
> +
> +static int st_thermal_get_trip_type(struct thermal_zone_device *th,
> +				int trip, enum thermal_trip_type *type)
> +{
> +	struct st_thermal_sensor *sensor = thzone_to_sensor(th);
> +	struct device *dev = sensor_to_dev(sensor);
> +
> +	switch (trip) {
> +	case 0:
> +		*type = THERMAL_TRIP_CRITICAL;
> +		break;
> +	default:
> +		dev_err(dev, "invalid trip point\n");
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
> +				    int trip, unsigned long *temp)
> +{
> +	struct st_thermal_sensor *sensor = thzone_to_sensor(th);
> +	struct device *dev = sensor_to_dev(sensor);
> +
> +	switch (trip) {
> +	case 0:
> +		*temp = mcelsius(sensor->data->crit_temp);
> +		break;
> +	default:
> +		dev_err(dev, "Invalid trip point\n");
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static int st_thermal_notify(struct thermal_zone_device *th,
> +			       int trip, enum thermal_trip_type type)
> +{
> +	struct st_thermal_sensor *sensor = thzone_to_sensor(th);
> +	struct device *dev = sensor_to_dev(sensor);
> +
> +	switch (type) {
> +	case THERMAL_TRIP_CRITICAL:
> +		/* TODO: Send event to user space */

It depends on what you mean by that. The core code will attempt to call
the shutdown command, in user space.

> +		dev_err(dev, "Critical temp reached:Going for shutdown\n");
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static struct thermal_zone_device_ops st_tz_ops = {
> +	.get_temp	= st_thermal_get_temp,
> +	.get_trip_type	= st_thermal_get_trip_type,
> +	.get_trip_temp	= st_thermal_get_trip_temp,
> +	.notify		= st_thermal_notify,
> +};
> +
> +static int st_thermal_probe(struct platform_device *pdev)
> +{
> +	struct st_thermal_sensor *sensor;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret;
> +	unsigned int val;
> +	static char start_banner[] __initdata =
> +			"STMicroelectronics thermal sensor initialised\n";
> +
> +	if (!np) {
> +		dev_err(dev, "device node not found\n");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
> +	if (!sensor) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	sensor->pdev = pdev;
> +	ret = st_thermal_probe_dt(sensor);
> +	if (ret)
> +		goto out;
> +
> +	sensor->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(sensor->clk)) {
> +		dev_err(dev, "unable to get clk\n");
> +		ret = PTR_ERR(sensor->clk);
> +		goto out;
> +	}
> +	/* Activate thermal sensor */
> +	ret = st_thermal_sensor_on(sensor);
> +	if (ret) {
> +		dev_err(dev, "unable to power on sensor\n");
> +		goto out;
> +	}
> +
> +	/* Check if sensor calibration data is already written */
> +	ret = regmap_field_read(sensor->dcorrect, &val);
> +	if (ret) {
> +		dev_err(dev, "unable to read calibration data\n");
> +		goto turn_off_exit;
> +	}
> +	if (val == 0) {
> +		/* Sensor calibration value not set by bootloader,
> +		 * default calibration data to be used
> +		 */
> +		ret = regmap_field_write(sensor->dcorrect,
> +				sensor->data->calibration_val);
> +		if (ret) {
> +			dev_err(dev, "unable to set calibration data\n");
> +			goto turn_off_exit;
> +		}
> +	}
> +
> +	sensor->th_dev = thermal_zone_device_register(
> +		(char *)dev_name(dev), 1,
> +		0, (void *)sensor, &st_tz_ops,
> +		NULL, 0, sensor->ops->register_irq ? 0 : 10000);
> +
> +	if (IS_ERR(sensor->th_dev)) {
> +		dev_err(dev, "unable to register thermal zone device\n");
> +		ret = PTR_ERR(sensor->th_dev);
> +		goto turn_off_exit;
> +	}
> +
> +	if (sensor->ops->register_irq) {
> +		ret = sensor->ops->register_irq(sensor);
> +		if (ret) {
> +			dev_err(dev, "unable to register irq\n");
> +			goto unregister_thzone;
> +		}
> +	}
> +
> +	platform_set_drvdata(pdev, sensor);
> +	dev_info(dev, start_banner);
> +	return 0;
> +
> +unregister_thzone:
> +	thermal_zone_device_unregister(sensor->th_dev);
> +turn_off_exit:
> +	st_thermal_sensor_off(sensor);
> +out:
> +	return ret;
> +}
> +
> +static int st_thermal_remove(struct platform_device *pdev)
> +{
> +	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
> +
> +	st_thermal_sensor_off(sensor);
> +	thermal_zone_device_unregister(sensor->th_dev);
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int st_thermal_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
> +
> +	return st_thermal_sensor_off(sensor);
> +}
> +
> +static int st_thermal_resume(struct device *dev)
> +{
> +	int ret;
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
> +
> +	ret = st_thermal_sensor_on(sensor);
> +	if (ret)
> +		return ret;
> +
> +	if (sensor->ops->enable_irq) {
> +		ret = sensor->ops->enable_irq(sensor);
> +		if (ret)
> +			return ret;
> +	}
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend,
> +		st_thermal_resume);
> +
> +MODULE_DEVICE_TABLE(of, st_thermal_of_match);
> +static struct platform_driver st_thermal_driver = {
> +	.driver = {
> +		.name	= DRIVER_NAME,
> +		.owner  = THIS_MODULE,
> +		.of_match_table = st_thermal_of_match,
> +		.pm     = &st_thermal_pm_ops,
> +	},
> +	.probe		= st_thermal_probe,
> +	.remove		= st_thermal_remove,
> +};
> +
> +module_platform_driver(st_thermal_driver);
> +MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
> +MODULE_DESCRIPTION("STMicroelectronics STIH41x SOC thermal sensor driver");
> +MODULE_LICENSE("GPL");

GPL v2?

> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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