[PATCH v2] thermal: st: Add support for STiH41x thermal sensors

[PATCH v2] thermal: st: Add support for STiH41x thermal sensors

[Ajit Pal Singh]

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-qxv4g6HH51o@public.gmane.org>
CC: Srinivas Kandagatla <srinivas.kandagatla-qxv4g6HH51o@public.gmane.org>
Signed-off-by: Ajit Pal Singh <ajitpal.singh-qxv4g6HH51o@public.gmane.org>
---
 .../devicetree/bindings/thermal/st-thermal.txt     |   22 +
 drivers/thermal/Kconfig                            |   11 +
 drivers/thermal/Makefile                           |    1 +
 drivers/thermal/st_thermal.c                       |  632 ++++++++++++++++++++
 4 files changed, 666 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/st-thermal.txt
 create mode 100644 drivers/thermal/st_thermal.c
---
History
v2: Updated with review comments from Eduardo Valentin.

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..dbb573e
--- /dev/null
+++ b/drivers/thermal/st_thermal.c
@@ -0,0 +1,632 @@
+/*
+ * st_thermal.c: ST Thermal Sensor Driver for STIH41x series of SoCs
+ * Author: Ajit Pal Singh <ajitpal.singh-qxv4g6HH51o@public.gmane.org>
+ *
+ * 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);
+	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:
+		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 v2");
-- 
1.7.9.5

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[PATCH v2] thermal: st: Add support for STiH41x thermal sensors

[Ajit Pal Singh]

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@st.com>
CC: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
---
 .../devicetree/bindings/thermal/st-thermal.txt     |   22 +
 drivers/thermal/Kconfig                            |   11 +
 drivers/thermal/Makefile                           |    1 +
 drivers/thermal/st_thermal.c                       |  632 ++++++++++++++++++++
 4 files changed, 666 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/st-thermal.txt
 create mode 100644 drivers/thermal/st_thermal.c
---
History
v2: Updated with review comments from Eduardo Valentin.

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..dbb573e
--- /dev/null
+++ b/drivers/thermal/st_thermal.c
@@ -0,0 +1,632 @@
+/*
+ * st_thermal.c: ST Thermal Sensor Driver for STIH41x series of SoCs
+ * Author: Ajit Pal Singh <ajitpal.singh@st.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);
+	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:
+		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 v2");
-- 
1.7.9.5

Re: [PATCH v2] thermal: st: Add support for STiH41x thermal sensors

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 25616 bytes --]

Hello Ajit,

Sorry for the long delay answering you. I found a couple of minor points
still on this code. Can you please check them?

On 25-09-2013 07:01, 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@st.com>
> CC: Srinivas Kandagatla <srinivas.kandagatla@st.com>
> Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
> ---
>  .../devicetree/bindings/thermal/st-thermal.txt     |   22 +
>  drivers/thermal/Kconfig                            |   11 +
>  drivers/thermal/Makefile                           |    1 +
>  drivers/thermal/st_thermal.c                       |  632 ++++++++++++++++++++
>  4 files changed, 666 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/st-thermal.txt
>  create mode 100644 drivers/thermal/st_thermal.c
> ---
> History
> v2: Updated with review comments from Eduardo Valentin.
> 
> 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.
> +

Might be worth describing the IP and giving a link to hardware
documentation.

> +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

The IP you are adding the support is used only on ARCH_STI and there is
no plan for re-usability?

> +	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..dbb573e
> --- /dev/null
> +++ b/drivers/thermal/st_thermal.c
> @@ -0,0 +1,632 @@
> +/*
> + * st_thermal.c: ST Thermal Sensor Driver for STIH41x series of SoCs
> + * Author: Ajit Pal Singh <ajitpal.singh@st.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;

Are you sure you want this field to be unsigned?

> +};
> +
> +/* 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)

How about following coding style and define the above like (num * 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)

ditto

> +
> +#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);

Do you have plans to increase the complexity of this driver? Assuming
this IRQ handler is fired only on critical temp, you could simply call
ordely_poweroff no?

nip: a matter of taste, but code looks better when  you insert a blank
line before ending returns.

> +	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)

This check is never true as sensor->irq is unsigned. Check my comment on
struct st_thermal_sensor definition.

> +		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);

So we have only the critical temp configured as IRQ event right?


> +}
> +
> +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:
> +		dev_err(dev, "Critical temp reached:Going for shutdown\n");

We have emergency messages on thermal_core.c:

 	if (trip_type == THERMAL_TRIP_CRITICAL) {
 		dev_emerg(&tz->device,
 			  "critical temperature reached(%d C),shutting down\n",
 			  tz->temperature / 1000);
 		orderly_poweroff(true);
 	}

I think they should be enough, no?

> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}

If the purpose of this notification is simply to log the thermal
shutdown, I would recommend to remove this function entirely.

> +
> +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) {

Just for checking here? How about a simple if (!dev->of_node)?

> +		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
> +		 */
/*
 * How about using the coding style of
 * multiline comments?
 */

> +		ret = regmap_field_write(sensor->dcorrect,
> +				sensor->data->calibration_val);

For my own edification, what exactly is this calibration_val? Is it the
same value regardless of your type of sample? It is a constant across
your samples distribution?

> +		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);

10 seconds is enough to see your max temperature rise? Are you confident
that you can catch all temperature rises before it reaches critical
point on all types of samples, independently of your silicon process, no
matter is your temperature starting point?

> +
> +	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);

Why not simply:
+	dev_info(dev, "STMicroelectronics thermal sensor initialised\n");
?

> +	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 v2");
> 


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

Eduardo Valentin


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Re: [PATCH v2] thermal: st: Add support for STiH41x thermal sensors

[Eduardo Valentin]

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Hello Ajit,

Sorry for the long delay answering you. I found a couple of minor points
still on this code. Can you please check them?

On 25-09-2013 07:01, 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@st.com>
> CC: Srinivas Kandagatla <srinivas.kandagatla@st.com>
> Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com>
> ---
>  .../devicetree/bindings/thermal/st-thermal.txt     |   22 +
>  drivers/thermal/Kconfig                            |   11 +
>  drivers/thermal/Makefile                           |    1 +
>  drivers/thermal/st_thermal.c                       |  632 ++++++++++++++++++++
>  4 files changed, 666 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/st-thermal.txt
>  create mode 100644 drivers/thermal/st_thermal.c
> ---
> History
> v2: Updated with review comments from Eduardo Valentin.
> 
> 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.
> +

Might be worth describing the IP and giving a link to hardware
documentation.

> +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

The IP you are adding the support is used only on ARCH_STI and there is
no plan for re-usability?

> +	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..dbb573e
> --- /dev/null
> +++ b/drivers/thermal/st_thermal.c
> @@ -0,0 +1,632 @@
> +/*
> + * st_thermal.c: ST Thermal Sensor Driver for STIH41x series of SoCs
> + * Author: Ajit Pal Singh <ajitpal.singh@st.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;

Are you sure you want this field to be unsigned?

> +};
> +
> +/* 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)

How about following coding style and define the above like (num * 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)

ditto

> +
> +#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);

Do you have plans to increase the complexity of this driver? Assuming
this IRQ handler is fired only on critical temp, you could simply call
ordely_poweroff no?

nip: a matter of taste, but code looks better when  you insert a blank
line before ending returns.

> +	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)

This check is never true as sensor->irq is unsigned. Check my comment on
struct st_thermal_sensor definition.

> +		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);

So we have only the critical temp configured as IRQ event right?


> +}
> +
> +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:
> +		dev_err(dev, "Critical temp reached:Going for shutdown\n");

We have emergency messages on thermal_core.c:

 	if (trip_type == THERMAL_TRIP_CRITICAL) {
 		dev_emerg(&tz->device,
 			  "critical temperature reached(%d C),shutting down\n",
 			  tz->temperature / 1000);
 		orderly_poweroff(true);
 	}

I think they should be enough, no?

> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}

If the purpose of this notification is simply to log the thermal
shutdown, I would recommend to remove this function entirely.

> +
> +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) {

Just for checking here? How about a simple if (!dev->of_node)?

> +		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
> +		 */
/*
 * How about using the coding style of
 * multiline comments?
 */

> +		ret = regmap_field_write(sensor->dcorrect,
> +				sensor->data->calibration_val);

For my own edification, what exactly is this calibration_val? Is it the
same value regardless of your type of sample? It is a constant across
your samples distribution?

> +		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);

10 seconds is enough to see your max temperature rise? Are you confident
that you can catch all temperature rises before it reaches critical
point on all types of samples, independently of your silicon process, no
matter is your temperature starting point?

> +
> +	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);

Why not simply:
+	dev_info(dev, "STMicroelectronics thermal sensor initialised\n");
?

> +	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 v2");
> 


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

Eduardo Valentin


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