3 files changed, 775 insertions, 0 deletions

diff --git a/drivers/thermal/st/Kconfig b/drivers/thermal/st/Kconfig
index 490fdbe22eea..b80f9a9e4f8f 100644
--- a/drivers/thermal/st/Kconfig
+++ b/drivers/thermal/st/Kconfig
@@ -1,3 +1,7 @@
+#
+# STMicroelectronics thermal drivers configuration
+#
+
 config ST_THERMAL
        tristate "Thermal sensors on STMicroelectronics STi series of SoCs"
        help
@@ -10,3 +14,13 @@ config ST_THERMAL_SYSCFG
 config ST_THERMAL_MEMMAP
 	select ST_THERMAL
 	tristate "STi series memory mapped access based thermal sensors"
+
+config STM32_THERMAL
+       tristate "Thermal framework support on STMicroelectronics STM32 series of SoCs"
+       depends on MACH_STM32MP157
+       default y
+       help
+	Support for thermal framework on STMicroelectronics STM32 series of
+	SoCs. This thermal driver allows to access to general thermal framework
+	functionalities and to acces to SoC sensor functionalities. This
+	configuration is fully dependent of MACH_STM32MP157.
diff --git a/drivers/thermal/st/Makefile b/drivers/thermal/st/Makefile
index b38878977bd8..b2b9e9b96296 100644
--- a/drivers/thermal/st/Makefile
+++ b/drivers/thermal/st/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_ST_THERMAL)		:= st_thermal.o
 obj-$(CONFIG_ST_THERMAL_SYSCFG)		+= st_thermal_syscfg.o
 obj-$(CONFIG_ST_THERMAL_MEMMAP)		+= st_thermal_memmap.o
+obj-$(CONFIG_STM32_THERMAL)		:= stm_thermal.o
\ No newline at end of file
diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c
new file mode 100644
index 000000000000..47623da0f91b
--- /dev/null
+++ b/drivers/thermal/st/stm_thermal.c
@@ -0,0 +1,760 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
+ * Author: David Hernandez Sanchez <david.hernandezsanchez@st.com> for
+ * STMicroelectronics.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#include "../thermal_core.h"
+#include "../thermal_hwmon.h"
+
+/* DTS register offsets */
+#define DTS_CFGR1_OFFSET	0x0
+#define DTS_T0VALR1_OFFSET	0x8
+#define DTS_RAMPVALR_OFFSET	0X10
+#define DTS_ITR1_OFFSET		0x14
+#define DTS_DR_OFFSET		0x1C
+#define DTS_SR_OFFSET		0x20
+#define DTS_ITENR_OFFSET	0x24
+#define DTS_CIFR_OFFSET		0x28
+
+/* DTS_CFGR1 register mask definitions */
+#define HSREF_CLK_DIV_MASK	GENMASK(30, 24)
+#define TS1_SMP_TIME_MASK	GENMASK(19, 16)
+#define TS1_INTRIG_SEL_MASK	GENMASK(11, 8)
+
+/* DTS_T0VALR1 register mask definitions */
+#define TS1_T0_MASK		GENMASK(17, 16)
+#define TS1_FMT0_MASK		GENMASK(15, 0)
+
+/* DTS_RAMPVALR register mask definitions */
+#define TS1_RAMP_COEFF_MASK	GENMASK(15, 0)
+
+/* DTS_ITR1 register mask definitions */
+#define TS1_HITTHD_MASK		GENMASK(31, 16)
+#define TS1_LITTHD_MASK		GENMASK(15, 0)
+
+/* DTS_DR register mask definitions */
+#define TS1_MFREQ_MASK		GENMASK(15, 0)
+
+/* Less significant bit position definitions */
+#define TS1_T0_POS		16
+#define TS1_SMP_TIME_POS	16
+#define TS1_HITTHD_POS		16
+#define HSREF_CLK_DIV_POS	24
+
+/* DTS_CFGR1 bit definitions */
+#define TS1_EN			BIT(0)
+#define TS1_START		BIT(4)
+#define REFCLK_SEL		BIT(20)
+#define REFCLK_LSE		REFCLK_SEL
+#define Q_MEAS_OPT		BIT(21)
+#define CALIBRATION_CONTROL	Q_MEAS_OPT
+
+/* DTS_SR bit definitions */
+#define TS_RDY			BIT(15)
+/* Bit definitions below are common for DTS_SR, DTS_ITENR and DTS_CIFR */
+#define HIGH_THRESHOLD		BIT(2)
+#define LOW_THRESHOLD		BIT(1)
+
+/* Constants */
+#define ADJUST			100
+#define ONE_MHZ			1000000
+#define POLL_TIMEOUT		5000
+#define STARTUP_TIME		40
+#define TS1_T0_VAL0		30
+#define TS1_T0_VAL1		130
+#define NO_HW_TRIG		0
+
+/* The Thermal Framework expects millidegrees */
+#define mcelsius(temp)		((temp) * 1000)
+
+/* The Sensor expects oC degrees */
+#define celsius(temp)		((temp) / 1000)
+
+struct stm_thermal_sensor {
+	struct device *dev;
+	struct thermal_zone_device *th_dev;
+	enum thermal_device_mode mode;
+	struct clk *clk;
+	int high_temp;
+	int low_temp;
+	int temp_critical;
+	int temp_passive;
+	unsigned int low_temp_enabled;
+	int num_trips;
+	int irq;
+	unsigned int irq_enabled;
+	void __iomem *base;
+	int t0, fmt0, ramp_coeff;
+};
+
+static irqreturn_t stm_thermal_alarm_irq(int irq, void *sdata)
+{
+	struct stm_thermal_sensor *sensor = sdata;
+
+	disable_irq_nosync(irq);
+	sensor->irq_enabled = false;
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t stm_thermal_alarm_irq_thread(int irq, void *sdata)
+{
+	u32 value;
+	struct stm_thermal_sensor *sensor = sdata;
+
+	/* read IT reason in SR and clear flags */
+	value = readl_relaxed(sensor->base + DTS_SR_OFFSET);
+
+	if ((value & LOW_THRESHOLD) == LOW_THRESHOLD)
+		writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+
+	if ((value & HIGH_THRESHOLD) == HIGH_THRESHOLD)
+		writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+
+	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
+
+	return IRQ_HANDLED;
+}
+
+static int stm_sensor_power_on(struct stm_thermal_sensor *sensor)
+{
+	int ret;
+	u32 value;
+
+	/* Enable sensor */
+	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
+	value |= TS1_EN;
+	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
+
+	/*
+	 * The DTS block can be enabled by setting TSx_EN bit in
+	 * DTS_CFGRx register. It requires a startup time of
+	 * 40μs. Use 5 ms as arbitrary timeout.
+	 */
+	ret = readl_poll_timeout(sensor->base + DTS_SR_OFFSET,
+				 value, (value & TS_RDY),
+				 STARTUP_TIME, POLL_TIMEOUT);
+	if (ret)
+		return ret;
+
+	/* Start continuous measuring */
+	value = readl_relaxed(sensor->base +
+			      DTS_CFGR1_OFFSET);
+	value |= TS1_START;
+	writel_relaxed(value, sensor->base +
+		       DTS_CFGR1_OFFSET);
+
+	return 0;
+}
+
+static int stm_sensor_power_off(struct stm_thermal_sensor *sensor)
+{
+	u32 value;
+
+	/* Stop measuring */
+	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
+	value &= ~TS1_START;
+	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
+
+	/* Ensure stop is taken into account */
+	usleep_range(STARTUP_TIME, POLL_TIMEOUT);
+
+	/* Disable sensor */
+	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
+	value &= ~TS1_EN;
+	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
+
+	/* Ensure disable is taken into account */
+	return readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value,
+				  !(value & TS_RDY),
+				  STARTUP_TIME, POLL_TIMEOUT);
+}
+
+static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
+{
+	u32 value, clk_freq;
+	u32 prescaler;
+
+	/* Figure out prescaler value for PCLK during calibration */
+	clk_freq = clk_get_rate(sensor->clk);
+	if (!clk_freq)
+		return -EINVAL;
+
+	prescaler = 0;
+	clk_freq /= ONE_MHZ;
+	if (clk_freq) {
+		while (prescaler <= clk_freq)
+			prescaler++;
+	}
+
+	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
+
+	/* Clear prescaler */
+	value &= ~HSREF_CLK_DIV_MASK;
+
+	/* Set prescaler. pclk_freq/prescaler < 1MHz */
+	value |= (prescaler << HSREF_CLK_DIV_POS);
+
+	/* Select PCLK as reference clock */
+	value &= ~REFCLK_SEL;
+
+	/* Set maximal sampling time for better precision */
+	value |= TS1_SMP_TIME_MASK;
+
+	/* Measure with calibration */
+	value &= ~CALIBRATION_CONTROL;
+
+	/* select trigger */
+	value &= ~TS1_INTRIG_SEL_MASK;
+	value |= NO_HW_TRIG;
+
+	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
+
+	return 0;
+}
+
+/* Fill in DTS structure with factory sensor values */
+static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor)
+{
+	/* Retrieve engineering calibration temperature */
+	sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) &
+					TS1_T0_MASK;
+	if (!sensor->t0)
+		sensor->t0 = TS1_T0_VAL0;
+	else
+		sensor->t0 = TS1_T0_VAL1;
+
+	/* Retrieve fmt0 and put it on Hz */
+	sensor->fmt0 = ADJUST * readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET)
+					      & TS1_FMT0_MASK;
+
+	/* Retrieve ramp coefficient */
+	sensor->ramp_coeff = readl_relaxed(sensor->base + DTS_RAMPVALR_OFFSET) &
+					   TS1_RAMP_COEFF_MASK;
+
+	if (!sensor->fmt0 || !sensor->ramp_coeff) {
+		dev_err(sensor->dev, "%s: wrong setting\n", __func__);
+		return -EINVAL;
+	}
+
+	dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC",
+		__func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff);
+
+	return 0;
+}
+
+static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
+					   int temp, u32 *th)
+{
+	int freqM;
+	u32 sampling_time;
+
+	/* Retrieve the number of periods to sample */
+	sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
+			TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
+
+	/* Figure out the CLK_PTAT frequency for a given temperature */
+	freqM = ((temp - sensor->t0) * sensor->ramp_coeff)
+		 + sensor->fmt0;
+
+	dev_dbg(sensor->dev, "%s: freqM for threshold = %d Hz",
+		__func__, freqM);
+
+	/* Figure out the threshold sample number */
+	*th = clk_get_rate(sensor->clk);
+	if (!*th)
+		return -EINVAL;
+
+	*th = *th / freqM;
+
+	*th *= sampling_time;
+
+	return 0;
+}
+
+static int stm_thermal_set_threshold(struct stm_thermal_sensor *sensor)
+{
+	u32 value, th;
+	int ret;
+
+	value = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
+
+	/* Erase threshold content */
+	value &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK);
+
+	/* Retrieve the sample threshold number th for a given temperature */
+	ret = stm_thermal_calculate_threshold(sensor, sensor->high_temp, &th);
+	if (ret)
+		return ret;
+
+	value |= th & TS1_LITTHD_MASK;
+
+	if (sensor->low_temp_enabled) {
+		/* Retrieve the sample threshold */
+		ret = stm_thermal_calculate_threshold(sensor, sensor->low_temp,
+						      &th);
+		if (ret)
+			return ret;
+
+		value |= (TS1_HITTHD_MASK  & (th << TS1_HITTHD_POS));
+	}
+
+	/* Write value on the Low interrupt threshold */
+	writel_relaxed(value, sensor->base + DTS_ITR1_OFFSET);
+
+	return 0;
+}
+
+/* Disable temperature interrupt */
+static int stm_disable_irq(struct stm_thermal_sensor *sensor)
+{
+	u32 value;
+
+	/* Disable IT generation for low and high thresholds */
+	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
+	writel_relaxed(value & ~(LOW_THRESHOLD | HIGH_THRESHOLD),
+		       sensor->base + DTS_ITENR_OFFSET);
+
+	dev_dbg(sensor->dev, "%s: IT disabled on sensor side", __func__);
+
+	return 0;
+}
+
+/* Enable temperature interrupt */
+static int stm_enable_irq(struct stm_thermal_sensor *sensor)
+{
+	u32 value;
+
+	/*
+	 * Code below enables High temperature threshold using a low threshold
+	 * sampling value
+	 */
+
+	/* Make sure LOW_THRESHOLD IT is clear before enabling */
+	writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+
+	/* Enable IT generation for low threshold */
+	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
+	value |= LOW_THRESHOLD;
+
+	/* Enable the low temperature threshold if needed */
+	if (sensor->low_temp_enabled) {
+		/* Make sure HIGH_THRESHOLD IT is clear before enabling */
+		writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+
+		/* Enable IT generation for high threshold */
+		value |= HIGH_THRESHOLD;
+	}
+
+	/* Enable thresholds */
+	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);
+
+	dev_dbg(sensor->dev, "%s: IT enabled on sensor side", __func__);
+
+	return 0;
+}
+
+static int stm_thermal_update_threshold(struct stm_thermal_sensor *sensor)
+{
+	int ret;
+
+	sensor->mode = THERMAL_DEVICE_DISABLED;
+
+	ret = stm_sensor_power_off(sensor);
+	if (ret)
+		return ret;
+
+	ret = stm_disable_irq(sensor);
+	if (ret)
+		return ret;
+
+	ret = stm_thermal_set_threshold(sensor);
+	if (ret)
+		return ret;
+
+	ret = stm_enable_irq(sensor);
+	if (ret)
+		return ret;
+
+	ret = stm_sensor_power_on(sensor);
+	if (ret)
+		return ret;
+
+	sensor->mode = THERMAL_DEVICE_ENABLED;
+
+	return 0;
+}
+
+/* Callback to get temperature from HW */
+static int stm_thermal_get_temp(void *data, int *temp)
+{
+	struct stm_thermal_sensor *sensor = data;
+	u32 sampling_time;
+	int freqM, ret;
+
+	if (sensor->mode != THERMAL_DEVICE_ENABLED)
+		return -EAGAIN;
+
+	/* Retrieve the number of samples */
+	ret = readl_poll_timeout(sensor->base + DTS_DR_OFFSET, freqM,
+				 (freqM & TS1_MFREQ_MASK), STARTUP_TIME,
+				 POLL_TIMEOUT);
+
+	if (ret)
+		return ret;
+
+	if (!freqM)
+		return -ENODATA;
+
+	/* Retrieve the number of periods sampled */
+	sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
+			TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
+
+	/* Figure out the number of samples per period */
+	freqM /= sampling_time;
+
+	/* Figure out the CLK_PTAT frequency */
+	freqM = clk_get_rate(sensor->clk) / freqM;
+	if (!freqM)
+		return -EINVAL;
+
+	dev_dbg(sensor->dev, "%s: freqM=%d\n", __func__, freqM);
+
+	/* Figure out the temperature in mili celsius */
+	*temp = mcelsius(sensor->t0 + ((freqM - sensor->fmt0) /
+			 sensor->ramp_coeff));
+
+	dev_dbg(sensor->dev, "%s: temperature = %d millicelsius",
+		__func__, *temp);
+
+	/* Update thresholds */
+	if (sensor->num_trips > 1) {
+		/* Update alarm threshold value to next higher trip point */
+		if (sensor->high_temp == sensor->temp_passive &&
+		    celsius(*temp) >= sensor->temp_passive) {
+			sensor->high_temp = sensor->temp_critical;
+			sensor->low_temp = sensor->temp_passive;
+			sensor->low_temp_enabled = true;
+			ret = stm_thermal_update_threshold(sensor);
+			if (ret)
+				return ret;
+		}
+
+		if (sensor->high_temp == sensor->temp_critical &&
+		    celsius(*temp) < sensor->temp_passive) {
+			sensor->high_temp = sensor->temp_passive;
+			sensor->low_temp_enabled = false;
+			ret = stm_thermal_update_threshold(sensor);
+			if (ret)
+				return ret;
+		}
+
+		/*
+		 * Re-enable alarm IRQ if temperature below critical
+		 * temperature
+		 */
+		if (!sensor->irq_enabled &&
+		    (celsius(*temp) < sensor->temp_critical)) {
+			sensor->irq_enabled = true;
+			enable_irq(sensor->irq);
+		}
+	}
+
+	return 0;
+}
+
+/* Registers DTS irq to be visible by GIC */
+static int stm_register_irq(struct stm_thermal_sensor *sensor)
+{
+	struct device *dev = sensor->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	int ret;
+
+	sensor->irq = platform_get_irq(pdev, 0);
+	if (sensor->irq < 0) {
+		dev_err(dev, "%s: Unable to find IRQ\n", __func__);
+		return sensor->irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, sensor->irq,
+					stm_thermal_alarm_irq,
+					stm_thermal_alarm_irq_thread,
+					IRQF_ONESHOT,
+					dev->driver->name, sensor);
+	if (ret) {
+		dev_err(dev, "%s: Failed to register IRQ %d\n", __func__,
+			sensor->irq);
+		return ret;
+	}
+
+	sensor->irq_enabled = true;
+
+	dev_dbg(dev, "%s: thermal IRQ registered", __func__);
+
+	return 0;
+}
+
+static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
+{
+	int ret;
+
+	ret = stm_sensor_power_off(sensor);
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(sensor->clk);
+
+	return 0;
+}
+
+static int stm_thermal_prepare(struct stm_thermal_sensor *sensor)
+{
+	int ret;
+	struct device *dev = sensor->dev;
+
+	ret = clk_prepare_enable(sensor->clk);
+	if (ret)
+		return ret;
+
+	ret = stm_thermal_calibration(sensor);
+	if (ret)
+		goto thermal_unprepare;
+
+	/* Set threshold(s) for IRQ */
+	ret = stm_thermal_set_threshold(sensor);
+	if (ret)
+		goto thermal_unprepare;
+
+	ret = stm_enable_irq(sensor);
+	if (ret)
+		goto thermal_unprepare;
+
+	ret = stm_sensor_power_on(sensor);
+	if (ret) {
+		dev_err(dev, "%s: failed to power on sensor\n", __func__);
+		goto irq_disable;
+	}
+
+	return 0;
+
+irq_disable:
+	stm_disable_irq(sensor);
+
+thermal_unprepare:
+	clk_disable_unprepare(sensor->clk);
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stm_thermal_suspend(struct device *dev)
+{
+	int ret;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
+
+	ret = stm_thermal_sensor_off(sensor);
+	if (ret)
+		return ret;
+
+	sensor->mode = THERMAL_DEVICE_DISABLED;
+
+	return 0;
+}
+
+static int stm_thermal_resume(struct device *dev)
+{
+	int ret;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
+
+	ret = stm_thermal_prepare(sensor);
+	if (ret)
+		return ret;
+
+	sensor->mode = THERMAL_DEVICE_ENABLED;
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, stm_thermal_suspend, stm_thermal_resume);
+
+static const struct thermal_zone_of_device_ops stm_tz_ops = {
+	.get_temp	= stm_thermal_get_temp,
+};
+
+static const struct of_device_id stm_thermal_of_match[] = {
+		{ .compatible = "st,stm32-thermal"},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, stm_thermal_of_match);
+
+static int stm_thermal_probe(struct platform_device *pdev)
+{
+	struct stm_thermal_sensor *sensor;
+	struct resource *res;
+	const struct thermal_trip *trip;
+	void __iomem *base;
+	int ret, i;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "%s: device tree node not found\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);
+	if (!sensor)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, sensor);
+
+	sensor->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	/* Populate sensor */
+	sensor->base = base;
+
+	ret = stm_thermal_read_factory_settings(sensor);
+	if (ret)
+		return ret;
+
+	sensor->clk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(sensor->clk)) {
+		dev_err(&pdev->dev, "%s: failed to fetch PCLK clock\n",
+			__func__);
+		return PTR_ERR(sensor->clk);
+	}
+
+	/* Register IRQ into GIC */
+	ret = stm_register_irq(sensor);
+	if (ret)
+		return ret;
+
+	sensor->th_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
+							      sensor,
+							      &stm_tz_ops);
+
+	if (IS_ERR(sensor->th_dev)) {
+		dev_err(&pdev->dev, "%s: thermal zone sensor registering KO\n",
+			__func__);
+		ret = PTR_ERR(sensor->th_dev);
+		return ret;
+	}
+
+	if (!sensor->th_dev->ops->get_crit_temp) {
+		/* Critical point must be provided */
+		ret = -EINVAL;
+		goto err_tz;
+	}
+
+	ret = sensor->th_dev->ops->get_crit_temp(sensor->th_dev,
+			&sensor->temp_critical);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Not able to read critical_temp: %d\n", ret);
+		goto err_tz;
+	}
+
+	sensor->temp_critical = celsius(sensor->temp_critical);
+
+	/* Set thresholds for IRQ */
+	sensor->high_temp = sensor->temp_critical;
+
+	trip = of_thermal_get_trip_points(sensor->th_dev);
+	sensor->num_trips = of_thermal_get_ntrips(sensor->th_dev);
+
+	/* Find out passive temperature if it exists */
+	for (i = (sensor->num_trips - 1); i >= 0;  i--) {
+		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
+			sensor->temp_passive = celsius(trip[i].temperature);
+			/* Update high temperature threshold */
+			sensor->high_temp = sensor->temp_passive;
+			}
+	}
+
+	/*
+	 * Ensure low_temp_enabled flag is disabled.
+	 * By disabling low_temp_enabled, low threshold IT will not be
+	 * configured neither enabled because it is not needed as high
+	 * threshold is set on the lowest temperature trip point after
+	 * probe.
+	 */
+	sensor->low_temp_enabled = false;
+
+	/* Configure and enable HW sensor */
+	ret = stm_thermal_prepare(sensor);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Not able to enable sensor: %d\n", ret);
+		goto err_tz;
+	}
+
+	/*
+	 * Thermal_zone doesn't enable hwmon as default,
+	 * enable it here
+	 */
+	sensor->th_dev->tzp->no_hwmon = false;
+	ret = thermal_add_hwmon_sysfs(sensor->th_dev);
+	if (ret)
+		goto err_tz;
+
+	sensor->mode = THERMAL_DEVICE_ENABLED;
+
+	dev_info(&pdev->dev, "%s: Driver initialized successfully\n",
+		 __func__);
+
+	return 0;
+
+err_tz:
+	thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
+	return ret;
+}
+
+static int stm_thermal_remove(struct platform_device *pdev)
+{
+	struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
+
+	stm_thermal_sensor_off(sensor);
+	thermal_remove_hwmon_sysfs(sensor->th_dev);
+	thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
+
+	return 0;
+}
+
+static struct platform_driver stm_thermal_driver = {
+	.driver = {
+		.name	= "stm_thermal",
+		.pm     = &stm_thermal_pm_ops,
+		.of_match_table = stm_thermal_of_match,
+	},
+	.probe		= stm_thermal_probe,
+	.remove		= stm_thermal_remove,
+};
+module_platform_driver(stm_thermal_driver);
+
+MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver");
+MODULE_AUTHOR("David Hernandez Sanchez <david.hernandezsanchez@st.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stm_thermal");