[linux-block.git] / drivers / thermal / st / stm_thermal.c

// 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_ICIFR_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)

/* DTS_ITENR register mask definitions */
#define ITENR_MASK		(GENMASK(2, 0) | GENMASK(6, 4))

/* DTS_ICIFR register mask definitions */
#define ICIFR_MASK		(GENMASK(2, 0) | GENMASK(6, 4))

/* Less significant bit position definitions */
#define TS1_T0_POS		16
#define TS1_HITTHD_POS		16
#define TS1_LITTHD_POS		0
#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		30000  /* 30 celsius */
#define TS1_T0_VAL1		130000 /* 130 celsius */
#define NO_HW_TRIG		0
#define SAMPLING_TIME		15

struct stm_thermal_sensor {
	struct device *dev;
	struct thermal_zone_device *th_dev;
	enum thermal_device_mode mode;
	struct clk *clk;
	unsigned int low_temp_enabled;
	unsigned int high_temp_enabled;
	int irq;
	void __iomem *base;
	int t0, fmt0, ramp_coeff;
};

static int stm_enable_irq(struct stm_thermal_sensor *sensor)
{
	u32 value;

	dev_dbg(sensor->dev, "low:%d high:%d\n", sensor->low_temp_enabled,
		sensor->high_temp_enabled);

	/* Disable IT generation for low and high thresholds */
	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
	value &= ~(LOW_THRESHOLD | HIGH_THRESHOLD);

	if (sensor->low_temp_enabled)
		value |= HIGH_THRESHOLD;

	if (sensor->high_temp_enabled)
		value |= LOW_THRESHOLD;

	/* Enable interrupts */
	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);

	return 0;
}

static irqreturn_t stm_thermal_irq_handler(int irq, void *sdata)
{
	struct stm_thermal_sensor *sensor = sdata;

	dev_dbg(sensor->dev, "sr:%d\n",
		readl_relaxed(sensor->base + DTS_SR_OFFSET));

	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);

	stm_enable_irq(sensor);

	/* Acknoledge all DTS irqs */
	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);

	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);

	sensor->mode = THERMAL_DEVICE_ENABLED;

	return 0;
}

static int stm_sensor_power_off(struct stm_thermal_sensor *sensor)
{
	u32 value;

	sensor->mode = THERMAL_DEVICE_DISABLED;

	/* 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;

	/* Figure out the CLK_PTAT frequency for a given temperature */
	freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 +
		sensor->fmt0;

	/* Figure out the threshold sample number */
	*th = clk_get_rate(sensor->clk) * SAMPLING_TIME / freqM;
	if (!*th)
		return -EINVAL;

	dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th);

	return 0;
}

/* Disable temperature interrupt */
static int stm_disable_irq(struct stm_thermal_sensor *sensor)
{
	u32 value;

	/* Disable IT generation */
	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
	value &= ~ITENR_MASK;
	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);

	return 0;
}

static int stm_thermal_set_trips(void *data, int low, int high)
{
	struct stm_thermal_sensor *sensor = data;
	u32 itr1, th;
	int ret;

	dev_dbg(sensor->dev, "set trips %d <--> %d\n", low, high);

	/* Erase threshold content */
	itr1 = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
	itr1 &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK);

	/*
	 * Disable low-temp if "low" is too small. As per thermal framework
	 * API, we use -INT_MAX rather than INT_MIN.
	 */

	if (low > -INT_MAX) {
		sensor->low_temp_enabled = 1;
		/* add 0.5 of hysteresis due to measurement error */
		ret = stm_thermal_calculate_threshold(sensor, low - 500, &th);
		if (ret)
			return ret;

		itr1 |= (TS1_HITTHD_MASK  & (th << TS1_HITTHD_POS));
	} else {
		sensor->low_temp_enabled = 0;
	}

	/* Disable high-temp if "high" is too big. */
	if (high < INT_MAX) {
		sensor->high_temp_enabled = 1;
		ret = stm_thermal_calculate_threshold(sensor, high, &th);
		if (ret)
			return ret;

		itr1 |= (TS1_LITTHD_MASK  & (th << TS1_LITTHD_POS));
	} else {
		sensor->high_temp_enabled = 0;
	}

	/* Write new threshod values*/
	writel_relaxed(itr1, sensor->base + DTS_ITR1_OFFSET);

	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 periods;
	int freqM, ret;

	if (sensor->mode != THERMAL_DEVICE_ENABLED)
		return -EAGAIN;

	/* Retrieve the number of periods sampled */
	ret = readl_relaxed_poll_timeout(sensor->base + DTS_DR_OFFSET, periods,
					 (periods & TS1_MFREQ_MASK),
					 STARTUP_TIME, POLL_TIMEOUT);
	if (ret)
		return ret;

	/* Figure out the CLK_PTAT frequency */
	freqM = (clk_get_rate(sensor->clk) * SAMPLING_TIME) / periods;
	if (!freqM)
		return -EINVAL;

	/* Figure out the temperature in mili celsius */
	*temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + sensor->t0;

	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)
		return sensor->irq;

	ret = devm_request_threaded_irq(dev, sensor->irq,
					NULL,
					stm_thermal_irq_handler,
					IRQF_ONESHOT,
					dev->driver->name, sensor);
	if (ret) {
		dev_err(dev, "%s: Failed to register IRQ %d\n", __func__,
			sensor->irq);
		return ret;
	}

	dev_dbg(dev, "%s: thermal IRQ registered", __func__);

	return 0;
}

static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
{
	int ret;

	stm_disable_irq(sensor);

	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;

	ret = clk_prepare_enable(sensor->clk);
	if (ret)
		return ret;

	ret = stm_thermal_read_factory_settings(sensor);
	if (ret)
		goto thermal_unprepare;

	ret = stm_thermal_calibration(sensor);
	if (ret)
		goto thermal_unprepare;

	return 0;

thermal_unprepare:
	clk_disable_unprepare(sensor->clk);

	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int stm_thermal_suspend(struct device *dev)
{
	struct stm_thermal_sensor *sensor = dev_get_drvdata(dev);

	return stm_thermal_sensor_off(sensor);
}

static int stm_thermal_resume(struct device *dev)
{
	int ret;
	struct stm_thermal_sensor *sensor = dev_get_drvdata(dev);

	ret = stm_thermal_prepare(sensor);
	if (ret)
		return ret;

	ret = stm_sensor_power_on(sensor);
	if (ret)
		return ret;

	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
	stm_enable_irq(sensor);

	return 0;
}
#endif /* CONFIG_PM_SLEEP */

static 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,
	.set_trips	= stm_thermal_set_trips,
};

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;
	void __iomem *base;
	int ret;

	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;

	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);
	}

	stm_disable_irq(sensor);

	/* Clear irq flags */
	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);

	/* Configure and enable HW sensor */
	ret = stm_thermal_prepare(sensor);
	if (ret) {
		dev_err(&pdev->dev, "Error prepare sensor: %d\n", ret);
		return ret;
	}

	ret = stm_sensor_power_on(sensor);
	if (ret) {
		dev_err(&pdev->dev, "Error power on sensor: %d\n", 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;
	}

	/* Register IRQ into GIC */
	ret = stm_register_irq(sensor);
	if (ret)
		goto err_tz;

	stm_enable_irq(sensor);

	/*
	 * 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;

	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");
Commit	Line	Data
1d693155 DHS	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
	4	* Author: David Hernandez Sanchez <david.hernandezsanchez@st.com> for
	5	* STMicroelectronics.
	6	*/
	7
	8	#include <linux/clk.h>
	9	#include <linux/clk-provider.h>
	10	#include <linux/delay.h>
	11	#include <linux/err.h>
	12	#include <linux/interrupt.h>
	13	#include <linux/io.h>
	14	#include <linux/iopoll.h>
	15	#include <linux/module.h>
	16	#include <linux/of.h>
	17	#include <linux/of_address.h>
	18	#include <linux/of_device.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/thermal.h>
	21
	22	#include "../thermal_core.h"
	23	#include "../thermal_hwmon.h"
	24
	25	/* DTS register offsets */
	26	#define DTS_CFGR1_OFFSET 0x0
	27	#define DTS_T0VALR1_OFFSET 0x8
	28	#define DTS_RAMPVALR_OFFSET 0X10
	29	#define DTS_ITR1_OFFSET 0x14
	30	#define DTS_DR_OFFSET 0x1C
	31	#define DTS_SR_OFFSET 0x20
	32	#define DTS_ITENR_OFFSET 0x24
d401652c	33	#define DTS_ICIFR_OFFSET 0x28
1d693155 DHS	34
	35	/* DTS_CFGR1 register mask definitions */
	36	#define HSREF_CLK_DIV_MASK GENMASK(30, 24)
	37	#define TS1_SMP_TIME_MASK GENMASK(19, 16)
	38	#define TS1_INTRIG_SEL_MASK GENMASK(11, 8)
	39
	40	/* DTS_T0VALR1 register mask definitions */
	41	#define TS1_T0_MASK GENMASK(17, 16)
	42	#define TS1_FMT0_MASK GENMASK(15, 0)
	43
	44	/* DTS_RAMPVALR register mask definitions */
	45	#define TS1_RAMP_COEFF_MASK GENMASK(15, 0)
	46
	47	/* DTS_ITR1 register mask definitions */
	48	#define TS1_HITTHD_MASK GENMASK(31, 16)
	49	#define TS1_LITTHD_MASK GENMASK(15, 0)
	50
	51	/* DTS_DR register mask definitions */
	52	#define TS1_MFREQ_MASK GENMASK(15, 0)
	53
1f64fa36 PP	54	/* DTS_ITENR register mask definitions */
	55	#define ITENR_MASK (GENMASK(2, 0) \| GENMASK(6, 4))
	56
	57	/* DTS_ICIFR register mask definitions */
	58	#define ICIFR_MASK (GENMASK(2, 0) \| GENMASK(6, 4))
	59
1d693155 DHS	60	/* Less significant bit position definitions */
1d693155 DHS	61	#define TS1_T0_POS 16
1d693155	62	#define TS1_HITTHD_POS 16
dd4c3919	63	#define TS1_LITTHD_POS 0
1d693155 DHS	64	#define HSREF_CLK_DIV_POS 24
	65
	66	/* DTS_CFGR1 bit definitions */
	67	#define TS1_EN BIT(0)
	68	#define TS1_START BIT(4)
	69	#define REFCLK_SEL BIT(20)
	70	#define REFCLK_LSE REFCLK_SEL
	71	#define Q_MEAS_OPT BIT(21)
	72	#define CALIBRATION_CONTROL Q_MEAS_OPT
	73
	74	/* DTS_SR bit definitions */
	75	#define TS_RDY BIT(15)
	76	/* Bit definitions below are common for DTS_SR, DTS_ITENR and DTS_CIFR */
	77	#define HIGH_THRESHOLD BIT(2)
	78	#define LOW_THRESHOLD BIT(1)
	79
	80	/* Constants */
	81	#define ADJUST 100
	82	#define ONE_MHZ 1000000
	83	#define POLL_TIMEOUT 5000
	84	#define STARTUP_TIME 40
9d8593f2 PP	85	#define TS1_T0_VAL0 30000 /* 30 celsius */
9d8593f2 PP	86	#define TS1_T0_VAL1 130000 /* 130 celsius */
1d693155	87	#define NO_HW_TRIG 0
9d8593f2	88	#define SAMPLING_TIME 15
1d693155 DHS	89
	90	struct stm_thermal_sensor {
	91	struct device *dev;
	92	struct thermal_zone_device *th_dev;
	93	enum thermal_device_mode mode;
	94	struct clk *clk;
1d693155	95	unsigned int low_temp_enabled;
dd4c3919	96	unsigned int high_temp_enabled;
1d693155	97	int irq;
1d693155 DHS	98	void __iomem *base;
	99	int t0, fmt0, ramp_coeff;
	100	};
	101
dd4c3919	102	static int stm_enable_irq(struct stm_thermal_sensor *sensor)
1d693155	103	{
dd4c3919	104	u32 value;
1d693155	105
dd4c3919 PP	106	dev_dbg(sensor->dev, "low:%d high:%d\n", sensor->low_temp_enabled,
	107	sensor->high_temp_enabled);
	108
	109	/* Disable IT generation for low and high thresholds */
	110	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
	111	value &= ~(LOW_THRESHOLD \| HIGH_THRESHOLD);
1d693155	112
dd4c3919 PP	113	if (sensor->low_temp_enabled)
	114	value \|= HIGH_THRESHOLD;
	115
	116	if (sensor->high_temp_enabled)
	117	value \|= LOW_THRESHOLD;
	118
	119	/* Enable interrupts */
	120	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);
	121
	122	return 0;
1d693155 DHS	123	}
1d693155 DHS	124
dd4c3919	125	static irqreturn_t stm_thermal_irq_handler(int irq, void *sdata)
1d693155	126	{
1d693155 DHS	127	struct stm_thermal_sensor *sensor = sdata;
1d693155 DHS	128
dd4c3919 PP	129	dev_dbg(sensor->dev, "sr:%d\n",
dd4c3919 PP	130	readl_relaxed(sensor->base + DTS_SR_OFFSET));
1d693155	131
dd4c3919	132	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
1d693155	133
dd4c3919	134	stm_enable_irq(sensor);
1d693155	135
dd4c3919 PP	136	/* Acknoledge all DTS irqs */
dd4c3919 PP	137	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);
1d693155 DHS	138
	139	return IRQ_HANDLED;
	140	}
	141
	142	static int stm_sensor_power_on(struct stm_thermal_sensor *sensor)
	143	{
	144	int ret;
	145	u32 value;
	146
	147	/* Enable sensor */
	148	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
	149	value \|= TS1_EN;
	150	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
	151
	152	/*
	153	* The DTS block can be enabled by setting TSx_EN bit in
	154	* DTS_CFGRx register. It requires a startup time of
	155	* 40μs. Use 5 ms as arbitrary timeout.
	156	*/
	157	ret = readl_poll_timeout(sensor->base + DTS_SR_OFFSET,
	158	value, (value & TS_RDY),
	159	STARTUP_TIME, POLL_TIMEOUT);
	160	if (ret)
	161	return ret;
	162
	163	/* Start continuous measuring */
	164	value = readl_relaxed(sensor->base +
	165	DTS_CFGR1_OFFSET);
	166	value \|= TS1_START;
	167	writel_relaxed(value, sensor->base +
	168	DTS_CFGR1_OFFSET);
	169
d4a7e053 PP	170	sensor->mode = THERMAL_DEVICE_ENABLED;
d4a7e053 PP	171
1d693155 DHS	172	return 0;
	173	}
	174
	175	static int stm_sensor_power_off(struct stm_thermal_sensor *sensor)
	176	{
	177	u32 value;
	178
d4a7e053 PP	179	sensor->mode = THERMAL_DEVICE_DISABLED;
d4a7e053 PP	180
1d693155 DHS	181	/* Stop measuring */
	182	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
	183	value &= ~TS1_START;
	184	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
	185
	186	/* Ensure stop is taken into account */
	187	usleep_range(STARTUP_TIME, POLL_TIMEOUT);
	188
	189	/* Disable sensor */
	190	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
	191	value &= ~TS1_EN;
	192	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
	193
	194	/* Ensure disable is taken into account */
	195	return readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value,
	196	!(value & TS_RDY),
	197	STARTUP_TIME, POLL_TIMEOUT);
	198	}
	199
	200	static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
	201	{
	202	u32 value, clk_freq;
	203	u32 prescaler;
	204
	205	/* Figure out prescaler value for PCLK during calibration */
	206	clk_freq = clk_get_rate(sensor->clk);
	207	if (!clk_freq)
	208	return -EINVAL;
	209
	210	prescaler = 0;
	211	clk_freq /= ONE_MHZ;
	212	if (clk_freq) {
	213	while (prescaler <= clk_freq)
	214	prescaler++;
	215	}
	216
	217	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
	218
	219	/* Clear prescaler */
	220	value &= ~HSREF_CLK_DIV_MASK;
	221
	222	/* Set prescaler. pclk_freq/prescaler < 1MHz */
	223	value \|= (prescaler << HSREF_CLK_DIV_POS);
	224
	225	/* Select PCLK as reference clock */
	226	value &= ~REFCLK_SEL;
	227
	228	/* Set maximal sampling time for better precision */
	229	value \|= TS1_SMP_TIME_MASK;
	230
	231	/* Measure with calibration */
	232	value &= ~CALIBRATION_CONTROL;
	233
	234	/* select trigger */
	235	value &= ~TS1_INTRIG_SEL_MASK;
	236	value \|= NO_HW_TRIG;
	237
	238	writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET);
	239
	240	return 0;
	241	}
	242
	243	/* Fill in DTS structure with factory sensor values */
	244	static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor)
245	{
246	/* Retrieve engineering calibration temperature */
247	sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) &
248	TS1_T0_MASK;
249	if (!sensor->t0)
250	sensor->t0 = TS1_T0_VAL0;
251	else
252	sensor->t0 = TS1_T0_VAL1;
253
254	/* Retrieve fmt0 and put it on Hz */
99c47fcd DHS	255	sensor->fmt0 = ADJUST * (readl_relaxed(sensor->base +
99c47fcd DHS	256	DTS_T0VALR1_OFFSET) & TS1_FMT0_MASK);
1d693155 DHS	257
	258	/* Retrieve ramp coefficient */
	259	sensor->ramp_coeff = readl_relaxed(sensor->base + DTS_RAMPVALR_OFFSET) &
	260	TS1_RAMP_COEFF_MASK;
	261
	262	if (!sensor->fmt0 \|\| !sensor->ramp_coeff) {
	263	dev_err(sensor->dev, "%s: wrong setting\n", __func__);
	264	return -EINVAL;
	265	}
	266
	267	dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC",
	268	__func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff);
	269
	270	return 0;
	271	}
	272
	273	static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
	274	int temp, u32 *th)
	275	{
	276	int freqM;
1d693155 DHS	277
1d693155 DHS	278	/* Figure out the CLK_PTAT frequency for a given temperature */
9d8593f2 PP	279	freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 +
9d8593f2 PP	280	sensor->fmt0;
1d693155 DHS	281
1d693155 DHS	282	/* Figure out the threshold sample number */
9d8593f2	283	th = clk_get_rate(sensor->clk) SAMPLING_TIME / freqM;
1d693155 DHS	284	if (!*th)
	285	return -EINVAL;
	286
9d8593f2	287	dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th);
1d693155 DHS	288
	289	return 0;
	290	}
	291
1d693155 DHS	292	/* Disable temperature interrupt */
	293	static int stm_disable_irq(struct stm_thermal_sensor *sensor)
	294	{
	295	u32 value;
	296
1f64fa36	297	/* Disable IT generation */
1d693155	298	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
1f64fa36 PP	299	value &= ~ITENR_MASK;
1f64fa36 PP	300	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);
1d693155 DHS	301
	302	return 0;
	303	}
	304
dd4c3919	305	static int stm_thermal_set_trips(void *data, int low, int high)
1d693155	306	{
dd4c3919 PP	307	struct stm_thermal_sensor *sensor = data;
	308	u32 itr1, th;
	309	int ret;
1d693155	310
dd4c3919	311	dev_dbg(sensor->dev, "set trips %d <--> %d\n", low, high);
1d693155	312
dd4c3919 PP	313	/* Erase threshold content */
	314	itr1 = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
	315	itr1 &= ~(TS1_LITTHD_MASK \| TS1_HITTHD_MASK);
1d693155	316
dd4c3919 PP	317	/*
	318	* Disable low-temp if "low" is too small. As per thermal framework
	319	* API, we use -INT_MAX rather than INT_MIN.
	320	*/
1d693155	321
dd4c3919 PP	322	if (low > -INT_MAX) {
dd4c3919 PP	323	sensor->low_temp_enabled = 1;
2f23e319 PP	324	/* add 0.5 of hysteresis due to measurement error */
2f23e319 PP	325	ret = stm_thermal_calculate_threshold(sensor, low - 500, &th);
dd4c3919 PP	326	if (ret)
dd4c3919 PP	327	return ret;
1d693155	328
dd4c3919 PP	329	itr1 \|= (TS1_HITTHD_MASK & (th << TS1_HITTHD_POS));
	330	} else {
	331	sensor->low_temp_enabled = 0;
1d693155 DHS	332	}
1d693155 DHS	333
dd4c3919 PP	334	/* Disable high-temp if "high" is too big. */
	335	if (high < INT_MAX) {
	336	sensor->high_temp_enabled = 1;
	337	ret = stm_thermal_calculate_threshold(sensor, high, &th);
	338	if (ret)
	339	return ret;
1d693155	340
dd4c3919 PP	341	itr1 \|= (TS1_LITTHD_MASK & (th << TS1_LITTHD_POS));
	342	} else {
	343	sensor->high_temp_enabled = 0;
	344	}
1d693155	345
dd4c3919 PP	346	/* Write new threshod values*/
dd4c3919 PP	347	writel_relaxed(itr1, sensor->base + DTS_ITR1_OFFSET);
1d693155 DHS	348
	349	return 0;
	350	}
	351
	352	/* Callback to get temperature from HW */
	353	static int stm_thermal_get_temp(void data, int temp)
	354	{
	355	struct stm_thermal_sensor *sensor = data;
9d8593f2	356	u32 periods;
1d693155 DHS	357	int freqM, ret;
	358
	359	if (sensor->mode != THERMAL_DEVICE_ENABLED)
	360	return -EAGAIN;
	361
9d8593f2 PP	362	/* Retrieve the number of periods sampled */
	363	ret = readl_relaxed_poll_timeout(sensor->base + DTS_DR_OFFSET, periods,
	364	(periods & TS1_MFREQ_MASK),
	365	STARTUP_TIME, POLL_TIMEOUT);
1d693155 DHS	366	if (ret)
	367	return ret;
	368
1d693155	369	/* Figure out the CLK_PTAT frequency */
9d8593f2	370	freqM = (clk_get_rate(sensor->clk) * SAMPLING_TIME) / periods;
1d693155 DHS	371	if (!freqM)
	372	return -EINVAL;
	373
1d693155	374	/* Figure out the temperature in mili celsius */
9d8593f2	375	temp = (freqM - sensor->fmt0) 1000 / sensor->ramp_coeff + sensor->t0;
1d693155	376
1d693155 DHS	377	return 0;
	378	}
	379
	380	/* Registers DTS irq to be visible by GIC */
	381	static int stm_register_irq(struct stm_thermal_sensor *sensor)
	382	{
	383	struct device *dev = sensor->dev;
	384	struct platform_device *pdev = to_platform_device(dev);
	385	int ret;
	386
	387	sensor->irq = platform_get_irq(pdev, 0);
8cb775bb	388	if (sensor->irq < 0)
1d693155	389	return sensor->irq;
1d693155 DHS	390
1d693155 DHS	391	ret = devm_request_threaded_irq(dev, sensor->irq,
dd4c3919 PP	392	NULL,
dd4c3919 PP	393	stm_thermal_irq_handler,
1d693155 DHS	394	IRQF_ONESHOT,
	395	dev->driver->name, sensor);
	396	if (ret) {
	397	dev_err(dev, "%s: Failed to register IRQ %d\n", __func__,
	398	sensor->irq);
	399	return ret;
	400	}
	401
1d693155 DHS	402	dev_dbg(dev, "%s: thermal IRQ registered", __func__);
	403
	404	return 0;
	405	}
	406
	407	static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
	408	{
	409	int ret;
	410
dd4c3919 PP	411	stm_disable_irq(sensor);
dd4c3919 PP	412
1d693155 DHS	413	ret = stm_sensor_power_off(sensor);
	414	if (ret)
	415	return ret;
	416
	417	clk_disable_unprepare(sensor->clk);
	418
	419	return 0;
	420	}
	421
	422	static int stm_thermal_prepare(struct stm_thermal_sensor *sensor)
	423	{
	424	int ret;
1d693155 DHS	425
	426	ret = clk_prepare_enable(sensor->clk);
	427	if (ret)
	428	return ret;
	429
3c9d0820 DHS	430	ret = stm_thermal_read_factory_settings(sensor);
	431	if (ret)
	432	goto thermal_unprepare;
	433
1d693155 DHS	434	ret = stm_thermal_calibration(sensor);
	435	if (ret)
	436	goto thermal_unprepare;
	437
1d693155 DHS	438	return 0;
1d693155 DHS	439
1d693155 DHS	440	thermal_unprepare:
	441	clk_disable_unprepare(sensor->clk);
	442
	443	return ret;
	444	}
	445
	446	#ifdef CONFIG_PM_SLEEP
	447	static int stm_thermal_suspend(struct device *dev)
	448	{
df535485	449	struct stm_thermal_sensor *sensor = dev_get_drvdata(dev);
1d693155	450
be52a196	451	return stm_thermal_sensor_off(sensor);
1d693155 DHS	452	}
	453
	454	static int stm_thermal_resume(struct device *dev)
	455	{
	456	int ret;
df535485	457	struct stm_thermal_sensor *sensor = dev_get_drvdata(dev);
1d693155 DHS	458
	459	ret = stm_thermal_prepare(sensor);
	460	if (ret)
	461	return ret;
	462
dd4c3919 PP	463	ret = stm_sensor_power_on(sensor);
	464	if (ret)
	465	return ret;
	466
	467	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
	468	stm_enable_irq(sensor);
1d693155 DHS	469
	470	return 0;
	471	}
	472	#endif /* CONFIG_PM_SLEEP */
	473
afa58b49 CW	474	static SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops,
afa58b49 CW	475	stm_thermal_suspend, stm_thermal_resume);
1d693155 DHS	476
	477	static const struct thermal_zone_of_device_ops stm_tz_ops = {
	478	.get_temp = stm_thermal_get_temp,
dd4c3919	479	.set_trips = stm_thermal_set_trips,
1d693155 DHS	480	};
	481
	482	static const struct of_device_id stm_thermal_of_match[] = {
	483	{ .compatible = "st,stm32-thermal"},
	484	{ /* sentinel */ }
	485	};
	486	MODULE_DEVICE_TABLE(of, stm_thermal_of_match);
	487
	488	static int stm_thermal_probe(struct platform_device *pdev)
	489	{
	490	struct stm_thermal_sensor *sensor;
	491	struct resource *res;
1d693155	492	void __iomem *base;
dd4c3919	493	int ret;
1d693155 DHS	494
	495	if (!pdev->dev.of_node) {
	496	dev_err(&pdev->dev, "%s: device tree node not found\n",
	497	__func__);
	498	return -EINVAL;
	499	}
	500
	501	sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL);
	502	if (!sensor)
	503	return -ENOMEM;
	504
	505	platform_set_drvdata(pdev, sensor);
	506
	507	sensor->dev = &pdev->dev;
	508
	509	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	510	base = devm_ioremap_resource(&pdev->dev, res);
	511	if (IS_ERR(base))
	512	return PTR_ERR(base);
	513
	514	/* Populate sensor */
	515	sensor->base = base;
	516
1d693155 DHS	517	sensor->clk = devm_clk_get(&pdev->dev, "pclk");
	518	if (IS_ERR(sensor->clk)) {
	519	dev_err(&pdev->dev, "%s: failed to fetch PCLK clock\n",
	520	__func__);
	521	return PTR_ERR(sensor->clk);
	522	}
	523
1f64fa36 PP	524	stm_disable_irq(sensor);
	525
	526	/* Clear irq flags */
	527	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);
	528
dd4c3919 PP	529	/* Configure and enable HW sensor */
	530	ret = stm_thermal_prepare(sensor);
	531	if (ret) {
8c173d5e	532	dev_err(&pdev->dev, "Error prepare sensor: %d\n", ret);
1d693155	533	return ret;
dd4c3919 PP	534	}
	535
	536	ret = stm_sensor_power_on(sensor);
	537	if (ret) {
	538	dev_err(&pdev->dev, "Error power on sensor: %d\n", ret);
	539	return ret;
	540	}
1d693155 DHS	541
	542	sensor->th_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
	543	sensor,
	544	&stm_tz_ops);
	545
	546	if (IS_ERR(sensor->th_dev)) {
	547	dev_err(&pdev->dev, "%s: thermal zone sensor registering KO\n",
	548	__func__);
	549	ret = PTR_ERR(sensor->th_dev);
	550	return ret;
	551	}
	552
dd4c3919 PP	553	/* Register IRQ into GIC */
	554	ret = stm_register_irq(sensor);
	555	if (ret)
1d693155	556	goto err_tz;
1d693155	557
dd4c3919	558	stm_enable_irq(sensor);
1d693155 DHS	559
	560	/*
	561	* Thermal_zone doesn't enable hwmon as default,
	562	* enable it here
	563	*/
	564	sensor->th_dev->tzp->no_hwmon = false;
	565	ret = thermal_add_hwmon_sysfs(sensor->th_dev);
	566	if (ret)
	567	goto err_tz;
	568
1d693155 DHS	569	dev_info(&pdev->dev, "%s: Driver initialized successfully\n",
	570	__func__);
	571
	572	return 0;
	573
	574	err_tz:
	575	thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
	576	return ret;
	577	}
	578
	579	static int stm_thermal_remove(struct platform_device *pdev)
	580	{
	581	struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev);
	582
	583	stm_thermal_sensor_off(sensor);
	584	thermal_remove_hwmon_sysfs(sensor->th_dev);
	585	thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev);
	586
	587	return 0;
	588	}
	589
	590	static struct platform_driver stm_thermal_driver = {
	591	.driver = {
	592	.name = "stm_thermal",
	593	.pm = &stm_thermal_pm_ops,
	594	.of_match_table = stm_thermal_of_match,
	595	},
	596	.probe = stm_thermal_probe,
	597	.remove = stm_thermal_remove,
	598	};
	599	module_platform_driver(stm_thermal_driver);
	600
	601	MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver");
	602	MODULE_AUTHOR("David Hernandez Sanchez <david.hernandezsanchez@st.com>");
	603	MODULE_LICENSE("GPL v2");
	604	MODULE_ALIAS("platform:stm_thermal");