drivers/thermal/rcar_gen3_thermal.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  *  R-Car Gen3 THS thermal sensor driver
  *  Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen.
  *
  * Copyright (C) 2016 Renesas Electronics Corporation.
  * Copyright (C) 2016 Sang Engineering
  *
  *  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; version 2 of the License.
  *
  *  This program is distributed in the hope that it will be useful, but
  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  General Public License for more details.
  *
  */
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spinlock.h>
 #include <linux/thermal.h>

 #include "thermal_core.h"

 /* Register offsets */
 #define REG_GEN3_IRQSTR		0x04
 #define REG_GEN3_IRQMSK		0x08
 #define REG_GEN3_IRQCTL		0x0C
 #define REG_GEN3_IRQEN		0x10
 #define REG_GEN3_IRQTEMP1	0x14
 #define REG_GEN3_IRQTEMP2	0x18
 #define REG_GEN3_IRQTEMP3	0x1C
 #define REG_GEN3_CTSR		0x20
 #define REG_GEN3_THCTR		0x20
 #define REG_GEN3_TEMP		0x28
 #define REG_GEN3_THCODE1	0x50
 #define REG_GEN3_THCODE2	0x54
 #define REG_GEN3_THCODE3	0x58

 /* IRQ{STR,MSK,EN} bits */
 #define IRQ_TEMP1		BIT(0)
 #define IRQ_TEMP2		BIT(1)
 #define IRQ_TEMP3		BIT(2)
 #define IRQ_TEMPD1		BIT(3)
 #define IRQ_TEMPD2		BIT(4)
 #define IRQ_TEMPD3		BIT(5)

 /* CTSR bits */
 #define CTSR_PONM	BIT(8)
 #define CTSR_AOUT	BIT(7)
 #define CTSR_THBGR	BIT(5)
 #define CTSR_VMEN	BIT(4)
 #define CTSR_VMST	BIT(1)
 #define CTSR_THSST	BIT(0)

 /* THCTR bits */
 #define THCTR_PONM	BIT(6)
 #define THCTR_THSST	BIT(0)

 #define CTEMP_MASK	0xFFF

 #define MCELSIUS(temp)	((temp) * 1000)
 #define GEN3_FUSE_MASK	0xFFF

 #define TSC_MAX_NUM	3

 /* Structure for thermal temperature calculation */
 struct equation_coefs {
 	int a1;
 	int b1;
 	int a2;
 	int b2;
 };

 struct rcar_gen3_thermal_tsc {
 	void __iomem *base;
 	struct thermal_zone_device *zone;
 	struct equation_coefs coef;
 	int low;
 	int high;
 };

 struct rcar_gen3_thermal_priv {
 	struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
 	unsigned int num_tscs;
 	spinlock_t lock; /* Protect interrupts on and off */
 	const struct rcar_gen3_thermal_data *data;
 };

 struct rcar_gen3_thermal_data {
 	void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
 };

 static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
 					 u32 reg)
 {
 	return ioread32(tsc->base + reg);
 }

 static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
 					   u32 reg, u32 data)
 {
 	iowrite32(data, tsc->base + reg);
 }

 /*
  * Linear approximation for temperature
  *
  * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
  *
  * The constants a and b are calculated using two triplets of int values PTAT
  * and THCODE. PTAT and THCODE can either be read from hardware or use hard
  * coded values from driver. The formula to calculate a and b are taken from
  * BSP and sparsely documented and understood.
  *
  * Examining the linear formula and the formula used to calculate constants a
  * and b while knowing that the span for PTAT and THCODE values are between
  * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
  * Integer also needs to be signed so that leaves 7 bits for binary
  * fixed point scaling.
  */

 #define FIXPT_SHIFT 7
 #define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
 #define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
 #define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
 #define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)

 #define RCAR3_THERMAL_GRAN 500 /* mili Celsius */

 /* no idea where these constants come from */
 #define TJ_1 96
 #define TJ_3 -41

 static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
 					 int *ptat, int *thcode)
 {
 	int tj_2;

 	/* TODO: Find documentation and document constant calculation formula */

 	/*
 	 * Division is not scaled in BSP and if scaled it might overflow
 	 * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
 	 */
 	tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 137)
 		/ (ptat[0] - ptat[2])) - FIXPT_INT(41);

 	coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
 			     tj_2 - FIXPT_INT(TJ_3));
 	coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;

 	coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
 			     tj_2 - FIXPT_INT(TJ_1));
 	coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
 }

 static int rcar_gen3_thermal_round(int temp)
 {
 	int result, round_offs;

 	round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
 		-RCAR3_THERMAL_GRAN / 2;
 	result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
 	return result * RCAR3_THERMAL_GRAN;
 }

 static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 {
 	struct rcar_gen3_thermal_tsc *tsc = devdata;
 	int mcelsius, val1, val2;
 	u32 reg;

 	/* Read register and convert to mili Celsius */
 	reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;

 	val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
 	val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
 	mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);

 	/* Make sure we are inside specifications */
 	if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125)))
 		return -EIO;

 	/* Round value to device granularity setting */
 	*temp = rcar_gen3_thermal_round(mcelsius);

 	return 0;
 }

 static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
 					      int mcelsius)
 {
 	int celsius, val1, val2;

 	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
 	val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
 	val2 = celsius * tsc->coef.a2 + tsc->coef.b2;

 	return INT_FIXPT((val1 + val2) / 2);
 }

 static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
 {
 	struct rcar_gen3_thermal_tsc *tsc = devdata;

 	low = clamp_val(low, -40000, 125000);
 	high = clamp_val(high, -40000, 125000);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
 				rcar_gen3_thermal_mcelsius_to_temp(tsc, low));

 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
 				rcar_gen3_thermal_mcelsius_to_temp(tsc, high));

 	tsc->low = low;
 	tsc->high = high;

 	return 0;
 }

 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 	.get_temp	= rcar_gen3_thermal_get_temp,
 	.set_trips	= rcar_gen3_thermal_set_trips,
 };

 static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
 {
 	unsigned int i;
 	u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;

 	for (i = 0; i < priv->num_tscs; i++)
 		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
 }

 static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 {
 	struct rcar_gen3_thermal_priv *priv = data;
 	u32 status;
 	int i, ret = IRQ_HANDLED;

 	spin_lock(&priv->lock);
 	for (i = 0; i < priv->num_tscs; i++) {
 		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 		if (status)
 			ret = IRQ_WAKE_THREAD;
 	}

 	if (ret == IRQ_WAKE_THREAD)
 		rcar_thermal_irq_set(priv, false);

 	spin_unlock(&priv->lock);

 	return ret;
 }

 static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
 {
 	struct rcar_gen3_thermal_priv *priv = data;
 	unsigned long flags;
 	int i;

 	for (i = 0; i < priv->num_tscs; i++)
 		thermal_zone_device_update(priv->tscs[i]->zone,
 					   THERMAL_EVENT_UNSPECIFIED);

 	spin_lock_irqsave(&priv->lock, flags);
 	rcar_thermal_irq_set(priv, true);
 	spin_unlock_irqrestore(&priv->lock, flags);

 	return IRQ_HANDLED;
 }

 static void r8a7795_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 {
 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  CTSR_THBGR);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,  0x0);

 	usleep_range(1000, 2000);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);

 	usleep_range(100, 200);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
 				CTSR_VMST | CTSR_THSST);

 	usleep_range(1000, 2000);
 }

 static void r8a7796_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 {
 	u32 reg_val;

 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 	reg_val &= ~THCTR_PONM;
 	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);

 	usleep_range(1000, 2000);

 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);

 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 	reg_val |= THCTR_THSST;
 	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);

 	usleep_range(1000, 2000);
 }

 static const struct rcar_gen3_thermal_data r8a7795_data = {
 	.thermal_init = r8a7795_thermal_init,
 };

 static const struct rcar_gen3_thermal_data r8a7796_data = {
 	.thermal_init = r8a7796_thermal_init,
 };

 static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
 	{ .compatible = "renesas,r8a7795-thermal", .data = &r8a7795_data},
 	{ .compatible = "renesas,r8a7796-thermal", .data = &r8a7796_data},
 	{},
 };
 MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);

 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);

 	rcar_thermal_irq_set(priv, false);

 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);

 	return 0;
 }

 static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 {
 	struct rcar_gen3_thermal_priv *priv;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
 	struct thermal_zone_device *zone;
 	int ret, irq, i;
 	char *irqname;

 	/* default values if FUSEs are missing */
 	/* TODO: Read values from hardware on supported platforms */
 	int ptat[3] = { 2351, 1509, 435 };
 	int thcode[TSC_MAX_NUM][3] = {
 		{ 3248, 2800, 2221 },
 		{ 3245, 2795, 2216 },
 		{ 3250, 2805, 2237 },
 	};

 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	priv->data = of_device_get_match_data(dev);

 	spin_lock_init(&priv->lock);

 	platform_set_drvdata(pdev, priv);

 	/*
 	 * Request 2 (of the 3 possible) IRQs, the driver only needs to
 	 * to trigger on the low and high trip points of the current
 	 * temp window at this point.
 	 */
 	for (i = 0; i < 2; i++) {
 		irq = platform_get_irq(pdev, i);
 		if (irq < 0)
 			return irq;

 		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
 					 dev_name(dev), i);
 		if (!irqname)
 			return -ENOMEM;

 		ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
 						rcar_gen3_thermal_irq_thread,
 						IRQF_SHARED, irqname, priv);
 		if (ret)
 			return ret;
 	}

 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);

 	for (i = 0; i < TSC_MAX_NUM; i++) {
 		struct rcar_gen3_thermal_tsc *tsc;

 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 		if (!res)
 			break;

 		tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
 		if (!tsc) {
 			ret = -ENOMEM;
 			goto error_unregister;
 		}

 		tsc->base = devm_ioremap_resource(dev, res);
 		if (IS_ERR(tsc->base)) {
 			ret = PTR_ERR(tsc->base);
 			goto error_unregister;
 		}

 		priv->tscs[i] = tsc;

 		priv->data->thermal_init(tsc);
 		rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);

 		zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
 							    &rcar_gen3_tz_of_ops);
 		if (IS_ERR(zone)) {
 			dev_err(dev, "Can't register thermal zone\n");
 			ret = PTR_ERR(zone);
 			goto error_unregister;
 		}
 		tsc->zone = zone;

 		ret = of_thermal_get_ntrips(tsc->zone);
 		if (ret < 0)
 			goto error_unregister;

 		dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 	}

 	priv->num_tscs = i;

 	if (!priv->num_tscs) {
 		ret = -ENODEV;
 		goto error_unregister;
 	}

 	rcar_thermal_irq_set(priv, true);

 	return 0;

 error_unregister:
 	rcar_gen3_thermal_remove(pdev);

 	return ret;
 }

 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 {
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);

 	rcar_thermal_irq_set(priv, false);

 	return 0;
 }

 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 {
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 	unsigned int i;

 	for (i = 0; i < priv->num_tscs; i++) {
 		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];

 		priv->data->thermal_init(tsc);
 		rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
 	}

 	rcar_thermal_irq_set(priv, true);

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
 			 rcar_gen3_thermal_resume);

 static struct platform_driver rcar_gen3_thermal_driver = {
 	.driver	= {
 		.name	= "rcar_gen3_thermal",
 		.pm = &rcar_gen3_thermal_pm_ops,
 		.of_match_table = rcar_gen3_thermal_dt_ids,
 	},
 	.probe		= rcar_gen3_thermal_probe,
 	.remove		= rcar_gen3_thermal_remove,
 };
 module_platform_driver(rcar_gen3_thermal_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
 MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
	/*
	* R-Car Gen3 THS thermal sensor driver
	* Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen.
	*
	* Copyright (C) 2016 Renesas Electronics Corporation.
	* Copyright (C) 2016 Sang Engineering
	*
	* 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; version 2 of the License.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	*/
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/spinlock.h>
	#include <linux/thermal.h>

	#include "thermal_core.h"

	/* Register offsets */
	#define REG_GEN3_IRQSTR 0x04
	#define REG_GEN3_IRQMSK 0x08
	#define REG_GEN3_IRQCTL 0x0C
	#define REG_GEN3_IRQEN 0x10
	#define REG_GEN3_IRQTEMP1 0x14
	#define REG_GEN3_IRQTEMP2 0x18
	#define REG_GEN3_IRQTEMP3 0x1C
	#define REG_GEN3_CTSR 0x20
	#define REG_GEN3_THCTR 0x20
	#define REG_GEN3_TEMP 0x28
	#define REG_GEN3_THCODE1 0x50
	#define REG_GEN3_THCODE2 0x54
	#define REG_GEN3_THCODE3 0x58

	/* IRQ{STR,MSK,EN} bits */
	#define IRQ_TEMP1 BIT(0)
	#define IRQ_TEMP2 BIT(1)
	#define IRQ_TEMP3 BIT(2)
	#define IRQ_TEMPD1 BIT(3)
	#define IRQ_TEMPD2 BIT(4)
	#define IRQ_TEMPD3 BIT(5)

	/* CTSR bits */
	#define CTSR_PONM BIT(8)
	#define CTSR_AOUT BIT(7)
	#define CTSR_THBGR BIT(5)
	#define CTSR_VMEN BIT(4)
	#define CTSR_VMST BIT(1)
	#define CTSR_THSST BIT(0)

	/* THCTR bits */
	#define THCTR_PONM BIT(6)
	#define THCTR_THSST BIT(0)

	#define CTEMP_MASK 0xFFF

	#define MCELSIUS(temp) ((temp) * 1000)
	#define GEN3_FUSE_MASK 0xFFF

	#define TSC_MAX_NUM 3

	/* Structure for thermal temperature calculation */
	struct equation_coefs {
	int a1;
	int b1;
	int a2;
	int b2;
	};

	struct rcar_gen3_thermal_tsc {
	void __iomem *base;
	struct thermal_zone_device *zone;
	struct equation_coefs coef;
	int low;
	int high;
	};

	struct rcar_gen3_thermal_priv {
	struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
	unsigned int num_tscs;
	spinlock_t lock; /* Protect interrupts on and off */
	const struct rcar_gen3_thermal_data *data;
	};

	struct rcar_gen3_thermal_data {
	void (thermal_init)(struct rcar_gen3_thermal_tsc tsc);
	};

	static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
	u32 reg)
	{
	return ioread32(tsc->base + reg);
	}

	static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
	u32 reg, u32 data)
	{
	iowrite32(data, tsc->base + reg);
	}

	/*
	* Linear approximation for temperature
	*
	* [reg] = [temp] * a + b => [temp] = ([reg] - b) / a
	*
	* The constants a and b are calculated using two triplets of int values PTAT
	* and THCODE. PTAT and THCODE can either be read from hardware or use hard
	* coded values from driver. The formula to calculate a and b are taken from
	* BSP and sparsely documented and understood.
	*
	* Examining the linear formula and the formula used to calculate constants a
	* and b while knowing that the span for PTAT and THCODE values are between
	* 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
	* Integer also needs to be signed so that leaves 7 bits for binary
	* fixed point scaling.
	*/

	#define FIXPT_SHIFT 7
	#define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
	#define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
	#define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
	#define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)

	#define RCAR3_THERMAL_GRAN 500 /* mili Celsius */

	/* no idea where these constants come from */
	#define TJ_1 96
	#define TJ_3 -41

	static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef,
	int ptat, int thcode)
	{
	int tj_2;

	/* TODO: Find documentation and document constant calculation formula */

	/*
	* Division is not scaled in BSP and if scaled it might overflow
	* the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
	*/
	tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 137)
	/ (ptat[0] - ptat[2])) - FIXPT_INT(41);

	coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
	tj_2 - FIXPT_INT(TJ_3));
	coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3;

	coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
	tj_2 - FIXPT_INT(TJ_1));
	coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1;
	}

	static int rcar_gen3_thermal_round(int temp)
	{
	int result, round_offs;

	round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
	-RCAR3_THERMAL_GRAN / 2;
	result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
	return result * RCAR3_THERMAL_GRAN;
	}

	static int rcar_gen3_thermal_get_temp(void devdata, int temp)
	{
	struct rcar_gen3_thermal_tsc *tsc = devdata;
	int mcelsius, val1, val2;
	u32 reg;

	/* Read register and convert to mili Celsius */
	reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;

	val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1);
	val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2);
	mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2);

	/* Make sure we are inside specifications */
	if ((mcelsius < MCELSIUS(-40)) \|\| (mcelsius > MCELSIUS(125)))
	return -EIO;

	/* Round value to device granularity setting */
	*temp = rcar_gen3_thermal_round(mcelsius);

	return 0;
	}

	static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
	int mcelsius)
	{
	int celsius, val1, val2;

	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
	val1 = celsius * tsc->coef.a1 + tsc->coef.b1;
	val2 = celsius * tsc->coef.a2 + tsc->coef.b2;

	return INT_FIXPT((val1 + val2) / 2);
	}

	static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high)
	{
	struct rcar_gen3_thermal_tsc *tsc = devdata;

	low = clamp_val(low, -40000, 125000);
	high = clamp_val(high, -40000, 125000);

	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
	rcar_gen3_thermal_mcelsius_to_temp(tsc, low));

	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
	rcar_gen3_thermal_mcelsius_to_temp(tsc, high));

	tsc->low = low;
	tsc->high = high;

	return 0;
	}

	static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
	.get_temp = rcar_gen3_thermal_get_temp,
	.set_trips = rcar_gen3_thermal_set_trips,
	};

	static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
	{
	unsigned int i;
	u32 val = on ? IRQ_TEMPD1 \| IRQ_TEMP2 : 0;

	for (i = 0; i < priv->num_tscs; i++)
	rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
	}

	static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
	{
	struct rcar_gen3_thermal_priv *priv = data;
	u32 status;
	int i, ret = IRQ_HANDLED;

	spin_lock(&priv->lock);
	for (i = 0; i < priv->num_tscs; i++) {
	status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
	rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
	if (status)
	ret = IRQ_WAKE_THREAD;
	}

	if (ret == IRQ_WAKE_THREAD)
	rcar_thermal_irq_set(priv, false);

	spin_unlock(&priv->lock);

	return ret;
	}

	static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
	{
	struct rcar_gen3_thermal_priv *priv = data;
	unsigned long flags;
	int i;

	for (i = 0; i < priv->num_tscs; i++)
	thermal_zone_device_update(priv->tscs[i]->zone,
	THERMAL_EVENT_UNSPECIFIED);

	spin_lock_irqsave(&priv->lock, flags);
	rcar_thermal_irq_set(priv, true);
	spin_unlock_irqrestore(&priv->lock, flags);

	return IRQ_HANDLED;
	}

	static void r8a7795_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
	{
	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_THBGR);
	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, 0x0);

	usleep_range(1000, 2000);

	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);

	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 \| IRQ_TEMP2);

	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
	CTSR_PONM \| CTSR_AOUT \| CTSR_THBGR \| CTSR_VMEN);

	usleep_range(100, 200);

	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
	CTSR_PONM \| CTSR_AOUT \| CTSR_THBGR \| CTSR_VMEN \|
	CTSR_VMST \| CTSR_THSST);

	usleep_range(1000, 2000);
	}

	static void r8a7796_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
	{
	u32 reg_val;

	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
	reg_val &= ~THCTR_PONM;
	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);

	usleep_range(1000, 2000);

	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 \| IRQ_TEMP2);

	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
	reg_val \|= THCTR_THSST;
	rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);

	usleep_range(1000, 2000);
	}

	static const struct rcar_gen3_thermal_data r8a7795_data = {
	.thermal_init = r8a7795_thermal_init,
	};

	static const struct rcar_gen3_thermal_data r8a7796_data = {
	.thermal_init = r8a7796_thermal_init,
	};

	static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
	{ .compatible = "renesas,r8a7795-thermal", .data = &r8a7795_data},
	{ .compatible = "renesas,r8a7796-thermal", .data = &r8a7796_data},
	{},
	};
	MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);

	static int rcar_gen3_thermal_remove(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);

	rcar_thermal_irq_set(priv, false);

	pm_runtime_put(dev);
	pm_runtime_disable(dev);

	return 0;
	}

	static int rcar_gen3_thermal_probe(struct platform_device *pdev)
	{
	struct rcar_gen3_thermal_priv *priv;
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct thermal_zone_device *zone;
	int ret, irq, i;
	char *irqname;

	/* default values if FUSEs are missing */
	/* TODO: Read values from hardware on supported platforms */
	int ptat[3] = { 2351, 1509, 435 };
	int thcode[TSC_MAX_NUM][3] = {
	{ 3248, 2800, 2221 },
	{ 3245, 2795, 2216 },
	{ 3250, 2805, 2237 },
	};

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	priv->data = of_device_get_match_data(dev);

	spin_lock_init(&priv->lock);

	platform_set_drvdata(pdev, priv);

	/*
	* Request 2 (of the 3 possible) IRQs, the driver only needs to
	* to trigger on the low and high trip points of the current
	* temp window at this point.
	*/
	for (i = 0; i < 2; i++) {
	irq = platform_get_irq(pdev, i);
	if (irq < 0)
	return irq;

	irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
	dev_name(dev), i);
	if (!irqname)
	return -ENOMEM;

	ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
	rcar_gen3_thermal_irq_thread,
	IRQF_SHARED, irqname, priv);
	if (ret)
	return ret;
	}

	pm_runtime_enable(dev);
	pm_runtime_get_sync(dev);

	for (i = 0; i < TSC_MAX_NUM; i++) {
	struct rcar_gen3_thermal_tsc *tsc;

	res = platform_get_resource(pdev, IORESOURCE_MEM, i);
	if (!res)
	break;

	tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
	if (!tsc) {
	ret = -ENOMEM;
	goto error_unregister;
	}

	tsc->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(tsc->base)) {
	ret = PTR_ERR(tsc->base);
	goto error_unregister;
	}

	priv->tscs[i] = tsc;

	priv->data->thermal_init(tsc);
	rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]);

	zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
	&rcar_gen3_tz_of_ops);
	if (IS_ERR(zone)) {
	dev_err(dev, "Can't register thermal zone\n");
	ret = PTR_ERR(zone);
	goto error_unregister;
	}
	tsc->zone = zone;

	ret = of_thermal_get_ntrips(tsc->zone);
	if (ret < 0)
	goto error_unregister;

	dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
	}

	priv->num_tscs = i;

	if (!priv->num_tscs) {
	ret = -ENODEV;
	goto error_unregister;
	}

	rcar_thermal_irq_set(priv, true);

	return 0;

	error_unregister:
	rcar_gen3_thermal_remove(pdev);

	return ret;
	}

	static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
	{
	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);

	rcar_thermal_irq_set(priv, false);

	return 0;
	}

	static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
	{
	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
	unsigned int i;

	for (i = 0; i < priv->num_tscs; i++) {
	struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];

	priv->data->thermal_init(tsc);
	rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high);
	}

	rcar_thermal_irq_set(priv, true);

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
	rcar_gen3_thermal_resume);

	static struct platform_driver rcar_gen3_thermal_driver = {
	.driver = {
	.name = "rcar_gen3_thermal",
	.pm = &rcar_gen3_thermal_pm_ops,
	.of_match_table = rcar_gen3_thermal_dt_ids,
	},
	.probe = rcar_gen3_thermal_probe,
	.remove = rcar_gen3_thermal_remove,
	};
	module_platform_driver(rcar_gen3_thermal_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
	MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");