/*
 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/thermal.h>

/**
 * If the temperature over a period of time High,
 * the resulting TSHUT gave CRU module,let it reset the entire chip,
 * or via GPIO give PMIC.
 */
enum tshut_mode {
	TSHUT_MODE_CRU = 0,
	TSHUT_MODE_GPIO,
};

/**
 * the system Temperature Sensors tshut(tshut) polarity
 * the bit 8 is tshut polarity.
 * 0: low active, 1: high active
 */
enum tshut_polarity {
	TSHUT_LOW_ACTIVE = 0,
	TSHUT_HIGH_ACTIVE,
};

/**
 * The system has three Temperature Sensors.  channel 0 is reserved,
 * channel 1 is for CPU, and channel 2 is for GPU.
 */
enum sensor_id {
	SENSOR_CPU = 1,
	SENSOR_GPU,
};

struct rockchip_tsadc_chip {
	/* The hardware-controlled tshut property */
	long tshut_temp;
	enum tshut_mode tshut_mode;
	enum tshut_polarity tshut_polarity;

	/* Chip-wide methods */
	void (*initialize)(void __iomem *reg, enum tshut_polarity p);
	void (*irq_ack)(void __iomem *reg);
	void (*control)(void __iomem *reg, bool on);

	/* Per-sensor methods */
	int (*get_temp)(int chn, void __iomem *reg, int *temp);
	void (*set_tshut_temp)(int chn, void __iomem *reg, long temp);
	void (*set_tshut_mode)(int chn, void __iomem *reg, enum tshut_mode m);
};

struct rockchip_thermal_sensor {
	struct rockchip_thermal_data *thermal;
	struct thermal_zone_device *tzd;
	enum sensor_id id;
};

#define NUM_SENSORS	2 /* Ignore unused sensor 0 */

struct rockchip_thermal_data {
	const struct rockchip_tsadc_chip *chip;
	struct platform_device *pdev;
	struct reset_control *reset;

	struct rockchip_thermal_sensor sensors[NUM_SENSORS];

	struct clk *clk;
	struct clk *pclk;

	void __iomem *regs;

	long tshut_temp;
	enum tshut_mode tshut_mode;
	enum tshut_polarity tshut_polarity;
};

/* TSADC V2 Sensor info define: */
#define TSADCV2_AUTO_CON			0x04
#define TSADCV2_INT_EN				0x08
#define TSADCV2_INT_PD				0x0c
#define TSADCV2_DATA(chn)			(0x20 + (chn) * 0x04)
#define TSADCV2_COMP_SHUT(chn)		        (0x40 + (chn) * 0x04)
#define TSADCV2_HIGHT_INT_DEBOUNCE		0x60
#define TSADCV2_HIGHT_TSHUT_DEBOUNCE		0x64
#define TSADCV2_AUTO_PERIOD			0x68
#define TSADCV2_AUTO_PERIOD_HT			0x6c

#define TSADCV2_AUTO_EN				BIT(0)
#define TSADCV2_AUTO_DISABLE			~BIT(0)
#define TSADCV2_AUTO_SRC_EN(chn)		BIT(4 + (chn))
#define TSADCV2_AUTO_TSHUT_POLARITY_HIGH	BIT(8)
#define TSADCV2_AUTO_TSHUT_POLARITY_LOW		~BIT(8)

#define TSADCV2_INT_SRC_EN(chn)			BIT(chn)
#define TSADCV2_SHUT_2GPIO_SRC_EN(chn)		BIT(4 + (chn))
#define TSADCV2_SHUT_2CRU_SRC_EN(chn)		BIT(8 + (chn))

#define TSADCV2_INT_PD_CLEAR			~BIT(8)

#define TSADCV2_DATA_MASK			0xfff
#define TSADCV2_HIGHT_INT_DEBOUNCE_COUNT	4
#define TSADCV2_HIGHT_TSHUT_DEBOUNCE_COUNT	4
#define TSADCV2_AUTO_PERIOD_TIME		250 /* msec */
#define TSADCV2_AUTO_PERIOD_HT_TIME		50  /* msec */

struct tsadc_table {
	unsigned long code;
	long temp;
};

static const struct tsadc_table v2_code_table[] = {
	{TSADCV2_DATA_MASK, -40000},
	{3800, -40000},
	{3792, -35000},
	{3783, -30000},
	{3774, -25000},
	{3765, -20000},
	{3756, -15000},
	{3747, -10000},
	{3737, -5000},
	{3728, 0},
	{3718, 5000},
	{3708, 10000},
	{3698, 15000},
	{3688, 20000},
	{3678, 25000},
	{3667, 30000},
	{3656, 35000},
	{3645, 40000},
	{3634, 45000},
	{3623, 50000},
	{3611, 55000},
	{3600, 60000},
	{3588, 65000},
	{3575, 70000},
	{3563, 75000},
	{3550, 80000},
	{3537, 85000},
	{3524, 90000},
	{3510, 95000},
	{3496, 100000},
	{3482, 105000},
	{3467, 110000},
	{3452, 115000},
	{3437, 120000},
	{3421, 125000},
	{0, 125000},
};

static u32 rk_tsadcv2_temp_to_code(long temp)
{
	int high, low, mid;

	low = 0;
	high = ARRAY_SIZE(v2_code_table) - 1;
	mid = (high + low) / 2;

	if (temp < v2_code_table[low].temp || temp > v2_code_table[high].temp)
		return 0;

	while (low <= high) {
		if (temp == v2_code_table[mid].temp)
			return v2_code_table[mid].code;
		else if (temp < v2_code_table[mid].temp)
			high = mid - 1;
		else
			low = mid + 1;
		mid = (low + high) / 2;
	}

	return 0;
}

static int rk_tsadcv2_code_to_temp(u32 code)
{
	unsigned int low = 0;
	unsigned int high = ARRAY_SIZE(v2_code_table) - 1;
	unsigned int mid = (low + high) / 2;
	unsigned int num;
	unsigned long denom;

	/* Invalid code, return -EAGAIN */
	if (code > TSADCV2_DATA_MASK)
		return -EAGAIN;

	while (low <= high && mid) {
		if (code >= v2_code_table[mid].code &&
		    code < v2_code_table[mid - 1].code)
			break;
		else if (code < v2_code_table[mid].code)
			low = mid + 1;
		else
			high = mid - 1;
		mid = (low + high) / 2;
	}

	/*
	 * The 5C granularity provided by the table is too much. Let's
	 * assume that the relationship between sensor readings and
	 * temperature between 2 table entries is linear and interpolate
	 * to produce less granular result.
	 */
	num = v2_code_table[mid].temp - v2_code_table[mid - 1].temp;
	num *= v2_code_table[mid - 1].code - code;
	denom = v2_code_table[mid - 1].code - v2_code_table[mid].code;
	return v2_code_table[mid - 1].temp + (num / denom);
}

/**
 * rk_tsadcv2_initialize - initialize TASDC Controller
 * (1) Set TSADCV2_AUTO_PERIOD, configure the interleave between
 * every two accessing of TSADC in normal operation.
 * (2) Set TSADCV2_AUTO_PERIOD_HT, configure the interleave between
 * every two accessing of TSADC after the temperature is higher
 * than COM_SHUT or COM_INT.
 * (3) Set TSADCV2_HIGH_INT_DEBOUNCE and TSADC_HIGHT_TSHUT_DEBOUNCE,
 * if the temperature is higher than COMP_INT or COMP_SHUT for
 * "debounce" times, TSADC controller will generate interrupt or TSHUT.
 */
static void rk_tsadcv2_initialize(void __iomem *regs,
				  enum tshut_polarity tshut_polarity)
{
	if (tshut_polarity == TSHUT_HIGH_ACTIVE)
		writel_relaxed(0 | (TSADCV2_AUTO_TSHUT_POLARITY_HIGH),
			       regs + TSADCV2_AUTO_CON);
	else
		writel_relaxed(0 | (TSADCV2_AUTO_TSHUT_POLARITY_LOW),
			       regs + TSADCV2_AUTO_CON);

	writel_relaxed(TSADCV2_AUTO_PERIOD_TIME, regs + TSADCV2_AUTO_PERIOD);
	writel_relaxed(TSADCV2_HIGHT_INT_DEBOUNCE_COUNT,
		       regs + TSADCV2_HIGHT_INT_DEBOUNCE);
	writel_relaxed(TSADCV2_AUTO_PERIOD_HT_TIME,
		       regs + TSADCV2_AUTO_PERIOD_HT);
	writel_relaxed(TSADCV2_HIGHT_TSHUT_DEBOUNCE_COUNT,
		       regs + TSADCV2_HIGHT_TSHUT_DEBOUNCE);
}

static void rk_tsadcv2_irq_ack(void __iomem *regs)
{
	u32 val;

	val = readl_relaxed(regs + TSADCV2_INT_PD);
	writel_relaxed(val & TSADCV2_INT_PD_CLEAR, regs + TSADCV2_INT_PD);
}

static void rk_tsadcv2_control(void __iomem *regs, bool enable)
{
	u32 val;

	val = readl_relaxed(regs + TSADCV2_AUTO_CON);
	if (enable)
		val |= TSADCV2_AUTO_EN;
	else
		val &= ~TSADCV2_AUTO_EN;

	writel_relaxed(val, regs + TSADCV2_AUTO_CON);
}

static int rk_tsadcv2_get_temp(int chn, void __iomem *regs, int *temp)
{
	u32 val;

	/* the A/D value of the channel last conversion need some time */
	val = readl_relaxed(regs + TSADCV2_DATA(chn));
	if (val == 0)
		return -EAGAIN;

	*temp = rk_tsadcv2_code_to_temp(val);

	return 0;
}

static void rk_tsadcv2_tshut_temp(int chn, void __iomem *regs, long temp)
{
	u32 tshut_value, val;

	tshut_value = rk_tsadcv2_temp_to_code(temp);
	writel_relaxed(tshut_value, regs + TSADCV2_COMP_SHUT(chn));

	/* TSHUT will be valid */
	val = readl_relaxed(regs + TSADCV2_AUTO_CON);
	writel_relaxed(val | TSADCV2_AUTO_SRC_EN(chn), regs + TSADCV2_AUTO_CON);
}

static void rk_tsadcv2_tshut_mode(int chn, void __iomem *regs,
				  enum tshut_mode mode)
{
	u32 val;

	val = readl_relaxed(regs + TSADCV2_INT_EN);
	if (mode == TSHUT_MODE_GPIO) {
		val &= ~TSADCV2_SHUT_2CRU_SRC_EN(chn);
		val |= TSADCV2_SHUT_2GPIO_SRC_EN(chn);
	} else {
		val &= ~TSADCV2_SHUT_2GPIO_SRC_EN(chn);
		val |= TSADCV2_SHUT_2CRU_SRC_EN(chn);
	}

	writel_relaxed(val, regs + TSADCV2_INT_EN);
}

static const struct rockchip_tsadc_chip rk3288_tsadc_data = {
	.tshut_mode = TSHUT_MODE_GPIO, /* default TSHUT via GPIO give PMIC */
	.tshut_polarity = TSHUT_LOW_ACTIVE, /* default TSHUT LOW ACTIVE */
	.tshut_temp = 95000,

	.initialize = rk_tsadcv2_initialize,
	.irq_ack = rk_tsadcv2_irq_ack,
	.control = rk_tsadcv2_control,
	.get_temp = rk_tsadcv2_get_temp,
	.set_tshut_temp = rk_tsadcv2_tshut_temp,
	.set_tshut_mode = rk_tsadcv2_tshut_mode,
};

static const struct of_device_id of_rockchip_thermal_match[] = {
	{
		.compatible = "rockchip,rk3288-tsadc",
		.data = (void *)&rk3288_tsadc_data,
	},
	{ /* end */ },
};
MODULE_DEVICE_TABLE(of, of_rockchip_thermal_match);

static void
rockchip_thermal_toggle_sensor(struct rockchip_thermal_sensor *sensor, bool on)
{
	struct thermal_zone_device *tzd = sensor->tzd;

	tzd->ops->set_mode(tzd,
		on ? THERMAL_DEVICE_ENABLED : THERMAL_DEVICE_DISABLED);
}

static irqreturn_t rockchip_thermal_alarm_irq_thread(int irq, void *dev)
{
	struct rockchip_thermal_data *thermal = dev;
	int i;

	dev_dbg(&thermal->pdev->dev, "thermal alarm\n");

	thermal->chip->irq_ack(thermal->regs);

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++)
		thermal_zone_device_update(thermal->sensors[i].tzd);

	return IRQ_HANDLED;
}

static int rockchip_thermal_get_temp(void *_sensor, int *out_temp)
{
	struct rockchip_thermal_sensor *sensor = _sensor;
	struct rockchip_thermal_data *thermal = sensor->thermal;
	const struct rockchip_tsadc_chip *tsadc = sensor->thermal->chip;
	int retval;

	retval = tsadc->get_temp(sensor->id, thermal->regs, out_temp);
	dev_dbg(&thermal->pdev->dev, "sensor %d - temp: %d, retval: %d\n",
		sensor->id, *out_temp, retval);

	return retval;
}

static const struct thermal_zone_of_device_ops rockchip_of_thermal_ops = {
	.get_temp = rockchip_thermal_get_temp,
};

static int rockchip_configure_from_dt(struct device *dev,
				      struct device_node *np,
				      struct rockchip_thermal_data *thermal)
{
	u32 shut_temp, tshut_mode, tshut_polarity;

	if (of_property_read_u32(np, "rockchip,hw-tshut-temp", &shut_temp)) {
		dev_warn(dev,
			 "Missing tshut temp property, using default %ld\n",
			 thermal->chip->tshut_temp);
		thermal->tshut_temp = thermal->chip->tshut_temp;
	} else {
		thermal->tshut_temp = shut_temp;
	}

	if (thermal->tshut_temp > INT_MAX) {
		dev_err(dev, "Invalid tshut temperature specified: %ld\n",
			thermal->tshut_temp);
		return -ERANGE;
	}

	if (of_property_read_u32(np, "rockchip,hw-tshut-mode", &tshut_mode)) {
		dev_warn(dev,
			 "Missing tshut mode property, using default (%s)\n",
			 thermal->chip->tshut_mode == TSHUT_MODE_GPIO ?
				"gpio" : "cru");
		thermal->tshut_mode = thermal->chip->tshut_mode;
	} else {
		thermal->tshut_mode = tshut_mode;
	}

	if (thermal->tshut_mode > 1) {
		dev_err(dev, "Invalid tshut mode specified: %d\n",
			thermal->tshut_mode);
		return -EINVAL;
	}

	if (of_property_read_u32(np, "rockchip,hw-tshut-polarity",
				 &tshut_polarity)) {
		dev_warn(dev,
			 "Missing tshut-polarity property, using default (%s)\n",
			 thermal->chip->tshut_polarity == TSHUT_LOW_ACTIVE ?
				"low" : "high");
		thermal->tshut_polarity = thermal->chip->tshut_polarity;
	} else {
		thermal->tshut_polarity = tshut_polarity;
	}

	if (thermal->tshut_polarity > 1) {
		dev_err(dev, "Invalid tshut-polarity specified: %d\n",
			thermal->tshut_polarity);
		return -EINVAL;
	}

	return 0;
}

static int
rockchip_thermal_register_sensor(struct platform_device *pdev,
				 struct rockchip_thermal_data *thermal,
				 struct rockchip_thermal_sensor *sensor,
				 enum sensor_id id)
{
	const struct rockchip_tsadc_chip *tsadc = thermal->chip;
	int error;

	tsadc->set_tshut_mode(id, thermal->regs, thermal->tshut_mode);
	tsadc->set_tshut_temp(id, thermal->regs, thermal->tshut_temp);

	sensor->thermal = thermal;
	sensor->id = id;
	sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev, id, sensor,
						      &rockchip_of_thermal_ops);
	if (IS_ERR(sensor->tzd)) {
		error = PTR_ERR(sensor->tzd);
		dev_err(&pdev->dev, "failed to register sensor %d: %d\n",
			id, error);
		return error;
	}

	return 0;
}

/*
 * Reset TSADC Controller, reset all tsadc registers.
 */
static void rockchip_thermal_reset_controller(struct reset_control *reset)
{
	reset_control_assert(reset);
	usleep_range(10, 20);
	reset_control_deassert(reset);
}

static int rockchip_thermal_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct rockchip_thermal_data *thermal;
	const struct of_device_id *match;
	struct resource *res;
	int irq;
	int i;
	int error;

	match = of_match_node(of_rockchip_thermal_match, np);
	if (!match)
		return -ENXIO;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no irq resource?\n");
		return -EINVAL;
	}

	thermal = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_thermal_data),
			       GFP_KERNEL);
	if (!thermal)
		return -ENOMEM;

	thermal->pdev = pdev;

	thermal->chip = (const struct rockchip_tsadc_chip *)match->data;
	if (!thermal->chip)
		return -EINVAL;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	thermal->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(thermal->regs))
		return PTR_ERR(thermal->regs);

	thermal->reset = devm_reset_control_get(&pdev->dev, "tsadc-apb");
	if (IS_ERR(thermal->reset)) {
		error = PTR_ERR(thermal->reset);
		dev_err(&pdev->dev, "failed to get tsadc reset: %d\n", error);
		return error;
	}

	thermal->clk = devm_clk_get(&pdev->dev, "tsadc");
	if (IS_ERR(thermal->clk)) {
		error = PTR_ERR(thermal->clk);
		dev_err(&pdev->dev, "failed to get tsadc clock: %d\n", error);
		return error;
	}

	thermal->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(thermal->pclk)) {
		error = PTR_ERR(thermal->pclk);
		dev_err(&pdev->dev, "failed to get apb_pclk clock: %d\n",
			error);
		return error;
	}

	error = clk_prepare_enable(thermal->clk);
	if (error) {
		dev_err(&pdev->dev, "failed to enable converter clock: %d\n",
			error);
		return error;
	}

	error = clk_prepare_enable(thermal->pclk);
	if (error) {
		dev_err(&pdev->dev, "failed to enable pclk: %d\n", error);
		goto err_disable_clk;
	}

	rockchip_thermal_reset_controller(thermal->reset);

	error = rockchip_configure_from_dt(&pdev->dev, np, thermal);
	if (error) {
		dev_err(&pdev->dev, "failed to parse device tree data: %d\n",
			error);
		goto err_disable_pclk;
	}

	thermal->chip->initialize(thermal->regs, thermal->tshut_polarity);

	error = rockchip_thermal_register_sensor(pdev, thermal,
						 &thermal->sensors[0],
						 SENSOR_CPU);
	if (error) {
		dev_err(&pdev->dev,
			"failed to register CPU thermal sensor: %d\n", error);
		goto err_disable_pclk;
	}

	error = rockchip_thermal_register_sensor(pdev, thermal,
						 &thermal->sensors[1],
						 SENSOR_GPU);
	if (error) {
		dev_err(&pdev->dev,
			"failed to register GPU thermal sensor: %d\n", error);
		goto err_unregister_cpu_sensor;
	}

	error = devm_request_threaded_irq(&pdev->dev, irq, NULL,
					  &rockchip_thermal_alarm_irq_thread,
					  IRQF_ONESHOT,
					  "rockchip_thermal", thermal);
	if (error) {
		dev_err(&pdev->dev,
			"failed to request tsadc irq: %d\n", error);
		goto err_unregister_gpu_sensor;
	}

	thermal->chip->control(thermal->regs, true);

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++)
		rockchip_thermal_toggle_sensor(&thermal->sensors[i], true);

	platform_set_drvdata(pdev, thermal);

	return 0;

err_unregister_gpu_sensor:
	thermal_zone_of_sensor_unregister(&pdev->dev, thermal->sensors[1].tzd);
err_unregister_cpu_sensor:
	thermal_zone_of_sensor_unregister(&pdev->dev, thermal->sensors[0].tzd);
err_disable_pclk:
	clk_disable_unprepare(thermal->pclk);
err_disable_clk:
	clk_disable_unprepare(thermal->clk);

	return error;
}

static int rockchip_thermal_remove(struct platform_device *pdev)
{
	struct rockchip_thermal_data *thermal = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++) {
		struct rockchip_thermal_sensor *sensor = &thermal->sensors[i];

		rockchip_thermal_toggle_sensor(sensor, false);
		thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
	}

	thermal->chip->control(thermal->regs, false);

	clk_disable_unprepare(thermal->pclk);
	clk_disable_unprepare(thermal->clk);

	return 0;
}

static int __maybe_unused rockchip_thermal_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rockchip_thermal_data *thermal = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++)
		rockchip_thermal_toggle_sensor(&thermal->sensors[i], false);

	thermal->chip->control(thermal->regs, false);

	clk_disable(thermal->pclk);
	clk_disable(thermal->clk);

	return 0;
}

static int __maybe_unused rockchip_thermal_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rockchip_thermal_data *thermal = platform_get_drvdata(pdev);
	int i;
	int error;

	error = clk_enable(thermal->clk);
	if (error)
		return error;

	error = clk_enable(thermal->pclk);
	if (error)
		return error;

	rockchip_thermal_reset_controller(thermal->reset);

	thermal->chip->initialize(thermal->regs, thermal->tshut_polarity);

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++) {
		enum sensor_id id = thermal->sensors[i].id;

		thermal->chip->set_tshut_mode(id, thermal->regs,
					      thermal->tshut_mode);
		thermal->chip->set_tshut_temp(id, thermal->regs,
					      thermal->tshut_temp);
	}

	thermal->chip->control(thermal->regs, true);

	for (i = 0; i < ARRAY_SIZE(thermal->sensors); i++)
		rockchip_thermal_toggle_sensor(&thermal->sensors[i], true);

	return 0;
}

static SIMPLE_DEV_PM_OPS(rockchip_thermal_pm_ops,
			 rockchip_thermal_suspend, rockchip_thermal_resume);

static struct platform_driver rockchip_thermal_driver = {
	.driver = {
		.name = "rockchip-thermal",
		.pm = &rockchip_thermal_pm_ops,
		.of_match_table = of_rockchip_thermal_match,
	},
	.probe = rockchip_thermal_probe,
	.remove = rockchip_thermal_remove,
};

module_platform_driver(rockchip_thermal_driver);

MODULE_DESCRIPTION("ROCKCHIP THERMAL Driver");
MODULE_AUTHOR("Rockchip, Inc.");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:rockchip-thermal");