path: root/drivers/thermal/mediatek/lvts_thermal.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2023 MediaTek Inc.
 * Author: Balsam CHIHI <bchihi@baylibre.com>
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/debugfs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/nvmem-consumer.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/thermal.h>
#include <dt-bindings/thermal/mediatek,lvts-thermal.h>

#define LVTS_MONCTL0(__base)	(__base + 0x0000)
#define LVTS_MONCTL1(__base)	(__base + 0x0004)
#define LVTS_MONCTL2(__base)	(__base + 0x0008)
#define LVTS_MONINT(__base)		(__base + 0x000C)
#define LVTS_MONINTSTS(__base)	(__base + 0x0010)
#define LVTS_MONIDET0(__base)	(__base + 0x0014)
#define LVTS_MONIDET1(__base)	(__base + 0x0018)
#define LVTS_MONIDET2(__base)	(__base + 0x001C)
#define LVTS_MONIDET3(__base)	(__base + 0x0020)
#define LVTS_H2NTHRE(__base)	(__base + 0x0024)
#define LVTS_HTHRE(__base)		(__base + 0x0028)
#define LVTS_OFFSETH(__base)	(__base + 0x0030)
#define LVTS_OFFSETL(__base)	(__base + 0x0034)
#define LVTS_MSRCTL0(__base)	(__base + 0x0038)
#define LVTS_MSRCTL1(__base)	(__base + 0x003C)
#define LVTS_TSSEL(__base)		(__base + 0x0040)
#define LVTS_CALSCALE(__base)	(__base + 0x0048)
#define LVTS_ID(__base)			(__base + 0x004C)
#define LVTS_CONFIG(__base)		(__base + 0x0050)
#define LVTS_EDATA00(__base)	(__base + 0x0054)
#define LVTS_EDATA01(__base)	(__base + 0x0058)
#define LVTS_EDATA02(__base)	(__base + 0x005C)
#define LVTS_EDATA03(__base)	(__base + 0x0060)
#define LVTS_MSR0(__base)		(__base + 0x0090)
#define LVTS_MSR1(__base)		(__base + 0x0094)
#define LVTS_MSR2(__base)		(__base + 0x0098)
#define LVTS_MSR3(__base)		(__base + 0x009C)
#define LVTS_IMMD0(__base)		(__base + 0x00A0)
#define LVTS_IMMD1(__base)		(__base + 0x00A4)
#define LVTS_IMMD2(__base)		(__base + 0x00A8)
#define LVTS_IMMD3(__base)		(__base + 0x00AC)
#define LVTS_PROTCTL(__base)	(__base + 0x00C0)
#define LVTS_PROTTA(__base)		(__base + 0x00C4)
#define LVTS_PROTTB(__base)		(__base + 0x00C8)
#define LVTS_PROTTC(__base)		(__base + 0x00CC)
#define LVTS_CLKEN(__base)		(__base + 0x00E4)

#define LVTS_PERIOD_UNIT			((118 * 1000) / (256 * 38))
#define LVTS_GROUP_INTERVAL			1
#define LVTS_FILTER_INTERVAL		1
#define LVTS_SENSOR_INTERVAL		1
#define LVTS_HW_FILTER				0x2
#define LVTS_TSSEL_CONF				0x13121110
#define LVTS_CALSCALE_CONF			0x300
#define LVTS_MONINT_CONF			0x9FBF7BDE

#define LVTS_INT_SENSOR0			0x0009001F
#define LVTS_INT_SENSOR1			0X000881F0
#define LVTS_INT_SENSOR2			0x00247C00
#define LVTS_INT_SENSOR3			0x1FC00000

#define LVTS_SENSOR_MAX				4
#define LVTS_GOLDEN_TEMP_MAX		62
#define LVTS_GOLDEN_TEMP_DEFAULT	50
#define LVTS_COEFF_A				-250460
#define LVTS_COEFF_B				250460

#define LVTS_MSR_IMMEDIATE_MODE		0
#define LVTS_MSR_FILTERED_MODE		1

#define LVTS_HW_SHUTDOWN_MT8195		105000

static int golden_temp = LVTS_GOLDEN_TEMP_DEFAULT;
static int coeff_b = LVTS_COEFF_B;

struct lvts_sensor_data {
	int dt_id;
};

struct lvts_ctrl_data {
	struct lvts_sensor_data lvts_sensor[LVTS_SENSOR_MAX];
	int cal_offset[LVTS_SENSOR_MAX];
	int hw_tshut_temp;
	int num_lvts_sensor;
	int offset;
	int mode;
};

struct lvts_data {
	const struct lvts_ctrl_data *lvts_ctrl;
	int num_lvts_ctrl;
};

struct lvts_sensor {
	struct thermal_zone_device *tz;
	void __iomem *msr;
	void __iomem *base;
	int id;
	int dt_id;
};

struct lvts_ctrl {
	struct lvts_sensor sensors[LVTS_SENSOR_MAX];
	u32 calibration[LVTS_SENSOR_MAX];
	u32 hw_tshut_raw_temp;
	int num_lvts_sensor;
	int mode;
	void __iomem *base;
};

struct lvts_domain {
	struct lvts_ctrl *lvts_ctrl;
	struct reset_control *reset;
	struct clk *clk;
	int num_lvts_ctrl;
	void __iomem *base;
	size_t calib_len;
	u8 *calib;
#ifdef CONFIG_DEBUG_FS
	struct dentry *dom_dentry;
#endif
};

#ifdef CONFIG_MTK_LVTS_THERMAL_DEBUGFS

#define LVTS_DEBUG_FS_REGS(__reg)		\
{						\
	.name = __stringify(__reg),		\
	.offset = __reg(0),			\
}

static const struct debugfs_reg32 lvts_regs[] = {
	LVTS_DEBUG_FS_REGS(LVTS_MONCTL0),
	LVTS_DEBUG_FS_REGS(LVTS_MONCTL1),
	LVTS_DEBUG_FS_REGS(LVTS_MONCTL2),
	LVTS_DEBUG_FS_REGS(LVTS_MONINT),
	LVTS_DEBUG_FS_REGS(LVTS_MONINTSTS),
	LVTS_DEBUG_FS_REGS(LVTS_MONIDET0),
	LVTS_DEBUG_FS_REGS(LVTS_MONIDET1),
	LVTS_DEBUG_FS_REGS(LVTS_MONIDET2),
	LVTS_DEBUG_FS_REGS(LVTS_MONIDET3),
	LVTS_DEBUG_FS_REGS(LVTS_H2NTHRE),
	LVTS_DEBUG_FS_REGS(LVTS_HTHRE),
	LVTS_DEBUG_FS_REGS(LVTS_OFFSETH),
	LVTS_DEBUG_FS_REGS(LVTS_OFFSETL),
	LVTS_DEBUG_FS_REGS(LVTS_MSRCTL0),
	LVTS_DEBUG_FS_REGS(LVTS_MSRCTL1),
	LVTS_DEBUG_FS_REGS(LVTS_TSSEL),
	LVTS_DEBUG_FS_REGS(LVTS_CALSCALE),
	LVTS_DEBUG_FS_REGS(LVTS_ID),
	LVTS_DEBUG_FS_REGS(LVTS_CONFIG),
	LVTS_DEBUG_FS_REGS(LVTS_EDATA00),
	LVTS_DEBUG_FS_REGS(LVTS_EDATA01),
	LVTS_DEBUG_FS_REGS(LVTS_EDATA02),
	LVTS_DEBUG_FS_REGS(LVTS_EDATA03),
	LVTS_DEBUG_FS_REGS(LVTS_MSR0),
	LVTS_DEBUG_FS_REGS(LVTS_MSR1),
	LVTS_DEBUG_FS_REGS(LVTS_MSR2),
	LVTS_DEBUG_FS_REGS(LVTS_MSR3),
	LVTS_DEBUG_FS_REGS(LVTS_IMMD0),
	LVTS_DEBUG_FS_REGS(LVTS_IMMD1),
	LVTS_DEBUG_FS_REGS(LVTS_IMMD2),
	LVTS_DEBUG_FS_REGS(LVTS_IMMD3),
	LVTS_DEBUG_FS_REGS(LVTS_PROTCTL),
	LVTS_DEBUG_FS_REGS(LVTS_PROTTA),
	LVTS_DEBUG_FS_REGS(LVTS_PROTTB),
	LVTS_DEBUG_FS_REGS(LVTS_PROTTC),
	LVTS_DEBUG_FS_REGS(LVTS_CLKEN),
};

static int lvts_debugfs_init(struct device *dev, struct lvts_domain *lvts_td)
{
	struct debugfs_regset32 *regset;
	struct lvts_ctrl *lvts_ctrl;
	struct dentry *dentry;
	char name[64];
	int i;

	lvts_td->dom_dentry = debugfs_create_dir(dev_name(dev), NULL);
	if (!lvts_td->dom_dentry)
		return 0;

	for (i = 0; i < lvts_td->num_lvts_ctrl; i++) {

		lvts_ctrl = &lvts_td->lvts_ctrl[i];

		sprintf(name, "controller%d", i);
		dentry = debugfs_create_dir(name, lvts_td->dom_dentry);
		if (!dentry)
			continue;

		regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL);
		if (!regset)
			continue;

		regset->base = lvts_ctrl->base;
		regset->regs = lvts_regs;
		regset->nregs = ARRAY_SIZE(lvts_regs);

		debugfs_create_regset32("registers", 0400, dentry, regset);
	}

	return 0;
}

static void lvts_debugfs_exit(struct lvts_domain *lvts_td)
{
	debugfs_remove_recursive(lvts_td->dom_dentry);
}

#else

static inline int lvts_debugfs_init(struct device *dev,
				    struct lvts_domain *lvts_td)
{
	return 0;
}

static void lvts_debugfs_exit(struct lvts_domain *lvts_td) { }

#endif

static int lvts_raw_to_temp(u32 raw_temp)
{
	int temperature;

	temperature = ((s64)(raw_temp & 0xFFFF) * LVTS_COEFF_A) >> 14;
	temperature += coeff_b;

	return temperature;
}

static u32 lvts_temp_to_raw(int temperature)
{
	u32 raw_temp = ((s64)(coeff_b - temperature)) << 14;

	raw_temp = div_s64(raw_temp, -LVTS_COEFF_A);

	return raw_temp;
}

static int lvts_get_temp(struct thermal_zone_device *tz, int *temp)
{
	struct lvts_sensor *lvts_sensor = tz->devdata;
	void __iomem *msr = lvts_sensor->msr;
	u32 value;

	/*
	 * Measurement registers:
	 *
	 * LVTS_MSR[0-3] / LVTS_IMMD[0-3]
	 *
	 * Bits:
	 *
	 * 32-17: Unused
	 * 16	: Valid temperature
	 * 15-0	: Raw temperature
	 */
	value = readl(msr);

	/*
	 * As the thermal zone temperature will read before the
	 * hardware sensor is fully initialized, we have to check the
	 * validity of the temperature returned when reading the
	 * measurement register. The thermal controller will set the
	 * valid bit temperature only when it is totally initialized.
	 *
	 * Otherwise, we may end up with garbage values out of the
	 * functionning temperature and directly jump to a system
	 * shutdown.
	 */
	if (!(value & BIT(16)))
		return -EAGAIN;

	*temp = lvts_raw_to_temp(value & 0xFFFF);

	return 0;
}

static int lvts_set_trips(struct thermal_zone_device *tz, int low, int high)
{
	struct lvts_sensor *lvts_sensor = tz->devdata;
	void __iomem *base = lvts_sensor->base;
	u32 raw_low = lvts_temp_to_raw(low);
	u32 raw_high = lvts_temp_to_raw(high);

	/*
	 * Hot to normal temperature threshold
	 *
	 * LVTS_H2NTHRE
	 *
	 * Bits:
	 *
	 * 14-0 : Raw temperature for threshold
	 */
	if (low != -INT_MAX) {
		dev_dbg(&tz->device, "Setting low limit temperature interrupt: %d\n", low);
		writel(raw_low, LVTS_H2NTHRE(base));
	}

	/*
	 * Hot temperature threshold
	 *
	 * LVTS_HTHRE
	 *
	 * Bits:
	 *
	 * 14-0 : Raw temperature for threshold
	 */
	dev_dbg(&tz->device, "Setting high limit temperature interrupt: %d\n", high);
	writel(raw_high, LVTS_HTHRE(base));

	return 0;
}

static irqreturn_t lvts_ctrl_irq_handler(struct lvts_ctrl *lvts_ctrl)
{
	irqreturn_t iret = IRQ_NONE;
	u32 value;
	u32 masks[] = {
		LVTS_INT_SENSOR0,
		LVTS_INT_SENSOR1,
		LVTS_INT_SENSOR2,
		LVTS_INT_SENSOR3
	};
	int i;

	/*
	 * Interrupt monitoring status
	 *
	 * LVTS_MONINTST
	 *
	 * Bits:
	 *
	 * 31 : Interrupt for stage 3
	 * 30 : Interrupt for stage 2
	 * 29 : Interrupt for state 1
	 * 28 : Interrupt using filter on sensor 3
	 *
	 * 27 : Interrupt using immediate on sensor 3
	 * 26 : Interrupt normal to hot on sensor 3
	 * 25 : Interrupt high offset on sensor 3
	 * 24 : Interrupt low offset on sensor 3
	 *
	 * 23 : Interrupt hot threshold on sensor 3
	 * 22 : Interrupt cold threshold on sensor 3
	 * 21 : Interrupt using filter on sensor 2
	 * 20 : Interrupt using filter on sensor 1
	 *
	 * 19 : Interrupt using filter on sensor 0
	 * 18 : Interrupt using immediate on sensor 2
	 * 17 : Interrupt using immediate on sensor 1
	 * 16 : Interrupt using immediate on sensor 0
	 *
	 * 15 : Interrupt device access timeout interrupt
	 * 14 : Interrupt normal to hot on sensor 2
	 * 13 : Interrupt high offset interrupt on sensor 2
	 * 12 : Interrupt low offset interrupt on sensor 2
	 *
	 * 11 : Interrupt hot threshold on sensor 2
	 * 10 : Interrupt cold threshold on sensor 2
	 *  9 : Interrupt normal to hot on sensor 1
	 *  8 : Interrupt high offset interrupt on sensor 1
	 *
	 *  7 : Interrupt low offset interrupt on sensor 1
	 *  6 : Interrupt hot threshold on sensor 1
	 *  5 : Interrupt cold threshold on sensor 1
	 *  4 : Interrupt normal to hot on sensor 0
	 *
	 *  3 : Interrupt high offset interrupt on sensor 0
	 *  2 : Interrupt low offset interrupt on sensor 0
	 *  1 : Interrupt hot threshold on sensor 0
	 *  0 : Interrupt cold threshold on sensor 0
	 *
	 * We are interested in the sensor(s) responsible of the
	 * interrupt event. We update the thermal framework with the
	 * thermal zone associated with the sensor. The framework will
	 * take care of the rest whatever the kind of interrupt, we
	 * are only interested in which sensor raised the interrupt.
	 *
	 * sensor 3 interrupt: 0001 1111 1100 0000 0000 0000 0000 0000
	 *                  => 0x1FC00000
	 * sensor 2 interrupt: 0000 0000 0010 0100 0111 1100 0000 0000
	 *                  => 0x00247C00
	 * sensor 1 interrupt: 0000 0000 0001 0001 0000 0011 1110 0000
	 *                  => 0X000881F0
	 * sensor 0 interrupt: 0000 0000 0000 1001 0000 0000 0001 1111
	 *                  => 0x0009001F
	 */
	value = readl(LVTS_MONINTSTS(lvts_ctrl->base));

	/*
	 * Let's figure out which sensors raised the interrupt
	 *
	 * NOTE: the masks array must be ordered with the index
	 * corresponding to the sensor id eg. index=0, mask for
	 * sensor0.
	 */
	for (i = 0; i < ARRAY_SIZE(masks); i++) {

		if (!(value & masks[i]))
			continue;

		thermal_zone_device_update(lvts_ctrl->sensors[i].tz,
					   THERMAL_TRIP_VIOLATED);
		iret = IRQ_HANDLED;
	}

	/*
	 * Write back to clear the interrupt status (W1C)
	 */
	writel(value, LVTS_MONINTSTS(lvts_ctrl->base));

	return iret;
}

/*
 * Temperature interrupt handler. Even if the driver supports more
 * interrupt modes, we use the interrupt when the temperature crosses
 * the hot threshold the way up and the way down (modulo the
 * hysteresis).
 *
 * Each thermal domain has a couple of interrupts, one for hardware
 * reset and another one for all the thermal events happening on the
 * different sensors.
 *
 * The interrupt is configured for thermal events when crossing the
 * hot temperature limit. At each interrupt, we check in every
 * controller if there is an interrupt pending.
 */
static irqreturn_t lvts_irq_handler(int irq, void *data)
{
	struct lvts_domain *lvts_td = data;
	irqreturn_t aux, iret = IRQ_NONE;
	int i;

	for (i = 0; i < lvts_td->num_lvts_ctrl; i++) {

		aux = lvts_ctrl_irq_handler(lvts_td->lvts_ctrl);
		if (aux != IRQ_HANDLED)
			continue;

		iret = IRQ_HANDLED;
	}

	return iret;
}

static struct thermal_zone_device_ops lvts_ops = {
	.get_temp = lvts_get_temp,
	.set_trips = lvts_set_trips,
};

static int lvts_sensor_init(struct device *dev, struct lvts_ctrl *lvts_ctrl,
					const struct lvts_ctrl_data *lvts_ctrl_data)
{
	struct lvts_sensor *lvts_sensor = lvts_ctrl->sensors;
	void __iomem *msr_regs[] = {
		LVTS_MSR0(lvts_ctrl->base),
		LVTS_MSR1(lvts_ctrl->base),
		LVTS_MSR2(lvts_ctrl->base),
		LVTS_MSR3(lvts_ctrl->base)
	};

	void __iomem *imm_regs[] = {
		LVTS_IMMD0(lvts_ctrl->base),
		LVTS_IMMD1(lvts_ctrl->base),
		LVTS_IMMD2(lvts_ctrl->base),
		LVTS_IMMD3(lvts_ctrl->base)
	};

	int i;

	for (i = 0; i < lvts_ctrl_data->num_lvts_sensor; i++) {

		int dt_id = lvts_ctrl_data->lvts_sensor[i].dt_id;

		/*
		 * At this point, we don't know which id matches which
		 * sensor. Let's set arbitrally the id from the index.
		 */
		lvts_sensor[i].id = i;

		/*
		 * The thermal zone registration will set the trip
		 * point interrupt in the thermal controller
		 * register. But this one will be reset in the
		 * initialization after. So we need to post pone the
		 * thermal zone creation after the controller is
		 * setup. For this reason, we store the device tree
		 * node id from the data in the sensor structure
		 */
		lvts_sensor[i].dt_id = dt_id;

		/*
		 * We assign the base address of the thermal
		 * controller as a back pointer. So it will be
		 * accessible from the different thermal framework ops
		 * as we pass the lvts_sensor pointer as thermal zone
		 * private data.
		 */
		lvts_sensor[i].base = lvts_ctrl->base;

		/*
		 * Each sensor has its own register address to read from.
		 */
		lvts_sensor[i].msr = lvts_ctrl_data->mode == LVTS_MSR_IMMEDIATE_MODE ?
			imm_regs[i] : msr_regs[i];
	};

	lvts_ctrl->num_lvts_sensor = lvts_ctrl_data->num_lvts_sensor;

	return 0;
}

/*
 * The efuse blob values follows the sensor enumeration per thermal
 * controller. The decoding of the stream is as follow:
 *
 *                        <--?-> <----big0 ???---> <-sensor0-> <-0->
 *                        ------------------------------------------
 * index in the stream: : | 0x0 | 0x1 | 0x2 | 0x3 | 0x4 | 0x5 | 0x6 |
 *                        ------------------------------------------
 *
 *                        <--sensor1--><-0-> <----big1 ???---> <-sen
 *                        ------------------------------------------
 *                        | 0x7 | 0x8 | 0x9 | 0xA | 0xB | OxC | OxD |
 *                        ------------------------------------------
 *
 *                        sor0-> <-0-> <-sensor1-> <-0-> ..........
 *                        ------------------------------------------
 *                        | 0x7 | 0x8 | 0x9 | 0xA | 0xB | OxC | OxD |
 *                        ------------------------------------------
 *
 * And so on ...
 *
 * The data description gives the offset of the calibration data in
 * this bytes stream for each sensor.
 *
 * Each thermal controller can handle up to 4 sensors max, we don't
 * care if there are less as the array of calibration is sized to 4
 * anyway. The unused sensor slot will be zeroed.
 */
static int lvts_calibration_init(struct device *dev, struct lvts_ctrl *lvts_ctrl,
					const struct lvts_ctrl_data *lvts_ctrl_data,
					u8 *efuse_calibration)
{
	int i;

	for (i = 0; i < lvts_ctrl_data->num_lvts_sensor; i++)
		memcpy(&lvts_ctrl->calibration[i],
		       efuse_calibration + lvts_ctrl_data->cal_offset[i], 2);

	return 0;
}

/*
 * The efuse bytes stream can be split into different chunk of
 * nvmems. This function reads and concatenate those into a single
 * buffer so it can be read sequentially when initializing the
 * calibration data.
 */
static int lvts_calibration_read(struct device *dev, struct lvts_domain *lvts_td,
					const struct lvts_data *lvts_data)
{
	struct device_node *np = dev_of_node(dev);
	struct nvmem_cell *cell;
	struct property *prop;
	const char *cell_name;

	of_property_for_each_string(np, "nvmem-cell-names", prop, cell_name) {
		size_t len;
		u8 *efuse;

		cell = of_nvmem_cell_get(np, cell_name);
		if (IS_ERR(cell)) {
			dev_err(dev, "Failed to get cell '%s'\n", cell_name);
			return PTR_ERR(cell);
		}

		efuse = nvmem_cell_read(cell, &len);

		nvmem_cell_put(cell);

		if (IS_ERR(efuse)) {
			dev_err(dev, "Failed to read cell '%s'\n", cell_name);
			return PTR_ERR(efuse);
		}

		lvts_td->calib = devm_krealloc(dev, lvts_td->calib,
					       lvts_td->calib_len + len, GFP_KERNEL);
		if (!lvts_td->calib)
			return -ENOMEM;

		memcpy(lvts_td->calib + lvts_td->calib_len, efuse, len);

		lvts_td->calib_len += len;

		kfree(efuse);
	}

	return 0;
}

static int lvts_golden_temp_init(struct device *dev, u32 *value)
{
	u32 gt;

	gt = (*value) >> 24;

	if (gt && gt < LVTS_GOLDEN_TEMP_MAX)
		golden_temp = gt;

	coeff_b = golden_temp * 500 + LVTS_COEFF_B;

	return 0;
}

static int lvts_ctrl_init(struct device *dev, struct lvts_domain *lvts_td,
					const struct lvts_data *lvts_data)
{
	size_t size = sizeof(*lvts_td->lvts_ctrl) * lvts_data->num_lvts_ctrl;
	struct lvts_ctrl *lvts_ctrl;
	int i, ret;

	/*
	 * Create the calibration bytes stream from efuse data
	 */
	ret = lvts_calibration_read(dev, lvts_td, lvts_data);
	if (ret)
		return ret;

	/*
	 * The golden temp information is contained in the first chunk
	 * of efuse data.
	 */
	ret = lvts_golden_temp_init(dev, (u32 *)lvts_td->calib);
	if (ret)
		return ret;

	lvts_ctrl = devm_kzalloc(dev, size, GFP_KERNEL);
	if (!lvts_ctrl)
		return -ENOMEM;

	for (i = 0; i < lvts_data->num_lvts_ctrl; i++) {

		lvts_ctrl[i].base = lvts_td->base + lvts_data->lvts_ctrl[i].offset;

		ret = lvts_sensor_init(dev, &lvts_ctrl[i],
				       &lvts_data->lvts_ctrl[i]);
		if (ret)
			return ret;

		ret = lvts_calibration_init(dev, &lvts_ctrl[i],
					    &lvts_data->lvts_ctrl[i],
					    lvts_td->calib);
		if (ret)
			return ret;

		/*
		 * The mode the ctrl will use to read the temperature
		 * (filtered or immediate)
		 */
		lvts_ctrl[i].mode = lvts_data->lvts_ctrl[i].mode;

		/*
		 * The temperature to raw temperature must be done
		 * after initializing the calibration.
		 */
		lvts_ctrl[i].hw_tshut_raw_temp =
			lvts_temp_to_raw(lvts_data->lvts_ctrl[i].hw_tshut_temp);
	}

	/*
	 * We no longer need the efuse bytes stream, let's free it
	 */
	devm_kfree(dev, lvts_td->calib);

	lvts_td->lvts_ctrl = lvts_ctrl;
	lvts_td->num_lvts_ctrl = lvts_data->num_lvts_ctrl;

	return 0;
}

/*
 * At this point the configuration register is the only place in the
 * driver where we write multiple values. Per hardware constraint,
 * each write in the configuration register must be separated by a
 * delay of 2 us.
 */
static void lvts_write_config(struct lvts_ctrl *lvts_ctrl, u32 *cmds, int nr_cmds)
{
	int i;

	/*
	 * Configuration register
	 */
	for (i = 0; i < nr_cmds; i++) {
		writel(cmds[i], LVTS_CONFIG(lvts_ctrl->base));
		usleep_range(2, 4);
	}
}

static int lvts_irq_init(struct lvts_ctrl *lvts_ctrl)
{
	/*
	 * LVTS_PROTCTL : Thermal Protection Sensor Selection
	 *
	 * Bits:
	 *
	 * 19-18 : Sensor to base the protection on
	 * 17-16 : Strategy:
	 *         00 : Average of 4 sensors
	 *         01 : Max of 4 sensors
	 *         10 : Selected sensor with bits 19-18
	 *         11 : Reserved
	 */
	writel(BIT(16), LVTS_PROTCTL(lvts_ctrl->base));

	/*
	 * LVTS_PROTTA : Stage 1 temperature threshold
	 * LVTS_PROTTB : Stage 2 temperature threshold
	 * LVTS_PROTTC : Stage 3 temperature threshold
	 *
	 * Bits:
	 *
	 * 14-0: Raw temperature threshold
	 *
	 * writel(0x0, LVTS_PROTTA(lvts_ctrl->base));
	 * writel(0x0, LVTS_PROTTB(lvts_ctrl->base));
	 */
	writel(lvts_ctrl->hw_tshut_raw_temp, LVTS_PROTTC(lvts_ctrl->base));

	/*
	 * LVTS_MONINT : Interrupt configuration register
	 *
	 * The LVTS_MONINT register layout is the same as the LVTS_MONINTSTS
	 * register, except we set the bits to enable the interrupt.
	 */
	writel(LVTS_MONINT_CONF, LVTS_MONINT(lvts_ctrl->base));

	return 0;
}

static int lvts_domain_reset(struct device *dev, struct reset_control *reset)
{
	int ret;

	ret = reset_control_assert(reset);
	if (ret)
		return ret;

	return reset_control_deassert(reset);
}

/*
 * Enable or disable the clocks of a specified thermal controller
 */
static int lvts_ctrl_set_enable(struct lvts_ctrl *lvts_ctrl, int enable)
{
	/*
	 * LVTS_CLKEN : Internal LVTS clock
	 *
	 * Bits:
	 *
	 * 0 : enable / disable clock
	 */
	writel(enable, LVTS_CLKEN(lvts_ctrl->base));

	return 0;
}

static int lvts_ctrl_connect(struct device *dev, struct lvts_ctrl *lvts_ctrl)
{
	u32 id, cmds[] = { 0xC103FFFF, 0xC502FF55 };

	lvts_write_config(lvts_ctrl, cmds, ARRAY_SIZE(cmds));

	/*
	 * LVTS_ID : Get ID and status of the thermal controller
	 *
	 * Bits:
	 *
	 * 0-5	: thermal controller id
	 *   7	: thermal controller connection is valid
	 */
	id = readl(LVTS_ID(lvts_ctrl->base));
	if (!(id & BIT(7)))
		return -EIO;

	return 0;
}

static int lvts_ctrl_initialize(struct device *dev, struct lvts_ctrl *lvts_ctrl)
{
	/*
	 * Write device mask: 0xC1030000
	 */
	u32 cmds[] = {
		0xC1030E01, 0xC1030CFC, 0xC1030A8C, 0xC103098D, 0xC10308F1,
		0xC10307A6, 0xC10306B8, 0xC1030500, 0xC1030420, 0xC1030300,
		0xC1030030, 0xC10300F6, 0xC1030050, 0xC1030060, 0xC10300AC,
		0xC10300FC, 0xC103009D, 0xC10300F1, 0xC10300E1
	};

	lvts_write_config(lvts_ctrl, cmds, ARRAY_SIZE(cmds));

	return 0;
}

static int lvts_ctrl_calibrate(struct device *dev, struct lvts_ctrl *lvts_ctrl)
{
	int i;
	void __iomem *lvts_edata[] = {
		LVTS_EDATA00(lvts_ctrl->base),
		LVTS_EDATA01(lvts_ctrl->base),
		LVTS_EDATA02(lvts_ctrl->base),
		LVTS_EDATA03(lvts_ctrl->base)
	};

	/*
	 * LVTS_EDATA0X : Efuse calibration reference value for sensor X
	 *
	 * Bits:
	 *
	 * 20-0 : Efuse value for normalization data
	 */
	for (i = 0; i < LVTS_SENSOR_MAX; i++)
		writel(lvts_ctrl->calibration[i], lvts_edata[i]);

	return 0;
}

static int lvts_ctrl_configure(struct device *dev, struct lvts_ctrl *lvts_ctrl)
{
	u32 value;

	/*
	 * LVTS_TSSEL : Sensing point index numbering
	 *
	 * Bits:
	 *
	 * 31-24: ADC Sense 3
	 * 23-16: ADC Sense 2
	 * 15-8	: ADC Sense 1
	 * 7-0	: ADC Sense 0
	 */
	value = LVTS_TSSEL_CONF;
	writel(value, LVTS_TSSEL(lvts_ctrl->base));

	/*
	 * LVTS_CALSCALE : ADC voltage round
	 */
	value = 0x300;
	value = LVTS_CALSCALE_CONF;

	/*
	 * LVTS_MSRCTL0 : Sensor filtering strategy
	 *
	 * Filters:
	 *
	 * 000 : One sample
	 * 001 : Avg 2 samples
	 * 010 : 4 samples, drop min and max, avg 2 samples
	 * 011 : 6 samples, drop min and max, avg 4 samples
	 * 100 : 10 samples, drop min and max, avg 8 samples
	 * 101 : 18 samples, drop min and max, avg 16 samples
	 *
	 * Bits:
	 *
	 * 0-2  : Sensor0 filter
	 * 3-5  : Sensor1 filter
	 * 6-8  : Sensor2 filter
	 * 9-11 : Sensor3 filter
	 */
	value = LVTS_HW_FILTER << 9 |  LVTS_HW_FILTER << 6 |
			LVTS_HW_FILTER << 3 | LVTS_HW_FILTER;
	writel(value, LVTS_MSRCTL0(lvts_ctrl->base));

	/*
	 * LVTS_MSRCTL1 : Measurement control
	 *
	 * Bits:
	 *
	 * 9: Ignore MSRCTL0 config and do immediate measurement on sensor3
	 * 6: Ignore MSRCTL0 config and do immediate measurement on sensor2
	 * 5: Ignore MSRCTL0 config and do immediate measurement on sensor1
	 * 4: Ignore MSRCTL0 config and do immediate measurement on sensor0
	 *
	 * That configuration will ignore the filtering and the delays
	 * introduced below in MONCTL1 and MONCTL2
	 */
	if (lvts_ctrl->mode == LVTS_MSR_IMMEDIATE_MODE) {
		value = BIT(9) | BIT(6) | BIT(5) | BIT(4);
		writel(value, LVTS_MSRCTL1(lvts_ctrl->base));
	}

	/*
	 * LVTS_MONCTL1 : Period unit and group interval configuration
	 *
	 * The clock source of LVTS thermal controller is 26MHz.
	 *
	 * The period unit is a time base for all the interval delays
	 * specified in the registers. By default we use 12. The time
	 * conversion is done by multiplying by 256 and 1/26.10^6
	 *
	 * An interval delay multiplied by the period unit gives the
	 * duration in seconds.
	 *
	 * - Filter interval delay is a delay between two samples of
	 * the same sensor.
	 *
	 * - Sensor interval delay is a delay between two samples of
	 * different sensors.
	 *
	 * - Group interval delay is a delay between different rounds.
	 *
	 * For example:
	 *     If Period unit = C, filter delay = 1, sensor delay = 2, group delay = 1,
	 *     and two sensors, TS1 and TS2, are in a LVTS thermal controller
	 *     and then
	 *     Period unit time = C * 1/26M * 256 = 12 * 38.46ns * 256 = 118.149us
	 *     Filter interval delay = 1 * Period unit = 118.149us
	 *     Sensor interval delay = 2 * Period unit = 236.298us
	 *     Group interval delay = 1 * Period unit = 118.149us
	 *
	 *     TS1    TS1 ... TS1    TS2    TS2 ... TS2    TS1...
	 *        <--> Filter interval delay
	 *                       <--> Sensor interval delay
	 *                                             <--> Group interval delay
	 * Bits:
	 *      29 - 20 : Group interval
	 *      16 - 13 : Send a single interrupt when crossing the hot threshold (1)
	 *                or an interrupt everytime the hot threshold is crossed (0)
	 *       9 - 0  : Period unit
	 *
	 */
	value = LVTS_GROUP_INTERVAL << 20 | LVTS_PERIOD_UNIT;
	writel(value, LVTS_MONCTL1(lvts_ctrl->base));

	/*
	 * LVTS_MONCTL2 : Filtering and sensor interval
	 *
	 * Bits:
	 *
	 *      25-16 : Interval unit in PERIOD_UNIT between sample on
	 *              the same sensor, filter interval
	 *       9-0  : Interval unit in PERIOD_UNIT between each sensor
	 *
	 */
	value = LVTS_FILTER_INTERVAL << 16 | LVTS_SENSOR_INTERVAL;
	writel(value, LVTS_MONCTL2(lvts_ctrl->base));

	return lvts_irq_init(lvts_ctrl);
}

static int lvts_ctrl_start(struct device *dev, struct lvts_ctrl *lvts_ctrl)
{
	struct lvts_sensor *lvts_sensors = lvts_ctrl->sensors;
	struct thermal_zone_device *tz;
	u32 sensor_map = 0;
	int i;

	for (i = 0; i < lvts_ctrl->num_lvts_sensor; i++) {

		int dt_id = lvts_sensors[i].dt_id;

		tz = devm_thermal_of_zone_register(dev, dt_id, &lvts_sensors[i],
						   &lvts_ops);
		if (IS_ERR(tz)) {
			/*
			 * This thermal zone is not described in the
			 * device tree. It is not an error from the
			 * thermal OF code POV, we just continue.
			 */
			if (PTR_ERR(tz) == -ENODEV)
				continue;

			return PTR_ERR(tz);
		}

		/*
		 * The thermal zone pointer will be needed in the
		 * interrupt handler, we store it in the sensor
		 * structure. The thermal domain structure will be
		 * passed to the interrupt handler private data as the
		 * interrupt is shared for all the controller
		 * belonging to the thermal domain.
		 */
		lvts_sensors[i].tz = tz;

		/*
		 * This sensor was correctly associated with a thermal
		 * zone, let's set the corresponding bit in the sensor
		 * map, so we can enable the temperature monitoring in
		 * the hardware thermal controller.
		 */
		sensor_map |= BIT(i);
	}

	/*
	 * Bits:
	 *      9: Single point access flow
	 *    0-3: Enable sensing point 0-3
	 *
	 * The initialization of the thermal zones give us
	 * which sensor point to enable. If any thermal zone
	 * was not described in the device tree, it won't be
	 * enabled here in the sensor map.
	 */
	writel(sensor_map | BIT(9), LVTS_MONCTL0(lvts_ctrl->base));

	return 0;
}

static int lvts_domain_init(struct device *dev, struct lvts_domain *lvts_td,
					const struct lvts_data *lvts_data)
{
	struct lvts_ctrl *lvts_ctrl;
	int i, ret;

	ret = lvts_ctrl_init(dev, lvts_td, lvts_data);
	if (ret)
		return ret;

	ret = lvts_domain_reset(dev, lvts_td->reset);
	if (ret) {
		dev_dbg(dev, "Failed to reset domain");
		return ret;
	}

	for (i = 0; i < lvts_td->num_lvts_ctrl; i++) {

		lvts_ctrl = &lvts_td->lvts_ctrl[i];

		/*
		 * Initialization steps:
		 *
		 * - Enable the clock
		 * - Connect to the LVTS
		 * - Initialize the LVTS
		 * - Prepare the calibration data
		 * - Select monitored sensors
		 * [ Configure sampling ]
		 * [ Configure the interrupt ]
		 * - Start measurement
		 */
		ret = lvts_ctrl_set_enable(lvts_ctrl, true);
		if (ret) {
			dev_dbg(dev, "Failed to enable LVTS clock");
			return ret;
		}

		ret = lvts_ctrl_connect(dev, lvts_ctrl);
		if (ret) {
			dev_dbg(dev, "Failed to connect to LVTS controller");
			return ret;
		}

		ret = lvts_ctrl_initialize(dev, lvts_ctrl);
		if (ret) {
			dev_dbg(dev, "Failed to initialize controller");
			return ret;
		}

		ret = lvts_ctrl_calibrate(dev, lvts_ctrl);
		if (ret) {
			dev_dbg(dev, "Failed to calibrate controller");
			return ret;
		}

		ret = lvts_ctrl_configure(dev, lvts_ctrl);
		if (ret) {
			dev_dbg(dev, "Failed to configure controller");
			return ret;
		}

		ret = lvts_ctrl_start(dev, lvts_ctrl);
		if (ret) {
			dev_dbg(dev, "Failed to start controller");
			return ret;
		}
	}

	return lvts_debugfs_init(dev, lvts_td);
}

static int lvts_probe(struct platform_device *pdev)
{
	const struct lvts_data *lvts_data;
	struct lvts_domain *lvts_td;
	struct device *dev = &pdev->dev;
	struct resource *res;
	int irq, ret;

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

	lvts_data = of_device_get_match_data(dev);

	lvts_td->clk = devm_clk_get_enabled(dev, NULL);
	if (IS_ERR(lvts_td->clk))
		return dev_err_probe(dev, PTR_ERR(lvts_td->clk), "Failed to retrieve clock\n");

	res = platform_get_mem_or_io(pdev, 0);
	if (!res)
		return dev_err_probe(dev, (-ENXIO), "No IO resource\n");

	lvts_td->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
	if (IS_ERR(lvts_td->base))
		return dev_err_probe(dev, PTR_ERR(lvts_td->base), "Failed to map io resource\n");

	lvts_td->reset = devm_reset_control_get_by_index(dev, 0);
	if (IS_ERR(lvts_td->reset))
		return dev_err_probe(dev, PTR_ERR(lvts_td->reset), "Failed to get reset control\n");

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return dev_err_probe(dev, irq, "No irq resource\n");

	ret = lvts_domain_init(dev, lvts_td, lvts_data);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to initialize the lvts domain\n");

	/*
	 * At this point the LVTS is initialized and enabled. We can
	 * safely enable the interrupt.
	 */
	ret = devm_request_threaded_irq(dev, irq, NULL, lvts_irq_handler,
					IRQF_ONESHOT, dev_name(dev), lvts_td);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to request interrupt\n");

	platform_set_drvdata(pdev, lvts_td);

	return 0;
}

static int lvts_remove(struct platform_device *pdev)
{
	struct lvts_domain *lvts_td;
	int i;

	lvts_td = platform_get_drvdata(pdev);

	for (i = 0; i < lvts_td->num_lvts_ctrl; i++)
		lvts_ctrl_set_enable(&lvts_td->lvts_ctrl[i], false);

	lvts_debugfs_exit(lvts_td);

	return 0;
}

static const struct lvts_ctrl_data mt8195_lvts_data_ctrl[] = {
	{
		.cal_offset = { 0x04, 0x07 },
		.lvts_sensor = {
			{ .dt_id = MT8195_MCU_BIG_CPU0 },
			{ .dt_id = MT8195_MCU_BIG_CPU1 }
		},
		.num_lvts_sensor = 2,
		.offset = 0x0,
		.hw_tshut_temp = LVTS_HW_SHUTDOWN_MT8195,
	},
	{
		.cal_offset = { 0x0d, 0x10 },
		.lvts_sensor = {
			{ .dt_id = MT8195_MCU_BIG_CPU2 },
			{ .dt_id = MT8195_MCU_BIG_CPU3 }
		},
		.num_lvts_sensor = 2,
		.offset = 0x100,
		.hw_tshut_temp = LVTS_HW_SHUTDOWN_MT8195,
	},
	{
		.cal_offset = { 0x16, 0x19, 0x1c, 0x1f },
		.lvts_sensor = {
			{ .dt_id = MT8195_MCU_LITTLE_CPU0 },
			{ .dt_id = MT8195_MCU_LITTLE_CPU1 },
			{ .dt_id = MT8195_MCU_LITTLE_CPU2 },
			{ .dt_id = MT8195_MCU_LITTLE_CPU3 }
		},
		.num_lvts_sensor = 4,
		.offset = 0x200,
		.hw_tshut_temp = LVTS_HW_SHUTDOWN_MT8195,
	}
};

static const struct lvts_data mt8195_lvts_mcu_data = {
	.lvts_ctrl	= mt8195_lvts_data_ctrl,
	.num_lvts_ctrl	= ARRAY_SIZE(mt8195_lvts_data_ctrl),
};

static const struct of_device_id lvts_of_match[] = {
	{ .compatible = "mediatek,mt8195-lvts-mcu", .data = &mt8195_lvts_mcu_data },
	{},
};
MODULE_DEVICE_TABLE(of, lvts_of_match);

static struct platform_driver lvts_driver = {
	.probe = lvts_probe,
	.remove = lvts_remove,
	.driver = {
		.name = "mtk-lvts-thermal",
		.of_match_table = lvts_of_match,
	},
};
module_platform_driver(lvts_driver);

MODULE_AUTHOR("Balsam CHIHI <bchihi@baylibre.com>");
MODULE_DESCRIPTION("MediaTek LVTS Thermal Driver");
MODULE_LICENSE("GPL");