a155-U-u1/kernel-5.10/drivers/regulator/mtk-vmm-regulator.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2021 MediaTek Inc.
 */
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include <linux/printk.h>
#include <linux/pm_opp.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/remoteproc/mtk_ccu.h>
#include <clocksource/arm_arch_timer.h>

#define CREATE_TRACE_POINTS
#include "mtk-vmm-trace.h"
#include "internal.h"
#include "mtk-vmm-regulator.h"

static struct dentry *ispdvfs_debugfs_dir;
static struct regulator *vmm_reg;
static DECLARE_WAIT_QUEUE_HEAD(vmm_wait_queue);

#define REGULATOR_ID_VMM 0
#define AGING_MARGIN_MICROVOLT 12500
#define PM_QOS_VMM_ID 0x21

int mtk_ispdvfs_fix_dvfs;
EXPORT_SYMBOL(mtk_ispdvfs_fix_dvfs);
module_param(mtk_ispdvfs_fix_dvfs, int, 0644);

int mtk_ispdvfs_dbg_level;
EXPORT_SYMBOL(mtk_ispdvfs_dbg_level);
module_param(mtk_ispdvfs_dbg_level, int, 0644);

#define ISPDVFS_DBG
#ifdef ISPDVFS_DBG
#define ISP_LOGD(fmt, args...) \
	do { \
		if (mtk_ispdvfs_dbg_level & DVFS_DEBUG_LOG) \
			pr_notice("[ISPDVFS] %s(): " fmt "\n",\
				__func__, ##args); \
	} while (0)
#else
#define ISPDVFS_DBG(fmt, args...)
#endif
#define ISP_LOGI(fmt, args...) \
	pr_notice("[ISPDVFS] %s(): " fmt "\n", \
		__func__, ##args)
#define ISP_LOGE(fmt, args...) \
	pr_notice("[ISPDVFS] error %s(),%d: " fmt "\n", \
		__func__, __LINE__, ##args)
#define ISP_LOGF(fmt, args...) \
	pr_notice("[ISPDVFS] fatal %s(),%d: " fmt "\n", \
		__func__, __LINE__, ##args)

#define CREATE_REGULATOR(match, _name)	\
	.desc = {					\
		.name = match,				\
		.of_match = of_match_ptr(match),	\
		.ops = &vmm_apmcu_ops,		\
		.type = REGULATOR_VOLTAGE,		\
		.id = REGULATOR_ID_##_name,		\
		.owner = THIS_MODULE,			\
	}

struct vmm_regulator {
	struct regulator_desc	desc;
	struct dvfs_driver_data *dvfs_data;
	int is_enable;
};

struct ispdvfs_dbg_data {
	struct dvfs_driver_data *drv_data;
	struct regulator *reg;
	int max_voltage;
	bool reg_enable;
};

static struct ispdvfs_dbg_data *dbg_data;
static int fix_force_step(const char *val, const struct kernel_param *kp)
{
	int ret;
	u64 new_force_step;
	struct dvfs_driver_data *drv_data;
	struct dvfs_table *opp_table;
	struct dvfs_info *current_info;
	struct ccu_handle_info *ccu_handle;
	struct dvfs_ipc_info dvfs_ipi;

	ret = kstrtou64(val, 0, &new_force_step);
	if (ret) {
		ISP_LOGE("force set step failed: %d\n", ret);
		goto out;
	}

	if (!dbg_data) {
		ISP_LOGE("dbg_data is NULL\n");
		ret = PTR_ERR(dbg_data);
		goto out;
	}

	drv_data = dbg_data->drv_data;

	opp_table = &drv_data->opp_table;
	if (new_force_step >= opp_table->opp_num) {
		ISP_LOGE("Force level(%d) is out of range\n",
				new_force_step);
		ret = -EINVAL;
		goto out;
	}

	current_info = &(drv_data->current_dvfs);
	mutex_lock(&current_info->voltage_mutex);

	dvfs_ipi.minOppIdx = new_force_step;
	dvfs_ipi.maxOppIdx = new_force_step;
	ccu_handle = &(drv_data->ccu_handle);
	ret = mtk_ccu_rproc_ipc_send(
		ccu_handle->ccu_pdev,
		MTK_CCU_FEATURE_ISPDVFS,
		DVFS_VOLTAGE_UPDATE,
		(void *)&dvfs_ipi, sizeof(struct dvfs_ipc_info));
	if (ret) {
		ISP_LOGE("mtk_ccu_rproc_ipc_send(DVFS_VOLTAGE_UPDATE) fail(%lu)\n",
				arch_timer_read_counter());
		WARN_ON(1);
		goto Unlock_Mutex;
	}
	current_info->voltage_target = opp_table->voltage[new_force_step];
	trace_vmm__update_voltage(current_info->voltage_target);

Unlock_Mutex:
	mutex_unlock(&current_info->voltage_mutex);
out:
	return ret;
}

static struct kernel_param_ops set_force_step_ops = {
	.set = fix_force_step,
};
module_param_cb(force_step, &set_force_step_ops, NULL, 0644);
MODULE_PARM_DESC(force_step, "force vmm dvfs to specified step");

#define MAX_BUFFER_SIZE (PAGE_SIZE - 1)
static int show_setting(char *buf, const struct kernel_param *kp)
{
	struct dvfs_driver_data *drv_data;
	struct dvfs_table *table;
	struct dvfs_info *current_info;
	struct ccu_handle_info *ccu_handle;
	struct dvfs_ipc_vb vb_info;
	u32 i, ret;
	int written = 0;
	int improve;

	if (!dbg_data) {
		ISP_LOGE("dbg_data is NULL\n");
		return PTR_ERR(dbg_data);
	}
	drv_data = dbg_data->drv_data;

	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
		"mux number:%d\n", drv_data->num_muxes);
	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
		"mux:");
	for (i = 0; i < drv_data->num_muxes; i++) {
		written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
			"%s ", drv_data->muxes[i].mux_name);
	}
	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
		"\n");

	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
		"Support voltage:");

	table = &drv_data->opp_table;
	for (i = 0; i < table->opp_num; i++)
		written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
				"%d ", table->voltage[i]);
	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
		"\n");

	current_info = &(drv_data->current_dvfs);
	written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
			"Current voltage:%d\n", current_info->voltage_target);

	ccu_handle = &(drv_data->ccu_handle);
	vb_info.efuseValue = 0;
	ret = mtk_ccu_rproc_ipc_send(
		ccu_handle->ccu_pdev,
		MTK_CCU_FEATURE_ISPDVFS,
		DVFS_CCU_QUERY_VB,
		(void *)&vb_info, sizeof(struct dvfs_ipc_vb));
	if (ret) {
		ISP_LOGE("mtk_ccu_rproc_ipc_send(DVFS_CCU_QUERY_VB) fail(%lu)\n",
				arch_timer_read_counter());
	} else {
		if (drv_data->en_vb)
			written += snprintf(buf + written,
					MAX_BUFFER_SIZE - written,
					"Load supports VB\n");
		else
			written += snprintf(buf + written,
					MAX_BUFFER_SIZE - written,
					"Load does not support VB\n");
		written += snprintf(buf + written,
					MAX_BUFFER_SIZE - written,
					"Efuse reg:(0x%x)\n",
					vb_info.efuseValue);
	}

	if (table->opp_num <= MAX_OPP_STEP) {
		written += snprintf(buf + written, MAX_BUFFER_SIZE - written,
				"Final (After vb) voltage & improve:\n");
		for (i = 0; i < table->opp_num; i++) {
			improve = table->voltage[i] - vb_info.voltage[i];
			improve = (improve * 100)/table->voltage[i];
			written += snprintf(buf + written,
					MAX_BUFFER_SIZE - written,
					"volt(%d), improve(%d %%)\n",
					vb_info.voltage[i], improve);
		}
	}

	return written;
}
static struct kernel_param_ops dump_param_ops = {.get = show_setting};
module_param_cb(show_setting, &dump_param_ops, NULL, 0444);
MODULE_PARM_DESC(show_setting, "dump vmm dvfs current setting");

static int regulator_trace_consumers(struct regulator_dev *rdev)
{
	struct regulator *regulator;
	struct regulator_voltage *voltage;
	const char *devname;

	list_for_each_entry(regulator, &rdev->consumer_list, list) {
		voltage = &regulator->voltage[PM_SUSPEND_ON];
		devname = regulator->dev ?
				dev_name(regulator->dev) : "deviceless";
		trace_mtk_pm_qos_update_request(PM_QOS_VMM_ID,
				voltage->min_uV, devname);
	}

	return 0;
}

static int force_voltage(void *data, u64 val)
{
	struct ispdvfs_dbg_data *dbg_data = (struct ispdvfs_dbg_data *)data;
	int voltage = (int)val;

	ISP_LOGI("Force votage(%d)", voltage);

	if (!dbg_data->reg_enable) {
		regulator_enable(dbg_data->reg);
		dbg_data->reg_enable = true;
	}

	/* Disable vmm regulator when voltage is 0 */
	if (dbg_data->reg_enable && !voltage) {
		regulator_disable(dbg_data->reg);
		dbg_data->reg_enable = false;
	}

	if (IS_ERR(dbg_data->reg)) {
		ISP_LOGE("can't get dvfs regulator\n");
		return PTR_ERR(dbg_data->reg);
	}

	regulator_set_voltage(dbg_data->reg, voltage, INT_MAX);

	return 0;
}

static int force_opp_level(void *data, u64 val)
{
	struct ispdvfs_dbg_data *dbg_data = (struct ispdvfs_dbg_data *)data;
	struct dvfs_driver_data *drv_data;
	struct dvfs_table *opp_table;

	ISP_LOGI("Force opp level(%d)", val);

	if (IS_ERR(dbg_data)) {
		ISP_LOGE("dbg_data is NULL\n");
		return PTR_ERR(dbg_data);
	}

	if (IS_ERR(dbg_data->reg)) {
		ISP_LOGE("can't get dvfs regulator\n");
		return PTR_ERR(dbg_data->reg);
	}

	drv_data = dbg_data->drv_data;
	if (IS_ERR(drv_data)) {
		ISP_LOGE("dbg_data is NULL\n");
		return PTR_ERR(drv_data);
	}
	opp_table = &(drv_data->opp_table);

	if (!dbg_data->reg_enable) {
		regulator_enable(dbg_data->reg);
		dbg_data->reg_enable = true;
	}

	if (val < opp_table->opp_num)
		regulator_set_voltage(dbg_data->reg, opp_table->voltage[val], INT_MAX);
	else {
		ISP_LOGI("Opp level is not in range.\n");
		if (dbg_data->reg_enable) {
			regulator_disable(dbg_data->reg);
			dbg_data->reg_enable = false;
		}
	}

	return 0;
}

static void set_all_muxes(struct dvfs_driver_data *drv_data, u32 opp_level)
{
	u32 num_muxes = drv_data->num_muxes;
	u32 i;
	struct clk *mux, *clk_src;
	s32 err;

	for (i = 0; i < num_muxes; i++) {
		mux = drv_data->muxes[i].mux;
		clk_src = drv_data->muxes[i].clk_src[opp_level];
		err = clk_prepare_enable(mux);
		if (err) {
			ISP_LOGE("prepare mux(%s) fail:%d opp_level:%d\n",
			drv_data->muxes[i].mux_name, err, opp_level);
			continue;
		}
		err = clk_set_parent(mux, clk_src);
		if (err)
			ISP_LOGE("set parent(%s) fail:%d opp_level:%d\n",
					drv_data->muxes[i].mux_name, err, opp_level);
		clk_disable_unprepare(mux);
	}
}

static int enable_all_muxes(struct dvfs_driver_data *drv_data)
{
	u32 num_muxes;
	u32 i, j;
	struct clk *mux;
	s32 err;

	if (!drv_data) {
		ISP_LOGE("drv_data is NULL");
		return PTR_ERR(drv_data);
	}
	num_muxes = drv_data->num_muxes;

	for (i = 0; i < num_muxes; i++) {
		mux = drv_data->muxes[i].mux;
		err = clk_prepare_enable(mux);
		if (err) {
			ISP_LOGE("prepare mux(%s) fail:%d\n",
				drv_data->muxes[i].mux_name, err);

			for (j = 0; j < i; j++) {
				mux = drv_data->muxes[j].mux;
				clk_disable_unprepare(mux);
			}

			return err;
		}
	}

	return err;
}

static int disable_all_muxes(struct dvfs_driver_data *drv_data)
{
	u32 num_muxes;
	u32 i;
	struct clk *mux;

	if (!drv_data) {
		ISP_LOGE("drv_data is NULL");
		return PTR_ERR(drv_data);
	}
	num_muxes = drv_data->num_muxes;

	for (i = 0; i < num_muxes; i++) {
		mux = drv_data->muxes[i].mux;
		clk_disable_unprepare(mux);
	}

	return 0;
}

static void ccu_ipc_update_dvfs(uint32_t data, uint32_t len, void *priv)
{
	ISP_LOGD("Current VMM voltage(%d)", data);
	trace_vmm__update_voltage(data);
}

static int vmm_init_dvfs(struct ccu_handle_info *ccu_handle)
{
	phandle handle;
	struct device_node *node = NULL, *rproc_np = NULL;
	int ret = 0;

	node = of_find_compatible_node(NULL, NULL, "mediatek,ispdvfs");
	if (node == NULL) {
		ISP_LOGE("of_find mediatek,ispdvfs fail\n");
		ret = PTR_ERR(node);
		goto error_handle;
	}

	ret = of_property_read_u32(node, "mediatek,ccu_rproc", &handle);
	if (ret < 0) {
		ISP_LOGE("get CCU phandle fail\n");
		goto error_handle;
	}

	rproc_np = of_find_node_by_phandle(handle);
	if (rproc_np) {
		ccu_handle->ccu_pdev = of_find_device_by_node(rproc_np);
		if (ccu_handle->ccu_pdev == NULL) {
			ISP_LOGF("find ccu rproc pdev fail\n");
			ret = PTR_ERR(ccu_handle->ccu_pdev);
			goto error_handle;
		}
		// Register callback
		mtk_ccu_ipc_register(ccu_handle->ccu_pdev,
				MTK_CCU_MSG_TO_APMCU_DVFS_STATUS,
				ccu_ipc_update_dvfs, NULL);

		ccu_handle->handle = handle;

		ISP_LOGD("get ccu proc pdev successfully\n");
	}

	return ret;

error_handle:
	ccu_handle->ccu_pdev = NULL;
	WARN_ON(ret);
	return ret;
}

static int get_idx_by_voltage(
		int voltage,
		const struct dvfs_table *table,
		int *min_volt,
		int *max_volt)
{
	u32 i = 0;

	if (!table || !min_volt || !max_volt) {
		ISP_LOGE("some arguments are NULL\n");
		return -EINVAL;
	}

	for (i = 0; i < table->opp_num; i++) {
		if (voltage == table->voltage[i]) {
			*min_volt = i;
			*max_volt = i;
			break;
		} else if (voltage < table->voltage[i]) {
			if (i >= 1) {
				*min_volt = i - 1;
				*max_volt = i;
			} else {
				*min_volt = i;
				*max_volt = i;
			}
			break;
		}
	}

	if (i == table->opp_num) {
		*min_volt = i - 1;
		*max_volt = i - 1;
	}

	return 0;
}

static int ccu_set_voltage(struct regulator_dev *rdev,
		int min_uV, int max_uV, unsigned int *selector)
{
	int ret = 0;
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *drv_data;
	struct ccu_handle_info *ccu_handle;
	struct dvfs_info *current_info;
	struct dvfs_ipc_info dvfs_ipi;

	regulator = rdev_get_drvdata(rdev);
	if (!regulator) {
		ISP_LOGE("rdev_get_drvdata ptr is null");
		return PTR_ERR(regulator);
	}

	drv_data = regulator->dvfs_data;
	if (!drv_data) {
		ISP_LOGE("drv_data ptr is null");
		return PTR_ERR(drv_data);
	}

	if (drv_data->disable_dvfs || mtk_ispdvfs_fix_dvfs)
		return 0;

	/* record vmm & related consumer traces */
	regulator_trace_consumers(rdev);

	current_info = &(drv_data->current_dvfs);
	mutex_lock(&current_info->voltage_mutex);

	if (current_info->voltage_target == min_uV) {
		ret = 0;
		goto Unlock_Mutex;
	}

	ret = get_idx_by_voltage(min_uV,
			&drv_data->opp_table,
			&dvfs_ipi.minOppIdx,
			&dvfs_ipi.maxOppIdx);
	if (ret) {
		ISP_LOGE("get voltage index fail\n");
		goto Unlock_Mutex;
	}

	ccu_handle = &(drv_data->ccu_handle);
	ret = mtk_ccu_rproc_ipc_send(
		ccu_handle->ccu_pdev,
		MTK_CCU_FEATURE_ISPDVFS,
		DVFS_VOLTAGE_UPDATE,
		(void *)&dvfs_ipi, sizeof(struct dvfs_ipc_info));
	if (ret) {
		ISP_LOGE("mtk_ccu_rproc_ipc_send(DVFS_VOLTAGE_UPDATE) fail(%lu)\n",
				arch_timer_read_counter());
		WARN_ON(1);
		goto Unlock_Mutex;
	}

	current_info->voltage_target = min_uV;

	ISP_LOGD("CCU VMM set voltage (%d) max level(%d)",
			min_uV, dvfs_ipi.maxOppIdx);

	if (dvfs_ipi.maxOppIdx == dvfs_ipi.minOppIdx)
		trace_vmm__update_voltage(min_uV);

Unlock_Mutex:
	mutex_unlock(&current_info->voltage_mutex);

	return ret;
}

static int apmcu_set_voltage(struct regulator_dev *rdev,
		int min_uV, int max_uV, unsigned int *selector)
{
	int ret = 0;
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *drv_data;
	struct dvfs_info *current_info;
	struct dvfs_table *table;
	int target_voltage = min_uV;
	u32 cur_opp_idx = 0, prev_opp_idx = 0;
	u32 i;

	trace_vmm__update_voltage(min_uV);

	regulator = rdev_get_drvdata(rdev);
	if (!regulator) {
		ISP_LOGE("rdev_get_drvdata ptr is null");
		return PTR_ERR(regulator);
	}

	drv_data = regulator->dvfs_data;
	if (!drv_data) {
		ISP_LOGE("drv_data ptr is null");
		return PTR_ERR(drv_data);
	}
	table = &(drv_data->opp_table);

	current_info = &(drv_data->current_dvfs);
	mutex_lock(&current_info->voltage_mutex);

	for (i = 0; i < table->opp_num; i++) {
		if (min_uV <= table->voltage[i]) {
			cur_opp_idx = i;
			break;
		}
	}
	prev_opp_idx = current_info->opp_level;

	if (drv_data->simulate_aging)
		target_voltage -= AGING_MARGIN_MICROVOLT;

	if (cur_opp_idx < prev_opp_idx) {
		/* Upldate Frequency firstly */
		set_all_muxes(drv_data, cur_opp_idx);

		/* Then update voltage */
		regulator_set_voltage(vmm_reg, target_voltage, INT_MAX);
		current_info->voltage_target = min_uV;
		current_info->opp_level = cur_opp_idx;
		mutex_unlock(&current_info->voltage_mutex);
	} else {
		/* Update voltage firstly */
		regulator_set_voltage(vmm_reg, target_voltage, INT_MAX);
		current_info->voltage_target = min_uV;
		current_info->opp_level = cur_opp_idx;
		mutex_unlock(&current_info->voltage_mutex);

		/* Then update frequency */
		set_all_muxes(drv_data, cur_opp_idx);
	}

	ISP_LOGD("VMM update voltage(%d)", target_voltage);

	return ret;
}

static int vmm_get_voltage(struct regulator_dev *rdev)
{
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *drv_data;
	struct dvfs_info *current_info;
	int current_voltage = DEFAULT_VOLTAGE;

	regulator = rdev_get_drvdata(rdev);
	if (!regulator) {
		ISP_LOGE("rdev_get_drvdata ptr is null");
		goto out;
	}

	drv_data = regulator->dvfs_data;
	if (!drv_data) {
		ISP_LOGE("drv_data ptr is null");
		goto out;
	}

	current_info = &(drv_data->current_dvfs);
	mutex_lock(&current_info->voltage_mutex);
	current_voltage = current_info->voltage_target;
	mutex_unlock(&current_info->voltage_mutex);

out:
	return current_voltage;
}

static void vmm_init_opp_table(struct dvfs_driver_data *data)
{
	struct dvfs_table *opp_table = &(data->opp_table);
	struct dev_pm_opp *opp;
	unsigned long freq = 0;
	int clk_num = 0, i = 0;

	dev_pm_opp_of_add_table(data->dev);
	clk_num = dev_pm_opp_get_opp_count(data->dev);
	while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(data->dev, &freq))) {
		opp_table->frequency[i] = freq;
		opp_table->voltage[i] = dev_pm_opp_get_voltage(opp);
		freq++;
		i++;
		dev_pm_opp_put(opp);
	}
	opp_table->opp_num = clk_num;
	for (i = 0; i < opp_table->opp_num; i++) {
		ISP_LOGD("Opp table: idx=%d, clk=%d volt=%d\n",
				i, opp_table->frequency[i], opp_table->voltage[i]);
	}
}

static int vmm_enable_regulator(struct regulator_dev *rdev)
{
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *drv_data;
	struct ccu_handle_info *ccu_handle;
	struct dvfs_ipc_init dvfs_ipi_init;
	int ret;

	ISP_LOGI("Enable vmm regulator");

	regulator = rdev_get_drvdata(rdev);
	if (!regulator) {
		ISP_LOGE("rdev_get_drvdata ptr is null");
		ret = PTR_ERR(regulator);
		goto error_handle;
	}

	drv_data = regulator->dvfs_data;
	if (!drv_data) {
		ISP_LOGE("dvfs_data ptr is null");
		ret = PTR_ERR(drv_data);
		goto error_handle;
	}

	if (!drv_data->mux_is_enable) {
		/* Enable mux so that we could keep mux life cycle */
		ret = enable_all_muxes(drv_data);
		if (ret) {
			ISP_LOGE("enable all mux fail\n");
			goto error_handle;
		}
		drv_data->mux_is_enable = true;
	}

	ccu_handle = &(drv_data->ccu_handle);
	ret = vmm_init_dvfs(ccu_handle);
	if (ret) {
		ISP_LOGE("boot ccu rproc fail\n");
		goto error_handle;
	}

	dvfs_ipi_init.needVoltageBin = drv_data->en_vb;
	dvfs_ipi_init.needSimAging = drv_data->simulate_aging;
	dvfs_ipi_init.needCbFromMicroP
			= mtk_ispdvfs_dbg_level & DVFS_DEBUG_MICROP;
	ret = mtk_ccu_rproc_ipc_send(
		ccu_handle->ccu_pdev,
		MTK_CCU_FEATURE_ISPDVFS,
		DVFS_CCU_INIT,
		(void *)&dvfs_ipi_init, sizeof(struct dvfs_ipc_init));
	if (ret) {
		ISP_LOGE("mtk_ccu_rproc_ipc_send(DVFS_CCU_INIT) fail\n");
		goto error_handle;
	}


	regulator->is_enable = 1;

	return 0;

error_handle:
	WARN_ON(ret);
	return ret;
}

static int vmm_disable_regulator(struct regulator_dev *rdev)
{
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *dvfs_data;
	struct ccu_handle_info *ccu_handle;
	struct dvfs_info *current_info;
	int exit = 1;
	int ret = 0;

	ISP_LOGI("Disable vmm regulator");

	regulator = rdev_get_drvdata(rdev);
	if (!regulator) {
		ISP_LOGE("rdev_get_drvdata ptr is null");
		ret = PTR_ERR(regulator);
		goto error_handle;
	}

	dvfs_data = regulator->dvfs_data;
	if (!dvfs_data) {
		ISP_LOGE("dvfs_data ptr is null");
		ret = PTR_ERR(dvfs_data);
		goto error_handle;
	}

	if (dvfs_data->mux_is_enable) {
		disable_all_muxes(dvfs_data);
		dvfs_data->mux_is_enable = false;
	}

	ccu_handle = &(dvfs_data->ccu_handle);
	ret = mtk_ccu_rproc_ipc_send(
		ccu_handle->ccu_pdev,
		MTK_CCU_FEATURE_ISPDVFS,
		DVFS_CCU_DVFS_RESET,
		(void *)&exit, sizeof(exit));
	if (ret) {
		ISP_LOGE("ccu ipc fail(DVFS_CCU_DVFS_RESET) fail");
		goto error_handle;
	}

	memset(ccu_handle, 0, sizeof(*ccu_handle));

	current_info = &(dvfs_data->current_dvfs);
	current_info->voltage_target = DEFAULT_VOLTAGE;

	regulator->is_enable = 0;
	return 0;

error_handle:
	WARN_ON(ret);
	return ret;
}

static int vmm_is_enabled(struct regulator_dev *rdev)
{
	struct vmm_regulator *regulator = rdev_get_drvdata(rdev);

	return regulator->is_enable;
}

static const struct regulator_ops vmm_apmcu_ops = {
	.list_voltage = regulator_list_voltage_table,
	.set_voltage = apmcu_set_voltage,
	.get_voltage = vmm_get_voltage,
	.enable = vmm_enable_regulator,
	.disable = vmm_disable_regulator,
	.is_enabled = vmm_is_enabled,
};

static const struct regulator_ops vmm_ccu_ops = {
	.list_voltage = regulator_list_voltage_table,
	.set_voltage = ccu_set_voltage,
	.get_voltage = vmm_get_voltage,
	.enable = vmm_enable_regulator,
	.disable = vmm_disable_regulator,
	.is_enabled = vmm_is_enabled,
};

static struct vmm_regulator platform_regulators = {
	CREATE_REGULATOR("vmm-proxy", VMM),
};

static const struct of_device_id mtk_vmm_regulator_match[] = {
	{
		.compatible = "mediatek,ispdvfs",
		.data = &platform_regulators,
	}, {
		/* sentinel */
	},
};

DEFINE_SIMPLE_ATTRIBUTE(force_voltage_ops, NULL, force_voltage, "%llu\n");
DEFINE_SIMPLE_ATTRIBUTE(force_opp_level_ops, NULL, force_opp_level, "%llu\n");
static int vmm_regulator_probe(struct platform_device *pdev)
{
	const struct of_device_id *match;
	struct device *dev = &pdev->dev;
	struct regulator_config config = { };
	struct regulator_dev *rdev;
	struct vmm_regulator *regulator;
	struct dvfs_driver_data *dvfs_data;
	struct dvfs_table *opp_table;
	struct dvfs_info *current_dvfs;
	int support_micro_processor = 0;
	u32 simulate_aging = 0, en_vb = 0;
	struct property *mux_prop, *clksrc_prop;
	const char *mux_name, *clksrc_name;
	u32 num_mux = 0;
	u32 num_clksrc;
	char prop_name[32];
	struct dentry *dentry;
	u32 opp_level = DEFAULT_VOLTAGE_LEVEL;
	u32 disable_dvfs = 0;

	match = of_match_node(mtk_vmm_regulator_match, dev->of_node);
	if (!match) {
		ISP_LOGE("invalid compatible string\n");
		return -ENODEV;
	}

	dvfs_data = devm_kzalloc(dev, sizeof(*dvfs_data), GFP_KERNEL);
	if (!dvfs_data) {
		ISP_LOGE("devm_kzalloc dvfs_data fail\n");
		return -ENODEV;
	}
	dvfs_data->dev = dev;

	vmm_init_opp_table(dvfs_data);

	current_dvfs = &(dvfs_data->current_dvfs);
	mutex_init(&current_dvfs->voltage_mutex);
	opp_table = &(dvfs_data->opp_table);
	current_dvfs->voltage_target = opp_table->voltage[opp_level];
	current_dvfs->opp_level = opp_level;

	of_property_for_each_string(
		dev->of_node, "mediatek,support_mux", mux_prop, mux_name) {
		if (num_mux >= MAX_MUX_NUM) {
			ISP_LOGE("Too many items in support_mux\n");
			return -EINVAL;
		}
		dvfs_data->muxes[num_mux].mux = devm_clk_get(dev, mux_name);
		dvfs_data->muxes[num_mux].mux_name = mux_name;
		snprintf(prop_name, sizeof(prop_name)-1,
			"mediatek,mux_%s", mux_name);
		num_clksrc = 0;
		of_property_for_each_string(
			dev->of_node, prop_name, clksrc_prop, clksrc_name) {
			if (num_clksrc >= MAX_OPP_STEP) {
				ISP_LOGE("Too many items in %s\n", prop_name);
				return -EINVAL;
			}
			dvfs_data->muxes[num_mux].clk_src[num_clksrc] =
				devm_clk_get(dev, clksrc_name);
			num_clksrc++;
		}
		num_mux++;
	}
	dvfs_data->num_muxes = num_mux;
	dvfs_data->mux_is_enable = false;

	/* Real regualtor instance which controls vmm directly */
	vmm_reg = devm_regulator_get(dev, "buck-vmm");
	if (IS_ERR(vmm_reg))
		ISP_LOGE("could not get buck-vmm regulator\n");

	of_property_read_u32(dev->of_node,
		"mediatek,disable_dvfs",
		&disable_dvfs);
	dvfs_data->disable_dvfs = disable_dvfs;

	of_property_read_u32(dev->of_node,
		"simulate_aging",
		&simulate_aging);
	dvfs_data->simulate_aging = simulate_aging;

	of_property_read_u32(dev->of_node,
		"en_vb",
		&en_vb);
	dvfs_data->en_vb = en_vb;

	regulator = (struct vmm_regulator *)(match->data);
	regulator->dvfs_data = dvfs_data;
	regulator->desc.n_voltages = ARRAY_SIZE(opp_table->voltage);
	regulator->desc.volt_table = opp_table->voltage;

	of_property_read_u32(dev->of_node,
		"mediatek,support_micro_processor",
		&support_micro_processor);
	if (support_micro_processor)
		regulator->desc.ops = &vmm_ccu_ops;
	regulator->is_enable = 0;

	config.dev = dev;
	config.driver_data = regulator;
	rdev = devm_regulator_register(dev,
			&regulator->desc,
			&config);
	if (IS_ERR(rdev)) {
		ISP_LOGE("failed to register %s\n",
			regulator->desc.name);
		goto fail_destroy_mutex;
	}

	ispdvfs_debugfs_dir = debugfs_create_dir("ispdvfs", NULL);
	if (IS_ERR(ispdvfs_debugfs_dir))
		ISP_LOGE("Failed to create debugfs dir ispdvfs: %ld\n",
			PTR_ERR(ispdvfs_debugfs_dir));

	dbg_data = devm_kzalloc(dev, sizeof(*dbg_data), GFP_KERNEL);
	if (!dbg_data) {
		ISP_LOGE("devm_kzalloc fail: %ld\n",
			PTR_ERR(dbg_data));
		goto fail_destroy_mutex;
	}
	dbg_data->drv_data = dvfs_data;
	dbg_data->reg = devm_regulator_get(dev, "dvfs-vmm");
	dbg_data->max_voltage = opp_table->voltage[opp_table->opp_num - 1];
	dbg_data->reg_enable = false;
	dentry = debugfs_create_file("force_voltage", 0200,
			ispdvfs_debugfs_dir, dbg_data, &force_voltage_ops);
	if (IS_ERR(dentry))
		ISP_LOGE("Failed to create debugfs force_voltage: %ld\n",
			PTR_ERR(dentry));

	/* Need to remove. We do not allow select operating point level */
	dentry = debugfs_create_file("force_opp_level", 0200,
			ispdvfs_debugfs_dir, dbg_data, &force_opp_level_ops);
	if (IS_ERR(dentry))
		ISP_LOGE("Failed to create debugfs force_opp_level: %ld\n",
			PTR_ERR(dentry));

	return 0;

fail_destroy_mutex:
	mutex_destroy(&current_dvfs->voltage_mutex);
	return -ENODEV;
}

static struct platform_driver mtk_vmm_regulator_driver = {
	.driver = {
		.name  = "mtk-vmm-regulator",
		.owner = THIS_MODULE,
		.of_match_table = mtk_vmm_regulator_match,
	},
	.probe = vmm_regulator_probe,
};

static int __init mtk_vmm_regulator_init(void)
{
	s32 status;

	status = platform_driver_register(&mtk_vmm_regulator_driver);
	if (status) {
		ISP_LOGE("Failed to register VMM driver(%d)\n", status);
		return -ENODEV;
	}
	return 0;
}
subsys_initcall(mtk_vmm_regulator_init);

static void __exit mtk_vmm_regulator_exit(void)
{
	platform_driver_unregister(&mtk_vmm_regulator_driver);
}
module_exit(mtk_vmm_regulator_exit);

MODULE_AUTHOR("Yuan Jung Kuo <yuan-jung.kuo@mediatek.com>");
MODULE_DESCRIPTION("VMM regulator driver");
MODULE_LICENSE("GPL v2");