// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
 * Copyright (c) 2014,2015, Linaro Ltd.
 *
 * SAW power controller driver
 */

#include <linux/bitfield.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/linear_range.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/smp.h>

#include <linux/regulator/driver.h>

#include <soc/qcom/spm.h>

#define FIELD_SET(current, mask, val)	\
	(((current) & ~(mask)) | FIELD_PREP((mask), (val)))

#define SPM_CTL_INDEX		0x7f
#define SPM_CTL_INDEX_SHIFT	4
#define SPM_CTL_EN		BIT(0)

/* These registers might be specific to SPM 1.1 */
#define SPM_VCTL_VLVL			GENMASK(7, 0)
#define SPM_PMIC_DATA_0_VLVL		GENMASK(7, 0)
#define SPM_PMIC_DATA_1_MIN_VSEL	GENMASK(5, 0)
#define SPM_PMIC_DATA_1_MAX_VSEL	GENMASK(21, 16)

#define SPM_1_1_AVS_CTL_AVS_ENABLED	BIT(27)
#define SPM_AVS_CTL_MAX_VLVL		GENMASK(22, 17)
#define SPM_AVS_CTL_MIN_VLVL		GENMASK(15, 10)

enum spm_reg {
	SPM_REG_CFG,
	SPM_REG_SPM_CTL,
	SPM_REG_DLY,
	SPM_REG_PMIC_DLY,
	SPM_REG_PMIC_DATA_0,
	SPM_REG_PMIC_DATA_1,
	SPM_REG_VCTL,
	SPM_REG_SEQ_ENTRY,
	SPM_REG_STS0,
	SPM_REG_STS1,
	SPM_REG_PMIC_STS,
	SPM_REG_AVS_CTL,
	SPM_REG_AVS_LIMIT,
	SPM_REG_RST,
	SPM_REG_NR,
};

#define MAX_PMIC_DATA		2
#define MAX_SEQ_DATA		64

struct spm_reg_data {
	const u16 *reg_offset;
	u32 spm_cfg;
	u32 spm_dly;
	u32 pmic_dly;
	u32 pmic_data[MAX_PMIC_DATA];
	u32 avs_ctl;
	u32 avs_limit;
	u8 seq[MAX_SEQ_DATA];
	u8 start_index[PM_SLEEP_MODE_NR];

	smp_call_func_t set_vdd;
	/* for now we support only a single range */
	struct linear_range *range;
	unsigned int ramp_delay;
	unsigned int init_uV;
};

struct spm_driver_data {
	void __iomem *reg_base;
	const struct spm_reg_data *reg_data;
	struct device *dev;
	unsigned int volt_sel;
	int reg_cpu;
};

static const u16 spm_reg_offset_v4_1[SPM_REG_NR] = {
	[SPM_REG_AVS_CTL]	= 0x904,
	[SPM_REG_AVS_LIMIT]	= 0x908,
};

static const struct spm_reg_data spm_reg_660_gold_l2  = {
	.reg_offset = spm_reg_offset_v4_1,
	.avs_ctl = 0x1010031,
	.avs_limit = 0x4580458,
};

static const struct spm_reg_data spm_reg_660_silver_l2  = {
	.reg_offset = spm_reg_offset_v4_1,
	.avs_ctl = 0x101c031,
	.avs_limit = 0x4580458,
};

static const struct spm_reg_data spm_reg_8998_gold_l2  = {
	.reg_offset = spm_reg_offset_v4_1,
	.avs_ctl = 0x1010031,
	.avs_limit = 0x4700470,
};

static const struct spm_reg_data spm_reg_8998_silver_l2  = {
	.reg_offset = spm_reg_offset_v4_1,
	.avs_ctl = 0x1010031,
	.avs_limit = 0x4200420,
};

static const u16 spm_reg_offset_v3_0[SPM_REG_NR] = {
	[SPM_REG_CFG]		= 0x08,
	[SPM_REG_SPM_CTL]	= 0x30,
	[SPM_REG_DLY]		= 0x34,
	[SPM_REG_SEQ_ENTRY]	= 0x400,
};

/* SPM register data for 8909 */
static const struct spm_reg_data spm_reg_8909_cpu = {
	.reg_offset = spm_reg_offset_v3_0,
	.spm_cfg = 0x1,
	.spm_dly = 0x3C102800,
	.seq = { 0x60, 0x03, 0x60, 0x0B, 0x0F, 0x20, 0x10, 0x80, 0x30, 0x90,
		0x5B, 0x60, 0x03, 0x60, 0x76, 0x76, 0x0B, 0x94, 0x5B, 0x80,
		0x10, 0x26, 0x30, 0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 5,
};

/* SPM register data for 8916 */
static const struct spm_reg_data spm_reg_8916_cpu = {
	.reg_offset = spm_reg_offset_v3_0,
	.spm_cfg = 0x1,
	.spm_dly = 0x3C102800,
	.seq = { 0x60, 0x03, 0x60, 0x0B, 0x0F, 0x20, 0x10, 0x80, 0x30, 0x90,
		0x5B, 0x60, 0x03, 0x60, 0x3B, 0x76, 0x76, 0x0B, 0x94, 0x5B,
		0x80, 0x10, 0x26, 0x30, 0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 5,
};

static const struct spm_reg_data spm_reg_8939_cpu = {
	.reg_offset = spm_reg_offset_v3_0,
	.spm_cfg = 0x1,
	.spm_dly = 0x3C102800,
	.seq = { 0x60, 0x03, 0x60, 0x0B, 0x0F, 0x20, 0x50, 0x1B, 0x10, 0x80,
		0x30, 0x90, 0x5B, 0x60, 0x50, 0x03, 0x60, 0x76, 0x76, 0x0B,
		0x50, 0x1B, 0x94, 0x5B, 0x80, 0x10, 0x26, 0x30, 0x50, 0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 5,
};

static const u16 spm_reg_offset_v2_3[SPM_REG_NR] = {
	[SPM_REG_CFG]		= 0x08,
	[SPM_REG_SPM_CTL]	= 0x30,
	[SPM_REG_DLY]		= 0x34,
	[SPM_REG_PMIC_DATA_0]	= 0x40,
	[SPM_REG_PMIC_DATA_1]	= 0x44,
};

/* SPM register data for 8976 */
static const struct spm_reg_data spm_reg_8976_gold_l2 = {
	.reg_offset = spm_reg_offset_v2_3,
	.spm_cfg = 0x14,
	.spm_dly = 0x3c11840a,
	.pmic_data[0] = 0x03030080,
	.pmic_data[1] = 0x00030000,
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 3,
};

static const struct spm_reg_data spm_reg_8976_silver_l2 = {
	.reg_offset = spm_reg_offset_v2_3,
	.spm_cfg = 0x14,
	.spm_dly = 0x3c102800,
	.pmic_data[0] = 0x03030080,
	.pmic_data[1] = 0x00030000,
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 2,
};

static const u16 spm_reg_offset_v2_1[SPM_REG_NR] = {
	[SPM_REG_CFG]		= 0x08,
	[SPM_REG_SPM_CTL]	= 0x30,
	[SPM_REG_DLY]		= 0x34,
	[SPM_REG_SEQ_ENTRY]	= 0x80,
};

/* SPM register data for 8974, 8084 */
static const struct spm_reg_data spm_reg_8974_8084_cpu  = {
	.reg_offset = spm_reg_offset_v2_1,
	.spm_cfg = 0x1,
	.spm_dly = 0x3C102800,
	.seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
		0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
		0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 3,
};

/* SPM register data for 8226 */
static const struct spm_reg_data spm_reg_8226_cpu  = {
	.reg_offset = spm_reg_offset_v2_1,
	.spm_cfg = 0x0,
	.spm_dly = 0x3C102800,
	.seq = { 0x60, 0x03, 0x60, 0x0B, 0x0F, 0x20, 0x10, 0x80, 0x30, 0x90,
		0x5B, 0x60, 0x03, 0x60, 0x3B, 0x76, 0x76, 0x0B, 0x94, 0x5B,
		0x80, 0x10, 0x26, 0x30, 0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 5,
};

static const u16 spm_reg_offset_v1_1[SPM_REG_NR] = {
	[SPM_REG_CFG]		= 0x08,
	[SPM_REG_STS0]		= 0x0c,
	[SPM_REG_STS1]		= 0x10,
	[SPM_REG_VCTL]		= 0x14,
	[SPM_REG_AVS_CTL]	= 0x18,
	[SPM_REG_SPM_CTL]	= 0x20,
	[SPM_REG_PMIC_DLY]	= 0x24,
	[SPM_REG_PMIC_DATA_0]	= 0x28,
	[SPM_REG_PMIC_DATA_1]	= 0x2C,
	[SPM_REG_SEQ_ENTRY]	= 0x80,
};

static void smp_set_vdd_v1_1(void *data);

/* SPM register data for 8064 */
static struct linear_range spm_v1_1_regulator_range =
	REGULATOR_LINEAR_RANGE(700000, 0, 56, 12500);

static const struct spm_reg_data spm_reg_8064_cpu = {
	.reg_offset = spm_reg_offset_v1_1,
	.spm_cfg = 0x1F,
	.pmic_dly = 0x02020004,
	.pmic_data[0] = 0x0084009C,
	.pmic_data[1] = 0x00A4001C,
	.seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
		0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
	.start_index[PM_SLEEP_MODE_STBY] = 0,
	.start_index[PM_SLEEP_MODE_SPC] = 2,
	.set_vdd = smp_set_vdd_v1_1,
	.range = &spm_v1_1_regulator_range,
	.init_uV = 1300000,
	.ramp_delay = 1250,
};

static inline void spm_register_write(struct spm_driver_data *drv,
					enum spm_reg reg, u32 val)
{
	if (drv->reg_data->reg_offset[reg])
		writel_relaxed(val, drv->reg_base +
				drv->reg_data->reg_offset[reg]);
}

/* Ensure a guaranteed write, before return */
static inline void spm_register_write_sync(struct spm_driver_data *drv,
					enum spm_reg reg, u32 val)
{
	u32 ret;

	if (!drv->reg_data->reg_offset[reg])
		return;

	do {
		writel_relaxed(val, drv->reg_base +
				drv->reg_data->reg_offset[reg]);
		ret = readl_relaxed(drv->reg_base +
				drv->reg_data->reg_offset[reg]);
		if (ret == val)
			break;
		cpu_relax();
	} while (1);
}

static inline u32 spm_register_read(struct spm_driver_data *drv,
				    enum spm_reg reg)
{
	return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
}

void spm_set_low_power_mode(struct spm_driver_data *drv,
			    enum pm_sleep_mode mode)
{
	u32 start_index;
	u32 ctl_val;

	start_index = drv->reg_data->start_index[mode];

	ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
	ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
	ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
	ctl_val |= SPM_CTL_EN;
	spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
}

static int spm_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
{
	struct spm_driver_data *drv = rdev_get_drvdata(rdev);

	drv->volt_sel = selector;

	/* Always do the SAW register writes on the corresponding CPU */
	return smp_call_function_single(drv->reg_cpu, drv->reg_data->set_vdd, drv, true);
}

static int spm_get_voltage_sel(struct regulator_dev *rdev)
{
	struct spm_driver_data *drv = rdev_get_drvdata(rdev);

	return drv->volt_sel;
}

static const struct regulator_ops spm_reg_ops = {
	.set_voltage_sel	= spm_set_voltage_sel,
	.get_voltage_sel	= spm_get_voltage_sel,
	.list_voltage		= regulator_list_voltage_linear_range,
	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
};

static void smp_set_vdd_v1_1(void *data)
{
	struct spm_driver_data *drv = data;
	unsigned int vctl, data0, data1, avs_ctl, sts;
	unsigned int vlevel, volt_sel;
	bool avs_enabled;

	volt_sel = drv->volt_sel;
	vlevel = volt_sel | 0x80; /* band */

	avs_ctl = spm_register_read(drv, SPM_REG_AVS_CTL);
	vctl = spm_register_read(drv, SPM_REG_VCTL);
	data0 = spm_register_read(drv, SPM_REG_PMIC_DATA_0);
	data1 = spm_register_read(drv, SPM_REG_PMIC_DATA_1);

	avs_enabled = avs_ctl & SPM_1_1_AVS_CTL_AVS_ENABLED;

	/* If AVS is enabled, switch it off during the voltage change */
	if (avs_enabled) {
		avs_ctl &= ~SPM_1_1_AVS_CTL_AVS_ENABLED;
		spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
	}

	/* Kick the state machine back to idle */
	spm_register_write(drv, SPM_REG_RST, 1);

	vctl = FIELD_SET(vctl, SPM_VCTL_VLVL, vlevel);
	data0 = FIELD_SET(data0, SPM_PMIC_DATA_0_VLVL, vlevel);
	data1 = FIELD_SET(data1, SPM_PMIC_DATA_1_MIN_VSEL, volt_sel);
	data1 = FIELD_SET(data1, SPM_PMIC_DATA_1_MAX_VSEL, volt_sel);

	spm_register_write(drv, SPM_REG_VCTL, vctl);
	spm_register_write(drv, SPM_REG_PMIC_DATA_0, data0);
	spm_register_write(drv, SPM_REG_PMIC_DATA_1, data1);

	if (read_poll_timeout_atomic(spm_register_read,
				     sts, sts == vlevel,
				     1, 200, false,
				     drv, SPM_REG_STS1)) {
		dev_err_ratelimited(drv->dev, "timeout setting the voltage (%x %x)!\n", sts, vlevel);
		goto enable_avs;
	}

	if (avs_enabled) {
		unsigned int max_avs = volt_sel;
		unsigned int min_avs = max(max_avs, 4U) - 4;

		avs_ctl = FIELD_SET(avs_ctl, SPM_AVS_CTL_MIN_VLVL, min_avs);
		avs_ctl = FIELD_SET(avs_ctl, SPM_AVS_CTL_MAX_VLVL, max_avs);
		spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
	}

enable_avs:
	if (avs_enabled) {
		avs_ctl |= SPM_1_1_AVS_CTL_AVS_ENABLED;
		spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
	}
}

static int spm_get_cpu(struct device *dev)
{
	int cpu;
	bool found;

	for_each_possible_cpu(cpu) {
		struct device_node *cpu_node, *saw_node;

		cpu_node = of_cpu_device_node_get(cpu);
		if (!cpu_node)
			continue;

		saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
		found = (saw_node == dev->of_node);
		of_node_put(saw_node);
		of_node_put(cpu_node);

		if (found)
			return cpu;
	}

	/* L2 SPM is not bound to any CPU, voltage setting is not supported */

	return -EOPNOTSUPP;
}

static int spm_register_regulator(struct device *dev, struct spm_driver_data *drv)
{
	struct regulator_config config = {
		.dev = dev,
		.driver_data = drv,
	};
	struct regulator_desc *rdesc;
	struct regulator_dev *rdev;
	int ret;
	bool found;

	if (!drv->reg_data->set_vdd)
		return 0;

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

	rdesc->name = "spm";
	rdesc->of_match = of_match_ptr("regulator");
	rdesc->type = REGULATOR_VOLTAGE;
	rdesc->owner = THIS_MODULE;
	rdesc->ops = &spm_reg_ops;

	rdesc->linear_ranges = drv->reg_data->range;
	rdesc->n_linear_ranges = 1;
	rdesc->n_voltages = rdesc->linear_ranges[rdesc->n_linear_ranges - 1].max_sel + 1;
	rdesc->ramp_delay = drv->reg_data->ramp_delay;

	ret = spm_get_cpu(dev);
	if (ret < 0)
		return ret;

	drv->reg_cpu = ret;
	dev_dbg(dev, "SAW2 bound to CPU %d\n", drv->reg_cpu);

	/*
	 * Program initial voltage, otherwise registration will also try
	 * setting the voltage, which might result in undervolting the CPU.
	 */
	drv->volt_sel = DIV_ROUND_UP(drv->reg_data->init_uV - rdesc->min_uV,
				     rdesc->uV_step);
	ret = linear_range_get_selector_high(drv->reg_data->range,
					     drv->reg_data->init_uV,
					     &drv->volt_sel,
					     &found);
	if (ret) {
		dev_err(dev, "Initial uV value out of bounds\n");
		return ret;
	}

	/* Always do the SAW register writes on the corresponding CPU */
	smp_call_function_single(drv->reg_cpu, drv->reg_data->set_vdd, drv, true);

	rdev = devm_regulator_register(dev, rdesc, &config);
	if (IS_ERR(rdev)) {
		dev_err(dev, "failed to register regulator\n");
		return PTR_ERR(rdev);
	}

	return 0;
}

static const struct of_device_id spm_match_table[] = {
	{ .compatible = "qcom,sdm660-gold-saw2-v4.1-l2",
	  .data = &spm_reg_660_gold_l2 },
	{ .compatible = "qcom,sdm660-silver-saw2-v4.1-l2",
	  .data = &spm_reg_660_silver_l2 },
	{ .compatible = "qcom,msm8226-saw2-v2.1-cpu",
	  .data = &spm_reg_8226_cpu },
	{ .compatible = "qcom,msm8909-saw2-v3.0-cpu",
	  .data = &spm_reg_8909_cpu },
	{ .compatible = "qcom,msm8916-saw2-v3.0-cpu",
	  .data = &spm_reg_8916_cpu },
	{ .compatible = "qcom,msm8939-saw2-v3.0-cpu",
	  .data = &spm_reg_8939_cpu },
	{ .compatible = "qcom,msm8974-saw2-v2.1-cpu",
	  .data = &spm_reg_8974_8084_cpu },
	{ .compatible = "qcom,msm8976-gold-saw2-v2.3-l2",
	  .data = &spm_reg_8976_gold_l2 },
	{ .compatible = "qcom,msm8976-silver-saw2-v2.3-l2",
	  .data = &spm_reg_8976_silver_l2 },
	{ .compatible = "qcom,msm8998-gold-saw2-v4.1-l2",
	  .data = &spm_reg_8998_gold_l2 },
	{ .compatible = "qcom,msm8998-silver-saw2-v4.1-l2",
	  .data = &spm_reg_8998_silver_l2 },
	{ .compatible = "qcom,apq8084-saw2-v2.1-cpu",
	  .data = &spm_reg_8974_8084_cpu },
	{ .compatible = "qcom,apq8064-saw2-v1.1-cpu",
	  .data = &spm_reg_8064_cpu },
	{ },
};
MODULE_DEVICE_TABLE(of, spm_match_table);

static int spm_dev_probe(struct platform_device *pdev)
{
	const struct of_device_id *match_id;
	struct spm_driver_data *drv;
	void __iomem *addr;

	drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
	if (!drv)
		return -ENOMEM;

	drv->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(drv->reg_base))
		return PTR_ERR(drv->reg_base);

	match_id = of_match_node(spm_match_table, pdev->dev.of_node);
	if (!match_id)
		return -ENODEV;

	drv->reg_data = match_id->data;
	drv->dev = &pdev->dev;
	platform_set_drvdata(pdev, drv);

	/* Write the SPM sequences first.. */
	addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
	__iowrite32_copy(addr, drv->reg_data->seq,
			ARRAY_SIZE(drv->reg_data->seq) / 4);

	/*
	 * ..and then the control registers.
	 * On some SoC if the control registers are written first and if the
	 * CPU was held in reset, the reset signal could trigger the SPM state
	 * machine, before the sequences are completely written.
	 */
	spm_register_write(drv, SPM_REG_AVS_CTL, drv->reg_data->avs_ctl);
	spm_register_write(drv, SPM_REG_AVS_LIMIT, drv->reg_data->avs_limit);
	spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
	spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
	spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
	spm_register_write(drv, SPM_REG_PMIC_DATA_0,
				drv->reg_data->pmic_data[0]);
	spm_register_write(drv, SPM_REG_PMIC_DATA_1,
				drv->reg_data->pmic_data[1]);

	/* Set up Standby as the default low power mode */
	if (drv->reg_data->reg_offset[SPM_REG_SPM_CTL])
		spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);

	if (IS_ENABLED(CONFIG_REGULATOR))
		return spm_register_regulator(&pdev->dev, drv);

	return 0;
}

static struct platform_driver spm_driver = {
	.probe = spm_dev_probe,
	.driver = {
		.name = "qcom_spm",
		.of_match_table = spm_match_table,
	},
};

static int __init qcom_spm_init(void)
{
	return platform_driver_register(&spm_driver);
}
arch_initcall(qcom_spm_init);

MODULE_DESCRIPTION("Qualcomm Subsystem Power Manager (SPM)");
MODULE_LICENSE("GPL v2");