qcom-labibb-regulator.c

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2020, The Linux Foundation. All rights reserved.

#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

#define REG_PERPH_TYPE                  0x04

#define QCOM_LAB_TYPE			0x24
#define QCOM_IBB_TYPE			0x20

#define PMI8998_LAB_REG_BASE		0xde00
#define PMI8998_IBB_REG_BASE		0xdc00

#define REG_LABIBB_STATUS1		0x08

#define REG_LABIBB_VOLTAGE		0x41
 #define LABIBB_VOLTAGE_OVERRIDE_EN	BIT(7)
 #define LAB_VOLTAGE_SET_MASK		GENMASK(3, 0)
 #define IBB_VOLTAGE_SET_MASK		GENMASK(5, 0)

#define REG_LABIBB_ENABLE_CTL		0x46
#define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
#define LABIBB_CONTROL_ENABLE		BIT(7)

#define REG_LABIBB_PD_CTL		0x47
 #define LAB_PD_CTL_MASK		GENMASK(1, 0)
 #define IBB_PD_CTL_MASK		(BIT(0) | BIT(7))
 #define LAB_PD_CTL_STRONG_PULL		BIT(0)
 #define IBB_PD_CTL_HALF_STRENGTH	BIT(0)
 #define IBB_PD_CTL_EN			BIT(7)

#define REG_LABIBB_CURRENT_LIMIT	0x4b
 #define LAB_CURRENT_LIMIT_MASK		GENMASK(2, 0)
 #define IBB_CURRENT_LIMIT_MASK		GENMASK(4, 0)
 #define LAB_CURRENT_LIMIT_OVERRIDE_EN	BIT(3)
 #define LABIBB_CURRENT_LIMIT_EN	BIT(7)

#define REG_IBB_PWRUP_PWRDN_CTL_1	0x58
 #define IBB_CTL_1_DISCHARGE_EN		BIT(2)

#define REG_LABIBB_SOFT_START_CTL	0x5f
#define REG_LABIBB_SEC_ACCESS		0xd0
 #define LABIBB_SEC_UNLOCK_CODE		0xa5

#define LAB_ENABLE_CTL_MASK		BIT(7)
#define IBB_ENABLE_CTL_MASK		(BIT(7) | BIT(6))

#define LABIBB_OFF_ON_DELAY		1000
#define LAB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 2)
#define IBB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 10)
#define LABIBB_POLL_ENABLED_TIME	1000

struct labibb_current_limits {
	u32				uA_min;
	u32				uA_step;
	u8				ovr_val;
};

struct labibb_regulator {
	struct regulator_desc		desc;
	struct device			*dev;
	struct regmap			*regmap;
	struct regulator_dev		*rdev;
	struct labibb_current_limits	uA_limits;
	u16				base;
	u8				type;
	u8				dischg_sel;
	u8				soft_start_sel;
};

struct labibb_regulator_data {
	const char			*name;
	u8				type;
	u16				base;
	const struct regulator_desc	*desc;
};

static int qcom_labibb_set_current_limit(struct regulator_dev *rdev,
					 int min_uA, int max_uA)
{
	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
	struct regulator_desc *desc = &vreg->desc;
	struct labibb_current_limits *lim = &vreg->uA_limits;
	u32 mask, val;
	int i, ret, sel = -1;

	if (min_uA < lim->uA_min || max_uA < lim->uA_min)
		return -EINVAL;

	for (i = 0; i < desc->n_current_limits; i++) {
		int uA_limit = (lim->uA_step * i) + lim->uA_min;

		if (max_uA >= uA_limit && min_uA <= uA_limit)
			sel = i;
	}
	if (sel < 0)
		return -EINVAL;

	/* Current limit setting needs secure access */
	ret = regmap_write(vreg->regmap, vreg->base + REG_LABIBB_SEC_ACCESS,
			   LABIBB_SEC_UNLOCK_CODE);
	if (ret)
		return ret;

	mask = desc->csel_mask | lim->ovr_val;
	mask |= LABIBB_CURRENT_LIMIT_EN;
	val = (u32)sel | lim->ovr_val;
	val |= LABIBB_CURRENT_LIMIT_EN;

	return regmap_update_bits(vreg->regmap, desc->csel_reg, mask, val);
}

static int qcom_labibb_get_current_limit(struct regulator_dev *rdev)
{
	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
	struct regulator_desc *desc = &vreg->desc;
	struct labibb_current_limits *lim = &vreg->uA_limits;
	unsigned int cur_step;
	int ret;

	ret = regmap_read(vreg->regmap, desc->csel_reg, &cur_step);
	if (ret)
		return ret;
	cur_step &= desc->csel_mask;

	return (cur_step * lim->uA_step) + lim->uA_min;
}

static int qcom_labibb_set_soft_start(struct regulator_dev *rdev)
{
	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
	u32 val = 0;

	if (vreg->type == QCOM_IBB_TYPE)
		val = vreg->dischg_sel;
	else
		val = vreg->soft_start_sel;

	return regmap_write(rdev->regmap, rdev->desc->soft_start_reg, val);
}

static int qcom_labibb_get_table_sel(const int *table, int sz, u32 value)
{
	int i;

	for (i = 0; i < sz; i++)
		if (table[i] == value)
			return i;
	return -EINVAL;
}

/* IBB discharge resistor values in KOhms */
static const int dischg_resistor_values[] = { 300, 64, 32, 16 };

/* Soft start time in microseconds */
static const int soft_start_values[] = { 200, 400, 600, 800 };

static int qcom_labibb_of_parse_cb(struct device_node *np,
				   const struct regulator_desc *desc,
				   struct regulator_config *config)
{
	struct labibb_regulator *vreg = config->driver_data;
	u32 dischg_kohms, soft_start_time;
	int ret;

	ret = of_property_read_u32(np, "qcom,discharge-resistor-kohms",
				       &dischg_kohms);
	if (ret)
		dischg_kohms = 300;

	ret = qcom_labibb_get_table_sel(dischg_resistor_values,
					ARRAY_SIZE(dischg_resistor_values),
					dischg_kohms);
	if (ret < 0)
		return ret;
	vreg->dischg_sel = (u8)ret;

	ret = of_property_read_u32(np, "qcom,soft-start-us",
				   &soft_start_time);
	if (ret)
		soft_start_time = 200;

	ret = qcom_labibb_get_table_sel(soft_start_values,
					ARRAY_SIZE(soft_start_values),
					soft_start_time);
	if (ret < 0)
		return ret;
	vreg->soft_start_sel = (u8)ret;

	return 0;
}

static const struct regulator_ops qcom_labibb_ops = {
	.enable			= regulator_enable_regmap,
	.disable		= regulator_disable_regmap,
	.is_enabled		= regulator_is_enabled_regmap,
	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
	.list_voltage		= regulator_list_voltage_linear,
	.map_voltage		= regulator_map_voltage_linear,
	.set_active_discharge	= regulator_set_active_discharge_regmap,
	.set_pull_down		= regulator_set_pull_down_regmap,
	.set_current_limit	= qcom_labibb_set_current_limit,
	.get_current_limit	= qcom_labibb_get_current_limit,
	.set_soft_start		= qcom_labibb_set_soft_start,
};

static const struct regulator_desc pmi8998_lab_desc = {
	.enable_mask		= LAB_ENABLE_CTL_MASK,
	.enable_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_ENABLE_CTL),
	.enable_val		= LABIBB_CONTROL_ENABLE,
	.enable_time		= LAB_ENABLE_TIME,
	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
	.soft_start_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
	.pull_down_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_PD_CTL),
	.pull_down_mask		= LAB_PD_CTL_MASK,
	.pull_down_val_on	= LAB_PD_CTL_STRONG_PULL,
	.vsel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
	.vsel_mask		= LAB_VOLTAGE_SET_MASK,
	.apply_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
	.csel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
	.csel_mask		= LAB_CURRENT_LIMIT_MASK,
	.n_current_limits	= 8,
	.off_on_delay		= LABIBB_OFF_ON_DELAY,
	.owner			= THIS_MODULE,
	.type			= REGULATOR_VOLTAGE,
	.min_uV			= 4600000,
	.uV_step		= 100000,
	.n_voltages		= 16,
	.ops			= &qcom_labibb_ops,
	.of_parse_cb		= qcom_labibb_of_parse_cb,
};

static const struct regulator_desc pmi8998_ibb_desc = {
	.enable_mask		= IBB_ENABLE_CTL_MASK,
	.enable_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_ENABLE_CTL),
	.enable_val		= LABIBB_CONTROL_ENABLE,
	.enable_time		= IBB_ENABLE_TIME,
	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
	.soft_start_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
	.active_discharge_off	= 0,
	.active_discharge_on	= IBB_CTL_1_DISCHARGE_EN,
	.active_discharge_mask	= IBB_CTL_1_DISCHARGE_EN,
	.active_discharge_reg	= (PMI8998_IBB_REG_BASE + REG_IBB_PWRUP_PWRDN_CTL_1),
	.pull_down_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_PD_CTL),
	.pull_down_mask		= IBB_PD_CTL_MASK,
	.pull_down_val_on	= IBB_PD_CTL_HALF_STRENGTH | IBB_PD_CTL_EN,
	.vsel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
	.vsel_mask		= IBB_VOLTAGE_SET_MASK,
	.apply_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
	.csel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
	.csel_mask		= IBB_CURRENT_LIMIT_MASK,
	.n_current_limits	= 32,
	.off_on_delay		= LABIBB_OFF_ON_DELAY,
	.owner			= THIS_MODULE,
	.type			= REGULATOR_VOLTAGE,
	.min_uV			= 1400000,
	.uV_step		= 100000,
	.n_voltages		= 64,
	.ops			= &qcom_labibb_ops,
	.of_parse_cb		= qcom_labibb_of_parse_cb,
};

static const struct labibb_regulator_data pmi8998_labibb_data[] = {
	{"lab", QCOM_LAB_TYPE, PMI8998_LAB_REG_BASE, &pmi8998_lab_desc},
	{"ibb", QCOM_IBB_TYPE, PMI8998_IBB_REG_BASE, &pmi8998_ibb_desc},
	{ },
};

static const struct of_device_id qcom_labibb_match[] = {
	{ .compatible = "qcom,pmi8998-lab-ibb", .data = &pmi8998_labibb_data},
	{ },
};
MODULE_DEVICE_TABLE(of, qcom_labibb_match);

static int qcom_labibb_regulator_probe(struct platform_device *pdev)
{
	struct labibb_regulator *vreg;
	struct device *dev = &pdev->dev;
	struct regulator_config cfg = {};

	const struct of_device_id *match;
	const struct labibb_regulator_data *reg_data;
	struct regmap *reg_regmap;
	unsigned int type;
	int ret;

	reg_regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!reg_regmap) {
		dev_err(&pdev->dev, "Couldn't get parent's regmap\n");
		return -ENODEV;
	}

	match = of_match_device(qcom_labibb_match, &pdev->dev);
	if (!match)
		return -ENODEV;

	for (reg_data = match->data; reg_data->name; reg_data++) {

		/* Validate if the type of regulator is indeed
		 * what's mentioned in DT.
		 */
		ret = regmap_read(reg_regmap, reg_data->base + REG_PERPH_TYPE,
				  &type);
		if (ret < 0) {
			dev_err(dev,
				"Peripheral type read failed ret=%d\n",
				ret);
			return -EINVAL;
		}

		if (WARN_ON((type != QCOM_LAB_TYPE) && (type != QCOM_IBB_TYPE)) ||
		    WARN_ON(type != reg_data->type))
			return -EINVAL;

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

		vreg->regmap = reg_regmap;
		vreg->dev = dev;
		vreg->base = reg_data->base;
		vreg->type = reg_data->type;

		switch (vreg->type) {
		case QCOM_LAB_TYPE:
			/* LAB Limits: 200-1600mA */
			vreg->uA_limits.uA_min  = 200000;
			vreg->uA_limits.uA_step = 200000;
			vreg->uA_limits.ovr_val = LAB_CURRENT_LIMIT_OVERRIDE_EN;
			break;
		case QCOM_IBB_TYPE:
			/* IBB Limits: 0-1550mA */
			vreg->uA_limits.uA_min  = 0;
			vreg->uA_limits.uA_step = 50000;
			vreg->uA_limits.ovr_val = 0; /* No override bit */
			break;
		default:
			return -EINVAL;
		}

		memcpy(&vreg->desc, reg_data->desc, sizeof(vreg->desc));
		vreg->desc.of_match = reg_data->name;
		vreg->desc.name = reg_data->name;

		cfg.dev = vreg->dev;
		cfg.driver_data = vreg;
		cfg.regmap = vreg->regmap;

		vreg->rdev = devm_regulator_register(vreg->dev, &vreg->desc,
							&cfg);

		if (IS_ERR(vreg->rdev)) {
			dev_err(dev, "qcom_labibb: error registering %s : %d\n",
					reg_data->name, ret);
			return PTR_ERR(vreg->rdev);
		}
	}

	return 0;
}

static struct platform_driver qcom_labibb_regulator_driver = {
	.driver	= {
		.name = "qcom-lab-ibb-regulator",
		.of_match_table	= qcom_labibb_match,
	},
	.probe = qcom_labibb_regulator_probe,
};
module_platform_driver(qcom_labibb_regulator_driver);

MODULE_DESCRIPTION("Qualcomm labibb driver");
MODULE_AUTHOR("Nisha Kumari <nishakumari@codeaurora.org>");
MODULE_AUTHOR("Sumit Semwal <sumit.semwal@linaro.org>");
MODULE_LICENSE("GPL v2");