regulator: Add support for Richtek RT5739 voltage regulator

The RT5739 is a step-down switching voltage regulator that supports
output voltage ragne from 300mV to 1300mV with the wide input supply
voltage range from 2.5V to 5.5V.

Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/1676599618-24819-3-git-send-email-cy_huang@richtek.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: ChiYuan Huang

drivers/regulator/Kconfig

@@ -1120,6 +1120,19 @@ config REGULATOR_RT5190A
 	  buck converters, 1 LDO, mute AC OFF depop function, with the general
 	  I2C control interface.
 
+config REGULATOR_RT5739
+	tristate "Rcihtek RT5739 Regulator"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This adds support for voltage regulator in Richtek RT5739.
+	  It's a step-down switching voltage regulator. Using a proprietary
+	  architecture with synchronous rectification, it is capable of
+	  delivering 3.5A continuously at over 80% efficiency.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rt5739.
+
 config REGULATOR_RT5759
 	tristate "Richtek RT5759 Regulator"
 	depends on I2C

drivers/regulator/Makefile

@@ -134,6 +134,7 @@ obj-$(CONFIG_REGULATOR_RT4831)	+= rt4831-regulator.o
 obj-$(CONFIG_REGULATOR_RT5033)	+= rt5033-regulator.o
 obj-$(CONFIG_REGULATOR_RT5120)	+= rt5120-regulator.o
 obj-$(CONFIG_REGULATOR_RT5190A) += rt5190a-regulator.o
+obj-$(CONFIG_REGULATOR_RT5739)	+= rt5739.o
 obj-$(CONFIG_REGULATOR_RT5759)	+= rt5759-regulator.o
 obj-$(CONFIG_REGULATOR_RT6160)	+= rt6160-regulator.o
 obj-$(CONFIG_REGULATOR_RT6190)	+= rt6190-regulator.o

drivers/regulator/rt5739.c

@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Device driver for RT5739 regulator
+ *
+ * Copyright (C) 2023 Richtek Technology Corp.
+ *
+ * Author: ChiYuan Huang <cy_huang@richtek.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define RT5739_AUTO_MODE	0
+#define RT5739_FPWM_MODE	1
+
+#define RT5739_REG_NSEL0	0x00
+#define RT5739_REG_NSEL1	0x01
+#define RT5739_REG_CNTL1	0x02
+#define RT5739_REG_ID1		0x03
+#define RT5739_REG_CNTL2	0x06
+#define RT5739_REG_CNTL4	0x08
+
+#define RT5739_VSEL_MASK	GENMASK(7, 0)
+#define RT5739_MODEVSEL1_MASK	BIT(1)
+#define RT5739_MODEVSEL0_MASK	BIT(0)
+#define RT5739_VID_MASK		GENMASK(7, 5)
+#define RT5739_ACTD_MASK	BIT(7)
+#define RT5739_ENVSEL1_MASK	BIT(1)
+#define RT5739_ENVSEL0_MASK	BIT(0)
+
+#define RT5739_VOLT_MINUV	300000
+#define RT5739_VOLT_MAXUV	1300000
+#define RT5739_VOLT_STPUV	5000
+#define RT5739_N_VOLTS		201
+#define RT5739_I2CRDY_TIMEUS	1000
+
+static int rt5739_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int mask, val;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		mask = RT5739_MODEVSEL0_MASK;
+	else
+		mask = RT5739_MODEVSEL1_MASK;
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		val = mask;
+		break;
+	case REGULATOR_MODE_NORMAL:
+		val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(regmap, RT5739_REG_CNTL1, mask, val);
+}
+
+static unsigned int rt5739_get_mode(struct regulator_dev *rdev)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int mask, val;
+	int ret;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		mask = RT5739_MODEVSEL0_MASK;
+	else
+		mask = RT5739_MODEVSEL1_MASK;
+
+	ret = regmap_read(regmap, RT5739_REG_CNTL1, &val);
+	if (ret)
+		return REGULATOR_MODE_INVALID;
+
+	if (val & mask)
+		return REGULATOR_MODE_FAST;
+
+	return REGULATOR_MODE_NORMAL;
+}
+
+static int rt5739_set_suspend_voltage(struct regulator_dev *rdev, int uV)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int reg, vsel;
+
+	if (uV < RT5739_VOLT_MINUV || uV > RT5739_VOLT_MAXUV)
+		return -EINVAL;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		reg = RT5739_REG_NSEL1;
+	else
+		reg = RT5739_REG_NSEL0;
+
+	vsel = (uV - RT5739_VOLT_MINUV) / RT5739_VOLT_STPUV;
+	return regmap_write(regmap, reg, vsel);
+}
+
+static int rt5739_set_suspend_enable(struct regulator_dev *rdev)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int mask;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		mask = RT5739_ENVSEL1_MASK;
+	else
+		mask = RT5739_ENVSEL0_MASK;
+
+	return regmap_update_bits(regmap, desc->enable_reg, mask, mask);
+}
+
+static int rt5739_set_suspend_disable(struct regulator_dev *rdev)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int mask;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		mask = RT5739_ENVSEL1_MASK;
+	else
+		mask = RT5739_ENVSEL0_MASK;
+
+	return regmap_update_bits(regmap, desc->enable_reg, mask, 0);
+}
+
+static int rt5739_set_suspend_mode(struct regulator_dev *rdev,
+				   unsigned int mode)
+{
+	const struct regulator_desc *desc = rdev->desc;
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int mask, val;
+
+	if (desc->vsel_reg == RT5739_REG_NSEL0)
+		mask = RT5739_MODEVSEL1_MASK;
+	else
+		mask = RT5739_MODEVSEL0_MASK;
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		val = mask;
+		break;
+	case REGULATOR_MODE_NORMAL:
+		val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(regmap, RT5739_REG_CNTL1, mask, val);
+}
+
+static const struct regulator_ops rt5739_regulator_ops = {
+	.list_voltage = regulator_list_voltage_linear,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.enable	= regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.set_active_discharge = regulator_set_active_discharge_regmap,
+	.set_mode = rt5739_set_mode,
+	.get_mode = rt5739_get_mode,
+	.set_suspend_voltage = rt5739_set_suspend_voltage,
+	.set_suspend_enable = rt5739_set_suspend_enable,
+	.set_suspend_disable = rt5739_set_suspend_disable,
+	.set_suspend_mode = rt5739_set_suspend_mode,
+};
+
+static unsigned int rt5739_of_map_mode(unsigned int mode)
+{
+	switch (mode) {
+	case RT5739_AUTO_MODE:
+		return REGULATOR_MODE_NORMAL;
+	case RT5739_FPWM_MODE:
+		return REGULATOR_MODE_FAST;
+	default:
+		return REGULATOR_MODE_INVALID;
+	}
+}
+
+static void rt5739_init_regulator_desc(struct regulator_desc *desc,
+				       bool vsel_active_high)
+{
+	/* Fixed */
+	desc->name = "rt5739-regulator";
+	desc->owner = THIS_MODULE;
+	desc->ops = &rt5739_regulator_ops;
+	desc->n_voltages = RT5739_N_VOLTS;
+	desc->min_uV = RT5739_VOLT_MINUV;
+	desc->uV_step = RT5739_VOLT_STPUV;
+	desc->vsel_mask = RT5739_VSEL_MASK;
+	desc->enable_reg = RT5739_REG_CNTL2;
+	desc->active_discharge_reg = RT5739_REG_CNTL1;
+	desc->active_discharge_mask = RT5739_ACTD_MASK;
+	desc->active_discharge_on = RT5739_ACTD_MASK;
+	desc->of_map_mode = rt5739_of_map_mode;
+
+	/* Assigned by vsel level */
+	if (vsel_active_high) {
+		desc->vsel_reg = RT5739_REG_NSEL1;
+		desc->enable_mask = RT5739_ENVSEL1_MASK;
+	} else {
+		desc->vsel_reg = RT5739_REG_NSEL0;
+		desc->enable_mask = RT5739_ENVSEL0_MASK;
+	}
+}
+
+static const struct regmap_config rt5739_regmap_config = {
+	.name = "rt5739",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RT5739_REG_CNTL4,
+};
+
+static int rt5739_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct regulator_desc *desc;
+	struct regmap *regmap;
+	struct gpio_desc *enable_gpio;
+	struct regulator_config cfg = {};
+	struct regulator_dev *rdev;
+	bool vsel_acth;
+	unsigned int vid;
+	int ret;
+
+	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(enable_gpio))
+		return dev_err_probe(dev, PTR_ERR(enable_gpio), "Failed to get 'enable' gpio\n");
+	else if (enable_gpio)
+		usleep_range(RT5739_I2CRDY_TIMEUS, RT5739_I2CRDY_TIMEUS + 1000);
+
+	regmap = devm_regmap_init_i2c(i2c, &rt5739_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to init regmap\n");
+
+	ret = regmap_read(regmap, RT5739_REG_ID1, &vid);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to read VID\n");
+
+	/* RT5739: (VID & MASK) must be 0 */
+	if (vid & RT5739_VID_MASK)
+		return dev_err_probe(dev, -ENODEV, "Incorrect VID (0x%02x)\n", vid);
+
+	vsel_acth = device_property_read_bool(dev, "richtek,vsel-active-high");
+
+	rt5739_init_regulator_desc(desc, vsel_acth);
+
+	cfg.dev = dev;
+	cfg.of_node = dev_of_node(dev);
+	cfg.init_data = of_get_regulator_init_data(dev, dev_of_node(dev), desc);
+	rdev = devm_regulator_register(dev, desc, &cfg);
+	if (IS_ERR(rdev))
+		return dev_err_probe(dev, PTR_ERR(rdev), "Failed to register regulator\n");
+
+	return 0;
+}
+
+static const struct of_device_id rt5739_device_table[] = {
+	{ .compatible = "richtek,rt5739" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rt5739_device_table);
+
+static struct i2c_driver rt5739_driver = {
+	.driver = {
+		.name = "rt5739",
+		.of_match_table = rt5739_device_table,
+	},
+	.probe_new = rt5739_probe,
+};
+module_i2c_driver(rt5739_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_DESCRIPTION("Richtek RT5739 regulator driver");
+MODULE_LICENSE("GPL");