regulator: rt4831: Adds support for Richtek RT4831 DSV regulator

Adds support for Richtek RT4831 DSV Regulator

Signed-off-by: ChiYuan Huang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/Kconfig

···
 	  This adds support for voltage regulators in Richtek RT4801 Display Bias IC.
 	  The device supports two regulators (DSVP/DSVN).
 
+config REGULATOR_RT4831
+	tristate "Richtek RT4831 DSV Regulators"
+	depends on MFD_RT4831
+	help
+	  This adds support for voltage regulators in Richtek RT4831.
+	  There are three regulators (VLCM/DSVP/DSVN).
+	  VLCM is a virtual voltage input for DSVP/DSVN inside IC.
+	  And DSVP/DSVN is the real Vout range from 4V to 6.5V.
+	  It's common used to provide the power for the display panel.
+
 config REGULATOR_RT5033
 	tristate "Richtek RT5033 Regulators"
 	depends on MFD_RT5033

drivers/regulator/Makefile

···
 obj-$(CONFIG_REGULATOR_RN5T618) += rn5t618-regulator.o
 obj-$(CONFIG_REGULATOR_ROHM)	+= rohm-regulator.o
 obj-$(CONFIG_REGULATOR_RT4801)	+= rt4801-regulator.o
+obj-$(CONFIG_REGULATOR_RT4831)	+= rt4831-regulator.o
 obj-$(CONFIG_REGULATOR_RT5033)	+= rt5033-regulator.o
 obj-$(CONFIG_REGULATOR_RTMV20)	+= rtmv20-regulator.o
 obj-$(CONFIG_REGULATOR_S2MPA01) += s2mpa01.o

drivers/regulator/rt4831-regulator.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/driver.h>
+
+enum {
+	DSV_OUT_VLCM = 0,
+	DSV_OUT_VPOS,
+	DSV_OUT_VNEG,
+	DSV_OUT_MAX
+};
+
+#define RT4831_REG_DSVEN	0x09
+#define RT4831_REG_VLCM		0x0c
+#define RT4831_REG_VPOS		0x0d
+#define RT4831_REG_VNEG		0x0e
+#define RT4831_REG_FLAGS	0x0f
+
+#define RT4831_VOLT_MASK	GENMASK(5, 0)
+#define RT4831_DSVMODE_SHIFT	5
+#define RT4831_DSVMODE_MASK	GENMASK(7, 5)
+#define RT4831_POSADEN_MASK	BIT(4)
+#define RT4831_NEGADEN_MASK	BIT(3)
+#define RT4831_POSEN_MASK	BIT(2)
+#define RT4831_NEGEN_MASK	BIT(1)
+
+#define RT4831_OTP_MASK		BIT(6)
+#define RT4831_LCMOVP_MASK	BIT(5)
+#define RT4831_VPOSSCP_MASK	BIT(3)
+#define RT4831_VNEGSCP_MASK	BIT(2)
+
+#define DSV_MODE_NORMAL		(0x4 << RT4831_DSVMODE_SHIFT)
+#define DSV_MODE_BYPASS		(0x6 << RT4831_DSVMODE_SHIFT)
+#define STEP_UV			50000
+#define VLCM_MIN_UV		4000000
+#define VLCM_MAX_UV		7150000
+#define VLCM_N_VOLTAGES		((VLCM_MAX_UV - VLCM_MIN_UV) / STEP_UV + 1)
+#define VPN_MIN_UV		4000000
+#define VPN_MAX_UV		6500000
+#define VPN_N_VOLTAGES		((VPN_MAX_UV - VPN_MIN_UV) / STEP_UV + 1)
+
+static int rt4831_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
+{
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	int rid = rdev_get_id(rdev);
+	unsigned int val, events = 0;
+	int ret;
+
+	ret = regmap_read(regmap, RT4831_REG_FLAGS, &val);
+	if (ret)
+		return ret;
+
+	if (val & RT4831_OTP_MASK)
+		events |= REGULATOR_ERROR_OVER_TEMP;
+
+	if (rid == DSV_OUT_VLCM && (val & RT4831_LCMOVP_MASK))
+		events |= REGULATOR_ERROR_OVER_CURRENT;
+
+	if (rid == DSV_OUT_VPOS && (val & RT4831_VPOSSCP_MASK))
+		events |= REGULATOR_ERROR_OVER_CURRENT;
+
+	if (rid == DSV_OUT_VNEG && (val & RT4831_VNEGSCP_MASK))
+		events |= REGULATOR_ERROR_OVER_CURRENT;
+
+	*flags = events;
+	return 0;
+}
+
+static const struct regulator_ops rt4831_dsvlcm_ops = {
+	.list_voltage = regulator_list_voltage_linear,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_bypass = regulator_set_bypass_regmap,
+	.get_bypass = regulator_get_bypass_regmap,
+	.get_error_flags = rt4831_get_error_flags,
+};
+
+static const struct regulator_ops rt4831_dsvpn_ops = {
+	.list_voltage = regulator_list_voltage_linear,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_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,
+	.get_error_flags = rt4831_get_error_flags,
+};
+
+static const struct regulator_desc rt4831_regulator_descs[] = {
+	{
+		.name = "DSVLCM",
+		.ops = &rt4831_dsvlcm_ops,
+		.of_match = of_match_ptr("DSVLCM"),
+		.regulators_node = of_match_ptr("regulators"),
+		.type = REGULATOR_VOLTAGE,
+		.id = DSV_OUT_VLCM,
+		.n_voltages = VLCM_N_VOLTAGES,
+		.min_uV = VLCM_MIN_UV,
+		.uV_step = STEP_UV,
+		.vsel_reg = RT4831_REG_VLCM,
+		.vsel_mask = RT4831_VOLT_MASK,
+		.bypass_reg = RT4831_REG_DSVEN,
+		.bypass_val_on = DSV_MODE_BYPASS,
+		.bypass_val_off = DSV_MODE_NORMAL,
+	},
+	{
+		.name = "DSVP",
+		.ops = &rt4831_dsvpn_ops,
+		.of_match = of_match_ptr("DSVP"),
+		.regulators_node = of_match_ptr("regulators"),
+		.type = REGULATOR_VOLTAGE,
+		.id = DSV_OUT_VPOS,
+		.n_voltages = VPN_N_VOLTAGES,
+		.min_uV = VPN_MIN_UV,
+		.uV_step = STEP_UV,
+		.vsel_reg = RT4831_REG_VPOS,
+		.vsel_mask = RT4831_VOLT_MASK,
+		.enable_reg = RT4831_REG_DSVEN,
+		.enable_mask = RT4831_POSEN_MASK,
+		.active_discharge_reg = RT4831_REG_DSVEN,
+		.active_discharge_mask = RT4831_POSADEN_MASK,
+	},
+	{
+		.name = "DSVN",
+		.ops = &rt4831_dsvpn_ops,
+		.of_match = of_match_ptr("DSVN"),
+		.regulators_node = of_match_ptr("regulators"),
+		.type = REGULATOR_VOLTAGE,
+		.id = DSV_OUT_VNEG,
+		.n_voltages = VPN_N_VOLTAGES,
+		.min_uV = VPN_MIN_UV,
+		.uV_step = STEP_UV,
+		.vsel_reg = RT4831_REG_VNEG,
+		.vsel_mask = RT4831_VOLT_MASK,
+		.enable_reg = RT4831_REG_DSVEN,
+		.enable_mask = RT4831_NEGEN_MASK,
+		.active_discharge_reg = RT4831_REG_DSVEN,
+		.active_discharge_mask = RT4831_NEGADEN_MASK,
+	}
+};
+
+static int rt4831_regulator_probe(struct platform_device *pdev)
+{
+	struct regmap *regmap;
+	struct regulator_dev *rdev;
+	struct regulator_config config = {};
+	int i, ret;
+
+	regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (IS_ERR(regmap)) {
+		dev_err(&pdev->dev, "Failed to init regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	/* Configure DSV mode to normal by default */
+	ret = regmap_update_bits(regmap, RT4831_REG_DSVEN, RT4831_DSVMODE_MASK, DSV_MODE_NORMAL);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to configure dsv mode to normal\n");
+		return ret;
+	}
+
+	config.dev = pdev->dev.parent;
+	config.regmap = regmap;
+
+	for (i = 0; i < DSV_OUT_MAX; i++) {
+		rdev = devm_regulator_register(&pdev->dev, rt4831_regulator_descs + i, &config);
+		if (IS_ERR(rdev)) {
+			dev_err(&pdev->dev, "Failed to register %d regulator\n", i);
+			return PTR_ERR(rdev);
+		}
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id rt4831_regulator_match[] = {
+	{ "rt4831-regulator", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, rt4831_regulator_match);
+
+static struct platform_driver rt4831_regulator_driver = {
+	.driver = {
+		.name = "rt4831-regulator",
+	},
+	.id_table = rt4831_regulator_match,
+	.probe = rt4831_regulator_probe,
+};
+module_platform_driver(rt4831_regulator_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <[e-mail]>");
+MODULE_LICENSE("GPL v2");