From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Rock Shen <rock_shen@asus.com>
Date: Tue, 27 Apr 2021 11:13:25 +0800
Subject: regulator: add fan53200 regulator driver for Tinkerboard-2

1. Add fan53200 regulator support for vdd_cpu_b & vdd_gpu
2. By Tinker2 HW design, Vsel gpio pin polarity was reversed, switch
   sleep_reg & vol_reg at fan53200_voltages_setup_fairchild
3. Use vsel0 as suspend source, vsel1 as normal source

- rpardini: hammered .probe and probe_type = PROBE_PREFER_ASYNCHRONOUS to
  work on 6.6.y, after https://lore.kernel.org/all/20230505220218.1239542-1-u.kleine-koenig@pengutronix.de/

Signed-off-by: Rock Shen <rock_shen@asus.com>
Signed-off-by: Ricardo Pardini <ricardo@pardini.net>
---
 arch/arm64/configs/defconfig |   1 +
 drivers/regulator/Kconfig    |  11 +
 drivers/regulator/Makefile   |   1 +
 drivers/regulator/fan53200.c | 520 ++++++++++
 4 files changed, 533 insertions(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 111111111111..222222222222 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -784,6 +784,7 @@ CONFIG_REGULATOR_BD9571MWV=y
 CONFIG_REGULATOR_CROS_EC=y
 CONFIG_REGULATOR_DA9211=m
 CONFIG_REGULATOR_FAN53555=y
+CONFIG_REGULATOR_FAN53200=y
 CONFIG_REGULATOR_GPIO=y
 CONFIG_REGULATOR_HI6421V530=y
 CONFIG_REGULATOR_HI655X=y
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 111111111111..222222222222 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -421,6 +421,17 @@ config REGULATOR_FAN53880
 	  (PMIC), it is controlled by I2C and provides one BUCK, one BOOST
 	  and four LDO outputs.
 
+config REGULATOR_FAN53200
+	tristate "Fairchild FAN53200 Regulator"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver supports Fairchild FAN53200 Digitally Programmable
+	  TinyBuck Regulator. The FAN53200 is a step-down switching voltage
+	  regulator that delivers a digitally programmable output from an
+	  input voltage supply of 2.5V to 5.5V. The output voltage is
+	  programmed through an I2C interface.
+
 config REGULATOR_GPIO
 	tristate "GPIO regulator support"
 	depends on GPIOLIB || COMPILE_TEST
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 111111111111..222222222222 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_REGULATOR_DBX500_PRCMU) += dbx500-prcmu.o
 obj-$(CONFIG_REGULATOR_DB8500_PRCMU) += db8500-prcmu.o
 obj-$(CONFIG_REGULATOR_FAN53555) += fan53555.o
 obj-$(CONFIG_REGULATOR_FAN53880) += fan53880.o
+obj-$(CONFIG_REGULATOR_FAN53555) += fan53200.o
 obj-$(CONFIG_REGULATOR_GPIO) += gpio-regulator.o
 obj-$(CONFIG_REGULATOR_HI6421) += hi6421-regulator.o
 obj-$(CONFIG_REGULATOR_HI6421V530) += hi6421v530-regulator.o
diff --git a/drivers/regulator/fan53200.c b/drivers/regulator/fan53200.c
new file mode 100644
index 000000000000..111111111111
--- /dev/null
+++ b/drivers/regulator/fan53200.c
@@ -0,0 +1,520 @@
+/*
+ * FAN53200 Fairchild Digitally Programmable TinyBuck Regulator Driver.
+ *
+ * Supported Part Numbers:
+ * FAN53200UC35X/44X
+ *
+ * Copyright (c) 2021 ASUSTeK Computer Inc.
+ * Rock Shen <rock_shen@asus.com>
+ *
+ * This package is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/of_device.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+/* Voltage setting */
+#define FAN53200_VSEL0		0x00
+#define FAN53200_VSEL1		0x01
+
+/* Control register */
+#define FAN53200_CONTROL	0x02
+/* IC Type */
+#define FAN53200_ID1		0x03
+/* IC mask version */
+#define FAN53200_ID2		0x04
+
+/* VSEL bit definitions */
+#define VSEL_BUCK_EN	(1 << 7)
+#define VSEL_MODE		(1 << 6)
+#define VSEL_NSEL_MASK	0x3F
+/* Chip ID and Verison */
+#define DIE_ID		0x0F	/* ID1 */
+#define DIE_REV		0x0F	/* ID2 */
+/* Control bit definitions */
+#define CTL_OUTPUT_DISCHG	(1 << 7)
+#define CTL_SLEW_MASK		(0x7 << 4)
+#define CTL_SLEW_SHIFT		4
+#define CTL_RESET			(1 << 2)
+
+#define TCS_VSEL_NSEL_MASK	0x7f
+#define TCS_VSEL0_MODE		(1 << 7)
+#define TCS_VSEL1_MODE		(1 << 6)
+
+#define TCS_SLEW_SHIFT		3
+#define TCS_SLEW_MASK		(0x3 < 3)
+
+#define FAN53200_NVOLTAGES	64	/* Numbers of voltages */
+
+enum fan53200_vendor {
+	FAN53200_VENDOR_FAIRCHILD = 0,
+};
+
+/* VSEL ID */
+enum {
+	FAN53200_VSEL_ID_0 = 0,
+	FAN53200_VSEL_ID_1,
+};
+
+enum {
+	FAN53200_CHIP_ID_00 = 0x8001,
+	FAN53200_CHIP_ID_01 = 0x8101,
+};
+
+struct fan53200_platform_data {
+	struct regulator_init_data *regulator;
+	unsigned int slew_rate;
+	/* Sleep VSEL ID */
+	unsigned int sleep_vsel_id;
+	struct gpio_desc *vsel_gpio;
+};
+
+struct fan53200_device_info {
+	enum fan53200_vendor vendor;
+	struct regmap *regmap;
+	struct device *dev;
+	struct regulator_desc desc;
+	struct regulator_dev *rdev;
+	struct regulator_init_data *regulator;
+	/* IC Type and Rev */
+	int chip_id;
+	int chip_rev;
+	/* Voltage setting register */
+	unsigned int vol_reg;
+	unsigned int sleep_reg;
+	unsigned int mode_reg;
+	unsigned int vol_mask;
+	unsigned int mode_mask;
+	unsigned int slew_reg;
+	unsigned int slew_mask;
+	unsigned int slew_shift;
+	/* Voltage range and step(linear) */
+	unsigned int vsel_min;
+	unsigned int vsel_step;
+	unsigned int n_voltages;
+	/* Voltage slew rate limiting */
+	unsigned int slew_rate;
+	/* Sleep voltage cache */
+	unsigned int sleep_vol_cache;
+	struct gpio_desc *vsel_gpio;
+	unsigned int sleep_vsel_id;
+};
+
+static unsigned int fan53200_map_mode(unsigned int mode)
+{
+	return mode == REGULATOR_MODE_FAST ?
+		REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
+}
+
+static int fan53200_set_suspend_voltage(struct regulator_dev *rdev, int uV)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+	int ret;
+
+	if (di->sleep_vol_cache == uV)
+		return 0;
+	ret = regulator_map_voltage_linear(rdev, uV, uV);
+	if (ret < 0)
+		return ret;
+	ret = regmap_update_bits(di->regmap, di->sleep_reg,
+				 di->vol_mask, ret);
+	if (ret < 0)
+		return ret;
+	/* Cache the sleep voltage setting.
+	 * Might not be the real voltage which is rounded */
+	di->sleep_vol_cache = uV;
+
+	return 0;
+}
+
+static int fan53200_set_suspend_enable(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+
+	return regmap_update_bits(di->regmap, di->sleep_reg,
+				  VSEL_BUCK_EN, VSEL_BUCK_EN);
+}
+
+static int fan53200_set_suspend_disable(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+
+	return regmap_update_bits(di->regmap, di->sleep_reg,
+				  VSEL_BUCK_EN, 0);
+}
+
+static int fan53200_set_enable(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+
+	if (di->vsel_gpio) {
+		gpiod_set_raw_value(di->vsel_gpio, !di->sleep_vsel_id);
+		return 0;
+	}
+
+	return regmap_update_bits(di->regmap, di->vol_reg,
+				  VSEL_BUCK_EN, VSEL_BUCK_EN);
+}
+
+static int fan53200_set_disable(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+
+	if (di->vsel_gpio) {
+		gpiod_set_raw_value(di->vsel_gpio, di->sleep_vsel_id);
+		return 0;
+	}
+
+	return regmap_update_bits(di->regmap, di->vol_reg,
+				  VSEL_BUCK_EN, 0);
+}
+
+static int fan53200_is_enabled(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+	unsigned int val;
+	int ret = 0;
+
+	if (di->vsel_gpio) {
+		if (di->sleep_vsel_id)
+			return !gpiod_get_raw_value(di->vsel_gpio);
+		else
+			return gpiod_get_raw_value(di->vsel_gpio);
+	}
+
+	ret = regmap_read(di->regmap, di->vol_reg, &val);
+	if (ret < 0)
+		return ret;
+	if (val & VSEL_BUCK_EN)
+		return 1;
+	else
+		return 0;
+}
+
+static int fan53200_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		regmap_update_bits(di->regmap, di->mode_reg,
+				   di->mode_mask, di->mode_mask);
+		break;
+	case REGULATOR_MODE_NORMAL:
+		regmap_update_bits(di->regmap, di->mode_reg, di->mode_mask, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static unsigned int fan53200_get_mode(struct regulator_dev *rdev)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+	unsigned int val;
+	int ret = 0;
+
+	ret = regmap_read(di->regmap, di->mode_reg, &val);
+	if (ret < 0)
+		return ret;
+	if (val & di->mode_mask)
+		return REGULATOR_MODE_FAST;
+	else
+		return REGULATOR_MODE_NORMAL;
+}
+
+static const int slew_rates[] = {
+	80000,
+	40000,
+	20000,
+	10000,
+	5000,
+	2500,
+	1250,
+	625,
+};
+
+static int fan53200_set_ramp(struct regulator_dev *rdev, int ramp)
+{
+	struct fan53200_device_info *di = rdev_get_drvdata(rdev);
+	int regval = -1, i;
+
+	for (i = 0; i < ARRAY_SIZE(slew_rates); i++) {
+		if (ramp <= slew_rates[i])
+			regval = i;
+		else
+			break;
+	}
+
+	if (regval < 0) {
+		dev_err(di->dev, "unsupported ramp value %d\n", ramp);
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(di->regmap, di->slew_reg,
+				  di->slew_mask, regval << di->slew_shift);
+}
+
+static struct regulator_ops fan53200_regulator_ops = {
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_time_sel = regulator_set_voltage_time_sel,
+	.map_voltage = regulator_map_voltage_linear,
+	.list_voltage = regulator_list_voltage_linear,
+	.set_suspend_voltage = fan53200_set_suspend_voltage,
+	.enable = fan53200_set_enable,
+	.disable = fan53200_set_disable,
+	.is_enabled = fan53200_is_enabled,
+	.set_mode = fan53200_set_mode,
+	.get_mode = fan53200_get_mode,
+	.set_ramp_delay = fan53200_set_ramp,
+	.set_suspend_enable = fan53200_set_suspend_enable,
+	.set_suspend_disable = fan53200_set_suspend_disable,
+};
+
+static int fan53200_voltages_setup_fairchild(struct fan53200_device_info *di)
+{
+
+	if (di->sleep_vsel_id) {
+		di->sleep_reg = FAN53200_VSEL0;
+		di->vol_reg = FAN53200_VSEL1;
+	} else {
+		di->sleep_reg = FAN53200_VSEL1;
+		di->vol_reg = FAN53200_VSEL0;
+	}
+
+	/* Init voltage range and step */
+	di->vsel_min = 600000;
+	di->vsel_step = 12500;
+	di->vol_mask = VSEL_NSEL_MASK;
+	di->mode_reg = di->vol_reg;
+	di->mode_mask = VSEL_MODE;
+	di->slew_reg = FAN53200_CONTROL;
+	di->slew_mask = CTL_SLEW_MASK;
+	di->slew_shift = CTL_SLEW_SHIFT;
+	di->n_voltages = FAN53200_NVOLTAGES;
+
+	return 0;
+}
+
+/* For 00,01,03,05 options:
+ * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
+ * For 04 option:
+ * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
+ * */
+static int fan53200_device_setup(struct fan53200_device_info *di,
+				struct fan53200_platform_data *pdata)
+{
+	int ret = 0;
+
+	ret = fan53200_voltages_setup_fairchild(di);
+
+	return ret;
+}
+
+static int fan53200_regulator_register(struct fan53200_device_info *di,
+			struct regulator_config *config)
+{
+	struct regulator_desc *rdesc = &di->desc;
+
+	rdesc->name = "fan53200-reg";
+	rdesc->supply_name = "vin";
+	rdesc->ops = &fan53200_regulator_ops;
+	rdesc->type = REGULATOR_VOLTAGE;
+	rdesc->n_voltages = di->n_voltages;
+	rdesc->enable_reg = di->vol_reg;
+	rdesc->enable_mask = VSEL_BUCK_EN;
+	rdesc->min_uV = di->vsel_min;
+	rdesc->uV_step = di->vsel_step;
+	rdesc->vsel_reg = di->vol_reg;
+	rdesc->vsel_mask = di->vol_mask;
+	rdesc->owner = THIS_MODULE;
+	rdesc->enable_time = 400;
+
+	di->rdev = devm_regulator_register(di->dev, &di->desc, config);
+	return PTR_ERR_OR_ZERO(di->rdev);
+}
+
+static const struct regmap_config fan53200_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static struct fan53200_platform_data *fan53200_parse_dt(struct device *dev,
+					      struct device_node *np,
+					      const struct regulator_desc *desc)
+{
+	struct fan53200_platform_data *pdata;
+	int ret, flag;
+	u32 tmp;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	pdata->regulator = of_get_regulator_init_data(dev, np, desc);
+	pdata->regulator->constraints.initial_state = PM_SUSPEND_MEM;
+
+	ret = of_property_read_u32(np, "fcs,suspend-voltage-selector",
+				   &tmp);
+	if (!ret)
+		pdata->sleep_vsel_id = tmp;
+
+	if (pdata->sleep_vsel_id)
+		flag = GPIOD_OUT_LOW;
+	else
+		flag = GPIOD_OUT_HIGH;
+
+	pdata->vsel_gpio =
+		devm_gpiod_get_index_optional(dev, "vsel", 0,
+					      flag);
+	if (IS_ERR(pdata->vsel_gpio)) {
+		ret = PTR_ERR(pdata->vsel_gpio);
+		dev_err(dev, "failed to get vesl gpio (%d)\n", ret);
+	}
+
+	return pdata;
+}
+
+static const struct of_device_id fan53200_dt_ids[] = {
+	{
+		.compatible = "fcs,fan53200",
+		.data = (void *)FAN53200_VENDOR_FAIRCHILD,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, fan53200_dt_ids);
+
+static int fan53200_regulator_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct device_node *np = client->dev.of_node;
+	struct fan53200_device_info *di;
+	struct fan53200_platform_data *pdata;
+	struct regulator_config config = { };
+	unsigned int val;
+	int ret;
+
+	di = devm_kzalloc(&client->dev, sizeof(struct fan53200_device_info),
+					GFP_KERNEL);
+	if (!di)
+		return -ENOMEM;
+
+	di->desc.of_map_mode = fan53200_map_mode;
+
+	pdata = dev_get_platdata(&client->dev);
+	if (!pdata)
+		pdata = fan53200_parse_dt(&client->dev, np, &di->desc);
+
+	if (!pdata || !pdata->regulator) {
+		dev_err(&client->dev, "Platform data not found!\n");
+		return -ENODEV;
+	}
+
+	di->vsel_gpio = pdata->vsel_gpio;
+	di->sleep_vsel_id = pdata->sleep_vsel_id;
+
+	di->regulator = pdata->regulator;
+	if (client->dev.of_node) {
+		const struct of_device_id *match;
+
+		match = of_match_device(of_match_ptr(fan53200_dt_ids),
+					&client->dev);
+		if (!match)
+			return -ENODEV;
+
+		di->vendor = (unsigned long) match->data;
+	} else {
+		/* if no ramp constraint set, get the pdata ramp_delay */
+		if (!di->regulator->constraints.ramp_delay) {
+			int slew_idx = (pdata->slew_rate & 0x7)
+						? pdata->slew_rate : 0;
+
+			di->regulator->constraints.ramp_delay
+						= slew_rates[slew_idx];
+		}
+
+		di->vendor = id->driver_data;
+	}
+
+	di->regmap = devm_regmap_init_i2c(client, &fan53200_regmap_config);
+	if (IS_ERR(di->regmap)) {
+		dev_err(&client->dev, "Failed to allocate regmap!\n");
+		return PTR_ERR(di->regmap);
+	}
+	di->dev = &client->dev;
+	i2c_set_clientdata(client, di);
+	/* Get chip ID */
+	ret = regmap_read(di->regmap, FAN53200_ID1, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to get chip ID!\n");
+		return ret;
+	}
+	di->chip_id = val & DIE_ID;
+	/* Get chip revision */
+	ret = regmap_read(di->regmap, FAN53200_ID2, &val);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to get chip Rev!\n");
+		return ret;
+	}
+	di->chip_rev = val & DIE_REV;
+	dev_info(&client->dev, "FAN53200 Option[%d] Rev[%d] Detected!\n",
+				di->chip_id, di->chip_rev);
+	/* Device init */
+	ret = fan53200_device_setup(di, pdata);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to setup device!\n");
+		return ret;
+	}
+	/* Register regulator */
+	config.dev = di->dev;
+	config.init_data = di->regulator;
+	config.regmap = di->regmap;
+	config.driver_data = di;
+	config.of_node = np;
+
+	ret = fan53200_regulator_register(di, &config);
+	if (ret < 0)
+		dev_err(&client->dev, "Failed to register regulator!\n");
+	return ret;
+
+}
+
+static const struct i2c_device_id fan53200_id[] = {
+	{
+		.name = "fan53200",
+		.driver_data = FAN53200_VENDOR_FAIRCHILD
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, fan53200_id);
+
+static struct i2c_driver fan53200_regulator_driver = {
+	.driver = {
+		.name = "fan53200-regulator",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = of_match_ptr(fan53200_dt_ids),
+	},
+	.probe = fan53200_regulator_probe,
+	.id_table = fan53200_id,
+};
+
+module_i2c_driver(fan53200_regulator_driver);
+
+MODULE_AUTHOR("Rock Shen <rock_shen@asus.com>");
+MODULE_DESCRIPTION("FAN53200 regulator driver");
+MODULE_LICENSE("GPL v2");
-- 
Armbian

