drm/rockchip: ebc: Add silergy sy7636a regulator driver

Change-Id: I76eea176a49d4a56e3f6a92c0aff5648ecbe5a4f
Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>

drivers/gpu/drm/rockchip/ebc-dev/Kconfig

@@ -9,3 +9,9 @@ config EPD_TPS65185_SENSOR
     bool "eink pmic Tps65185"
     depends on ROCKCHIP_EBC_DEV
     default y
+
+config EPD_SY7636A_PMIC
+	bool "EINK PMIC SY7636A Support"
+	depends on ROCKCHIP_EBC_DEV
+	help
+	  If you say yes here you get support for the Silergy SY7636A PMIC.

drivers/gpu/drm/rockchip/ebc-dev/pmic/Makefile

@@ -3,3 +3,4 @@
 obj-$(CONFIG_ROCKCHIP_EBC_DEV) += ebc_pmic.o
 obj-$(CONFIG_EPD_TPS65185_SENSOR) += tps65185.o
 obj-$(CONFIG_ROCKCHIP_EBC_DEV) += ebc_pmic_mfd.o
+obj-$(CONFIG_EPD_SY7636A_PMIC) += sy7636a-regulator.o

drivers/gpu/drm/rockchip/ebc-dev/pmic/ebc_pmic_mfd.c

@@ -62,7 +62,17 @@ static int pmic_mfd_i2c_probe(struct i2c_client *i2c)
 	return 0;
 }
 
+static const struct mfd_cell sy7636a_cells[] = {
+	{ .name = "sy7636a-regulator", },
+};
+
+static struct pmic_mfd_data silergy_sy7636a = {
+	.mfd_cell = sy7636a_cells,
+	.mfd_cell_size = ARRAY_SIZE(sy7636a_cells),
+};
+
 static const struct of_device_id pmic_mfd_i2c_of_match[] = {
+	{ .compatible = "silergy,sy7636a-pmic", .data = &silergy_sy7636a},
 	{}
 };
 MODULE_DEVICE_TABLE(of, pmic_mfd_i2c_of_match);

drivers/gpu/drm/rockchip/ebc-dev/pmic/sy7636a-regulator.c

@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Rockchip Electronics Co., Ltd.
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/regmap.h>
+#include "sy7636a.h"
+
+#define SY7636A_MAX_ENABLE_GPIO_NUM 4
+
+struct sy7636a_data {
+	struct regmap *regmap;
+	struct gpio_descs *enable_gpio;
+	/*
+	 * When registering a new regulator, regulator core will try to
+	 * call "set_suspend_disable" to check whether regulator device
+	 * working well.
+	 * Just skip this suspend to avoid reconfiguring pinctrl.
+	 */
+	bool initial_suspend;
+	int vcom_uV;
+};
+
+static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
+{
+	int ret;
+	unsigned int val, val_h;
+
+	ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
+	if (ret)
+		return ret;
+
+	val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
+
+	return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
+}
+
+static int sy7636a_set_vcom_voltage_op(struct regulator_dev *rdev, int min_uV, int max_uV,
+				       unsigned int *selector)
+{
+	struct sy7636a_data *data = rdev->reg_data;
+	int min_mV = DIV_ROUND_UP(min_uV, 1000);
+	int max_mV = max_uV / 1000;
+	u32 val;
+	int ret;
+
+	if (max_mV < min_mV)
+		return -EINVAL;
+
+	val = min_mV / 10;
+
+	ret = regmap_write(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, val & 0xFF);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, (val >> 1) & 0x80);
+	if (ret)
+		return ret;
+
+	data->vcom_uV = min_uV;
+
+	return 0;
+}
+
+static int sy7636a_get_status(struct regulator_dev *rdev)
+{
+	return 0;
+}
+
+static int sy7636a_set_suspend_disable(struct regulator_dev *rdev)
+{
+	DECLARE_BITMAP(values, SY7636A_MAX_ENABLE_GPIO_NUM);
+	struct sy7636a_data *data = rdev->reg_data;
+	int ret;
+
+	bitmap_zero(values, SY7636A_MAX_ENABLE_GPIO_NUM);
+
+	/* Skip initial suspend */
+	if (data->initial_suspend) {
+		data->initial_suspend = false;
+		return 0;
+	}
+
+	ret = regmap_write_bits(rdev->regmap, SY7636A_REG_OPERATION_MODE_CRL,
+				SY7636A_OPERATION_MODE_CRL_VCOMCTL, 0);
+	if (ret)
+		return ret;
+
+	if (data->enable_gpio) {
+		ret = gpiod_set_array_value_cansleep(data->enable_gpio->ndescs,
+						     data->enable_gpio->desc,
+						     data->enable_gpio->info, values);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int sy7636a_resume(struct regulator_dev *rdev)
+{
+	DECLARE_BITMAP(values, SY7636A_MAX_ENABLE_GPIO_NUM);
+	struct sy7636a_data *data = rdev->reg_data;
+	int ret, val;
+
+	bitmap_fill(values, SY7636A_MAX_ENABLE_GPIO_NUM);
+
+	if (data->enable_gpio) {
+		ret = gpiod_set_array_value_cansleep(data->enable_gpio->ndescs,
+						     data->enable_gpio->desc,
+						     data->enable_gpio->info, values);
+		if (ret)
+			return ret;
+	}
+
+	/* After enable, sy7636a needs 2.5ms to enter active mode from sleep mode. */
+	usleep_range(2500, 2600);
+
+	/* VCOM setting resume */
+	val = data->vcom_uV / VCOM_ADJUST_CTRL_SCAL;
+
+	ret = regmap_write(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, val & 0xFF);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, (val >> 1) & 0x80);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(rdev->regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(rdev->regmap, SY7636A_REG_OPERATION_MODE_CRL,
+				SY7636A_OPERATION_MODE_CRL_VCOMCTL, 1);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct regulator_ops sy7636a_vcom_volt_ops = {
+	.set_voltage = sy7636a_set_vcom_voltage_op,
+	.get_voltage = sy7636a_get_vcom_voltage_op,
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.get_status = sy7636a_get_status,
+	.set_suspend_disable = sy7636a_set_suspend_disable,
+	.resume = sy7636a_resume,
+};
+
+static const struct regulator_desc desc = {
+	.name = "vcom",
+	.id = 0,
+	.ops = &sy7636a_vcom_volt_ops,
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+	.enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
+	.enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
+	.regulators_node = of_match_ptr("regulators"),
+	.of_match = of_match_ptr("vcom"),
+};
+
+static int sy7636a_regulator_probe(struct platform_device *pdev)
+{
+	struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	struct regulator_config config = { };
+	struct regulator_dev *rdev;
+	struct sy7636a_data *data;
+	int ret, val, val_h;
+
+	if (!regmap)
+		return -EPROBE_DEFER;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct sy7636a_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = regmap;
+	data->initial_suspend = true;
+
+	data->enable_gpio = devm_gpiod_get_array_optional(pdev->dev.parent, "enable",
+							  GPIOD_OUT_HIGH);
+	if (IS_ERR(data->enable_gpio)) {
+		dev_err(pdev->dev.parent, "Failed to get sy7636a enable gpio %ld\n",
+			PTR_ERR(data->enable_gpio));
+		return PTR_ERR(data->enable_gpio);
+	}
+
+	/* sy7636a needs 2.5ms to enter active mode after enable */
+	usleep_range(2500, 2600);
+
+	ret = regmap_write(regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
+	if (ret)
+		goto fail;
+
+	ret = regmap_read(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
+	if (ret)
+		goto fail;
+
+	ret = regmap_read(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
+	if (ret)
+		goto fail;
+
+	val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
+	data->vcom_uV = (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
+
+	platform_set_drvdata(pdev, data);
+
+	config.dev = &pdev->dev;
+	config.dev->of_node = pdev->dev.parent->of_node;
+	config.regmap = regmap;
+	config.driver_data = data;
+
+	rdev = devm_regulator_register(&pdev->dev, &desc, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(pdev->dev.parent, "Failed to register %s regulator\n", pdev->name);
+		return PTR_ERR(rdev);
+	}
+
+	return 0;
+
+fail:
+	dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n", ret);
+	return ret;
+}
+
+static const struct platform_device_id sy7636a_regulator_id_table[] = {
+	{ "sy7636a-regulator", },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
+
+static struct platform_driver sy7636a_regulator_driver = {
+	.driver = {
+		.name = "sy7636a-regulator",
+	},
+	.probe = sy7636a_regulator_probe,
+	.id_table = sy7636a_regulator_id_table,
+};
+module_platform_driver(sy7636a_regulator_driver);
+
+MODULE_DESCRIPTION("SY7636A voltage regulator driver");
+MODULE_LICENSE("GPL");

drivers/gpu/drm/rockchip/ebc-dev/pmic/sy7636a.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Rockchip Electronics Co., Ltd.
+ */
+
+#ifndef SY7636A_H
+#define SY7636A_H
+
+#define SY7636A_REG_OPERATION_MODE_CRL		0x00
+/* It is set if a gpio is used to control the regulator */
+#define SY7636A_OPERATION_MODE_CRL_VCOMCTL	BIT(6)
+#define SY7636A_OPERATION_MODE_CRL_ONOFF	BIT(7)
+#define SY7636A_REG_VCOM_ADJUST_CTRL_L		0x01
+#define SY7636A_REG_VCOM_ADJUST_CTRL_H		0x02
+#define SY7636A_REG_VCOM_ADJUST_CTRL_MASK	0x01ff
+#define SY7636A_REG_VLDO_VOLTAGE_ADJULST_CTRL	0x03
+#define SY7636A_REG_POWER_ON_DELAY_TIME		0x06
+#define SY7636A_REG_FAULT_FLAG			0x07
+#define SY7636A_FAULT_FLAG_PG			BIT(0)
+#define SY7636A_REG_TERMISTOR_READOUT		0x08
+
+#define SY7636A_REG_MAX				0x08
+
+#define VCOM_ADJUST_CTRL_MASK	0x1ff
+/* Used to shift the high byte */
+#define VCOM_ADJUST_CTRL_SHIFT	8
+/* Used to scale from VCOM_ADJUST_CTRL to mv */
+#define VCOM_ADJUST_CTRL_SCAL	10000
+
+#define FAULT_FLAG_SHIFT	1
+
+#endif /* SY7636A_H */