[PATCH 2/8] regulator: add support for SY8824C regulator

[Jisheng Zhang]

SY8824C is an I2C attached single output regulator made by Silergy Corp,
which is used on several Synaptics berlin platforms to control the
power supply of the ARM cores.

Add a driver for it.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
---
 drivers/regulator/Kconfig   |   7 ++
 drivers/regulator/Makefile  |   1 +
 drivers/regulator/sy8824x.c | 192 ++++++++++++++++++++++++++++++++++++
 3 files changed, 200 insertions(+)
 create mode 100644 drivers/regulator/sy8824x.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index b57093d7c01f..e8093a909e85 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -906,6 +906,13 @@ config REGULATOR_SY8106A
 	help
 	  This driver supports SY8106A single output regulator.
 
+config REGULATOR_SY8824X
+	tristate "Silergy SY8824C regulator"
+	depends on I2C && (OF || COMPILE_TEST)
+	select REGMAP_I2C
+	help
+	  This driver supports SY8824C single output regulator.
+
 config REGULATOR_TPS51632
 	tristate "TI TPS51632 Power Regulator"
 	depends on I2C
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index eef73b5a35a4..922bf975070f 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -111,6 +111,7 @@ obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o
 obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o
 obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o
 obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o
+obj-$(CONFIG_REGULATOR_SY8824X) += sy8824x.o
 obj-$(CONFIG_REGULATOR_TI_ABB) += ti-abb-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6105X) += tps6105x-regulator.o
 obj-$(CONFIG_REGULATOR_TPS62360) += tps62360-regulator.o
diff --git a/drivers/regulator/sy8824x.c b/drivers/regulator/sy8824x.c
new file mode 100644
index 000000000000..2d8a61ca6643
--- /dev/null
+++ b/drivers/regulator/sy8824x.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SY8824C regulator driver
+ *
+ * Copyright (C) 2019 Synaptics Incorporated
+ *
+ * Author: Jisheng Zhang <jszhang@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define BUCK_EN		(1 << 7)
+#define MODE		(1 << 6)
+
+struct sy8824_config {
+	/* registers */
+	unsigned int vol_reg;
+	unsigned int mode_reg;
+	unsigned int enable_reg;
+	/* Voltage range and step(linear) */
+	unsigned int vsel_min;
+	unsigned int vsel_step;
+	unsigned int vsel_count;
+};
+
+struct sy8824_device_info {
+	struct device *dev;
+	struct regulator_desc desc;
+	struct regulator_init_data *regulator;
+	const struct sy8824_config *cfg;
+};
+
+static int sy8824_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	struct sy8824_device_info *di = rdev_get_drvdata(rdev);
+	const struct sy8824_config *cfg = di->cfg;
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		regmap_update_bits(rdev->regmap, cfg->mode_reg, MODE, MODE);
+		break;
+	case REGULATOR_MODE_NORMAL:
+		regmap_update_bits(rdev->regmap, cfg->mode_reg, MODE, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static unsigned int sy8824_get_mode(struct regulator_dev *rdev)
+{
+	struct sy8824_device_info *di = rdev_get_drvdata(rdev);
+	const struct sy8824_config *cfg = di->cfg;
+	u32 val;
+	int ret = 0;
+
+	ret = regmap_read(rdev->regmap, cfg->mode_reg, &val);
+	if (ret < 0)
+		return ret;
+	if (val & MODE)
+		return REGULATOR_MODE_FAST;
+	else
+		return REGULATOR_MODE_NORMAL;
+}
+
+static const struct regulator_ops sy8824_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,
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.set_mode = sy8824_set_mode,
+	.get_mode = sy8824_get_mode,
+};
+
+static int sy8824_regulator_register(struct sy8824_device_info *di,
+			struct regulator_config *config)
+{
+	struct regulator_desc *rdesc = &di->desc;
+	const struct sy8824_config *cfg = di->cfg;
+	struct regulator_dev *rdev;
+
+	rdesc->name = "sy8824-reg";
+	rdesc->supply_name = "vin";
+	rdesc->ops = &sy8824_regulator_ops;
+	rdesc->type = REGULATOR_VOLTAGE;
+	rdesc->n_voltages = cfg->vsel_count;
+	rdesc->enable_reg = cfg->enable_reg;
+	rdesc->enable_mask = BUCK_EN;
+	rdesc->min_uV = cfg->vsel_min;
+	rdesc->uV_step = cfg->vsel_step;
+	rdesc->vsel_reg = cfg->vol_reg;
+	rdesc->vsel_mask = cfg->vsel_count - 1;
+	rdesc->owner = THIS_MODULE;
+
+	rdev = devm_regulator_register(di->dev, &di->desc, config);
+	return PTR_ERR_OR_ZERO(rdev);
+}
+
+static const struct regmap_config sy8824_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int sy8824_i2c_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = dev->of_node;
+	struct sy8824_device_info *di;
+	struct regulator_config config = { };
+	struct regmap *regmap;
+	int ret;
+
+	di = devm_kzalloc(dev, sizeof(struct sy8824_device_info), GFP_KERNEL);
+	if (!di)
+		return -ENOMEM;
+
+	di->regulator = of_get_regulator_init_data(dev, np, &di->desc);
+	if (!di->regulator) {
+		dev_err(dev, "Platform data not found!\n");
+		return -EINVAL;
+	}
+
+	di->dev = dev;
+	di->cfg = of_device_get_match_data(dev);
+
+	regmap = devm_regmap_init_i2c(client, &sy8824_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "Failed to allocate regmap!\n");
+		return PTR_ERR(regmap);
+	}
+	i2c_set_clientdata(client, di);
+
+	config.dev = di->dev;
+	config.init_data = di->regulator;
+	config.regmap = regmap;
+	config.driver_data = di;
+	config.of_node = np;
+
+	ret = sy8824_regulator_register(di, &config);
+	if (ret < 0)
+		dev_err(dev, "Failed to register regulator!\n");
+	return ret;
+}
+
+static const struct sy8824_config sy8824c_cfg = {
+	.vol_reg = 0x00,
+	.mode_reg = 0x00,
+	.enable_reg = 0x00,
+	.vsel_min = 762500,
+	.vsel_step = 12500,
+	.vsel_count = 64,
+};
+
+static const struct of_device_id sy8824_dt_ids[] = {
+	{
+		.compatible = "silergy,sy8824c",
+		.data = &sy8824c_cfg
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sy8824_dt_ids);
+
+static const struct i2c_device_id sy8824_id[] = {
+	{ "sy8824", },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sy8824_id);
+
+static struct i2c_driver sy8824_regulator_driver = {
+	.driver = {
+		.name = "sy8824-regulator",
+		.of_match_table = of_match_ptr(sy8824_dt_ids),
+	},
+	.probe = sy8824_i2c_probe,
+	.id_table = sy8824_id,
+};
+module_i2c_driver(sy8824_regulator_driver);
+
+MODULE_AUTHOR("Jisheng Zhang <jszhang@xxxxxxxxxx>");
+MODULE_DESCRIPTION("SY8824C regulator driver");
+MODULE_LICENSE("GPL v2");
-- 
2.23.0.rc1