drivers/regulator/max8952.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * max8952.c - Voltage and current regulation for the Maxim 8952
  *
  * Copyright (C) 2010 Samsung Electronics
  * MyungJoo Ham <myungjoo.ham@samsung.com>
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/max8952.h>
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/slab.h>

 /* Registers */
 enum {
 	MAX8952_REG_MODE0,
 	MAX8952_REG_MODE1,
 	MAX8952_REG_MODE2,
 	MAX8952_REG_MODE3,
 	MAX8952_REG_CONTROL,
 	MAX8952_REG_SYNC,
 	MAX8952_REG_RAMP,
 	MAX8952_REG_CHIP_ID1,
 	MAX8952_REG_CHIP_ID2,
 };

 struct max8952_data {
 	struct i2c_client	*client;
 	struct max8952_platform_data *pdata;
 	struct gpio_desc *vid0_gpiod;
 	struct gpio_desc *vid1_gpiod;
 	bool vid0;
 	bool vid1;
 };

 static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
 {
 	int ret = i2c_smbus_read_byte_data(max8952->client, reg);

 	if (ret > 0)
 		ret &= 0xff;

 	return ret;
 }

 static int max8952_write_reg(struct max8952_data *max8952,
 		u8 reg, u8 value)
 {
 	return i2c_smbus_write_byte_data(max8952->client, reg, value);
 }

 static int max8952_list_voltage(struct regulator_dev *rdev,
 		unsigned int selector)
 {
 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

 	if (rdev_get_id(rdev) != 0)
 		return -EINVAL;

 	return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
 }

 static int max8952_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
 	u8 vid = 0;

 	if (max8952->vid0)
 		vid += 1;
 	if (max8952->vid1)
 		vid += 2;

 	return vid;
 }

 static int max8952_set_voltage_sel(struct regulator_dev *rdev,
 				   unsigned selector)
 {
 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

 	if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
 		/* DVS not supported */
 		return -EPERM;
 	}

 	max8952->vid0 = selector & 0x1;
 	max8952->vid1 = (selector >> 1) & 0x1;
 	gpiod_set_value(max8952->vid0_gpiod, max8952->vid0);
 	gpiod_set_value(max8952->vid1_gpiod, max8952->vid1);

 	return 0;
 }

 static const struct regulator_ops max8952_ops = {
 	.list_voltage		= max8952_list_voltage,
 	.get_voltage_sel	= max8952_get_voltage_sel,
 	.set_voltage_sel	= max8952_set_voltage_sel,
 };

 static const struct regulator_desc regulator = {
 	.name		= "MAX8952_VOUT",
 	.id		= 0,
 	.n_voltages	= MAX8952_NUM_DVS_MODE,
 	.ops		= &max8952_ops,
 	.type		= REGULATOR_VOLTAGE,
 	.owner		= THIS_MODULE,
 };

 #ifdef CONFIG_OF
 static const struct of_device_id max8952_dt_match[] = {
 	{ .compatible = "maxim,max8952" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, max8952_dt_match);

 static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
 {
 	struct max8952_platform_data *pd;
 	struct device_node *np = dev->of_node;
 	int ret;
 	int i;

 	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
 	if (!pd)
 		return NULL;

 	if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
 		dev_warn(dev, "Default mode not specified, assuming 0\n");

 	ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
 					pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
 	if (ret) {
 		dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
 		return NULL;
 	}

 	for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
 		if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
 			dev_err(dev, "DVS voltage %d out of range\n", i);
 			return NULL;
 		}
 		pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
 	}

 	if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
 		dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");

 	if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
 		dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");

 	pd->reg_data = of_get_regulator_init_data(dev, np, &regulator);
 	if (!pd->reg_data) {
 		dev_err(dev, "Failed to parse regulator init data\n");
 		return NULL;
 	}

 	return pd;
 }
 #else
 static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
 {
 	return NULL;
 }
 #endif

 static int max8952_pmic_probe(struct i2c_client *client,
 		const struct i2c_device_id *i2c_id)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct regulator_config config = { };
 	struct max8952_data *max8952;
 	struct regulator_dev *rdev;
 	struct gpio_desc *gpiod;
 	enum gpiod_flags gflags;

 	int ret = 0;

 	if (client->dev.of_node)
 		pdata = max8952_parse_dt(&client->dev);

 	if (!pdata) {
 		dev_err(&client->dev, "Require the platform data\n");
 		return -EINVAL;
 	}

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 		return -EIO;

 	max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
 			       GFP_KERNEL);
 	if (!max8952)
 		return -ENOMEM;

 	max8952->client = client;
 	max8952->pdata = pdata;

 	config.dev = &client->dev;
 	config.init_data = pdata->reg_data;
 	config.driver_data = max8952;
 	config.of_node = client->dev.of_node;

 	if (pdata->reg_data->constraints.boot_on)
 		gflags = GPIOD_OUT_HIGH;
 	else
 		gflags = GPIOD_OUT_LOW;
 	gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
 	/*
 	 * Do not use devm* here: the regulator core takes over the
 	 * lifecycle management of the GPIO descriptor.
 	 */
 	gpiod = gpiod_get_optional(&client->dev,
 				   "max8952,en",
 				   gflags);
 	if (IS_ERR(gpiod))
 		return PTR_ERR(gpiod);
 	if (gpiod)
 		config.ena_gpiod = gpiod;

 	rdev = devm_regulator_register(&client->dev, &regulator, &config);
 	if (IS_ERR(rdev)) {
 		ret = PTR_ERR(rdev);
 		dev_err(&client->dev, "regulator init failed (%d)\n", ret);
 		return ret;
 	}

 	max8952->vid0 = pdata->default_mode & 0x1;
 	max8952->vid1 = (pdata->default_mode >> 1) & 0x1;

 	/* Fetch vid0 and vid1 GPIOs if available */
 	gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 	max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev,
 							    "max8952,vid",
 							    0, gflags);
 	if (IS_ERR(max8952->vid0_gpiod))
 		return PTR_ERR(max8952->vid0_gpiod);
 	gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 	max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev,
 							    "max8952,vid",
 							    1, gflags);
 	if (IS_ERR(max8952->vid1_gpiod))
 		return PTR_ERR(max8952->vid1_gpiod);

 	/* If either VID GPIO is missing just disable this */
 	if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {
 		dev_warn(&client->dev, "VID0/1 gpio invalid: "
 			 "DVS not available.\n");
 		max8952->vid0 = 0;
 		max8952->vid1 = 0;
 		/* Make sure if we have any descriptors they get set to low */
 		if (max8952->vid0_gpiod)
 			gpiod_set_value(max8952->vid0_gpiod, 0);
 		if (max8952->vid1_gpiod)
 			gpiod_set_value(max8952->vid1_gpiod, 0);

 		/* Disable Pulldown of EN only */
 		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);

 		dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
 				" do not have proper controls.\n");
 	} else {
 		/*
 		 * Disable Pulldown on EN, VID0, VID1 to reduce
 		 * leakage current of MAX8952 assuming that MAX8952
 		 * is turned on (EN==1). Note that without having VID0/1
 		 * properly connected, turning pulldown off can be
 		 * problematic. Thus, turn this off only when they are
 		 * controllable by GPIO.
 		 */
 		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
 	}

 	max8952_write_reg(max8952, MAX8952_REG_MODE0,
 			(max8952_read_reg(max8952,
 					  MAX8952_REG_MODE0) & 0xC0) |
 			(pdata->dvs_mode[0] & 0x3F));
 	max8952_write_reg(max8952, MAX8952_REG_MODE1,
 			(max8952_read_reg(max8952,
 					  MAX8952_REG_MODE1) & 0xC0) |
 			(pdata->dvs_mode[1] & 0x3F));
 	max8952_write_reg(max8952, MAX8952_REG_MODE2,
 			(max8952_read_reg(max8952,
 					  MAX8952_REG_MODE2) & 0xC0) |
 			(pdata->dvs_mode[2] & 0x3F));
 	max8952_write_reg(max8952, MAX8952_REG_MODE3,
 			(max8952_read_reg(max8952,
 					  MAX8952_REG_MODE3) & 0xC0) |
 			(pdata->dvs_mode[3] & 0x3F));

 	max8952_write_reg(max8952, MAX8952_REG_SYNC,
 			(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
 			((pdata->sync_freq & 0x3) << 6));
 	max8952_write_reg(max8952, MAX8952_REG_RAMP,
 			(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
 			((pdata->ramp_speed & 0x7) << 5));

 	i2c_set_clientdata(client, max8952);

 	return 0;
 }

 static const struct i2c_device_id max8952_ids[] = {
 	{ "max8952", 0 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, max8952_ids);

 static struct i2c_driver max8952_pmic_driver = {
 	.probe		= max8952_pmic_probe,
 	.driver		= {
 		.name	= "max8952",
 		.of_match_table = of_match_ptr(max8952_dt_match),
 	},
 	.id_table	= max8952_ids,
 };

 static int __init max8952_pmic_init(void)
 {
 	return i2c_add_driver(&max8952_pmic_driver);
 }
 subsys_initcall(max8952_pmic_init);

 static void __exit max8952_pmic_exit(void)
 {
 	i2c_del_driver(&max8952_pmic_driver);
 }
 module_exit(max8952_pmic_exit);

 MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* max8952.c - Voltage and current regulation for the Maxim 8952
	*
	* Copyright (C) 2010 Samsung Electronics
	* MyungJoo Ham <myungjoo.ham@samsung.com>
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/i2c.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/max8952.h>
	#include <linux/gpio/consumer.h>
	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/regulator/of_regulator.h>
	#include <linux/slab.h>

	/* Registers */
	enum {
	MAX8952_REG_MODE0,
	MAX8952_REG_MODE1,
	MAX8952_REG_MODE2,
	MAX8952_REG_MODE3,
	MAX8952_REG_CONTROL,
	MAX8952_REG_SYNC,
	MAX8952_REG_RAMP,
	MAX8952_REG_CHIP_ID1,
	MAX8952_REG_CHIP_ID2,
	};

	struct max8952_data {
	struct i2c_client *client;
	struct max8952_platform_data *pdata;
	struct gpio_desc *vid0_gpiod;
	struct gpio_desc *vid1_gpiod;
	bool vid0;
	bool vid1;
	};

	static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
	{
	int ret = i2c_smbus_read_byte_data(max8952->client, reg);

	if (ret > 0)
	ret &= 0xff;

	return ret;
	}

	static int max8952_write_reg(struct max8952_data *max8952,
	u8 reg, u8 value)
	{
	return i2c_smbus_write_byte_data(max8952->client, reg, value);
	}

	static int max8952_list_voltage(struct regulator_dev *rdev,
	unsigned int selector)
	{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

	if (rdev_get_id(rdev) != 0)
	return -EINVAL;

	return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
	}

	static int max8952_get_voltage_sel(struct regulator_dev *rdev)
	{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
	u8 vid = 0;

	if (max8952->vid0)
	vid += 1;
	if (max8952->vid1)
	vid += 2;

	return vid;
	}

	static int max8952_set_voltage_sel(struct regulator_dev *rdev,
	unsigned selector)
	{
	struct max8952_data *max8952 = rdev_get_drvdata(rdev);

	if (!max8952->vid0_gpiod \|\| !max8952->vid1_gpiod) {
	/* DVS not supported */
	return -EPERM;
	}

	max8952->vid0 = selector & 0x1;
	max8952->vid1 = (selector >> 1) & 0x1;
	gpiod_set_value(max8952->vid0_gpiod, max8952->vid0);
	gpiod_set_value(max8952->vid1_gpiod, max8952->vid1);

	return 0;
	}

	static const struct regulator_ops max8952_ops = {
	.list_voltage = max8952_list_voltage,
	.get_voltage_sel = max8952_get_voltage_sel,
	.set_voltage_sel = max8952_set_voltage_sel,
	};

	static const struct regulator_desc regulator = {
	.name = "MAX8952_VOUT",
	.id = 0,
	.n_voltages = MAX8952_NUM_DVS_MODE,
	.ops = &max8952_ops,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	};

	#ifdef CONFIG_OF
	static const struct of_device_id max8952_dt_match[] = {
	{ .compatible = "maxim,max8952" },
	{},
	};
	MODULE_DEVICE_TABLE(of, max8952_dt_match);

	static struct max8952_platform_data max8952_parse_dt(struct device dev)
	{
	struct max8952_platform_data *pd;
	struct device_node *np = dev->of_node;
	int ret;
	int i;

	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
	if (!pd)
	return NULL;

	if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
	dev_warn(dev, "Default mode not specified, assuming 0\n");

	ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
	pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
	if (ret) {
	dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
	return NULL;
	}

	for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
	if (pd->dvs_mode[i] < 770000 \|\| pd->dvs_mode[i] > 1400000) {
	dev_err(dev, "DVS voltage %d out of range\n", i);
	return NULL;
	}
	pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
	}

	if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
	dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");

	if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
	dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");

	pd->reg_data = of_get_regulator_init_data(dev, np, &regulator);
	if (!pd->reg_data) {
	dev_err(dev, "Failed to parse regulator init data\n");
	return NULL;
	}

	return pd;
	}
	#else
	static struct max8952_platform_data max8952_parse_dt(struct device dev)
	{
	return NULL;
	}
	#endif

	static int max8952_pmic_probe(struct i2c_client *client,
	const struct i2c_device_id *i2c_id)
	{
	struct i2c_adapter *adapter = client->adapter;
	struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
	struct regulator_config config = { };
	struct max8952_data *max8952;
	struct regulator_dev *rdev;
	struct gpio_desc *gpiod;
	enum gpiod_flags gflags;

	int ret = 0;

	if (client->dev.of_node)
	pdata = max8952_parse_dt(&client->dev);

	if (!pdata) {
	dev_err(&client->dev, "Require the platform data\n");
	return -EINVAL;
	}

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
	return -EIO;

	max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
	GFP_KERNEL);
	if (!max8952)
	return -ENOMEM;

	max8952->client = client;
	max8952->pdata = pdata;

	config.dev = &client->dev;
	config.init_data = pdata->reg_data;
	config.driver_data = max8952;
	config.of_node = client->dev.of_node;

	if (pdata->reg_data->constraints.boot_on)
	gflags = GPIOD_OUT_HIGH;
	else
	gflags = GPIOD_OUT_LOW;
	gflags \|= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
	/*
	* Do not use devm* here: the regulator core takes over the
	* lifecycle management of the GPIO descriptor.
	*/
	gpiod = gpiod_get_optional(&client->dev,
	"max8952,en",
	gflags);
	if (IS_ERR(gpiod))
	return PTR_ERR(gpiod);
	if (gpiod)
	config.ena_gpiod = gpiod;

	rdev = devm_regulator_register(&client->dev, &regulator, &config);
	if (IS_ERR(rdev)) {
	ret = PTR_ERR(rdev);
	dev_err(&client->dev, "regulator init failed (%d)\n", ret);
	return ret;
	}

	max8952->vid0 = pdata->default_mode & 0x1;
	max8952->vid1 = (pdata->default_mode >> 1) & 0x1;

	/* Fetch vid0 and vid1 GPIOs if available */
	gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
	max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev,
	"max8952,vid",
	0, gflags);
	if (IS_ERR(max8952->vid0_gpiod))
	return PTR_ERR(max8952->vid0_gpiod);
	gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
	max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev,
	"max8952,vid",
	1, gflags);
	if (IS_ERR(max8952->vid1_gpiod))
	return PTR_ERR(max8952->vid1_gpiod);

	/* If either VID GPIO is missing just disable this */
	if (!max8952->vid0_gpiod \|\| !max8952->vid1_gpiod) {
	dev_warn(&client->dev, "VID0/1 gpio invalid: "
	"DVS not available.\n");
	max8952->vid0 = 0;
	max8952->vid1 = 0;
	/* Make sure if we have any descriptors they get set to low */
	if (max8952->vid0_gpiod)
	gpiod_set_value(max8952->vid0_gpiod, 0);
	if (max8952->vid1_gpiod)
	gpiod_set_value(max8952->vid1_gpiod, 0);

	/* Disable Pulldown of EN only */
	max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);

	dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
	" do not have proper controls.\n");
	} else {
	/*
	* Disable Pulldown on EN, VID0, VID1 to reduce
	* leakage current of MAX8952 assuming that MAX8952
	* is turned on (EN==1). Note that without having VID0/1
	* properly connected, turning pulldown off can be
	* problematic. Thus, turn this off only when they are
	* controllable by GPIO.
	*/
	max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
	}

	max8952_write_reg(max8952, MAX8952_REG_MODE0,
	(max8952_read_reg(max8952,
	MAX8952_REG_MODE0) & 0xC0) \|
	(pdata->dvs_mode[0] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE1,
	(max8952_read_reg(max8952,
	MAX8952_REG_MODE1) & 0xC0) \|
	(pdata->dvs_mode[1] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE2,
	(max8952_read_reg(max8952,
	MAX8952_REG_MODE2) & 0xC0) \|
	(pdata->dvs_mode[2] & 0x3F));
	max8952_write_reg(max8952, MAX8952_REG_MODE3,
	(max8952_read_reg(max8952,
	MAX8952_REG_MODE3) & 0xC0) \|
	(pdata->dvs_mode[3] & 0x3F));

	max8952_write_reg(max8952, MAX8952_REG_SYNC,
	(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) \|
	((pdata->sync_freq & 0x3) << 6));
	max8952_write_reg(max8952, MAX8952_REG_RAMP,
	(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) \|
	((pdata->ramp_speed & 0x7) << 5));

	i2c_set_clientdata(client, max8952);

	return 0;
	}

	static const struct i2c_device_id max8952_ids[] = {
	{ "max8952", 0 },
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, max8952_ids);

	static struct i2c_driver max8952_pmic_driver = {
	.probe = max8952_pmic_probe,
	.driver = {
	.name = "max8952",
	.of_match_table = of_match_ptr(max8952_dt_match),
	},
	.id_table = max8952_ids,
	};

	static int __init max8952_pmic_init(void)
	{
	return i2c_add_driver(&max8952_pmic_driver);
	}
	subsys_initcall(max8952_pmic_init);

	static void __exit max8952_pmic_exit(void)
	{
	i2c_del_driver(&max8952_pmic_driver);
	}
	module_exit(max8952_pmic_exit);

	MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
	MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
	MODULE_LICENSE("GPL");