| // SPDX-License-Identifier: GPL-2.0-or-later | 
 | // | 
 | // max20086-regulator.c - MAX20086-MAX20089 camera power protector driver | 
 | // | 
 | // Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@idesonboard.com> | 
 | // Copyright (C) 2018 Avnet, Inc. | 
 |  | 
 | #include <linux/cleanup.h> | 
 | #include <linux/err.h> | 
 | #include <linux/gpio/consumer.h> | 
 | #include <linux/i2c.h> | 
 | #include <linux/module.h> | 
 | #include <linux/regmap.h> | 
 | #include <linux/regulator/driver.h> | 
 | #include <linux/regulator/machine.h> | 
 | #include <linux/regulator/of_regulator.h> | 
 | #include <linux/slab.h> | 
 |  | 
 | /* Register Offset */ | 
 | #define MAX20086_REG_MASK		0x00 | 
 | #define MAX20086_REG_CONFIG		0x01 | 
 | #define	MAX20086_REG_ID			0x02 | 
 | #define	MAX20086_REG_STAT1		0x03 | 
 | #define	MAX20086_REG_STAT2_L		0x04 | 
 | #define	MAX20086_REG_STAT2_H		0x05 | 
 | #define	MAX20086_REG_ADC1		0x06 | 
 | #define	MAX20086_REG_ADC2		0x07 | 
 | #define	MAX20086_REG_ADC3		0x08 | 
 | #define	MAX20086_REG_ADC4		0x09 | 
 |  | 
 | /* DEVICE IDs */ | 
 | #define MAX20086_DEVICE_ID_MAX20086	0x30 | 
 | #define MAX20086_DEVICE_ID_MAX20087	0x20 | 
 | #define MAX20086_DEVICE_ID_MAX20088	0x10 | 
 | #define MAX20086_DEVICE_ID_MAX20089	0x00 | 
 | #define DEVICE_ID_MASK			0xf0 | 
 |  | 
 | /* Register bits */ | 
 | #define MAX20086_EN_MASK		0x0f | 
 | #define MAX20086_EN_OUT1		0x01 | 
 | #define MAX20086_EN_OUT2		0x02 | 
 | #define MAX20086_EN_OUT3		0x04 | 
 | #define MAX20086_EN_OUT4		0x08 | 
 | #define MAX20086_INT_DISABLE_ALL	0x3f | 
 |  | 
 | #define MAX20086_MAX_REGULATORS		4 | 
 |  | 
 | struct max20086_chip_info { | 
 | 	u8 id; | 
 | 	unsigned int num_outputs; | 
 | }; | 
 |  | 
 | struct max20086_regulator { | 
 | 	struct device_node *of_node; | 
 | 	struct regulator_init_data *init_data; | 
 | 	const struct regulator_desc *desc; | 
 | 	struct regulator_dev *rdev; | 
 | }; | 
 |  | 
 | struct max20086 { | 
 | 	struct device *dev; | 
 | 	struct regmap *regmap; | 
 | 	struct gpio_desc *ena_gpiod; | 
 |  | 
 | 	const struct max20086_chip_info *info; | 
 |  | 
 | 	struct max20086_regulator regulators[MAX20086_MAX_REGULATORS]; | 
 | }; | 
 |  | 
 | static const struct regulator_ops max20086_buck_ops = { | 
 | 	.enable = regulator_enable_regmap, | 
 | 	.disable = regulator_disable_regmap, | 
 | 	.is_enabled = regulator_is_enabled_regmap, | 
 | }; | 
 |  | 
 | #define MAX20086_REGULATOR_DESC(n)		\ | 
 | {						\ | 
 | 	.name = "OUT"#n,			\ | 
 | 	.supply_name = "in",			\ | 
 | 	.id = (n) - 1,				\ | 
 | 	.ops = &max20086_buck_ops,		\ | 
 | 	.type = REGULATOR_VOLTAGE,		\ | 
 | 	.owner = THIS_MODULE,			\ | 
 | 	.enable_reg = MAX20086_REG_CONFIG,	\ | 
 | 	.enable_mask = 1 << ((n) - 1),		\ | 
 | 	.enable_val = 1 << ((n) - 1),		\ | 
 | 	.disable_val = 0,			\ | 
 | } | 
 |  | 
 | static const char * const max20086_output_names[] = { | 
 | 	"OUT1", | 
 | 	"OUT2", | 
 | 	"OUT3", | 
 | 	"OUT4", | 
 | }; | 
 |  | 
 | static const struct regulator_desc max20086_regulators[] = { | 
 | 	MAX20086_REGULATOR_DESC(1), | 
 | 	MAX20086_REGULATOR_DESC(2), | 
 | 	MAX20086_REGULATOR_DESC(3), | 
 | 	MAX20086_REGULATOR_DESC(4), | 
 | }; | 
 |  | 
 | static int max20086_regulators_register(struct max20086 *chip) | 
 | { | 
 | 	unsigned int i; | 
 |  | 
 | 	for (i = 0; i < chip->info->num_outputs; i++) { | 
 | 		struct max20086_regulator *reg = &chip->regulators[i]; | 
 | 		struct regulator_config config = { }; | 
 | 		struct regulator_dev *rdev; | 
 |  | 
 | 		config.dev = chip->dev; | 
 | 		config.init_data = reg->init_data; | 
 | 		config.driver_data = chip; | 
 | 		config.of_node = reg->of_node; | 
 | 		config.regmap = chip->regmap; | 
 | 		config.ena_gpiod = chip->ena_gpiod; | 
 |  | 
 | 		rdev = devm_regulator_register(chip->dev, reg->desc, &config); | 
 | 		if (IS_ERR(rdev)) { | 
 | 			dev_err(chip->dev, | 
 | 				"Failed to register regulator output %s\n", | 
 | 				reg->desc->name); | 
 | 			return PTR_ERR(rdev); | 
 | 		} | 
 |  | 
 | 		reg->rdev = rdev; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on) | 
 | { | 
 | 	struct of_regulator_match *matches; | 
 | 	unsigned int i; | 
 | 	int ret; | 
 |  | 
 | 	struct device_node *node __free(device_node) = | 
 | 		of_get_child_by_name(chip->dev->of_node, "regulators"); | 
 | 	if (!node) { | 
 | 		dev_err(chip->dev, "regulators node not found\n"); | 
 | 		return -ENODEV; | 
 | 	} | 
 |  | 
 | 	matches = devm_kcalloc(chip->dev, chip->info->num_outputs, | 
 | 			       sizeof(*matches), GFP_KERNEL); | 
 | 	if (!matches) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	for (i = 0; i < chip->info->num_outputs; ++i) | 
 | 		matches[i].name = max20086_output_names[i]; | 
 |  | 
 | 	ret = of_regulator_match(chip->dev, node, matches, | 
 | 				 chip->info->num_outputs); | 
 | 	if (ret < 0) { | 
 | 		dev_err(chip->dev, "Failed to match regulators\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	*boot_on = false; | 
 |  | 
 | 	for (i = 0; i < chip->info->num_outputs; i++) { | 
 | 		struct max20086_regulator *reg = &chip->regulators[i]; | 
 |  | 
 | 		reg->init_data = matches[i].init_data; | 
 | 		reg->of_node = matches[i].of_node; | 
 | 		reg->desc = &max20086_regulators[i]; | 
 |  | 
 | 		if (reg->init_data) { | 
 | 			if (reg->init_data->constraints.always_on || | 
 | 			    reg->init_data->constraints.boot_on) | 
 | 				*boot_on = true; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int max20086_detect(struct max20086 *chip) | 
 | { | 
 | 	unsigned int data; | 
 | 	int ret; | 
 |  | 
 | 	ret = regmap_read(chip->regmap, MAX20086_REG_ID, &data); | 
 | 	if (ret < 0) { | 
 | 		dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	if ((data & DEVICE_ID_MASK) != chip->info->id) { | 
 | 		dev_err(chip->dev, "Invalid device ID 0x%02x\n", data); | 
 | 		return -ENXIO; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg) | 
 | { | 
 | 	switch (reg) { | 
 | 	case MAX20086_REG_MASK: | 
 | 	case MAX20086_REG_CONFIG: | 
 | 		return true; | 
 | 	default: | 
 | 		return false; | 
 | 	} | 
 | } | 
 |  | 
 | static const struct regmap_config max20086_regmap_config = { | 
 | 	.reg_bits = 8, | 
 | 	.val_bits = 8, | 
 | 	.writeable_reg = max20086_gen_is_writeable_reg, | 
 | 	.max_register = 0x9, | 
 | 	.cache_type = REGCACHE_NONE, | 
 | }; | 
 |  | 
 | static int max20086_i2c_probe(struct i2c_client *i2c) | 
 | { | 
 | 	struct max20086 *chip; | 
 | 	enum gpiod_flags flags; | 
 | 	bool boot_on; | 
 | 	int ret; | 
 |  | 
 | 	chip = devm_kzalloc(&i2c->dev, sizeof(*chip), GFP_KERNEL); | 
 | 	if (!chip) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	chip->dev = &i2c->dev; | 
 | 	chip->info = i2c_get_match_data(i2c); | 
 |  | 
 | 	i2c_set_clientdata(i2c, chip); | 
 |  | 
 | 	chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config); | 
 | 	if (IS_ERR(chip->regmap)) { | 
 | 		ret = PTR_ERR(chip->regmap); | 
 | 		dev_err(chip->dev, "Failed to allocate register map: %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	ret = max20086_parse_regulators_dt(chip, &boot_on); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	ret = max20086_detect(chip); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	/* Until IRQ support is added, just disable all interrupts. */ | 
 | 	ret = regmap_update_bits(chip->regmap, MAX20086_REG_MASK, | 
 | 				 MAX20086_INT_DISABLE_ALL, | 
 | 				 MAX20086_INT_DISABLE_ALL); | 
 | 	if (ret < 0) { | 
 | 		dev_err(chip->dev, "Failed to disable interrupts: %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Get the enable GPIO. If any of the outputs is marked as being | 
 | 	 * enabled at boot, request the GPIO with an initial high state to | 
 | 	 * avoid disabling outputs that may have been turned on by the boot | 
 | 	 * loader. Otherwise, request it with a low state to enter lower-power | 
 | 	 * shutdown. | 
 | 	 */ | 
 | 	flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; | 
 | 	chip->ena_gpiod = devm_gpiod_get_optional(chip->dev, "enable", flags); | 
 | 	if (IS_ERR(chip->ena_gpiod)) { | 
 | 		ret = PTR_ERR(chip->ena_gpiod); | 
 | 		dev_err(chip->dev, "Failed to get enable GPIO: %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	ret = max20086_regulators_register(chip); | 
 | 	if (ret < 0) { | 
 | 		dev_err(chip->dev, "Failed to register regulators: %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static const struct max20086_chip_info max20086_chip_info = { | 
 | 	.id = MAX20086_DEVICE_ID_MAX20086, | 
 | 	.num_outputs = 4, | 
 | }; | 
 |  | 
 | static const struct max20086_chip_info max20087_chip_info = { | 
 | 	.id = MAX20086_DEVICE_ID_MAX20087, | 
 | 	.num_outputs = 4, | 
 | }; | 
 |  | 
 | static const struct max20086_chip_info max20088_chip_info = { | 
 | 	.id = MAX20086_DEVICE_ID_MAX20088, | 
 | 	.num_outputs = 2, | 
 | }; | 
 |  | 
 | static const struct max20086_chip_info max20089_chip_info = { | 
 | 	.id = MAX20086_DEVICE_ID_MAX20089, | 
 | 	.num_outputs = 2, | 
 | }; | 
 |  | 
 | static const struct i2c_device_id max20086_i2c_id[] = { | 
 | 	{ "max20086", (kernel_ulong_t)&max20086_chip_info }, | 
 | 	{ "max20087", (kernel_ulong_t)&max20087_chip_info }, | 
 | 	{ "max20088", (kernel_ulong_t)&max20088_chip_info }, | 
 | 	{ "max20089", (kernel_ulong_t)&max20089_chip_info }, | 
 | 	{ /* Sentinel */ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(i2c, max20086_i2c_id); | 
 |  | 
 | static const struct of_device_id max20086_dt_ids[] __maybe_unused = { | 
 | 	{ .compatible = "maxim,max20086", .data = &max20086_chip_info }, | 
 | 	{ .compatible = "maxim,max20087", .data = &max20087_chip_info }, | 
 | 	{ .compatible = "maxim,max20088", .data = &max20088_chip_info }, | 
 | 	{ .compatible = "maxim,max20089", .data = &max20089_chip_info }, | 
 | 	{ /* Sentinel */ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(of, max20086_dt_ids); | 
 |  | 
 | static struct i2c_driver max20086_regulator_driver = { | 
 | 	.driver = { | 
 | 		.name = "max20086", | 
 | 		.probe_type = PROBE_PREFER_ASYNCHRONOUS, | 
 | 		.of_match_table = of_match_ptr(max20086_dt_ids), | 
 | 	}, | 
 | 	.probe = max20086_i2c_probe, | 
 | 	.id_table = max20086_i2c_id, | 
 | }; | 
 |  | 
 | module_i2c_driver(max20086_regulator_driver); | 
 |  | 
 | MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>"); | 
 | MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver"); | 
 | MODULE_LICENSE("GPL"); |