diff options
Diffstat (limited to 'drivers/regulator/max20086-regulator.c')
| -rw-r--r-- | drivers/regulator/max20086-regulator.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/regulator/max20086-regulator.c b/drivers/regulator/max20086-regulator.c new file mode 100644 index 000000000000..fbc56b043071 --- /dev/null +++ b/drivers/regulator/max20086-regulator.c @@ -0,0 +1,332 @@ +// 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/err.h> +#include <linux/gpio.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 0x40 +#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[MAX20086_MAX_REGULATORS] = { }; + struct device_node *node; + unsigned int i; + int ret; + + node = of_get_child_by_name(chip->dev->of_node, "regulators"); + if (!node) { + dev_err(chip->dev, "regulators node not found\n"); + return PTR_ERR(node); + } + + 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); + of_node_put(node); + 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 = device_get_match_data(chip->dev); + + 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(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 i2c_device_id max20086_i2c_id[] = { + { "max20086" }, + { "max20087" }, + { "max20088" }, + { "max20089" }, + { /* Sentinel */ }, +}; + +MODULE_DEVICE_TABLE(i2c, max20086_i2c_id); + +static const struct of_device_id max20086_dt_ids[] = { + { + .compatible = "maxim,max20086", + .data = &(const struct max20086_chip_info) { + .id = MAX20086_DEVICE_ID_MAX20086, + .num_outputs = 4, + } + }, { + .compatible = "maxim,max20087", + .data = &(const struct max20086_chip_info) { + .id = MAX20086_DEVICE_ID_MAX20087, + .num_outputs = 4, + } + }, { + .compatible = "maxim,max20088", + .data = &(const struct max20086_chip_info) { + .id = MAX20086_DEVICE_ID_MAX20088, + .num_outputs = 2, + } + }, { + .compatible = "maxim,max20089", + .data = &(const struct max20086_chip_info) { + .id = MAX20086_DEVICE_ID_MAX20089, + .num_outputs = 2, + } + }, + { /* Sentinel */ }, +}; + +MODULE_DEVICE_TABLE(of, max20086_dt_ids); + +static struct i2c_driver max20086_regulator_driver = { + .driver = { + .name = "max20086", + .of_match_table = of_match_ptr(max20086_dt_ids), + }, + .probe_new = 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"); |