// SPDX-License-Identifier: GPL-2.0-or-later
//
// max20086-regulator.c - MAX20086-MAX20089 camera power protector driver
//
// Copyright (C) 2022 Laurent Pinchart <[email protected]>
// Copyright (C) 2018 Avnet, Inc.
#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 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 -ENODEV;
}
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 = 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(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 <[email protected]>");
MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");
MODULE_LICENSE("GPL");
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