--- /dev/null
+// 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");
projects / users / willy / xarray.git / commitdiff