diff options
Diffstat (limited to 'drivers/mfd/rt4831.c')
| -rw-r--r-- | drivers/mfd/rt4831.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/mfd/rt4831.c b/drivers/mfd/rt4831.c new file mode 100644 index 0000000000..f8d6dc55b5 --- /dev/null +++ b/drivers/mfd/rt4831.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2021 Richtek Technology Corp. + * + * Author: ChiYuan Huang <cy_huang@richtek.com> + */ + +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/mfd/core.h> +#include <linux/module.h> +#include <linux/regmap.h> + +#define RT4831_REG_REVISION 0x01 +#define RT4831_REG_ENABLE 0x08 +#define RT4831_REG_I2CPROT 0x15 + +#define RICHTEK_VENDOR_ID 0x03 +#define RT4831_VID_MASK GENMASK(1, 0) +#define RT4831_RESET_MASK BIT(7) +#define RT4831_I2CSAFETMR_MASK BIT(0) + +static const struct mfd_cell rt4831_subdevs[] = { + MFD_CELL_OF("rt4831-backlight", NULL, NULL, 0, 0, "richtek,rt4831-backlight"), + MFD_CELL_NAME("rt4831-regulator") +}; + +static bool rt4831_is_accessible_reg(struct device *dev, unsigned int reg) +{ + if (reg >= RT4831_REG_REVISION && reg <= RT4831_REG_I2CPROT) + return true; + return false; +} + +static const struct regmap_config rt4831_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = RT4831_REG_I2CPROT, + + .readable_reg = rt4831_is_accessible_reg, + .writeable_reg = rt4831_is_accessible_reg, +}; + +static int rt4831_probe(struct i2c_client *client) +{ + struct gpio_desc *enable_gpio; + struct regmap *regmap; + unsigned int chip_id; + int ret; + + enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH); + if (IS_ERR(enable_gpio)) { + dev_err(&client->dev, "Failed to get 'enable' GPIO\n"); + return PTR_ERR(enable_gpio); + } + + regmap = devm_regmap_init_i2c(client, &rt4831_regmap_config); + if (IS_ERR(regmap)) { + dev_err(&client->dev, "Failed to initialize regmap\n"); + return PTR_ERR(regmap); + } + + ret = regmap_read(regmap, RT4831_REG_REVISION, &chip_id); + if (ret) { + dev_err(&client->dev, "Failed to get H/W revision\n"); + return ret; + } + + if ((chip_id & RT4831_VID_MASK) != RICHTEK_VENDOR_ID) { + dev_err(&client->dev, "Chip vendor ID 0x%02x not matched\n", chip_id); + return -ENODEV; + } + + /* + * Used to prevent the abnormal shutdown. + * If SCL/SDA both keep low for one second to reset HW. + */ + ret = regmap_update_bits(regmap, RT4831_REG_I2CPROT, RT4831_I2CSAFETMR_MASK, + RT4831_I2CSAFETMR_MASK); + if (ret) { + dev_err(&client->dev, "Failed to enable I2C safety timer\n"); + return ret; + } + + return devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO, rt4831_subdevs, + ARRAY_SIZE(rt4831_subdevs), NULL, 0, NULL); +} + +static void rt4831_remove(struct i2c_client *client) +{ + struct regmap *regmap = dev_get_regmap(&client->dev, NULL); + int ret; + + /* Disable WLED and DSV outputs */ + ret = regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK); + if (ret) + dev_warn(&client->dev, "Failed to disable outputs (%pe)\n", ERR_PTR(ret)); +} + +static const struct of_device_id __maybe_unused rt4831_of_match[] = { + { .compatible = "richtek,rt4831", }, + {} +}; +MODULE_DEVICE_TABLE(of, rt4831_of_match); + +static struct i2c_driver rt4831_driver = { + .driver = { + .name = "rt4831", + .of_match_table = rt4831_of_match, + }, + .probe = rt4831_probe, + .remove = rt4831_remove, +}; +module_i2c_driver(rt4831_driver); + +MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>"); +MODULE_LICENSE("GPL v2"); |