| ChiYuan Huang | 3367ac3 | 2021-05-17 22:35:58 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright (c) 2021 Richtek Technology Corp. |
| 4 | * |
| 5 | * Author: ChiYuan Huang <cy_huang@richtek.com> |
| 6 | */ |
| 7 | |
| 8 | #include <linux/gpio/consumer.h> |
| 9 | #include <linux/i2c.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/mfd/core.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/regmap.h> |
| 14 | |
| 15 | #define RT4831_REG_REVISION 0x01 |
| 16 | #define RT4831_REG_ENABLE 0x08 |
| 17 | #define RT4831_REG_I2CPROT 0x15 |
| 18 | |
| 19 | #define RICHTEK_VENDOR_ID 0x03 |
| 20 | #define RT4831_VID_MASK GENMASK(1, 0) |
| 21 | #define RT4831_RESET_MASK BIT(7) |
| 22 | #define RT4831_I2CSAFETMR_MASK BIT(0) |
| 23 | |
| 24 | static const struct mfd_cell rt4831_subdevs[] = { |
| 25 | MFD_CELL_OF("rt4831-backlight", NULL, NULL, 0, 0, "richtek,rt4831-backlight"), |
| 26 | MFD_CELL_NAME("rt4831-regulator") |
| 27 | }; |
| 28 | |
| 29 | static bool rt4831_is_accessible_reg(struct device *dev, unsigned int reg) |
| 30 | { |
| 31 | if (reg >= RT4831_REG_REVISION && reg <= RT4831_REG_I2CPROT) |
| 32 | return true; |
| 33 | return false; |
| 34 | } |
| 35 | |
| 36 | static const struct regmap_config rt4831_regmap_config = { |
| 37 | .reg_bits = 8, |
| 38 | .val_bits = 8, |
| 39 | .max_register = RT4831_REG_I2CPROT, |
| 40 | |
| 41 | .readable_reg = rt4831_is_accessible_reg, |
| 42 | .writeable_reg = rt4831_is_accessible_reg, |
| 43 | }; |
| 44 | |
| 45 | static int rt4831_probe(struct i2c_client *client) |
| 46 | { |
| 47 | struct gpio_desc *enable_gpio; |
| 48 | struct regmap *regmap; |
| 49 | unsigned int chip_id; |
| 50 | int ret; |
| 51 | |
| 52 | enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH); |
| 53 | if (IS_ERR(enable_gpio)) { |
| 54 | dev_err(&client->dev, "Failed to get 'enable' GPIO\n"); |
| 55 | return PTR_ERR(enable_gpio); |
| 56 | } |
| 57 | |
| 58 | regmap = devm_regmap_init_i2c(client, &rt4831_regmap_config); |
| 59 | if (IS_ERR(regmap)) { |
| 60 | dev_err(&client->dev, "Failed to initialize regmap\n"); |
| 61 | return PTR_ERR(regmap); |
| 62 | } |
| 63 | |
| 64 | ret = regmap_read(regmap, RT4831_REG_REVISION, &chip_id); |
| 65 | if (ret) { |
| 66 | dev_err(&client->dev, "Failed to get H/W revision\n"); |
| 67 | return ret; |
| 68 | } |
| 69 | |
| 70 | if ((chip_id & RT4831_VID_MASK) != RICHTEK_VENDOR_ID) { |
| 71 | dev_err(&client->dev, "Chip vendor ID 0x%02x not matched\n", chip_id); |
| 72 | return -ENODEV; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Used to prevent the abnormal shutdown. |
| 77 | * If SCL/SDA both keep low for one second to reset HW. |
| 78 | */ |
| 79 | ret = regmap_update_bits(regmap, RT4831_REG_I2CPROT, RT4831_I2CSAFETMR_MASK, |
| 80 | RT4831_I2CSAFETMR_MASK); |
| 81 | if (ret) { |
| 82 | dev_err(&client->dev, "Failed to enable I2C safety timer\n"); |
| 83 | return ret; |
| 84 | } |
| 85 | |
| 86 | return devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO, rt4831_subdevs, |
| 87 | ARRAY_SIZE(rt4831_subdevs), NULL, 0, NULL); |
| 88 | } |
| 89 | |
| 90 | static int rt4831_remove(struct i2c_client *client) |
| 91 | { |
| 92 | struct regmap *regmap = dev_get_regmap(&client->dev, NULL); |
| 93 | |
| 94 | /* Disable WLED and DSV outputs */ |
| 95 | return regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK); |
| 96 | } |
| 97 | |
| 98 | static const struct of_device_id __maybe_unused rt4831_of_match[] = { |
| 99 | { .compatible = "richtek,rt4831", }, |
| 100 | {} |
| 101 | }; |
| 102 | MODULE_DEVICE_TABLE(of, rt4831_of_match); |
| 103 | |
| 104 | static struct i2c_driver rt4831_driver = { |
| 105 | .driver = { |
| 106 | .name = "rt4831", |
| 107 | .of_match_table = rt4831_of_match, |
| 108 | }, |
| 109 | .probe_new = rt4831_probe, |
| 110 | .remove = rt4831_remove, |
| 111 | }; |
| 112 | module_i2c_driver(rt4831_driver); |
| 113 | |
| 114 | MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>"); |
| 115 | MODULE_LICENSE("GPL v2"); |