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