From: ChiYuan Huang cy_huang@richtek.com
This adds support Richtek RT4831 core. It includes four channel WLED driver and Display Bias Voltage outputs.
Signed-off-by: ChiYuan Huang cy_huang@richtek.com --- The RT4831 regulator patches are already on main stream, and can be referred to 9351ab8b0cb6 regulator: rt4831: Adds support for Richtek RT4831 DSV regulator 934b05e81862 regulator: rt4831: Adds DT binding document for Richtek RT4831 DSV regulator
since v6 - Respin the date from 2020 to 2021. - Rmove the shutdown routine. - Change the macro OF_MFD_CELL to MFD_CELL_OF.
since v5 - Rename file name from rt4831-core.c to rt4831.c - Change RICHTEK_VID to RICHTEK_VENDOR_ID. - Change gpio_desc nameing from 'enable' to 'enable_gpio' in probe. - Change variable 'val' to the meaningful name 'chip_id'. - Refine the error log when vendor id is not matched. - Remove of_match_ptr.
since v2 - Refine Kconfig descriptions. - Add copyright. - Refine error logs in probe. - Refine comment lines in remove and shutdown. --- drivers/mfd/Kconfig | 10 +++++ drivers/mfd/Makefile | 1 + drivers/mfd/rt4831.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+) create mode 100644 drivers/mfd/rt4831.c
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 5c7f2b1..49e57c9 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1076,6 +1076,16 @@ config MFD_RDC321X southbridge which provides access to GPIOs and Watchdog using the southbridge PCI device configuration space.
+config MFD_RT4831 + tristate "Richtek RT4831 four channel WLED and Display Bias Voltage" + depends on I2C + select MFD_CORE + select REGMAP_I2C + help + This enables support for the Richtek RT4831 that includes 4 channel + WLED driving and Display Bias Voltage. It's commonly used to provide + power to the LCD display and LCD backlight. + config MFD_RT5033 tristate "Richtek RT5033 Power Management IC" depends on I2C diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 4f6d2b8..eb42bd4 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -234,6 +234,7 @@ obj-$(CONFIG_MFD_MENF21BMC) += menf21bmc.o obj-$(CONFIG_MFD_HI6421_PMIC) += hi6421-pmic-core.o obj-$(CONFIG_MFD_HI655X_PMIC) += hi655x-pmic.o obj-$(CONFIG_MFD_DLN2) += dln2.o +obj-$(CONFIG_MFD_RT4831) += rt4831.o obj-$(CONFIG_MFD_RT5033) += rt5033.o obj-$(CONFIG_MFD_SKY81452) += sky81452.o
diff --git a/drivers/mfd/rt4831.c b/drivers/mfd/rt4831.c new file mode 100644 index 00000000..b169781 --- /dev/null +++ b/drivers/mfd/rt4831.c @@ -0,0 +1,115 @@ +// 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 int rt4831_remove(struct i2c_client *client) +{ + struct regmap *regmap = dev_get_regmap(&client->dev, NULL); + + /* Disable WLED and DSV outputs */ + return regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK); +} + +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_new = rt4831_probe, + .remove = rt4831_remove, +}; +module_i2c_driver(rt4831_driver); + +MODULE_AUTHOR("ChiYuan Huang cy_huang@richtek.com"); +MODULE_LICENSE("GPL v2");