Re: [PATCH v6 1/4] mfd: rt4831: Adds support for Richtek RT4831

[ChiYuan Huang <u0084500@gmail.com>]

Hi, Linux mfd reviewers:
   It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

cy_huang <u0084500@gmail.com> 於 2021年3月28日 週日 下午11:24寫道：
>
> 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 b74efa4..3f43834 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1065,6 +1065,16 @@ 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 834f546..5986914 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -235,6 +235,7 @@ 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");
> --
> 2.7.4
>