Re: [PATCH v3 16/23] leds: max77705: Add LEDs support

Krzysztof Kozlowski
2024-06-20T20:15:13Z

On 18/06/2024 15:59, Dzmitry Sankouski wrote:
> This adds basic support for LEDs for the max77705 PMIC.
>
> Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
> ---
> MAINTAINERS | 1 +
> drivers/leds/Kconfig | 6 ++
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-max77705.c | 166 +++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 174 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f66f08825db9..f3c245d432d9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13691,6 +13691,7 @@ F: drivers/*/max14577*.c
> F: drivers/*/max77686*.c
> F: drivers/*/max77693*.c
> F: drivers/*/max77705*.c
> +F: drivers/leds/leds-max77705.c
> F: drivers/clk/clk-max77686.c
> F: drivers/extcon/extcon-max14577.c
> F: drivers/extcon/extcon-max77693.c
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 05e6af88b88c..14d483011308 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -728,6 +728,12 @@ config LEDS_MAX77650
> help
> LEDs driver for MAX77650 family of PMICs from Maxim Integrated.
>
> +config LEDS_MAX77705
> + tristate "LED support for Maxim MAX77705 RGB"
> + depends on MFD_MAX77705 && LEDS_CLASS && I2C
> + help
> + LED driver for MAX77705 MFD chip from Maxim Integrated.
> +
> config LEDS_MAX8997
> tristate "LED support for MAX8997 PMIC"
> depends on LEDS_CLASS && MFD_MAX8997
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index effdfc6f1e95..be064e3d678e 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -58,6 +58,7 @@ obj-$(CONFIG_LEDS_LP8860) += leds-lp8860.o
> obj-$(CONFIG_LEDS_LT3593) += leds-lt3593.o
> obj-$(CONFIG_LEDS_MAX5970) += leds-max5970.o
> obj-$(CONFIG_LEDS_MAX77650) += leds-max77650.o
> +obj-$(CONFIG_LEDS_MAX77705) += leds-max77705.o
> obj-$(CONFIG_LEDS_MAX8997) += leds-max8997.o
> obj-$(CONFIG_LEDS_MC13783) += leds-mc13783.o
> obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
> diff --git a/drivers/leds/leds-max77705.c b/drivers/leds/leds-max77705.c
> new file mode 100644
> index 000000000000..f91c0e41056c
> --- /dev/null
> +++ b/drivers/leds/leds-max77705.c
> @@ -0,0 +1,166 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Based on leds-max77650 driver:
> + * Copyright (C) 2018 BayLibre SAS
> + * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> + *
> + * LED driver for MAXIM 77705 MFD.
> + * Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail.org>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/mfd/max77705.h>
> +#include <linux/mfd/max77705-private.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define MAX77705_LED_NUM_LEDS 4
> +#define MAX77705_LED_EN_MASK GENMASK(1, 0)
> +#define MAX77705_LED_MAX_BRIGHTNESS 0xff
> +
> +#define LEDBLNK_ON(time) ((time < 100) ? 0 : \
> + (time < 500) ? time/100-1 : \
> + (time < 3250) ? (time-500)/250+4 : 15)
> +
> +#define LEDBLNK_OFF(time) ((time < 1) ? 0x00 : \
> + (time < 500) ? 0x01 : \
> + (time < 5000) ? time/500 : \
> + (time < 8000) ? (time-5000)/1000+10 : \
> + (time < 12000) ? (time-8000)/2000+13 : 15)

Make both static functions, if really needed, but these appear only in
one place, so maybe just code it directly.

> +
> +struct max77705_led {
> + struct led_classdev cdev;
> + struct regmap *regmap;
> + unsigned int en_shift;
> + unsigned int reg_brightness;
> + unsigned int regB;

noCamelCase.

> +};
> +
> +static struct max77705_led *max77705_to_led(struct led_classdev *cdev)
> +{
> + return container_of(cdev, struct max77705_led, cdev);
> +}
> +

> + led = &leds[reg];
> + led->regmap = map;
> + led->reg_brightness = MAX77705_RGBLED_REG_LED0BRT + reg;
> + led->en_shift = 2 * reg;
> + led->cdev.brightness_set_blocking = max77705_led_brightness_set;
> + led->cdev.blink_set = max77705_rgb_blink;
> + led->cdev.max_brightness = MAX77705_LED_MAX_BRIGHTNESS;
> +
> + init_data.fwnode = child;
> + init_data.devicename = "max77705";
> + /* for backwards compatibility if `label` is not present */
> + init_data.default_label = ":";

There is no backwards compatibility - it's fresh driver.

> +
> + rv = devm_led_classdev_register_ext(dev, &led->cdev,
> + &init_data);
> + if (rv)
> + goto err_node_put;
> +
> + rv = max77705_led_brightness_set(&led->cdev, LED_OFF);
> + if (rv)
> + goto err_node_put;
> + }
> +
> + return 0;
> +err_node_put:
> + fwnode_handle_put(child);
> + return rv;
> +}
> +
> +static const struct of_device_id max77705_led_of_match[] = {
> + { .compatible = "maxim,max77705-led" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, max77705_led_of_match);
> +
> +static struct platform_driver max77705_led_driver = {
> + .driver = {
> + .name = "max77705-led",
> + .of_match_table = max77705_led_of_match,
> + },
> + .probe = max77705_led_probe,
> +};
> +module_platform_driver(max77705_led_driver);
> +
> +MODULE_DESCRIPTION("MAXIM 77705 LED driver");
> +MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
> +MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:max77705-led");

You should not need MODULE_ALIAS() in normal cases. If you need it,
usually it means your device ID table is wrong (e.g. misses either
entries or MODULE_DEVICE_TABLE()). MODULE_ALIAS() is not a substitute
for incomplete ID table.

Best regards,
Krzysztof