Re: [PATCH v9] leds: add support for TI LP5860 LED driver chip

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

Hi Steffen,

On 4/24/26 3:28 PM, Steffen Trumtrar wrote:
> Add support for the Texas Instruments LP5860 LED driver chip
> via SPI interfaces.
> 
> The LP5860 is an LED matrix driver for up to 196 LEDs, which supports
> short and open detection of the individual channel select lines.
> 
> It can be connected to SPI or I2C bus. For now add support for SPI only.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> ---
[...]
> diff --git a/drivers/leds/rgb/leds-lp5860-core.c b/drivers/leds/rgb/leds-lp5860-core.c
> new file mode 100644
> index 0000000000000..648bf168f94bf
> --- /dev/null
> +++ b/drivers/leds/rgb/leds-lp5860-core.c
> @@ -0,0 +1,231 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2025 Pengutronix
> + *
> + * Author: Steffen Trumtrar <kernel@pengutronix.de>
> + */
> +
> +#include <linux/led-class-multicolor.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +
> +#include "leds-lp5860.h"
> +
> +static struct lp5860_led *mcled_cdev_to_led(struct led_classdev_mc *mc_cdev)
> +{
> +	return container_of(mc_cdev, struct lp5860_led, mc_cdev);
> +}
> +
> +static int lp5860_set_dot_onoff(struct lp5860_led *led, unsigned int dot, bool enable)
> +{
> +	unsigned int offset = dot / LP5860_MAX_DOT_ONOFF_GROUP_NUM;
> +	unsigned int mask = BIT(dot % LP5860_MAX_DOT_ONOFF_GROUP_NUM);
> +
> +	if (dot > LP5860_MAX_LED)
> +		return -EINVAL;
> +
> +	return regmap_update_bits(led->chip->regmap,
> +				  LP5860_REG_DOT_ONOFF_START + offset, mask,
> +				  enable ? LP5860_DOT_ALL_ON : LP5860_DOT_ALL_OFF);
> +}
> +
> +static int lp5860_set_mc_brightness(struct led_classdev *cdev,
> +				    enum led_brightness brightness)
> +{
> +	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> +	struct lp5860_led *led = mcled_cdev_to_led(mc_cdev);

You need mutex locking while accessing hw to avoid leaving the
device in an inconsistent state in case of two parallel requests from
different processes.

> +	led_mc_calc_color_components(mc_cdev, brightness);
> +
> +	for (int i = 0; i < led->mc_cdev.num_colors; i++) {
> +		unsigned int channel = mc_cdev->subled_info[i].channel;
> +		unsigned int led_brightness = mc_cdev->subled_info[i].brightness;
> +		int ret;
> +
> +		ret = lp5860_set_dot_onoff(led, channel, !!led_brightness);
> +		if (ret)
> +			return ret;
> +
> +		ret = regmap_write(led->chip->regmap,
> +				   LP5860_REG_PWM_BRI_START + channel, led_brightness);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lp5860_chip_enable(struct lp5860 *lp, bool enable)
> +{
> +	return regmap_write(lp->regmap, LP5860_REG_CHIP_EN, enable);


-- 
Best regards,
Jacek Anaszewski