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

[Steffen Trumtrar <s.trumtrar@pengutronix.de>]

On 2026-04-26 at 14:41 +02, Jacek Anaszewski <jacek.anaszewski@gmail.com> wrote:

Hi,

> 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.
>

The hw is only accessed via regmap. It handles locking AFAIK or do I misunderstand you?


Best regards,
Steffen

-- 
Pengutronix e.K.                | Dipl.-Inform. Steffen Trumtrar |
Steuerwalder Str. 21            | https://www.pengutronix.de/    |
31137 Hildesheim, Germany       | Phone: +49-5121-206917-0       |
Amtsgericht Hildesheim, HRA 2686| Fax:   +49-5121-206917-5555    |