linux-kernel - Re: [PATCH v5 3/4] leds: led-class: Add devicetree support to led

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <g7xkdervsknmcwjg4qgloj643b4itjlfeyiipvsrborszgrhlg@zrp65nvfueqk>
Date: Tue, 16 Sep 2025 10:43:50 -0500
From: Bjorn Andersson <andersson@...nel.org>
To: Hans de Goede <hansg@...nel.org>
Cc: Lee Jones <lee@...nel.org>, Aleksandrs Vinarskis <alex@...arskis.com>, 
	Pavel Machek <pavel@...nel.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Bryan O'Donoghue <bryan.odonoghue@...aro.org>, Jingoo Han <jingoohan1@...il.com>, 
	Mauro Carvalho Chehab <mchehab@...nel.org>, Jean-Jacques Hiblot <jjhiblot@...phandler.com>, 
	Jacopo Mondi <jacopo@...ndi.org>, Sakari Ailus <sakari.ailus@...ux.intel.com>, 
	Konrad Dybcio <konradybcio@...nel.org>, Daniel Thompson <danielt@...nel.org>, linux-leds@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
	linux-media@...r.kernel.org, linux-arm-msm@...r.kernel.org, threeway@...il.com, 
	Andy Shevchenko <andy.shevchenko@...il.com>, Linus Walleij <linus.walleij@...aro.org>
Subject: Re: [PATCH v5 3/4] leds: led-class: Add devicetree support to
 led_get()

On Thu, Sep 11, 2025 at 11:01:00AM +0200, Hans de Goede wrote:
> Hi Lee,
> 
> On 11-Sep-25 10:15 AM, Lee Jones wrote:
> > On Wed, 10 Sep 2025, Aleksandrs Vinarskis wrote:
> > 
> >> From: Hans de Goede <hansg@...nel.org>
> >>
> >> Add 'name' argument to of_led_get() such that it can lookup LEDs in
> >> devicetree by either name or index.
> >>
> >> And use this modified function to add devicetree support to the generic
> >> (non devicetree specific) [devm_]led_get() function.
> >>
> >> This uses the standard devicetree pattern of adding a -names string array
> >> to map names to the indexes for an array of resources.
> >>
> >> Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>
> >> Reviewed-by: Lee Jones <lee@...nel.org>
> > 
> > Remind me why this can't go in through LED again?
> 
> I don't think anyone has discussed how to merge this yet.
> 
> I believe that the LED tree is the correct tree to merge this
> entire series through, once the DT bits have been reviewed.
> 

Unless there are some strong reasons (that I'm failing to spot), we
should merge the DeviceTree binding and implementation through the LED
tree. Then I merge the DTS change through the Qualcomm DT tree once the
bindings are available in linux-next.

Regards,
Bjorn

> Regards,
> 
> Hans
> 
> 
> 
> 
> >> Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
> >> Signed-off-by: Hans de Goede <hansg@...nel.org>
> >> Signed-off-by: Aleksandrs Vinarskis <alex@...arskis.com>
> >> ---
> >>  drivers/leds/led-class.c | 17 +++++++++++++++--
> >>  1 file changed, 15 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> >> index 15633fbf3c166aa4f521774d245f6399a642bced..f3faf37f9a08ac762ed87b91cb3cab5faa8eacb0 100644
> >> --- a/drivers/leds/led-class.c
> >> +++ b/drivers/leds/led-class.c
> >> @@ -252,15 +252,23 @@ static const struct class leds_class = {
> >>   * of_led_get() - request a LED device via the LED framework
> >>   * @np: device node to get the LED device from
> >>   * @index: the index of the LED
> >> + * @name: the name of the LED used to map it to its function, if present
> >>   *
> >>   * Returns the LED device parsed from the phandle specified in the "leds"
> >>   * property of a device tree node or a negative error-code on failure.
> >>   */
> >> -static struct led_classdev *of_led_get(struct device_node *np, int index)
> >> +static struct led_classdev *of_led_get(struct device_node *np, int index,
> >> +				       const char *name)
> >>  {
> >>  	struct device *led_dev;
> >>  	struct device_node *led_node;
> >>  
> >> +	/*
> >> +	 * For named LEDs, first look up the name in the "led-names" property.
> >> +	 * If it cannot be found, then of_parse_phandle() will propagate the error.
> >> +	 */
> >> +	if (name)
> >> +		index = of_property_match_string(np, "led-names", name);
> >>  	led_node = of_parse_phandle(np, "leds", index);
> >>  	if (!led_node)
> >>  		return ERR_PTR(-ENOENT);
> >> @@ -324,7 +332,7 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
> >>  	if (!dev)
> >>  		return ERR_PTR(-EINVAL);
> >>  
> >> -	led = of_led_get(dev->of_node, index);
> >> +	led = of_led_get(dev->of_node, index, NULL);
> >>  	if (IS_ERR(led))
> >>  		return led;
> >>  
> >> @@ -342,9 +350,14 @@ EXPORT_SYMBOL_GPL(devm_of_led_get);
> >>  struct led_classdev *led_get(struct device *dev, char *con_id)
> >>  {
> >>  	struct led_lookup_data *lookup;
> >> +	struct led_classdev *led_cdev;
> >>  	const char *provider = NULL;
> >>  	struct device *led_dev;
> >>  
> >> +	led_cdev = of_led_get(dev->of_node, -1, con_id);
> >> +	if (!IS_ERR(led_cdev) || PTR_ERR(led_cdev) != -ENOENT)
> >> +		return led_cdev;
> >> +
> >>  	mutex_lock(&leds_lookup_lock);
> >>  	list_for_each_entry(lookup, &leds_lookup_list, list) {
> >>  		if (!strcmp(lookup->dev_id, dev_name(dev)) &&
> >>
> >> -- 
> >> 2.48.1
> >>
> >>
> > 
>