* [PATCH] leds: trigger: Add invert attribute to ledtrig-audio
@ 2021-08-09 12:29 Phil Sutter
2021-08-09 18:11 ` Pavel Machek
0 siblings, 1 reply; 4+ messages in thread
From: Phil Sutter @ 2021-08-09 12:29 UTC (permalink / raw)
To: Pavel Machek; +Cc: linux-leds
Inverting micmute LED used to be possible via a mixer setting, but
conversion to LEDs class (probably) killed it. Re-establish the old
functionality via sysfs attribute in audio LED triggers.
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
drivers/leds/trigger/ledtrig-audio.c | 106 ++++++++++++++++++++++++++-
1 file changed, 102 insertions(+), 4 deletions(-)
diff --git a/drivers/leds/trigger/ledtrig-audio.c b/drivers/leds/trigger/ledtrig-audio.c
index f76621e88482d..319ac4f514dfd 100644
--- a/drivers/leds/trigger/ledtrig-audio.c
+++ b/drivers/leds/trigger/ledtrig-audio.c
@@ -6,9 +6,12 @@
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
static struct led_trigger *ledtrig_audio[NUM_AUDIO_LEDS];
static enum led_brightness audio_state[NUM_AUDIO_LEDS];
+static bool led_invert[NUM_AUDIO_LEDS];
enum led_brightness ledtrig_audio_get(enum led_audio type)
{
@@ -18,17 +21,112 @@ EXPORT_SYMBOL_GPL(ledtrig_audio_get);
void ledtrig_audio_set(enum led_audio type, enum led_brightness state)
{
+ if (led_invert[type])
+ state = !state;
+
audio_state[type] = state;
led_trigger_event(ledtrig_audio[type], state);
}
EXPORT_SYMBOL_GPL(ledtrig_audio_set);
+static ssize_t do_invert_show(enum led_audio type, char *buf)
+{
+ return sprintf(buf, "%u\n", led_invert[type]);
+}
+
+static ssize_t mute_invert_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return do_invert_show(LED_AUDIO_MUTE, buf);
+}
+
+static ssize_t micmute_invert_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return do_invert_show(LED_AUDIO_MICMUTE, buf);
+}
+
+static ssize_t do_invert_store(enum led_audio type,
+ const char *buf, size_t size)
+{
+ unsigned long state;
+ int ret;
+
+ ret = kstrtoul(buf, 0, &state);
+ if (ret)
+ return ret;
+
+ led_invert[type] = !!state;
+ ledtrig_audio_set(type, audio_state[type]);
+
+ return size;
+}
+
+static ssize_t mute_invert_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ return do_invert_store(LED_AUDIO_MUTE, buf, size);
+}
+
+static ssize_t micmute_invert_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ return do_invert_store(LED_AUDIO_MICMUTE, buf, size);
+}
+
+static struct device_attribute dev_attr_mute_invert =
+ __ATTR(invert, 0644, mute_invert_show, mute_invert_store);
+
+static struct attribute *audio_mute_trig_attrs[] = {
+ &dev_attr_mute_invert.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(audio_mute_trig);
+
+static struct device_attribute dev_attr_micmute_invert =
+ __ATTR(invert, 0644, micmute_invert_show, micmute_invert_store);
+
+static struct attribute *audio_micmute_trig_attrs[] = {
+ &dev_attr_micmute_invert.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(audio_micmute_trig);
+
+static void __init do_ledtrig_audio_init(const char *name,
+ enum led_audio type,
+ const struct attribute_group **groups)
+{
+ struct led_trigger *trigger;
+ int err;
+
+ trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
+ if (!trigger) {
+ pr_warn("LED trigger %s failed to register (no memory)\n",
+ name);
+ goto out;
+ }
+
+ trigger->name = name;
+ trigger->groups = groups;
+
+ err = led_trigger_register(trigger);
+ if (err < 0) {
+ kfree(trigger);
+ trigger = NULL;
+ pr_warn("LED trigger %s failed to register (%d)\n", name, err);
+ }
+out:
+ ledtrig_audio[type] = trigger;
+}
+
static int __init ledtrig_audio_init(void)
{
- led_trigger_register_simple("audio-mute",
- &ledtrig_audio[LED_AUDIO_MUTE]);
- led_trigger_register_simple("audio-micmute",
- &ledtrig_audio[LED_AUDIO_MICMUTE]);
+ do_ledtrig_audio_init("audio-mute", LED_AUDIO_MUTE,
+ audio_mute_trig_groups);
+ do_ledtrig_audio_init("audio-micmute", LED_AUDIO_MICMUTE,
+ audio_micmute_trig_groups);
return 0;
}
module_init(ledtrig_audio_init);
--
2.32.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] leds: trigger: Add invert attribute to ledtrig-audio
2021-08-09 12:29 [PATCH] leds: trigger: Add invert attribute to ledtrig-audio Phil Sutter
@ 2021-08-09 18:11 ` Pavel Machek
2021-08-10 9:22 ` Phil Sutter
0 siblings, 1 reply; 4+ messages in thread
From: Pavel Machek @ 2021-08-09 18:11 UTC (permalink / raw)
To: Phil Sutter; +Cc: linux-leds
[-- Attachment #1: Type: text/plain, Size: 982 bytes --]
Hi!
> Inverting micmute LED used to be possible via a mixer setting, but
> conversion to LEDs class (probably) killed it. Re-establish the old
> functionality via sysfs attribute in audio LED triggers.
So we have both invert and inverted attributes. Fun :-).
See sysfs-class-led and sysfs-class-led-trigger-oneshot.
We definitely want this documented. We probably want this for most
triggers, maybe it should get one implementation in library somewhere?
Otherwise it makes sense.
> +static ssize_t do_invert_store(enum led_audio type,
> + const char *buf, size_t size)
> +{
> + unsigned long state;
> + int ret;
> +
> + ret = kstrtoul(buf, 0, &state);
> + if (ret)
> + return ret;
> +
> + led_invert[type] = !!state;
> + ledtrig_audio_set(type, audio_state[type]);
Accepting 42 as valid value sounds wrong. Anyway, this should do what
oneshot trigger does.
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] leds: trigger: Add invert attribute to ledtrig-audio
2021-08-09 18:11 ` Pavel Machek
@ 2021-08-10 9:22 ` Phil Sutter
2021-08-10 13:52 ` Pavel Machek
0 siblings, 1 reply; 4+ messages in thread
From: Phil Sutter @ 2021-08-10 9:22 UTC (permalink / raw)
To: Pavel Machek; +Cc: linux-leds
Hi Pavel,
On Mon, Aug 09, 2021 at 08:11:18PM +0200, Pavel Machek wrote:
> > Inverting micmute LED used to be possible via a mixer setting, but
> > conversion to LEDs class (probably) killed it. Re-establish the old
> > functionality via sysfs attribute in audio LED triggers.
>
> So we have both invert and inverted attributes. Fun :-).
Hmm! :)
Are you talking about LED_BLINK_INVERT flag? I see a few triggers allow
inversion but didn't find LED drivers exporting such a property.
> See sysfs-class-led and sysfs-class-led-trigger-oneshot.
I think I "copied" from oneshot trigger when writing this patch.
> We definitely want this documented. We probably want this for most
> triggers, maybe it should get one implementation in library somewhere?
Should this be an implicit attribute of simple triggers only or all? In
the latter case (which could simplify some triggers) I guess the value
inversion has to take place in led_set_brightness_nopm(), the lowest
level function triggers may use.
How does inversion work, actually? LED_OFF <-> LED_ON is trivial, but
what about LED_HALF and LED_FULL? Leaving LED_HALF as-is seems logical,
but the opposite of LED_OFF might be LED_ON or LED_FULL. Does
max_brightness determine that?
>
> Otherwise it makes sense.
>
> > +static ssize_t do_invert_store(enum led_audio type,
> > + const char *buf, size_t size)
> > +{
> > + unsigned long state;
> > + int ret;
> > +
> > + ret = kstrtoul(buf, 0, &state);
> > + if (ret)
> > + return ret;
> > +
> > + led_invert[type] = !!state;
> > + ledtrig_audio_set(type, audio_state[type]);
>
> Accepting 42 as valid value sounds wrong. Anyway, this should do what
> oneshot trigger does.
Similarities to oneshot are not a coincidence. :)
Cheers, Phil
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] leds: trigger: Add invert attribute to ledtrig-audio
2021-08-10 9:22 ` Phil Sutter
@ 2021-08-10 13:52 ` Pavel Machek
0 siblings, 0 replies; 4+ messages in thread
From: Pavel Machek @ 2021-08-10 13:52 UTC (permalink / raw)
To: Phil Sutter; +Cc: linux-leds
[-- Attachment #1: Type: text/plain, Size: 1630 bytes --]
Hi!
>
> On Mon, Aug 09, 2021 at 08:11:18PM +0200, Pavel Machek wrote:
> > > Inverting micmute LED used to be possible via a mixer setting, but
> > > conversion to LEDs class (probably) killed it. Re-establish the old
> > > functionality via sysfs attribute in audio LED triggers.
> >
> > So we have both invert and inverted attributes. Fun :-).
>
> Hmm! :)
>
> Are you talking about LED_BLINK_INVERT flag? I see a few triggers allow
> inversion but didn't find LED drivers exporting such a property.
>
> > See sysfs-class-led and sysfs-class-led-trigger-oneshot.
>
> I think I "copied" from oneshot trigger when writing this patch.
>
> > We definitely want this documented. We probably want this for most
> > triggers, maybe it should get one implementation in library somewhere?
>
> Should this be an implicit attribute of simple triggers only or all? In
> the latter case (which could simplify some triggers) I guess the value
> inversion has to take place in led_set_brightness_nopm(), the lowest
> level function triggers may use.
Actual inversion is trivial (so it may not make sense to share), but
sysfs interface is not. Sharing that would be good.
> How does inversion work, actually? LED_OFF <-> LED_ON is trivial, but
> what about LED_HALF and LED_FULL? Leaving LED_HALF as-is seems logical,
> but the opposite of LED_OFF might be LED_ON or LED_FULL. Does
> max_brightness determine that?
max_brightness determines that, and it would be simply
if (->inverted)
b = ->max_brighntess-b;
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-10 13:52 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-09 12:29 [PATCH] leds: trigger: Add invert attribute to ledtrig-audio Phil Sutter
2021-08-09 18:11 ` Pavel Machek
2021-08-10 9:22 ` Phil Sutter
2021-08-10 13:52 ` Pavel Machek
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.