[PATCH 0/3] power: supply: power-supply-leds: Add activate() callback to triggers

[PATCH 0/3] power: supply: power-supply-leds: Add activate() callback to triggers

[Hans de Goede]

Hi All,

This series adds an activate callback to the power-supply LED triggers to
ensure that power-supply LEDs get the correct initial value when the LED
gets registered after the power_supply has been registered.

Patches 1-2 do some refactoring / prep work and patch 3 adds the actual
activate callback.

This series applies on top of "[PATCH v9 6/7] power: supply: power-supply-leds:
Add charging_orange_full_green trigger for RGB LED":
https://lore.kernel.org/all/20240504164105.114017-7-hdegoede@redhat.com/

Regards,

Hans


Hans de Goede (3):
  power: supply: power-supply-leds: Add
    power_supply_[un]register_led_trigger()
  power: supply: power-supply-leds: Share trig pointer for online and
    charging_full
  power: supply: power-supply-leds: Add activate() callback to triggers

 drivers/power/supply/power_supply_leds.c | 176 +++++++++++++----------
 include/linux/power_supply.h             |   9 +-
 2 files changed, 101 insertions(+), 84 deletions(-)

-- 
2.44.0

[PATCH 1/3] power: supply: power-supply-leds: Add power_supply_[un]register_led_trigger()

[Hans de Goede]

Add power_supply_[un]register_led_trigger() helper functions.

The primary goal of this is as a preparation patch for adding an activate
callback to the power-supply LED triggers to ensure that power-supply
LEDs get the correct initial value when the LED gets registered after
the power_supply has been registered (this will use the psy back pointer).

There also is quite a lot of code duplication in the existing LED trigger
registration in the form of the kasprintf() for the name-template for each
trigger + related error handling. This duplication is removed by these
new helpers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/power/supply/power_supply_leds.c | 155 ++++++++++++-----------
 include/linux/power_supply.h             |   6 -
 2 files changed, 84 insertions(+), 77 deletions(-)

diff --git a/drivers/power/supply/power_supply_leds.c b/drivers/power/supply/power_supply_leds.c
index 73935de844d9..3e20b0f30aa3 100644
--- a/drivers/power/supply/power_supply_leds.c
+++ b/drivers/power/supply/power_supply_leds.c
@@ -19,6 +19,57 @@
 
 /* Battery specific LEDs triggers. */
 
+struct power_supply_led_trigger {
+	struct led_trigger trig;
+	struct power_supply *psy;
+};
+
+static int power_supply_register_led_trigger(struct power_supply *psy,
+					     const char *name_template,
+					     struct led_trigger **tp)
+{
+	struct power_supply_led_trigger *psy_trig;
+	int err;
+
+	psy_trig = kzalloc(sizeof(*psy_trig), GFP_KERNEL);
+	if (!psy_trig)
+		return -ENOMEM;
+
+	psy_trig->trig.name = kasprintf(GFP_KERNEL, name_template, psy->desc->name);
+	if (!psy_trig->trig.name) {
+		err = -ENOMEM;
+		goto err_free_trigger;
+	}
+
+	psy_trig->psy = psy;
+
+	err = led_trigger_register(&psy_trig->trig);
+	if (err)
+		goto err_free_name;
+
+	*tp = &psy_trig->trig;
+	return 0;
+
+err_free_name:
+	kfree(psy_trig->trig.name);
+err_free_trigger:
+	kfree(psy_trig);
+	return -ENOMEM;
+}
+
+static void power_supply_unregister_led_trigger(struct led_trigger *trig)
+{
+	struct power_supply_led_trigger *psy_trig;
+
+	if (!trig)
+		return;
+
+	psy_trig = container_of(trig, struct power_supply_led_trigger, trig);
+	led_trigger_unregister(&psy_trig->trig);
+	kfree(psy_trig->trig.name);
+	kfree(psy_trig);
+}
+
 static void power_supply_update_bat_leds(struct power_supply *psy)
 {
 	union power_supply_propval status;
@@ -65,69 +116,39 @@ static void power_supply_update_bat_leds(struct power_supply *psy)
 	}
 }
 
-static int power_supply_create_bat_triggers(struct power_supply *psy)
-{
-	psy->charging_full_trig_name = kasprintf(GFP_KERNEL,
-					"%s-charging-or-full", psy->desc->name);
-	if (!psy->charging_full_trig_name)
-		goto charging_full_failed;
-
-	psy->charging_trig_name = kasprintf(GFP_KERNEL,
-					"%s-charging", psy->desc->name);
-	if (!psy->charging_trig_name)
-		goto charging_failed;
-
-	psy->full_trig_name = kasprintf(GFP_KERNEL, "%s-full", psy->desc->name);
-	if (!psy->full_trig_name)
-		goto full_failed;
-
-	psy->charging_blink_full_solid_trig_name = kasprintf(GFP_KERNEL,
-		"%s-charging-blink-full-solid", psy->desc->name);
-	if (!psy->charging_blink_full_solid_trig_name)
-		goto charging_blink_full_solid_failed;
-
-	psy->charging_orange_full_green_trig_name = kasprintf(GFP_KERNEL,
-		"%s-charging-orange-full-green", psy->desc->name);
-	if (!psy->charging_orange_full_green_trig_name)
-		goto charging_red_full_green_failed;
-
-	led_trigger_register_simple(psy->charging_full_trig_name,
-				    &psy->charging_full_trig);
-	led_trigger_register_simple(psy->charging_trig_name,
-				    &psy->charging_trig);
-	led_trigger_register_simple(psy->full_trig_name,
-				    &psy->full_trig);
-	led_trigger_register_simple(psy->charging_blink_full_solid_trig_name,
-				    &psy->charging_blink_full_solid_trig);
-	led_trigger_register_simple(psy->charging_orange_full_green_trig_name,
-				    &psy->charging_orange_full_green_trig);
-
-	return 0;
-
-charging_red_full_green_failed:
-	kfree(psy->charging_blink_full_solid_trig_name);
-charging_blink_full_solid_failed:
-	kfree(psy->full_trig_name);
-full_failed:
-	kfree(psy->charging_trig_name);
-charging_failed:
-	kfree(psy->charging_full_trig_name);
-charging_full_failed:
-	return -ENOMEM;
-}
-
 static void power_supply_remove_bat_triggers(struct power_supply *psy)
 {
-	led_trigger_unregister_simple(psy->charging_full_trig);
-	led_trigger_unregister_simple(psy->charging_trig);
-	led_trigger_unregister_simple(psy->full_trig);
-	led_trigger_unregister_simple(psy->charging_blink_full_solid_trig);
-	led_trigger_unregister_simple(psy->charging_orange_full_green_trig);
-	kfree(psy->charging_blink_full_solid_trig_name);
-	kfree(psy->full_trig_name);
-	kfree(psy->charging_trig_name);
-	kfree(psy->charging_full_trig_name);
-	kfree(psy->charging_orange_full_green_trig_name);
+	power_supply_unregister_led_trigger(psy->charging_full_trig);
+	power_supply_unregister_led_trigger(psy->charging_trig);
+	power_supply_unregister_led_trigger(psy->full_trig);
+	power_supply_unregister_led_trigger(psy->charging_blink_full_solid_trig);
+	power_supply_unregister_led_trigger(psy->charging_orange_full_green_trig);
+}
+
+static int power_supply_create_bat_triggers(struct power_supply *psy)
+{
+	int err = 0;
+
+	err |= power_supply_register_led_trigger(psy, "%s-charging-or-full",
+						 &psy->charging_full_trig);
+	err |= power_supply_register_led_trigger(psy, "%s-charging",
+						 &psy->charging_trig);
+	err |= power_supply_register_led_trigger(psy, "%s-full",
+						 &psy->full_trig);
+	err |= power_supply_register_led_trigger(psy, "%s-charging-blink-full-solid",
+						 &psy->charging_blink_full_solid_trig);
+	err |= power_supply_register_led_trigger(psy, "%s-charging-orange-full-green",
+						 &psy->charging_orange_full_green_trig);
+	if (err) {
+		power_supply_remove_bat_triggers(psy);
+		/*
+		 * led_trigger_register() may also return -EEXIST but that should
+		 * never happen with the dynamically generated psy trigger names.
+		 */
+		return -ENOMEM;
+	}
+
+	return 0;
 }
 
 /* Generated power specific LEDs triggers. */
@@ -149,20 +170,12 @@ static void power_supply_update_gen_leds(struct power_supply *psy)
 
 static int power_supply_create_gen_triggers(struct power_supply *psy)
 {
-	psy->online_trig_name = kasprintf(GFP_KERNEL, "%s-online",
-					  psy->desc->name);
-	if (!psy->online_trig_name)
-		return -ENOMEM;
-
-	led_trigger_register_simple(psy->online_trig_name, &psy->online_trig);
-
-	return 0;
+	return power_supply_register_led_trigger(psy, "%s-online", &psy->online_trig);
 }
 
 static void power_supply_remove_gen_triggers(struct power_supply *psy)
 {
-	led_trigger_unregister_simple(psy->online_trig);
-	kfree(psy->online_trig_name);
+	power_supply_unregister_led_trigger(psy->online_trig);
 }
 
 /* Choice what triggers to create&update. */
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index c852cc882501..e218a8ab72ee 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -310,17 +310,11 @@ struct power_supply {
 
 #ifdef CONFIG_LEDS_TRIGGERS
 	struct led_trigger *charging_full_trig;
-	char *charging_full_trig_name;
 	struct led_trigger *charging_trig;
-	char *charging_trig_name;
 	struct led_trigger *full_trig;
-	char *full_trig_name;
 	struct led_trigger *online_trig;
-	char *online_trig_name;
 	struct led_trigger *charging_blink_full_solid_trig;
-	char *charging_blink_full_solid_trig_name;
 	struct led_trigger *charging_orange_full_green_trig;
-	char *charging_orange_full_green_trig_name;
 #endif
 };
 
-- 
2.44.0

[PATCH 2/3] power: supply: power-supply-leds: Share trig pointer for online and charging_full

[Hans de Goede]

Either 5 different LED triggers are registered for battery power-supply
devices or a single online LED trigger is used for non battery power-supply
devices.

These 5 / 1 LED trigger(s) are never used at the same time. So there is
no need for a separate LED trigger pointer for the online trigger. Rename
the first battery trigger from charging_full_trig to just trig and use this
for the online trigger too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/power/supply/power_supply_leds.c | 18 +++++++++---------
 include/linux/power_supply.h             |  3 +--
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/power/supply/power_supply_leds.c b/drivers/power/supply/power_supply_leds.c
index 3e20b0f30aa3..634f7d33afd0 100644
--- a/drivers/power/supply/power_supply_leds.c
+++ b/drivers/power/supply/power_supply_leds.c
@@ -83,7 +83,7 @@ static void power_supply_update_bat_leds(struct power_supply *psy)
 
 	switch (status.intval) {
 	case POWER_SUPPLY_STATUS_FULL:
-		led_trigger_event(psy->charging_full_trig, LED_FULL);
+		led_trigger_event(psy->trig, LED_FULL);
 		led_trigger_event(psy->charging_trig, LED_OFF);
 		led_trigger_event(psy->full_trig, LED_FULL);
 		/* Going from blink to LED on requires a LED_OFF event to stop blink */
@@ -95,7 +95,7 @@ static void power_supply_update_bat_leds(struct power_supply *psy)
 				     LED_FULL);
 		break;
 	case POWER_SUPPLY_STATUS_CHARGING:
-		led_trigger_event(psy->charging_full_trig, LED_FULL);
+		led_trigger_event(psy->trig, LED_FULL);
 		led_trigger_event(psy->charging_trig, LED_FULL);
 		led_trigger_event(psy->full_trig, LED_OFF);
 		led_trigger_blink(psy->charging_blink_full_solid_trig, 0, 0);
@@ -105,7 +105,7 @@ static void power_supply_update_bat_leds(struct power_supply *psy)
 				     LED_FULL);
 		break;
 	default:
-		led_trigger_event(psy->charging_full_trig, LED_OFF);
+		led_trigger_event(psy->trig, LED_OFF);
 		led_trigger_event(psy->charging_trig, LED_OFF);
 		led_trigger_event(psy->full_trig, LED_OFF);
 		led_trigger_event(psy->charging_blink_full_solid_trig,
@@ -118,7 +118,7 @@ static void power_supply_update_bat_leds(struct power_supply *psy)
 
 static void power_supply_remove_bat_triggers(struct power_supply *psy)
 {
-	power_supply_unregister_led_trigger(psy->charging_full_trig);
+	power_supply_unregister_led_trigger(psy->trig);
 	power_supply_unregister_led_trigger(psy->charging_trig);
 	power_supply_unregister_led_trigger(psy->full_trig);
 	power_supply_unregister_led_trigger(psy->charging_blink_full_solid_trig);
@@ -130,7 +130,7 @@ static int power_supply_create_bat_triggers(struct power_supply *psy)
 	int err = 0;
 
 	err |= power_supply_register_led_trigger(psy, "%s-charging-or-full",
-						 &psy->charging_full_trig);
+						 &psy->trig);
 	err |= power_supply_register_led_trigger(psy, "%s-charging",
 						 &psy->charging_trig);
 	err |= power_supply_register_led_trigger(psy, "%s-full",
@@ -163,19 +163,19 @@ static void power_supply_update_gen_leds(struct power_supply *psy)
 	dev_dbg(&psy->dev, "%s %d\n", __func__, online.intval);
 
 	if (online.intval)
-		led_trigger_event(psy->online_trig, LED_FULL);
+		led_trigger_event(psy->trig, LED_FULL);
 	else
-		led_trigger_event(psy->online_trig, LED_OFF);
+		led_trigger_event(psy->trig, LED_OFF);
 }
 
 static int power_supply_create_gen_triggers(struct power_supply *psy)
 {
-	return power_supply_register_led_trigger(psy, "%s-online", &psy->online_trig);
+	return power_supply_register_led_trigger(psy, "%s-online", &psy->trig);
 }
 
 static void power_supply_remove_gen_triggers(struct power_supply *psy)
 {
-	power_supply_unregister_led_trigger(psy->online_trig);
+	power_supply_unregister_led_trigger(psy->trig);
 }
 
 /* Choice what triggers to create&update. */
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index e218a8ab72ee..65082ef75692 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -309,10 +309,9 @@ struct power_supply {
 #endif
 
 #ifdef CONFIG_LEDS_TRIGGERS
-	struct led_trigger *charging_full_trig;
+	struct led_trigger *trig;
 	struct led_trigger *charging_trig;
 	struct led_trigger *full_trig;
-	struct led_trigger *online_trig;
 	struct led_trigger *charging_blink_full_solid_trig;
 	struct led_trigger *charging_orange_full_green_trig;
 #endif
-- 
2.44.0

[PATCH 3/3] power: supply: power-supply-leds: Add activate() callback to triggers

[Hans de Goede]

Add an activate() callback to the power-supply LED triggers so that
the LED being activated will properly reflect the current power-supply
state for power-supply devices which are already fully registered
when the trigger gets activated.

This fixes e.g. wrong LED state (1) when the LED gets registered
after the power-supply device.

1) Until the psy driver has a reason to call power_supply_changed()
   which may take quite a while

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/power/supply/power_supply_leds.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/power/supply/power_supply_leds.c b/drivers/power/supply/power_supply_leds.c
index 634f7d33afd0..7ff6d41671b9 100644
--- a/drivers/power/supply/power_supply_leds.c
+++ b/drivers/power/supply/power_supply_leds.c
@@ -24,6 +24,16 @@ struct power_supply_led_trigger {
 	struct power_supply *psy;
 };
 
+static int power_supply_led_trigger_activate(struct led_classdev *led_cdev)
+{
+	struct power_supply_led_trigger *psy_trig =
+		container_of(led_cdev->trigger, struct power_supply_led_trigger, trig);
+
+	/* Sync current power-supply state to LED being activated */
+	power_supply_update_leds(psy_trig->psy);
+	return 0;
+}
+
 static int power_supply_register_led_trigger(struct power_supply *psy,
 					     const char *name_template,
 					     struct led_trigger **tp)
@@ -41,6 +51,7 @@ static int power_supply_register_led_trigger(struct power_supply *psy,
 		goto err_free_trigger;
 	}
 
+	psy_trig->trig.activate = power_supply_led_trigger_activate;
 	psy_trig->psy = psy;
 
 	err = led_trigger_register(&psy_trig->trig);
-- 
2.44.0

Re: [PATCH 1/3] power: supply: power-supply-leds: Add power_supply_[un]register_led_trigger()

[Andy Shevchenko]

On Fri, May 10, 2024 at 09:40:10PM +0200, Hans de Goede wrote:
> Add power_supply_[un]register_led_trigger() helper functions.
> 
> The primary goal of this is as a preparation patch for adding an activate
> callback to the power-supply LED triggers to ensure that power-supply
> LEDs get the correct initial value when the LED gets registered after
> the power_supply has been registered (this will use the psy back pointer).
> 
> There also is quite a lot of code duplication in the existing LED trigger
> registration in the form of the kasprintf() for the name-template for each
> trigger + related error handling. This duplication is removed by these
> new helpers.

...

> +	err = led_trigger_register(&psy_trig->trig);
> +	if (err)
> +		goto err_free_name;


> +err_free_name:
> +	kfree(psy_trig->trig.name);
> +err_free_trigger:
> +	kfree(psy_trig);
> +	return -ENOMEM;

Why not ret?

...

> +static int power_supply_create_bat_triggers(struct power_supply *psy)
> +{
> +	int err = 0;
> +
> +	err |= power_supply_register_led_trigger(psy, "%s-charging-or-full",
> +						 &psy->charging_full_trig);
> +	err |= power_supply_register_led_trigger(psy, "%s-charging",
> +						 &psy->charging_trig);
> +	err |= power_supply_register_led_trigger(psy, "%s-full",
> +						 &psy->full_trig);
> +	err |= power_supply_register_led_trigger(psy, "%s-charging-blink-full-solid",
> +						 &psy->charging_blink_full_solid_trig);
> +	err |= power_supply_register_led_trigger(psy, "%s-charging-orange-full-green",
> +						 &psy->charging_orange_full_green_trig);

Why not using the similar approach as you have done in v4l2 CCI?

> +	if (err) {
> +		power_supply_remove_bat_triggers(psy);
> +		/*
> +		 * led_trigger_register() may also return -EEXIST but that should
> +		 * never happen with the dynamically generated psy trigger names.
> +		 */

Maybe this comment should be above and here just return err; (but see above remark).

> +		return -ENOMEM;
> +	}
> +
> +	return 0;
>  }

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 3/3] power: supply: power-supply-leds: Add activate() callback to triggers

[Andy Shevchenko]

On Fri, May 10, 2024 at 09:40:12PM +0200, Hans de Goede wrote:
> Add an activate() callback to the power-supply LED triggers so that
> the LED being activated will properly reflect the current power-supply
> state for power-supply devices which are already fully registered
> when the trigger gets activated.
> 
> This fixes e.g. wrong LED state (1) when the LED gets registered
> after the power-supply device.
> 
> 1) Until the psy driver has a reason to call power_supply_changed()
>    which may take quite a while

...

> +static int power_supply_led_trigger_activate(struct led_classdev *led_cdev)
> +{
> +	struct power_supply_led_trigger *psy_trig =
> +		container_of(led_cdev->trigger, struct power_supply_led_trigger, trig);

Second time same container_of(), perhaps a helper [macro]?

> +	/* Sync current power-supply state to LED being activated */
> +	power_supply_update_leds(psy_trig->psy);
> +	return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko