On Fri, 13 Sep 2024, Marek Behún wrote:
> Recall that on Turris Omnia, the LED controller has a global brightness
> property, which allows the user to make the front LED panel dimmer.
>
> There is also a button on the front panel, which by default is
> configured so that pressing it changes the global brightness to a lower
> value (unless it is at 0%, in which case pressing the button changes the
> global brightness to 100%).
>
> Newer versions of the MCU firmware support informing the SOC that the
> brightness was changed by button press event via an interrupt.
>
> Now that we have the turris-omnia-mcu driver, which adds support for MCU
> interrupts, add the ability to inform the userspace (via a sysfs
> notification) that the global brightness was changed.
>
> Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
> ---
> drivers/leds/leds-turris-omnia.c | 37 ++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c
> index 82cf58fbe946..a87cdb58e476 100644
> --- a/drivers/leds/leds-turris-omnia.c
> +++ b/drivers/leds/leds-turris-omnia.c
> @@ -33,6 +33,7 @@ struct omnia_leds {
> struct i2c_client *client;
> struct mutex lock;
> bool has_gamma_correction;
> + struct kernfs_node *brightness_kn;
Variable nomenclature should be self documenting.
What is kn? Please improve this.
> struct omnia_led leds[];
> };
>
> @@ -357,6 +358,21 @@ static struct attribute *omnia_led_controller_attrs[] = {
> };
> ATTRIBUTE_GROUPS(omnia_led_controller);
>
> +static irqreturn_t omnia_brightness_changed_handler(int irq, void *dev_id)
Why dev_id? This appears to be driver data. ddata sounds more applicable.
> +{
> + struct omnia_leds *leds = dev_id;
> +
> + if (unlikely(!leds->brightness_kn)) {
> + leds->brightness_kn = sysfs_get_dirent(leds->client->dev.kobj.sd, "brightness");
NACK. This will sleep in IRQ context.
> + if (!leds->brightness_kn)
> + return IRQ_NONE;
> + }
> +
> + sysfs_notify_dirent(leds->brightness_kn);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int omnia_mcu_get_features(const struct i2c_client *client)
> {
> struct i2c_client mcu_client = *client;
> @@ -420,6 +436,14 @@ static int omnia_leds_probe(struct i2c_client *client)
> "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
> }
>
> + if (ret & OMNIA_FEAT_BRIGHTNESS_INT) {
> + ret = devm_request_any_context_irq(dev, client->irq,
> + omnia_brightness_changed_handler, IRQF_ONESHOT,
> + "leds-turris-omnia", leds);
> + if (ret <= 0)
> + return dev_err_probe(dev, ret ?: -ENXIO, "Cannot request brightness IRQ\n");
> + }
> +
> mutex_init(&leds->lock);
>
> ret = devm_led_trigger_register(dev, &omnia_hw_trigger);
> @@ -442,6 +466,19 @@ static int omnia_leds_probe(struct i2c_client *client)
>
> static void omnia_leds_remove(struct i2c_client *client)
> {
> + struct omnia_leds *leds = i2c_get_clientdata(client);
> +
> + /*
> + * We need to free the brightness IRQ here, before putting away the brightness sysfs node.
> + * Otherwise devres would free the interrupt only after the sysfs node is removed, and if
> + * an interrupt occurred between those two events, it would use a removed sysfs node.
> + */
> + devm_free_irq(&client->dev, client->irq, leds);
> +
> + /* Now put away the sysfs node we got the first time the interrupt handler was called */
> + if (leds->brightness_kn)
> + sysfs_put(leds->brightness_kn);
> +
> /* put all LEDs into default (HW triggered) mode */
> omnia_cmd_write_u8(client, OMNIA_CMD_LED_MODE, OMNIA_CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
>
> --
> 2.44.2
>
--
Lee Jones [李琼斯]
