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/Kconfig | 1 +
drivers/leds/leds-turris-omnia.c | 48 ++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+)
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index fcbe93b61e49..443aaf948bb8 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -219,6 +219,7 @@ config LEDS_TURRIS_OMNIA
depends on OF
depends on TURRIS_OMNIA_MCU
select LEDS_TRIGGERS
+ select TURRIS_OMNIA_MCU_GPIO
help
This option enables basic support for the LEDs found on the front
side of CZ.NIC's Turris Omnia router. There are 12 RGB LEDs on the
diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c
index b13b3b269ae9..ac7938f57bfe 100644
--- a/drivers/leds/leds-turris-omnia.c
+++ b/drivers/leds/leds-turris-omnia.c
@@ -43,12 +43,15 @@ struct omnia_led {
* @client: I2C client device
* @lock: mutex to protect
* @has_gamma_correction: whether the MCU firmware supports gamma correction
+ * @brightness_knode: kernel node of the "brightness" device sysfs attribute (this is the
+ * driver specific global brightness, not the LED classdev brightness)
* @leds: flexible array of per-LED data
*/
struct omnia_leds {
struct i2c_client *client;
struct mutex lock;
bool has_gamma_correction;
+ struct kernfs_node *brightness_knode;
struct omnia_led leds[];
};
@@ -373,6 +376,30 @@ static struct attribute *omnia_led_controller_attrs[] = {
};
ATTRIBUTE_GROUPS(omnia_led_controller);
+static irqreturn_t omnia_brightness_changed_threaded_fn(int irq, void *data)
+{
+ struct omnia_leds *leds = data;
+
+ if (unlikely(!leds->brightness_knode)) {
+ /*
+ * It would be nicer to get this dirent in the driver probe method, before the IRQ
+ * is requested. But the really_probe() function in drivers/base/dd.c registers
+ * driver's .dev_groups only after probe is finished, so during driver probe the
+ * "brightness" sysfs node is not yet present.
+ *
+ * Note that sysfs_get_dirent() may sleep. This is okay, because we are in threaded
+ * context.
+ */
+ leds->brightness_knode = sysfs_get_dirent(leds->client->dev.kobj.sd, "brightness");
+ if (!leds->brightness_knode)
+ return IRQ_NONE;
+ }
+
+ sysfs_notify_dirent(leds->brightness_knode);
+
+ return IRQ_HANDLED;
+}
+
static int omnia_mcu_get_features(const struct i2c_client *client)
{
struct i2c_client mcu_client = *client;
@@ -436,6 +463,14 @@ 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_threaded_irq(dev, client->irq, NULL,
+ omnia_brightness_changed_threaded_fn, 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);
@@ -458,6 +493,19 @@ 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_knode)
+ sysfs_put(leds->brightness_knode);
+
/* 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));
--
2.45.2
