mediatek: add support for reset gpio

Some versions of the ledbar MCU have a reset pin. It needs to be
correctly initialized or we might keep the MCU in reset state.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
(cherry picked from commit 84e4bbf5f049cdb862eb25c446bd6973ed4238aa)

diff --git a/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c b/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
index c62e233e6d385e22ebab480d22dddc9b7ffac05f..1d687b76861c6f53523def44665ba3642ef9eec0 100644 (file)
--- a/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
+++ b/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
@@ -39,6 +39,7 @@ struct ubnt_ledbar {
        struct led_classdev led_green;
        struct led_classdev led_blue;
        struct gpio_desc *enable_gpio;
+       struct gpio_desc *reset_gpio;
 };
 
 static void ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
@@ -96,6 +97,20 @@ out_gpio:
        return ret;
 }
 
+static void ubnt_ledbar_reset(struct ubnt_ledbar *ledbar)
+{
+       if (!ledbar->reset_gpio)
+               return;
+
+       mutex_lock(&ledbar->lock);
+
+       gpiod_set_value(ledbar->reset_gpio, 1);
+       msleep(10);
+       gpiod_set_value(ledbar->reset_gpio, 0);
+
+       mutex_unlock(&ledbar->lock);
+}
+
 #define UBNT_LEDBAR_CONTROL_RGBS(name)                         \
 static int ubnt_ledbar_set_##name##_brightness(struct led_classdev *led_cdev,\
                                        enum led_brightness value)      \
@@ -154,12 +169,23 @@ static int ubnt_ledbar_probe(struct i2c_client *client,
                return ret;
        }
 
+       ledbar->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
+
+       if (IS_ERR(ledbar->reset_gpio)) {
+               ret = PTR_ERR(ledbar->reset_gpio);
+               dev_err(&client->dev, "Failed to get reset gpio: %d\n", ret);
+               return ret;
+       }
+
        ledbar->client = client;
 
        mutex_init(&ledbar->lock);
 
        i2c_set_clientdata(client, ledbar);
 
+       // Reset and initialize the MCU
+       ubnt_ledbar_reset(ledbar);
+
        ledbar->led_red.brightness_set_blocking = ubnt_ledbar_set_red_brightness;
        ubnt_ledbar_init_led(of_get_child_by_name(np, "red"), ledbar, &ledbar->led_red);