[PATCH 4/4] Input: leds - force the LED status after .probe()

From: Benjamin Tissoires
Date: Fri Jan 27 2017 - 12:41:12 EST


Once the host has set the initial setting of the LEDs after a new
USB keyboard gets connected, they appear to have a SET_IDLE command
sent which turns of the LEDs.
This means that the initial step of setting the LEDs on a keyboard is
just reset once .probe() finishes.
To be sure we set the LEDs, start a delayed task to try to resend
them after 1 sec.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/input/input-leds.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/drivers/input/input-leds.c b/drivers/input/input-leds.c
index 766bf26..83d930f 100644
--- a/drivers/input/input-leds.c
+++ b/drivers/input/input-leds.c
@@ -46,6 +46,7 @@ struct input_led {

struct input_leds {
struct input_handle handle;
+ struct delayed_work init_work;
unsigned int num_leds;
struct input_led leds[];
};
@@ -83,6 +84,33 @@ static int input_leds_get_count(struct input_dev *dev)
return count;
}

+#ifdef CONFIG_LEDS_TRIGGERS
+static void leds_init_work(struct work_struct *work)
+{
+ struct input_leds *leds = container_of(work, struct input_leds,
+ init_work.work);
+ struct input_led *led;
+ unsigned int led_code;
+ int led_no = 0;
+
+ for_each_set_bit(led_code, leds->handle.dev->ledbit, LED_CNT) {
+ led = &leds->leds[led_no];
+
+ down_read(&led->cdev.trigger_lock);
+ if (led->cdev.trigger && led->cdev.trigger->activate) {
+ led_set_brightness(&led->cdev, LED_OFF);
+ led->cdev.trigger->activate(&led->cdev);
+ }
+ up_read(&led->cdev.trigger_lock);
+ led_no++;
+ }
+}
+#else /* !CONFIG_LEDS_TRIGGERS */
+static void leds_init_work(struct work_struct *work)
+{
+}
+#endif
+
static int input_leds_connect(struct input_handler *handler,
struct input_dev *dev,
const struct input_device_id *id)
@@ -108,6 +136,7 @@ static int input_leds_connect(struct input_handler *handler,
leds->handle.handler = handler;
leds->handle.name = "leds";
leds->handle.private = leds;
+ INIT_DELAYED_WORK(&leds->init_work, leds_init_work);

error = input_register_handle(&leds->handle);
if (error)
@@ -151,6 +180,8 @@ static int input_leds_connect(struct input_handler *handler,
led_no++;
}

+ schedule_delayed_work(&leds->init_work, msecs_to_jiffies(1000));
+
return 0;

err_unregister_leds:
@@ -176,6 +207,8 @@ static void input_leds_disconnect(struct input_handle *handle)
struct input_leds *leds = handle->private;
int i;

+ cancel_delayed_work_sync(&leds->init_work);
+
for (i = 0; i < leds->num_leds; i++) {
struct input_led *led = &leds->leds[i];

--
2.9.3