In some hardware there are 1 or more LEDs behind the touchscreen
softbuttons, which are intended to provide visual feedback to the
user that the softbutton has been pressed, this commit adds support
for this.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
.../bindings/input/touchscreen/softbuttons.txt | 4 ++
drivers/input/touchscreen/softbuttons.c | 49 +++++++++++++++++++++-
2 files changed, 52 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/softbuttons.txt b/Documentation/devicetree/bindings/input/touchscreen/softbuttons.txt
index 3eb6f4c..b425b95 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/softbuttons.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/softbuttons.txt
@@ -17,6 +17,10 @@ Required subnode-properties:
- softbutton-min-y : Y start of the area the softbutton area covers
- softbutton-max-y : Y end of the area the softbutton area covers
+Optional subnode-properties:
+- linux,led-trigger : String for a LED trigger for providing visual
+ feedback that the softbutton has been pressed
+
Example:
#include <dt-bindings/input/input.h>
diff --git a/drivers/input/touchscreen/softbuttons.c b/drivers/input/touchscreen/softbuttons.c
index 47aea18..9a3fbfa 100644
--- a/drivers/input/touchscreen/softbuttons.c
+++ b/drivers/input/touchscreen/softbuttons.c
@@ -11,6 +11,7 @@
#include <linux/input.h>
#include <linux/input/touchscreen.h>
+#include <linux/leds.h>
#include <linux/of.h>
struct touchscreen_softbutton {
@@ -19,6 +20,8 @@ struct touchscreen_softbutton {
u32 min_y;
u32 max_y;
u32 keycode;
+ const char *ledtrigger_name;
+ struct led_trigger *ledtrigger;
};
struct touchscreen_softbutton_info {
@@ -48,7 +51,7 @@ struct touchscreen_softbutton_info *devm_touchscreen_alloc_softbuttons(
struct device *dev = input->dev.parent;
struct device_node *np, *pp;
struct touchscreen_softbutton_info *info;
- int i, err, button_count;
+ int i, j, err, button_count;
np = dev->of_node;
if (!np)
@@ -103,6 +106,36 @@ struct touchscreen_softbutton_info *devm_touchscreen_alloc_softbuttons(
dev_err(dev, "%s: Inval max-y prop\n", pp->name);
return ERR_PTR(-EINVAL);
}
+
+ err = of_property_read_string(pp, "linux,led-trigger",
+ &btn->ledtrigger_name);
+ if (err)
+ continue; /* The LED trigger is optional */
+
+ /* Check if another softbutton uses the same trigger */
+ for (j = 0; j < i; j++) {
+ if (info->buttons[j].ledtrigger_name &&
+ strcmp(info->buttons[j].ledtrigger_name,
+ btn->ledtrigger_name) == 0) {
+ btn->ledtrigger = info->buttons[j].ledtrigger;
+ break;
+ }
+ }
+ if (!btn->ledtrigger) {
+ btn->ledtrigger =
+ devm_kzalloc(dev, sizeof(*btn->ledtrigger),
+ GFP_KERNEL);
+ if (!btn->ledtrigger)
+ return ERR_PTR(-ENOMEM);
+
+ btn->ledtrigger->name = btn->ledtrigger_name;
+ err = devm_led_trigger_register(dev, btn->ledtrigger);
+ if (err) {
+ dev_err(dev, "%s: Ledtrigger register error\n",
+ pp->name);
+ return ERR_PTR(err);
+ }
+ }
}
__set_bit(EV_KEY, input->evbit);
@@ -126,6 +159,7 @@ bool touchscreen_handle_softbuttons(struct touchscreen_softbutton_info *info,
unsigned int x, unsigned int y, bool down)
{
int i;
+ unsigned long led_delay = 1000; /* Keep the led on 1s after release */
if (info == NULL)
return false;
@@ -137,6 +171,19 @@ bool touchscreen_handle_softbuttons(struct touchscreen_softbutton_info *info,
y <= info->buttons[i].max_y) {
input_report_key(info->input,
info->buttons[i].keycode, down);
+
+ if (info->buttons[i].ledtrigger && down) {
+ led_trigger_event(info->buttons[i].ledtrigger,
+ LED_FULL);
+ } else if (info->buttons[i].ledtrigger && !down) {
+ /* Led must be off before calling blink */
+ led_trigger_event(info->buttons[i].ledtrigger,
+ LED_OFF);
+ led_trigger_blink_oneshot(
+ info->buttons[i].ledtrigger,
+ &led_delay, &led_delay, 0);
+ }
+
return true;
}
}
--
2.7.4
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