This change adds support for specifying device tree buttons emitting
abs/rel events.
ABS events were previously supported, but only via platform data, so add
the missing device tree property to allow axis values to be emitted with
abs/rel events.
Also emit 0 on button releases for REL and ABS keys. This is a must-have
for supporting digital joysticks, and aligns the driver whith
gpio-keys-polled.
Finally, report min/max values for abs axes to the input framework.
Signed-off-by: Hans Holmberg <hans@xxxxxxxxxxxxxxxxx>
---
RFC because it alters the behaviour of abs-buttons making them
un-sticky, reporting 0 on button releases - just like gpio-keys-polled.
FWIW, i've looked through the in-tree board files and not found a
single occurence of abs gpio-buttons.
Changes since v1:
* Corrected cc list - now the mailing lists are looped in.
.../devicetree/bindings/input/gpio-keys.txt | 50 +++++++++++++++++++++-
drivers/input/keyboard/gpio_keys.c | 29 +++++++++++--
2 files changed, 75 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/gpio-keys.txt b/Documentation/devicetree/bindings/input/gpio-keys.txt
index a949404..1b53eed 100644
--- a/Documentation/devicetree/bindings/input/gpio-keys.txt
+++ b/Documentation/devicetree/bindings/input/gpio-keys.txt
@@ -22,6 +22,13 @@ both at the same time. Specifying both properties is allowed.
Optional subnode-properties:
- linux,input-type: Specify event type this button/key generates.
If not specified defaults to <1> == EV_KEY.
+ - linux,input-value: If linux,input-type is EV_ABS or EV_REL then this
+ value is sent for events this button generates when pressed.
+ EV_ABS/EV_REL axis will generate an event with a value of 0 when
+ all buttons with linux,input-type == type and linux,code == axis
+ are released. This value is interpreted as a signed 32 bit value,
+ e.g. to make a button generate a value of -1 use:
+ linux,input-value = <0xffffffff>; /* -1 */
- debounce-interval: Debouncing interval time in milliseconds.
If not specified defaults to 5.
- wakeup-source: Boolean, button can wake-up the system.
@@ -47,4 +54,45 @@ Example nodes:
linux,code = <108>;
interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
};
- ...
+ ...
+
+ gpio-joystick: {
+ compatible = "gpio-keys";
+
+ pinctrl-names = "default";
+ pinctrl-0 = <&my_pins>;
+
+ up {
+ gpios = <&gpio 26 1>;
+ linux,input-type = <EV_ABS>;
+ linux,code = <ABS_Y>;
+ linux,input-value = <0xffffffff>;
+ };
+
+ down {
+ gpios = <&gpio 13 1>;
+ linux,input-type = <EV_ABS>;
+ linux,code = <ABS_Y>;
+ linux,input-value = <1>;
+ };
+
+ left {
+ gpios = <&gpio 6 1>;
+ linux,input-type = <EV_ABS>;
+ linux,code = <ABS_X>;
+ linux,input-value = <0xffffffff>;
+ };
+
+ right {
+ gpios = <&gpio 5 1>;
+ linux,input-type = <EV_ABS>;
+ linux,code = <ABS_X>;
+ linux,input-value = <0x1>;
+ };
+
+ trigger_button {
+ gpios = <&gpio 12 1>;
+ linux,code = <BTN_TRIGGER>;
+ };
+ };
+ ...
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 9c92cdf..06d6902 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -370,9 +370,11 @@ static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
return;
}
- if (type == EV_ABS) {
+ if (type == EV_ABS || type == EV_REL) {
if (state)
input_event(input, type, button->code, button->value);
+ else
+ input_event(input, type, button->code, 0);
} else {
input_event(input, type, *bdata->code, state);
}
@@ -584,6 +586,14 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
*bdata->code = button->code;
input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
+ if (button->type == EV_ABS) {
+ if (input_abs_get_max(input, button->code) < button->value)
+ input_abs_set_max(input, button->code, button->value);
+
+ if (input_abs_get_min(input, button->code) > button->value)
+ input_abs_set_min(input, button->code, button->value);
+ }
+
/*
* Install custom action to cancel release timer and
* workqueue item.
@@ -667,6 +677,7 @@ static void gpio_keys_close(struct input_dev *input)
struct gpio_keys_button *button;
struct fwnode_handle *child;
int nbuttons;
+ int error;
nbuttons = device_get_child_node_count(dev);
if (nbuttons == 0)
@@ -701,9 +712,21 @@ static void gpio_keys_close(struct input_dev *input)
fwnode_property_read_string(child, "label", &button->desc);
- if (fwnode_property_read_u32(child, "linux,input-type",
- &button->type))
+ error = fwnode_property_read_u32(child, "linux,input-type",
+ &button->type);
+ if (error) {
button->type = EV_KEY;
+ } else {
+ error = fwnode_property_read_u32(child,
+ "linux,input-value",
+ &button->value);
+ if ((button->type == EV_ABS || button->type == EV_REL)
+ && error) {
+ dev_err(dev,
+ "EV_ABS/EV_REL button without value\n");
+ return ERR_PTR(-EINVAL);
+ }
+ }
button->wakeup =
fwnode_property_read_bool(child, "wakeup-source") ||
--
1.9.1
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