[PATCH 2/2] Input: gpio-keys: add device tree probe support
Shawn Guo
shawn.guo at linaro.org
Mon Jul 18 12:45:08 EDT 2011
It adds device tree probe support for gpio-keys driver.
One thing to note is that .enable/.disable hooks becomes unsupported
when the driver gets probed from device tree. The reason why the
patch does not address that is primarily because there are only 2
out of over 120 boards using the hooks for the gpio-keys device.
board-4430sdp pulls up/down a gpio, while board-mop500 enables/disables
a regulator in that pair of hooks. There is no common pattern at all,
so the patch leaves the hooks outside the device tree support.
Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Phil Blundell <pb at handhelds.org>
Cc: Dmitry Torokhov <dtor at mail.ru>
---
Documentation/devicetree/bindings/gpio/key.txt | 57 ++++++++++++++++
drivers/input/keyboard/gpio_keys.c | 83 +++++++++++++++++++++++-
2 files changed, 139 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/key.txt
diff --git a/Documentation/devicetree/bindings/gpio/key.txt b/Documentation/devicetree/bindings/gpio/key.txt
new file mode 100644
index 0000000..36296c1b
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/key.txt
@@ -0,0 +1,57 @@
+* Keys connected to GPIO lines
+
+Required properties:
+- compatible : Should be "gpio-keys"
+
+Optional properties:
+- keys-auto-repeat : Indicates the support of Auto-Repeat
+
+Each key is represented as a sub-node of the gpio-keys device. Each
+node's name represents the name of the corresponding key.
+
+Key sub-node properties:
+
+Required properties:
+- gpios : Should specify the key's GPIO. Active low key should be
+ indicated using flags in the GPIO specifier.
+- linux,key-code : Should specify the key code defined by linux in
+ include/linux/input.h
+
+Optional properties:
+- label : Contains the label for this key
+- key-debounce-internal : Specifies debounce interval in milliseconds
+- key-axis-value : Specifies axis value for an absolute change event
+- key-is-switch : Indicates the key is used as a switch event
+- key-is-active-low : Indicates the key is active low
+- key-can-wakeup-system : Indicates the key is a wake-up source
+- key-can-be-disabled : Indicates the key can be disabled
+
+Examples:
+
+gpio-keys {
+ compatible = "gpio-keys";
+
+ power {
+ label = "Power Button";
+ gpios = <&gpio0 8 0>;
+ linux,key-code = <116>; /* KEY_POWER */
+ key-is-active-low;
+ key-can-wakeup-system;
+ };
+
+ volume-up {
+ label = "Volume Up";
+ gpios = <&gpio1 14 0>;
+ linux,key-code = <115>; /* KEY_VOLUMEUP */
+ key-is-active-low;
+ key-can-wakeup-system;
+ };
+
+ volume-down {
+ label = "Volume Down";
+ gpios = <&gpio1 15 0>;
+ linux,key-code = <114>; /* KEY_VOLUMEDOWN */
+ key-is-active-low;
+ key-can-wakeup-system;
+ };
+};
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 85b5685..2a79d40 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -25,6 +25,8 @@
#include <linux/gpio_keys.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
struct gpio_button_data {
struct gpio_keys_button button;
@@ -445,15 +447,93 @@ static void gpio_keys_close(struct input_dev *input)
ddata->disable(input->dev.parent);
}
+#ifdef CONFIG_OF_GPIO
+static const struct of_device_id gpio_keys_dt_ids[] = {
+ { .compatible = "gpio-keys", },
+ { /* sentinel */ }
+};
+
+static struct gpio_keys_platform_data * __devinit gpio_keys_probe_pdata_dt(
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node, *child;
+ struct gpio_keys_platform_data *pdata;
+ struct gpio_keys_button *button;
+ int count = 0;
+
+ if (!np)
+ return ERR_PTR(-ENODEV);
+
+ /* count keys in this device, so we know how much to allocate */
+ for_each_child_of_node(np, child)
+ count++;
+ if (!count)
+ return ERR_PTR(-ENODEV);
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata) +
+ sizeof(*button) * count, GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ pdata->buttons = (struct gpio_keys_button *) (pdata + 1);
+ pdata->nbuttons = count;
+
+ if (of_get_property(np, "keys-auto-repeat", NULL))
+ pdata->rep = 1;
+
+ button = pdata->buttons;
+ for_each_child_of_node(np, child) {
+ enum of_gpio_flags flags;
+
+ button->gpio = of_get_gpio_flags(child, 0, &flags);
+ of_property_read_string(child, "label", &button->desc);
+ of_property_read_u32(child, "linux,key-code", &button->code);
+ of_property_read_u32(child, "key-debounce-internal",
+ &button->debounce_interval);
+ if (!of_property_read_u32(child, "key-axis-value",
+ &button->value))
+ button->type = EV_ABS;
+ if (of_get_property(np, "key-is-switch", NULL))
+ button->type = EV_SW;
+ if (of_get_property(np, "key-is-active-low", NULL))
+ button->active_low = 1;
+ if (of_get_property(np, "key-can-wakeup-system", NULL))
+ button->wakeup = 1;
+ if (of_get_property(np, "key-can-be-disabled", NULL))
+ button->can_disable = 1;
+
+ button++;
+ }
+
+ return pdata;
+}
+#else /* CONFIG_OF_GPIO */
+#define of_gpio_keys_match NULL
+static inline struct gpio_keys_platform_data *gpio_keys_probe_pdata_dt(
+ struct platform_device *pdev)
+{
+ return ERR_PTR(-ENODEV);
+}
+#endif /* CONFIG_OF_GPIO */
+
static int __devinit gpio_keys_probe(struct platform_device *pdev)
{
- struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_keys_platform_data *pdata;
struct gpio_keys_drvdata *ddata;
struct device *dev = &pdev->dev;
struct input_dev *input;
int i, error;
int wakeup = 0;
+ pdata = gpio_keys_probe_pdata_dt(pdev);
+ if (IS_ERR(pdata))
+ pdata = pdev->dev.platform_data;
+
+ if (IS_ERR_OR_NULL(pdata)) {
+ dev_err(dev, "failed to get platform data\n");
+ return PTR_ERR(pdata);
+ }
+
ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
pdata->nbuttons * sizeof(struct gpio_button_data),
GFP_KERNEL);
@@ -631,6 +711,7 @@ static struct platform_driver gpio_keys_device_driver = {
#ifdef CONFIG_PM
.pm = &gpio_keys_pm_ops,
#endif
+ .of_match_table = gpio_keys_dt_ids,
}
};
--
1.7.4.1
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