[PATCH v2] input: gpio_keys_polled: convert to dt

From: Alexandre Pereira da Silva
Date: Mon Jun 25 2012 - 16:44:16 EST


Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@xxxxxxxxx>
---
Applies to v3.5-rc4

Changes since v1:
* Add biding documentation
* Fix sizeof in memset
* Cleanup dt properties extraction
* Use for_each macro
* Fix memleak on buttons

Thanks Rob Herring, Dmitry Torokhov and Roland Stiege for reviewing and
improvements suggestions.

.../devicetree/bindings/input/gpio-keys-polled.txt | 38 ++++++
drivers/input/keyboard/gpio_keys_polled.c | 131 ++++++++++++++++++--
2 files changed, 158 insertions(+), 11 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/gpio-keys-polled.txt

diff --git a/Documentation/devicetree/bindings/input/gpio-keys-polled.txt b/Documentation/devicetree/bindings/input/gpio-keys-polled.txt
new file mode 100644
index 0000000..313abef
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/gpio-keys-polled.txt
@@ -0,0 +1,38 @@
+Device-Tree bindings for input/gpio_keys_polled.c keyboard driver
+
+Required properties:
+ - compatible = "gpio-keys-polled";
+ - poll-interval: Poll interval time in milliseconds
+
+Optional properties:
+ - autorepeat: Boolean, Enable auto repeat feature of Linux input
+ subsystem.
+
+Each button (key) is represented as a sub-node of "gpio-keys-polled":
+Subnode properties:
+
+ - gpios: OF device-tree gpio specification.
+ - label: Descriptive name of the key.
+ - linux,code: Keycode to emit.
+
+Optional subnode-properties:
+ - linux,input-type: Specify event type this button/key generates.
+ If not specified defaults to <1> == EV_KEY.
+ - debounce-interval: Debouncing interval time in milliseconds.
+ If not specified defaults to 5.
+ - gpio-key,wakeup: Boolean, button can wake-up the system.
+
+Example nodes:
+
+ gpio_keys_polled {
+ compatible = "gpio-keys-polled";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ poll-interval = <100>;
+ autorepeat;
+ button@21 {
+ label = "GPIO Key UP";
+ linux,code = <103>;
+ gpios = <&gpio1 0 1>;
+ };
+ ...
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index 20c8ab1..e5cb3ef 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -25,6 +25,8 @@
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/gpio_keys.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>

#define DRV_NAME "gpio-keys-polled"

@@ -38,7 +40,7 @@ struct gpio_keys_button_data {
struct gpio_keys_polled_dev {
struct input_polled_dev *poll_dev;
struct device *dev;
- struct gpio_keys_platform_data *pdata;
+ struct gpio_keys_platform_data pdata;
struct gpio_keys_button_data data[0];
};

@@ -67,11 +69,11 @@ static void gpio_keys_polled_check_state(struct input_dev *input,
static void gpio_keys_polled_poll(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
- struct gpio_keys_platform_data *pdata = bdev->pdata;
+ struct gpio_keys_platform_data *pdata = &bdev->pdata;
struct input_dev *input = dev->input;
int i;

- for (i = 0; i < bdev->pdata->nbuttons; i++) {
+ for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button_data *bdata = &bdev->data[i];

if (bdata->count < bdata->threshold)
@@ -85,7 +87,7 @@ static void gpio_keys_polled_poll(struct input_polled_dev *dev)
static void gpio_keys_polled_open(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
- struct gpio_keys_platform_data *pdata = bdev->pdata;
+ struct gpio_keys_platform_data *pdata = &bdev->pdata;

if (pdata->enable)
pdata->enable(bdev->dev);
@@ -94,31 +96,125 @@ static void gpio_keys_polled_open(struct input_polled_dev *dev)
static void gpio_keys_polled_close(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
- struct gpio_keys_platform_data *pdata = bdev->pdata;
+ struct gpio_keys_platform_data *pdata = &bdev->pdata;

if (pdata->disable)
pdata->disable(bdev->dev);
}
+#ifdef CONFIG_OF
+static int gpio_keys_polled_get_devtree_pdata(struct device *dev,
+ struct gpio_keys_platform_data *pdata)
+{
+ struct device_node *node, *pp;
+ int i;
+ struct gpio_keys_button *buttons;
+
+ node = dev->of_node;
+ if (node == NULL)
+ return -ENODEV;
+
+ memset(pdata, 0, sizeof(*pdata));
+
+ pdata->rep = !!of_get_property(node, "autorepeat", NULL);
+
+ of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
+
+ pdata->nbuttons = of_get_child_count(node);
+ if (pdata->nbuttons == 0)
+ return -ENODEV;
+
+ buttons = kzalloc(pdata->nbuttons * (sizeof *buttons), GFP_KERNEL);
+ if (!buttons)
+ return -ENOMEM;
+
+ i = 0;
+ for_each_child_of_node(node, pp) {
+ enum of_gpio_flags flags;
+
+ if (!of_find_property(pp, "gpios", NULL)) {
+ pdata->nbuttons--;
+ dev_warn(dev, "Found button without gpios\n");
+ continue;
+ }
+ buttons[i].gpio = of_get_gpio_flags(pp, 0, &flags);
+ buttons[i].active_low = flags & OF_GPIO_ACTIVE_LOW;
+
+ if (of_property_read_u32(pp, "linux,code", &buttons[i].code)) {
+ dev_err(dev, "Button without keycode: 0x%x\n",
+ buttons[i].gpio);
+ goto out_fail;
+ }
+
+ buttons[i].desc = of_get_property(pp, "label", NULL);
+
+ if (of_property_read_u32(pp, "linux,input-type",
+ &buttons[i].type))
+ buttons[i].type = EV_KEY;
+
+ buttons[i].wakeup = !!of_get_property(pp, "gpio-key,wakeup",
+ NULL);
+
+ if (of_property_read_u32(pp, "debounce-interval",
+ &buttons[i].debounce_interval))
+ buttons[i].debounce_interval = 5;
+
+ i++;
+ }
+
+ pdata->buttons = buttons;
+
+ return 0;
+
+out_fail:
+ kfree(buttons);
+ return -ENODEV;
+}
+
+static struct of_device_id gpio_keys_polled_of_match[] = {
+ { .compatible = "gpio-keys-polled", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
+
+#else
+
+static int gpio_keys_polled_get_devtree_pdata(struct device *dev,
+ struct gpio_keys_platform_data *altp)
+{
+ return -ENODEV;
+}
+#endif

static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
{
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
struct device *dev = &pdev->dev;
+ struct gpio_keys_platform_data alt_pdata;
struct gpio_keys_polled_dev *bdev;
struct input_polled_dev *poll_dev;
struct input_dev *input;
int error;
int i;

- if (!pdata || !pdata->poll_interval)
- return -EINVAL;
+ if (!pdata) {
+ error = gpio_keys_polled_get_devtree_pdata(dev, &alt_pdata);
+ if (error)
+ return error;
+ pdata = &alt_pdata;
+ }
+
+ if (!pdata->poll_interval) {
+ error = -EINVAL;
+ goto err_free_buttons;
+ }

bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
pdata->nbuttons * sizeof(struct gpio_keys_button_data),
GFP_KERNEL);
if (!bdev) {
dev_err(dev, "no memory for private data\n");
- return -ENOMEM;
+ error = -ENOMEM;
+ goto err_free_buttons;
}

poll_dev = input_allocate_polled_device();
@@ -184,7 +280,7 @@ static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)

bdev->poll_dev = poll_dev;
bdev->dev = dev;
- bdev->pdata = pdata;
+ bdev->pdata = *pdata;
platform_set_drvdata(pdev, bdev);

error = input_register_polled_device(poll_dev);
@@ -209,15 +305,19 @@ err_free_gpio:

err_free_bdev:
kfree(bdev);
-
platform_set_drvdata(pdev, NULL);
+
+err_free_buttons:
+ /* If we have no platform_data, we allocated buttons dynamically. */
+ if (!pdev->dev.platform_data)
+ kfree(pdata->buttons);
return error;
}

static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
{
struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
- struct gpio_keys_platform_data *pdata = bdev->pdata;
+ struct gpio_keys_platform_data *pdata = &bdev->pdata;
int i;

input_unregister_polled_device(bdev->poll_dev);
@@ -227,6 +327,14 @@ static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)

input_free_polled_device(bdev->poll_dev);

+ /*
+ * If we had no platform_data, we allocated buttons dynamically, and
+ * must free them here. pdata->buttons is the pointer to the
+ * beginning of the allocated array.
+ */
+ if (!pdev->dev.platform_data)
+ kfree(pdata->buttons);
+
kfree(bdev);
platform_set_drvdata(pdev, NULL);

@@ -239,6 +347,7 @@ static struct platform_driver gpio_keys_polled_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
},
};
module_platform_driver(gpio_keys_polled_driver);
--
1.7.10

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