Input: gpio-keys debouncing support

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index bbd00c3fe98ca18999b19c011a8c0040f3e9fb9b..be58730e636a4323c1aca62d136e94ec40700bcf 100644 (file)
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -26,23 +26,54 @@
 
 #include <asm/gpio.h>
 
+struct gpio_button_data {
+       struct gpio_keys_button *button;
+       struct input_dev *input;
+       struct timer_list timer;
+};
+
+struct gpio_keys_drvdata {
+       struct input_dev *input;
+       struct gpio_button_data data[0];
+};
+
+static void gpio_keys_report_event(struct gpio_keys_button *button,
+                                  struct input_dev *input)
+{
+       unsigned int type = button->type ?: EV_KEY;
+       int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
+
+       input_event(input, type, button->code, !!state);
+       input_sync(input);
+}
+
+static void gpio_check_button(unsigned long _data)
+{
+       struct gpio_button_data *data = (struct gpio_button_data *)_data;
+
+       gpio_keys_report_event(data->button, data->input);
+}
+
 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
 {
-       int i;
        struct platform_device *pdev = dev_id;
        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
-       struct input_dev *input = platform_get_drvdata(pdev);
+       struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
+       int i;
 
        for (i = 0; i < pdata->nbuttons; i++) {
                struct gpio_keys_button *button = &pdata->buttons[i];
-               int gpio = button->gpio;
 
-               if (irq == gpio_to_irq(gpio)) {
-                       unsigned int type = button->type ?: EV_KEY;
-                       int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
+               if (irq == gpio_to_irq(button->gpio)) {
+                       struct gpio_button_data *bdata = &ddata->data[i];
+
+                       if (button->debounce_interval)
+                               mod_timer(&bdata->timer,
+                                         jiffies +
+                                         msecs_to_jiffies(button->debounce_interval));
+                       else
+                               gpio_keys_report_event(button, bdata->input);
 
-                       input_event(input, type, button->code, !!state);
-                       input_sync(input);
                        return IRQ_HANDLED;
                }
        }
@@ -53,17 +84,21 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
 static int __devinit gpio_keys_probe(struct platform_device *pdev)
 {
        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+       struct gpio_keys_drvdata *ddata;
        struct input_dev *input;
        int i, error;
        int wakeup = 0;
 
+       ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
+                       pdata->nbuttons * sizeof(struct gpio_button_data),
+                       GFP_KERNEL);
        input = input_allocate_device();
-       if (!input)
-               return -ENOMEM;
-
-       platform_set_drvdata(pdev, input);
+       if (!ddata || !input) {
+               error = -ENOMEM;
+               goto fail1;
+       }
 
-       input->evbit[0] = BIT_MASK(EV_KEY);
+       platform_set_drvdata(pdev, ddata);
 
        input->name = pdev->name;
        input->phys = "gpio-keys/input0";
@@ -74,16 +109,23 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
        input->id.product = 0x0001;
        input->id.version = 0x0100;
 
+       ddata->input = input;
+
        for (i = 0; i < pdata->nbuttons; i++) {
                struct gpio_keys_button *button = &pdata->buttons[i];
+               struct gpio_button_data *bdata = &ddata->data[i];
                int irq;
                unsigned int type = button->type ?: EV_KEY;
 
+               bdata->input = input;
+               setup_timer(&bdata->timer,
+                           gpio_check_button, (unsigned long)bdata);
+
                error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
                if (error < 0) {
                        pr_err("gpio-keys: failed to request GPIO %d,"
                                " error %d\n", button->gpio, error);
-                       goto fail;
+                       goto fail2;
                }
 
                error = gpio_direction_input(button->gpio);
@@ -92,7 +134,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
                                " direction for GPIO %d, error %d\n",
                                button->gpio, error);
                        gpio_free(button->gpio);
-                       goto fail;
+                       goto fail2;
                }
 
                irq = gpio_to_irq(button->gpio);
@@ -102,7 +144,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
                                " for GPIO %d, error %d\n",
                                button->gpio, error);
                        gpio_free(button->gpio);
-                       goto fail;
+                       goto fail2;
                }
 
                error = request_irq(irq, gpio_keys_isr,
@@ -114,7 +156,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
                        pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
                                irq, error);
                        gpio_free(button->gpio);
-                       goto fail;
+                       goto fail2;
                }
 
                if (button->wakeup)
@@ -127,21 +169,25 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
        if (error) {
                pr_err("gpio-keys: Unable to register input device, "
                        "error: %d\n", error);
-               goto fail;
+               goto fail2;
        }
 
        device_init_wakeup(&pdev->dev, wakeup);
 
        return 0;
 
- fail:
+ fail2:
        while (--i >= 0) {
                free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
+               if (pdata->buttons[i].debounce_interval)
+                       del_timer_sync(&ddata->data[i].timer);
                gpio_free(pdata->buttons[i].gpio);
        }
 
        platform_set_drvdata(pdev, NULL);
+ fail1:
        input_free_device(input);
+       kfree(ddata);
 
        return error;
 }
@@ -149,7 +195,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 {
        struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
-       struct input_dev *input = platform_get_drvdata(pdev);
+       struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
+       struct input_dev *input = ddata->input;
        int i;
 
        device_init_wakeup(&pdev->dev, 0);
@@ -157,6 +204,8 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
        for (i = 0; i < pdata->nbuttons; i++) {
                int irq = gpio_to_irq(pdata->buttons[i].gpio);
                free_irq(irq, pdev);
+               if (pdata->buttons[i].debounce_interval)
+                       del_timer_sync(&ddata->data[i].timer);
                gpio_free(pdata->buttons[i].gpio);
        }
 

diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h
index c6d3a9de5634c1d9de24c962b4fada1aaa97b4a2..ec6ecd74781dca68bdf49c3ea1b80cc00b9d4966 100644 (file)
--- a/include/linux/gpio_keys.h
+++ b/include/linux/gpio_keys.h
@@ -9,6 +9,7 @@ struct gpio_keys_button {
        char *desc;
        int type;               /* input event type (EV_KEY, EV_SW) */
        int wakeup;             /* configure the button as a wake-up source */
+       int debounce_interval;  /* debounce ticks interval in msecs */
 };
 
 struct gpio_keys_platform_data {