Input: gpio-keys debouncing support

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

1 files changed, 69 insertions, 20 deletions

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index bbd00c3fe98c..be58730e636a 100644
--- 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);
         }