This patch add debouncing support for the generic gpio input device, since debouncing is most likely to happen.
Comments welcome.
Signed-off-by: Keith Mok <ek9852@xxxxxxxxx>
---
Keith Mok
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 6a9ca4b..79b460e 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -26,26 +26,36 @@
#include <asm/gpio.h>
+static void do_gpio_keys_tasklet(unsigned long);
+static void do_gpio_keys_timer(unsigned long);
+
+static struct timer_list gpio_keys_timer;
+DECLARE_TASKLET_DISABLED(gpio_keys_tasklet, do_gpio_keys_tasklet, 0);
+static spinlock_t suspend_lock;
+static int suspended;
+
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);
-
- for (i = 0; i < pdata->nbuttons; i++) {
- struct gpio_keys_button *button = &pdata->buttons[i];
- int gpio = button->gpio;
+ int i;
+ unsigned long flags;
- if (irq == gpio_to_irq(gpio)) {
- unsigned int type = button->type ?: EV_KEY;
- int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
+ spin_lock_irqsave(&suspend_lock, flags);
+ if (suspended) {
+ spin_unlock_irqrestore(&suspend_lock, flags);
+ return IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&suspend_lock, flags);
- input_event(input, type, button->code, !!state);
- input_sync(input);
- }
+ /* disable keyboard interrupt and schedule for handling */
+ for (i = 0; i < pdata->nbuttons; i++) {
+ int irq = gpio_to_irq(pdata->buttons[i].gpio);
+ disable_irq(irq);
}
+ tasklet_schedule(&gpio_keys_tasklet);
+
return IRQ_HANDLED;
}
@@ -63,6 +73,11 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, input);
input->evbit[0] = BIT_MASK(EV_KEY);
+ setup_timer(&gpio_keys_timer, do_gpio_keys_timer, (unsigned long) pdev);
+ tasklet_enable(&gpio_keys_tasklet);
+ gpio_keys_tasklet.data = (unsigned long) pdev;
+ spin_lock_init(&suspend_lock);
+ suspended = 0;
input->name = pdev->name;
input->phys = "gpio-keys/input0";
@@ -156,9 +171,14 @@ 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);
- gpio_free(pdata->buttons[i].gpio);
}
+ del_timer_sync(&gpio_keys_timer);
+ tasklet_kill(&gpio_keys_tasklet);
+
+ for (i = 0; i < pdata->nbuttons; i++)
+ gpio_free(pdata->buttons[i].gpio);
+
input_unregister_device(input);
return 0;
@@ -168,9 +188,29 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
#ifdef CONFIG_PM
static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
{
+ unsigned long flags;
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
int i;
+ spin_lock_irqsave(&suspend_lock, flags);
+
+ /*
+ * Re-enable the interrupt in case it has been masked by the
+ * handler and a key is still pressed. We need the interrupt
+ * to wake us up from suspended.
+ */
+
+ suspended = 1;
+
+ spin_unlock_irqrestore(&suspend_lock, flags);
+ del_timer_sync(&gpio_keys_timer);
+ tasklet_kill(&gpio_keys_tasklet);
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ int irq = gpio_to_irq(pdata->buttons[i].gpio);
+ enable_irq(irq);
+ }
+
if (device_may_wakeup(&pdev->dev)) {
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
@@ -189,6 +229,7 @@ static int gpio_keys_resume(struct platform_device *pdev)
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
int i;
+ suspended = 0;
if (device_may_wakeup(&pdev->dev)) {
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
@@ -206,6 +247,45 @@ static int gpio_keys_resume(struct platform_device *pdev)
#define gpio_keys_resume NULL
#endif
+static void do_gpio_keys_tasklet(unsigned long data)
+{
+ int pressed;
+ int i;
+ struct platform_device *pdev = (struct platform_device*)data;
+ struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
+ struct input_dev *input = platform_get_drvdata(pdev);
+
+ /* check for any changes */
+ pressed = 0;
+ for (i = 0; i < pdata->nbuttons; i++) {
+ struct gpio_keys_button *button = &pdata->buttons[i];
+ int gpio = button->gpio;
+
+ unsigned int type = button->type ?: EV_KEY;
+ int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
+
+ input_event(input, type, button->code, !!state);
+ pressed |= !!state;
+ input_sync(input);
+ }
+ if(pressed) {
+ int delay = HZ / 20;
+ /* some key is pressed - keep irq disabled and use timer
+ * to poll */
+ mod_timer(&gpio_keys_timer, jiffies + delay);
+ } else {
+ for (i = 0; i < pdata->nbuttons; i++) {
+ int irq = gpio_to_irq(pdata->buttons[i].gpio);
+ enable_irq(irq);
+ }
+ }
+}
+
+static void do_gpio_keys_timer(unsigned long data)
+{
+ tasklet_schedule(&gpio_keys_tasklet);
+}
+
struct platform_driver gpio_keys_device_driver = {
.probe = gpio_keys_probe,
.remove = __devexit_p(gpio_keys_remove),
-
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