Hi,
What about this patch? I still got no comments.
On Thu, Mar 20, 2008 at 01:13:23AM +0300, Dmitry Baryshkov wrote:
> Sometimes the gpio line can generates jitter while transitioning
> from one state to another. Implement a way to filter such noise during
> transitions.
>
> Signed-off-by: Dmitry Baryshkov <dbaryshkov@xxxxxxxxx>
> ---
> drivers/input/keyboard/Kconfig | 7 +++
> drivers/input/keyboard/gpio_keys.c | 96 ++++++++++++++++++++++++++++++++++--
> include/linux/gpio_keys.h | 6 ++
> 3 files changed, 104 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 8ea709b..0fb4592 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -295,6 +295,13 @@ config KEYBOARD_GPIO
> To compile this driver as a module, choose M here: the
> module will be called gpio-keys.
>
> +config KEYBOARD_GPIO_DEBOUNCE
> + bool "GPIO Buttons debouncer"
> + depends on KEYBOARD_GPIO
> + help
> + This driver will enable the debouncer in the gpio-keys
> + driver for pins that take some time to come to stable state.
> +
> config KEYBOARD_MAPLE
> tristate "Maple bus keyboard"
> depends on SH_DREAMCAST && MAPLE
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index 6a9ca4b..577dfea 100644
> --- a/drivers/input/keyboard/gpio_keys.c
> +++ b/drivers/input/keyboard/gpio_keys.c
> @@ -26,6 +26,39 @@
>
> #include <asm/gpio.h>
>
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> +struct gpio_debounce_data {
> + struct platform_device *pdev;
> + struct gpio_keys_button *button;
> + int state;
> + int count;
> +};
> +
> +static void gpio_debounce_timer(unsigned long _data)
> +{
> + struct gpio_debounce_data *data = (struct gpio_debounce_data *)_data;
> + struct gpio_keys_button *button = data->button;
> + int gpio = button->gpio;
> + unsigned int type = button->type ?: EV_KEY;
> + int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
> + struct input_dev *input = platform_get_drvdata(data->pdev);
> +
> + if (state != data->state) {
> + data->count = 0;
> + data->state = state;
> + mod_timer(&button->timer, jiffies +
> + msecs_to_jiffies(button->interval));
> + } else if (data->count < button->count) {
> + data->count ++;
> + mod_timer(&button->timer, jiffies +
> + msecs_to_jiffies(button->interval));
> + } else {
> + input_event(input, type, button->code, !!state);
> + input_sync(input);
> + }
> +}
> +#endif
> +
> static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
> {
> int i;
> @@ -38,11 +71,21 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
> 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;
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + if (button->count) {
> + if (!timer_pending(&button->timer))
> + mod_timer(&button->timer, jiffies +
> + msecs_to_jiffies(
> + button->interval));
> + } else
> +#endif
> + {
> + 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);
> - input_sync(input);
> + input_event(input, type, button->code, !!state);
> + input_sync(input);
> + }
> }
> }
>
> @@ -103,6 +146,31 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
> gpio_free(button->gpio);
> goto fail;
> }
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + if (button->count && button->interval) {
> + struct gpio_debounce_data *data;
> + data = kzalloc(sizeof(struct gpio_debounce_data), GFP_KERNEL);
> + if (!data) {
> + error = -ENOMEM;
> + pr_err("gpio-keys: Unable to allocate debounce data"
> + " for GPIO %d, error %d\n",
> + button->gpio, error);
> + gpio_free(button->gpio);
> + goto fail;
> + }
> +
> + data->pdev = pdev;
> + data->button = button;
> + data->state = -1;
> +
> + init_timer(&button->timer);
> + button->timer.function = gpio_debounce_timer;
> + button->timer.data = (unsigned long)data;
> +
> + mod_timer(&button->timer, jiffies +
> + msecs_to_jiffies(button->interval));
> + }
> +#endif
>
> error = request_irq(irq, gpio_keys_isr,
> IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
> @@ -112,6 +180,12 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
> if (error) {
> pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
> irq, error);
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + if (button->count) {
> + del_timer_sync(&button->timer);
> + kfree((void*)button->timer.data);
> + }
> +#endif
> gpio_free(button->gpio);
> goto fail;
> }
> @@ -136,6 +210,12 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
> fail:
> while (--i >= 0) {
> free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + if (pdata->buttons[i].count) {
> + del_timer_sync(&pdata->buttons[i].timer);
> + kfree((void*)pdata->buttons[i].timer.data);
> + }
> +#endif
> gpio_free(pdata->buttons[i].gpio);
> }
>
> @@ -156,6 +236,12 @@ 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);
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + if (pdata->buttons[i].count) {
> + del_timer_sync(&pdata->buttons[i].timer);
> + kfree((void*)pdata->buttons[i].timer.data);
> + }
> +#endif
> gpio_free(pdata->buttons[i].gpio);
> }
>
> diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h
> index c6d3a9d..2432e62 100644
> --- a/include/linux/gpio_keys.h
> +++ b/include/linux/gpio_keys.h
> @@ -9,6 +9,12 @@ 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 */
> +#ifdef CONFIG_KEYBOARD_GPIO_DEBOUNCE
> + int count;
> + int interval; /* in msecs */
> + /* private: */
> + struct timer_list timer;
> +#endif
> };
>
> struct gpio_keys_platform_data {
> --
> 1.5.4.3
>
>
> --
> With best wishes
> Dmitry
>
--
With best wishes
Dmitry
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