From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Mok Subject: [PATCH] input: add debouncing for generic gpio input device gpio_key.c Date: Sun, 24 Feb 2008 14:07:03 +0800 Message-ID: <47C10987.9020804@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rv-out-0910.google.com ([209.85.198.188]:52343 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755433AbYBXGFg (ORCPT ); Sun, 24 Feb 2008 01:05:36 -0500 Received: by rv-out-0910.google.com with SMTP id k20so664634rvb.1 for ; Sat, 23 Feb 2008 22:05:35 -0800 (PST) Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: dmitry.torokhov@gmail.com, dtor@mail.ru Cc: linux-input@vger.kernel.org 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 --- 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 +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),