From: Alexander Clouter <a...@digriz.org.uk> This implements an optional polling mode for the gpio_keys driver, necessary for GPIOs that are not able to generate IRQs.
gpio_keys_platform_data has been extended with poll_interval which specifies the polling interval in ms, this is passed onto input-polldev. This work is a rebase of the patch by Alex Clouter [1] which was based on the patch [2] originally conceived by Paul Mundt. Signed-off-by: Paul Mundt <let...@linux-sh.org> Signed-off-by: Alexander Clouter <a...@digriz.org.uk> Signed-off-by: Ben Gardiner <bengardi...@nanometrics.ca> Reviewed-by: Chris Cordahi <christophercord...@nanometrics.ca> CC: Paul Mundt <let...@linux-sh.org> [1] http://article.gmane.org/gmane.linux.kernel.input/13919 [2] http://article.gmane.org/gmane.linux.kernel.input/5814 --- Changes since v3: * no changes to this patch in the series Changes since v2: * rebased to 083eae3e28643e0eefc5243719f8b1572cf98299 of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci.git Changes since v1: * use locally defined functions that are no-ops/error checkers when INPUT_POLLDEV is not defined. * disable polling mode support when input-polldev is a module and gpio_keys is builtin Changes since [1]: * rebased to 0b1c3ef1072f2b97c86351d3736d2b2d00293a11 of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci.git * use _cansleep variant of gpio_get_value in the polling task to avoid WARN_ON when using I2C GPIO expanders * prevent unitialized access to 'input' in gpio_keys_close() Changes since [2]: * absolute dependency on INPUT_POLLDEV removed Tested with CONFIG_INPUT_POLLDEV={n,m,y} (gpio_keys as module for 'm'). --- drivers/input/keyboard/gpio_keys.c | 120 ++++++++++++++++++++++++++++++------ include/linux/gpio_keys.h | 1 + 2 files changed, 103 insertions(+), 18 deletions(-) diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c index 6069abe..d2f23d9 100644 --- a/drivers/input/keyboard/gpio_keys.c +++ b/drivers/input/keyboard/gpio_keys.c @@ -1,7 +1,9 @@ /* - * Driver for keys on GPIO lines capable of generating interrupts. + * Driver for keys on GPIO lines, either IRQ-driven or polled. * * Copyright 2005 Phil Blundell + * Copyright 2008 Paul Mundt + * Copyright 2010 Alexander Clouter <a...@digriz.org.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -25,6 +27,7 @@ #include <linux/gpio_keys.h> #include <linux/workqueue.h> #include <linux/gpio.h> +#include <linux/input-polldev.h> struct gpio_button_data { struct gpio_keys_button *button; @@ -37,6 +40,7 @@ struct gpio_button_data { struct gpio_keys_drvdata { struct input_dev *input; + struct input_polled_dev *poll_dev; struct mutex disable_lock; unsigned int n_buttons; int (*enable)(struct device *dev); @@ -44,6 +48,30 @@ struct gpio_keys_drvdata { struct gpio_button_data data[0]; }; +#if (!defined(CONFIG_INPUT_POLLDEV) && !defined(CONFIG_INPUT_POLLDEV_MODULE)) \ + || (defined(CONFIG_INPUT_POLLDEV_MODULE) \ + && !defined(CONFIG_KEYBOARD_GPIO_MODULE)) + +static inline struct input_polled_dev *allocate_polled_device( + const struct device *dev) +{ + dev_err(dev, "device needs polling (enable INPUT_POLLDEV)\n"); + return NULL; +} + +#define free_polled_device(x) do { } while (0) +#define register_polled_device(x) (-ENXIO) +#define unregister_polled_device(x) do { } while (0) + +#else + +#define allocate_polled_device(x) input_allocate_polled_device() +#define free_polled_device(x) input_free_polled_device(x) +#define register_polled_device(x) input_register_polled_device(x) +#define unregister_polled_device(x) input_unregister_polled_device(x) + +#endif + /* * SYSFS interface for enabling/disabling keys and switches: * @@ -322,7 +350,8 @@ static void gpio_keys_report_event(struct gpio_button_data *bdata) struct gpio_keys_button *button = bdata->button; struct input_dev *input = bdata->input; unsigned int type = button->type ?: EV_KEY; - int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low; + int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) + ^ button->active_low; input_event(input, type, button->code, !!state); input_sync(input); @@ -343,6 +372,16 @@ static void gpio_keys_timer(unsigned long _data) schedule_work(&data->work); } +static void gpio_handle_button_event(struct gpio_keys_button *button, + struct gpio_button_data *bdata) +{ + if (bdata->timer_debounce) + mod_timer(&bdata->timer, + jiffies + msecs_to_jiffies(bdata->timer_debounce)); + else + gpio_keys_report_event(bdata); +} + static irqreturn_t gpio_keys_isr(int irq, void *dev_id) { struct gpio_button_data *bdata = dev_id; @@ -350,15 +389,24 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id) BUG_ON(irq != gpio_to_irq(button->gpio)); - if (bdata->timer_debounce) - mod_timer(&bdata->timer, - jiffies + msecs_to_jiffies(bdata->timer_debounce)); - else - schedule_work(&bdata->work); + gpio_handle_button_event(button, bdata); return IRQ_HANDLED; } +static void gpio_keys_poll(struct input_polled_dev *dev) +{ + struct gpio_keys_drvdata *ddata = dev->private; + int i; + + for (i = 0; i < ddata->n_buttons; i++) { + struct gpio_button_data *bdata = &ddata->data[i]; + struct gpio_keys_button *button = bdata->button; + + gpio_handle_button_event(button, bdata); + } +} + static int __devinit gpio_keys_setup_key(struct platform_device *pdev, struct gpio_button_data *bdata, struct gpio_keys_button *button) @@ -446,20 +494,28 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) struct gpio_keys_drvdata *ddata; struct device *dev = &pdev->dev; struct input_dev *input; + struct input_polled_dev *poll_dev; 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 (pdata->poll_interval) { + poll_dev = allocate_polled_device(dev); + input = poll_dev ? poll_dev->input : 0; + } else + input = input_allocate_device(); if (!ddata || !input) { dev_err(dev, "failed to allocate state\n"); error = -ENOMEM; goto fail1; } - ddata->input = input; + if (pdata->poll_interval) + ddata->poll_dev = poll_dev; + else + ddata->input = input; ddata->n_buttons = pdata->nbuttons; ddata->enable = pdata->enable; ddata->disable = pdata->disable; @@ -468,6 +524,12 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ddata); input_set_drvdata(input, ddata); + if (pdata->poll_interval) { + poll_dev->private = ddata; + poll_dev->poll = gpio_keys_poll; + poll_dev->poll_interval = pdata->poll_interval; + } + input->name = pdev->name; input->phys = "gpio-keys/input0"; input->dev.parent = &pdev->dev; @@ -491,14 +553,17 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) bdata->input = input; bdata->button = button; + input_set_capability(input, type, button->code); + + if (pdata->poll_interval) + continue; + error = gpio_keys_setup_key(pdev, bdata, button); if (error) goto fail2; if (button->wakeup) wakeup = 1; - - input_set_capability(input, type, button->code); } error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group); @@ -508,7 +573,10 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) goto fail2; } - error = input_register_device(input); + if (pdata->poll_interval) + error = register_polled_device(poll_dev); + else + error = input_register_device(input); if (error) { dev_err(dev, "Unable to register input device, error: %d\n", error); @@ -528,7 +596,9 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group); fail2: while (--i >= 0) { - free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]); + if (!pdata->poll_interval) + free_irq(gpio_to_irq(pdata->buttons[i].gpio), + &ddata->data[i]); if (ddata->data[i].timer_debounce) del_timer_sync(&ddata->data[i].timer); cancel_work_sync(&ddata->data[i].work); @@ -537,7 +607,10 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev) platform_set_drvdata(pdev, NULL); fail1: - input_free_device(input); + if (pdata->poll_interval) + free_polled_device(poll_dev); + else + input_free_device(input); kfree(ddata); return error; @@ -547,7 +620,8 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev) { struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); - struct input_dev *input = ddata->input; + struct input_dev *input; + struct input_polled_dev *poll_dev; int i; sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group); @@ -555,15 +629,25 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 0); for (i = 0; i < pdata->nbuttons; i++) { - int irq = gpio_to_irq(pdata->buttons[i].gpio); - free_irq(irq, &ddata->data[i]); + if (!pdata->poll_interval) { + int irq = gpio_to_irq(pdata->buttons[i].gpio); + free_irq(irq, &ddata->data[i]); + } if (ddata->data[i].timer_debounce) del_timer_sync(&ddata->data[i].timer); cancel_work_sync(&ddata->data[i].work); gpio_free(pdata->buttons[i].gpio); } - input_unregister_device(input); + if (pdata->poll_interval) { + poll_dev = ddata->poll_dev; + unregister_polled_device(poll_dev); + free_polled_device(poll_dev); + } else { + input = ddata->input; + input_unregister_device(input); + input_free_device(input); + } return 0; } diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h index ce73a30..5fdd495 100644 --- a/include/linux/gpio_keys.h +++ b/include/linux/gpio_keys.h @@ -19,6 +19,7 @@ struct gpio_keys_platform_data { unsigned int rep:1; /* enable input subsystem auto repeat */ int (*enable)(struct device *dev); void (*disable)(struct device *dev); + unsigned int poll_interval; /* polling interval in ms */ }; #endif -- 1.7.0.4 _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
