diff options
Diffstat (limited to 'drivers/input/keyboard/gpio_keys_polled.c')
| -rw-r--r-- | drivers/input/keyboard/gpio_keys_polled.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c new file mode 100644 index 000000000000..4c17aff20657 --- /dev/null +++ b/drivers/input/keyboard/gpio_keys_polled.c @@ -0,0 +1,261 @@ +/* + * Driver for buttons on GPIO lines not capable of generating interrupts + * + * Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com> + * + * This file was based on: /drivers/input/misc/cobalt_btns.c + * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> + * + * also was based on: /drivers/input/keyboard/gpio_keys.c + * Copyright 2005 Phil Blundell + * + * 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 + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/input-polldev.h> +#include <linux/ioport.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/gpio_keys.h> + +#define DRV_NAME "gpio-keys-polled" + +struct gpio_keys_button_data { + int last_state; + int count; + int threshold; + int can_sleep; +}; + +struct gpio_keys_polled_dev { + struct input_polled_dev *poll_dev; + struct device *dev; + struct gpio_keys_platform_data *pdata; + struct gpio_keys_button_data data[0]; +}; + +static void gpio_keys_polled_check_state(struct input_dev *input, + struct gpio_keys_button *button, + struct gpio_keys_button_data *bdata) +{ + int state; + + if (bdata->can_sleep) + state = !!gpio_get_value_cansleep(button->gpio); + else + state = !!gpio_get_value(button->gpio); + + if (state != bdata->last_state) { + unsigned int type = button->type ?: EV_KEY; + + input_event(input, type, button->code, + !!(state ^ button->active_low)); + input_sync(input); + bdata->count = 0; + bdata->last_state = state; + } +} + +static void gpio_keys_polled_poll(struct input_polled_dev *dev) +{ + struct gpio_keys_polled_dev *bdev = dev->private; + struct gpio_keys_platform_data *pdata = bdev->pdata; + struct input_dev *input = dev->input; + int i; + + for (i = 0; i < bdev->pdata->nbuttons; i++) { + struct gpio_keys_button_data *bdata = &bdev->data[i]; + + if (bdata->count < bdata->threshold) + bdata->count++; + else + gpio_keys_polled_check_state(input, &pdata->buttons[i], + bdata); + } +} + +static void gpio_keys_polled_open(struct input_polled_dev *dev) +{ + struct gpio_keys_polled_dev *bdev = dev->private; + struct gpio_keys_platform_data *pdata = bdev->pdata; + + if (pdata->enable) + pdata->enable(bdev->dev); +} + +static void gpio_keys_polled_close(struct input_polled_dev *dev) +{ + struct gpio_keys_polled_dev *bdev = dev->private; + struct gpio_keys_platform_data *pdata = bdev->pdata; + + if (pdata->disable) + pdata->disable(bdev->dev); +} + +static int __devinit gpio_keys_polled_probe(struct platform_device *pdev) +{ + struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; + struct device *dev = &pdev->dev; + struct gpio_keys_polled_dev *bdev; + struct input_polled_dev *poll_dev; + struct input_dev *input; + int error; + int i; + + if (!pdata || !pdata->poll_interval) + return -EINVAL; + + bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) + + pdata->nbuttons * sizeof(struct gpio_keys_button_data), + GFP_KERNEL); + if (!bdev) { + dev_err(dev, "no memory for private data\n"); + return -ENOMEM; + } + + poll_dev = input_allocate_polled_device(); + if (!poll_dev) { + dev_err(dev, "no memory for polled device\n"); + error = -ENOMEM; + goto err_free_bdev; + } + + poll_dev->private = bdev; + poll_dev->poll = gpio_keys_polled_poll; + poll_dev->poll_interval = pdata->poll_interval; + poll_dev->open = gpio_keys_polled_open; + poll_dev->close = gpio_keys_polled_close; + + input = poll_dev->input; + + input->evbit[0] = BIT(EV_KEY); + input->name = pdev->name; + input->phys = DRV_NAME"/input0"; + input->dev.parent = &pdev->dev; + + input->id.bustype = BUS_HOST; + input->id.vendor = 0x0001; + input->id.product = 0x0001; + input->id.version = 0x0100; + + for (i = 0; i < pdata->nbuttons; i++) { + struct gpio_keys_button *button = &pdata->buttons[i]; + struct gpio_keys_button_data *bdata = &bdev->data[i]; + unsigned int gpio = button->gpio; + unsigned int type = button->type ?: EV_KEY; + + if (button->wakeup) { + dev_err(dev, DRV_NAME " does not support wakeup\n"); + error = -EINVAL; + goto err_free_gpio; + } + + error = gpio_request(gpio, + button->desc ? button->desc : DRV_NAME); + if (error) { + dev_err(dev, "unable to claim gpio %u, err=%d\n", + gpio, error); + goto err_free_gpio; + } + + error = gpio_direction_input(gpio); + if (error) { + dev_err(dev, + "unable to set direction on gpio %u, err=%d\n", + gpio, error); + goto err_free_gpio; + } + + bdata->can_sleep = gpio_cansleep(gpio); + bdata->last_state = -1; + bdata->threshold = DIV_ROUND_UP(button->debounce_interval, + pdata->poll_interval); + + input_set_capability(input, type, button->code); + } + + bdev->poll_dev = poll_dev; + bdev->dev = dev; + bdev->pdata = pdata; + platform_set_drvdata(pdev, bdev); + + error = input_register_polled_device(poll_dev); + if (error) { + dev_err(dev, "unable to register polled device, err=%d\n", + error); + goto err_free_gpio; + } + + /* report initial state of the buttons */ + for (i = 0; i < pdata->nbuttons; i++) + gpio_keys_polled_check_state(input, &pdata->buttons[i], + &bdev->data[i]); + + return 0; + +err_free_gpio: + while (--i >= 0) + gpio_free(pdata->buttons[i].gpio); + + input_free_polled_device(poll_dev); + +err_free_bdev: + kfree(bdev); + + platform_set_drvdata(pdev, NULL); + return error; +} + +static int __devexit gpio_keys_polled_remove(struct platform_device *pdev) +{ + struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev); + struct gpio_keys_platform_data *pdata = bdev->pdata; + int i; + + input_unregister_polled_device(bdev->poll_dev); + + for (i = 0; i < pdata->nbuttons; i++) + gpio_free(pdata->buttons[i].gpio); + + input_free_polled_device(bdev->poll_dev); + + kfree(bdev); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver gpio_keys_polled_driver = { + .probe = gpio_keys_polled_probe, + .remove = __devexit_p(gpio_keys_polled_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init gpio_keys_polled_init(void) +{ + return platform_driver_register(&gpio_keys_polled_driver); +} + +static void __exit gpio_keys_polled_exit(void) +{ + platform_driver_unregister(&gpio_keys_polled_driver); +} + +module_init(gpio_keys_polled_init); +module_exit(gpio_keys_polled_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_DESCRIPTION("Polled GPIO Buttons driver"); +MODULE_ALIAS("platform:" DRV_NAME); |