diff options
Diffstat (limited to 'target/linux/generic-2.6/files/drivers/input')
| -rw-r--r-- | target/linux/generic-2.6/files/drivers/input/misc/gpio_buttons.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/files/drivers/input/misc/gpio_buttons.c b/target/linux/generic-2.6/files/drivers/input/misc/gpio_buttons.c new file mode 100644 index 000000000..0d219ff7c --- /dev/null +++ b/target/linux/generic-2.6/files/drivers/input/misc/gpio_buttons.c @@ -0,0 +1,206 @@ +/* + * Driver for buttons on GPIO lines not capable of generating interrupts + * + * Copyright (C) 2007,2008 Gabor Juhos <juhosg at openwrt.org> + * + * 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/init.h> +#include <linux/input-polldev.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <linux/gpio_buttons.h> + +#include <asm/gpio.h> + +#define DRV_NAME "gpio-buttons" +#define DRV_VERSION "0.1.0" +#define PFX DRV_NAME ": " + +struct gpio_buttons_dev { + struct input_polled_dev *poll_dev; + struct gpio_buttons_platform_data *pdata; +}; + +static void gpio_buttons_poll(struct input_polled_dev *dev) +{ + struct gpio_buttons_dev *bdev = dev->private; + struct gpio_buttons_platform_data *pdata = bdev->pdata; + struct input_dev *input = dev->input; + int i; + + for (i = 0; i < bdev->pdata->nbuttons; i++) { + struct gpio_button *button = &pdata->buttons[i]; + unsigned int type = button->type ?: EV_KEY; + int state; + + state = gpio_get_value(button->gpio) ? 1 : 0; + state ^= button->active_low; + + if (state) { + button->count++; + } else { + if (button->count >= button->threshold) { + input_event(input, type, button->code, 1); + input_sync(input); + } + button->count = 0; + } + + if (button->count == button->threshold) { + input_event(input, type, button->code, 0); + input_sync(input); + } + } +} + +static int __devinit gpio_buttons_probe(struct platform_device *pdev) +{ + struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data; + struct gpio_buttons_dev *bdev; + struct input_polled_dev *poll_dev; + struct input_dev *input; + int error, i; + + + if (!pdata) + return -ENXIO; + + bdev = kzalloc(sizeof(*bdev), GFP_KERNEL); + if (!bdev) { + pr_err(DRV_NAME "no memory for device\n"); + return -ENOMEM; + } + + poll_dev = input_allocate_polled_device(); + if (!poll_dev) { + pr_err(DRV_NAME "no memory for polled device\n"); + error = -ENOMEM; + goto err_free_bdev; + } + + poll_dev->private = bdev; + poll_dev->poll = gpio_buttons_poll; + poll_dev->poll_interval = pdata->poll_interval; + + input = poll_dev->input; + + input->evbit[0] = BIT_MASK(EV_KEY); + input->name = pdev->name; + input->phys = "gpio-buttons/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_button *button = &pdata->buttons[i]; + unsigned int gpio = button->gpio; + unsigned int type = button->type ?: EV_KEY; + + error = gpio_request(gpio, button->desc ? + button->desc : DRV_NAME); + if (error) { + pr_err(PFX "unable to claim gpio %u, error %d\n", + gpio, error); + goto err_free_gpio; + } + + error = gpio_direction_input(gpio); + if (error) { + pr_err(PFX "unable to set direction on gpio %u, " + "error %d\n", gpio, error); + goto err_free_gpio; + } + + input_set_capability(input, type, button->code); + button->count = 0; + } + + bdev->poll_dev = poll_dev; + bdev->pdata = pdata; + platform_set_drvdata(pdev, bdev); + + error = input_register_polled_device(poll_dev); + if (error) { + pr_err(PFX "unable to register polled device, error %d\n", + error); + goto err_free_gpio; + } + + return 0; + +err_free_gpio: + for (i = i - 1; i >= 0; i--) + gpio_free(pdata->buttons[i].gpio); + + input_free_polled_device(poll_dev); + +err_free_bdev: + kfree(bdev); +err: + platform_set_drvdata(pdev, NULL); + return error; +} + +static int __devexit gpio_buttons_remove(struct platform_device *pdev) +{ + struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev); + struct gpio_buttons_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_buttons_driver = { + .probe = gpio_buttons_probe, + .remove = __devexit_p(gpio_buttons_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init gpio_buttons_init(void) +{ + pr_info(DRV_NAME " driver version " DRV_VERSION "\n"); + return platform_driver_register(&gpio_buttons_driver); +} + +static void __exit gpio_buttons_exit(void) +{ + platform_driver_unregister(&gpio_buttons_driver); +} + +module_init(gpio_buttons_init); +module_exit(gpio_buttons_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); +MODULE_VERSION(DRV_VERSION); +MODULE_DESCRIPTION("Polled buttons driver for CPU GPIOs"); + |