diff options
Diffstat (limited to 'drivers/input/keyboard/gpio_keys_polled.c')
| -rw-r--r-- | drivers/input/keyboard/gpio_keys_polled.c | 319 |
1 files changed, 319 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 00000000000..432d36395f3 --- /dev/null +++ b/drivers/input/keyboard/gpio_keys_polled.c @@ -0,0 +1,319 @@ +/* + * 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/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> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.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; + const 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; + const struct gpio_keys_platform_data *pdata = bdev->pdata; + struct input_dev *input = dev->input; + int i; + + for (i = 0; i < 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; + const 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; + const struct gpio_keys_platform_data *pdata = bdev->pdata; + + if (pdata->disable) + pdata->disable(bdev->dev); +} + +#ifdef CONFIG_OF +static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct device *dev) +{ + struct device_node *node, *pp; + struct gpio_keys_platform_data *pdata; + struct gpio_keys_button *button; + int error; + int nbuttons; + int i; + + node = dev->of_node; + if (!node) + return NULL; + + nbuttons = of_get_child_count(node); + if (nbuttons == 0) + return NULL; + + pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button), + GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + pdata->buttons = (struct gpio_keys_button *)(pdata + 1); + pdata->nbuttons = nbuttons; + + pdata->rep = !!of_get_property(node, "autorepeat", NULL); + of_property_read_u32(node, "poll-interval", &pdata->poll_interval); + + i = 0; + for_each_child_of_node(node, pp) { + int gpio; + enum of_gpio_flags flags; + + if (!of_find_property(pp, "gpios", NULL)) { + pdata->nbuttons--; + dev_warn(dev, "Found button without gpios\n"); + continue; + } + + gpio = of_get_gpio_flags(pp, 0, &flags); + if (gpio < 0) { + error = gpio; + if (error != -EPROBE_DEFER) + dev_err(dev, + "Failed to get gpio flags, error: %d\n", + error); + return ERR_PTR(error); + } + + button = &pdata->buttons[i++]; + + button->gpio = gpio; + button->active_low = flags & OF_GPIO_ACTIVE_LOW; + + if (of_property_read_u32(pp, "linux,code", &button->code)) { + dev_err(dev, "Button without keycode: 0x%x\n", + button->gpio); + return ERR_PTR(-EINVAL); + } + + button->desc = of_get_property(pp, "label", NULL); + + if (of_property_read_u32(pp, "linux,input-type", &button->type)) + button->type = EV_KEY; + + button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL); + + if (of_property_read_u32(pp, "debounce-interval", + &button->debounce_interval)) + button->debounce_interval = 5; + } + + if (pdata->nbuttons == 0) + return ERR_PTR(-EINVAL); + + return pdata; +} + +static const struct of_device_id gpio_keys_polled_of_match[] = { + { .compatible = "gpio-keys-polled", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match); + +#else + +static inline struct gpio_keys_platform_data * +gpio_keys_polled_get_devtree_pdata(struct device *dev) +{ + return NULL; +} +#endif + +static int gpio_keys_polled_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev); + struct gpio_keys_polled_dev *bdev; + struct input_polled_dev *poll_dev; + struct input_dev *input; + size_t size; + int error; + int i; + + if (!pdata) { + pdata = gpio_keys_polled_get_devtree_pdata(dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + if (!pdata) { + dev_err(dev, "missing platform data\n"); + return -EINVAL; + } + } + + if (!pdata->poll_interval) { + dev_err(dev, "missing poll_interval value\n"); + return -EINVAL; + } + + size = sizeof(struct gpio_keys_polled_dev) + + pdata->nbuttons * sizeof(struct gpio_keys_button_data); + bdev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL); + if (!bdev) { + dev_err(dev, "no memory for private data\n"); + return -ENOMEM; + } + + poll_dev = devm_input_allocate_polled_device(&pdev->dev); + if (!poll_dev) { + dev_err(dev, "no memory for polled device\n"); + return -ENOMEM; + } + + 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->name = pdev->name; + input->phys = DRV_NAME"/input0"; + + input->id.bustype = BUS_HOST; + input->id.vendor = 0x0001; + input->id.product = 0x0001; + input->id.version = 0x0100; + + __set_bit(EV_KEY, input->evbit); + if (pdata->rep) + __set_bit(EV_REP, input->evbit); + + 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"); + return -EINVAL; + } + + error = devm_gpio_request_one(&pdev->dev, gpio, GPIOF_IN, + button->desc ? : DRV_NAME); + if (error) { + dev_err(dev, "unable to claim gpio %u, err=%d\n", + gpio, error); + return error; + } + + 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); + return error; + } + + /* 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; +} + +static struct platform_driver gpio_keys_polled_driver = { + .probe = gpio_keys_polled_probe, + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(gpio_keys_polled_of_match), + }, +}; +module_platform_driver(gpio_keys_polled_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_DESCRIPTION("Polled GPIO Buttons driver"); +MODULE_ALIAS("platform:" DRV_NAME); |