262 lines
6.4 KiB
C
262 lines
6.4 KiB
C
/*
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* Driver for buttons on GPIO lines not capable of generating interrupts
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*
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* Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
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* Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
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*
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* This file was based on: /drivers/input/misc/cobalt_btns.c
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* Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
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*
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* also was based on: /drivers/input/keyboard/gpio_keys.c
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* Copyright 2005 Phil Blundell
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/input.h>
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#include <linux/input-polldev.h>
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#include <linux/ioport.h>
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#include <linux/platform_device.h>
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#include <linux/gpio.h>
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#include <linux/gpio_keys.h>
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#define DRV_NAME "gpio-keys-polled"
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struct gpio_keys_button_data {
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int last_state;
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int count;
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int threshold;
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int can_sleep;
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};
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struct gpio_keys_polled_dev {
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struct input_polled_dev *poll_dev;
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struct device *dev;
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struct gpio_keys_platform_data *pdata;
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struct gpio_keys_button_data data[0];
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};
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static void gpio_keys_polled_check_state(struct input_dev *input,
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struct gpio_keys_button *button,
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struct gpio_keys_button_data *bdata)
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{
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int state;
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if (bdata->can_sleep)
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state = !!gpio_get_value_cansleep(button->gpio);
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else
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state = !!gpio_get_value(button->gpio);
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if (state != bdata->last_state) {
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unsigned int type = button->type ?: EV_KEY;
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input_event(input, type, button->code,
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!!(state ^ button->active_low));
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input_sync(input);
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bdata->count = 0;
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bdata->last_state = state;
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}
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}
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static void gpio_keys_polled_poll(struct input_polled_dev *dev)
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{
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struct gpio_keys_polled_dev *bdev = dev->private;
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struct gpio_keys_platform_data *pdata = bdev->pdata;
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struct input_dev *input = dev->input;
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int i;
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for (i = 0; i < bdev->pdata->nbuttons; i++) {
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struct gpio_keys_button_data *bdata = &bdev->data[i];
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if (bdata->count < bdata->threshold)
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bdata->count++;
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else
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gpio_keys_polled_check_state(input, &pdata->buttons[i],
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bdata);
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}
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}
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static void gpio_keys_polled_open(struct input_polled_dev *dev)
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{
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struct gpio_keys_polled_dev *bdev = dev->private;
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struct gpio_keys_platform_data *pdata = bdev->pdata;
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if (pdata->enable)
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pdata->enable(bdev->dev);
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}
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static void gpio_keys_polled_close(struct input_polled_dev *dev)
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{
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struct gpio_keys_polled_dev *bdev = dev->private;
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struct gpio_keys_platform_data *pdata = bdev->pdata;
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if (pdata->disable)
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pdata->disable(bdev->dev);
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}
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static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
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{
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struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
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struct device *dev = &pdev->dev;
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struct gpio_keys_polled_dev *bdev;
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struct input_polled_dev *poll_dev;
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struct input_dev *input;
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int error;
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int i;
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if (!pdata || !pdata->poll_interval)
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return -EINVAL;
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bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
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pdata->nbuttons * sizeof(struct gpio_keys_button_data),
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GFP_KERNEL);
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if (!bdev) {
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dev_err(dev, "no memory for private data\n");
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return -ENOMEM;
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}
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poll_dev = input_allocate_polled_device();
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if (!poll_dev) {
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dev_err(dev, "no memory for polled device\n");
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error = -ENOMEM;
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goto err_free_bdev;
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}
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poll_dev->private = bdev;
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poll_dev->poll = gpio_keys_polled_poll;
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poll_dev->poll_interval = pdata->poll_interval;
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poll_dev->open = gpio_keys_polled_open;
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poll_dev->close = gpio_keys_polled_close;
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input = poll_dev->input;
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input->evbit[0] = BIT(EV_KEY);
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input->name = pdev->name;
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input->phys = DRV_NAME"/input0";
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input->dev.parent = &pdev->dev;
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input->id.bustype = BUS_HOST;
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input->id.vendor = 0x0001;
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input->id.product = 0x0001;
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input->id.version = 0x0100;
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for (i = 0; i < pdata->nbuttons; i++) {
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struct gpio_keys_button *button = &pdata->buttons[i];
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struct gpio_keys_button_data *bdata = &bdev->data[i];
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unsigned int gpio = button->gpio;
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unsigned int type = button->type ?: EV_KEY;
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if (button->wakeup) {
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dev_err(dev, DRV_NAME " does not support wakeup\n");
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error = -EINVAL;
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goto err_free_gpio;
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}
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error = gpio_request(gpio,
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button->desc ? button->desc : DRV_NAME);
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if (error) {
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dev_err(dev, "unable to claim gpio %u, err=%d\n",
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gpio, error);
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goto err_free_gpio;
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}
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error = gpio_direction_input(gpio);
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if (error) {
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dev_err(dev,
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"unable to set direction on gpio %u, err=%d\n",
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gpio, error);
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goto err_free_gpio;
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}
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bdata->can_sleep = gpio_cansleep(gpio);
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bdata->last_state = -1;
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bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
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pdata->poll_interval);
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input_set_capability(input, type, button->code);
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}
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bdev->poll_dev = poll_dev;
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bdev->dev = dev;
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bdev->pdata = pdata;
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platform_set_drvdata(pdev, bdev);
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error = input_register_polled_device(poll_dev);
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if (error) {
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dev_err(dev, "unable to register polled device, err=%d\n",
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error);
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goto err_free_gpio;
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}
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/* report initial state of the buttons */
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for (i = 0; i < pdata->nbuttons; i++)
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gpio_keys_polled_check_state(input, &pdata->buttons[i],
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&bdev->data[i]);
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return 0;
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err_free_gpio:
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while (--i >= 0)
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gpio_free(pdata->buttons[i].gpio);
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input_free_polled_device(poll_dev);
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err_free_bdev:
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kfree(bdev);
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platform_set_drvdata(pdev, NULL);
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return error;
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}
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static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
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{
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struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
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struct gpio_keys_platform_data *pdata = bdev->pdata;
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int i;
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input_unregister_polled_device(bdev->poll_dev);
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for (i = 0; i < pdata->nbuttons; i++)
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gpio_free(pdata->buttons[i].gpio);
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input_free_polled_device(bdev->poll_dev);
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kfree(bdev);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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static struct platform_driver gpio_keys_polled_driver = {
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.probe = gpio_keys_polled_probe,
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.remove = __devexit_p(gpio_keys_polled_remove),
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.driver = {
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.name = DRV_NAME,
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.owner = THIS_MODULE,
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},
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};
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static int __init gpio_keys_polled_init(void)
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{
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return platform_driver_register(&gpio_keys_polled_driver);
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}
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static void __exit gpio_keys_polled_exit(void)
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{
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platform_driver_unregister(&gpio_keys_polled_driver);
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}
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module_init(gpio_keys_polled_init);
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module_exit(gpio_keys_polled_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
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MODULE_DESCRIPTION("Polled GPIO Buttons driver");
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MODULE_ALIAS("platform:" DRV_NAME);
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