cobalt_btns.c

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/*
 *  Cobalt button interface driver.
 *
 *  Copyright (C) 2007-2008  Yoichi Yuasa <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include <linux/init.h>
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define BUTTONS_POLL_INTERVAL   30  /* msec */
#define BUTTONS_COUNT_THRESHOLD 3
#define BUTTONS_STATUS_MASK 0xfe000000

static const unsigned short cobalt_map[] = {
    KEY_RESERVED,
    KEY_RESTART,
    KEY_LEFT,
    KEY_UP,
    KEY_DOWN,
    KEY_RIGHT,
    KEY_ENTER,
    KEY_SELECT
};

struct buttons_dev {
    struct input_polled_dev *poll_dev;
    unsigned short keymap[ARRAY_SIZE(cobalt_map)];
    int count[ARRAY_SIZE(cobalt_map)];
    void __iomem *reg;
};

static void handle_buttons(struct input_polled_dev *dev)
{
    struct buttons_dev *bdev = dev->private;
    struct input_dev *input = dev->input;
    uint32_t status;
    int i;

    status = ~readl(bdev->reg) >> 24;

    for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
        if (status & (1U << i)) {
            if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
                input_event(input, EV_MSC, MSC_SCAN, i);
                input_report_key(input, bdev->keymap[i], 1);
                input_sync(input);
            }
        } else {
            if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
                input_event(input, EV_MSC, MSC_SCAN, i);
                input_report_key(input, bdev->keymap[i], 0);
                input_sync(input);
            }
            bdev->count[i] = 0;
        }
    }
}

static int __devinit cobalt_buttons_probe(struct platform_device *pdev)
{
    struct buttons_dev *bdev;
    struct input_polled_dev *poll_dev;
    struct input_dev *input;
    struct resource *res;
    int error, i;

    bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
    poll_dev = input_allocate_polled_device();
    if (!bdev || !poll_dev) {
        error = -ENOMEM;
        goto err_free_mem;
    }

    memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));

    poll_dev->private = bdev;
    poll_dev->poll = handle_buttons;
    poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;

    input = poll_dev->input;
    input->name = "Cobalt buttons";
    input->phys = "cobalt/input0";
    input->id.bustype = BUS_HOST;
    input->dev.parent = &pdev->dev;

    input->keycode = bdev->keymap;
    input->keycodemax = ARRAY_SIZE(bdev->keymap);
    input->keycodesize = sizeof(unsigned short);

    input_set_capability(input, EV_MSC, MSC_SCAN);
    __set_bit(EV_KEY, input->evbit);
    for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
        __set_bit(bdev->keymap[i], input->keybit);
    __clear_bit(KEY_RESERVED, input->keybit);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        error = -EBUSY;
        goto err_free_mem;
    }

    bdev->poll_dev = poll_dev;
    bdev->reg = ioremap(res->start, resource_size(res));
    dev_set_drvdata(&pdev->dev, bdev);

    error = input_register_polled_device(poll_dev);
    if (error)
        goto err_iounmap;

    return 0;

 err_iounmap:
    iounmap(bdev->reg);
 err_free_mem:
    input_free_polled_device(poll_dev);
    kfree(bdev);
    dev_set_drvdata(&pdev->dev, NULL);
    return error;
}

static int __devexit cobalt_buttons_remove(struct platform_device *pdev)
{
    struct device *dev = &pdev->dev;
    struct buttons_dev *bdev = dev_get_drvdata(dev);

    input_unregister_polled_device(bdev->poll_dev);
    input_free_polled_device(bdev->poll_dev);
    iounmap(bdev->reg);
    kfree(bdev);
    dev_set_drvdata(dev, NULL);

    return 0;
}

MODULE_AUTHOR("Yoichi Yuasa <[email protected]>");
MODULE_DESCRIPTION("Cobalt button interface driver");
MODULE_LICENSE("GPL");
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:Cobalt buttons");

static struct platform_driver cobalt_buttons_driver = {
    .probe  = cobalt_buttons_probe,
    .remove = __devexit_p(cobalt_buttons_remove),
    .driver = {
        .name   = "Cobalt buttons",
        .owner  = THIS_MODULE,
    },
};
module_platform_driver(cobalt_buttons_driver);