atlas_btns.c

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/*
 *  atlas_btns.c - Atlas Wallmount Touchscreen ACPI Extras
 *
 *  Copyright (C) 2006 Jaya Kumar
 *  Based on Toshiba ACPI by John Belmonte and ASUS ACPI
 *  This work was sponsored by CIS(M) Sdn Bhd.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/types.h>
#include <asm/uaccess.h>
#include <acpi/acpi_drivers.h>

#define ACPI_ATLAS_NAME     "Atlas ACPI"
#define ACPI_ATLAS_CLASS    "Atlas"

static unsigned short atlas_keymap[16];
static struct input_dev *input_dev;

/* button handling code */
static acpi_status acpi_atlas_button_setup(acpi_handle region_handle,
            u32 function, void *handler_context, void **return_context)
{
    *return_context =
        (function != ACPI_REGION_DEACTIVATE) ? handler_context : NULL;

    return AE_OK;
}

static acpi_status acpi_atlas_button_handler(u32 function,
              acpi_physical_address address,
              u32 bit_width, u64 *value,
              void *handler_context, void *region_context)
{
    acpi_status status;

    if (function == ACPI_WRITE) {
        int code = address & 0x0f;
        int key_down = !(address & 0x10);

        input_event(input_dev, EV_MSC, MSC_SCAN, code);
        input_report_key(input_dev, atlas_keymap[code], key_down);
        input_sync(input_dev);

        status = AE_OK;
    } else {
        pr_warn("shrugged on unexpected function: function=%x,address=%lx,value=%x\n",
            function, (unsigned long)address, (u32)*value);
        status = AE_BAD_PARAMETER;
    }

    return status;
}

static int atlas_acpi_button_add(struct acpi_device *device)
{
    acpi_status status;
    int i;
    int err;

    input_dev = input_allocate_device();
    if (!input_dev) {
        pr_err("unable to allocate input device\n");
        return -ENOMEM;
    }

    input_dev->name = "Atlas ACPI button driver";
    input_dev->phys = "ASIM0000/atlas/input0";
    input_dev->id.bustype = BUS_HOST;
    input_dev->keycode = atlas_keymap;
    input_dev->keycodesize = sizeof(unsigned short);
    input_dev->keycodemax = ARRAY_SIZE(atlas_keymap);

    input_set_capability(input_dev, EV_MSC, MSC_SCAN);
    __set_bit(EV_KEY, input_dev->evbit);
    for (i = 0; i < ARRAY_SIZE(atlas_keymap); i++) {
        if (i < 9) {
            atlas_keymap[i] = KEY_F1 + i;
            __set_bit(KEY_F1 + i, input_dev->keybit);
        } else
            atlas_keymap[i] = KEY_RESERVED;
    }

    err = input_register_device(input_dev);
    if (err) {
        pr_err("couldn't register input device\n");
        input_free_device(input_dev);
        return err;
    }

    /* hookup button handler */
    status = acpi_install_address_space_handler(device->handle,
                0x81, &acpi_atlas_button_handler,
                &acpi_atlas_button_setup, device);
    if (ACPI_FAILURE(status)) {
        pr_err("error installing addr spc handler\n");
        input_unregister_device(input_dev);
        err = -EINVAL;
    }

    return err;
}

static int atlas_acpi_button_remove(struct acpi_device *device, int type)
{
    acpi_status status;

    status = acpi_remove_address_space_handler(device->handle,
                0x81, &acpi_atlas_button_handler);
    if (ACPI_FAILURE(status))
        pr_err("error removing addr spc handler\n");

    input_unregister_device(input_dev);

    return 0;
}

static const struct acpi_device_id atlas_device_ids[] = {
    {"ASIM0000", 0},
    {"", 0},
};
MODULE_DEVICE_TABLE(acpi, atlas_device_ids);

static struct acpi_driver atlas_acpi_driver = {
    .name   = ACPI_ATLAS_NAME,
    .class  = ACPI_ATLAS_CLASS,
    .owner  = THIS_MODULE,
    .ids    = atlas_device_ids,
    .ops    = {
        .add    = atlas_acpi_button_add,
        .remove = atlas_acpi_button_remove,
    },
};
module_acpi_driver(atlas_acpi_driver);

MODULE_AUTHOR("Jaya Kumar");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Atlas button driver");