LXR linux/drivers/platform/x86/xo15-ebook.c

   1/*
   2 *  OLPC XO-1.5 ebook switch driver
   3 *  (based on generic ACPI button driver)
   4 *
   5 *  Copyright (C) 2009 Paul Fox <pgf@laptop.org>
   6 *  Copyright (C) 2010 One Laptop per Child
   7 *
   8 *  This program is free software; you can redistribute it and/or modify
   9 *  it under the terms of the GNU General Public License as published by
  10 *  the Free Software Foundation; either version 2 of the License, or (at
  11 *  your option) any later version.
  12 */
  13
  14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/init.h>
  19#include <linux/types.h>
  20#include <linux/input.h>
  21#include <linux/acpi.h>
  22
  23#define MODULE_NAME "xo15-ebook"
  24
  25#define XO15_EBOOK_CLASS                MODULE_NAME
  26#define XO15_EBOOK_TYPE_UNKNOWN 0x00
  27#define XO15_EBOOK_NOTIFY_STATUS        0x80
  28
  29#define XO15_EBOOK_SUBCLASS             "ebook"
  30#define XO15_EBOOK_HID                  "XO15EBK"
  31#define XO15_EBOOK_DEVICE_NAME          "EBook Switch"
  32
  33ACPI_MODULE_NAME(MODULE_NAME);
  34
  35MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  36MODULE_LICENSE("GPL");
  37
  38static const struct acpi_device_id ebook_device_ids[] = {
  39        { XO15_EBOOK_HID, 0 },
  40        { "", 0 },
  41};
  42MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  43
  44struct ebook_switch {
  45        struct input_dev *input;
  46        char phys[32];                  /* for input device */
  47};
  48
  49static int ebook_send_state(struct acpi_device *device)
  50{
  51        struct ebook_switch *button = acpi_driver_data(device);
  52        unsigned long long state;
  53        acpi_status status;
  54
  55        status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
  56        if (ACPI_FAILURE(status))
  57                return -EIO;
  58
  59        /* input layer checks if event is redundant */
  60        input_report_switch(button->input, SW_TABLET_MODE, !state);
  61        input_sync(button->input);
  62        return 0;
  63}
  64
  65static void ebook_switch_notify(struct acpi_device *device, u32 event)
  66{
  67        switch (event) {
  68        case ACPI_FIXED_HARDWARE_EVENT:
  69        case XO15_EBOOK_NOTIFY_STATUS:
  70                ebook_send_state(device);
  71                break;
  72        default:
  73                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  74                                  "Unsupported event [0x%x]\n", event));
  75                break;
  76        }
  77}
  78
  79#ifdef CONFIG_PM_SLEEP
  80static int ebook_switch_resume(struct device *dev)
  81{
  82        return ebook_send_state(to_acpi_device(dev));
  83}
  84#endif
  85
  86static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  87
  88static int ebook_switch_add(struct acpi_device *device)
  89{
  90        struct ebook_switch *button;
  91        struct input_dev *input;
  92        const char *hid = acpi_device_hid(device);
  93        char *name, *class;
  94        int error;
  95
  96        button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
  97        if (!button)
  98                return -ENOMEM;
  99
 100        device->driver_data = button;
 101
 102        button->input = input = input_allocate_device();
 103        if (!input) {
 104                error = -ENOMEM;
 105                goto err_free_button;
 106        }
 107
 108        name = acpi_device_name(device);
 109        class = acpi_device_class(device);
 110
 111        if (strcmp(hid, XO15_EBOOK_HID)) {
 112                pr_err("Unsupported hid [%s]\n", hid);
 113                error = -ENODEV;
 114                goto err_free_input;
 115        }
 116
 117        strcpy(name, XO15_EBOOK_DEVICE_NAME);
 118        sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
 119
 120        snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 121
 122        input->name = name;
 123        input->phys = button->phys;
 124        input->id.bustype = BUS_HOST;
 125        input->dev.parent = &device->dev;
 126
 127        input->evbit[0] = BIT_MASK(EV_SW);
 128        set_bit(SW_TABLET_MODE, input->swbit);
 129
 130        error = input_register_device(input);
 131        if (error)
 132                goto err_free_input;
 133
 134        ebook_send_state(device);
 135
 136        if (device->wakeup.flags.valid) {
 137                /* Button's GPE is run-wake GPE */
 138                acpi_enable_gpe(device->wakeup.gpe_device,
 139                                device->wakeup.gpe_number);
 140                device_set_wakeup_enable(&device->dev, true);
 141        }
 142
 143        return 0;
 144
 145 err_free_input:
 146        input_free_device(input);
 147 err_free_button:
 148        kfree(button);
 149        return error;
 150}
 151
 152static int ebook_switch_remove(struct acpi_device *device)
 153{
 154        struct ebook_switch *button = acpi_driver_data(device);
 155
 156        input_unregister_device(button->input);
 157        kfree(button);
 158        return 0;
 159}
 160
 161static struct acpi_driver xo15_ebook_driver = {
 162        .name = MODULE_NAME,
 163        .class = XO15_EBOOK_CLASS,
 164        .ids = ebook_device_ids,
 165        .ops = {
 166                .add = ebook_switch_add,
 167                .remove = ebook_switch_remove,
 168                .notify = ebook_switch_notify,
 169        },
 170        .drv.pm = &ebook_switch_pm,
 171};
 172module_acpi_driver(xo15_ebook_driver);
 173