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 <acpi/acpi_bus.h>
  22#include <acpi/acpi_drivers.h>
  23
  24#define MODULE_NAME "xo15-ebook"
  25
  26#define XO15_EBOOK_CLASS                MODULE_NAME
  27#define XO15_EBOOK_TYPE_UNKNOWN 0x00
  28#define XO15_EBOOK_NOTIFY_STATUS        0x80
  29
  30#define XO15_EBOOK_SUBCLASS             "ebook"
  31#define XO15_EBOOK_HID                  "XO15EBK"
  32#define XO15_EBOOK_DEVICE_NAME          "EBook Switch"
  33
  34ACPI_MODULE_NAME(MODULE_NAME);
  35
  36MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  37MODULE_LICENSE("GPL");
  38
  39static const struct acpi_device_id ebook_device_ids[] = {
  40        { XO15_EBOOK_HID, 0 },
  41        { "", 0 },
  42};
  43MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  44
  45struct ebook_switch {
  46        struct input_dev *input;
  47        char phys[32];                  /* for input device */
  48};
  49
  50static int ebook_send_state(struct acpi_device *device)
  51{
  52        struct ebook_switch *button = acpi_driver_data(device);
  53        unsigned long long state;
  54        acpi_status status;
  55
  56        status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
  57        if (ACPI_FAILURE(status))
  58                return -EIO;
  59
  60        /* input layer checks if event is redundant */
  61        input_report_switch(button->input, SW_TABLET_MODE, !state);
  62        input_sync(button->input);
  63        return 0;
  64}
  65
  66static void ebook_switch_notify(struct acpi_device *device, u32 event)
  67{
  68        switch (event) {
  69        case ACPI_FIXED_HARDWARE_EVENT:
  70        case XO15_EBOOK_NOTIFY_STATUS:
  71                ebook_send_state(device);
  72                break;
  73        default:
  74                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  75                                  "Unsupported event [0x%x]\n", event));
  76                break;
  77        }
  78}
  79
  80#ifdef CONFIG_PM_SLEEP
  81static int ebook_switch_resume(struct device *dev)
  82{
  83        return ebook_send_state(to_acpi_device(dev));
  84}
  85#endif
  86
  87static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  88
  89static int ebook_switch_add(struct acpi_device *device)
  90{
  91        struct ebook_switch *button;
  92        struct input_dev *input;
  93        const char *hid = acpi_device_hid(device);
  94        char *name, *class;
  95        int error;
  96
  97        button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
  98        if (!button)
  99                return -ENOMEM;
 100
 101        device->driver_data = button;
 102
 103        button->input = input = input_allocate_device();
 104        if (!input) {
 105                error = -ENOMEM;
 106                goto err_free_button;
 107        }
 108
 109        name = acpi_device_name(device);
 110        class = acpi_device_class(device);
 111
 112        if (strcmp(hid, XO15_EBOOK_HID)) {
 113                pr_err("Unsupported hid [%s]\n", hid);
 114                error = -ENODEV;
 115                goto err_free_input;
 116        }
 117
 118        strcpy(name, XO15_EBOOK_DEVICE_NAME);
 119        sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
 120
 121        snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 122
 123        input->name = name;
 124        input->phys = button->phys;
 125        input->id.bustype = BUS_HOST;
 126        input->dev.parent = &device->dev;
 127
 128        input->evbit[0] = BIT_MASK(EV_SW);
 129        set_bit(SW_TABLET_MODE, input->swbit);
 130
 131        error = input_register_device(input);
 132        if (error)
 133                goto err_free_input;
 134
 135        ebook_send_state(device);
 136
 137        if (device->wakeup.flags.valid) {
 138                /* Button's GPE is run-wake GPE */
 139                acpi_enable_gpe(device->wakeup.gpe_device,
 140                                device->wakeup.gpe_number);
 141                device_set_wakeup_enable(&device->dev, true);
 142        }
 143
 144        return 0;
 145
 146 err_free_input:
 147        input_free_device(input);
 148 err_free_button:
 149        kfree(button);
 150        return error;
 151}
 152
 153static int ebook_switch_remove(struct acpi_device *device)
 154{
 155        struct ebook_switch *button = acpi_driver_data(device);
 156
 157        input_unregister_device(button->input);
 158        kfree(button);
 159        return 0;
 160}
 161
 162static struct acpi_driver xo15_ebook_driver = {
 163        .name = MODULE_NAME,
 164        .class = XO15_EBOOK_CLASS,
 165        .ids = ebook_device_ids,
 166        .ops = {
 167                .add = ebook_switch_add,
 168                .remove = ebook_switch_remove,
 169                .notify = ebook_switch_notify,
 170        },
 171        .drv.pm = &ebook_switch_pm,
 172};
 173module_acpi_driver(xo15_ebook_driver);
 174