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
  34 ACPI_MODULE_NAME(MODULE_NAME);
  35
  36 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  37 MODULE_LICENSE("GPL");
  38
  39 static const struct acpi_device_id ebook_device_ids[] = {
  40         { XO15_EBOOK_HID, 0 },
  41         { "", 0 },
  42 };
  43 MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  44
  45 struct ebook_switch {
  46         struct input_dev *input;
  47         char phys[32];                  /* for input device */
  48 };
  49
  50 static 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
  66 static 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
  81 static int ebook_switch_resume(struct device *dev)
  82 {
  83         return ebook_send_state(to_acpi_device(dev));
  84 }
  85 #endif
  86
  87 static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  88
  89 static 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
 153 static 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
 162 static 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 };
 173 module_acpi_driver(xo15_ebook_driver);