drivers/platform/x86/xo15-ebook.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  OLPC XO-1.5 ebook switch driver
   4  *  (based on generic ACPI button driver)
   5  *
   6  *  Copyright (C) 2009 Paul Fox <pgf@laptop.org>
   7  *  Copyright (C) 2010 One Laptop per Child
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/input.h>
  17 #include <linux/acpi.h>
  18
  19 #define MODULE_NAME "xo15-ebook"
  20
  21 #define XO15_EBOOK_CLASS                MODULE_NAME
  22 #define XO15_EBOOK_TYPE_UNKNOWN 0x00
  23 #define XO15_EBOOK_NOTIFY_STATUS        0x80
  24
  25 #define XO15_EBOOK_SUBCLASS             "ebook"
  26 #define XO15_EBOOK_HID                  "XO15EBK"
  27 #define XO15_EBOOK_DEVICE_NAME          "EBook Switch"
  28
  29 ACPI_MODULE_NAME(MODULE_NAME);
  30
  31 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  32 MODULE_LICENSE("GPL");
  33
  34 static const struct acpi_device_id ebook_device_ids[] = {
  35         { XO15_EBOOK_HID, 0 },
  36         { "", 0 },
  37 };
  38 MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  39
  40 struct ebook_switch {
  41         struct input_dev *input;
  42         char phys[32];                  /* for input device */
  43 };
  44
  45 static int ebook_send_state(struct acpi_device *device)
  46 {
  47         struct ebook_switch *button = acpi_driver_data(device);
  48         unsigned long long state;
  49         acpi_status status;
  50
  51         status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state);
  52         if (ACPI_FAILURE(status))
  53                 return -EIO;
  54
  55         /* input layer checks if event is redundant */
  56         input_report_switch(button->input, SW_TABLET_MODE, !state);
  57         input_sync(button->input);
  58         return 0;
  59 }
  60
  61 static void ebook_switch_notify(struct acpi_device *device, u32 event)
  62 {
  63         switch (event) {
  64         case ACPI_FIXED_HARDWARE_EVENT:
  65         case XO15_EBOOK_NOTIFY_STATUS:
  66                 ebook_send_state(device);
  67                 break;
  68         default:
  69                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  70                                   "Unsupported event [0x%x]\n", event));
  71                 break;
  72         }
  73 }
  74
  75 #ifdef CONFIG_PM_SLEEP
  76 static int ebook_switch_resume(struct device *dev)
  77 {
  78         return ebook_send_state(to_acpi_device(dev));
  79 }
  80 #endif
  81
  82 static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  83
  84 static int ebook_switch_add(struct acpi_device *device)
  85 {
  86         struct ebook_switch *button;
  87         struct input_dev *input;
  88         const char *hid = acpi_device_hid(device);
  89         char *name, *class;
  90         int error;
  91
  92         button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL);
  93         if (!button)
  94                 return -ENOMEM;
  95
  96         device->driver_data = button;
  97
  98         button->input = input = input_allocate_device();
  99         if (!input) {
 100                 error = -ENOMEM;
 101                 goto err_free_button;
 102         }
 103
 104         name = acpi_device_name(device);
 105         class = acpi_device_class(device);
 106
 107         if (strcmp(hid, XO15_EBOOK_HID)) {
 108                 pr_err("Unsupported hid [%s]\n", hid);
 109                 error = -ENODEV;
 110                 goto err_free_input;
 111         }
 112
 113         strcpy(name, XO15_EBOOK_DEVICE_NAME);
 114         sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS);
 115
 116         snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 117
 118         input->name = name;
 119         input->phys = button->phys;
 120         input->id.bustype = BUS_HOST;
 121         input->dev.parent = &device->dev;
 122
 123         input->evbit[0] = BIT_MASK(EV_SW);
 124         set_bit(SW_TABLET_MODE, input->swbit);
 125
 126         error = input_register_device(input);
 127         if (error)
 128                 goto err_free_input;
 129
 130         ebook_send_state(device);
 131
 132         if (device->wakeup.flags.valid) {
 133                 /* Button's GPE is run-wake GPE */
 134                 acpi_enable_gpe(device->wakeup.gpe_device,
 135                                 device->wakeup.gpe_number);
 136                 device_set_wakeup_enable(&device->dev, true);
 137         }
 138
 139         return 0;
 140
 141  err_free_input:
 142         input_free_device(input);
 143  err_free_button:
 144         kfree(button);
 145         return error;
 146 }
 147
 148 static int ebook_switch_remove(struct acpi_device *device)
 149 {
 150         struct ebook_switch *button = acpi_driver_data(device);
 151
 152         input_unregister_device(button->input);
 153         kfree(button);
 154         return 0;
 155 }
 156
 157 static struct acpi_driver xo15_ebook_driver = {
 158         .name = MODULE_NAME,
 159         .class = XO15_EBOOK_CLASS,
 160         .ids = ebook_device_ids,
 161         .ops = {
 162                 .add = ebook_switch_add,
 163                 .remove = ebook_switch_remove,
 164                 .notify = ebook_switch_notify,
 165         },
 166         .drv.pm = &ebook_switch_pm,
 167 };
 168 module_acpi_driver(xo15_ebook_driver);