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