LXR linux/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
  29MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  30MODULE_LICENSE("GPL");
  31
  32static const struct acpi_device_id ebook_device_ids[] = {
  33        { XO15_EBOOK_HID, 0 },
  34        { "", 0 },
  35};
  36MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  37
  38struct ebook_switch {
  39        struct input_dev *input;
  40        char phys[32];                  /* for input device */
  41};
  42
  43static 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
  59static 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
  74static int ebook_switch_resume(struct device *dev)
  75{
  76        return ebook_send_state(to_acpi_device(dev));
  77}
  78#endif
  79
  80static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  81
  82static 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
 146static 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
 155static 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};
 166module_acpi_driver(xo15_ebook_driver);
 167