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
  29ACPI_MODULE_NAME(MODULE_NAME);
  30
  31MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver");
  32MODULE_LICENSE("GPL");
  33
  34static const struct acpi_device_id ebook_device_ids[] = {
  35        { XO15_EBOOK_HID, 0 },
  36        { "", 0 },
  37};
  38MODULE_DEVICE_TABLE(acpi, ebook_device_ids);
  39
  40struct ebook_switch {
  41        struct input_dev *input;
  42        char phys[32];                  /* for input device */
  43};
  44
  45static 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
  61static 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
  76static int ebook_switch_resume(struct device *dev)
  77{
  78        return ebook_send_state(to_acpi_device(dev));
  79}
  80#endif
  81
  82static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume);
  83
  84static 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
 148static 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
 157static 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};
 168module_acpi_driver(xo15_ebook_driver);
 169