drivers/input/misc/atlas_btns.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  atlas_btns.c - Atlas Wallmount Touchscreen ACPI Extras
   4  *
   5  *  Copyright (C) 2006 Jaya Kumar
   6  *  Based on Toshiba ACPI by John Belmonte and ASUS ACPI
   7  *  This work was sponsored by CIS(M) Sdn Bhd.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/input.h>
  15 #include <linux/types.h>
  16 #include <linux/acpi.h>
  17 #include <linux/uaccess.h>
  18
  19 #define ACPI_ATLAS_NAME         "Atlas ACPI"
  20 #define ACPI_ATLAS_CLASS        "Atlas"
  21
  22 static unsigned short atlas_keymap[16];
  23 static struct input_dev *input_dev;
  24
  25 /* button handling code */
  26 static acpi_status acpi_atlas_button_setup(acpi_handle region_handle,
  27                     u32 function, void *handler_context, void **return_context)
  28 {
  29         *return_context =
  30                 (function != ACPI_REGION_DEACTIVATE) ? handler_context : NULL;
  31
  32         return AE_OK;
  33 }
  34
  35 static acpi_status acpi_atlas_button_handler(u32 function,
  36                       acpi_physical_address address,
  37                       u32 bit_width, u64 *value,
  38                       void *handler_context, void *region_context)
  39 {
  40         acpi_status status;
  41
  42         if (function == ACPI_WRITE) {
  43                 int code = address & 0x0f;
  44                 int key_down = !(address & 0x10);
  45
  46                 input_event(input_dev, EV_MSC, MSC_SCAN, code);
  47                 input_report_key(input_dev, atlas_keymap[code], key_down);
  48                 input_sync(input_dev);
  49
  50                 status = AE_OK;
  51         } else {
  52                 pr_warn("shrugged on unexpected function: function=%x,address=%lx,value=%x\n",
  53                         function, (unsigned long)address, (u32)*value);
  54                 status = AE_BAD_PARAMETER;
  55         }
  56
  57         return status;
  58 }
  59
  60 static int atlas_acpi_button_add(struct acpi_device *device)
  61 {
  62         acpi_status status;
  63         int i;
  64         int err;
  65
  66         input_dev = input_allocate_device();
  67         if (!input_dev) {
  68                 pr_err("unable to allocate input device\n");
  69                 return -ENOMEM;
  70         }
  71
  72         input_dev->name = "Atlas ACPI button driver";
  73         input_dev->phys = "ASIM0000/atlas/input0";
  74         input_dev->id.bustype = BUS_HOST;
  75         input_dev->keycode = atlas_keymap;
  76         input_dev->keycodesize = sizeof(unsigned short);
  77         input_dev->keycodemax = ARRAY_SIZE(atlas_keymap);
  78
  79         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
  80         __set_bit(EV_KEY, input_dev->evbit);
  81         for (i = 0; i < ARRAY_SIZE(atlas_keymap); i++) {
  82                 if (i < 9) {
  83                         atlas_keymap[i] = KEY_F1 + i;
  84                         __set_bit(KEY_F1 + i, input_dev->keybit);
  85                 } else
  86                         atlas_keymap[i] = KEY_RESERVED;
  87         }
  88
  89         err = input_register_device(input_dev);
  90         if (err) {
  91                 pr_err("couldn't register input device\n");
  92                 input_free_device(input_dev);
  93                 return err;
  94         }
  95
  96         /* hookup button handler */
  97         status = acpi_install_address_space_handler(device->handle,
  98                                 0x81, &acpi_atlas_button_handler,
  99                                 &acpi_atlas_button_setup, device);
 100         if (ACPI_FAILURE(status)) {
 101                 pr_err("error installing addr spc handler\n");
 102                 input_unregister_device(input_dev);
 103                 err = -EINVAL;
 104         }
 105
 106         return err;
 107 }
 108
 109 static int atlas_acpi_button_remove(struct acpi_device *device)
 110 {
 111         acpi_status status;
 112
 113         status = acpi_remove_address_space_handler(device->handle,
 114                                 0x81, &acpi_atlas_button_handler);
 115         if (ACPI_FAILURE(status))
 116                 pr_err("error removing addr spc handler\n");
 117
 118         input_unregister_device(input_dev);
 119
 120         return 0;
 121 }
 122
 123 static const struct acpi_device_id atlas_device_ids[] = {
 124         {"ASIM0000", 0},
 125         {"", 0},
 126 };
 127 MODULE_DEVICE_TABLE(acpi, atlas_device_ids);
 128
 129 static struct acpi_driver atlas_acpi_driver = {
 130         .name   = ACPI_ATLAS_NAME,
 131         .class  = ACPI_ATLAS_CLASS,
 132         .owner  = THIS_MODULE,
 133         .ids    = atlas_device_ids,
 134         .ops    = {
 135                 .add    = atlas_acpi_button_add,
 136                 .remove = atlas_acpi_button_remove,
 137         },
 138 };
 139 module_acpi_driver(atlas_acpi_driver);
 140
 141 MODULE_AUTHOR("Jaya Kumar");
 142 MODULE_LICENSE("GPL");
 143 MODULE_DESCRIPTION("Atlas button driver");
 144