drivers/platform/x86/dell-wmi-aio.c

   1 /*
   2  *  WMI hotkeys support for Dell All-In-One series
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, write to the Free Software
  16  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/types.h>
  25 #include <linux/input.h>
  26 #include <linux/input/sparse-keymap.h>
  27 #include <acpi/acpi_drivers.h>
  28 #include <linux/acpi.h>
  29 #include <linux/string.h>
  30
  31 MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series");
  32 MODULE_LICENSE("GPL");
  33
  34 #define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4"
  35 #define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8"
  36
  37 static const char *dell_wmi_aio_guids[] = {
  38         EVENT_GUID1,
  39         EVENT_GUID2,
  40         NULL
  41 };
  42
  43 MODULE_ALIAS("wmi:"EVENT_GUID1);
  44 MODULE_ALIAS("wmi:"EVENT_GUID2);
  45
  46 static const struct key_entry dell_wmi_aio_keymap[] = {
  47         { KE_KEY, 0xc0, { KEY_VOLUMEUP } },
  48         { KE_KEY, 0xc1, { KEY_VOLUMEDOWN } },
  49         { KE_END, 0 }
  50 };
  51
  52 static struct input_dev *dell_wmi_aio_input_dev;
  53
  54 static void dell_wmi_aio_notify(u32 value, void *context)
  55 {
  56         struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
  57         union acpi_object *obj;
  58         acpi_status status;
  59
  60         status = wmi_get_event_data(value, &response);
  61         if (status != AE_OK) {
  62                 pr_info("bad event status 0x%x\n", status);
  63                 return;
  64         }
  65
  66         obj = (union acpi_object *)response.pointer;
  67         if (obj) {
  68                 unsigned int scancode;
  69
  70                 switch (obj->type) {
  71                 case ACPI_TYPE_INTEGER:
  72                         /* Most All-In-One correctly return integer scancode */
  73                         scancode = obj->integer.value;
  74                         sparse_keymap_report_event(dell_wmi_aio_input_dev,
  75                                 scancode, 1, true);
  76                         break;
  77                 case ACPI_TYPE_BUFFER:
  78                         /* Broken machines return the scancode in a buffer */
  79                         if (obj->buffer.pointer && obj->buffer.length > 0) {
  80                                 scancode = obj->buffer.pointer[0];
  81                                 sparse_keymap_report_event(
  82                                         dell_wmi_aio_input_dev,
  83                                         scancode, 1, true);
  84                         }
  85                         break;
  86                 }
  87         }
  88         kfree(obj);
  89 }
  90
  91 static int __init dell_wmi_aio_input_setup(void)
  92 {
  93         int err;
  94
  95         dell_wmi_aio_input_dev = input_allocate_device();
  96
  97         if (!dell_wmi_aio_input_dev)
  98                 return -ENOMEM;
  99
 100         dell_wmi_aio_input_dev->name = "Dell AIO WMI hotkeys";
 101         dell_wmi_aio_input_dev->phys = "wmi/input0";
 102         dell_wmi_aio_input_dev->id.bustype = BUS_HOST;
 103
 104         err = sparse_keymap_setup(dell_wmi_aio_input_dev,
 105                         dell_wmi_aio_keymap, NULL);
 106         if (err) {
 107                 pr_err("Unable to setup input device keymap\n");
 108                 goto err_free_dev;
 109         }
 110         err = input_register_device(dell_wmi_aio_input_dev);
 111         if (err) {
 112                 pr_info("Unable to register input device\n");
 113                 goto err_free_keymap;
 114         }
 115         return 0;
 116
 117 err_free_keymap:
 118         sparse_keymap_free(dell_wmi_aio_input_dev);
 119 err_free_dev:
 120         input_free_device(dell_wmi_aio_input_dev);
 121         return err;
 122 }
 123
 124 static const char *dell_wmi_aio_find(void)
 125 {
 126         int i;
 127
 128         for (i = 0; dell_wmi_aio_guids[i] != NULL; i++)
 129                 if (wmi_has_guid(dell_wmi_aio_guids[i]))
 130                         return dell_wmi_aio_guids[i];
 131
 132         return NULL;
 133 }
 134
 135 static int __init dell_wmi_aio_init(void)
 136 {
 137         int err;
 138         const char *guid;
 139
 140         guid = dell_wmi_aio_find();
 141         if (!guid) {
 142                 pr_warn("No known WMI GUID found\n");
 143                 return -ENXIO;
 144         }
 145
 146         err = dell_wmi_aio_input_setup();
 147         if (err)
 148                 return err;
 149
 150         err = wmi_install_notify_handler(guid, dell_wmi_aio_notify, NULL);
 151         if (err) {
 152                 pr_err("Unable to register notify handler - %d\n", err);
 153                 sparse_keymap_free(dell_wmi_aio_input_dev);
 154                 input_unregister_device(dell_wmi_aio_input_dev);
 155                 return err;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static void __exit dell_wmi_aio_exit(void)
 162 {
 163         const char *guid;
 164
 165         guid = dell_wmi_aio_find();
 166         wmi_remove_notify_handler(guid);
 167         sparse_keymap_free(dell_wmi_aio_input_dev);
 168         input_unregister_device(dell_wmi_aio_input_dev);
 169 }
 170
 171 module_init(dell_wmi_aio_init);
 172 module_exit(dell_wmi_aio_exit);