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
 31MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series");
 32MODULE_LICENSE("GPL");
 33
 34#define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4"
 35#define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8"
 36
 37static const char *dell_wmi_aio_guids[] = {
 38	EVENT_GUID1,
 39	EVENT_GUID2,
 40	NULL
 41};
 42
 43MODULE_ALIAS("wmi:"EVENT_GUID1);
 44MODULE_ALIAS("wmi:"EVENT_GUID2);
 45
 46static 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
 52static struct input_dev *dell_wmi_aio_input_dev;
 53
 54static 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
 91static 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
117err_free_keymap:
118	sparse_keymap_free(dell_wmi_aio_input_dev);
119err_free_dev:
120	input_free_device(dell_wmi_aio_input_dev);
121	return err;
122}
123
124static 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
135static 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
161static 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
171module_init(dell_wmi_aio_init);
172module_exit(dell_wmi_aio_exit);