2 * power/home/volume button support for
3 * Microsoft Surface Pro 3 tablet.
5 * Copyright (c) 2015 Intel Corporation.
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; version 2
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/input.h>
19 #include <linux/acpi.h>
20 #include <acpi/button.h>
22 #define SURFACE_BUTTON_HID "MSHW0028"
23 #define SURFACE_BUTTON_OBJ_NAME "VGBI"
24 #define SURFACE_BUTTON_DEVICE_NAME "Surface Pro 3 Buttons"
26 #define SURFACE_BUTTON_NOTIFY_PRESS_POWER 0xc6
27 #define SURFACE_BUTTON_NOTIFY_RELEASE_POWER 0xc7
29 #define SURFACE_BUTTON_NOTIFY_PRESS_HOME 0xc4
30 #define SURFACE_BUTTON_NOTIFY_RELEASE_HOME 0xc5
32 #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP 0xc0
33 #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1
35 #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN 0xc2
36 #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN 0xc3
38 ACPI_MODULE_NAME("surface pro 3 button");
40 MODULE_AUTHOR("Chen Yu");
41 MODULE_DESCRIPTION("Surface Pro3 Button Driver");
42 MODULE_LICENSE("GPL v2");
45 * Power button, Home button, Volume buttons support is supposed to
46 * be covered by drivers/input/misc/soc_button_array.c, which is implemented
47 * according to "Windows ACPI Design Guide for SoC Platforms".
48 * However surface pro3 seems not to obey the specs, instead it uses
49 * device VGBI(MSHW0028) for dispatching the events.
50 * We choose acpi_driver rather than platform_driver/i2c_driver because
51 * although VGBI has an i2c resource connected to i2c controller, it
52 * is not embedded in any i2c controller's scope, thus neither platform_device
53 * will be created, nor i2c_client will be enumerated, we have to use
56 static const struct acpi_device_id surface_button_device_ids
[] = {
57 {SURFACE_BUTTON_HID
, 0},
60 MODULE_DEVICE_TABLE(acpi
, surface_button_device_ids
);
62 struct surface_button
{
64 struct input_dev
*input
;
65 char phys
[32]; /* for input device */
70 static void surface_button_notify(struct acpi_device
*device
, u32 event
)
72 struct surface_button
*button
= acpi_driver_data(device
);
73 struct input_dev
*input
;
74 int key_code
= KEY_RESERVED
;
78 /* Power button press,release handle */
79 case SURFACE_BUTTON_NOTIFY_PRESS_POWER
:
82 case SURFACE_BUTTON_NOTIFY_RELEASE_POWER
:
85 /* Home button press,release handle */
86 case SURFACE_BUTTON_NOTIFY_PRESS_HOME
:
89 case SURFACE_BUTTON_NOTIFY_RELEASE_HOME
:
90 key_code
= KEY_LEFTMETA
;
92 /* Volume up button press,release handle */
93 case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP
:
96 case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP
:
97 key_code
= KEY_VOLUMEUP
;
99 /* Volume down button press,release handle */
100 case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN
:
103 case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN
:
104 key_code
= KEY_VOLUMEDOWN
;
107 dev_info_ratelimited(&device
->dev
,
108 "Unsupported event [0x%x]\n", event
);
111 input
= button
->input
;
112 if (KEY_RESERVED
== key_code
)
115 pm_wakeup_event(&device
->dev
, 0);
116 if (button
->suspended
)
118 input_report_key(input
, key_code
, pressed
?1:0);
122 #ifdef CONFIG_PM_SLEEP
123 static int surface_button_suspend(struct device
*dev
)
125 struct acpi_device
*device
= to_acpi_device(dev
);
126 struct surface_button
*button
= acpi_driver_data(device
);
128 button
->suspended
= true;
132 static int surface_button_resume(struct device
*dev
)
134 struct acpi_device
*device
= to_acpi_device(dev
);
135 struct surface_button
*button
= acpi_driver_data(device
);
137 button
->suspended
= false;
142 static int surface_button_add(struct acpi_device
*device
)
144 struct surface_button
*button
;
145 struct input_dev
*input
;
146 const char *hid
= acpi_device_hid(device
);
150 if (strncmp(acpi_device_bid(device
), SURFACE_BUTTON_OBJ_NAME
,
151 strlen(SURFACE_BUTTON_OBJ_NAME
)))
154 button
= kzalloc(sizeof(struct surface_button
), GFP_KERNEL
);
158 device
->driver_data
= button
;
159 button
->input
= input
= input_allocate_device();
162 goto err_free_button
;
165 name
= acpi_device_name(device
);
166 strcpy(name
, SURFACE_BUTTON_DEVICE_NAME
);
167 snprintf(button
->phys
, sizeof(button
->phys
), "%s/buttons", hid
);
170 input
->phys
= button
->phys
;
171 input
->id
.bustype
= BUS_HOST
;
172 input
->dev
.parent
= &device
->dev
;
173 input_set_capability(input
, EV_KEY
, KEY_POWER
);
174 input_set_capability(input
, EV_KEY
, KEY_LEFTMETA
);
175 input_set_capability(input
, EV_KEY
, KEY_VOLUMEUP
);
176 input_set_capability(input
, EV_KEY
, KEY_VOLUMEDOWN
);
178 error
= input_register_device(input
);
181 dev_info(&device
->dev
,
182 "%s [%s]\n", name
, acpi_device_bid(device
));
186 input_free_device(input
);
192 static int surface_button_remove(struct acpi_device
*device
)
194 struct surface_button
*button
= acpi_driver_data(device
);
196 input_unregister_device(button
->input
);
201 static SIMPLE_DEV_PM_OPS(surface_button_pm
,
202 surface_button_suspend
, surface_button_resume
);
204 static struct acpi_driver surface_button_driver
= {
205 .name
= "surface_pro3_button",
206 .class = "SurfacePro3",
207 .ids
= surface_button_device_ids
,
209 .add
= surface_button_add
,
210 .remove
= surface_button_remove
,
211 .notify
= surface_button_notify
,
213 .drv
.pm
= &surface_button_pm
,
216 module_acpi_driver(surface_button_driver
);