Linux 5.3-rc4
[sfrench/cifs-2.6.git] / drivers / platform / x86 / surfacepro3_button.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * power/home/volume button support for
4  * Microsoft Surface Pro 3/4 tablet.
5  *
6  * Copyright (c) 2015 Intel Corporation.
7  * All rights reserved.
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/input.h>
15 #include <linux/acpi.h>
16 #include <acpi/button.h>
17
18 #define SURFACE_PRO3_BUTTON_HID         "MSHW0028"
19 #define SURFACE_PRO4_BUTTON_HID         "MSHW0040"
20 #define SURFACE_BUTTON_OBJ_NAME         "VGBI"
21 #define SURFACE_BUTTON_DEVICE_NAME      "Surface Pro 3/4 Buttons"
22
23 #define SURFACE_BUTTON_NOTIFY_TABLET_MODE       0xc8
24
25 #define SURFACE_BUTTON_NOTIFY_PRESS_POWER       0xc6
26 #define SURFACE_BUTTON_NOTIFY_RELEASE_POWER     0xc7
27
28 #define SURFACE_BUTTON_NOTIFY_PRESS_HOME        0xc4
29 #define SURFACE_BUTTON_NOTIFY_RELEASE_HOME      0xc5
30
31 #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP   0xc0
32 #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1
33
34 #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN         0xc2
35 #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN       0xc3
36
37 ACPI_MODULE_NAME("surface pro 3 button");
38
39 MODULE_AUTHOR("Chen Yu");
40 MODULE_DESCRIPTION("Surface Pro3 Button Driver");
41 MODULE_LICENSE("GPL v2");
42
43 /*
44  * Power button, Home button, Volume buttons support is supposed to
45  * be covered by drivers/input/misc/soc_button_array.c, which is implemented
46  * according to "Windows ACPI Design Guide for SoC Platforms".
47  * However surface pro3 seems not to obey the specs, instead it uses
48  * device VGBI(MSHW0028) for dispatching the events.
49  * We choose acpi_driver rather than platform_driver/i2c_driver because
50  * although VGBI has an i2c resource connected to i2c controller, it
51  * is not embedded in any i2c controller's scope, thus neither platform_device
52  * will be created, nor i2c_client will be enumerated, we have to use
53  * acpi_driver.
54  */
55 static const struct acpi_device_id surface_button_device_ids[] = {
56         {SURFACE_PRO3_BUTTON_HID,    0},
57         {SURFACE_PRO4_BUTTON_HID,    0},
58         {"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, surface_button_device_ids);
61
62 struct surface_button {
63         unsigned int type;
64         struct input_dev *input;
65         char phys[32];                  /* for input device */
66         unsigned long pushed;
67         bool suspended;
68 };
69
70 static void surface_button_notify(struct acpi_device *device, u32 event)
71 {
72         struct surface_button *button = acpi_driver_data(device);
73         struct input_dev *input;
74         int key_code = KEY_RESERVED;
75         bool pressed = false;
76
77         switch (event) {
78         /* Power button press,release handle */
79         case SURFACE_BUTTON_NOTIFY_PRESS_POWER:
80                 pressed = true;
81                 /*fall through*/
82         case SURFACE_BUTTON_NOTIFY_RELEASE_POWER:
83                 key_code = KEY_POWER;
84                 break;
85         /* Home button press,release handle */
86         case SURFACE_BUTTON_NOTIFY_PRESS_HOME:
87                 pressed = true;
88                 /*fall through*/
89         case SURFACE_BUTTON_NOTIFY_RELEASE_HOME:
90                 key_code = KEY_LEFTMETA;
91                 break;
92         /* Volume up button press,release handle */
93         case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP:
94                 pressed = true;
95                 /*fall through*/
96         case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP:
97                 key_code = KEY_VOLUMEUP;
98                 break;
99         /* Volume down button press,release handle */
100         case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN:
101                 pressed = true;
102                 /*fall through*/
103         case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN:
104                 key_code = KEY_VOLUMEDOWN;
105                 break;
106         case SURFACE_BUTTON_NOTIFY_TABLET_MODE:
107                 dev_warn_once(&device->dev, "Tablet mode is not supported\n");
108                 break;
109         default:
110                 dev_info_ratelimited(&device->dev,
111                                      "Unsupported event [0x%x]\n", event);
112                 break;
113         }
114         input = button->input;
115         if (key_code == KEY_RESERVED)
116                 return;
117         if (pressed)
118                 pm_wakeup_dev_event(&device->dev, 0, button->suspended);
119         if (button->suspended)
120                 return;
121         input_report_key(input, key_code, pressed?1:0);
122         input_sync(input);
123 }
124
125 #ifdef CONFIG_PM_SLEEP
126 static int surface_button_suspend(struct device *dev)
127 {
128         struct acpi_device *device = to_acpi_device(dev);
129         struct surface_button *button = acpi_driver_data(device);
130
131         button->suspended = true;
132         return 0;
133 }
134
135 static int surface_button_resume(struct device *dev)
136 {
137         struct acpi_device *device = to_acpi_device(dev);
138         struct surface_button *button = acpi_driver_data(device);
139
140         button->suspended = false;
141         return 0;
142 }
143 #endif
144
145 static int surface_button_add(struct acpi_device *device)
146 {
147         struct surface_button *button;
148         struct input_dev *input;
149         const char *hid = acpi_device_hid(device);
150         char *name;
151         int error;
152
153         if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME,
154             strlen(SURFACE_BUTTON_OBJ_NAME)))
155                 return -ENODEV;
156
157         button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
158         if (!button)
159                 return -ENOMEM;
160
161         device->driver_data = button;
162         button->input = input = input_allocate_device();
163         if (!input) {
164                 error = -ENOMEM;
165                 goto err_free_button;
166         }
167
168         name = acpi_device_name(device);
169         strcpy(name, SURFACE_BUTTON_DEVICE_NAME);
170         snprintf(button->phys, sizeof(button->phys), "%s/buttons", hid);
171
172         input->name = name;
173         input->phys = button->phys;
174         input->id.bustype = BUS_HOST;
175         input->dev.parent = &device->dev;
176         input_set_capability(input, EV_KEY, KEY_POWER);
177         input_set_capability(input, EV_KEY, KEY_LEFTMETA);
178         input_set_capability(input, EV_KEY, KEY_VOLUMEUP);
179         input_set_capability(input, EV_KEY, KEY_VOLUMEDOWN);
180
181         error = input_register_device(input);
182         if (error)
183                 goto err_free_input;
184
185         device_init_wakeup(&device->dev, true);
186         dev_info(&device->dev,
187                         "%s [%s]\n", name, acpi_device_bid(device));
188         return 0;
189
190  err_free_input:
191         input_free_device(input);
192  err_free_button:
193         kfree(button);
194         return error;
195 }
196
197 static int surface_button_remove(struct acpi_device *device)
198 {
199         struct surface_button *button = acpi_driver_data(device);
200
201         input_unregister_device(button->input);
202         kfree(button);
203         return 0;
204 }
205
206 static SIMPLE_DEV_PM_OPS(surface_button_pm,
207                 surface_button_suspend, surface_button_resume);
208
209 static struct acpi_driver surface_button_driver = {
210         .name = "surface_pro3_button",
211         .class = "SurfacePro3",
212         .ids = surface_button_device_ids,
213         .ops = {
214                 .add = surface_button_add,
215                 .remove = surface_button_remove,
216                 .notify = surface_button_notify,
217         },
218         .drv.pm = &surface_button_pm,
219 };
220
221 module_acpi_driver(surface_button_driver);