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 MSHW0040_DSM_REVISION 0x01 |
24 | #define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision |
25 | static const guid_t MSHW0040_DSM_UUID = |
26 | GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65, |
27 | 0x49, 0x80, 0x35); |
28 | |
29 | #define SURFACE_BUTTON_NOTIFY_TABLET_MODE 0xc8 |
30 | |
31 | #define SURFACE_BUTTON_NOTIFY_PRESS_POWER 0xc6 |
32 | #define SURFACE_BUTTON_NOTIFY_RELEASE_POWER 0xc7 |
33 | |
34 | #define SURFACE_BUTTON_NOTIFY_PRESS_HOME 0xc4 |
35 | #define SURFACE_BUTTON_NOTIFY_RELEASE_HOME 0xc5 |
36 | |
37 | #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP 0xc0 |
38 | #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP 0xc1 |
39 | |
40 | #define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN 0xc2 |
41 | #define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN 0xc3 |
42 | |
43 | MODULE_AUTHOR("Chen Yu" ); |
44 | MODULE_DESCRIPTION("Surface Pro3 Button Driver" ); |
45 | MODULE_LICENSE("GPL v2" ); |
46 | |
47 | /* |
48 | * Power button, Home button, Volume buttons support is supposed to |
49 | * be covered by drivers/input/misc/soc_button_array.c, which is implemented |
50 | * according to "Windows ACPI Design Guide for SoC Platforms". |
51 | * However surface pro3 seems not to obey the specs, instead it uses |
52 | * device VGBI(MSHW0028) for dispatching the events. |
53 | * We choose acpi_driver rather than platform_driver/i2c_driver because |
54 | * although VGBI has an i2c resource connected to i2c controller, it |
55 | * is not embedded in any i2c controller's scope, thus neither platform_device |
56 | * will be created, nor i2c_client will be enumerated, we have to use |
57 | * acpi_driver. |
58 | */ |
59 | static const struct acpi_device_id surface_button_device_ids[] = { |
60 | {SURFACE_PRO3_BUTTON_HID, 0}, |
61 | {SURFACE_PRO4_BUTTON_HID, 0}, |
62 | {"" , 0}, |
63 | }; |
64 | MODULE_DEVICE_TABLE(acpi, surface_button_device_ids); |
65 | |
66 | struct surface_button { |
67 | unsigned int type; |
68 | struct input_dev *input; |
69 | char phys[32]; /* for input device */ |
70 | unsigned long pushed; |
71 | bool suspended; |
72 | }; |
73 | |
74 | static void surface_button_notify(struct acpi_device *device, u32 event) |
75 | { |
76 | struct surface_button *button = acpi_driver_data(d: device); |
77 | struct input_dev *input; |
78 | int key_code = KEY_RESERVED; |
79 | bool pressed = false; |
80 | |
81 | switch (event) { |
82 | /* Power button press,release handle */ |
83 | case SURFACE_BUTTON_NOTIFY_PRESS_POWER: |
84 | pressed = true; |
85 | fallthrough; |
86 | case SURFACE_BUTTON_NOTIFY_RELEASE_POWER: |
87 | key_code = KEY_POWER; |
88 | break; |
89 | /* Home button press,release handle */ |
90 | case SURFACE_BUTTON_NOTIFY_PRESS_HOME: |
91 | pressed = true; |
92 | fallthrough; |
93 | case SURFACE_BUTTON_NOTIFY_RELEASE_HOME: |
94 | key_code = KEY_LEFTMETA; |
95 | break; |
96 | /* Volume up button press,release handle */ |
97 | case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP: |
98 | pressed = true; |
99 | fallthrough; |
100 | case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP: |
101 | key_code = KEY_VOLUMEUP; |
102 | break; |
103 | /* Volume down button press,release handle */ |
104 | case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN: |
105 | pressed = true; |
106 | fallthrough; |
107 | case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN: |
108 | key_code = KEY_VOLUMEDOWN; |
109 | break; |
110 | case SURFACE_BUTTON_NOTIFY_TABLET_MODE: |
111 | dev_warn_once(&device->dev, "Tablet mode is not supported\n" ); |
112 | break; |
113 | default: |
114 | dev_info_ratelimited(&device->dev, |
115 | "Unsupported event [0x%x]\n" , event); |
116 | break; |
117 | } |
118 | input = button->input; |
119 | if (key_code == KEY_RESERVED) |
120 | return; |
121 | if (pressed) |
122 | pm_wakeup_dev_event(dev: &device->dev, msec: 0, hard: button->suspended); |
123 | if (button->suspended) |
124 | return; |
125 | input_report_key(dev: input, code: key_code, value: pressed?1:0); |
126 | input_sync(dev: input); |
127 | } |
128 | |
129 | #ifdef CONFIG_PM_SLEEP |
130 | static int surface_button_suspend(struct device *dev) |
131 | { |
132 | struct acpi_device *device = to_acpi_device(dev); |
133 | struct surface_button *button = acpi_driver_data(d: device); |
134 | |
135 | button->suspended = true; |
136 | return 0; |
137 | } |
138 | |
139 | static int surface_button_resume(struct device *dev) |
140 | { |
141 | struct acpi_device *device = to_acpi_device(dev); |
142 | struct surface_button *button = acpi_driver_data(d: device); |
143 | |
144 | button->suspended = false; |
145 | return 0; |
146 | } |
147 | #endif |
148 | |
149 | /* |
150 | * Surface Pro 4 and Surface Book 2 / Surface Pro 2017 use the same device |
151 | * ID (MSHW0040) for the power/volume buttons. Make sure this is the right |
152 | * device by checking for the _DSM method and OEM Platform Revision. |
153 | * |
154 | * Returns true if the driver should bind to this device, i.e. the device is |
155 | * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1. |
156 | */ |
157 | static bool surface_button_check_MSHW0040(struct acpi_device *dev) |
158 | { |
159 | acpi_handle handle = dev->handle; |
160 | union acpi_object *result; |
161 | u64 oem_platform_rev = 0; // valid revisions are nonzero |
162 | |
163 | // get OEM platform revision |
164 | result = acpi_evaluate_dsm_typed(handle, guid: &MSHW0040_DSM_UUID, |
165 | MSHW0040_DSM_REVISION, |
166 | MSHW0040_DSM_GET_OMPR, |
167 | NULL, ACPI_TYPE_INTEGER); |
168 | |
169 | /* |
170 | * If evaluating the _DSM fails, the method is not present. This means |
171 | * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we |
172 | * should use this driver. We use revision 0 indicating it is |
173 | * unavailable. |
174 | */ |
175 | |
176 | if (result) { |
177 | oem_platform_rev = result->integer.value; |
178 | ACPI_FREE(result); |
179 | } |
180 | |
181 | dev_dbg(&dev->dev, "OEM Platform Revision %llu\n" , oem_platform_rev); |
182 | |
183 | return oem_platform_rev == 0; |
184 | } |
185 | |
186 | |
187 | static int surface_button_add(struct acpi_device *device) |
188 | { |
189 | struct surface_button *button; |
190 | struct input_dev *input; |
191 | const char *hid = acpi_device_hid(device); |
192 | char *name; |
193 | int error; |
194 | |
195 | if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME, |
196 | strlen(SURFACE_BUTTON_OBJ_NAME))) |
197 | return -ENODEV; |
198 | |
199 | if (!surface_button_check_MSHW0040(dev: device)) |
200 | return -ENODEV; |
201 | |
202 | button = kzalloc(size: sizeof(struct surface_button), GFP_KERNEL); |
203 | if (!button) |
204 | return -ENOMEM; |
205 | |
206 | device->driver_data = button; |
207 | button->input = input = input_allocate_device(); |
208 | if (!input) { |
209 | error = -ENOMEM; |
210 | goto err_free_button; |
211 | } |
212 | |
213 | name = acpi_device_name(device); |
214 | strcpy(p: name, SURFACE_BUTTON_DEVICE_NAME); |
215 | snprintf(buf: button->phys, size: sizeof(button->phys), fmt: "%s/buttons" , hid); |
216 | |
217 | input->name = name; |
218 | input->phys = button->phys; |
219 | input->id.bustype = BUS_HOST; |
220 | input->dev.parent = &device->dev; |
221 | input_set_capability(dev: input, EV_KEY, KEY_POWER); |
222 | input_set_capability(dev: input, EV_KEY, KEY_LEFTMETA); |
223 | input_set_capability(dev: input, EV_KEY, KEY_VOLUMEUP); |
224 | input_set_capability(dev: input, EV_KEY, KEY_VOLUMEDOWN); |
225 | |
226 | error = input_register_device(input); |
227 | if (error) |
228 | goto err_free_input; |
229 | |
230 | device_init_wakeup(dev: &device->dev, enable: true); |
231 | dev_info(&device->dev, |
232 | "%s [%s]\n" , name, acpi_device_bid(device)); |
233 | return 0; |
234 | |
235 | err_free_input: |
236 | input_free_device(dev: input); |
237 | err_free_button: |
238 | kfree(objp: button); |
239 | return error; |
240 | } |
241 | |
242 | static void surface_button_remove(struct acpi_device *device) |
243 | { |
244 | struct surface_button *button = acpi_driver_data(d: device); |
245 | |
246 | input_unregister_device(button->input); |
247 | kfree(objp: button); |
248 | } |
249 | |
250 | static SIMPLE_DEV_PM_OPS(surface_button_pm, |
251 | surface_button_suspend, surface_button_resume); |
252 | |
253 | static struct acpi_driver surface_button_driver = { |
254 | .name = "surface_pro3_button" , |
255 | .class = "SurfacePro3" , |
256 | .ids = surface_button_device_ids, |
257 | .ops = { |
258 | .add = surface_button_add, |
259 | .remove = surface_button_remove, |
260 | .notify = surface_button_notify, |
261 | }, |
262 | .drv.pm = &surface_button_pm, |
263 | }; |
264 | |
265 | module_acpi_driver(surface_button_driver); |
266 | |