1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Huawei WMI hotkeys
4  *
5  *  Copyright (C) 2018	      Ayman Bagabas <ayman.bagabas@gmail.com>
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/input.h>
10 #include <linux/input/sparse-keymap.h>
11 #include <linux/leds.h>
12 #include <linux/module.h>
13 #include <linux/wmi.h>
14 
15 /*
16  * Huawei WMI GUIDs
17  */
18 #define WMI0_EVENT_GUID "59142400-C6A3-40fa-BADB-8A2652834100"
19 #define AMW0_EVENT_GUID "ABBC0F5C-8EA1-11D1-A000-C90629100000"
20 
21 #define WMI0_EXPENSIVE_GUID "39142400-C6A3-40fa-BADB-8A2652834100"
22 
23 struct huawei_wmi_priv {
24 	struct input_dev *idev;
25 	struct led_classdev cdev;
26 	acpi_handle handle;
27 	char *acpi_method;
28 };
29 
30 static const struct key_entry huawei_wmi_keymap[] = {
31 	{ KE_KEY,    0x281, { KEY_BRIGHTNESSDOWN } },
32 	{ KE_KEY,    0x282, { KEY_BRIGHTNESSUP } },
33 	{ KE_KEY,    0x284, { KEY_MUTE } },
34 	{ KE_KEY,    0x285, { KEY_VOLUMEDOWN } },
35 	{ KE_KEY,    0x286, { KEY_VOLUMEUP } },
36 	{ KE_KEY,    0x287, { KEY_MICMUTE } },
37 	{ KE_KEY,    0x289, { KEY_WLAN } },
38 	// Huawei |M| key
39 	{ KE_KEY,    0x28a, { KEY_CONFIG } },
40 	// Keyboard backlight
41 	{ KE_IGNORE, 0x293, { KEY_KBDILLUMTOGGLE } },
42 	{ KE_IGNORE, 0x294, { KEY_KBDILLUMUP } },
43 	{ KE_IGNORE, 0x295, { KEY_KBDILLUMUP } },
44 	{ KE_END,	 0 }
45 };
46 
47 static int huawei_wmi_micmute_led_set(struct led_classdev *led_cdev,
48 		enum led_brightness brightness)
49 {
50 	struct huawei_wmi_priv *priv = dev_get_drvdata(led_cdev->dev->parent);
51 	acpi_status status;
52 	union acpi_object args[3];
53 	struct acpi_object_list arg_list = {
54 		.pointer = args,
55 		.count = ARRAY_SIZE(args),
56 	};
57 
58 	args[0].type = args[1].type = args[2].type = ACPI_TYPE_INTEGER;
59 	args[1].integer.value = 0x04;
60 
61 	if (strcmp(priv->acpi_method, "SPIN") == 0) {
62 		args[0].integer.value = 0;
63 		args[2].integer.value = brightness ? 1 : 0;
64 	} else if (strcmp(priv->acpi_method, "WPIN") == 0) {
65 		args[0].integer.value = 1;
66 		args[2].integer.value = brightness ? 0 : 1;
67 	} else {
68 		return -EINVAL;
69 	}
70 
71 	status = acpi_evaluate_object(priv->handle, priv->acpi_method, &arg_list, NULL);
72 	if (ACPI_FAILURE(status))
73 		return -ENXIO;
74 
75 	return 0;
76 }
77 
78 static int huawei_wmi_leds_setup(struct wmi_device *wdev)
79 {
80 	struct huawei_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
81 
82 	priv->handle = ec_get_handle();
83 	if (!priv->handle)
84 		return 0;
85 
86 	if (acpi_has_method(priv->handle, "SPIN"))
87 		priv->acpi_method = "SPIN";
88 	else if (acpi_has_method(priv->handle, "WPIN"))
89 		priv->acpi_method = "WPIN";
90 	else
91 		return 0;
92 
93 	priv->cdev.name = "platform::micmute";
94 	priv->cdev.max_brightness = 1;
95 	priv->cdev.brightness_set_blocking = huawei_wmi_micmute_led_set;
96 	priv->cdev.default_trigger = "audio-micmute";
97 	priv->cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
98 	priv->cdev.dev = &wdev->dev;
99 	priv->cdev.flags = LED_CORE_SUSPENDRESUME;
100 
101 	return devm_led_classdev_register(&wdev->dev, &priv->cdev);
102 }
103 
104 static void huawei_wmi_process_key(struct wmi_device *wdev, int code)
105 {
106 	struct huawei_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
107 	const struct key_entry *key;
108 
109 	/*
110 	 * WMI0 uses code 0x80 to indicate a hotkey event.
111 	 * The actual key is fetched from the method WQ00
112 	 * using WMI0_EXPENSIVE_GUID.
113 	 */
114 	if (code == 0x80) {
115 		struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
116 		union acpi_object *obj;
117 		acpi_status status;
118 
119 		status = wmi_query_block(WMI0_EXPENSIVE_GUID, 0, &response);
120 		if (ACPI_FAILURE(status))
121 			return;
122 
123 		obj = (union acpi_object *)response.pointer;
124 		if (obj && obj->type == ACPI_TYPE_INTEGER)
125 			code = obj->integer.value;
126 
127 		kfree(response.pointer);
128 	}
129 
130 	key = sparse_keymap_entry_from_scancode(priv->idev, code);
131 	if (!key) {
132 		dev_info(&wdev->dev, "Unknown key pressed, code: 0x%04x\n", code);
133 		return;
134 	}
135 
136 	sparse_keymap_report_entry(priv->idev, key, 1, true);
137 }
138 
139 static void huawei_wmi_notify(struct wmi_device *wdev,
140 		union acpi_object *obj)
141 {
142 	if (obj->type == ACPI_TYPE_INTEGER)
143 		huawei_wmi_process_key(wdev, obj->integer.value);
144 	else
145 		dev_info(&wdev->dev, "Bad response type %d\n", obj->type);
146 }
147 
148 static int huawei_wmi_input_setup(struct wmi_device *wdev)
149 {
150 	struct huawei_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
151 	int err;
152 
153 	priv->idev = devm_input_allocate_device(&wdev->dev);
154 	if (!priv->idev)
155 		return -ENOMEM;
156 
157 	priv->idev->name = "Huawei WMI hotkeys";
158 	priv->idev->phys = "wmi/input0";
159 	priv->idev->id.bustype = BUS_HOST;
160 	priv->idev->dev.parent = &wdev->dev;
161 
162 	err = sparse_keymap_setup(priv->idev, huawei_wmi_keymap, NULL);
163 	if (err)
164 		return err;
165 
166 	return input_register_device(priv->idev);
167 }
168 
169 static int huawei_wmi_probe(struct wmi_device *wdev)
170 {
171 	struct huawei_wmi_priv *priv;
172 	int err;
173 
174 	priv = devm_kzalloc(&wdev->dev, sizeof(struct huawei_wmi_priv), GFP_KERNEL);
175 	if (!priv)
176 		return -ENOMEM;
177 
178 	dev_set_drvdata(&wdev->dev, priv);
179 
180 	err = huawei_wmi_input_setup(wdev);
181 	if (err)
182 		return err;
183 
184 	return huawei_wmi_leds_setup(wdev);
185 }
186 
187 static const struct wmi_device_id huawei_wmi_id_table[] = {
188 	{ .guid_string = WMI0_EVENT_GUID },
189 	{ .guid_string = AMW0_EVENT_GUID },
190 	{  }
191 };
192 
193 static struct wmi_driver huawei_wmi_driver = {
194 	.driver = {
195 		.name = "huawei-wmi",
196 	},
197 	.id_table = huawei_wmi_id_table,
198 	.probe = huawei_wmi_probe,
199 	.notify = huawei_wmi_notify,
200 };
201 
202 module_wmi_driver(huawei_wmi_driver);
203 
204 MODULE_ALIAS("wmi:"WMI0_EVENT_GUID);
205 MODULE_ALIAS("wmi:"AMW0_EVENT_GUID);
206 MODULE_AUTHOR("Ayman Bagabas <ayman.bagabas@gmail.com>");
207 MODULE_DESCRIPTION("Huawei WMI hotkeys");
208 MODULE_LICENSE("GPL v2");
209