1 // SPDX-License-Identifier: GPL-2.0
2 /* WMI driver for Lenovo Yoga Book YB1-X90* / -X91* tablets */
3 
4 #include <linux/acpi.h>
5 #include <linux/devm-helpers.h>
6 #include <linux/gpio/consumer.h>
7 #include <linux/gpio/machine.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/leds.h>
11 #include <linux/wmi.h>
12 #include <linux/workqueue.h>
13 
14 #define YB_MBTN_EVENT_GUID	"243FEC1D-1963-41C1-8100-06A9D82A94B4"
15 #define YB_MBTN_METHOD_GUID	"742B0CA1-0B20-404B-9CAA-AEFCABF30CE0"
16 
17 #define YB_PAD_ENABLE	1
18 #define YB_PAD_DISABLE	2
19 #define YB_LIGHTUP_BTN	3
20 
21 #define YB_KBD_BL_DEFAULT 128
22 
23 /* flags */
24 enum {
25 	YB_KBD_IS_ON,
26 	YB_DIGITIZER_IS_ON,
27 	YB_DIGITIZER_MODE,
28 	YB_TABLET_MODE,
29 	YB_SUSPENDED,
30 };
31 
32 struct yogabook_wmi {
33 	struct wmi_device *wdev;
34 	struct acpi_device *kbd_adev;
35 	struct acpi_device *dig_adev;
36 	struct device *kbd_dev;
37 	struct device *dig_dev;
38 	struct gpio_desc *backside_hall_gpio;
39 	int backside_hall_irq;
40 	struct work_struct work;
41 	struct led_classdev kbd_bl_led;
42 	unsigned long flags;
43 	uint8_t brightness;
44 };
45 
yogabook_wmi_do_action(struct wmi_device * wdev,int action)46 static int yogabook_wmi_do_action(struct wmi_device *wdev, int action)
47 {
48 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
49 	struct acpi_buffer input;
50 	acpi_status status;
51 	u32 dummy_arg = 0;
52 
53 	dev_dbg(&wdev->dev, "Do action: %d\n", action);
54 
55 	input.pointer = &dummy_arg;
56 	input.length = sizeof(dummy_arg);
57 
58 	status = wmi_evaluate_method(YB_MBTN_METHOD_GUID, 0, action, &input,
59 				     &output);
60 	if (ACPI_FAILURE(status)) {
61 		dev_err(&wdev->dev, "Calling WMI method failure: 0x%x\n",
62 			status);
63 		return status;
64 	}
65 
66 	kfree(output.pointer);
67 
68 	return 0;
69 }
70 
71 /*
72  * To control keyboard backlight, call the method KBLC() of the TCS1 ACPI
73  * device (Goodix touchpad acts as virtual sensor keyboard).
74  */
yogabook_wmi_set_kbd_backlight(struct wmi_device * wdev,uint8_t level)75 static int yogabook_wmi_set_kbd_backlight(struct wmi_device *wdev,
76 					  uint8_t level)
77 {
78 	struct yogabook_wmi *data = dev_get_drvdata(&wdev->dev);
79 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
80 	struct acpi_object_list input;
81 	union acpi_object param;
82 	acpi_status status;
83 
84 	if (data->kbd_adev->power.state != ACPI_STATE_D0) {
85 		dev_warn(&wdev->dev, "keyboard touchscreen not in D0, cannot set brightness\n");
86 		return -ENXIO;
87 	}
88 
89 	dev_dbg(&wdev->dev, "Set KBLC level to %u\n", level);
90 
91 	input.count = 1;
92 	input.pointer = &param;
93 
94 	param.type = ACPI_TYPE_INTEGER;
95 	param.integer.value = 255 - level;
96 
97 	status = acpi_evaluate_object(acpi_device_handle(data->kbd_adev), "KBLC",
98 				      &input, &output);
99 	if (ACPI_FAILURE(status)) {
100 		dev_err(&wdev->dev, "Failed to call KBLC method: 0x%x\n", status);
101 		return status;
102 	}
103 
104 	kfree(output.pointer);
105 	return 0;
106 }
107 
yogabook_wmi_work(struct work_struct * work)108 static void yogabook_wmi_work(struct work_struct *work)
109 {
110 	struct yogabook_wmi *data = container_of(work, struct yogabook_wmi, work);
111 	struct device *dev = &data->wdev->dev;
112 	bool kbd_on, digitizer_on;
113 	int r;
114 
115 	if (test_bit(YB_SUSPENDED, &data->flags))
116 		return;
117 
118 	if (test_bit(YB_TABLET_MODE, &data->flags)) {
119 		kbd_on = false;
120 		digitizer_on = false;
121 	} else if (test_bit(YB_DIGITIZER_MODE, &data->flags)) {
122 		digitizer_on = true;
123 		kbd_on = false;
124 	} else {
125 		kbd_on = true;
126 		digitizer_on = false;
127 	}
128 
129 	if (!kbd_on && test_bit(YB_KBD_IS_ON, &data->flags)) {
130 		/*
131 		 * Must be done before releasing the keyboard touchscreen driver,
132 		 * so that the keyboard touchscreen dev is still in D0.
133 		 */
134 		yogabook_wmi_set_kbd_backlight(data->wdev, 0);
135 		device_release_driver(data->kbd_dev);
136 		clear_bit(YB_KBD_IS_ON, &data->flags);
137 	}
138 
139 	if (!digitizer_on && test_bit(YB_DIGITIZER_IS_ON, &data->flags)) {
140 		yogabook_wmi_do_action(data->wdev, YB_PAD_DISABLE);
141 		device_release_driver(data->dig_dev);
142 		clear_bit(YB_DIGITIZER_IS_ON, &data->flags);
143 	}
144 
145 	if (kbd_on && !test_bit(YB_KBD_IS_ON, &data->flags)) {
146 		r = device_reprobe(data->kbd_dev);
147 		if (r)
148 			dev_warn(dev, "Reprobe of keyboard touchscreen failed: %d\n", r);
149 
150 		yogabook_wmi_set_kbd_backlight(data->wdev, data->brightness);
151 		set_bit(YB_KBD_IS_ON, &data->flags);
152 	}
153 
154 	if (digitizer_on && !test_bit(YB_DIGITIZER_IS_ON, &data->flags)) {
155 		r = device_reprobe(data->dig_dev);
156 		if (r)
157 			dev_warn(dev, "Reprobe of digitizer failed: %d\n", r);
158 
159 		yogabook_wmi_do_action(data->wdev, YB_PAD_ENABLE);
160 		set_bit(YB_DIGITIZER_IS_ON, &data->flags);
161 	}
162 }
163 
yogabook_wmi_notify(struct wmi_device * wdev,union acpi_object * dummy)164 static void yogabook_wmi_notify(struct wmi_device *wdev, union acpi_object *dummy)
165 {
166 	struct yogabook_wmi *data = dev_get_drvdata(&wdev->dev);
167 
168 	if (test_bit(YB_SUSPENDED, &data->flags))
169 		return;
170 
171 	if (test_bit(YB_DIGITIZER_MODE, &data->flags))
172 		clear_bit(YB_DIGITIZER_MODE, &data->flags);
173 	else
174 		set_bit(YB_DIGITIZER_MODE, &data->flags);
175 
176 	/*
177 	 * We are called from the ACPI core and the driver [un]binding which is
178 	 * done also needs ACPI functions, use a workqueue to avoid deadlocking.
179 	 */
180 	schedule_work(&data->work);
181 }
182 
yogabook_backside_hall_irq(int irq,void * _data)183 static irqreturn_t yogabook_backside_hall_irq(int irq, void *_data)
184 {
185 	struct yogabook_wmi *data = _data;
186 
187 	if (gpiod_get_value(data->backside_hall_gpio))
188 		set_bit(YB_TABLET_MODE, &data->flags);
189 	else
190 		clear_bit(YB_TABLET_MODE, &data->flags);
191 
192 	schedule_work(&data->work);
193 
194 	return IRQ_HANDLED;
195 }
196 
kbd_brightness_get(struct led_classdev * cdev)197 static enum led_brightness kbd_brightness_get(struct led_classdev *cdev)
198 {
199 	struct yogabook_wmi *data =
200 		container_of(cdev, struct yogabook_wmi, kbd_bl_led);
201 
202 	return data->brightness;
203 }
204 
kbd_brightness_set(struct led_classdev * cdev,enum led_brightness value)205 static int kbd_brightness_set(struct led_classdev *cdev,
206 			      enum led_brightness value)
207 {
208 	struct yogabook_wmi *data =
209 		container_of(cdev, struct yogabook_wmi, kbd_bl_led);
210 	struct wmi_device *wdev = data->wdev;
211 
212 	if ((value < 0) || (value > 255))
213 		return -EINVAL;
214 
215 	data->brightness = value;
216 
217 	if (data->kbd_adev->power.state != ACPI_STATE_D0)
218 		return 0;
219 
220 	return yogabook_wmi_set_kbd_backlight(wdev, data->brightness);
221 }
222 
223 static struct gpiod_lookup_table yogabook_wmi_gpios = {
224 	.dev_id		= "243FEC1D-1963-41C1-8100-06A9D82A94B4",
225 	.table		= {
226 		GPIO_LOOKUP("INT33FF:02", 18, "backside_hall_sw", GPIO_ACTIVE_LOW),
227 		{}
228 	},
229 };
230 
yogabook_wmi_rm_gpio_lookup(void * unused)231 static void yogabook_wmi_rm_gpio_lookup(void *unused)
232 {
233 	gpiod_remove_lookup_table(&yogabook_wmi_gpios);
234 }
235 
yogabook_wmi_probe(struct wmi_device * wdev,const void * context)236 static int yogabook_wmi_probe(struct wmi_device *wdev, const void *context)
237 {
238 	struct yogabook_wmi *data;
239 	int r;
240 
241 	data = devm_kzalloc(&wdev->dev, sizeof(struct yogabook_wmi), GFP_KERNEL);
242 	if (data == NULL)
243 		return -ENOMEM;
244 
245 	dev_set_drvdata(&wdev->dev, data);
246 
247 	data->wdev = wdev;
248 	data->brightness = YB_KBD_BL_DEFAULT;
249 	set_bit(YB_KBD_IS_ON, &data->flags);
250 	set_bit(YB_DIGITIZER_IS_ON, &data->flags);
251 
252 	r = devm_work_autocancel(&wdev->dev, &data->work, yogabook_wmi_work);
253 	if (r)
254 		return r;
255 
256 	data->kbd_adev = acpi_dev_get_first_match_dev("GDIX1001", NULL, -1);
257 	if (!data->kbd_adev) {
258 		dev_err(&wdev->dev, "Cannot find the touchpad device in ACPI tables\n");
259 		return -ENODEV;
260 	}
261 
262 	data->dig_adev = acpi_dev_get_first_match_dev("WCOM0019", NULL, -1);
263 	if (!data->dig_adev) {
264 		dev_err(&wdev->dev, "Cannot find the digitizer device in ACPI tables\n");
265 		r = -ENODEV;
266 		goto error_put_devs;
267 	}
268 
269 	data->kbd_dev = get_device(acpi_get_first_physical_node(data->kbd_adev));
270 	if (!data->kbd_dev || !data->kbd_dev->driver) {
271 		r = -EPROBE_DEFER;
272 		goto error_put_devs;
273 	}
274 
275 	data->dig_dev = get_device(acpi_get_first_physical_node(data->dig_adev));
276 	if (!data->dig_dev || !data->dig_dev->driver) {
277 		r = -EPROBE_DEFER;
278 		goto error_put_devs;
279 	}
280 
281 	gpiod_add_lookup_table(&yogabook_wmi_gpios);
282 
283 	r = devm_add_action_or_reset(&wdev->dev, yogabook_wmi_rm_gpio_lookup, NULL);
284 	if (r)
285 		goto error_put_devs;
286 
287 	data->backside_hall_gpio =
288 		devm_gpiod_get(&wdev->dev, "backside_hall_sw", GPIOD_IN);
289 	if (IS_ERR(data->backside_hall_gpio)) {
290 		r = PTR_ERR(data->backside_hall_gpio);
291 		dev_err_probe(&wdev->dev, r, "Getting backside_hall_sw GPIO\n");
292 		goto error_put_devs;
293 	}
294 
295 	r = gpiod_to_irq(data->backside_hall_gpio);
296 	if (r < 0) {
297 		dev_err_probe(&wdev->dev, r, "Getting backside_hall_sw IRQ\n");
298 		goto error_put_devs;
299 	}
300 	data->backside_hall_irq = r;
301 
302 	r = devm_request_irq(&wdev->dev, data->backside_hall_irq,
303 			     yogabook_backside_hall_irq,
304 			     IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
305 			     "backside_hall_sw", data);
306 	if (r) {
307 		dev_err_probe(&wdev->dev, r, "Requesting backside_hall_sw IRQ\n");
308 		goto error_put_devs;
309 	}
310 
311 	schedule_work(&data->work);
312 
313 	data->kbd_bl_led.name = "ybwmi::kbd_backlight";
314 	data->kbd_bl_led.brightness_set_blocking = kbd_brightness_set;
315 	data->kbd_bl_led.brightness_get = kbd_brightness_get;
316 	data->kbd_bl_led.max_brightness = 255;
317 
318 	r = devm_led_classdev_register(&wdev->dev, &data->kbd_bl_led);
319 	if (r < 0) {
320 		dev_err_probe(&wdev->dev, r, "Registering backlight LED device\n");
321 		goto error_put_devs;
322 	}
323 
324 	return 0;
325 
326 error_put_devs:
327 	put_device(data->dig_dev);
328 	put_device(data->kbd_dev);
329 	acpi_dev_put(data->dig_adev);
330 	acpi_dev_put(data->kbd_adev);
331 	return r;
332 }
333 
yogabook_wmi_remove(struct wmi_device * wdev)334 static void yogabook_wmi_remove(struct wmi_device *wdev)
335 {
336 	struct yogabook_wmi *data = dev_get_drvdata(&wdev->dev);
337 
338 	put_device(data->dig_dev);
339 	put_device(data->kbd_dev);
340 	acpi_dev_put(data->dig_adev);
341 	acpi_dev_put(data->kbd_adev);
342 }
343 
yogabook_wmi_suspend(struct device * dev)344 static int __maybe_unused yogabook_wmi_suspend(struct device *dev)
345 {
346 	struct wmi_device *wdev = container_of(dev, struct wmi_device, dev);
347 	struct yogabook_wmi *data = dev_get_drvdata(dev);
348 
349 	set_bit(YB_SUSPENDED, &data->flags);
350 
351 	flush_work(&data->work);
352 
353 	/* Turn off the pen button at sleep */
354 	if (test_bit(YB_DIGITIZER_IS_ON, &data->flags))
355 		yogabook_wmi_do_action(wdev, YB_PAD_DISABLE);
356 
357 	return 0;
358 }
359 
yogabook_wmi_resume(struct device * dev)360 static int __maybe_unused yogabook_wmi_resume(struct device *dev)
361 {
362 	struct wmi_device *wdev = container_of(dev, struct wmi_device, dev);
363 	struct yogabook_wmi *data = dev_get_drvdata(dev);
364 
365 	if (test_bit(YB_KBD_IS_ON, &data->flags)) {
366 		/* Ensure keyboard touchpad is on before we call KBLC() */
367 		acpi_device_set_power(data->kbd_adev, ACPI_STATE_D0);
368 		yogabook_wmi_set_kbd_backlight(wdev, data->brightness);
369 	}
370 
371 	if (test_bit(YB_DIGITIZER_IS_ON, &data->flags))
372 		yogabook_wmi_do_action(wdev, YB_PAD_ENABLE);
373 
374 	clear_bit(YB_SUSPENDED, &data->flags);
375 
376 	/* Check for YB_TABLET_MODE changes made during suspend */
377 	schedule_work(&data->work);
378 
379 	return 0;
380 }
381 
382 static const struct wmi_device_id yogabook_wmi_id_table[] = {
383 	{
384 		.guid_string = YB_MBTN_EVENT_GUID,
385 	},
386 	{ } /* Terminating entry */
387 };
388 
389 static SIMPLE_DEV_PM_OPS(yogabook_wmi_pm_ops,
390 			 yogabook_wmi_suspend, yogabook_wmi_resume);
391 
392 static struct wmi_driver yogabook_wmi_driver = {
393 	.driver = {
394 		.name = "yogabook-wmi",
395 		.pm = &yogabook_wmi_pm_ops,
396 	},
397 	.no_notify_data = true,
398 	.id_table = yogabook_wmi_id_table,
399 	.probe = yogabook_wmi_probe,
400 	.remove = yogabook_wmi_remove,
401 	.notify = yogabook_wmi_notify,
402 };
403 module_wmi_driver(yogabook_wmi_driver);
404 
405 MODULE_DEVICE_TABLE(wmi, yogabook_wmi_id_table);
406 MODULE_AUTHOR("Yauhen Kharuzhy");
407 MODULE_DESCRIPTION("Lenovo Yoga Book WMI driver");
408 MODULE_LICENSE("GPL v2");
409