xref: /linux/drivers/platform/x86/lenovo-yogabook.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Platform driver for Lenovo Yoga Book YB1-X90F/L tablets (Android model)
4  * WMI driver for Lenovo Yoga Book YB1-X91F/L tablets (Windows model)
5  *
6  * The keyboard half of the YB1 models can function as both a capacitive
7  * touch keyboard or as a Wacom digitizer, but not at the same time.
8  *
9  * This driver takes care of switching between the 2 functions.
10  *
11  * Copyright 2023 Hans de Goede <hansg@kernel.org>
12  */
13 
14 #include <linux/acpi.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/gpio/machine.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/leds.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/pwm.h>
23 #include <linux/wmi.h>
24 #include <linux/workqueue.h>
25 
26 #define YB_MBTN_EVENT_GUID	"243FEC1D-1963-41C1-8100-06A9D82A94B4"
27 
28 #define YB_KBD_BL_DEFAULT	128
29 #define YB_KBD_BL_MAX		255
30 #define YB_KBD_BL_PWM_PERIOD	13333
31 
32 #define YB_PDEV_NAME		"yogabook-touch-kbd-digitizer-switch"
33 
34 /* flags */
35 enum {
36 	YB_KBD_IS_ON,
37 	YB_DIGITIZER_IS_ON,
38 	YB_DIGITIZER_MODE,
39 	YB_TABLET_MODE,
40 	YB_SUSPENDED,
41 };
42 
43 struct yogabook_data {
44 	struct device *dev;
45 	struct acpi_device *kbd_adev;
46 	struct acpi_device *dig_adev;
47 	struct device *kbd_dev;
48 	struct device *dig_dev;
49 	struct led_classdev *pen_led;
50 	struct gpio_desc *pen_touch_event;
51 	struct gpio_desc *kbd_bl_led_enable;
52 	struct gpio_desc *backside_hall_gpio;
53 	struct pwm_device *kbd_bl_pwm;
54 	int (*set_kbd_backlight)(struct yogabook_data *data, uint8_t level);
55 	int pen_touch_irq;
56 	int backside_hall_irq;
57 	struct work_struct work;
58 	struct led_classdev kbd_bl_led;
59 	unsigned long flags;
60 	uint8_t brightness;
61 };
62 
63 static void yogabook_work(struct work_struct *work)
64 {
65 	struct yogabook_data *data = container_of(work, struct yogabook_data, work);
66 	bool kbd_on, digitizer_on;
67 	int r;
68 
69 	if (test_bit(YB_SUSPENDED, &data->flags))
70 		return;
71 
72 	if (test_bit(YB_TABLET_MODE, &data->flags)) {
73 		kbd_on = false;
74 		digitizer_on = false;
75 	} else if (test_bit(YB_DIGITIZER_MODE, &data->flags)) {
76 		digitizer_on = true;
77 		kbd_on = false;
78 	} else {
79 		kbd_on = true;
80 		digitizer_on = false;
81 	}
82 
83 	if (!kbd_on && test_bit(YB_KBD_IS_ON, &data->flags)) {
84 		/*
85 		 * Must be done before releasing the keyboard touchscreen driver,
86 		 * so that the keyboard touchscreen dev is still in D0.
87 		 */
88 		data->set_kbd_backlight(data, 0);
89 		device_release_driver(data->kbd_dev);
90 		clear_bit(YB_KBD_IS_ON, &data->flags);
91 	}
92 
93 	if (!digitizer_on && test_bit(YB_DIGITIZER_IS_ON, &data->flags)) {
94 		led_set_brightness(data->pen_led, LED_OFF);
95 		device_release_driver(data->dig_dev);
96 		clear_bit(YB_DIGITIZER_IS_ON, &data->flags);
97 	}
98 
99 	if (kbd_on && !test_bit(YB_KBD_IS_ON, &data->flags)) {
100 		r = device_reprobe(data->kbd_dev);
101 		if (r)
102 			dev_warn(data->dev, "Reprobe of keyboard touchscreen failed: %d\n", r);
103 
104 		data->set_kbd_backlight(data, data->brightness);
105 		set_bit(YB_KBD_IS_ON, &data->flags);
106 	}
107 
108 	if (digitizer_on && !test_bit(YB_DIGITIZER_IS_ON, &data->flags)) {
109 		r = device_reprobe(data->dig_dev);
110 		if (r)
111 			dev_warn(data->dev, "Reprobe of digitizer failed: %d\n", r);
112 
113 		led_set_brightness(data->pen_led, LED_FULL);
114 		set_bit(YB_DIGITIZER_IS_ON, &data->flags);
115 	}
116 }
117 
118 static void yogabook_toggle_digitizer_mode(struct yogabook_data *data)
119 {
120 	if (test_bit(YB_SUSPENDED, &data->flags))
121 		return;
122 
123 	if (test_bit(YB_DIGITIZER_MODE, &data->flags))
124 		clear_bit(YB_DIGITIZER_MODE, &data->flags);
125 	else
126 		set_bit(YB_DIGITIZER_MODE, &data->flags);
127 
128 	/*
129 	 * We are called from the ACPI core and the driver [un]binding which is
130 	 * done also needs ACPI functions, use a workqueue to avoid deadlocking.
131 	 */
132 	schedule_work(&data->work);
133 }
134 
135 static irqreturn_t yogabook_backside_hall_irq(int irq, void *_data)
136 {
137 	struct yogabook_data *data = _data;
138 
139 	if (gpiod_get_value(data->backside_hall_gpio))
140 		set_bit(YB_TABLET_MODE, &data->flags);
141 	else
142 		clear_bit(YB_TABLET_MODE, &data->flags);
143 
144 	schedule_work(&data->work);
145 
146 	return IRQ_HANDLED;
147 }
148 
149 #define kbd_led_to_yogabook(cdev) container_of(cdev, struct yogabook_data, kbd_bl_led)
150 
151 static enum led_brightness kbd_brightness_get(struct led_classdev *cdev)
152 {
153 	struct yogabook_data *data = kbd_led_to_yogabook(cdev);
154 
155 	return data->brightness;
156 }
157 
158 static int kbd_brightness_set(struct led_classdev *cdev,
159 			      enum led_brightness value)
160 {
161 	struct yogabook_data *data = kbd_led_to_yogabook(cdev);
162 
163 	if ((value < 0) || (value > YB_KBD_BL_MAX))
164 		return -EINVAL;
165 
166 	data->brightness = value;
167 
168 	if (!test_bit(YB_KBD_IS_ON, &data->flags))
169 		return 0;
170 
171 	return data->set_kbd_backlight(data, data->brightness);
172 }
173 
174 static struct gpiod_lookup_table yogabook_gpios = {
175 	.table = {
176 		GPIO_LOOKUP("INT33FF:02", 18, "backside_hall_sw", GPIO_ACTIVE_LOW),
177 		{}
178 	},
179 };
180 
181 static struct led_lookup_data yogabook_pen_led = {
182 	.provider = "platform::indicator",
183 	.con_id = "pen-icon-led",
184 };
185 
186 static int yogabook_probe(struct device *dev, struct yogabook_data *data,
187 			  const char *kbd_bl_led_name)
188 {
189 	int r;
190 
191 	data->dev = dev;
192 	data->brightness = YB_KBD_BL_DEFAULT;
193 	set_bit(YB_KBD_IS_ON, &data->flags);
194 	set_bit(YB_DIGITIZER_IS_ON, &data->flags);
195 	INIT_WORK(&data->work, yogabook_work);
196 
197 	yogabook_pen_led.dev_id = dev_name(dev);
198 	led_add_lookup(&yogabook_pen_led);
199 	data->pen_led = devm_led_get(dev, "pen-icon-led");
200 	led_remove_lookup(&yogabook_pen_led);
201 
202 	if (IS_ERR(data->pen_led))
203 		return dev_err_probe(dev, PTR_ERR(data->pen_led), "Getting pen icon LED\n");
204 
205 	yogabook_gpios.dev_id = dev_name(dev);
206 	gpiod_add_lookup_table(&yogabook_gpios);
207 	data->backside_hall_gpio = devm_gpiod_get(dev, "backside_hall_sw", GPIOD_IN);
208 	gpiod_remove_lookup_table(&yogabook_gpios);
209 
210 	if (IS_ERR(data->backside_hall_gpio))
211 		return dev_err_probe(dev, PTR_ERR(data->backside_hall_gpio),
212 				     "Getting backside_hall_sw GPIO\n");
213 
214 	r = gpiod_to_irq(data->backside_hall_gpio);
215 	if (r < 0)
216 		return dev_err_probe(dev, r, "Getting backside_hall_sw IRQ\n");
217 
218 	data->backside_hall_irq = r;
219 
220 	/* Set default brightness before enabling the IRQ */
221 	data->set_kbd_backlight(data, YB_KBD_BL_DEFAULT);
222 
223 	r = request_irq(data->backside_hall_irq, yogabook_backside_hall_irq,
224 			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
225 			"backside_hall_sw", data);
226 	if (r)
227 		return dev_err_probe(dev, r, "Requesting backside_hall_sw IRQ\n");
228 
229 	schedule_work(&data->work);
230 
231 	data->kbd_bl_led.name = kbd_bl_led_name;
232 	data->kbd_bl_led.brightness_set_blocking = kbd_brightness_set;
233 	data->kbd_bl_led.brightness_get = kbd_brightness_get;
234 	data->kbd_bl_led.max_brightness = YB_KBD_BL_MAX;
235 
236 	r = devm_led_classdev_register(dev, &data->kbd_bl_led);
237 	if (r < 0) {
238 		dev_err_probe(dev, r, "Registering backlight LED device\n");
239 		goto error_free_irq;
240 	}
241 
242 	dev_set_drvdata(dev, data);
243 	return 0;
244 
245 error_free_irq:
246 	free_irq(data->backside_hall_irq, data);
247 	cancel_work_sync(&data->work);
248 	return r;
249 }
250 
251 static void yogabook_remove(struct yogabook_data *data)
252 {
253 	int r = 0;
254 
255 	free_irq(data->backside_hall_irq, data);
256 	cancel_work_sync(&data->work);
257 
258 	if (!test_bit(YB_KBD_IS_ON, &data->flags))
259 		r |= device_reprobe(data->kbd_dev);
260 
261 	if (!test_bit(YB_DIGITIZER_IS_ON, &data->flags))
262 		r |= device_reprobe(data->dig_dev);
263 
264 	if (r)
265 		dev_warn(data->dev, "Reprobe of devices failed\n");
266 }
267 
268 static int yogabook_suspend(struct device *dev)
269 {
270 	struct yogabook_data *data = dev_get_drvdata(dev);
271 
272 	set_bit(YB_SUSPENDED, &data->flags);
273 	flush_work(&data->work);
274 
275 	if (test_bit(YB_KBD_IS_ON, &data->flags))
276 		data->set_kbd_backlight(data, 0);
277 
278 	return 0;
279 }
280 
281 static int yogabook_resume(struct device *dev)
282 {
283 	struct yogabook_data *data = dev_get_drvdata(dev);
284 
285 	if (test_bit(YB_KBD_IS_ON, &data->flags))
286 		data->set_kbd_backlight(data, data->brightness);
287 
288 	clear_bit(YB_SUSPENDED, &data->flags);
289 
290 	/* Check for YB_TABLET_MODE changes made during suspend */
291 	schedule_work(&data->work);
292 
293 	return 0;
294 }
295 
296 static DEFINE_SIMPLE_DEV_PM_OPS(yogabook_pm_ops, yogabook_suspend, yogabook_resume);
297 
298 /********** WMI driver code **********/
299 
300 /*
301  * To control keyboard backlight, call the method KBLC() of the TCS1 ACPI
302  * device (Goodix touchpad acts as virtual sensor keyboard).
303  */
304 static int yogabook_wmi_set_kbd_backlight(struct yogabook_data *data,
305 					  uint8_t level)
306 {
307 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
308 	struct acpi_object_list input;
309 	union acpi_object param;
310 	acpi_status status;
311 
312 	dev_dbg(data->dev, "Set KBLC level to %u\n", level);
313 
314 	/* Ensure keyboard touchpad is on before we call KBLC() */
315 	acpi_device_set_power(data->kbd_adev, ACPI_STATE_D0);
316 
317 	input.count = 1;
318 	input.pointer = &param;
319 
320 	param.type = ACPI_TYPE_INTEGER;
321 	param.integer.value = YB_KBD_BL_MAX - level;
322 
323 	status = acpi_evaluate_object(acpi_device_handle(data->kbd_adev), "KBLC",
324 				      &input, &output);
325 	if (ACPI_FAILURE(status)) {
326 		dev_err(data->dev, "Failed to call KBLC method: 0x%x\n", status);
327 		return status;
328 	}
329 
330 	kfree(output.pointer);
331 	return 0;
332 }
333 
334 static int yogabook_wmi_probe(struct wmi_device *wdev, const void *context)
335 {
336 	struct device *dev = &wdev->dev;
337 	struct yogabook_data *data;
338 	int r;
339 
340 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
341 	if (data == NULL)
342 		return -ENOMEM;
343 
344 	data->kbd_adev = acpi_dev_get_first_match_dev("GDIX1001", NULL, -1);
345 	if (!data->kbd_adev)
346 		return dev_err_probe(dev, -ENODEV, "Cannot find the touchpad device in ACPI tables\n");
347 
348 	data->dig_adev = acpi_dev_get_first_match_dev("WCOM0019", NULL, -1);
349 	if (!data->dig_adev) {
350 		r = dev_err_probe(dev, -ENODEV, "Cannot find the digitizer device in ACPI tables\n");
351 		goto error_put_devs;
352 	}
353 
354 	data->kbd_dev = get_device(acpi_get_first_physical_node(data->kbd_adev));
355 	if (!data->kbd_dev || !data->kbd_dev->driver) {
356 		r = -EPROBE_DEFER;
357 		goto error_put_devs;
358 	}
359 
360 	data->dig_dev = get_device(acpi_get_first_physical_node(data->dig_adev));
361 	if (!data->dig_dev || !data->dig_dev->driver) {
362 		r = -EPROBE_DEFER;
363 		goto error_put_devs;
364 	}
365 
366 	data->set_kbd_backlight = yogabook_wmi_set_kbd_backlight;
367 
368 	r = yogabook_probe(dev, data, "ybwmi::kbd_backlight");
369 	if (r)
370 		goto error_put_devs;
371 
372 	return 0;
373 
374 error_put_devs:
375 	put_device(data->dig_dev);
376 	put_device(data->kbd_dev);
377 	acpi_dev_put(data->dig_adev);
378 	acpi_dev_put(data->kbd_adev);
379 	return r;
380 }
381 
382 static void yogabook_wmi_remove(struct wmi_device *wdev)
383 {
384 	struct yogabook_data *data = dev_get_drvdata(&wdev->dev);
385 
386 	yogabook_remove(data);
387 
388 	put_device(data->dig_dev);
389 	put_device(data->kbd_dev);
390 	acpi_dev_put(data->dig_adev);
391 	acpi_dev_put(data->kbd_adev);
392 }
393 
394 static void yogabook_wmi_notify(struct wmi_device *wdev, union acpi_object *dummy)
395 {
396 	yogabook_toggle_digitizer_mode(dev_get_drvdata(&wdev->dev));
397 }
398 
399 static const struct wmi_device_id yogabook_wmi_id_table[] = {
400 	{
401 		.guid_string = YB_MBTN_EVENT_GUID,
402 	},
403 	{ } /* Terminating entry */
404 };
405 MODULE_DEVICE_TABLE(wmi, yogabook_wmi_id_table);
406 
407 static struct wmi_driver yogabook_wmi_driver = {
408 	.driver = {
409 		.name = "yogabook-wmi",
410 		.pm = pm_sleep_ptr(&yogabook_pm_ops),
411 	},
412 	.no_notify_data = true,
413 	.id_table = yogabook_wmi_id_table,
414 	.probe = yogabook_wmi_probe,
415 	.remove = yogabook_wmi_remove,
416 	.notify = yogabook_wmi_notify,
417 };
418 
419 /********** platform driver code **********/
420 
421 static struct gpiod_lookup_table yogabook_pdev_gpios = {
422 	.dev_id = YB_PDEV_NAME,
423 	.table = {
424 		GPIO_LOOKUP("INT33FF:00", 95, "pen_touch_event", GPIO_ACTIVE_HIGH),
425 		GPIO_LOOKUP("INT33FF:03", 52, "enable_keyboard_led", GPIO_ACTIVE_HIGH),
426 		{}
427 	},
428 };
429 
430 static int yogabook_pdev_set_kbd_backlight(struct yogabook_data *data, u8 level)
431 {
432 	struct pwm_state state = {
433 		.period = YB_KBD_BL_PWM_PERIOD,
434 		.duty_cycle = YB_KBD_BL_PWM_PERIOD * level / YB_KBD_BL_MAX,
435 		.enabled = level,
436 	};
437 
438 	pwm_apply_might_sleep(data->kbd_bl_pwm, &state);
439 	gpiod_set_value(data->kbd_bl_led_enable, level ? 1 : 0);
440 	return 0;
441 }
442 
443 static irqreturn_t yogabook_pen_touch_irq(int irq, void *data)
444 {
445 	yogabook_toggle_digitizer_mode(data);
446 	return IRQ_HANDLED;
447 }
448 
449 static int yogabook_pdev_probe(struct platform_device *pdev)
450 {
451 	struct device *dev = &pdev->dev;
452 	struct yogabook_data *data;
453 	int r;
454 
455 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
456 	if (data == NULL)
457 		return -ENOMEM;
458 
459 	data->kbd_dev = bus_find_device_by_name(&i2c_bus_type, NULL, "i2c-goodix_ts");
460 	if (!data->kbd_dev || !data->kbd_dev->driver) {
461 		r = -EPROBE_DEFER;
462 		goto error_put_devs;
463 	}
464 
465 	data->dig_dev = bus_find_device_by_name(&i2c_bus_type, NULL, "i2c-wacom");
466 	if (!data->dig_dev || !data->dig_dev->driver) {
467 		r = -EPROBE_DEFER;
468 		goto error_put_devs;
469 	}
470 
471 	gpiod_add_lookup_table(&yogabook_pdev_gpios);
472 	data->pen_touch_event = devm_gpiod_get(dev, "pen_touch_event", GPIOD_IN);
473 	data->kbd_bl_led_enable = devm_gpiod_get(dev, "enable_keyboard_led", GPIOD_OUT_HIGH);
474 	gpiod_remove_lookup_table(&yogabook_pdev_gpios);
475 
476 	if (IS_ERR(data->pen_touch_event)) {
477 		r = dev_err_probe(dev, PTR_ERR(data->pen_touch_event),
478 				  "Getting pen_touch_event GPIO\n");
479 		goto error_put_devs;
480 	}
481 
482 	if (IS_ERR(data->kbd_bl_led_enable)) {
483 		r = dev_err_probe(dev, PTR_ERR(data->kbd_bl_led_enable),
484 				  "Getting enable_keyboard_led GPIO\n");
485 		goto error_put_devs;
486 	}
487 
488 	data->kbd_bl_pwm = devm_pwm_get(dev, "pwm_soc_lpss_2");
489 	if (IS_ERR(data->kbd_bl_pwm)) {
490 		r = dev_err_probe(dev, PTR_ERR(data->kbd_bl_pwm),
491 				  "Getting keyboard backlight PWM\n");
492 		goto error_put_devs;
493 	}
494 
495 	r = gpiod_to_irq(data->pen_touch_event);
496 	if (r < 0) {
497 		dev_err_probe(dev, r, "Getting pen_touch_event IRQ\n");
498 		goto error_put_devs;
499 	}
500 	data->pen_touch_irq = r;
501 
502 	r = request_irq(data->pen_touch_irq, yogabook_pen_touch_irq, IRQF_TRIGGER_FALLING,
503 			"pen_touch_event", data);
504 	if (r) {
505 		dev_err_probe(dev, r, "Requesting pen_touch_event IRQ\n");
506 		goto error_put_devs;
507 	}
508 
509 	data->set_kbd_backlight = yogabook_pdev_set_kbd_backlight;
510 
511 	r = yogabook_probe(dev, data, "yogabook::kbd_backlight");
512 	if (r)
513 		goto error_free_irq;
514 
515 	return 0;
516 
517 error_free_irq:
518 	free_irq(data->pen_touch_irq, data);
519 	cancel_work_sync(&data->work);
520 error_put_devs:
521 	put_device(data->dig_dev);
522 	put_device(data->kbd_dev);
523 	return r;
524 }
525 
526 static void yogabook_pdev_remove(struct platform_device *pdev)
527 {
528 	struct yogabook_data *data = platform_get_drvdata(pdev);
529 
530 	yogabook_remove(data);
531 	free_irq(data->pen_touch_irq, data);
532 	cancel_work_sync(&data->work);
533 	put_device(data->dig_dev);
534 	put_device(data->kbd_dev);
535 }
536 
537 static struct platform_driver yogabook_pdev_driver = {
538 	.probe = yogabook_pdev_probe,
539 	.remove_new = yogabook_pdev_remove,
540 	.driver = {
541 		.name = YB_PDEV_NAME,
542 		.pm = pm_sleep_ptr(&yogabook_pm_ops),
543 	},
544 };
545 
546 static int __init yogabook_module_init(void)
547 {
548 	int r;
549 
550 	r = wmi_driver_register(&yogabook_wmi_driver);
551 	if (r)
552 		return r;
553 
554 	r = platform_driver_register(&yogabook_pdev_driver);
555 	if (r)
556 		wmi_driver_unregister(&yogabook_wmi_driver);
557 
558 	return r;
559 }
560 
561 static void __exit yogabook_module_exit(void)
562 {
563 	platform_driver_unregister(&yogabook_pdev_driver);
564 	wmi_driver_unregister(&yogabook_wmi_driver);
565 }
566 
567 module_init(yogabook_module_init);
568 module_exit(yogabook_module_exit);
569 
570 MODULE_ALIAS("platform:" YB_PDEV_NAME);
571 MODULE_AUTHOR("Yauhen Kharuzhy");
572 MODULE_DESCRIPTION("Lenovo Yoga Book driver");
573 MODULE_LICENSE("GPL v2");
574