1 // SPDX-License-Identifier: GPL-2.0
2 // Melfas MMS114/MMS152 touchscreen device driver
3 //
4 // Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 // Author: Joonyoung Shim <jy0922.shim@samsung.com>
6 
7 #include <linux/module.h>
8 #include <linux/delay.h>
9 #include <linux/of.h>
10 #include <linux/of_device.h>
11 #include <linux/i2c.h>
12 #include <linux/input/mt.h>
13 #include <linux/input/touchscreen.h>
14 #include <linux/interrupt.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/slab.h>
17 
18 /* Write only registers */
19 #define MMS114_MODE_CONTROL		0x01
20 #define MMS114_OPERATION_MODE_MASK	0xE
21 #define MMS114_ACTIVE			BIT(1)
22 
23 #define MMS114_XY_RESOLUTION_H		0x02
24 #define MMS114_X_RESOLUTION		0x03
25 #define MMS114_Y_RESOLUTION		0x04
26 #define MMS114_CONTACT_THRESHOLD	0x05
27 #define MMS114_MOVING_THRESHOLD		0x06
28 
29 /* Read only registers */
30 #define MMS114_PACKET_SIZE		0x0F
31 #define MMS114_INFORMATION		0x10
32 #define MMS114_TSP_REV			0xF0
33 
34 #define MMS152_FW_REV			0xE1
35 #define MMS152_COMPAT_GROUP		0xF2
36 
37 /* Minimum delay time is 50us between stop and start signal of i2c */
38 #define MMS114_I2C_DELAY		50
39 
40 /* 200ms needs after power on */
41 #define MMS114_POWERON_DELAY		200
42 
43 /* Touchscreen absolute values */
44 #define MMS114_MAX_AREA			0xff
45 
46 #define MMS114_MAX_TOUCH		10
47 #define MMS114_PACKET_NUM		8
48 
49 /* Touch type */
50 #define MMS114_TYPE_NONE		0
51 #define MMS114_TYPE_TOUCHSCREEN		1
52 #define MMS114_TYPE_TOUCHKEY		2
53 
54 enum mms_type {
55 	TYPE_MMS114	= 114,
56 	TYPE_MMS152	= 152,
57 	TYPE_MMS345L	= 345,
58 };
59 
60 struct mms114_data {
61 	struct i2c_client	*client;
62 	struct input_dev	*input_dev;
63 	struct regulator	*core_reg;
64 	struct regulator	*io_reg;
65 	struct touchscreen_properties props;
66 	enum mms_type		type;
67 	unsigned int		contact_threshold;
68 	unsigned int		moving_threshold;
69 
70 	/* Use cache data for mode control register(write only) */
71 	u8			cache_mode_control;
72 };
73 
74 struct mms114_touch {
75 	u8 id:4, reserved_bit4:1, type:2, pressed:1;
76 	u8 x_hi:4, y_hi:4;
77 	u8 x_lo;
78 	u8 y_lo;
79 	u8 width;
80 	u8 strength;
81 	u8 reserved[2];
82 } __packed;
83 
84 static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
85 			     unsigned int len, u8 *val)
86 {
87 	struct i2c_client *client = data->client;
88 	struct i2c_msg xfer[2];
89 	u8 buf = reg & 0xff;
90 	int error;
91 
92 	if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
93 		BUG();
94 
95 	/* Write register */
96 	xfer[0].addr = client->addr;
97 	xfer[0].flags = client->flags & I2C_M_TEN;
98 	xfer[0].len = 1;
99 	xfer[0].buf = &buf;
100 
101 	/* Read data */
102 	xfer[1].addr = client->addr;
103 	xfer[1].flags = (client->flags & I2C_M_TEN) | I2C_M_RD;
104 	xfer[1].len = len;
105 	xfer[1].buf = val;
106 
107 	error = i2c_transfer(client->adapter, xfer, 2);
108 	if (error != 2) {
109 		dev_err(&client->dev,
110 			"%s: i2c transfer failed (%d)\n", __func__, error);
111 		return error < 0 ? error : -EIO;
112 	}
113 	udelay(MMS114_I2C_DELAY);
114 
115 	return 0;
116 }
117 
118 static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
119 {
120 	u8 val;
121 	int error;
122 
123 	if (reg == MMS114_MODE_CONTROL)
124 		return data->cache_mode_control;
125 
126 	error = __mms114_read_reg(data, reg, 1, &val);
127 	return error < 0 ? error : val;
128 }
129 
130 static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
131 			    unsigned int val)
132 {
133 	struct i2c_client *client = data->client;
134 	u8 buf[2];
135 	int error;
136 
137 	buf[0] = reg & 0xff;
138 	buf[1] = val & 0xff;
139 
140 	error = i2c_master_send(client, buf, 2);
141 	if (error != 2) {
142 		dev_err(&client->dev,
143 			"%s: i2c send failed (%d)\n", __func__, error);
144 		return error < 0 ? error : -EIO;
145 	}
146 	udelay(MMS114_I2C_DELAY);
147 
148 	if (reg == MMS114_MODE_CONTROL)
149 		data->cache_mode_control = val;
150 
151 	return 0;
152 }
153 
154 static void mms114_process_mt(struct mms114_data *data, struct mms114_touch *touch)
155 {
156 	struct i2c_client *client = data->client;
157 	struct input_dev *input_dev = data->input_dev;
158 	unsigned int id;
159 	unsigned int x;
160 	unsigned int y;
161 
162 	if (touch->id > MMS114_MAX_TOUCH) {
163 		dev_err(&client->dev, "Wrong touch id (%d)\n", touch->id);
164 		return;
165 	}
166 
167 	if (touch->type != MMS114_TYPE_TOUCHSCREEN) {
168 		dev_err(&client->dev, "Wrong touch type (%d)\n", touch->type);
169 		return;
170 	}
171 
172 	id = touch->id - 1;
173 	x = touch->x_lo | touch->x_hi << 8;
174 	y = touch->y_lo | touch->y_hi << 8;
175 
176 	dev_dbg(&client->dev,
177 		"id: %d, type: %d, pressed: %d, x: %d, y: %d, width: %d, strength: %d\n",
178 		id, touch->type, touch->pressed,
179 		x, y, touch->width, touch->strength);
180 
181 	input_mt_slot(input_dev, id);
182 	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, touch->pressed);
183 
184 	if (touch->pressed) {
185 		touchscreen_report_pos(input_dev, &data->props, x, y, true);
186 		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, touch->width);
187 		input_report_abs(input_dev, ABS_MT_PRESSURE, touch->strength);
188 	}
189 }
190 
191 static irqreturn_t mms114_interrupt(int irq, void *dev_id)
192 {
193 	struct mms114_data *data = dev_id;
194 	struct input_dev *input_dev = data->input_dev;
195 	struct mms114_touch touch[MMS114_MAX_TOUCH];
196 	int packet_size;
197 	int touch_size;
198 	int index;
199 	int error;
200 
201 	mutex_lock(&input_dev->mutex);
202 	if (!input_dev->users) {
203 		mutex_unlock(&input_dev->mutex);
204 		goto out;
205 	}
206 	mutex_unlock(&input_dev->mutex);
207 
208 	packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
209 	if (packet_size <= 0)
210 		goto out;
211 
212 	touch_size = packet_size / MMS114_PACKET_NUM;
213 
214 	error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size,
215 			(u8 *)touch);
216 	if (error < 0)
217 		goto out;
218 
219 	for (index = 0; index < touch_size; index++)
220 		mms114_process_mt(data, touch + index);
221 
222 	input_mt_report_pointer_emulation(data->input_dev, true);
223 	input_sync(data->input_dev);
224 
225 out:
226 	return IRQ_HANDLED;
227 }
228 
229 static int mms114_set_active(struct mms114_data *data, bool active)
230 {
231 	int val;
232 
233 	val = mms114_read_reg(data, MMS114_MODE_CONTROL);
234 	if (val < 0)
235 		return val;
236 
237 	val &= ~MMS114_OPERATION_MODE_MASK;
238 
239 	/* If active is false, sleep mode */
240 	if (active)
241 		val |= MMS114_ACTIVE;
242 
243 	return mms114_write_reg(data, MMS114_MODE_CONTROL, val);
244 }
245 
246 static int mms114_get_version(struct mms114_data *data)
247 {
248 	struct device *dev = &data->client->dev;
249 	u8 buf[6];
250 	int group;
251 	int error;
252 
253 	switch (data->type) {
254 	case TYPE_MMS345L:
255 		error = __mms114_read_reg(data, MMS152_FW_REV, 3, buf);
256 		if (error)
257 			return error;
258 
259 		dev_info(dev, "TSP FW Rev: bootloader 0x%x / core 0x%x / config 0x%x\n",
260 			 buf[0], buf[1], buf[2]);
261 		break;
262 
263 	case TYPE_MMS152:
264 		error = __mms114_read_reg(data, MMS152_FW_REV, 3, buf);
265 		if (error)
266 			return error;
267 
268 		group = i2c_smbus_read_byte_data(data->client,
269 						  MMS152_COMPAT_GROUP);
270 		if (group < 0)
271 			return group;
272 
273 		dev_info(dev, "TSP FW Rev: bootloader 0x%x / core 0x%x / config 0x%x, Compat group: %c\n",
274 			 buf[0], buf[1], buf[2], group);
275 		break;
276 
277 	case TYPE_MMS114:
278 		error = __mms114_read_reg(data, MMS114_TSP_REV, 6, buf);
279 		if (error)
280 			return error;
281 
282 		dev_info(dev, "TSP Rev: 0x%x, HW Rev: 0x%x, Firmware Ver: 0x%x\n",
283 			 buf[0], buf[1], buf[3]);
284 		break;
285 	}
286 
287 	return 0;
288 }
289 
290 static int mms114_setup_regs(struct mms114_data *data)
291 {
292 	const struct touchscreen_properties *props = &data->props;
293 	int val;
294 	int error;
295 
296 	error = mms114_get_version(data);
297 	if (error < 0)
298 		return error;
299 
300 	/* Only MMS114 has configuration and power on registers */
301 	if (data->type != TYPE_MMS114)
302 		return 0;
303 
304 	error = mms114_set_active(data, true);
305 	if (error < 0)
306 		return error;
307 
308 	val = (props->max_x >> 8) & 0xf;
309 	val |= ((props->max_y >> 8) & 0xf) << 4;
310 	error = mms114_write_reg(data, MMS114_XY_RESOLUTION_H, val);
311 	if (error < 0)
312 		return error;
313 
314 	val = props->max_x & 0xff;
315 	error = mms114_write_reg(data, MMS114_X_RESOLUTION, val);
316 	if (error < 0)
317 		return error;
318 
319 	val = props->max_x & 0xff;
320 	error = mms114_write_reg(data, MMS114_Y_RESOLUTION, val);
321 	if (error < 0)
322 		return error;
323 
324 	if (data->contact_threshold) {
325 		error = mms114_write_reg(data, MMS114_CONTACT_THRESHOLD,
326 				data->contact_threshold);
327 		if (error < 0)
328 			return error;
329 	}
330 
331 	if (data->moving_threshold) {
332 		error = mms114_write_reg(data, MMS114_MOVING_THRESHOLD,
333 				data->moving_threshold);
334 		if (error < 0)
335 			return error;
336 	}
337 
338 	return 0;
339 }
340 
341 static int mms114_start(struct mms114_data *data)
342 {
343 	struct i2c_client *client = data->client;
344 	int error;
345 
346 	error = regulator_enable(data->core_reg);
347 	if (error) {
348 		dev_err(&client->dev, "Failed to enable avdd: %d\n", error);
349 		return error;
350 	}
351 
352 	error = regulator_enable(data->io_reg);
353 	if (error) {
354 		dev_err(&client->dev, "Failed to enable vdd: %d\n", error);
355 		regulator_disable(data->core_reg);
356 		return error;
357 	}
358 
359 	msleep(MMS114_POWERON_DELAY);
360 
361 	error = mms114_setup_regs(data);
362 	if (error < 0) {
363 		regulator_disable(data->io_reg);
364 		regulator_disable(data->core_reg);
365 		return error;
366 	}
367 
368 	enable_irq(client->irq);
369 
370 	return 0;
371 }
372 
373 static void mms114_stop(struct mms114_data *data)
374 {
375 	struct i2c_client *client = data->client;
376 	int error;
377 
378 	disable_irq(client->irq);
379 
380 	error = regulator_disable(data->io_reg);
381 	if (error)
382 		dev_warn(&client->dev, "Failed to disable vdd: %d\n", error);
383 
384 	error = regulator_disable(data->core_reg);
385 	if (error)
386 		dev_warn(&client->dev, "Failed to disable avdd: %d\n", error);
387 }
388 
389 static int mms114_input_open(struct input_dev *dev)
390 {
391 	struct mms114_data *data = input_get_drvdata(dev);
392 
393 	return mms114_start(data);
394 }
395 
396 static void mms114_input_close(struct input_dev *dev)
397 {
398 	struct mms114_data *data = input_get_drvdata(dev);
399 
400 	mms114_stop(data);
401 }
402 
403 static int mms114_parse_legacy_bindings(struct mms114_data *data)
404 {
405 	struct device *dev = &data->client->dev;
406 	struct touchscreen_properties *props = &data->props;
407 
408 	if (device_property_read_u32(dev, "x-size", &props->max_x)) {
409 		dev_dbg(dev, "failed to get legacy x-size property\n");
410 		return -EINVAL;
411 	}
412 
413 	if (device_property_read_u32(dev, "y-size", &props->max_y)) {
414 		dev_dbg(dev, "failed to get legacy y-size property\n");
415 		return -EINVAL;
416 	}
417 
418 	device_property_read_u32(dev, "contact-threshold",
419 				&data->contact_threshold);
420 	device_property_read_u32(dev, "moving-threshold",
421 				&data->moving_threshold);
422 
423 	if (device_property_read_bool(dev, "x-invert"))
424 		props->invert_x = true;
425 	if (device_property_read_bool(dev, "y-invert"))
426 		props->invert_y = true;
427 
428 	props->swap_x_y = false;
429 
430 	return 0;
431 }
432 
433 static int mms114_probe(struct i2c_client *client,
434 				  const struct i2c_device_id *id)
435 {
436 	struct mms114_data *data;
437 	struct input_dev *input_dev;
438 	const void *match_data;
439 	int error;
440 
441 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
442 		dev_err(&client->dev, "Not supported I2C adapter\n");
443 		return -ENODEV;
444 	}
445 
446 	data = devm_kzalloc(&client->dev, sizeof(struct mms114_data),
447 			    GFP_KERNEL);
448 	input_dev = devm_input_allocate_device(&client->dev);
449 	if (!data || !input_dev) {
450 		dev_err(&client->dev, "Failed to allocate memory\n");
451 		return -ENOMEM;
452 	}
453 
454 	data->client = client;
455 	data->input_dev = input_dev;
456 
457 	match_data = device_get_match_data(&client->dev);
458 	if (!match_data)
459 		return -EINVAL;
460 
461 	data->type = (enum mms_type)match_data;
462 
463 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
464 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
465 	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
466 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
467 			     0, MMS114_MAX_AREA, 0, 0);
468 
469 	touchscreen_parse_properties(input_dev, true, &data->props);
470 	if (!data->props.max_x || !data->props.max_y) {
471 		dev_dbg(&client->dev,
472 			"missing X/Y size properties, trying legacy bindings\n");
473 		error = mms114_parse_legacy_bindings(data);
474 		if (error)
475 			return error;
476 
477 		input_set_abs_params(input_dev, ABS_MT_POSITION_X,
478 				     0, data->props.max_x, 0, 0);
479 		input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
480 				     0, data->props.max_y, 0, 0);
481 	}
482 
483 	if (data->type == TYPE_MMS114) {
484 		/*
485 		 * The firmware handles movement and pressure fuzz, so
486 		 * don't duplicate that in software.
487 		 */
488 		data->moving_threshold = input_abs_get_fuzz(input_dev,
489 							    ABS_MT_POSITION_X);
490 		data->contact_threshold = input_abs_get_fuzz(input_dev,
491 							     ABS_MT_PRESSURE);
492 		input_abs_set_fuzz(input_dev, ABS_MT_POSITION_X, 0);
493 		input_abs_set_fuzz(input_dev, ABS_MT_POSITION_Y, 0);
494 		input_abs_set_fuzz(input_dev, ABS_MT_PRESSURE, 0);
495 	}
496 
497 	input_dev->name = devm_kasprintf(&client->dev, GFP_KERNEL,
498 					 "MELFAS MMS%d Touchscreen",
499 					 data->type);
500 	if (!input_dev->name)
501 		return -ENOMEM;
502 
503 	input_dev->id.bustype = BUS_I2C;
504 	input_dev->dev.parent = &client->dev;
505 	input_dev->open = mms114_input_open;
506 	input_dev->close = mms114_input_close;
507 
508 	error = input_mt_init_slots(input_dev, MMS114_MAX_TOUCH,
509 				    INPUT_MT_DIRECT);
510 	if (error)
511 		return error;
512 
513 	input_set_drvdata(input_dev, data);
514 	i2c_set_clientdata(client, data);
515 
516 	data->core_reg = devm_regulator_get(&client->dev, "avdd");
517 	if (IS_ERR(data->core_reg)) {
518 		error = PTR_ERR(data->core_reg);
519 		dev_err(&client->dev,
520 			"Unable to get the Core regulator (%d)\n", error);
521 		return error;
522 	}
523 
524 	data->io_reg = devm_regulator_get(&client->dev, "vdd");
525 	if (IS_ERR(data->io_reg)) {
526 		error = PTR_ERR(data->io_reg);
527 		dev_err(&client->dev,
528 			"Unable to get the IO regulator (%d)\n", error);
529 		return error;
530 	}
531 
532 	error = devm_request_threaded_irq(&client->dev, client->irq,
533 					  NULL, mms114_interrupt, IRQF_ONESHOT,
534 					  dev_name(&client->dev), data);
535 	if (error) {
536 		dev_err(&client->dev, "Failed to register interrupt\n");
537 		return error;
538 	}
539 	disable_irq(client->irq);
540 
541 	error = input_register_device(data->input_dev);
542 	if (error) {
543 		dev_err(&client->dev, "Failed to register input device\n");
544 		return error;
545 	}
546 
547 	return 0;
548 }
549 
550 static int __maybe_unused mms114_suspend(struct device *dev)
551 {
552 	struct i2c_client *client = to_i2c_client(dev);
553 	struct mms114_data *data = i2c_get_clientdata(client);
554 	struct input_dev *input_dev = data->input_dev;
555 	int id;
556 
557 	/* Release all touch */
558 	for (id = 0; id < MMS114_MAX_TOUCH; id++) {
559 		input_mt_slot(input_dev, id);
560 		input_mt_report_slot_inactive(input_dev);
561 	}
562 
563 	input_mt_report_pointer_emulation(input_dev, true);
564 	input_sync(input_dev);
565 
566 	mutex_lock(&input_dev->mutex);
567 	if (input_dev->users)
568 		mms114_stop(data);
569 	mutex_unlock(&input_dev->mutex);
570 
571 	return 0;
572 }
573 
574 static int __maybe_unused mms114_resume(struct device *dev)
575 {
576 	struct i2c_client *client = to_i2c_client(dev);
577 	struct mms114_data *data = i2c_get_clientdata(client);
578 	struct input_dev *input_dev = data->input_dev;
579 	int error;
580 
581 	mutex_lock(&input_dev->mutex);
582 	if (input_dev->users) {
583 		error = mms114_start(data);
584 		if (error < 0) {
585 			mutex_unlock(&input_dev->mutex);
586 			return error;
587 		}
588 	}
589 	mutex_unlock(&input_dev->mutex);
590 
591 	return 0;
592 }
593 
594 static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);
595 
596 static const struct i2c_device_id mms114_id[] = {
597 	{ "mms114", 0 },
598 	{ }
599 };
600 MODULE_DEVICE_TABLE(i2c, mms114_id);
601 
602 #ifdef CONFIG_OF
603 static const struct of_device_id mms114_dt_match[] = {
604 	{
605 		.compatible = "melfas,mms114",
606 		.data = (void *)TYPE_MMS114,
607 	}, {
608 		.compatible = "melfas,mms152",
609 		.data = (void *)TYPE_MMS152,
610 	}, {
611 		.compatible = "melfas,mms345l",
612 		.data = (void *)TYPE_MMS345L,
613 	},
614 	{ }
615 };
616 MODULE_DEVICE_TABLE(of, mms114_dt_match);
617 #endif
618 
619 static struct i2c_driver mms114_driver = {
620 	.driver = {
621 		.name	= "mms114",
622 		.pm	= &mms114_pm_ops,
623 		.of_match_table = of_match_ptr(mms114_dt_match),
624 	},
625 	.probe		= mms114_probe,
626 	.id_table	= mms114_id,
627 };
628 
629 module_i2c_driver(mms114_driver);
630 
631 /* Module information */
632 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
633 MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
634 MODULE_LICENSE("GPL v2");
635