1 /*
2  * Copyright (C) 2012 Samsung Electronics Co.Ltd
3  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/delay.h>
12 #include <linux/of.h>
13 #include <linux/i2c.h>
14 #include <linux/i2c/mms114.h>
15 #include <linux/input/mt.h>
16 #include <linux/interrupt.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/slab.h>
19 
20 /* Write only registers */
21 #define MMS114_MODE_CONTROL		0x01
22 #define MMS114_OPERATION_MODE_MASK	0xE
23 #define MMS114_ACTIVE			(1 << 1)
24 
25 #define MMS114_XY_RESOLUTION_H		0x02
26 #define MMS114_X_RESOLUTION		0x03
27 #define MMS114_Y_RESOLUTION		0x04
28 #define MMS114_CONTACT_THRESHOLD	0x05
29 #define MMS114_MOVING_THRESHOLD		0x06
30 
31 /* Read only registers */
32 #define MMS114_PACKET_SIZE		0x0F
33 #define MMS114_INFOMATION		0x10
34 #define MMS114_TSP_REV			0xF0
35 
36 /* Minimum delay time is 50us between stop and start signal of i2c */
37 #define MMS114_I2C_DELAY		50
38 
39 /* 200ms needs after power on */
40 #define MMS114_POWERON_DELAY		200
41 
42 /* Touchscreen absolute values */
43 #define MMS114_MAX_AREA			0xff
44 
45 #define MMS114_MAX_TOUCH		10
46 #define MMS114_PACKET_NUM		8
47 
48 /* Touch type */
49 #define MMS114_TYPE_NONE		0
50 #define MMS114_TYPE_TOUCHSCREEN		1
51 #define MMS114_TYPE_TOUCHKEY		2
52 
53 struct mms114_data {
54 	struct i2c_client	*client;
55 	struct input_dev	*input_dev;
56 	struct regulator	*core_reg;
57 	struct regulator	*io_reg;
58 	const struct mms114_platform_data	*pdata;
59 
60 	/* Use cache data for mode control register(write only) */
61 	u8			cache_mode_control;
62 };
63 
64 struct mms114_touch {
65 	u8 id:4, reserved_bit4:1, type:2, pressed:1;
66 	u8 x_hi:4, y_hi:4;
67 	u8 x_lo;
68 	u8 y_lo;
69 	u8 width;
70 	u8 strength;
71 	u8 reserved[2];
72 } __packed;
73 
74 static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
75 			     unsigned int len, u8 *val)
76 {
77 	struct i2c_client *client = data->client;
78 	struct i2c_msg xfer[2];
79 	u8 buf = reg & 0xff;
80 	int error;
81 
82 	if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
83 		BUG();
84 
85 	/* Write register: use repeated start */
86 	xfer[0].addr = client->addr;
87 	xfer[0].flags = I2C_M_TEN | I2C_M_NOSTART;
88 	xfer[0].len = 1;
89 	xfer[0].buf = &buf;
90 
91 	/* Read data */
92 	xfer[1].addr = client->addr;
93 	xfer[1].flags = I2C_M_RD;
94 	xfer[1].len = len;
95 	xfer[1].buf = val;
96 
97 	error = i2c_transfer(client->adapter, xfer, 2);
98 	if (error != 2) {
99 		dev_err(&client->dev,
100 			"%s: i2c transfer failed (%d)\n", __func__, error);
101 		return error < 0 ? error : -EIO;
102 	}
103 	udelay(MMS114_I2C_DELAY);
104 
105 	return 0;
106 }
107 
108 static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
109 {
110 	u8 val;
111 	int error;
112 
113 	if (reg == MMS114_MODE_CONTROL)
114 		return data->cache_mode_control;
115 
116 	error = __mms114_read_reg(data, reg, 1, &val);
117 	return error < 0 ? error : val;
118 }
119 
120 static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
121 			    unsigned int val)
122 {
123 	struct i2c_client *client = data->client;
124 	u8 buf[2];
125 	int error;
126 
127 	buf[0] = reg & 0xff;
128 	buf[1] = val & 0xff;
129 
130 	error = i2c_master_send(client, buf, 2);
131 	if (error != 2) {
132 		dev_err(&client->dev,
133 			"%s: i2c send failed (%d)\n", __func__, error);
134 		return error < 0 ? error : -EIO;
135 	}
136 	udelay(MMS114_I2C_DELAY);
137 
138 	if (reg == MMS114_MODE_CONTROL)
139 		data->cache_mode_control = val;
140 
141 	return 0;
142 }
143 
144 static void mms114_process_mt(struct mms114_data *data, struct mms114_touch *touch)
145 {
146 	const struct mms114_platform_data *pdata = data->pdata;
147 	struct i2c_client *client = data->client;
148 	struct input_dev *input_dev = data->input_dev;
149 	unsigned int id;
150 	unsigned int x;
151 	unsigned int y;
152 
153 	if (touch->id > MMS114_MAX_TOUCH) {
154 		dev_err(&client->dev, "Wrong touch id (%d)\n", touch->id);
155 		return;
156 	}
157 
158 	if (touch->type != MMS114_TYPE_TOUCHSCREEN) {
159 		dev_err(&client->dev, "Wrong touch type (%d)\n", touch->type);
160 		return;
161 	}
162 
163 	id = touch->id - 1;
164 	x = touch->x_lo | touch->x_hi << 8;
165 	y = touch->y_lo | touch->y_hi << 8;
166 	if (x > pdata->x_size || y > pdata->y_size) {
167 		dev_dbg(&client->dev,
168 			"Wrong touch coordinates (%d, %d)\n", x, y);
169 		return;
170 	}
171 
172 	if (pdata->x_invert)
173 		x = pdata->x_size - x;
174 	if (pdata->y_invert)
175 		y = pdata->y_size - y;
176 
177 	dev_dbg(&client->dev,
178 		"id: %d, type: %d, pressed: %d, x: %d, y: %d, width: %d, strength: %d\n",
179 		id, touch->type, touch->pressed,
180 		x, y, touch->width, touch->strength);
181 
182 	input_mt_slot(input_dev, id);
183 	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, touch->pressed);
184 
185 	if (touch->pressed) {
186 		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, touch->width);
187 		input_report_abs(input_dev, ABS_MT_POSITION_X, x);
188 		input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
189 		input_report_abs(input_dev, ABS_MT_PRESSURE, touch->strength);
190 	}
191 }
192 
193 static irqreturn_t mms114_interrupt(int irq, void *dev_id)
194 {
195 	struct mms114_data *data = dev_id;
196 	struct input_dev *input_dev = data->input_dev;
197 	struct mms114_touch touch[MMS114_MAX_TOUCH];
198 	int packet_size;
199 	int touch_size;
200 	int index;
201 	int error;
202 
203 	mutex_lock(&input_dev->mutex);
204 	if (!input_dev->users) {
205 		mutex_unlock(&input_dev->mutex);
206 		goto out;
207 	}
208 	mutex_unlock(&input_dev->mutex);
209 
210 	packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
211 	if (packet_size <= 0)
212 		goto out;
213 
214 	touch_size = packet_size / MMS114_PACKET_NUM;
215 
216 	error = __mms114_read_reg(data, MMS114_INFOMATION, packet_size,
217 			(u8 *)touch);
218 	if (error < 0)
219 		goto out;
220 
221 	for (index = 0; index < touch_size; index++)
222 		mms114_process_mt(data, touch + index);
223 
224 	input_mt_report_pointer_emulation(data->input_dev, true);
225 	input_sync(data->input_dev);
226 
227 out:
228 	return IRQ_HANDLED;
229 }
230 
231 static int mms114_set_active(struct mms114_data *data, bool active)
232 {
233 	int val;
234 
235 	val = mms114_read_reg(data, MMS114_MODE_CONTROL);
236 	if (val < 0)
237 		return val;
238 
239 	val &= ~MMS114_OPERATION_MODE_MASK;
240 
241 	/* If active is false, sleep mode */
242 	if (active)
243 		val |= MMS114_ACTIVE;
244 
245 	return mms114_write_reg(data, MMS114_MODE_CONTROL, val);
246 }
247 
248 static int mms114_get_version(struct mms114_data *data)
249 {
250 	struct device *dev = &data->client->dev;
251 	u8 buf[6];
252 	int error;
253 
254 	error = __mms114_read_reg(data, MMS114_TSP_REV, 6, buf);
255 	if (error < 0)
256 		return error;
257 
258 	dev_info(dev, "TSP Rev: 0x%x, HW Rev: 0x%x, Firmware Ver: 0x%x\n",
259 		 buf[0], buf[1], buf[3]);
260 
261 	return 0;
262 }
263 
264 static int mms114_setup_regs(struct mms114_data *data)
265 {
266 	const struct mms114_platform_data *pdata = data->pdata;
267 	int val;
268 	int error;
269 
270 	error = mms114_get_version(data);
271 	if (error < 0)
272 		return error;
273 
274 	error = mms114_set_active(data, true);
275 	if (error < 0)
276 		return error;
277 
278 	val = (pdata->x_size >> 8) & 0xf;
279 	val |= ((pdata->y_size >> 8) & 0xf) << 4;
280 	error = mms114_write_reg(data, MMS114_XY_RESOLUTION_H, val);
281 	if (error < 0)
282 		return error;
283 
284 	val = pdata->x_size & 0xff;
285 	error = mms114_write_reg(data, MMS114_X_RESOLUTION, val);
286 	if (error < 0)
287 		return error;
288 
289 	val = pdata->y_size & 0xff;
290 	error = mms114_write_reg(data, MMS114_Y_RESOLUTION, val);
291 	if (error < 0)
292 		return error;
293 
294 	if (pdata->contact_threshold) {
295 		error = mms114_write_reg(data, MMS114_CONTACT_THRESHOLD,
296 				pdata->contact_threshold);
297 		if (error < 0)
298 			return error;
299 	}
300 
301 	if (pdata->moving_threshold) {
302 		error = mms114_write_reg(data, MMS114_MOVING_THRESHOLD,
303 				pdata->moving_threshold);
304 		if (error < 0)
305 			return error;
306 	}
307 
308 	return 0;
309 }
310 
311 static int mms114_start(struct mms114_data *data)
312 {
313 	struct i2c_client *client = data->client;
314 	int error;
315 
316 	error = regulator_enable(data->core_reg);
317 	if (error) {
318 		dev_err(&client->dev, "Failed to enable avdd: %d\n", error);
319 		return error;
320 	}
321 
322 	error = regulator_enable(data->io_reg);
323 	if (error) {
324 		dev_err(&client->dev, "Failed to enable vdd: %d\n", error);
325 		regulator_disable(data->core_reg);
326 		return error;
327 	}
328 
329 	mdelay(MMS114_POWERON_DELAY);
330 
331 	error = mms114_setup_regs(data);
332 	if (error < 0) {
333 		regulator_disable(data->io_reg);
334 		regulator_disable(data->core_reg);
335 		return error;
336 	}
337 
338 	if (data->pdata->cfg_pin)
339 		data->pdata->cfg_pin(true);
340 
341 	enable_irq(client->irq);
342 
343 	return 0;
344 }
345 
346 static void mms114_stop(struct mms114_data *data)
347 {
348 	struct i2c_client *client = data->client;
349 	int error;
350 
351 	disable_irq(client->irq);
352 
353 	if (data->pdata->cfg_pin)
354 		data->pdata->cfg_pin(false);
355 
356 	error = regulator_disable(data->io_reg);
357 	if (error)
358 		dev_warn(&client->dev, "Failed to disable vdd: %d\n", error);
359 
360 	error = regulator_disable(data->core_reg);
361 	if (error)
362 		dev_warn(&client->dev, "Failed to disable avdd: %d\n", error);
363 }
364 
365 static int mms114_input_open(struct input_dev *dev)
366 {
367 	struct mms114_data *data = input_get_drvdata(dev);
368 
369 	return mms114_start(data);
370 }
371 
372 static void mms114_input_close(struct input_dev *dev)
373 {
374 	struct mms114_data *data = input_get_drvdata(dev);
375 
376 	mms114_stop(data);
377 }
378 
379 #ifdef CONFIG_OF
380 static struct mms114_platform_data *mms114_parse_dt(struct device *dev)
381 {
382 	struct mms114_platform_data *pdata;
383 	struct device_node *np = dev->of_node;
384 
385 	if (!np)
386 		return NULL;
387 
388 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
389 	if (!pdata) {
390 		dev_err(dev, "failed to allocate platform data\n");
391 		return NULL;
392 	}
393 
394 	if (of_property_read_u32(np, "x-size", &pdata->x_size)) {
395 		dev_err(dev, "failed to get x-size property\n");
396 		return NULL;
397 	};
398 
399 	if (of_property_read_u32(np, "y-size", &pdata->y_size)) {
400 		dev_err(dev, "failed to get y-size property\n");
401 		return NULL;
402 	};
403 
404 	of_property_read_u32(np, "contact-threshold",
405 				&pdata->contact_threshold);
406 	of_property_read_u32(np, "moving-threshold",
407 				&pdata->moving_threshold);
408 
409 	if (of_find_property(np, "x-invert", NULL))
410 		pdata->x_invert = true;
411 	if (of_find_property(np, "y-invert", NULL))
412 		pdata->y_invert = true;
413 
414 	return pdata;
415 }
416 #else
417 static inline struct mms114_platform_data *mms114_parse_dt(struct device *dev)
418 {
419 	return NULL;
420 }
421 #endif
422 
423 static int mms114_probe(struct i2c_client *client,
424 				  const struct i2c_device_id *id)
425 {
426 	const struct mms114_platform_data *pdata;
427 	struct mms114_data *data;
428 	struct input_dev *input_dev;
429 	int error;
430 
431 	pdata = dev_get_platdata(&client->dev);
432 	if (!pdata)
433 		pdata = mms114_parse_dt(&client->dev);
434 
435 	if (!pdata) {
436 		dev_err(&client->dev, "Need platform data\n");
437 		return -EINVAL;
438 	}
439 
440 	if (!i2c_check_functionality(client->adapter,
441 				I2C_FUNC_PROTOCOL_MANGLING)) {
442 		dev_err(&client->dev,
443 			"Need i2c bus that supports protocol mangling\n");
444 		return -ENODEV;
445 	}
446 
447 	data = devm_kzalloc(&client->dev, sizeof(struct mms114_data),
448 			    GFP_KERNEL);
449 	input_dev = devm_input_allocate_device(&client->dev);
450 	if (!data || !input_dev) {
451 		dev_err(&client->dev, "Failed to allocate memory\n");
452 		return -ENOMEM;
453 	}
454 
455 	data->client = client;
456 	data->input_dev = input_dev;
457 	data->pdata = pdata;
458 
459 	input_dev->name = "MELFAS MMS114 Touchscreen";
460 	input_dev->id.bustype = BUS_I2C;
461 	input_dev->dev.parent = &client->dev;
462 	input_dev->open = mms114_input_open;
463 	input_dev->close = mms114_input_close;
464 
465 	__set_bit(EV_ABS, input_dev->evbit);
466 	__set_bit(EV_KEY, input_dev->evbit);
467 	__set_bit(BTN_TOUCH, input_dev->keybit);
468 	input_set_abs_params(input_dev, ABS_X, 0, data->pdata->x_size, 0, 0);
469 	input_set_abs_params(input_dev, ABS_Y, 0, data->pdata->y_size, 0, 0);
470 
471 	/* For multi touch */
472 	input_mt_init_slots(input_dev, MMS114_MAX_TOUCH, 0);
473 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
474 			     0, MMS114_MAX_AREA, 0, 0);
475 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
476 			     0, data->pdata->x_size, 0, 0);
477 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
478 			     0, data->pdata->y_size, 0, 0);
479 	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
480 
481 	input_set_drvdata(input_dev, data);
482 	i2c_set_clientdata(client, data);
483 
484 	data->core_reg = devm_regulator_get(&client->dev, "avdd");
485 	if (IS_ERR(data->core_reg)) {
486 		error = PTR_ERR(data->core_reg);
487 		dev_err(&client->dev,
488 			"Unable to get the Core regulator (%d)\n", error);
489 		return error;
490 	}
491 
492 	data->io_reg = devm_regulator_get(&client->dev, "vdd");
493 	if (IS_ERR(data->io_reg)) {
494 		error = PTR_ERR(data->io_reg);
495 		dev_err(&client->dev,
496 			"Unable to get the IO regulator (%d)\n", error);
497 		return error;
498 	}
499 
500 	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
501 			mms114_interrupt, IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
502 			dev_name(&client->dev), data);
503 	if (error) {
504 		dev_err(&client->dev, "Failed to register interrupt\n");
505 		return error;
506 	}
507 	disable_irq(client->irq);
508 
509 	error = input_register_device(data->input_dev);
510 	if (error) {
511 		dev_err(&client->dev, "Failed to register input device\n");
512 		return error;
513 	}
514 
515 	return 0;
516 }
517 
518 static int __maybe_unused mms114_suspend(struct device *dev)
519 {
520 	struct i2c_client *client = to_i2c_client(dev);
521 	struct mms114_data *data = i2c_get_clientdata(client);
522 	struct input_dev *input_dev = data->input_dev;
523 	int id;
524 
525 	/* Release all touch */
526 	for (id = 0; id < MMS114_MAX_TOUCH; id++) {
527 		input_mt_slot(input_dev, id);
528 		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
529 	}
530 
531 	input_mt_report_pointer_emulation(input_dev, true);
532 	input_sync(input_dev);
533 
534 	mutex_lock(&input_dev->mutex);
535 	if (input_dev->users)
536 		mms114_stop(data);
537 	mutex_unlock(&input_dev->mutex);
538 
539 	return 0;
540 }
541 
542 static int __maybe_unused mms114_resume(struct device *dev)
543 {
544 	struct i2c_client *client = to_i2c_client(dev);
545 	struct mms114_data *data = i2c_get_clientdata(client);
546 	struct input_dev *input_dev = data->input_dev;
547 	int error;
548 
549 	mutex_lock(&input_dev->mutex);
550 	if (input_dev->users) {
551 		error = mms114_start(data);
552 		if (error < 0) {
553 			mutex_unlock(&input_dev->mutex);
554 			return error;
555 		}
556 	}
557 	mutex_unlock(&input_dev->mutex);
558 
559 	return 0;
560 }
561 
562 static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);
563 
564 static const struct i2c_device_id mms114_id[] = {
565 	{ "mms114", 0 },
566 	{ }
567 };
568 MODULE_DEVICE_TABLE(i2c, mms114_id);
569 
570 #ifdef CONFIG_OF
571 static const struct of_device_id mms114_dt_match[] = {
572 	{ .compatible = "melfas,mms114" },
573 	{ }
574 };
575 #endif
576 
577 static struct i2c_driver mms114_driver = {
578 	.driver = {
579 		.name	= "mms114",
580 		.owner	= THIS_MODULE,
581 		.pm	= &mms114_pm_ops,
582 		.of_match_table = of_match_ptr(mms114_dt_match),
583 	},
584 	.probe		= mms114_probe,
585 	.id_table	= mms114_id,
586 };
587 
588 module_i2c_driver(mms114_driver);
589 
590 /* Module information */
591 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
592 MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
593 MODULE_LICENSE("GPL");
594