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  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
 54enum mms_type {
 55	TYPE_MMS114	= 114,
 56	TYPE_MMS152	= 152,
 57};
 58
 59struct mms114_data {
 60	struct i2c_client	*client;
 61	struct input_dev	*input_dev;
 62	struct regulator	*core_reg;
 63	struct regulator	*io_reg;
 64	struct touchscreen_properties props;
 65	enum mms_type		type;
 66	unsigned int		contact_threshold;
 67	unsigned int		moving_threshold;
 68
 69	/* Use cache data for mode control register(write only) */
 70	u8			cache_mode_control;
 71};
 72
 73struct mms114_touch {
 74	u8 id:4, reserved_bit4:1, type:2, pressed:1;
 75	u8 x_hi:4, y_hi:4;
 76	u8 x_lo;
 77	u8 y_lo;
 78	u8 width;
 79	u8 strength;
 80	u8 reserved[2];
 81} __packed;
 82
 83static int __mms114_read_reg(struct mms114_data *data, unsigned int reg,
 84			     unsigned int len, u8 *val)
 85{
 86	struct i2c_client *client = data->client;
 87	struct i2c_msg xfer[2];
 88	u8 buf = reg & 0xff;
 89	int error;
 90
 91	if (reg <= MMS114_MODE_CONTROL && reg + len > MMS114_MODE_CONTROL)
 92		BUG();
 93
 94	/* Write register: use repeated start */
 95	xfer[0].addr = client->addr;
 96	xfer[0].flags = I2C_M_TEN | I2C_M_NOSTART;
 97	xfer[0].len = 1;
 98	xfer[0].buf = &buf;
 99
100	/* Read data */
101	xfer[1].addr = client->addr;
102	xfer[1].flags = I2C_M_RD;
103	xfer[1].len = len;
104	xfer[1].buf = val;
105
106	error = i2c_transfer(client->adapter, xfer, 2);
107	if (error != 2) {
108		dev_err(&client->dev,
109			"%s: i2c transfer failed (%d)\n", __func__, error);
110		return error < 0 ? error : -EIO;
111	}
112	udelay(MMS114_I2C_DELAY);
113
114	return 0;
115}
116
117static int mms114_read_reg(struct mms114_data *data, unsigned int reg)
118{
119	u8 val;
120	int error;
121
122	if (reg == MMS114_MODE_CONTROL)
123		return data->cache_mode_control;
124
125	error = __mms114_read_reg(data, reg, 1, &val);
126	return error < 0 ? error : val;
127}
128
129static int mms114_write_reg(struct mms114_data *data, unsigned int reg,
130			    unsigned int val)
131{
132	struct i2c_client *client = data->client;
133	u8 buf[2];
134	int error;
135
136	buf[0] = reg & 0xff;
137	buf[1] = val & 0xff;
138
139	error = i2c_master_send(client, buf, 2);
140	if (error != 2) {
141		dev_err(&client->dev,
142			"%s: i2c send failed (%d)\n", __func__, error);
143		return error < 0 ? error : -EIO;
144	}
145	udelay(MMS114_I2C_DELAY);
146
147	if (reg == MMS114_MODE_CONTROL)
148		data->cache_mode_control = val;
149
150	return 0;
151}
152
153static void mms114_process_mt(struct mms114_data *data, struct mms114_touch *touch)
154{
155	struct i2c_client *client = data->client;
156	struct input_dev *input_dev = data->input_dev;
157	unsigned int id;
158	unsigned int x;
159	unsigned int y;
160
161	if (touch->id > MMS114_MAX_TOUCH) {
162		dev_err(&client->dev, "Wrong touch id (%d)\n", touch->id);
163		return;
164	}
165
166	if (touch->type != MMS114_TYPE_TOUCHSCREEN) {
167		dev_err(&client->dev, "Wrong touch type (%d)\n", touch->type);
168		return;
169	}
170
171	id = touch->id - 1;
172	x = touch->x_lo | touch->x_hi << 8;
173	y = touch->y_lo | touch->y_hi << 8;
174
175	dev_dbg(&client->dev,
176		"id: %d, type: %d, pressed: %d, x: %d, y: %d, width: %d, strength: %d\n",
177		id, touch->type, touch->pressed,
178		x, y, touch->width, touch->strength);
179
180	input_mt_slot(input_dev, id);
181	input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, touch->pressed);
182
183	if (touch->pressed) {
184		touchscreen_report_pos(input_dev, &data->props, x, y, true);
185		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, touch->width);
186		input_report_abs(input_dev, ABS_MT_PRESSURE, touch->strength);
187	}
188}
189
190static irqreturn_t mms114_interrupt(int irq, void *dev_id)
191{
192	struct mms114_data *data = dev_id;
193	struct input_dev *input_dev = data->input_dev;
194	struct mms114_touch touch[MMS114_MAX_TOUCH];
195	int packet_size;
196	int touch_size;
197	int index;
198	int error;
199
200	mutex_lock(&input_dev->mutex);
201	if (!input_dev->users) {
202		mutex_unlock(&input_dev->mutex);
203		goto out;
204	}
205	mutex_unlock(&input_dev->mutex);
206
207	packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
208	if (packet_size <= 0)
209		goto out;
210
211	touch_size = packet_size / MMS114_PACKET_NUM;
212
213	error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size,
214			(u8 *)touch);
215	if (error < 0)
216		goto out;
217
218	for (index = 0; index < touch_size; index++)
219		mms114_process_mt(data, touch + index);
220
221	input_mt_report_pointer_emulation(data->input_dev, true);
222	input_sync(data->input_dev);
223
224out:
225	return IRQ_HANDLED;
226}
227
228static int mms114_set_active(struct mms114_data *data, bool active)
229{
230	int val;
231
232	val = mms114_read_reg(data, MMS114_MODE_CONTROL);
233	if (val < 0)
234		return val;
235
236	val &= ~MMS114_OPERATION_MODE_MASK;
237
238	/* If active is false, sleep mode */
239	if (active)
240		val |= MMS114_ACTIVE;
241
242	return mms114_write_reg(data, MMS114_MODE_CONTROL, val);
243}
244
245static int mms114_get_version(struct mms114_data *data)
246{
247	struct device *dev = &data->client->dev;
248	u8 buf[6];
249	int group;
250	int error;
251
252	switch (data->type) {
253	case TYPE_MMS152:
254		error = __mms114_read_reg(data, MMS152_FW_REV, 3, buf);
255		if (error)
256			return error;
257
258		group = i2c_smbus_read_byte_data(data->client,
259						  MMS152_COMPAT_GROUP);
260		if (group < 0)
261			return group;
262
263		dev_info(dev, "TSP FW Rev: bootloader 0x%x / core 0x%x / config 0x%x, Compat group: %c\n",
264			 buf[0], buf[1], buf[2], group);
265		break;
266
267	case TYPE_MMS114:
268		error = __mms114_read_reg(data, MMS114_TSP_REV, 6, buf);
269		if (error)
270			return error;
271
272		dev_info(dev, "TSP Rev: 0x%x, HW Rev: 0x%x, Firmware Ver: 0x%x\n",
273			 buf[0], buf[1], buf[3]);
274		break;
275	}
276
277	return 0;
278}
279
280static int mms114_setup_regs(struct mms114_data *data)
281{
282	const struct touchscreen_properties *props = &data->props;
283	int val;
284	int error;
285
286	error = mms114_get_version(data);
287	if (error < 0)
288		return error;
289
290	/* MMS152 has no configuration or power on registers */
291	if (data->type == TYPE_MMS152)
292		return 0;
293
294	error = mms114_set_active(data, true);
295	if (error < 0)
296		return error;
297
298	val = (props->max_x >> 8) & 0xf;
299	val |= ((props->max_y >> 8) & 0xf) << 4;
300	error = mms114_write_reg(data, MMS114_XY_RESOLUTION_H, val);
301	if (error < 0)
302		return error;
303
304	val = props->max_x & 0xff;
305	error = mms114_write_reg(data, MMS114_X_RESOLUTION, val);
306	if (error < 0)
307		return error;
308
309	val = props->max_x & 0xff;
310	error = mms114_write_reg(data, MMS114_Y_RESOLUTION, val);
311	if (error < 0)
312		return error;
313
314	if (data->contact_threshold) {
315		error = mms114_write_reg(data, MMS114_CONTACT_THRESHOLD,
316				data->contact_threshold);
317		if (error < 0)
318			return error;
319	}
320
321	if (data->moving_threshold) {
322		error = mms114_write_reg(data, MMS114_MOVING_THRESHOLD,
323				data->moving_threshold);
324		if (error < 0)
325			return error;
326	}
327
328	return 0;
329}
330
331static int mms114_start(struct mms114_data *data)
332{
333	struct i2c_client *client = data->client;
334	int error;
335
336	error = regulator_enable(data->core_reg);
337	if (error) {
338		dev_err(&client->dev, "Failed to enable avdd: %d\n", error);
339		return error;
340	}
341
342	error = regulator_enable(data->io_reg);
343	if (error) {
344		dev_err(&client->dev, "Failed to enable vdd: %d\n", error);
345		regulator_disable(data->core_reg);
346		return error;
347	}
348
349	msleep(MMS114_POWERON_DELAY);
350
351	error = mms114_setup_regs(data);
352	if (error < 0) {
353		regulator_disable(data->io_reg);
354		regulator_disable(data->core_reg);
355		return error;
356	}
357
358	enable_irq(client->irq);
359
360	return 0;
361}
362
363static void mms114_stop(struct mms114_data *data)
364{
365	struct i2c_client *client = data->client;
366	int error;
367
368	disable_irq(client->irq);
369
370	error = regulator_disable(data->io_reg);
371	if (error)
372		dev_warn(&client->dev, "Failed to disable vdd: %d\n", error);
373
374	error = regulator_disable(data->core_reg);
375	if (error)
376		dev_warn(&client->dev, "Failed to disable avdd: %d\n", error);
377}
378
379static int mms114_input_open(struct input_dev *dev)
380{
381	struct mms114_data *data = input_get_drvdata(dev);
382
383	return mms114_start(data);
384}
385
386static void mms114_input_close(struct input_dev *dev)
387{
388	struct mms114_data *data = input_get_drvdata(dev);
389
390	mms114_stop(data);
391}
392
393static int mms114_parse_legacy_bindings(struct mms114_data *data)
394{
395	struct device *dev = &data->client->dev;
396	struct touchscreen_properties *props = &data->props;
397
398	if (device_property_read_u32(dev, "x-size", &props->max_x)) {
399		dev_dbg(dev, "failed to get legacy x-size property\n");
400		return -EINVAL;
401	}
402
403	if (device_property_read_u32(dev, "y-size", &props->max_y)) {
404		dev_dbg(dev, "failed to get legacy y-size property\n");
405		return -EINVAL;
406	}
407
408	device_property_read_u32(dev, "contact-threshold",
409				&data->contact_threshold);
410	device_property_read_u32(dev, "moving-threshold",
411				&data->moving_threshold);
412
413	if (device_property_read_bool(dev, "x-invert"))
414		props->invert_x = true;
415	if (device_property_read_bool(dev, "y-invert"))
416		props->invert_y = true;
417
418	props->swap_x_y = false;
419
420	return 0;
421}
422
423static int mms114_probe(struct i2c_client *client,
424				  const struct i2c_device_id *id)
425{
426	struct mms114_data *data;
427	struct input_dev *input_dev;
428	const void *match_data;
429	int error;
430
431	if (!i2c_check_functionality(client->adapter,
432				I2C_FUNC_PROTOCOL_MANGLING)) {
433		dev_err(&client->dev,
434			"Need i2c bus that supports protocol mangling\n");
435		return -ENODEV;
436	}
437
438	data = devm_kzalloc(&client->dev, sizeof(struct mms114_data),
439			    GFP_KERNEL);
440	input_dev = devm_input_allocate_device(&client->dev);
441	if (!data || !input_dev) {
442		dev_err(&client->dev, "Failed to allocate memory\n");
443		return -ENOMEM;
444	}
445
446	data->client = client;
447	data->input_dev = input_dev;
448
449	/* FIXME: switch to device_get_match_data() when available */
450	match_data = of_device_get_match_data(&client->dev);
451	if (!match_data)
452		return -EINVAL;
453
454	data->type = (enum mms_type)match_data;
455
456	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
457	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
458	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
459	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
460			     0, MMS114_MAX_AREA, 0, 0);
461
462	touchscreen_parse_properties(input_dev, true, &data->props);
463	if (!data->props.max_x || !data->props.max_y) {
464		dev_dbg(&client->dev,
465			"missing X/Y size properties, trying legacy bindings\n");
466		error = mms114_parse_legacy_bindings(data);
467		if (error)
468			return error;
469
470		input_set_abs_params(input_dev, ABS_MT_POSITION_X,
471				     0, data->props.max_x, 0, 0);
472		input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
473				     0, data->props.max_y, 0, 0);
474	}
475
476	if (data->type == TYPE_MMS114) {
477		/*
478		 * The firmware handles movement and pressure fuzz, so
479		 * don't duplicate that in software.
480		 */
481		data->moving_threshold = input_abs_get_fuzz(input_dev,
482							    ABS_MT_POSITION_X);
483		data->contact_threshold = input_abs_get_fuzz(input_dev,
484							     ABS_MT_PRESSURE);
485		input_abs_set_fuzz(input_dev, ABS_MT_POSITION_X, 0);
486		input_abs_set_fuzz(input_dev, ABS_MT_POSITION_Y, 0);
487		input_abs_set_fuzz(input_dev, ABS_MT_PRESSURE, 0);
488	}
489
490	input_dev->name = devm_kasprintf(&client->dev, GFP_KERNEL,
491					 "MELFAS MMS%d Touchscreen",
492					 data->type);
493	if (!input_dev->name)
494		return -ENOMEM;
495
496	input_dev->id.bustype = BUS_I2C;
497	input_dev->dev.parent = &client->dev;
498	input_dev->open = mms114_input_open;
499	input_dev->close = mms114_input_close;
500
501	error = input_mt_init_slots(input_dev, MMS114_MAX_TOUCH,
502				    INPUT_MT_DIRECT);
503	if (error)
504		return error;
505
506	input_set_drvdata(input_dev, data);
507	i2c_set_clientdata(client, data);
508
509	data->core_reg = devm_regulator_get(&client->dev, "avdd");
510	if (IS_ERR(data->core_reg)) {
511		error = PTR_ERR(data->core_reg);
512		dev_err(&client->dev,
513			"Unable to get the Core regulator (%d)\n", error);
514		return error;
515	}
516
517	data->io_reg = devm_regulator_get(&client->dev, "vdd");
518	if (IS_ERR(data->io_reg)) {
519		error = PTR_ERR(data->io_reg);
520		dev_err(&client->dev,
521			"Unable to get the IO regulator (%d)\n", error);
522		return error;
523	}
524
525	error = devm_request_threaded_irq(&client->dev, client->irq,
526					  NULL, mms114_interrupt, IRQF_ONESHOT,
527					  dev_name(&client->dev), data);
528	if (error) {
529		dev_err(&client->dev, "Failed to register interrupt\n");
530		return error;
531	}
532	disable_irq(client->irq);
533
534	error = input_register_device(data->input_dev);
535	if (error) {
536		dev_err(&client->dev, "Failed to register input device\n");
537		return error;
538	}
539
540	return 0;
541}
542
543static int __maybe_unused mms114_suspend(struct device *dev)
544{
545	struct i2c_client *client = to_i2c_client(dev);
546	struct mms114_data *data = i2c_get_clientdata(client);
547	struct input_dev *input_dev = data->input_dev;
548	int id;
549
550	/* Release all touch */
551	for (id = 0; id < MMS114_MAX_TOUCH; id++) {
552		input_mt_slot(input_dev, id);
553		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
554	}
555
556	input_mt_report_pointer_emulation(input_dev, true);
557	input_sync(input_dev);
558
559	mutex_lock(&input_dev->mutex);
560	if (input_dev->users)
561		mms114_stop(data);
562	mutex_unlock(&input_dev->mutex);
563
564	return 0;
565}
566
567static int __maybe_unused mms114_resume(struct device *dev)
568{
569	struct i2c_client *client = to_i2c_client(dev);
570	struct mms114_data *data = i2c_get_clientdata(client);
571	struct input_dev *input_dev = data->input_dev;
572	int error;
573
574	mutex_lock(&input_dev->mutex);
575	if (input_dev->users) {
576		error = mms114_start(data);
577		if (error < 0) {
578			mutex_unlock(&input_dev->mutex);
579			return error;
580		}
581	}
582	mutex_unlock(&input_dev->mutex);
583
584	return 0;
585}
586
587static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);
588
589static const struct i2c_device_id mms114_id[] = {
590	{ "mms114", 0 },
591	{ }
592};
593MODULE_DEVICE_TABLE(i2c, mms114_id);
594
595#ifdef CONFIG_OF
596static const struct of_device_id mms114_dt_match[] = {
597	{
598		.compatible = "melfas,mms114",
599		.data = (void *)TYPE_MMS114,
600	}, {
601		.compatible = "melfas,mms152",
602		.data = (void *)TYPE_MMS152,
603	},
604	{ }
605};
606MODULE_DEVICE_TABLE(of, mms114_dt_match);
607#endif
608
609static struct i2c_driver mms114_driver = {
610	.driver = {
611		.name	= "mms114",
612		.pm	= &mms114_pm_ops,
613		.of_match_table = of_match_ptr(mms114_dt_match),
614	},
615	.probe		= mms114_probe,
616	.id_table	= mms114_id,
617};
618
619module_i2c_driver(mms114_driver);
620
621/* Module information */
622MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
623MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
624MODULE_LICENSE("GPL v2");