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
53struct 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
64struct 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
74static 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
108static 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
120static 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
144static 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
193static 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
227out:
228	return IRQ_HANDLED;
229}
230
231static 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
248static 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
264static 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
311static 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
346static 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
365static 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
372static 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
380static 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
417static inline struct mms114_platform_data *mms114_parse_dt(struct device *dev)
418{
419	return NULL;
420}
421#endif
422
423static 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
518static 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
542static 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
562static SIMPLE_DEV_PM_OPS(mms114_pm_ops, mms114_suspend, mms114_resume);
563
564static const struct i2c_device_id mms114_id[] = {
565	{ "mms114", 0 },
566	{ }
567};
568MODULE_DEVICE_TABLE(i2c, mms114_id);
569
570#ifdef CONFIG_OF
571static const struct of_device_id mms114_dt_match[] = {
572	{ .compatible = "melfas,mms114" },
573	{ }
574};
575#endif
576
577static 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
588module_i2c_driver(mms114_driver);
589
590/* Module information */
591MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
592MODULE_DESCRIPTION("MELFAS mms114 Touchscreen driver");
593MODULE_LICENSE("GPL");
594