1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for Semtech SX8654 I2C touchscreen controller.
4 *
5 * Copyright (c) 2015 Armadeus Systems
6 *	S��bastien Szymanski <sebastien.szymanski@armadeus.com>
7 *
8 * Using code from:
9 *  - sx865x.c
10 *	Copyright (c) 2013 U-MoBo Srl
11 *	Pierluigi Passaro <p.passaro@u-mobo.com>
12 *  - sx8650.c
13 *      Copyright (c) 2009 Wayne Roberts
14 *  - tsc2007.c
15 *      Copyright (c) 2008 Kwangwoo Lee
16 *  - ads7846.c
17 *      Copyright (c) 2005 David Brownell
18 *      Copyright (c) 2006 Nokia Corporation
19 *  - corgi_ts.c
20 *      Copyright (C) 2004-2005 Richard Purdie
21 *  - omap_ts.[hc], ads7846.h, ts_osk.c
22 *      Copyright (C) 2002 MontaVista Software
23 *      Copyright (C) 2004 Texas Instruments
24 *      Copyright (C) 2005 Dirk Behme
25 */
26
27#include <linux/bitops.h>
28#include <linux/delay.h>
29#include <linux/gpio/consumer.h>
30#include <linux/i2c.h>
31#include <linux/input.h>
32#include <linux/input/touchscreen.h>
33#include <linux/interrupt.h>
34#include <linux/irq.h>
35#include <linux/module.h>
36#include <linux/of.h>
37
38/* register addresses */
39#define I2C_REG_TOUCH0			0x00
40#define I2C_REG_TOUCH1			0x01
41#define I2C_REG_CHANMASK		0x04
42#define I2C_REG_IRQMASK			0x22
43#define I2C_REG_IRQSRC			0x23
44#define I2C_REG_SOFTRESET		0x3f
45
46#define I2C_REG_SX8650_STAT		0x05
47#define SX8650_STAT_CONVIRQ		BIT(7)
48
49/* commands */
50#define CMD_READ_REGISTER		0x40
51#define CMD_PENTRG			0xe0
52
53/* value for I2C_REG_SOFTRESET */
54#define SOFTRESET_VALUE			0xde
55
56/* bits for I2C_REG_IRQSRC */
57#define IRQ_PENTOUCH_TOUCHCONVDONE	BIT(3)
58#define IRQ_PENRELEASE			BIT(2)
59
60/* bits for RegTouch1 */
61#define CONDIRQ				0x20
62#define RPDNT_100K			0x00
63#define FILT_7SA			0x03
64
65/* bits for I2C_REG_CHANMASK */
66#define CONV_X				BIT(7)
67#define CONV_Y				BIT(6)
68
69/* coordinates rate: higher nibble of CTRL0 register */
70#define RATE_MANUAL			0x00
71#define RATE_5000CPS			0xf0
72
73/* power delay: lower nibble of CTRL0 register */
74#define POWDLY_1_1MS			0x0b
75
76/* for sx8650, as we have no pen release IRQ there: timeout in ns following the
77 * last PENIRQ after which we assume the pen is lifted.
78 */
79#define SX8650_PENIRQ_TIMEOUT		msecs_to_jiffies(10)
80
81#define MAX_12BIT			((1 << 12) - 1)
82#define MAX_I2C_READ_LEN		10 /* see datasheet section 5.1.5 */
83
84/* channel definition */
85#define CH_X				0x00
86#define CH_Y				0x01
87
88struct sx865x_data {
89	u8 cmd_manual;
90	u8 chan_mask;
91	bool has_irq_penrelease;
92	bool has_reg_irqmask;
93	irq_handler_t irqh;
94};
95
96struct sx8654 {
97	struct input_dev *input;
98	struct i2c_client *client;
99	struct gpio_desc *gpio_reset;
100
101	spinlock_t lock;	/* for input reporting from irq/timer */
102	struct timer_list timer;
103
104	struct touchscreen_properties props;
105
106	const struct sx865x_data *data;
107};
108
109static inline void sx865x_penrelease(struct sx8654 *ts)
110{
111	struct input_dev *input_dev = ts->input;
112
113	input_report_key(input_dev, BTN_TOUCH, 0);
114	input_sync(input_dev);
115}
116
117static void sx865x_penrelease_timer_handler(struct timer_list *t)
118{
119	struct sx8654 *ts = from_timer(ts, t, timer);
120	unsigned long flags;
121
122	spin_lock_irqsave(&ts->lock, flags);
123	sx865x_penrelease(ts);
124	spin_unlock_irqrestore(&ts->lock, flags);
125	dev_dbg(&ts->client->dev, "penrelease by timer\n");
126}
127
128static irqreturn_t sx8650_irq(int irq, void *handle)
129{
130	struct sx8654 *ts = handle;
131	struct device *dev = &ts->client->dev;
132	int len, i;
133	unsigned long flags;
134	u8 stat;
135	u16 x, y;
136	u16 ch;
137	u16 chdata;
138	__be16 data[MAX_I2C_READ_LEN / sizeof(__be16)];
139	u8 nchan = hweight32(ts->data->chan_mask);
140	u8 readlen = nchan * sizeof(*data);
141
142	stat = i2c_smbus_read_byte_data(ts->client, CMD_READ_REGISTER
143						    | I2C_REG_SX8650_STAT);
144
145	if (!(stat & SX8650_STAT_CONVIRQ)) {
146		dev_dbg(dev, "%s ignore stat [0x%02x]", __func__, stat);
147		return IRQ_HANDLED;
148	}
149
150	len = i2c_master_recv(ts->client, (u8 *)data, readlen);
151	if (len != readlen) {
152		dev_dbg(dev, "ignore short recv (%d)\n", len);
153		return IRQ_HANDLED;
154	}
155
156	spin_lock_irqsave(&ts->lock, flags);
157
158	x = 0;
159	y = 0;
160	for (i = 0; i < nchan; i++) {
161		chdata = be16_to_cpu(data[i]);
162
163		if (unlikely(chdata == 0xFFFF)) {
164			dev_dbg(dev, "invalid qualified data @ %d\n", i);
165			continue;
166		} else if (unlikely(chdata & 0x8000)) {
167			dev_warn(dev, "hibit @ %d [0x%04x]\n", i, chdata);
168			continue;
169		}
170
171		ch = chdata >> 12;
172		if (ch == CH_X)
173			x = chdata & MAX_12BIT;
174		else if (ch == CH_Y)
175			y = chdata & MAX_12BIT;
176		else
177			dev_warn(dev, "unknown channel %d [0x%04x]\n", ch,
178				 chdata);
179	}
180
181	touchscreen_report_pos(ts->input, &ts->props, x, y, false);
182	input_report_key(ts->input, BTN_TOUCH, 1);
183	input_sync(ts->input);
184	dev_dbg(dev, "point(%4d,%4d)\n", x, y);
185
186	mod_timer(&ts->timer, jiffies + SX8650_PENIRQ_TIMEOUT);
187	spin_unlock_irqrestore(&ts->lock, flags);
188
189	return IRQ_HANDLED;
190}
191
192static irqreturn_t sx8654_irq(int irq, void *handle)
193{
194	struct sx8654 *sx8654 = handle;
195	int irqsrc;
196	u8 data[4];
197	unsigned int x, y;
198	int retval;
199
200	irqsrc = i2c_smbus_read_byte_data(sx8654->client,
201					  CMD_READ_REGISTER | I2C_REG_IRQSRC);
202	dev_dbg(&sx8654->client->dev, "irqsrc = 0x%x", irqsrc);
203
204	if (irqsrc < 0)
205		goto out;
206
207	if (irqsrc & IRQ_PENRELEASE) {
208		dev_dbg(&sx8654->client->dev, "pen release interrupt");
209
210		input_report_key(sx8654->input, BTN_TOUCH, 0);
211		input_sync(sx8654->input);
212	}
213
214	if (irqsrc & IRQ_PENTOUCH_TOUCHCONVDONE) {
215		dev_dbg(&sx8654->client->dev, "pen touch interrupt");
216
217		retval = i2c_master_recv(sx8654->client, data, sizeof(data));
218		if (retval != sizeof(data))
219			goto out;
220
221		/* invalid data */
222		if (unlikely(data[0] & 0x80 || data[2] & 0x80))
223			goto out;
224
225		x = ((data[0] & 0xf) << 8) | (data[1]);
226		y = ((data[2] & 0xf) << 8) | (data[3]);
227
228		touchscreen_report_pos(sx8654->input, &sx8654->props, x, y,
229				       false);
230		input_report_key(sx8654->input, BTN_TOUCH, 1);
231		input_sync(sx8654->input);
232
233		dev_dbg(&sx8654->client->dev, "point(%4d,%4d)\n", x, y);
234	}
235
236out:
237	return IRQ_HANDLED;
238}
239
240static int sx8654_reset(struct sx8654 *ts)
241{
242	int err;
243
244	if (ts->gpio_reset) {
245		gpiod_set_value_cansleep(ts->gpio_reset, 1);
246		udelay(2); /* Tpulse > 1��s */
247		gpiod_set_value_cansleep(ts->gpio_reset, 0);
248	} else {
249		dev_dbg(&ts->client->dev, "NRST unavailable, try softreset\n");
250		err = i2c_smbus_write_byte_data(ts->client, I2C_REG_SOFTRESET,
251						SOFTRESET_VALUE);
252		if (err)
253			return err;
254	}
255
256	return 0;
257}
258
259static int sx8654_open(struct input_dev *dev)
260{
261	struct sx8654 *sx8654 = input_get_drvdata(dev);
262	struct i2c_client *client = sx8654->client;
263	int error;
264
265	/* enable pen trigger mode */
266	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0,
267					  RATE_5000CPS | POWDLY_1_1MS);
268	if (error) {
269		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
270		return error;
271	}
272
273	error = i2c_smbus_write_byte(client, CMD_PENTRG);
274	if (error) {
275		dev_err(&client->dev, "writing command CMD_PENTRG failed");
276		return error;
277	}
278
279	enable_irq(client->irq);
280
281	return 0;
282}
283
284static void sx8654_close(struct input_dev *dev)
285{
286	struct sx8654 *sx8654 = input_get_drvdata(dev);
287	struct i2c_client *client = sx8654->client;
288	int error;
289
290	disable_irq(client->irq);
291
292	if (!sx8654->data->has_irq_penrelease)
293		del_timer_sync(&sx8654->timer);
294
295	/* enable manual mode mode */
296	error = i2c_smbus_write_byte(client, sx8654->data->cmd_manual);
297	if (error) {
298		dev_err(&client->dev, "writing command CMD_MANUAL failed");
299		return;
300	}
301
302	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, RATE_MANUAL);
303	if (error) {
304		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
305		return;
306	}
307}
308
309static int sx8654_probe(struct i2c_client *client)
310{
311	const struct i2c_device_id *id = i2c_client_get_device_id(client);
312	struct sx8654 *sx8654;
313	struct input_dev *input;
314	int error;
315
316	if (!i2c_check_functionality(client->adapter,
317				     I2C_FUNC_SMBUS_READ_WORD_DATA))
318		return -ENXIO;
319
320	sx8654 = devm_kzalloc(&client->dev, sizeof(*sx8654), GFP_KERNEL);
321	if (!sx8654)
322		return -ENOMEM;
323
324	sx8654->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
325						     GPIOD_OUT_HIGH);
326	if (IS_ERR(sx8654->gpio_reset))
327		return dev_err_probe(&client->dev, PTR_ERR(sx8654->gpio_reset),
328				     "unable to get reset-gpio\n");
329	dev_dbg(&client->dev, "got GPIO reset pin\n");
330
331	sx8654->data = device_get_match_data(&client->dev);
332	if (!sx8654->data)
333		sx8654->data = (const struct sx865x_data *)id->driver_data;
334	if (!sx8654->data) {
335		dev_err(&client->dev, "invalid or missing device data\n");
336		return -EINVAL;
337	}
338
339	if (!sx8654->data->has_irq_penrelease) {
340		dev_dbg(&client->dev, "use timer for penrelease\n");
341		timer_setup(&sx8654->timer, sx865x_penrelease_timer_handler, 0);
342		spin_lock_init(&sx8654->lock);
343	}
344
345	input = devm_input_allocate_device(&client->dev);
346	if (!input)
347		return -ENOMEM;
348
349	input->name = "SX8654 I2C Touchscreen";
350	input->id.bustype = BUS_I2C;
351	input->dev.parent = &client->dev;
352	input->open = sx8654_open;
353	input->close = sx8654_close;
354
355	__set_bit(INPUT_PROP_DIRECT, input->propbit);
356	input_set_capability(input, EV_KEY, BTN_TOUCH);
357	input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
358	input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
359
360	touchscreen_parse_properties(input, false, &sx8654->props);
361
362	sx8654->client = client;
363	sx8654->input = input;
364
365	input_set_drvdata(sx8654->input, sx8654);
366
367	error = sx8654_reset(sx8654);
368	if (error) {
369		dev_err(&client->dev, "reset failed");
370		return error;
371	}
372
373	error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
374					  sx8654->data->chan_mask);
375	if (error) {
376		dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
377		return error;
378	}
379
380	if (sx8654->data->has_reg_irqmask) {
381		error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
382						  IRQ_PENTOUCH_TOUCHCONVDONE |
383							IRQ_PENRELEASE);
384		if (error) {
385			dev_err(&client->dev, "writing I2C_REG_IRQMASK failed");
386			return error;
387		}
388	}
389
390	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
391					  CONDIRQ | RPDNT_100K | FILT_7SA);
392	if (error) {
393		dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
394		return error;
395	}
396
397	error = devm_request_threaded_irq(&client->dev, client->irq,
398					  NULL, sx8654->data->irqh,
399					  IRQF_ONESHOT,
400					  client->name, sx8654);
401	if (error) {
402		dev_err(&client->dev,
403			"Failed to enable IRQ %d, error: %d\n",
404			client->irq, error);
405		return error;
406	}
407
408	/* Disable the IRQ, we'll enable it in sx8654_open() */
409	disable_irq(client->irq);
410
411	error = input_register_device(sx8654->input);
412	if (error)
413		return error;
414
415	return 0;
416}
417
418static const struct sx865x_data sx8650_data = {
419	.cmd_manual		= 0xb0,
420	.has_irq_penrelease	= false,
421	.has_reg_irqmask	= false,
422	.chan_mask		= (CONV_X | CONV_Y),
423	.irqh			= sx8650_irq,
424};
425
426static const struct sx865x_data sx8654_data = {
427	.cmd_manual		= 0xc0,
428	.has_irq_penrelease	= true,
429	.has_reg_irqmask	= true,
430	.chan_mask		= (CONV_X | CONV_Y),
431	.irqh			= sx8654_irq,
432};
433
434#ifdef CONFIG_OF
435static const struct of_device_id sx8654_of_match[] = {
436	{
437		.compatible = "semtech,sx8650",
438		.data = &sx8650_data,
439	}, {
440		.compatible = "semtech,sx8654",
441		.data = &sx8654_data,
442	}, {
443		.compatible = "semtech,sx8655",
444		.data = &sx8654_data,
445	}, {
446		.compatible = "semtech,sx8656",
447		.data = &sx8654_data,
448	},
449	{ }
450};
451MODULE_DEVICE_TABLE(of, sx8654_of_match);
452#endif
453
454static const struct i2c_device_id sx8654_id_table[] = {
455	{ .name = "semtech_sx8650", .driver_data = (long)&sx8650_data },
456	{ .name = "semtech_sx8654", .driver_data = (long)&sx8654_data },
457	{ .name = "semtech_sx8655", .driver_data = (long)&sx8654_data },
458	{ .name = "semtech_sx8656", .driver_data = (long)&sx8654_data },
459	{ }
460};
461MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
462
463static struct i2c_driver sx8654_driver = {
464	.driver = {
465		.name = "sx8654",
466		.of_match_table = of_match_ptr(sx8654_of_match),
467	},
468	.id_table = sx8654_id_table,
469	.probe = sx8654_probe,
470};
471module_i2c_driver(sx8654_driver);
472
473MODULE_AUTHOR("S��bastien Szymanski <sebastien.szymanski@armadeus.com>");
474MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
475MODULE_LICENSE("GPL");
476