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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 * Sébastien 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 > 1µs */
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 error = PTR_ERR(sx8654->gpio_reset);
328 if (error != -EPROBE_DEFER)
329 dev_err(&client->dev, "unable to get reset-gpio: %d\n",
330 error);
331 return error;
332 }
333 dev_dbg(&client->dev, "got GPIO reset pin\n");
334
335 sx8654->data = device_get_match_data(&client->dev);
336 if (!sx8654->data)
337 sx8654->data = (const struct sx865x_data *)id->driver_data;
338 if (!sx8654->data) {
339 dev_err(&client->dev, "invalid or missing device data\n");
340 return -EINVAL;
341 }
342
343 if (!sx8654->data->has_irq_penrelease) {
344 dev_dbg(&client->dev, "use timer for penrelease\n");
345 timer_setup(&sx8654->timer, sx865x_penrelease_timer_handler, 0);
346 spin_lock_init(&sx8654->lock);
347 }
348
349 input = devm_input_allocate_device(&client->dev);
350 if (!input)
351 return -ENOMEM;
352
353 input->name = "SX8654 I2C Touchscreen";
354 input->id.bustype = BUS_I2C;
355 input->dev.parent = &client->dev;
356 input->open = sx8654_open;
357 input->close = sx8654_close;
358
359 __set_bit(INPUT_PROP_DIRECT, input->propbit);
360 input_set_capability(input, EV_KEY, BTN_TOUCH);
361 input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
362 input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
363
364 touchscreen_parse_properties(input, false, &sx8654->props);
365
366 sx8654->client = client;
367 sx8654->input = input;
368
369 input_set_drvdata(sx8654->input, sx8654);
370
371 error = sx8654_reset(sx8654);
372 if (error) {
373 dev_err(&client->dev, "reset failed");
374 return error;
375 }
376
377 error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
378 sx8654->data->chan_mask);
379 if (error) {
380 dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
381 return error;
382 }
383
384 if (sx8654->data->has_reg_irqmask) {
385 error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
386 IRQ_PENTOUCH_TOUCHCONVDONE |
387 IRQ_PENRELEASE);
388 if (error) {
389 dev_err(&client->dev, "writing I2C_REG_IRQMASK failed");
390 return error;
391 }
392 }
393
394 error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
395 CONDIRQ | RPDNT_100K | FILT_7SA);
396 if (error) {
397 dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
398 return error;
399 }
400
401 error = devm_request_threaded_irq(&client->dev, client->irq,
402 NULL, sx8654->data->irqh,
403 IRQF_ONESHOT,
404 client->name, sx8654);
405 if (error) {
406 dev_err(&client->dev,
407 "Failed to enable IRQ %d, error: %d\n",
408 client->irq, error);
409 return error;
410 }
411
412 /* Disable the IRQ, we'll enable it in sx8654_open() */
413 disable_irq(client->irq);
414
415 error = input_register_device(sx8654->input);
416 if (error)
417 return error;
418
419 return 0;
420}
421
422static const struct sx865x_data sx8650_data = {
423 .cmd_manual = 0xb0,
424 .has_irq_penrelease = false,
425 .has_reg_irqmask = false,
426 .chan_mask = (CONV_X | CONV_Y),
427 .irqh = sx8650_irq,
428};
429
430static const struct sx865x_data sx8654_data = {
431 .cmd_manual = 0xc0,
432 .has_irq_penrelease = true,
433 .has_reg_irqmask = true,
434 .chan_mask = (CONV_X | CONV_Y),
435 .irqh = sx8654_irq,
436};
437
438#ifdef CONFIG_OF
439static const struct of_device_id sx8654_of_match[] = {
440 {
441 .compatible = "semtech,sx8650",
442 .data = &sx8650_data,
443 }, {
444 .compatible = "semtech,sx8654",
445 .data = &sx8654_data,
446 }, {
447 .compatible = "semtech,sx8655",
448 .data = &sx8654_data,
449 }, {
450 .compatible = "semtech,sx8656",
451 .data = &sx8654_data,
452 },
453 { }
454};
455MODULE_DEVICE_TABLE(of, sx8654_of_match);
456#endif
457
458static const struct i2c_device_id sx8654_id_table[] = {
459 { .name = "semtech_sx8650", .driver_data = (long)&sx8650_data },
460 { .name = "semtech_sx8654", .driver_data = (long)&sx8654_data },
461 { .name = "semtech_sx8655", .driver_data = (long)&sx8654_data },
462 { .name = "semtech_sx8656", .driver_data = (long)&sx8654_data },
463 { }
464};
465MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
466
467static struct i2c_driver sx8654_driver = {
468 .driver = {
469 .name = "sx8654",
470 .of_match_table = of_match_ptr(sx8654_of_match),
471 },
472 .id_table = sx8654_id_table,
473 .probe_new = sx8654_probe,
474};
475module_i2c_driver(sx8654_driver);
476
477MODULE_AUTHOR("Sébastien Szymanski <sebastien.szymanski@armadeus.com>");
478MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
479MODULE_LICENSE("GPL");