1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/crc-ccitt.h>
3 #include <linux/delay.h>
4 #include <linux/gpio/consumer.h>
5 #include <linux/i2c.h>
6 #include <linux/ihex.h>
7 #include <linux/input.h>
8 #include <linux/input/mt.h>
9 #include <linux/input/touchscreen.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
12 #include <linux/of_device.h>
13 #include <linux/sizes.h>
14 #include <linux/slab.h>
15 #include <asm/unaligned.h>
16 
17 #define ILI2XXX_POLL_PERIOD	15
18 
19 #define ILI210X_DATA_SIZE	64
20 #define ILI211X_DATA_SIZE	43
21 #define ILI251X_DATA_SIZE1	31
22 #define ILI251X_DATA_SIZE2	20
23 
24 /* Touchscreen commands */
25 #define REG_TOUCHDATA		0x10
26 #define REG_PANEL_INFO		0x20
27 #define REG_FIRMWARE_VERSION	0x40
28 #define REG_PROTOCOL_VERSION	0x42
29 #define REG_KERNEL_VERSION	0x61
30 #define REG_IC_BUSY		0x80
31 #define REG_IC_BUSY_NOT_BUSY	0x50
32 #define REG_GET_MODE		0xc0
33 #define REG_GET_MODE_AP		0x5a
34 #define REG_GET_MODE_BL		0x55
35 #define REG_SET_MODE_AP		0xc1
36 #define REG_SET_MODE_BL		0xc2
37 #define REG_WRITE_DATA		0xc3
38 #define REG_WRITE_ENABLE	0xc4
39 #define REG_READ_DATA_CRC	0xc7
40 #define REG_CALIBRATE		0xcc
41 
42 #define ILI251X_FW_FILENAME	"ilitek/ili251x.bin"
43 
44 struct ili2xxx_chip {
45 	int (*read_reg)(struct i2c_client *client, u8 reg,
46 			void *buf, size_t len);
47 	int (*get_touch_data)(struct i2c_client *client, u8 *data);
48 	bool (*parse_touch_data)(const u8 *data, unsigned int finger,
49 				 unsigned int *x, unsigned int *y,
50 				 unsigned int *z);
51 	bool (*continue_polling)(const u8 *data, bool touch);
52 	unsigned int max_touches;
53 	unsigned int resolution;
54 	bool has_calibrate_reg;
55 	bool has_firmware_proto;
56 	bool has_pressure_reg;
57 };
58 
59 struct ili210x {
60 	struct i2c_client *client;
61 	struct input_dev *input;
62 	struct gpio_desc *reset_gpio;
63 	struct touchscreen_properties prop;
64 	const struct ili2xxx_chip *chip;
65 	u8 version_firmware[8];
66 	u8 version_kernel[5];
67 	u8 version_proto[2];
68 	u8 ic_mode[2];
69 	bool stop;
70 };
71 
72 static int ili210x_read_reg(struct i2c_client *client,
73 			    u8 reg, void *buf, size_t len)
74 {
75 	struct i2c_msg msg[] = {
76 		{
77 			.addr	= client->addr,
78 			.flags	= 0,
79 			.len	= 1,
80 			.buf	= &reg,
81 		},
82 		{
83 			.addr	= client->addr,
84 			.flags	= I2C_M_RD,
85 			.len	= len,
86 			.buf	= buf,
87 		}
88 	};
89 	int error, ret;
90 
91 	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
92 	if (ret != ARRAY_SIZE(msg)) {
93 		error = ret < 0 ? ret : -EIO;
94 		dev_err(&client->dev, "%s failed: %d\n", __func__, error);
95 		return error;
96 	}
97 
98 	return 0;
99 }
100 
101 static int ili210x_read_touch_data(struct i2c_client *client, u8 *data)
102 {
103 	return ili210x_read_reg(client, REG_TOUCHDATA,
104 				data, ILI210X_DATA_SIZE);
105 }
106 
107 static bool ili210x_touchdata_to_coords(const u8 *touchdata,
108 					unsigned int finger,
109 					unsigned int *x, unsigned int *y,
110 					unsigned int *z)
111 {
112 	if (!(touchdata[0] & BIT(finger)))
113 		return false;
114 
115 	*x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
116 	*y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
117 
118 	return true;
119 }
120 
121 static bool ili210x_check_continue_polling(const u8 *data, bool touch)
122 {
123 	return data[0] & 0xf3;
124 }
125 
126 static const struct ili2xxx_chip ili210x_chip = {
127 	.read_reg		= ili210x_read_reg,
128 	.get_touch_data		= ili210x_read_touch_data,
129 	.parse_touch_data	= ili210x_touchdata_to_coords,
130 	.continue_polling	= ili210x_check_continue_polling,
131 	.max_touches		= 2,
132 	.has_calibrate_reg	= true,
133 };
134 
135 static int ili211x_read_touch_data(struct i2c_client *client, u8 *data)
136 {
137 	s16 sum = 0;
138 	int error;
139 	int ret;
140 	int i;
141 
142 	ret = i2c_master_recv(client, data, ILI211X_DATA_SIZE);
143 	if (ret != ILI211X_DATA_SIZE) {
144 		error = ret < 0 ? ret : -EIO;
145 		dev_err(&client->dev, "%s failed: %d\n", __func__, error);
146 		return error;
147 	}
148 
149 	/* This chip uses custom checksum at the end of data */
150 	for (i = 0; i < ILI211X_DATA_SIZE - 1; i++)
151 		sum = (sum + data[i]) & 0xff;
152 
153 	if ((-sum & 0xff) != data[ILI211X_DATA_SIZE - 1]) {
154 		dev_err(&client->dev,
155 			"CRC error (crc=0x%02x expected=0x%02x)\n",
156 			sum, data[ILI211X_DATA_SIZE - 1]);
157 		return -EIO;
158 	}
159 
160 	return 0;
161 }
162 
163 static bool ili211x_touchdata_to_coords(const u8 *touchdata,
164 					unsigned int finger,
165 					unsigned int *x, unsigned int *y,
166 					unsigned int *z)
167 {
168 	u32 data;
169 
170 	data = get_unaligned_be32(touchdata + 1 + (finger * 4) + 0);
171 	if (data == 0xffffffff)	/* Finger up */
172 		return false;
173 
174 	*x = ((touchdata[1 + (finger * 4) + 0] & 0xf0) << 4) |
175 	     touchdata[1 + (finger * 4) + 1];
176 	*y = ((touchdata[1 + (finger * 4) + 0] & 0x0f) << 8) |
177 	     touchdata[1 + (finger * 4) + 2];
178 
179 	return true;
180 }
181 
182 static bool ili211x_decline_polling(const u8 *data, bool touch)
183 {
184 	return false;
185 }
186 
187 static const struct ili2xxx_chip ili211x_chip = {
188 	.read_reg		= ili210x_read_reg,
189 	.get_touch_data		= ili211x_read_touch_data,
190 	.parse_touch_data	= ili211x_touchdata_to_coords,
191 	.continue_polling	= ili211x_decline_polling,
192 	.max_touches		= 10,
193 	.resolution		= 2048,
194 };
195 
196 static bool ili212x_touchdata_to_coords(const u8 *touchdata,
197 					unsigned int finger,
198 					unsigned int *x, unsigned int *y,
199 					unsigned int *z)
200 {
201 	u16 val;
202 
203 	val = get_unaligned_be16(touchdata + 3 + (finger * 5) + 0);
204 	if (!(val & BIT(15)))	/* Touch indication */
205 		return false;
206 
207 	*x = val & 0x3fff;
208 	*y = get_unaligned_be16(touchdata + 3 + (finger * 5) + 2);
209 
210 	return true;
211 }
212 
213 static bool ili212x_check_continue_polling(const u8 *data, bool touch)
214 {
215 	return touch;
216 }
217 
218 static const struct ili2xxx_chip ili212x_chip = {
219 	.read_reg		= ili210x_read_reg,
220 	.get_touch_data		= ili210x_read_touch_data,
221 	.parse_touch_data	= ili212x_touchdata_to_coords,
222 	.continue_polling	= ili212x_check_continue_polling,
223 	.max_touches		= 10,
224 	.has_calibrate_reg	= true,
225 };
226 
227 static int ili251x_read_reg_common(struct i2c_client *client,
228 				   u8 reg, void *buf, size_t len,
229 				   unsigned int delay)
230 {
231 	int error;
232 	int ret;
233 
234 	ret = i2c_master_send(client, &reg, 1);
235 	if (ret == 1) {
236 		if (delay)
237 			usleep_range(delay, delay + 500);
238 
239 		ret = i2c_master_recv(client, buf, len);
240 		if (ret == len)
241 			return 0;
242 	}
243 
244 	error = ret < 0 ? ret : -EIO;
245 	dev_err(&client->dev, "%s failed: %d\n", __func__, error);
246 	return ret;
247 }
248 
249 static int ili251x_read_reg(struct i2c_client *client,
250 			    u8 reg, void *buf, size_t len)
251 {
252 	return ili251x_read_reg_common(client, reg, buf, len, 5000);
253 }
254 
255 static int ili251x_read_touch_data(struct i2c_client *client, u8 *data)
256 {
257 	int error;
258 
259 	error = ili251x_read_reg_common(client, REG_TOUCHDATA,
260 					data, ILI251X_DATA_SIZE1, 0);
261 	if (!error && data[0] == 2) {
262 		error = i2c_master_recv(client, data + ILI251X_DATA_SIZE1,
263 					ILI251X_DATA_SIZE2);
264 		if (error >= 0 && error != ILI251X_DATA_SIZE2)
265 			error = -EIO;
266 	}
267 
268 	return error;
269 }
270 
271 static bool ili251x_touchdata_to_coords(const u8 *touchdata,
272 					unsigned int finger,
273 					unsigned int *x, unsigned int *y,
274 					unsigned int *z)
275 {
276 	u16 val;
277 
278 	val = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
279 	if (!(val & BIT(15)))	/* Touch indication */
280 		return false;
281 
282 	*x = val & 0x3fff;
283 	*y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
284 	*z = touchdata[1 + (finger * 5) + 4];
285 
286 	return true;
287 }
288 
289 static bool ili251x_check_continue_polling(const u8 *data, bool touch)
290 {
291 	return touch;
292 }
293 
294 static const struct ili2xxx_chip ili251x_chip = {
295 	.read_reg		= ili251x_read_reg,
296 	.get_touch_data		= ili251x_read_touch_data,
297 	.parse_touch_data	= ili251x_touchdata_to_coords,
298 	.continue_polling	= ili251x_check_continue_polling,
299 	.max_touches		= 10,
300 	.has_calibrate_reg	= true,
301 	.has_firmware_proto	= true,
302 	.has_pressure_reg	= true,
303 };
304 
305 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
306 {
307 	struct input_dev *input = priv->input;
308 	int i;
309 	bool contact = false, touch;
310 	unsigned int x = 0, y = 0, z = 0;
311 
312 	for (i = 0; i < priv->chip->max_touches; i++) {
313 		touch = priv->chip->parse_touch_data(touchdata, i, &x, &y, &z);
314 
315 		input_mt_slot(input, i);
316 		if (input_mt_report_slot_state(input, MT_TOOL_FINGER, touch)) {
317 			touchscreen_report_pos(input, &priv->prop, x, y, true);
318 			if (priv->chip->has_pressure_reg)
319 				input_report_abs(input, ABS_MT_PRESSURE, z);
320 			contact = true;
321 		}
322 	}
323 
324 	input_mt_report_pointer_emulation(input, false);
325 	input_sync(input);
326 
327 	return contact;
328 }
329 
330 static irqreturn_t ili210x_irq(int irq, void *irq_data)
331 {
332 	struct ili210x *priv = irq_data;
333 	struct i2c_client *client = priv->client;
334 	const struct ili2xxx_chip *chip = priv->chip;
335 	u8 touchdata[ILI210X_DATA_SIZE] = { 0 };
336 	bool keep_polling;
337 	ktime_t time_next;
338 	s64 time_delta;
339 	bool touch;
340 	int error;
341 
342 	do {
343 		time_next = ktime_add_ms(ktime_get(), ILI2XXX_POLL_PERIOD);
344 		error = chip->get_touch_data(client, touchdata);
345 		if (error) {
346 			dev_err(&client->dev,
347 				"Unable to get touch data: %d\n", error);
348 			break;
349 		}
350 
351 		touch = ili210x_report_events(priv, touchdata);
352 		keep_polling = chip->continue_polling(touchdata, touch);
353 		if (keep_polling) {
354 			time_delta = ktime_us_delta(time_next, ktime_get());
355 			if (time_delta > 0)
356 				usleep_range(time_delta, time_delta + 1000);
357 		}
358 	} while (!priv->stop && keep_polling);
359 
360 	return IRQ_HANDLED;
361 }
362 
363 static int ili251x_firmware_update_resolution(struct device *dev)
364 {
365 	struct i2c_client *client = to_i2c_client(dev);
366 	struct ili210x *priv = i2c_get_clientdata(client);
367 	u16 resx, resy;
368 	u8 rs[10];
369 	int error;
370 
371 	/* The firmware update blob might have changed the resolution. */
372 	error = priv->chip->read_reg(client, REG_PANEL_INFO, &rs, sizeof(rs));
373 	if (error)
374 		return error;
375 
376 	resx = le16_to_cpup((__le16 *)rs);
377 	resy = le16_to_cpup((__le16 *)(rs + 2));
378 
379 	/* The value reported by the firmware is invalid. */
380 	if (!resx || resx == 0xffff || !resy || resy == 0xffff)
381 		return -EINVAL;
382 
383 	input_abs_set_max(priv->input, ABS_X, resx - 1);
384 	input_abs_set_max(priv->input, ABS_Y, resy - 1);
385 	input_abs_set_max(priv->input, ABS_MT_POSITION_X, resx - 1);
386 	input_abs_set_max(priv->input, ABS_MT_POSITION_Y, resy - 1);
387 
388 	return 0;
389 }
390 
391 static ssize_t ili251x_firmware_update_firmware_version(struct device *dev)
392 {
393 	struct i2c_client *client = to_i2c_client(dev);
394 	struct ili210x *priv = i2c_get_clientdata(client);
395 	int error;
396 	u8 fw[8];
397 
398 	/* Get firmware version */
399 	error = priv->chip->read_reg(client, REG_FIRMWARE_VERSION,
400 				     &fw, sizeof(fw));
401 	if (!error)
402 		memcpy(priv->version_firmware, fw, sizeof(fw));
403 
404 	return error;
405 }
406 
407 static ssize_t ili251x_firmware_update_kernel_version(struct device *dev)
408 {
409 	struct i2c_client *client = to_i2c_client(dev);
410 	struct ili210x *priv = i2c_get_clientdata(client);
411 	int error;
412 	u8 kv[5];
413 
414 	/* Get kernel version */
415 	error = priv->chip->read_reg(client, REG_KERNEL_VERSION,
416 				     &kv, sizeof(kv));
417 	if (!error)
418 		memcpy(priv->version_kernel, kv, sizeof(kv));
419 
420 	return error;
421 }
422 
423 static ssize_t ili251x_firmware_update_protocol_version(struct device *dev)
424 {
425 	struct i2c_client *client = to_i2c_client(dev);
426 	struct ili210x *priv = i2c_get_clientdata(client);
427 	int error;
428 	u8 pv[2];
429 
430 	/* Get protocol version */
431 	error = priv->chip->read_reg(client, REG_PROTOCOL_VERSION,
432 				     &pv, sizeof(pv));
433 	if (!error)
434 		memcpy(priv->version_proto, pv, sizeof(pv));
435 
436 	return error;
437 }
438 
439 static ssize_t ili251x_firmware_update_ic_mode(struct device *dev)
440 {
441 	struct i2c_client *client = to_i2c_client(dev);
442 	struct ili210x *priv = i2c_get_clientdata(client);
443 	int error;
444 	u8 md[2];
445 
446 	/* Get chip boot mode */
447 	error = priv->chip->read_reg(client, REG_GET_MODE, &md, sizeof(md));
448 	if (!error)
449 		memcpy(priv->ic_mode, md, sizeof(md));
450 
451 	return error;
452 }
453 
454 static int ili251x_firmware_update_cached_state(struct device *dev)
455 {
456 	struct i2c_client *client = to_i2c_client(dev);
457 	struct ili210x *priv = i2c_get_clientdata(client);
458 	int error;
459 
460 	if (!priv->chip->has_firmware_proto)
461 		return 0;
462 
463 	/* Wait for firmware to boot and stabilize itself. */
464 	msleep(200);
465 
466 	/* Firmware does report valid information. */
467 	error = ili251x_firmware_update_resolution(dev);
468 	if (error)
469 		return error;
470 
471 	error = ili251x_firmware_update_firmware_version(dev);
472 	if (error)
473 		return error;
474 
475 	error = ili251x_firmware_update_kernel_version(dev);
476 	if (error)
477 		return error;
478 
479 	error = ili251x_firmware_update_protocol_version(dev);
480 	if (error)
481 		return error;
482 
483 	error = ili251x_firmware_update_ic_mode(dev);
484 	if (error)
485 		return error;
486 
487 	return 0;
488 }
489 
490 static ssize_t ili251x_firmware_version_show(struct device *dev,
491 					     struct device_attribute *attr,
492 					     char *buf)
493 {
494 	struct i2c_client *client = to_i2c_client(dev);
495 	struct ili210x *priv = i2c_get_clientdata(client);
496 	u8 *fw = priv->version_firmware;
497 
498 	return sysfs_emit(buf, "%02x%02x.%02x%02x.%02x%02x.%02x%02x\n",
499 			  fw[0], fw[1], fw[2], fw[3],
500 			  fw[4], fw[5], fw[6], fw[7]);
501 }
502 static DEVICE_ATTR(firmware_version, 0444, ili251x_firmware_version_show, NULL);
503 
504 static ssize_t ili251x_kernel_version_show(struct device *dev,
505 					   struct device_attribute *attr,
506 					   char *buf)
507 {
508 	struct i2c_client *client = to_i2c_client(dev);
509 	struct ili210x *priv = i2c_get_clientdata(client);
510 	u8 *kv = priv->version_kernel;
511 
512 	return sysfs_emit(buf, "%02x.%02x.%02x.%02x.%02x\n",
513 			  kv[0], kv[1], kv[2], kv[3], kv[4]);
514 }
515 static DEVICE_ATTR(kernel_version, 0444, ili251x_kernel_version_show, NULL);
516 
517 static ssize_t ili251x_protocol_version_show(struct device *dev,
518 					     struct device_attribute *attr,
519 					     char *buf)
520 {
521 	struct i2c_client *client = to_i2c_client(dev);
522 	struct ili210x *priv = i2c_get_clientdata(client);
523 	u8 *pv = priv->version_proto;
524 
525 	return sysfs_emit(buf, "%02x.%02x\n", pv[0], pv[1]);
526 }
527 static DEVICE_ATTR(protocol_version, 0444, ili251x_protocol_version_show, NULL);
528 
529 static ssize_t ili251x_mode_show(struct device *dev,
530 				 struct device_attribute *attr, char *buf)
531 {
532 	struct i2c_client *client = to_i2c_client(dev);
533 	struct ili210x *priv = i2c_get_clientdata(client);
534 	u8 *md = priv->ic_mode;
535 	char *mode = "AP";
536 
537 	if (md[0] == REG_GET_MODE_AP)		/* Application Mode */
538 		mode = "AP";
539 	else if (md[0] == REG_GET_MODE_BL)	/* BootLoader Mode */
540 		mode = "BL";
541 	else					/* Unknown Mode */
542 		mode = "??";
543 
544 	return sysfs_emit(buf, "%02x.%02x:%s\n", md[0], md[1], mode);
545 }
546 static DEVICE_ATTR(mode, 0444, ili251x_mode_show, NULL);
547 
548 static ssize_t ili210x_calibrate(struct device *dev,
549 				 struct device_attribute *attr,
550 				 const char *buf, size_t count)
551 {
552 	struct i2c_client *client = to_i2c_client(dev);
553 	struct ili210x *priv = i2c_get_clientdata(client);
554 	unsigned long calibrate;
555 	int rc;
556 	u8 cmd = REG_CALIBRATE;
557 
558 	if (kstrtoul(buf, 10, &calibrate))
559 		return -EINVAL;
560 
561 	if (calibrate > 1)
562 		return -EINVAL;
563 
564 	if (calibrate) {
565 		rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
566 		if (rc != sizeof(cmd))
567 			return -EIO;
568 	}
569 
570 	return count;
571 }
572 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
573 
574 static int ili251x_firmware_to_buffer(const struct firmware *fw,
575 				      u8 **buf, u16 *ac_end, u16 *df_end)
576 {
577 	const struct ihex_binrec *rec;
578 	u32 fw_addr, fw_last_addr = 0;
579 	u16 fw_len;
580 	u8 *fw_buf;
581 	int error;
582 
583 	/*
584 	 * The firmware ihex blob can never be bigger than 64 kiB, so make this
585 	 * simple -- allocate a 64 kiB buffer, iterate over the ihex blob records
586 	 * once, copy them all into this buffer at the right locations, and then
587 	 * do all operations on this linear buffer.
588 	 */
589 	fw_buf = kzalloc(SZ_64K, GFP_KERNEL);
590 	if (!fw_buf)
591 		return -ENOMEM;
592 
593 	rec = (const struct ihex_binrec *)fw->data;
594 	while (rec) {
595 		fw_addr = be32_to_cpu(rec->addr);
596 		fw_len = be16_to_cpu(rec->len);
597 
598 		/* The last 32 Byte firmware block can be 0xffe0 */
599 		if (fw_addr + fw_len > SZ_64K || fw_addr > SZ_64K - 32) {
600 			error = -EFBIG;
601 			goto err_big;
602 		}
603 
604 		/* Find the last address before DF start address, that is AC end */
605 		if (fw_addr == 0xf000)
606 			*ac_end = fw_last_addr;
607 		fw_last_addr = fw_addr + fw_len;
608 
609 		memcpy(fw_buf + fw_addr, rec->data, fw_len);
610 		rec = ihex_next_binrec(rec);
611 	}
612 
613 	/* DF end address is the last address in the firmware blob */
614 	*df_end = fw_addr + fw_len;
615 	*buf = fw_buf;
616 	return 0;
617 
618 err_big:
619 	kfree(fw_buf);
620 	return error;
621 }
622 
623 /* Switch mode between Application and BootLoader */
624 static int ili251x_switch_ic_mode(struct i2c_client *client, u8 cmd_mode)
625 {
626 	struct ili210x *priv = i2c_get_clientdata(client);
627 	u8 cmd_wren[3] = { REG_WRITE_ENABLE, 0x5a, 0xa5 };
628 	u8 md[2];
629 	int error;
630 
631 	error = priv->chip->read_reg(client, REG_GET_MODE, md, sizeof(md));
632 	if (error)
633 		return error;
634 	/* Mode already set */
635 	if ((cmd_mode == REG_SET_MODE_AP && md[0] == REG_GET_MODE_AP) ||
636 	    (cmd_mode == REG_SET_MODE_BL && md[0] == REG_GET_MODE_BL))
637 		return 0;
638 
639 	/* Unlock writes */
640 	error = i2c_master_send(client, cmd_wren, sizeof(cmd_wren));
641 	if (error != sizeof(cmd_wren))
642 		return -EINVAL;
643 
644 	mdelay(20);
645 
646 	/* Select mode (BootLoader or Application) */
647 	error = i2c_master_send(client, &cmd_mode, 1);
648 	if (error != 1)
649 		return -EINVAL;
650 
651 	mdelay(200);	/* Reboot into bootloader takes a lot of time ... */
652 
653 	/* Read back mode */
654 	error = priv->chip->read_reg(client, REG_GET_MODE, md, sizeof(md));
655 	if (error)
656 		return error;
657 	/* Check if mode is correct now. */
658 	if ((cmd_mode == REG_SET_MODE_AP && md[0] == REG_GET_MODE_AP) ||
659 	    (cmd_mode == REG_SET_MODE_BL && md[0] == REG_GET_MODE_BL))
660 		return 0;
661 
662 	return -EINVAL;
663 }
664 
665 static int ili251x_firmware_busy(struct i2c_client *client)
666 {
667 	struct ili210x *priv = i2c_get_clientdata(client);
668 	int error, i = 0;
669 	u8 data;
670 
671 	do {
672 		/* The read_reg already contains suitable delay */
673 		error = priv->chip->read_reg(client, REG_IC_BUSY, &data, 1);
674 		if (error)
675 			return error;
676 		if (i++ == 100000)
677 			return -ETIMEDOUT;
678 	} while (data != REG_IC_BUSY_NOT_BUSY);
679 
680 	return 0;
681 }
682 
683 static int ili251x_firmware_write_to_ic(struct device *dev, u8 *fwbuf,
684 					u16 start, u16 end, u8 dataflash)
685 {
686 	struct i2c_client *client = to_i2c_client(dev);
687 	struct ili210x *priv = i2c_get_clientdata(client);
688 	u8 cmd_crc = REG_READ_DATA_CRC;
689 	u8 crcrb[4] = { 0 };
690 	u8 fw_data[33];
691 	u16 fw_addr;
692 	int error;
693 
694 	/*
695 	 * The DF (dataflash) needs 2 bytes offset for unknown reasons,
696 	 * the AC (application) has 2 bytes CRC16-CCITT at the end.
697 	 */
698 	u16 crc = crc_ccitt(0, fwbuf + start + (dataflash ? 2 : 0),
699 			    end - start - 2);
700 
701 	/* Unlock write to either AC (application) or DF (dataflash) area */
702 	u8 cmd_wr[10] = {
703 		REG_WRITE_ENABLE, 0x5a, 0xa5, dataflash,
704 		(end >> 16) & 0xff, (end >> 8) & 0xff, end & 0xff,
705 		(crc >> 16) & 0xff, (crc >> 8) & 0xff, crc & 0xff
706 	};
707 
708 	error = i2c_master_send(client, cmd_wr, sizeof(cmd_wr));
709 	if (error != sizeof(cmd_wr))
710 		return -EINVAL;
711 
712 	error = ili251x_firmware_busy(client);
713 	if (error)
714 		return error;
715 
716 	for (fw_addr = start; fw_addr < end; fw_addr += 32) {
717 		fw_data[0] = REG_WRITE_DATA;
718 		memcpy(&(fw_data[1]), fwbuf + fw_addr, 32);
719 		error = i2c_master_send(client, fw_data, 33);
720 		if (error != sizeof(fw_data))
721 			return error;
722 		error = ili251x_firmware_busy(client);
723 		if (error)
724 			return error;
725 	}
726 
727 	error = i2c_master_send(client, &cmd_crc, 1);
728 	if (error != 1)
729 		return -EINVAL;
730 
731 	error = ili251x_firmware_busy(client);
732 	if (error)
733 		return error;
734 
735 	error = priv->chip->read_reg(client, REG_READ_DATA_CRC,
736 				   &crcrb, sizeof(crcrb));
737 	if (error)
738 		return error;
739 
740 	/* Check CRC readback */
741 	if ((crcrb[0] != (crc & 0xff)) || crcrb[1] != ((crc >> 8) & 0xff))
742 		return -EINVAL;
743 
744 	return 0;
745 }
746 
747 static int ili251x_firmware_reset(struct i2c_client *client)
748 {
749 	u8 cmd_reset[2] = { 0xf2, 0x01 };
750 	int error;
751 
752 	error = i2c_master_send(client, cmd_reset, sizeof(cmd_reset));
753 	if (error != sizeof(cmd_reset))
754 		return -EINVAL;
755 
756 	return ili251x_firmware_busy(client);
757 }
758 
759 static void ili210x_hardware_reset(struct gpio_desc *reset_gpio)
760 {
761 	/* Reset the controller */
762 	gpiod_set_value_cansleep(reset_gpio, 1);
763 	usleep_range(12000, 15000);
764 	gpiod_set_value_cansleep(reset_gpio, 0);
765 	msleep(300);
766 }
767 
768 static ssize_t ili210x_firmware_update_store(struct device *dev,
769 					     struct device_attribute *attr,
770 					     const char *buf, size_t count)
771 {
772 	struct i2c_client *client = to_i2c_client(dev);
773 	struct ili210x *priv = i2c_get_clientdata(client);
774 	const char *fwname = ILI251X_FW_FILENAME;
775 	const struct firmware *fw;
776 	u16 ac_end, df_end;
777 	u8 *fwbuf;
778 	int error;
779 	int i;
780 
781 	error = request_ihex_firmware(&fw, fwname, dev);
782 	if (error) {
783 		dev_err(dev, "Failed to request firmware %s, error=%d\n",
784 			fwname, error);
785 		return error;
786 	}
787 
788 	error = ili251x_firmware_to_buffer(fw, &fwbuf, &ac_end, &df_end);
789 	release_firmware(fw);
790 	if (error)
791 		return error;
792 
793 	/*
794 	 * Disable touchscreen IRQ, so that we would not get spurious touch
795 	 * interrupt during firmware update, and so that the IRQ handler won't
796 	 * trigger and interfere with the firmware update. There is no bit in
797 	 * the touch controller to disable the IRQs during update, so we have
798 	 * to do it this way here.
799 	 */
800 	disable_irq(client->irq);
801 
802 	dev_dbg(dev, "Firmware update started, firmware=%s\n", fwname);
803 
804 	ili210x_hardware_reset(priv->reset_gpio);
805 
806 	error = ili251x_firmware_reset(client);
807 	if (error)
808 		goto exit;
809 
810 	/* This may not succeed on first try, so re-try a few times. */
811 	for (i = 0; i < 5; i++) {
812 		error = ili251x_switch_ic_mode(client, REG_SET_MODE_BL);
813 		if (!error)
814 			break;
815 	}
816 
817 	if (error)
818 		goto exit;
819 
820 	dev_dbg(dev, "IC is now in BootLoader mode\n");
821 
822 	msleep(200);	/* The bootloader seems to need some time too. */
823 
824 	error = ili251x_firmware_write_to_ic(dev, fwbuf, 0xf000, df_end, 1);
825 	if (error) {
826 		dev_err(dev, "DF firmware update failed, error=%d\n", error);
827 		goto exit;
828 	}
829 
830 	dev_dbg(dev, "DataFlash firmware written\n");
831 
832 	error = ili251x_firmware_write_to_ic(dev, fwbuf, 0x2000, ac_end, 0);
833 	if (error) {
834 		dev_err(dev, "AC firmware update failed, error=%d\n", error);
835 		goto exit;
836 	}
837 
838 	dev_dbg(dev, "Application firmware written\n");
839 
840 	/* This may not succeed on first try, so re-try a few times. */
841 	for (i = 0; i < 5; i++) {
842 		error = ili251x_switch_ic_mode(client, REG_SET_MODE_AP);
843 		if (!error)
844 			break;
845 	}
846 
847 	if (error)
848 		goto exit;
849 
850 	dev_dbg(dev, "IC is now in Application mode\n");
851 
852 	error = ili251x_firmware_update_cached_state(dev);
853 	if (error)
854 		goto exit;
855 
856 	error = count;
857 
858 exit:
859 	ili210x_hardware_reset(priv->reset_gpio);
860 	dev_dbg(dev, "Firmware update ended, error=%i\n", error);
861 	enable_irq(client->irq);
862 	kfree(fwbuf);
863 	return error;
864 }
865 
866 static DEVICE_ATTR(firmware_update, 0200, NULL, ili210x_firmware_update_store);
867 
868 static struct attribute *ili210x_attributes[] = {
869 	&dev_attr_calibrate.attr,
870 	&dev_attr_firmware_update.attr,
871 	&dev_attr_firmware_version.attr,
872 	&dev_attr_kernel_version.attr,
873 	&dev_attr_protocol_version.attr,
874 	&dev_attr_mode.attr,
875 	NULL,
876 };
877 
878 static umode_t ili210x_attributes_visible(struct kobject *kobj,
879 					  struct attribute *attr, int index)
880 {
881 	struct device *dev = kobj_to_dev(kobj);
882 	struct i2c_client *client = to_i2c_client(dev);
883 	struct ili210x *priv = i2c_get_clientdata(client);
884 
885 	/* Calibrate is present on all ILI2xxx which have calibrate register */
886 	if (attr == &dev_attr_calibrate.attr)
887 		return priv->chip->has_calibrate_reg ? attr->mode : 0;
888 
889 	/* Firmware/Kernel/Protocol/BootMode is implememted only for ILI251x */
890 	if (!priv->chip->has_firmware_proto)
891 		return 0;
892 
893 	return attr->mode;
894 }
895 
896 static const struct attribute_group ili210x_attr_group = {
897 	.attrs = ili210x_attributes,
898 	.is_visible = ili210x_attributes_visible,
899 };
900 
901 static void ili210x_power_down(void *data)
902 {
903 	struct gpio_desc *reset_gpio = data;
904 
905 	gpiod_set_value_cansleep(reset_gpio, 1);
906 }
907 
908 static void ili210x_stop(void *data)
909 {
910 	struct ili210x *priv = data;
911 
912 	/* Tell ISR to quit even if there is a contact. */
913 	priv->stop = true;
914 }
915 
916 static int ili210x_i2c_probe(struct i2c_client *client)
917 {
918 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
919 	struct device *dev = &client->dev;
920 	const struct ili2xxx_chip *chip;
921 	struct ili210x *priv;
922 	struct gpio_desc *reset_gpio;
923 	struct input_dev *input;
924 	int error;
925 	unsigned int max_xy;
926 
927 	dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
928 
929 	chip = device_get_match_data(dev);
930 	if (!chip && id)
931 		chip = (const struct ili2xxx_chip *)id->driver_data;
932 	if (!chip) {
933 		dev_err(&client->dev, "unknown device model\n");
934 		return -ENODEV;
935 	}
936 
937 	if (client->irq <= 0) {
938 		dev_err(dev, "No IRQ!\n");
939 		return -EINVAL;
940 	}
941 
942 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
943 	if (IS_ERR(reset_gpio))
944 		return PTR_ERR(reset_gpio);
945 
946 	if (reset_gpio) {
947 		error = devm_add_action_or_reset(dev, ili210x_power_down,
948 						 reset_gpio);
949 		if (error)
950 			return error;
951 
952 		ili210x_hardware_reset(reset_gpio);
953 	}
954 
955 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
956 	if (!priv)
957 		return -ENOMEM;
958 
959 	input = devm_input_allocate_device(dev);
960 	if (!input)
961 		return -ENOMEM;
962 
963 	priv->client = client;
964 	priv->input = input;
965 	priv->reset_gpio = reset_gpio;
966 	priv->chip = chip;
967 	i2c_set_clientdata(client, priv);
968 
969 	/* Setup input device */
970 	input->name = "ILI210x Touchscreen";
971 	input->id.bustype = BUS_I2C;
972 
973 	/* Multi touch */
974 	max_xy = (chip->resolution ?: SZ_64K) - 1;
975 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
976 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
977 	if (priv->chip->has_pressure_reg)
978 		input_set_abs_params(input, ABS_MT_PRESSURE, 0, 0xa, 0, 0);
979 	error = ili251x_firmware_update_cached_state(dev);
980 	if (error) {
981 		dev_err(dev, "Unable to cache firmware information, err: %d\n",
982 			error);
983 		return error;
984 	}
985 	touchscreen_parse_properties(input, true, &priv->prop);
986 
987 	error = input_mt_init_slots(input, priv->chip->max_touches,
988 				    INPUT_MT_DIRECT);
989 	if (error) {
990 		dev_err(dev, "Unable to set up slots, err: %d\n", error);
991 		return error;
992 	}
993 
994 	error = devm_request_threaded_irq(dev, client->irq, NULL, ili210x_irq,
995 					  IRQF_ONESHOT, client->name, priv);
996 	if (error) {
997 		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
998 			error);
999 		return error;
1000 	}
1001 
1002 	error = devm_add_action_or_reset(dev, ili210x_stop, priv);
1003 	if (error)
1004 		return error;
1005 
1006 	error = devm_device_add_group(dev, &ili210x_attr_group);
1007 	if (error) {
1008 		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
1009 			error);
1010 		return error;
1011 	}
1012 
1013 	error = input_register_device(priv->input);
1014 	if (error) {
1015 		dev_err(dev, "Cannot register input device, err: %d\n", error);
1016 		return error;
1017 	}
1018 
1019 	return 0;
1020 }
1021 
1022 static const struct i2c_device_id ili210x_i2c_id[] = {
1023 	{ "ili210x", (long)&ili210x_chip },
1024 	{ "ili2117", (long)&ili211x_chip },
1025 	{ "ili2120", (long)&ili212x_chip },
1026 	{ "ili251x", (long)&ili251x_chip },
1027 	{ }
1028 };
1029 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
1030 
1031 static const struct of_device_id ili210x_dt_ids[] = {
1032 	{ .compatible = "ilitek,ili210x", .data = &ili210x_chip },
1033 	{ .compatible = "ilitek,ili2117", .data = &ili211x_chip },
1034 	{ .compatible = "ilitek,ili2120", .data = &ili212x_chip },
1035 	{ .compatible = "ilitek,ili251x", .data = &ili251x_chip },
1036 	{ }
1037 };
1038 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
1039 
1040 static struct i2c_driver ili210x_ts_driver = {
1041 	.driver = {
1042 		.name = "ili210x_i2c",
1043 		.of_match_table = ili210x_dt_ids,
1044 	},
1045 	.id_table = ili210x_i2c_id,
1046 	.probe_new = ili210x_i2c_probe,
1047 };
1048 
1049 module_i2c_driver(ili210x_ts_driver);
1050 
1051 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
1052 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
1053 MODULE_LICENSE("GPL");
1054