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/mod_devicetable.h>
12 #include <linux/module.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 		resx = le16_to_cpup((__le16 *)rs);
375 		resy = le16_to_cpup((__le16 *)(rs + 2));
376 
377 		/* The value reported by the firmware is invalid. */
378 		if (!resx || resx == 0xffff || !resy || resy == 0xffff)
379 			error = -EINVAL;
380 	}
381 
382 	/*
383 	 * In case of error, the firmware might be stuck in bootloader mode,
384 	 * e.g. after a failed firmware update. Set maximum resolution, but
385 	 * do not fail to probe, so the user can re-trigger the firmware
386 	 * update and recover the touch controller.
387 	 */
388 	if (error) {
389 		dev_warn(dev, "Invalid resolution reported by controller.\n");
390 		resx = 16384;
391 		resy = 16384;
392 	}
393 
394 	input_abs_set_max(priv->input, ABS_X, resx - 1);
395 	input_abs_set_max(priv->input, ABS_Y, resy - 1);
396 	input_abs_set_max(priv->input, ABS_MT_POSITION_X, resx - 1);
397 	input_abs_set_max(priv->input, ABS_MT_POSITION_Y, resy - 1);
398 
399 	return error;
400 }
401 
402 static ssize_t ili251x_firmware_update_firmware_version(struct device *dev)
403 {
404 	struct i2c_client *client = to_i2c_client(dev);
405 	struct ili210x *priv = i2c_get_clientdata(client);
406 	int error;
407 	u8 fw[8];
408 
409 	/* Get firmware version */
410 	error = priv->chip->read_reg(client, REG_FIRMWARE_VERSION,
411 				     &fw, sizeof(fw));
412 	if (!error)
413 		memcpy(priv->version_firmware, fw, sizeof(fw));
414 
415 	return error;
416 }
417 
418 static ssize_t ili251x_firmware_update_kernel_version(struct device *dev)
419 {
420 	struct i2c_client *client = to_i2c_client(dev);
421 	struct ili210x *priv = i2c_get_clientdata(client);
422 	int error;
423 	u8 kv[5];
424 
425 	/* Get kernel version */
426 	error = priv->chip->read_reg(client, REG_KERNEL_VERSION,
427 				     &kv, sizeof(kv));
428 	if (!error)
429 		memcpy(priv->version_kernel, kv, sizeof(kv));
430 
431 	return error;
432 }
433 
434 static ssize_t ili251x_firmware_update_protocol_version(struct device *dev)
435 {
436 	struct i2c_client *client = to_i2c_client(dev);
437 	struct ili210x *priv = i2c_get_clientdata(client);
438 	int error;
439 	u8 pv[2];
440 
441 	/* Get protocol version */
442 	error = priv->chip->read_reg(client, REG_PROTOCOL_VERSION,
443 				     &pv, sizeof(pv));
444 	if (!error)
445 		memcpy(priv->version_proto, pv, sizeof(pv));
446 
447 	return error;
448 }
449 
450 static ssize_t ili251x_firmware_update_ic_mode(struct device *dev)
451 {
452 	struct i2c_client *client = to_i2c_client(dev);
453 	struct ili210x *priv = i2c_get_clientdata(client);
454 	int error;
455 	u8 md[2];
456 
457 	/* Get chip boot mode */
458 	error = priv->chip->read_reg(client, REG_GET_MODE, &md, sizeof(md));
459 	if (!error)
460 		memcpy(priv->ic_mode, md, sizeof(md));
461 
462 	return error;
463 }
464 
465 static int ili251x_firmware_update_cached_state(struct device *dev)
466 {
467 	struct i2c_client *client = to_i2c_client(dev);
468 	struct ili210x *priv = i2c_get_clientdata(client);
469 	int error;
470 
471 	if (!priv->chip->has_firmware_proto)
472 		return 0;
473 
474 	/* Wait for firmware to boot and stabilize itself. */
475 	msleep(200);
476 
477 	/* Firmware does report valid information. */
478 	error = ili251x_firmware_update_resolution(dev);
479 	if (error)
480 		return error;
481 
482 	error = ili251x_firmware_update_firmware_version(dev);
483 	if (error)
484 		return error;
485 
486 	error = ili251x_firmware_update_kernel_version(dev);
487 	if (error)
488 		return error;
489 
490 	error = ili251x_firmware_update_protocol_version(dev);
491 	if (error)
492 		return error;
493 
494 	error = ili251x_firmware_update_ic_mode(dev);
495 	if (error)
496 		return error;
497 
498 	return 0;
499 }
500 
501 static ssize_t ili251x_firmware_version_show(struct device *dev,
502 					     struct device_attribute *attr,
503 					     char *buf)
504 {
505 	struct i2c_client *client = to_i2c_client(dev);
506 	struct ili210x *priv = i2c_get_clientdata(client);
507 	u8 *fw = priv->version_firmware;
508 
509 	return sysfs_emit(buf, "%02x%02x.%02x%02x.%02x%02x.%02x%02x\n",
510 			  fw[0], fw[1], fw[2], fw[3],
511 			  fw[4], fw[5], fw[6], fw[7]);
512 }
513 static DEVICE_ATTR(firmware_version, 0444, ili251x_firmware_version_show, NULL);
514 
515 static ssize_t ili251x_kernel_version_show(struct device *dev,
516 					   struct device_attribute *attr,
517 					   char *buf)
518 {
519 	struct i2c_client *client = to_i2c_client(dev);
520 	struct ili210x *priv = i2c_get_clientdata(client);
521 	u8 *kv = priv->version_kernel;
522 
523 	return sysfs_emit(buf, "%02x.%02x.%02x.%02x.%02x\n",
524 			  kv[0], kv[1], kv[2], kv[3], kv[4]);
525 }
526 static DEVICE_ATTR(kernel_version, 0444, ili251x_kernel_version_show, NULL);
527 
528 static ssize_t ili251x_protocol_version_show(struct device *dev,
529 					     struct device_attribute *attr,
530 					     char *buf)
531 {
532 	struct i2c_client *client = to_i2c_client(dev);
533 	struct ili210x *priv = i2c_get_clientdata(client);
534 	u8 *pv = priv->version_proto;
535 
536 	return sysfs_emit(buf, "%02x.%02x\n", pv[0], pv[1]);
537 }
538 static DEVICE_ATTR(protocol_version, 0444, ili251x_protocol_version_show, NULL);
539 
540 static ssize_t ili251x_mode_show(struct device *dev,
541 				 struct device_attribute *attr, char *buf)
542 {
543 	struct i2c_client *client = to_i2c_client(dev);
544 	struct ili210x *priv = i2c_get_clientdata(client);
545 	u8 *md = priv->ic_mode;
546 	char *mode = "AP";
547 
548 	if (md[0] == REG_GET_MODE_AP)		/* Application Mode */
549 		mode = "AP";
550 	else if (md[0] == REG_GET_MODE_BL)	/* BootLoader Mode */
551 		mode = "BL";
552 	else					/* Unknown Mode */
553 		mode = "??";
554 
555 	return sysfs_emit(buf, "%02x.%02x:%s\n", md[0], md[1], mode);
556 }
557 static DEVICE_ATTR(mode, 0444, ili251x_mode_show, NULL);
558 
559 static ssize_t ili210x_calibrate(struct device *dev,
560 				 struct device_attribute *attr,
561 				 const char *buf, size_t count)
562 {
563 	struct i2c_client *client = to_i2c_client(dev);
564 	struct ili210x *priv = i2c_get_clientdata(client);
565 	unsigned long calibrate;
566 	int rc;
567 	u8 cmd = REG_CALIBRATE;
568 
569 	if (kstrtoul(buf, 10, &calibrate))
570 		return -EINVAL;
571 
572 	if (calibrate > 1)
573 		return -EINVAL;
574 
575 	if (calibrate) {
576 		rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
577 		if (rc != sizeof(cmd))
578 			return -EIO;
579 	}
580 
581 	return count;
582 }
583 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
584 
585 static int ili251x_firmware_to_buffer(const struct firmware *fw,
586 				      u8 **buf, u16 *ac_end, u16 *df_end)
587 {
588 	const struct ihex_binrec *rec;
589 	u32 fw_addr, fw_last_addr = 0;
590 	u16 fw_len;
591 	u8 *fw_buf;
592 	int error;
593 
594 	/*
595 	 * The firmware ihex blob can never be bigger than 64 kiB, so make this
596 	 * simple -- allocate a 64 kiB buffer, iterate over the ihex blob records
597 	 * once, copy them all into this buffer at the right locations, and then
598 	 * do all operations on this linear buffer.
599 	 */
600 	fw_buf = kzalloc(SZ_64K, GFP_KERNEL);
601 	if (!fw_buf)
602 		return -ENOMEM;
603 
604 	rec = (const struct ihex_binrec *)fw->data;
605 	while (rec) {
606 		fw_addr = be32_to_cpu(rec->addr);
607 		fw_len = be16_to_cpu(rec->len);
608 
609 		/* The last 32 Byte firmware block can be 0xffe0 */
610 		if (fw_addr + fw_len > SZ_64K || fw_addr > SZ_64K - 32) {
611 			error = -EFBIG;
612 			goto err_big;
613 		}
614 
615 		/* Find the last address before DF start address, that is AC end */
616 		if (fw_addr == 0xf000)
617 			*ac_end = fw_last_addr;
618 		fw_last_addr = fw_addr + fw_len;
619 
620 		memcpy(fw_buf + fw_addr, rec->data, fw_len);
621 		rec = ihex_next_binrec(rec);
622 	}
623 
624 	/* DF end address is the last address in the firmware blob */
625 	*df_end = fw_addr + fw_len;
626 	*buf = fw_buf;
627 	return 0;
628 
629 err_big:
630 	kfree(fw_buf);
631 	return error;
632 }
633 
634 /* Switch mode between Application and BootLoader */
635 static int ili251x_switch_ic_mode(struct i2c_client *client, u8 cmd_mode)
636 {
637 	struct ili210x *priv = i2c_get_clientdata(client);
638 	u8 cmd_wren[3] = { REG_WRITE_ENABLE, 0x5a, 0xa5 };
639 	u8 md[2];
640 	int error;
641 
642 	error = priv->chip->read_reg(client, REG_GET_MODE, md, sizeof(md));
643 	if (error)
644 		return error;
645 	/* Mode already set */
646 	if ((cmd_mode == REG_SET_MODE_AP && md[0] == REG_GET_MODE_AP) ||
647 	    (cmd_mode == REG_SET_MODE_BL && md[0] == REG_GET_MODE_BL))
648 		return 0;
649 
650 	/* Unlock writes */
651 	error = i2c_master_send(client, cmd_wren, sizeof(cmd_wren));
652 	if (error != sizeof(cmd_wren))
653 		return -EINVAL;
654 
655 	mdelay(20);
656 
657 	/* Select mode (BootLoader or Application) */
658 	error = i2c_master_send(client, &cmd_mode, 1);
659 	if (error != 1)
660 		return -EINVAL;
661 
662 	mdelay(200);	/* Reboot into bootloader takes a lot of time ... */
663 
664 	/* Read back mode */
665 	error = priv->chip->read_reg(client, REG_GET_MODE, md, sizeof(md));
666 	if (error)
667 		return error;
668 	/* Check if mode is correct now. */
669 	if ((cmd_mode == REG_SET_MODE_AP && md[0] == REG_GET_MODE_AP) ||
670 	    (cmd_mode == REG_SET_MODE_BL && md[0] == REG_GET_MODE_BL))
671 		return 0;
672 
673 	return -EINVAL;
674 }
675 
676 static int ili251x_firmware_busy(struct i2c_client *client)
677 {
678 	struct ili210x *priv = i2c_get_clientdata(client);
679 	int error, i = 0;
680 	u8 data;
681 
682 	do {
683 		/* The read_reg already contains suitable delay */
684 		error = priv->chip->read_reg(client, REG_IC_BUSY, &data, 1);
685 		if (error)
686 			return error;
687 		if (i++ == 100000)
688 			return -ETIMEDOUT;
689 	} while (data != REG_IC_BUSY_NOT_BUSY);
690 
691 	return 0;
692 }
693 
694 static int ili251x_firmware_write_to_ic(struct device *dev, u8 *fwbuf,
695 					u16 start, u16 end, u8 dataflash)
696 {
697 	struct i2c_client *client = to_i2c_client(dev);
698 	struct ili210x *priv = i2c_get_clientdata(client);
699 	u8 cmd_crc = REG_READ_DATA_CRC;
700 	u8 crcrb[4] = { 0 };
701 	u8 fw_data[33];
702 	u16 fw_addr;
703 	int error;
704 
705 	/*
706 	 * The DF (dataflash) needs 2 bytes offset for unknown reasons,
707 	 * the AC (application) has 2 bytes CRC16-CCITT at the end.
708 	 */
709 	u16 crc = crc_ccitt(0, fwbuf + start + (dataflash ? 2 : 0),
710 			    end - start - 2);
711 
712 	/* Unlock write to either AC (application) or DF (dataflash) area */
713 	u8 cmd_wr[10] = {
714 		REG_WRITE_ENABLE, 0x5a, 0xa5, dataflash,
715 		(end >> 16) & 0xff, (end >> 8) & 0xff, end & 0xff,
716 		(crc >> 16) & 0xff, (crc >> 8) & 0xff, crc & 0xff
717 	};
718 
719 	error = i2c_master_send(client, cmd_wr, sizeof(cmd_wr));
720 	if (error != sizeof(cmd_wr))
721 		return -EINVAL;
722 
723 	error = ili251x_firmware_busy(client);
724 	if (error)
725 		return error;
726 
727 	for (fw_addr = start; fw_addr < end; fw_addr += 32) {
728 		fw_data[0] = REG_WRITE_DATA;
729 		memcpy(&(fw_data[1]), fwbuf + fw_addr, 32);
730 		error = i2c_master_send(client, fw_data, 33);
731 		if (error != sizeof(fw_data))
732 			return error;
733 		error = ili251x_firmware_busy(client);
734 		if (error)
735 			return error;
736 	}
737 
738 	error = i2c_master_send(client, &cmd_crc, 1);
739 	if (error != 1)
740 		return -EINVAL;
741 
742 	error = ili251x_firmware_busy(client);
743 	if (error)
744 		return error;
745 
746 	error = priv->chip->read_reg(client, REG_READ_DATA_CRC,
747 				   &crcrb, sizeof(crcrb));
748 	if (error)
749 		return error;
750 
751 	/* Check CRC readback */
752 	if ((crcrb[0] != (crc & 0xff)) || crcrb[1] != ((crc >> 8) & 0xff))
753 		return -EINVAL;
754 
755 	return 0;
756 }
757 
758 static int ili251x_firmware_reset(struct i2c_client *client)
759 {
760 	u8 cmd_reset[2] = { 0xf2, 0x01 };
761 	int error;
762 
763 	error = i2c_master_send(client, cmd_reset, sizeof(cmd_reset));
764 	if (error != sizeof(cmd_reset))
765 		return -EINVAL;
766 
767 	return ili251x_firmware_busy(client);
768 }
769 
770 static void ili210x_hardware_reset(struct gpio_desc *reset_gpio)
771 {
772 	/* Reset the controller */
773 	gpiod_set_value_cansleep(reset_gpio, 1);
774 	usleep_range(12000, 15000);
775 	gpiod_set_value_cansleep(reset_gpio, 0);
776 	msleep(300);
777 }
778 
779 static ssize_t ili210x_firmware_update_store(struct device *dev,
780 					     struct device_attribute *attr,
781 					     const char *buf, size_t count)
782 {
783 	struct i2c_client *client = to_i2c_client(dev);
784 	struct ili210x *priv = i2c_get_clientdata(client);
785 	const char *fwname = ILI251X_FW_FILENAME;
786 	const struct firmware *fw;
787 	u16 ac_end, df_end;
788 	u8 *fwbuf;
789 	int error;
790 	int i;
791 
792 	error = request_ihex_firmware(&fw, fwname, dev);
793 	if (error) {
794 		dev_err(dev, "Failed to request firmware %s, error=%d\n",
795 			fwname, error);
796 		return error;
797 	}
798 
799 	error = ili251x_firmware_to_buffer(fw, &fwbuf, &ac_end, &df_end);
800 	release_firmware(fw);
801 	if (error)
802 		return error;
803 
804 	/*
805 	 * Disable touchscreen IRQ, so that we would not get spurious touch
806 	 * interrupt during firmware update, and so that the IRQ handler won't
807 	 * trigger and interfere with the firmware update. There is no bit in
808 	 * the touch controller to disable the IRQs during update, so we have
809 	 * to do it this way here.
810 	 */
811 	disable_irq(client->irq);
812 
813 	dev_dbg(dev, "Firmware update started, firmware=%s\n", fwname);
814 
815 	ili210x_hardware_reset(priv->reset_gpio);
816 
817 	error = ili251x_firmware_reset(client);
818 	if (error)
819 		goto exit;
820 
821 	/* This may not succeed on first try, so re-try a few times. */
822 	for (i = 0; i < 5; i++) {
823 		error = ili251x_switch_ic_mode(client, REG_SET_MODE_BL);
824 		if (!error)
825 			break;
826 	}
827 
828 	if (error)
829 		goto exit;
830 
831 	dev_dbg(dev, "IC is now in BootLoader mode\n");
832 
833 	msleep(200);	/* The bootloader seems to need some time too. */
834 
835 	error = ili251x_firmware_write_to_ic(dev, fwbuf, 0xf000, df_end, 1);
836 	if (error) {
837 		dev_err(dev, "DF firmware update failed, error=%d\n", error);
838 		goto exit;
839 	}
840 
841 	dev_dbg(dev, "DataFlash firmware written\n");
842 
843 	error = ili251x_firmware_write_to_ic(dev, fwbuf, 0x2000, ac_end, 0);
844 	if (error) {
845 		dev_err(dev, "AC firmware update failed, error=%d\n", error);
846 		goto exit;
847 	}
848 
849 	dev_dbg(dev, "Application firmware written\n");
850 
851 	/* This may not succeed on first try, so re-try a few times. */
852 	for (i = 0; i < 5; i++) {
853 		error = ili251x_switch_ic_mode(client, REG_SET_MODE_AP);
854 		if (!error)
855 			break;
856 	}
857 
858 	if (error)
859 		goto exit;
860 
861 	dev_dbg(dev, "IC is now in Application mode\n");
862 
863 	error = ili251x_firmware_update_cached_state(dev);
864 	if (error)
865 		goto exit;
866 
867 	error = count;
868 
869 exit:
870 	ili210x_hardware_reset(priv->reset_gpio);
871 	dev_dbg(dev, "Firmware update ended, error=%i\n", error);
872 	enable_irq(client->irq);
873 	kfree(fwbuf);
874 	return error;
875 }
876 
877 static DEVICE_ATTR(firmware_update, 0200, NULL, ili210x_firmware_update_store);
878 
879 static struct attribute *ili210x_attributes[] = {
880 	&dev_attr_calibrate.attr,
881 	&dev_attr_firmware_update.attr,
882 	&dev_attr_firmware_version.attr,
883 	&dev_attr_kernel_version.attr,
884 	&dev_attr_protocol_version.attr,
885 	&dev_attr_mode.attr,
886 	NULL,
887 };
888 
889 static umode_t ili210x_attributes_visible(struct kobject *kobj,
890 					  struct attribute *attr, int index)
891 {
892 	struct device *dev = kobj_to_dev(kobj);
893 	struct i2c_client *client = to_i2c_client(dev);
894 	struct ili210x *priv = i2c_get_clientdata(client);
895 
896 	/* Calibrate is present on all ILI2xxx which have calibrate register */
897 	if (attr == &dev_attr_calibrate.attr)
898 		return priv->chip->has_calibrate_reg ? attr->mode : 0;
899 
900 	/* Firmware/Kernel/Protocol/BootMode is implememted only for ILI251x */
901 	if (!priv->chip->has_firmware_proto)
902 		return 0;
903 
904 	return attr->mode;
905 }
906 
907 static const struct attribute_group ili210x_attr_group = {
908 	.attrs = ili210x_attributes,
909 	.is_visible = ili210x_attributes_visible,
910 };
911 
912 static void ili210x_power_down(void *data)
913 {
914 	struct gpio_desc *reset_gpio = data;
915 
916 	gpiod_set_value_cansleep(reset_gpio, 1);
917 }
918 
919 static void ili210x_stop(void *data)
920 {
921 	struct ili210x *priv = data;
922 
923 	/* Tell ISR to quit even if there is a contact. */
924 	priv->stop = true;
925 }
926 
927 static int ili210x_i2c_probe(struct i2c_client *client)
928 {
929 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
930 	struct device *dev = &client->dev;
931 	const struct ili2xxx_chip *chip;
932 	struct ili210x *priv;
933 	struct gpio_desc *reset_gpio;
934 	struct input_dev *input;
935 	int error;
936 	unsigned int max_xy;
937 
938 	dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
939 
940 	chip = device_get_match_data(dev);
941 	if (!chip && id)
942 		chip = (const struct ili2xxx_chip *)id->driver_data;
943 	if (!chip) {
944 		dev_err(&client->dev, "unknown device model\n");
945 		return -ENODEV;
946 	}
947 
948 	if (client->irq <= 0) {
949 		dev_err(dev, "No IRQ!\n");
950 		return -EINVAL;
951 	}
952 
953 	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
954 	if (IS_ERR(reset_gpio))
955 		return PTR_ERR(reset_gpio);
956 
957 	if (reset_gpio) {
958 		error = devm_add_action_or_reset(dev, ili210x_power_down,
959 						 reset_gpio);
960 		if (error)
961 			return error;
962 
963 		ili210x_hardware_reset(reset_gpio);
964 	}
965 
966 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
967 	if (!priv)
968 		return -ENOMEM;
969 
970 	input = devm_input_allocate_device(dev);
971 	if (!input)
972 		return -ENOMEM;
973 
974 	priv->client = client;
975 	priv->input = input;
976 	priv->reset_gpio = reset_gpio;
977 	priv->chip = chip;
978 	i2c_set_clientdata(client, priv);
979 
980 	/* Setup input device */
981 	input->name = "ILI210x Touchscreen";
982 	input->id.bustype = BUS_I2C;
983 
984 	/* Multi touch */
985 	max_xy = (chip->resolution ?: SZ_64K) - 1;
986 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
987 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
988 	if (priv->chip->has_pressure_reg)
989 		input_set_abs_params(input, ABS_MT_PRESSURE, 0, 0xa, 0, 0);
990 	error = ili251x_firmware_update_cached_state(dev);
991 	if (error)
992 		dev_warn(dev, "Unable to cache firmware information, err: %d\n",
993 			 error);
994 
995 	touchscreen_parse_properties(input, true, &priv->prop);
996 
997 	error = input_mt_init_slots(input, priv->chip->max_touches,
998 				    INPUT_MT_DIRECT);
999 	if (error) {
1000 		dev_err(dev, "Unable to set up slots, err: %d\n", error);
1001 		return error;
1002 	}
1003 
1004 	error = devm_request_threaded_irq(dev, client->irq, NULL, ili210x_irq,
1005 					  IRQF_ONESHOT, client->name, priv);
1006 	if (error) {
1007 		dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
1008 			error);
1009 		return error;
1010 	}
1011 
1012 	error = devm_add_action_or_reset(dev, ili210x_stop, priv);
1013 	if (error)
1014 		return error;
1015 
1016 	error = devm_device_add_group(dev, &ili210x_attr_group);
1017 	if (error) {
1018 		dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
1019 			error);
1020 		return error;
1021 	}
1022 
1023 	error = input_register_device(priv->input);
1024 	if (error) {
1025 		dev_err(dev, "Cannot register input device, err: %d\n", error);
1026 		return error;
1027 	}
1028 
1029 	return 0;
1030 }
1031 
1032 static const struct i2c_device_id ili210x_i2c_id[] = {
1033 	{ "ili210x", (long)&ili210x_chip },
1034 	{ "ili2117", (long)&ili211x_chip },
1035 	{ "ili2120", (long)&ili212x_chip },
1036 	{ "ili251x", (long)&ili251x_chip },
1037 	{ }
1038 };
1039 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
1040 
1041 static const struct of_device_id ili210x_dt_ids[] = {
1042 	{ .compatible = "ilitek,ili210x", .data = &ili210x_chip },
1043 	{ .compatible = "ilitek,ili2117", .data = &ili211x_chip },
1044 	{ .compatible = "ilitek,ili2120", .data = &ili212x_chip },
1045 	{ .compatible = "ilitek,ili251x", .data = &ili251x_chip },
1046 	{ }
1047 };
1048 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
1049 
1050 static struct i2c_driver ili210x_ts_driver = {
1051 	.driver = {
1052 		.name = "ili210x_i2c",
1053 		.of_match_table = ili210x_dt_ids,
1054 	},
1055 	.id_table = ili210x_i2c_id,
1056 	.probe = ili210x_i2c_probe,
1057 };
1058 
1059 module_i2c_driver(ili210x_ts_driver);
1060 
1061 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
1062 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
1063 MODULE_LICENSE("GPL");
1064