1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Azoteq IQS550/572/525 Trackpad/Touchscreen Controller
4 *
5 * Copyright (C) 2018 Jeff LaBundy <jeff@labundy.com>
6 *
7 * These devices require firmware exported from a PC-based configuration tool
8 * made available by the vendor. Firmware files may be pushed to the device's
9 * nonvolatile memory by writing the filename to the 'fw_file' sysfs control.
10 *
11 * Link to PC-based configuration tool and datasheet: https://www.azoteq.com/
12 */
13
14#include <linux/bits.h>
15#include <linux/delay.h>
16#include <linux/device.h>
17#include <linux/err.h>
18#include <linux/firmware.h>
19#include <linux/gpio/consumer.h>
20#include <linux/i2c.h>
21#include <linux/input.h>
22#include <linux/input/mt.h>
23#include <linux/input/touchscreen.h>
24#include <linux/interrupt.h>
25#include <linux/kernel.h>
26#include <linux/mod_devicetable.h>
27#include <linux/module.h>
28#include <linux/slab.h>
29#include <asm/unaligned.h>
30
31#define IQS5XX_FW_FILE_LEN	64
32#define IQS5XX_NUM_RETRIES	10
33#define IQS5XX_NUM_CONTACTS	5
34#define IQS5XX_WR_BYTES_MAX	2
35
36#define IQS5XX_PROD_NUM_IQS550	40
37#define IQS5XX_PROD_NUM_IQS572	58
38#define IQS5XX_PROD_NUM_IQS525	52
39
40#define IQS5XX_SHOW_RESET	BIT(7)
41#define IQS5XX_ACK_RESET	BIT(7)
42
43#define IQS5XX_SUSPEND		BIT(0)
44#define IQS5XX_RESUME		0
45
46#define IQS5XX_SETUP_COMPLETE	BIT(6)
47#define IQS5XX_WDT		BIT(5)
48#define IQS5XX_ALP_REATI	BIT(3)
49#define IQS5XX_REATI		BIT(2)
50
51#define IQS5XX_TP_EVENT		BIT(2)
52#define IQS5XX_EVENT_MODE	BIT(0)
53
54#define IQS5XX_PROD_NUM		0x0000
55#define IQS5XX_SYS_INFO0	0x000F
56#define IQS5XX_SYS_INFO1	0x0010
57#define IQS5XX_SYS_CTRL0	0x0431
58#define IQS5XX_SYS_CTRL1	0x0432
59#define IQS5XX_SYS_CFG0		0x058E
60#define IQS5XX_SYS_CFG1		0x058F
61#define IQS5XX_X_RES		0x066E
62#define IQS5XX_Y_RES		0x0670
63#define IQS5XX_EXP_FILE		0x0677
64#define IQS5XX_CHKSM		0x83C0
65#define IQS5XX_APP		0x8400
66#define IQS5XX_CSTM		0xBE00
67#define IQS5XX_PMAP_END		0xBFFF
68#define IQS5XX_END_COMM		0xEEEE
69
70#define IQS5XX_CHKSM_LEN	(IQS5XX_APP - IQS5XX_CHKSM)
71#define IQS5XX_APP_LEN		(IQS5XX_CSTM - IQS5XX_APP)
72#define IQS5XX_CSTM_LEN		(IQS5XX_PMAP_END + 1 - IQS5XX_CSTM)
73#define IQS5XX_PMAP_LEN		(IQS5XX_PMAP_END + 1 - IQS5XX_CHKSM)
74
75#define IQS5XX_REC_HDR_LEN	4
76#define IQS5XX_REC_LEN_MAX	255
77#define IQS5XX_REC_TYPE_DATA	0x00
78#define IQS5XX_REC_TYPE_EOF	0x01
79
80#define IQS5XX_BL_ADDR_MASK	0x40
81#define IQS5XX_BL_CMD_VER	0x00
82#define IQS5XX_BL_CMD_READ	0x01
83#define IQS5XX_BL_CMD_EXEC	0x02
84#define IQS5XX_BL_CMD_CRC	0x03
85#define IQS5XX_BL_BLK_LEN_MAX	64
86#define IQS5XX_BL_ID		0x0200
87#define IQS5XX_BL_STATUS_NONE	0xEE
88#define IQS5XX_BL_CRC_PASS	0x00
89#define IQS5XX_BL_CRC_FAIL	0x01
90#define IQS5XX_BL_ATTEMPTS	3
91
92struct iqs5xx_dev_id_info {
93	__be16 prod_num;
94	__be16 proj_num;
95	u8 major_ver;
96	u8 minor_ver;
97	u8 bl_status;
98} __packed;
99
100struct iqs5xx_ihex_rec {
101	char start;
102	char len[2];
103	char addr[4];
104	char type[2];
105	char data[2];
106} __packed;
107
108struct iqs5xx_touch_data {
109	__be16 abs_x;
110	__be16 abs_y;
111	__be16 strength;
112	u8 area;
113} __packed;
114
115struct iqs5xx_status {
116	u8 sys_info[2];
117	u8 num_active;
118	__be16 rel_x;
119	__be16 rel_y;
120	struct iqs5xx_touch_data touch_data[IQS5XX_NUM_CONTACTS];
121} __packed;
122
123struct iqs5xx_private {
124	struct i2c_client *client;
125	struct input_dev *input;
126	struct gpio_desc *reset_gpio;
127	struct touchscreen_properties prop;
128	struct mutex lock;
129	struct iqs5xx_dev_id_info dev_id_info;
130	u8 exp_file[2];
131};
132
133static int iqs5xx_read_burst(struct i2c_client *client,
134			     u16 reg, void *val, u16 len)
135{
136	__be16 reg_buf = cpu_to_be16(reg);
137	int ret, i;
138	struct i2c_msg msg[] = {
139		{
140			.addr = client->addr,
141			.flags = 0,
142			.len = sizeof(reg_buf),
143			.buf = (u8 *)&reg_buf,
144		},
145		{
146			.addr = client->addr,
147			.flags = I2C_M_RD,
148			.len = len,
149			.buf = (u8 *)val,
150		},
151	};
152
153	/*
154	 * The first addressing attempt outside of a communication window fails
155	 * and must be retried, after which the device clock stretches until it
156	 * is available.
157	 */
158	for (i = 0; i < IQS5XX_NUM_RETRIES; i++) {
159		ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
160		if (ret == ARRAY_SIZE(msg))
161			return 0;
162
163		usleep_range(200, 300);
164	}
165
166	if (ret >= 0)
167		ret = -EIO;
168
169	dev_err(&client->dev, "Failed to read from address 0x%04X: %d\n",
170		reg, ret);
171
172	return ret;
173}
174
175static int iqs5xx_read_word(struct i2c_client *client, u16 reg, u16 *val)
176{
177	__be16 val_buf;
178	int error;
179
180	error = iqs5xx_read_burst(client, reg, &val_buf, sizeof(val_buf));
181	if (error)
182		return error;
183
184	*val = be16_to_cpu(val_buf);
185
186	return 0;
187}
188
189static int iqs5xx_write_burst(struct i2c_client *client,
190			      u16 reg, const void *val, u16 len)
191{
192	int ret, i;
193	u16 mlen = sizeof(reg) + len;
194	u8 mbuf[sizeof(reg) + IQS5XX_WR_BYTES_MAX];
195
196	if (len > IQS5XX_WR_BYTES_MAX)
197		return -EINVAL;
198
199	put_unaligned_be16(reg, mbuf);
200	memcpy(mbuf + sizeof(reg), val, len);
201
202	/*
203	 * The first addressing attempt outside of a communication window fails
204	 * and must be retried, after which the device clock stretches until it
205	 * is available.
206	 */
207	for (i = 0; i < IQS5XX_NUM_RETRIES; i++) {
208		ret = i2c_master_send(client, mbuf, mlen);
209		if (ret == mlen)
210			return 0;
211
212		usleep_range(200, 300);
213	}
214
215	if (ret >= 0)
216		ret = -EIO;
217
218	dev_err(&client->dev, "Failed to write to address 0x%04X: %d\n",
219		reg, ret);
220
221	return ret;
222}
223
224static int iqs5xx_write_word(struct i2c_client *client, u16 reg, u16 val)
225{
226	__be16 val_buf = cpu_to_be16(val);
227
228	return iqs5xx_write_burst(client, reg, &val_buf, sizeof(val_buf));
229}
230
231static int iqs5xx_write_byte(struct i2c_client *client, u16 reg, u8 val)
232{
233	return iqs5xx_write_burst(client, reg, &val, sizeof(val));
234}
235
236static void iqs5xx_reset(struct i2c_client *client)
237{
238	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
239
240	gpiod_set_value_cansleep(iqs5xx->reset_gpio, 1);
241	usleep_range(200, 300);
242
243	gpiod_set_value_cansleep(iqs5xx->reset_gpio, 0);
244}
245
246static int iqs5xx_bl_cmd(struct i2c_client *client, u8 bl_cmd, u16 bl_addr)
247{
248	struct i2c_msg msg;
249	int ret;
250	u8 mbuf[sizeof(bl_cmd) + sizeof(bl_addr)];
251
252	msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
253	msg.flags = 0;
254	msg.len = sizeof(bl_cmd);
255	msg.buf = mbuf;
256
257	*mbuf = bl_cmd;
258
259	switch (bl_cmd) {
260	case IQS5XX_BL_CMD_VER:
261	case IQS5XX_BL_CMD_CRC:
262	case IQS5XX_BL_CMD_EXEC:
263		break;
264	case IQS5XX_BL_CMD_READ:
265		msg.len += sizeof(bl_addr);
266		put_unaligned_be16(bl_addr, mbuf + sizeof(bl_cmd));
267		break;
268	default:
269		return -EINVAL;
270	}
271
272	ret = i2c_transfer(client->adapter, &msg, 1);
273	if (ret != 1)
274		goto msg_fail;
275
276	switch (bl_cmd) {
277	case IQS5XX_BL_CMD_VER:
278		msg.len = sizeof(u16);
279		break;
280	case IQS5XX_BL_CMD_CRC:
281		msg.len = sizeof(u8);
282		/*
283		 * This delay saves the bus controller the trouble of having to
284		 * tolerate a relatively long clock-stretching period while the
285		 * CRC is calculated.
286		 */
287		msleep(50);
288		break;
289	case IQS5XX_BL_CMD_EXEC:
290		usleep_range(10000, 10100);
291		fallthrough;
292	default:
293		return 0;
294	}
295
296	msg.flags = I2C_M_RD;
297
298	ret = i2c_transfer(client->adapter, &msg, 1);
299	if (ret != 1)
300		goto msg_fail;
301
302	if (bl_cmd == IQS5XX_BL_CMD_VER &&
303	    get_unaligned_be16(mbuf) != IQS5XX_BL_ID) {
304		dev_err(&client->dev, "Unrecognized bootloader ID: 0x%04X\n",
305			get_unaligned_be16(mbuf));
306		return -EINVAL;
307	}
308
309	if (bl_cmd == IQS5XX_BL_CMD_CRC && *mbuf != IQS5XX_BL_CRC_PASS) {
310		dev_err(&client->dev, "Bootloader CRC failed\n");
311		return -EIO;
312	}
313
314	return 0;
315
316msg_fail:
317	if (ret >= 0)
318		ret = -EIO;
319
320	if (bl_cmd != IQS5XX_BL_CMD_VER)
321		dev_err(&client->dev,
322			"Unsuccessful bootloader command 0x%02X: %d\n",
323			bl_cmd, ret);
324
325	return ret;
326}
327
328static int iqs5xx_bl_open(struct i2c_client *client)
329{
330	int error, i, j;
331
332	/*
333	 * The device opens a bootloader polling window for 2 ms following the
334	 * release of reset. If the host cannot establish communication during
335	 * this time frame, it must cycle reset again.
336	 */
337	for (i = 0; i < IQS5XX_BL_ATTEMPTS; i++) {
338		iqs5xx_reset(client);
339		usleep_range(350, 400);
340
341		for (j = 0; j < IQS5XX_NUM_RETRIES; j++) {
342			error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_VER, 0);
343			if (!error)
344				usleep_range(10000, 10100);
345			else if (error != -EINVAL)
346				continue;
347
348			return error;
349		}
350	}
351
352	dev_err(&client->dev, "Failed to open bootloader: %d\n", error);
353
354	return error;
355}
356
357static int iqs5xx_bl_write(struct i2c_client *client,
358			   u16 bl_addr, u8 *pmap_data, u16 pmap_len)
359{
360	struct i2c_msg msg;
361	int ret, i;
362	u8 mbuf[sizeof(bl_addr) + IQS5XX_BL_BLK_LEN_MAX];
363
364	if (pmap_len % IQS5XX_BL_BLK_LEN_MAX)
365		return -EINVAL;
366
367	msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
368	msg.flags = 0;
369	msg.len = sizeof(mbuf);
370	msg.buf = mbuf;
371
372	for (i = 0; i < pmap_len; i += IQS5XX_BL_BLK_LEN_MAX) {
373		put_unaligned_be16(bl_addr + i, mbuf);
374		memcpy(mbuf + sizeof(bl_addr), pmap_data + i,
375		       sizeof(mbuf) - sizeof(bl_addr));
376
377		ret = i2c_transfer(client->adapter, &msg, 1);
378		if (ret != 1)
379			goto msg_fail;
380
381		usleep_range(10000, 10100);
382	}
383
384	return 0;
385
386msg_fail:
387	if (ret >= 0)
388		ret = -EIO;
389
390	dev_err(&client->dev, "Failed to write block at address 0x%04X: %d\n",
391		bl_addr + i, ret);
392
393	return ret;
394}
395
396static int iqs5xx_bl_verify(struct i2c_client *client,
397			    u16 bl_addr, u8 *pmap_data, u16 pmap_len)
398{
399	struct i2c_msg msg;
400	int ret, i;
401	u8 bl_data[IQS5XX_BL_BLK_LEN_MAX];
402
403	if (pmap_len % IQS5XX_BL_BLK_LEN_MAX)
404		return -EINVAL;
405
406	msg.addr = client->addr ^ IQS5XX_BL_ADDR_MASK;
407	msg.flags = I2C_M_RD;
408	msg.len = sizeof(bl_data);
409	msg.buf = bl_data;
410
411	for (i = 0; i < pmap_len; i += IQS5XX_BL_BLK_LEN_MAX) {
412		ret = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_READ, bl_addr + i);
413		if (ret)
414			return ret;
415
416		ret = i2c_transfer(client->adapter, &msg, 1);
417		if (ret != 1)
418			goto msg_fail;
419
420		if (memcmp(bl_data, pmap_data + i, sizeof(bl_data))) {
421			dev_err(&client->dev,
422				"Failed to verify block at address 0x%04X\n",
423				bl_addr + i);
424			return -EIO;
425		}
426	}
427
428	return 0;
429
430msg_fail:
431	if (ret >= 0)
432		ret = -EIO;
433
434	dev_err(&client->dev, "Failed to read block at address 0x%04X: %d\n",
435		bl_addr + i, ret);
436
437	return ret;
438}
439
440static int iqs5xx_set_state(struct i2c_client *client, u8 state)
441{
442	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
443	int error1, error2;
444
445	if (!iqs5xx->dev_id_info.bl_status)
446		return 0;
447
448	mutex_lock(&iqs5xx->lock);
449
450	/*
451	 * Addressing the device outside of a communication window prompts it
452	 * to assert the RDY output, so disable the interrupt line to prevent
453	 * the handler from servicing a false interrupt.
454	 */
455	disable_irq(client->irq);
456
457	error1 = iqs5xx_write_byte(client, IQS5XX_SYS_CTRL1, state);
458	error2 = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
459
460	usleep_range(50, 100);
461	enable_irq(client->irq);
462
463	mutex_unlock(&iqs5xx->lock);
464
465	if (error1)
466		return error1;
467
468	return error2;
469}
470
471static int iqs5xx_open(struct input_dev *input)
472{
473	struct iqs5xx_private *iqs5xx = input_get_drvdata(input);
474
475	return iqs5xx_set_state(iqs5xx->client, IQS5XX_RESUME);
476}
477
478static void iqs5xx_close(struct input_dev *input)
479{
480	struct iqs5xx_private *iqs5xx = input_get_drvdata(input);
481
482	iqs5xx_set_state(iqs5xx->client, IQS5XX_SUSPEND);
483}
484
485static int iqs5xx_axis_init(struct i2c_client *client)
486{
487	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
488	struct touchscreen_properties *prop = &iqs5xx->prop;
489	struct input_dev *input = iqs5xx->input;
490	u16 max_x, max_y;
491	int error;
492
493	if (!input) {
494		input = devm_input_allocate_device(&client->dev);
495		if (!input)
496			return -ENOMEM;
497
498		input->name = client->name;
499		input->id.bustype = BUS_I2C;
500		input->open = iqs5xx_open;
501		input->close = iqs5xx_close;
502
503		input_set_drvdata(input, iqs5xx);
504		iqs5xx->input = input;
505	}
506
507	error = iqs5xx_read_word(client, IQS5XX_X_RES, &max_x);
508	if (error)
509		return error;
510
511	error = iqs5xx_read_word(client, IQS5XX_Y_RES, &max_y);
512	if (error)
513		return error;
514
515	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
516	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
517	input_set_abs_params(input, ABS_MT_PRESSURE, 0, U16_MAX, 0, 0);
518
519	touchscreen_parse_properties(input, true, prop);
520
521	/*
522	 * The device reserves 0xFFFF for coordinates that correspond to slots
523	 * which are not in a state of touch.
524	 */
525	if (prop->max_x >= U16_MAX || prop->max_y >= U16_MAX) {
526		dev_err(&client->dev, "Invalid touchscreen size: %u*%u\n",
527			prop->max_x, prop->max_y);
528		return -EINVAL;
529	}
530
531	if (prop->max_x != max_x) {
532		error = iqs5xx_write_word(client, IQS5XX_X_RES, prop->max_x);
533		if (error)
534			return error;
535	}
536
537	if (prop->max_y != max_y) {
538		error = iqs5xx_write_word(client, IQS5XX_Y_RES, prop->max_y);
539		if (error)
540			return error;
541	}
542
543	error = input_mt_init_slots(input, IQS5XX_NUM_CONTACTS,
544				    INPUT_MT_DIRECT);
545	if (error)
546		dev_err(&client->dev, "Failed to initialize slots: %d\n",
547			error);
548
549	return error;
550}
551
552static int iqs5xx_dev_init(struct i2c_client *client)
553{
554	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
555	struct iqs5xx_dev_id_info *dev_id_info;
556	int error;
557	u8 buf[sizeof(*dev_id_info) + 1];
558
559	error = iqs5xx_read_burst(client, IQS5XX_PROD_NUM,
560				  &buf[1], sizeof(*dev_id_info));
561	if (error)
562		return iqs5xx_bl_open(client);
563
564	/*
565	 * A000 and B000 devices use 8-bit and 16-bit addressing, respectively.
566	 * Querying an A000 device's version information with 16-bit addressing
567	 * gives the appearance that the data is shifted by one byte; a nonzero
568	 * leading array element suggests this could be the case (in which case
569	 * the missing zero is prepended).
570	 */
571	buf[0] = 0;
572	dev_id_info = (struct iqs5xx_dev_id_info *)&buf[buf[1] ? 0 : 1];
573
574	switch (be16_to_cpu(dev_id_info->prod_num)) {
575	case IQS5XX_PROD_NUM_IQS550:
576	case IQS5XX_PROD_NUM_IQS572:
577	case IQS5XX_PROD_NUM_IQS525:
578		break;
579	default:
580		dev_err(&client->dev, "Unrecognized product number: %u\n",
581			be16_to_cpu(dev_id_info->prod_num));
582		return -EINVAL;
583	}
584
585	/*
586	 * With the product number recognized yet shifted by one byte, open the
587	 * bootloader and wait for user space to convert the A000 device into a
588	 * B000 device via new firmware.
589	 */
590	if (buf[1]) {
591		dev_err(&client->dev, "Opening bootloader for A000 device\n");
592		return iqs5xx_bl_open(client);
593	}
594
595	error = iqs5xx_read_burst(client, IQS5XX_EXP_FILE,
596				  iqs5xx->exp_file, sizeof(iqs5xx->exp_file));
597	if (error)
598		return error;
599
600	error = iqs5xx_axis_init(client);
601	if (error)
602		return error;
603
604	error = iqs5xx_write_byte(client, IQS5XX_SYS_CTRL0, IQS5XX_ACK_RESET);
605	if (error)
606		return error;
607
608	error = iqs5xx_write_byte(client, IQS5XX_SYS_CFG0,
609				  IQS5XX_SETUP_COMPLETE | IQS5XX_WDT |
610				  IQS5XX_ALP_REATI | IQS5XX_REATI);
611	if (error)
612		return error;
613
614	error = iqs5xx_write_byte(client, IQS5XX_SYS_CFG1,
615				  IQS5XX_TP_EVENT | IQS5XX_EVENT_MODE);
616	if (error)
617		return error;
618
619	error = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
620	if (error)
621		return error;
622
623	iqs5xx->dev_id_info = *dev_id_info;
624
625	/*
626	 * The following delay allows ATI to complete before the open and close
627	 * callbacks are free to elicit I2C communication. Any attempts to read
628	 * from or write to the device during this time may face extended clock
629	 * stretching and prompt the I2C controller to report an error.
630	 */
631	msleep(250);
632
633	return 0;
634}
635
636static irqreturn_t iqs5xx_irq(int irq, void *data)
637{
638	struct iqs5xx_private *iqs5xx = data;
639	struct iqs5xx_status status;
640	struct i2c_client *client = iqs5xx->client;
641	struct input_dev *input = iqs5xx->input;
642	int error, i;
643
644	/*
645	 * This check is purely a precaution, as the device does not assert the
646	 * RDY output during bootloader mode. If the device operates outside of
647	 * bootloader mode, the input device is guaranteed to be allocated.
648	 */
649	if (!iqs5xx->dev_id_info.bl_status)
650		return IRQ_NONE;
651
652	error = iqs5xx_read_burst(client, IQS5XX_SYS_INFO0,
653				  &status, sizeof(status));
654	if (error)
655		return IRQ_NONE;
656
657	if (status.sys_info[0] & IQS5XX_SHOW_RESET) {
658		dev_err(&client->dev, "Unexpected device reset\n");
659
660		error = iqs5xx_dev_init(client);
661		if (error) {
662			dev_err(&client->dev,
663				"Failed to re-initialize device: %d\n", error);
664			return IRQ_NONE;
665		}
666
667		return IRQ_HANDLED;
668	}
669
670	for (i = 0; i < ARRAY_SIZE(status.touch_data); i++) {
671		struct iqs5xx_touch_data *touch_data = &status.touch_data[i];
672		u16 pressure = be16_to_cpu(touch_data->strength);
673
674		input_mt_slot(input, i);
675		if (input_mt_report_slot_state(input, MT_TOOL_FINGER,
676					       pressure != 0)) {
677			touchscreen_report_pos(input, &iqs5xx->prop,
678					       be16_to_cpu(touch_data->abs_x),
679					       be16_to_cpu(touch_data->abs_y),
680					       true);
681			input_report_abs(input, ABS_MT_PRESSURE, pressure);
682		}
683	}
684
685	input_mt_sync_frame(input);
686	input_sync(input);
687
688	error = iqs5xx_write_byte(client, IQS5XX_END_COMM, 0);
689	if (error)
690		return IRQ_NONE;
691
692	/*
693	 * Once the communication window is closed, a small delay is added to
694	 * ensure the device's RDY output has been deasserted by the time the
695	 * interrupt handler returns.
696	 */
697	usleep_range(50, 100);
698
699	return IRQ_HANDLED;
700}
701
702static int iqs5xx_fw_file_parse(struct i2c_client *client,
703				const char *fw_file, u8 *pmap)
704{
705	const struct firmware *fw;
706	struct iqs5xx_ihex_rec *rec;
707	size_t pos = 0;
708	int error, i;
709	u16 rec_num = 1;
710	u16 rec_addr;
711	u8 rec_len, rec_type, rec_chksm, chksm;
712	u8 rec_hdr[IQS5XX_REC_HDR_LEN];
713	u8 rec_data[IQS5XX_REC_LEN_MAX];
714
715	/*
716	 * Firmware exported from the vendor's configuration tool deviates from
717	 * standard ihex as follows: (1) the checksum for records corresponding
718	 * to user-exported settings is not recalculated, and (2) an address of
719	 * 0xFFFF is used for the EOF record.
720	 *
721	 * Because the ihex2fw tool tolerates neither (1) nor (2), the slightly
722	 * nonstandard ihex firmware is parsed directly by the driver.
723	 */
724	error = request_firmware(&fw, fw_file, &client->dev);
725	if (error) {
726		dev_err(&client->dev, "Failed to request firmware %s: %d\n",
727			fw_file, error);
728		return error;
729	}
730
731	do {
732		if (pos + sizeof(*rec) > fw->size) {
733			dev_err(&client->dev, "Insufficient firmware size\n");
734			error = -EINVAL;
735			break;
736		}
737		rec = (struct iqs5xx_ihex_rec *)(fw->data + pos);
738		pos += sizeof(*rec);
739
740		if (rec->start != ':') {
741			dev_err(&client->dev, "Invalid start at record %u\n",
742				rec_num);
743			error = -EINVAL;
744			break;
745		}
746
747		error = hex2bin(rec_hdr, rec->len, sizeof(rec_hdr));
748		if (error) {
749			dev_err(&client->dev, "Invalid header at record %u\n",
750				rec_num);
751			break;
752		}
753
754		rec_len = *rec_hdr;
755		rec_addr = get_unaligned_be16(rec_hdr + sizeof(rec_len));
756		rec_type = *(rec_hdr + sizeof(rec_len) + sizeof(rec_addr));
757
758		if (pos + rec_len * 2 > fw->size) {
759			dev_err(&client->dev, "Insufficient firmware size\n");
760			error = -EINVAL;
761			break;
762		}
763		pos += (rec_len * 2);
764
765		error = hex2bin(rec_data, rec->data, rec_len);
766		if (error) {
767			dev_err(&client->dev, "Invalid data at record %u\n",
768				rec_num);
769			break;
770		}
771
772		error = hex2bin(&rec_chksm,
773				rec->data + rec_len * 2, sizeof(rec_chksm));
774		if (error) {
775			dev_err(&client->dev, "Invalid checksum at record %u\n",
776				rec_num);
777			break;
778		}
779
780		chksm = 0;
781		for (i = 0; i < sizeof(rec_hdr); i++)
782			chksm += rec_hdr[i];
783		for (i = 0; i < rec_len; i++)
784			chksm += rec_data[i];
785		chksm = ~chksm + 1;
786
787		if (chksm != rec_chksm && rec_addr < IQS5XX_CSTM) {
788			dev_err(&client->dev,
789				"Incorrect checksum at record %u\n",
790				rec_num);
791			error = -EINVAL;
792			break;
793		}
794
795		switch (rec_type) {
796		case IQS5XX_REC_TYPE_DATA:
797			if (rec_addr < IQS5XX_CHKSM ||
798			    rec_addr > IQS5XX_PMAP_END) {
799				dev_err(&client->dev,
800					"Invalid address at record %u\n",
801					rec_num);
802				error = -EINVAL;
803			} else {
804				memcpy(pmap + rec_addr - IQS5XX_CHKSM,
805				       rec_data, rec_len);
806			}
807			break;
808		case IQS5XX_REC_TYPE_EOF:
809			break;
810		default:
811			dev_err(&client->dev, "Invalid type at record %u\n",
812				rec_num);
813			error = -EINVAL;
814		}
815
816		if (error)
817			break;
818
819		rec_num++;
820		while (pos < fw->size) {
821			if (*(fw->data + pos) == ':')
822				break;
823			pos++;
824		}
825	} while (rec_type != IQS5XX_REC_TYPE_EOF);
826
827	release_firmware(fw);
828
829	return error;
830}
831
832static int iqs5xx_fw_file_write(struct i2c_client *client, const char *fw_file)
833{
834	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
835	int error, error_init = 0;
836	u8 *pmap;
837
838	pmap = kzalloc(IQS5XX_PMAP_LEN, GFP_KERNEL);
839	if (!pmap)
840		return -ENOMEM;
841
842	error = iqs5xx_fw_file_parse(client, fw_file, pmap);
843	if (error)
844		goto err_kfree;
845
846	mutex_lock(&iqs5xx->lock);
847
848	/*
849	 * Disable the interrupt line in case the first attempt(s) to enter the
850	 * bootloader don't happen quickly enough, in which case the device may
851	 * assert the RDY output until the next attempt.
852	 */
853	disable_irq(client->irq);
854
855	iqs5xx->dev_id_info.bl_status = 0;
856
857	error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_VER, 0);
858	if (error) {
859		error = iqs5xx_bl_open(client);
860		if (error)
861			goto err_reset;
862	}
863
864	error = iqs5xx_bl_write(client, IQS5XX_CHKSM, pmap, IQS5XX_PMAP_LEN);
865	if (error)
866		goto err_reset;
867
868	error = iqs5xx_bl_cmd(client, IQS5XX_BL_CMD_CRC, 0);
869	if (error)
870		goto err_reset;
871
872	error = iqs5xx_bl_verify(client, IQS5XX_CSTM,
873				 pmap + IQS5XX_CHKSM_LEN + IQS5XX_APP_LEN,
874				 IQS5XX_CSTM_LEN);
875
876err_reset:
877	iqs5xx_reset(client);
878	usleep_range(15000, 15100);
879
880	error_init = iqs5xx_dev_init(client);
881	if (!iqs5xx->dev_id_info.bl_status)
882		error_init = error_init ? : -EINVAL;
883
884	enable_irq(client->irq);
885
886	mutex_unlock(&iqs5xx->lock);
887
888err_kfree:
889	kfree(pmap);
890
891	return error ? : error_init;
892}
893
894static ssize_t fw_file_store(struct device *dev,
895			     struct device_attribute *attr, const char *buf,
896			     size_t count)
897{
898	struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
899	struct i2c_client *client = iqs5xx->client;
900	size_t len = count;
901	bool input_reg = !iqs5xx->input;
902	char fw_file[IQS5XX_FW_FILE_LEN + 1];
903	int error;
904
905	if (!len)
906		return -EINVAL;
907
908	if (buf[len - 1] == '\n')
909		len--;
910
911	if (len > IQS5XX_FW_FILE_LEN)
912		return -ENAMETOOLONG;
913
914	memcpy(fw_file, buf, len);
915	fw_file[len] = '\0';
916
917	error = iqs5xx_fw_file_write(client, fw_file);
918	if (error)
919		return error;
920
921	/*
922	 * If the input device was not allocated already, it is guaranteed to
923	 * be allocated by this point and can finally be registered.
924	 */
925	if (input_reg) {
926		error = input_register_device(iqs5xx->input);
927		if (error) {
928			dev_err(&client->dev,
929				"Failed to register device: %d\n",
930				error);
931			return error;
932		}
933	}
934
935	return count;
936}
937
938static ssize_t fw_info_show(struct device *dev,
939			    struct device_attribute *attr, char *buf)
940{
941	struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
942
943	if (!iqs5xx->dev_id_info.bl_status)
944		return -ENODATA;
945
946	return sysfs_emit(buf, "%u.%u.%u.%u:%u.%u\n",
947			  be16_to_cpu(iqs5xx->dev_id_info.prod_num),
948			  be16_to_cpu(iqs5xx->dev_id_info.proj_num),
949			  iqs5xx->dev_id_info.major_ver,
950			  iqs5xx->dev_id_info.minor_ver,
951			  iqs5xx->exp_file[0], iqs5xx->exp_file[1]);
952}
953
954static DEVICE_ATTR_WO(fw_file);
955static DEVICE_ATTR_RO(fw_info);
956
957static struct attribute *iqs5xx_attrs[] = {
958	&dev_attr_fw_file.attr,
959	&dev_attr_fw_info.attr,
960	NULL,
961};
962
963static umode_t iqs5xx_attr_is_visible(struct kobject *kobj,
964				      struct attribute *attr, int i)
965{
966	struct device *dev = kobj_to_dev(kobj);
967	struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
968
969	if (attr == &dev_attr_fw_file.attr &&
970	    (iqs5xx->dev_id_info.bl_status == IQS5XX_BL_STATUS_NONE ||
971	    !iqs5xx->reset_gpio))
972		return 0;
973
974	return attr->mode;
975}
976
977static const struct attribute_group iqs5xx_group = {
978	.is_visible = iqs5xx_attr_is_visible,
979	.attrs = iqs5xx_attrs,
980};
981__ATTRIBUTE_GROUPS(iqs5xx);
982
983static int iqs5xx_suspend(struct device *dev)
984{
985	struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
986	struct input_dev *input = iqs5xx->input;
987	int error = 0;
988
989	if (!input || device_may_wakeup(dev))
990		return error;
991
992	mutex_lock(&input->mutex);
993
994	if (input_device_enabled(input))
995		error = iqs5xx_set_state(iqs5xx->client, IQS5XX_SUSPEND);
996
997	mutex_unlock(&input->mutex);
998
999	return error;
1000}
1001
1002static int iqs5xx_resume(struct device *dev)
1003{
1004	struct iqs5xx_private *iqs5xx = dev_get_drvdata(dev);
1005	struct input_dev *input = iqs5xx->input;
1006	int error = 0;
1007
1008	if (!input || device_may_wakeup(dev))
1009		return error;
1010
1011	mutex_lock(&input->mutex);
1012
1013	if (input_device_enabled(input))
1014		error = iqs5xx_set_state(iqs5xx->client, IQS5XX_RESUME);
1015
1016	mutex_unlock(&input->mutex);
1017
1018	return error;
1019}
1020
1021static DEFINE_SIMPLE_DEV_PM_OPS(iqs5xx_pm, iqs5xx_suspend, iqs5xx_resume);
1022
1023static int iqs5xx_probe(struct i2c_client *client)
1024{
1025	struct iqs5xx_private *iqs5xx;
1026	int error;
1027
1028	iqs5xx = devm_kzalloc(&client->dev, sizeof(*iqs5xx), GFP_KERNEL);
1029	if (!iqs5xx)
1030		return -ENOMEM;
1031
1032	i2c_set_clientdata(client, iqs5xx);
1033	iqs5xx->client = client;
1034
1035	iqs5xx->reset_gpio = devm_gpiod_get_optional(&client->dev,
1036						     "reset", GPIOD_OUT_LOW);
1037	if (IS_ERR(iqs5xx->reset_gpio)) {
1038		error = PTR_ERR(iqs5xx->reset_gpio);
1039		dev_err(&client->dev, "Failed to request GPIO: %d\n", error);
1040		return error;
1041	}
1042
1043	mutex_init(&iqs5xx->lock);
1044
1045	error = iqs5xx_dev_init(client);
1046	if (error)
1047		return error;
1048
1049	error = devm_request_threaded_irq(&client->dev, client->irq,
1050					  NULL, iqs5xx_irq, IRQF_ONESHOT,
1051					  client->name, iqs5xx);
1052	if (error) {
1053		dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
1054		return error;
1055	}
1056
1057	if (iqs5xx->input) {
1058		error = input_register_device(iqs5xx->input);
1059		if (error)
1060			dev_err(&client->dev,
1061				"Failed to register device: %d\n",
1062				error);
1063	}
1064
1065	return error;
1066}
1067
1068static const struct i2c_device_id iqs5xx_id[] = {
1069	{ "iqs550", 0 },
1070	{ "iqs572", 1 },
1071	{ "iqs525", 2 },
1072	{ }
1073};
1074MODULE_DEVICE_TABLE(i2c, iqs5xx_id);
1075
1076static const struct of_device_id iqs5xx_of_match[] = {
1077	{ .compatible = "azoteq,iqs550" },
1078	{ .compatible = "azoteq,iqs572" },
1079	{ .compatible = "azoteq,iqs525" },
1080	{ }
1081};
1082MODULE_DEVICE_TABLE(of, iqs5xx_of_match);
1083
1084static struct i2c_driver iqs5xx_i2c_driver = {
1085	.driver = {
1086		.name		= "iqs5xx",
1087		.dev_groups	= iqs5xx_groups,
1088		.of_match_table	= iqs5xx_of_match,
1089		.pm		= pm_sleep_ptr(&iqs5xx_pm),
1090	},
1091	.id_table	= iqs5xx_id,
1092	.probe		= iqs5xx_probe,
1093};
1094module_i2c_driver(iqs5xx_i2c_driver);
1095
1096MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
1097MODULE_DESCRIPTION("Azoteq IQS550/572/525 Trackpad/Touchscreen Controller");
1098MODULE_LICENSE("GPL");
1099