xref: /openbmc/linux/drivers/nfc/pn544/i2c.c (revision bc000245)
1 /*
2  * I2C Link Layer for PN544 HCI based Driver
3  *
4  * Copyright (C) 2012  Intel Corporation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the
17  * Free Software Foundation, Inc.,
18  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/crc-ccitt.h>
24 #include <linux/module.h>
25 #include <linux/i2c.h>
26 #include <linux/gpio.h>
27 #include <linux/miscdevice.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <linux/nfc.h>
31 #include <linux/firmware.h>
32 #include <linux/unaligned/access_ok.h>
33 #include <linux/platform_data/pn544.h>
34 
35 #include <net/nfc/hci.h>
36 #include <net/nfc/llc.h>
37 #include <net/nfc/nfc.h>
38 
39 #include "pn544.h"
40 
41 #define PN544_I2C_FRAME_HEADROOM 1
42 #define PN544_I2C_FRAME_TAILROOM 2
43 
44 /* framing in HCI mode */
45 #define PN544_HCI_I2C_LLC_LEN		1
46 #define PN544_HCI_I2C_LLC_CRC		2
47 #define PN544_HCI_I2C_LLC_LEN_CRC	(PN544_HCI_I2C_LLC_LEN + \
48 					 PN544_HCI_I2C_LLC_CRC)
49 #define PN544_HCI_I2C_LLC_MIN_SIZE	(1 + PN544_HCI_I2C_LLC_LEN_CRC)
50 #define PN544_HCI_I2C_LLC_MAX_PAYLOAD	29
51 #define PN544_HCI_I2C_LLC_MAX_SIZE	(PN544_HCI_I2C_LLC_LEN_CRC + 1 + \
52 					 PN544_HCI_I2C_LLC_MAX_PAYLOAD)
53 
54 static struct i2c_device_id pn544_hci_i2c_id_table[] = {
55 	{"pn544", 0},
56 	{}
57 };
58 
59 MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);
60 
61 #define PN544_HCI_I2C_DRIVER_NAME "pn544_hci_i2c"
62 
63 #define PN544_FW_CMD_WRITE 0x08
64 #define PN544_FW_CMD_CHECK 0x06
65 
66 struct pn544_i2c_fw_frame_write {
67 	u8 cmd;
68 	u16 be_length;
69 	u8 be_dest_addr[3];
70 	u16 be_datalen;
71 	u8 data[];
72 } __packed;
73 
74 struct pn544_i2c_fw_frame_check {
75 	u8 cmd;
76 	u16 be_length;
77 	u8 be_start_addr[3];
78 	u16 be_datalen;
79 	u16 be_crc;
80 } __packed;
81 
82 struct pn544_i2c_fw_frame_response {
83 	u8 status;
84 	u16 be_length;
85 } __packed;
86 
87 struct pn544_i2c_fw_blob {
88 	u32 be_size;
89 	u32 be_destaddr;
90 	u8 data[];
91 };
92 
93 #define PN544_FW_CMD_RESULT_TIMEOUT 0x01
94 #define PN544_FW_CMD_RESULT_BAD_CRC 0x02
95 #define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
96 #define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
97 #define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
98 #define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
99 #define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
100 
101 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
102 
103 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
104 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
105 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
106 #define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
107 					 PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
108 					 PN544_FW_WRITE_BUFFER_MAX_LEN)
109 
110 #define FW_WORK_STATE_IDLE 1
111 #define FW_WORK_STATE_START 2
112 #define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
113 #define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
114 
115 struct pn544_i2c_phy {
116 	struct i2c_client *i2c_dev;
117 	struct nfc_hci_dev *hdev;
118 
119 	unsigned int gpio_en;
120 	unsigned int gpio_irq;
121 	unsigned int gpio_fw;
122 	unsigned int en_polarity;
123 
124 	struct work_struct fw_work;
125 	int fw_work_state;
126 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
127 	const struct firmware *fw;
128 	u32 fw_blob_dest_addr;
129 	size_t fw_blob_size;
130 	const u8 *fw_blob_data;
131 	size_t fw_written;
132 	int fw_cmd_result;
133 
134 	int powered;
135 	int run_mode;
136 
137 	int hard_fault;		/*
138 				 * < 0 if hardware error occured (e.g. i2c err)
139 				 * and prevents normal operation.
140 				 */
141 };
142 
143 #define I2C_DUMP_SKB(info, skb)					\
144 do {								\
145 	pr_debug("%s:\n", info);				\
146 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
147 		       16, 1, (skb)->data, (skb)->len, 0);	\
148 } while (0)
149 
150 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
151 {
152 	int polarity, retry, ret;
153 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
154 	int count = sizeof(rset_cmd);
155 
156 	nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
157 
158 	/* Disable fw download */
159 	gpio_set_value(phy->gpio_fw, 0);
160 
161 	for (polarity = 0; polarity < 2; polarity++) {
162 		phy->en_polarity = polarity;
163 		retry = 3;
164 		while (retry--) {
165 			/* power off */
166 			gpio_set_value(phy->gpio_en, !phy->en_polarity);
167 			usleep_range(10000, 15000);
168 
169 			/* power on */
170 			gpio_set_value(phy->gpio_en, phy->en_polarity);
171 			usleep_range(10000, 15000);
172 
173 			/* send reset */
174 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
175 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
176 			if (ret == count) {
177 				nfc_info(&phy->i2c_dev->dev,
178 					 "nfc_en polarity : active %s\n",
179 					 (polarity == 0 ? "low" : "high"));
180 				goto out;
181 			}
182 		}
183 	}
184 
185 	nfc_err(&phy->i2c_dev->dev,
186 		"Could not detect nfc_en polarity, fallback to active high\n");
187 
188 out:
189 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
190 }
191 
192 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
193 {
194 	gpio_set_value(phy->gpio_fw, run_mode == PN544_FW_MODE ? 1 : 0);
195 	gpio_set_value(phy->gpio_en, phy->en_polarity);
196 	usleep_range(10000, 15000);
197 
198 	phy->run_mode = run_mode;
199 }
200 
201 static int pn544_hci_i2c_enable(void *phy_id)
202 {
203 	struct pn544_i2c_phy *phy = phy_id;
204 
205 	pr_info("%s\n", __func__);
206 
207 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
208 
209 	phy->powered = 1;
210 
211 	return 0;
212 }
213 
214 static void pn544_hci_i2c_disable(void *phy_id)
215 {
216 	struct pn544_i2c_phy *phy = phy_id;
217 
218 	gpio_set_value(phy->gpio_fw, 0);
219 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
220 	usleep_range(10000, 15000);
221 
222 	gpio_set_value(phy->gpio_en, phy->en_polarity);
223 	usleep_range(10000, 15000);
224 
225 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
226 	usleep_range(10000, 15000);
227 
228 	phy->powered = 0;
229 }
230 
231 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
232 {
233 	u16 crc;
234 	int len;
235 
236 	len = skb->len + 2;
237 	*skb_push(skb, 1) = len;
238 
239 	crc = crc_ccitt(0xffff, skb->data, skb->len);
240 	crc = ~crc;
241 	*skb_put(skb, 1) = crc & 0xff;
242 	*skb_put(skb, 1) = crc >> 8;
243 }
244 
245 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
246 {
247 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
248 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
249 }
250 
251 /*
252  * Writing a frame must not return the number of written bytes.
253  * It must return either zero for success, or <0 for error.
254  * In addition, it must not alter the skb
255  */
256 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
257 {
258 	int r;
259 	struct pn544_i2c_phy *phy = phy_id;
260 	struct i2c_client *client = phy->i2c_dev;
261 
262 	if (phy->hard_fault != 0)
263 		return phy->hard_fault;
264 
265 	usleep_range(3000, 6000);
266 
267 	pn544_hci_i2c_add_len_crc(skb);
268 
269 	I2C_DUMP_SKB("i2c frame written", skb);
270 
271 	r = i2c_master_send(client, skb->data, skb->len);
272 
273 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
274 		usleep_range(6000, 10000);
275 		r = i2c_master_send(client, skb->data, skb->len);
276 	}
277 
278 	if (r >= 0) {
279 		if (r != skb->len)
280 			r = -EREMOTEIO;
281 		else
282 			r = 0;
283 	}
284 
285 	pn544_hci_i2c_remove_len_crc(skb);
286 
287 	return r;
288 }
289 
290 static int check_crc(u8 *buf, int buflen)
291 {
292 	int len;
293 	u16 crc;
294 
295 	len = buf[0] + 1;
296 	crc = crc_ccitt(0xffff, buf, len - 2);
297 	crc = ~crc;
298 
299 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
300 		pr_err("CRC error 0x%x != 0x%x 0x%x\n",
301 		       crc, buf[len - 1], buf[len - 2]);
302 		pr_info("%s: BAD CRC\n", __func__);
303 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
304 			       16, 2, buf, buflen, false);
305 		return -EPERM;
306 	}
307 	return 0;
308 }
309 
310 /*
311  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
312  * that i2c bus will be flushed and that next read will start on a new frame.
313  * returned skb contains only LLC header and payload.
314  * returns:
315  * -EREMOTEIO : i2c read error (fatal)
316  * -EBADMSG : frame was incorrect and discarded
317  * -ENOMEM : cannot allocate skb, frame dropped
318  */
319 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
320 {
321 	int r;
322 	u8 len;
323 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
324 	struct i2c_client *client = phy->i2c_dev;
325 
326 	r = i2c_master_recv(client, &len, 1);
327 	if (r != 1) {
328 		nfc_err(&client->dev, "cannot read len byte\n");
329 		return -EREMOTEIO;
330 	}
331 
332 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
333 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
334 		nfc_err(&client->dev, "invalid len byte\n");
335 		r = -EBADMSG;
336 		goto flush;
337 	}
338 
339 	*skb = alloc_skb(1 + len, GFP_KERNEL);
340 	if (*skb == NULL) {
341 		r = -ENOMEM;
342 		goto flush;
343 	}
344 
345 	*skb_put(*skb, 1) = len;
346 
347 	r = i2c_master_recv(client, skb_put(*skb, len), len);
348 	if (r != len) {
349 		kfree_skb(*skb);
350 		return -EREMOTEIO;
351 	}
352 
353 	I2C_DUMP_SKB("i2c frame read", *skb);
354 
355 	r = check_crc((*skb)->data, (*skb)->len);
356 	if (r != 0) {
357 		kfree_skb(*skb);
358 		r = -EBADMSG;
359 		goto flush;
360 	}
361 
362 	skb_pull(*skb, 1);
363 	skb_trim(*skb, (*skb)->len - 2);
364 
365 	usleep_range(3000, 6000);
366 
367 	return 0;
368 
369 flush:
370 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
371 		r = -EREMOTEIO;
372 
373 	usleep_range(3000, 6000);
374 
375 	return r;
376 }
377 
378 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
379 {
380 	int r;
381 	struct pn544_i2c_fw_frame_response response;
382 	struct i2c_client *client = phy->i2c_dev;
383 
384 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
385 	if (r != sizeof(response)) {
386 		nfc_err(&client->dev, "cannot read fw status\n");
387 		return -EIO;
388 	}
389 
390 	usleep_range(3000, 6000);
391 
392 	switch (response.status) {
393 	case 0:
394 		return 0;
395 	case PN544_FW_CMD_RESULT_TIMEOUT:
396 		return -ETIMEDOUT;
397 	case PN544_FW_CMD_RESULT_BAD_CRC:
398 		return -ENODATA;
399 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
400 		return -EACCES;
401 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
402 		return -EPROTO;
403 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
404 		return -EINVAL;
405 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
406 		return -EBADMSG;
407 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
408 		return -EIO;
409 	default:
410 		return -EIO;
411 	}
412 }
413 
414 /*
415  * Reads an shdlc frame from the chip. This is not as straightforward as it
416  * seems. There are cases where we could loose the frame start synchronization.
417  * The frame format is len-data-crc, and corruption can occur anywhere while
418  * transiting on i2c bus, such that we could read an invalid len.
419  * In order to recover synchronization with the next frame, we must be sure
420  * to read the real amount of data without using the len byte. We do this by
421  * assuming the following:
422  * - the chip will always present only one single complete frame on the bus
423  *   before triggering the interrupt
424  * - the chip will not present a new frame until we have completely read
425  *   the previous one (or until we have handled the interrupt).
426  * The tricky case is when we read a corrupted len that is less than the real
427  * len. We must detect this here in order to determine that we need to flush
428  * the bus. This is the reason why we check the crc here.
429  */
430 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
431 {
432 	struct pn544_i2c_phy *phy = phy_id;
433 	struct i2c_client *client;
434 	struct sk_buff *skb = NULL;
435 	int r;
436 
437 	if (!phy || irq != phy->i2c_dev->irq) {
438 		WARN_ON_ONCE(1);
439 		return IRQ_NONE;
440 	}
441 
442 	client = phy->i2c_dev;
443 	dev_dbg(&client->dev, "IRQ\n");
444 
445 	if (phy->hard_fault != 0)
446 		return IRQ_HANDLED;
447 
448 	if (phy->run_mode == PN544_FW_MODE) {
449 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
450 		schedule_work(&phy->fw_work);
451 	} else {
452 		r = pn544_hci_i2c_read(phy, &skb);
453 		if (r == -EREMOTEIO) {
454 			phy->hard_fault = r;
455 
456 			nfc_hci_recv_frame(phy->hdev, NULL);
457 
458 			return IRQ_HANDLED;
459 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
460 			return IRQ_HANDLED;
461 		}
462 
463 		nfc_hci_recv_frame(phy->hdev, skb);
464 	}
465 	return IRQ_HANDLED;
466 }
467 
468 static struct nfc_phy_ops i2c_phy_ops = {
469 	.write = pn544_hci_i2c_write,
470 	.enable = pn544_hci_i2c_enable,
471 	.disable = pn544_hci_i2c_disable,
472 };
473 
474 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name)
475 {
476 	struct pn544_i2c_phy *phy = phy_id;
477 
478 	pr_info("Starting Firmware Download (%s)\n", firmware_name);
479 
480 	strcpy(phy->firmware_name, firmware_name);
481 
482 	phy->fw_work_state = FW_WORK_STATE_START;
483 
484 	schedule_work(&phy->fw_work);
485 
486 	return 0;
487 }
488 
489 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
490 					   int result)
491 {
492 	pr_info("Firmware Download Complete, result=%d\n", result);
493 
494 	pn544_hci_i2c_disable(phy);
495 
496 	phy->fw_work_state = FW_WORK_STATE_IDLE;
497 
498 	if (phy->fw) {
499 		release_firmware(phy->fw);
500 		phy->fw = NULL;
501 	}
502 
503 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
504 }
505 
506 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
507 				      const u8 *data, u16 datalen)
508 {
509 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
510 	struct pn544_i2c_fw_frame_write *framep;
511 	u16 params_len;
512 	int framelen;
513 	int r;
514 
515 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
516 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
517 
518 	framep = (struct pn544_i2c_fw_frame_write *) frame;
519 
520 	params_len = sizeof(framep->be_dest_addr) +
521 		     sizeof(framep->be_datalen) + datalen;
522 	framelen = params_len + sizeof(framep->cmd) +
523 			     sizeof(framep->be_length);
524 
525 	framep->cmd = PN544_FW_CMD_WRITE;
526 
527 	put_unaligned_be16(params_len, &framep->be_length);
528 
529 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
530 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
531 	framep->be_dest_addr[2] = dest_addr & 0xff;
532 
533 	put_unaligned_be16(datalen, &framep->be_datalen);
534 
535 	memcpy(framep->data, data, datalen);
536 
537 	r = i2c_master_send(client, frame, framelen);
538 
539 	if (r == framelen)
540 		return datalen;
541 	else if (r < 0)
542 		return r;
543 	else
544 		return -EIO;
545 }
546 
547 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
548 				      const u8 *data, u16 datalen)
549 {
550 	struct pn544_i2c_fw_frame_check frame;
551 	int r;
552 	u16 crc;
553 
554 	/* calculate local crc for the data we want to check */
555 	crc = crc_ccitt(0xffff, data, datalen);
556 
557 	frame.cmd = PN544_FW_CMD_CHECK;
558 
559 	put_unaligned_be16(sizeof(frame.be_start_addr) +
560 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
561 			   &frame.be_length);
562 
563 	/* tell the chip the memory region to which our crc applies */
564 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
565 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
566 	frame.be_start_addr[2] = start_addr & 0xff;
567 
568 	put_unaligned_be16(datalen, &frame.be_datalen);
569 
570 	/*
571 	 * and give our local crc. Chip will calculate its own crc for the
572 	 * region and compare with ours.
573 	 */
574 	put_unaligned_be16(crc, &frame.be_crc);
575 
576 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
577 
578 	if (r == sizeof(frame))
579 		return 0;
580 	else if (r < 0)
581 		return r;
582 	else
583 		return -EIO;
584 }
585 
586 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
587 {
588 	int r;
589 
590 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
591 				       phy->fw_blob_dest_addr + phy->fw_written,
592 				       phy->fw_blob_data + phy->fw_written,
593 				       phy->fw_blob_size - phy->fw_written);
594 	if (r < 0)
595 		return r;
596 
597 	phy->fw_written += r;
598 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
599 
600 	return 0;
601 }
602 
603 static void pn544_hci_i2c_fw_work(struct work_struct *work)
604 {
605 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
606 						fw_work);
607 	int r;
608 	struct pn544_i2c_fw_blob *blob;
609 
610 	switch (phy->fw_work_state) {
611 	case FW_WORK_STATE_START:
612 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
613 
614 		r = request_firmware(&phy->fw, phy->firmware_name,
615 				     &phy->i2c_dev->dev);
616 		if (r < 0)
617 			goto exit_state_start;
618 
619 		blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
620 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
621 		phy->fw_blob_dest_addr = get_unaligned_be32(&blob->be_destaddr);
622 		phy->fw_blob_data = blob->data;
623 
624 		phy->fw_written = 0;
625 		r = pn544_hci_i2c_fw_write_chunk(phy);
626 
627 exit_state_start:
628 		if (r < 0)
629 			pn544_hci_i2c_fw_work_complete(phy, r);
630 		break;
631 
632 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
633 		r = phy->fw_cmd_result;
634 		if (r < 0)
635 			goto exit_state_wait_write_answer;
636 
637 		if (phy->fw_written == phy->fw_blob_size) {
638 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
639 						       phy->fw_blob_dest_addr,
640 						       phy->fw_blob_data,
641 						       phy->fw_blob_size);
642 			if (r < 0)
643 				goto exit_state_wait_write_answer;
644 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
645 			break;
646 		}
647 
648 		r = pn544_hci_i2c_fw_write_chunk(phy);
649 
650 exit_state_wait_write_answer:
651 		if (r < 0)
652 			pn544_hci_i2c_fw_work_complete(phy, r);
653 		break;
654 
655 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
656 		r = phy->fw_cmd_result;
657 		if (r < 0)
658 			goto exit_state_wait_check_answer;
659 
660 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
661 		       phy->fw_blob_size);
662 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
663 		if (phy->fw_blob_size != 0) {
664 			phy->fw_blob_dest_addr =
665 					get_unaligned_be32(&blob->be_destaddr);
666 			phy->fw_blob_data = blob->data;
667 
668 			phy->fw_written = 0;
669 			r = pn544_hci_i2c_fw_write_chunk(phy);
670 		}
671 
672 exit_state_wait_check_answer:
673 		if (r < 0 || phy->fw_blob_size == 0)
674 			pn544_hci_i2c_fw_work_complete(phy, r);
675 		break;
676 
677 	default:
678 		break;
679 	}
680 }
681 
682 static int pn544_hci_i2c_probe(struct i2c_client *client,
683 			       const struct i2c_device_id *id)
684 {
685 	struct pn544_i2c_phy *phy;
686 	struct pn544_nfc_platform_data *pdata;
687 	int r = 0;
688 
689 	dev_dbg(&client->dev, "%s\n", __func__);
690 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
691 
692 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
693 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
694 		return -ENODEV;
695 	}
696 
697 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
698 			   GFP_KERNEL);
699 	if (!phy) {
700 		nfc_err(&client->dev,
701 			"Cannot allocate memory for pn544 i2c phy.\n");
702 		return -ENOMEM;
703 	}
704 
705 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
706 	phy->fw_work_state = FW_WORK_STATE_IDLE;
707 
708 	phy->i2c_dev = client;
709 	i2c_set_clientdata(client, phy);
710 
711 	pdata = client->dev.platform_data;
712 	if (pdata == NULL) {
713 		nfc_err(&client->dev, "No platform data\n");
714 		return -EINVAL;
715 	}
716 
717 	if (pdata->request_resources == NULL) {
718 		nfc_err(&client->dev, "request_resources() missing\n");
719 		return -EINVAL;
720 	}
721 
722 	r = pdata->request_resources(client);
723 	if (r) {
724 		nfc_err(&client->dev, "Cannot get platform resources\n");
725 		return r;
726 	}
727 
728 	phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
729 	phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
730 	phy->gpio_irq = pdata->get_gpio(NFC_GPIO_IRQ);
731 
732 	pn544_hci_i2c_platform_init(phy);
733 
734 	r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
735 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
736 				 PN544_HCI_I2C_DRIVER_NAME, phy);
737 	if (r < 0) {
738 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
739 		goto err_rti;
740 	}
741 
742 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
743 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
744 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
745 			    pn544_hci_i2c_fw_download, &phy->hdev);
746 	if (r < 0)
747 		goto err_hci;
748 
749 	return 0;
750 
751 err_hci:
752 	free_irq(client->irq, phy);
753 
754 err_rti:
755 	if (pdata->free_resources != NULL)
756 		pdata->free_resources();
757 
758 	return r;
759 }
760 
761 static int pn544_hci_i2c_remove(struct i2c_client *client)
762 {
763 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
764 	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
765 
766 	dev_dbg(&client->dev, "%s\n", __func__);
767 
768 	cancel_work_sync(&phy->fw_work);
769 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
770 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
771 
772 	pn544_hci_remove(phy->hdev);
773 
774 	if (phy->powered)
775 		pn544_hci_i2c_disable(phy);
776 
777 	free_irq(client->irq, phy);
778 	if (pdata->free_resources)
779 		pdata->free_resources();
780 
781 	return 0;
782 }
783 
784 static struct i2c_driver pn544_hci_i2c_driver = {
785 	.driver = {
786 		   .name = PN544_HCI_I2C_DRIVER_NAME,
787 		  },
788 	.probe = pn544_hci_i2c_probe,
789 	.id_table = pn544_hci_i2c_id_table,
790 	.remove = pn544_hci_i2c_remove,
791 };
792 
793 module_i2c_driver(pn544_hci_i2c_driver);
794 
795 MODULE_LICENSE("GPL");
796 MODULE_DESCRIPTION(DRIVER_DESC);
797