xref: /openbmc/linux/drivers/nfc/pn544/i2c.c (revision f7777dcc)
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 #include <linux/crc-ccitt.h>
22 #include <linux/module.h>
23 #include <linux/i2c.h>
24 #include <linux/gpio.h>
25 #include <linux/miscdevice.h>
26 #include <linux/interrupt.h>
27 #include <linux/delay.h>
28 #include <linux/nfc.h>
29 #include <linux/firmware.h>
30 #include <linux/unaligned/access_ok.h>
31 #include <linux/platform_data/pn544.h>
32 
33 #include <net/nfc/hci.h>
34 #include <net/nfc/llc.h>
35 #include <net/nfc/nfc.h>
36 
37 #include "pn544.h"
38 
39 #define PN544_I2C_FRAME_HEADROOM 1
40 #define PN544_I2C_FRAME_TAILROOM 2
41 
42 /* framing in HCI mode */
43 #define PN544_HCI_I2C_LLC_LEN		1
44 #define PN544_HCI_I2C_LLC_CRC		2
45 #define PN544_HCI_I2C_LLC_LEN_CRC	(PN544_HCI_I2C_LLC_LEN + \
46 					 PN544_HCI_I2C_LLC_CRC)
47 #define PN544_HCI_I2C_LLC_MIN_SIZE	(1 + PN544_HCI_I2C_LLC_LEN_CRC)
48 #define PN544_HCI_I2C_LLC_MAX_PAYLOAD	29
49 #define PN544_HCI_I2C_LLC_MAX_SIZE	(PN544_HCI_I2C_LLC_LEN_CRC + 1 + \
50 					 PN544_HCI_I2C_LLC_MAX_PAYLOAD)
51 
52 static struct i2c_device_id pn544_hci_i2c_id_table[] = {
53 	{"pn544", 0},
54 	{}
55 };
56 
57 MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);
58 
59 #define PN544_HCI_I2C_DRIVER_NAME "pn544_hci_i2c"
60 
61 #define PN544_FW_CMD_WRITE 0x08
62 #define PN544_FW_CMD_CHECK 0x06
63 
64 struct pn544_i2c_fw_frame_write {
65 	u8 cmd;
66 	u16 be_length;
67 	u8 be_dest_addr[3];
68 	u16 be_datalen;
69 	u8 data[];
70 } __packed;
71 
72 struct pn544_i2c_fw_frame_check {
73 	u8 cmd;
74 	u16 be_length;
75 	u8 be_start_addr[3];
76 	u16 be_datalen;
77 	u16 be_crc;
78 } __packed;
79 
80 struct pn544_i2c_fw_frame_response {
81 	u8 status;
82 	u16 be_length;
83 } __packed;
84 
85 struct pn544_i2c_fw_blob {
86 	u32 be_size;
87 	u32 be_destaddr;
88 	u8 data[];
89 };
90 
91 #define PN544_FW_CMD_RESULT_TIMEOUT 0x01
92 #define PN544_FW_CMD_RESULT_BAD_CRC 0x02
93 #define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
94 #define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
95 #define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
96 #define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
97 #define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
98 
99 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
100 
101 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
102 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
103 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
104 #define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
105 					 PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
106 					 PN544_FW_WRITE_BUFFER_MAX_LEN)
107 
108 #define FW_WORK_STATE_IDLE 1
109 #define FW_WORK_STATE_START 2
110 #define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
111 #define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
112 
113 struct pn544_i2c_phy {
114 	struct i2c_client *i2c_dev;
115 	struct nfc_hci_dev *hdev;
116 
117 	unsigned int gpio_en;
118 	unsigned int gpio_irq;
119 	unsigned int gpio_fw;
120 	unsigned int en_polarity;
121 
122 	struct work_struct fw_work;
123 	int fw_work_state;
124 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
125 	const struct firmware *fw;
126 	u32 fw_blob_dest_addr;
127 	size_t fw_blob_size;
128 	const u8 *fw_blob_data;
129 	size_t fw_written;
130 	int fw_cmd_result;
131 
132 	int powered;
133 	int run_mode;
134 
135 	int hard_fault;		/*
136 				 * < 0 if hardware error occured (e.g. i2c err)
137 				 * and prevents normal operation.
138 				 */
139 };
140 
141 #define I2C_DUMP_SKB(info, skb)					\
142 do {								\
143 	pr_debug("%s:\n", info);				\
144 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
145 		       16, 1, (skb)->data, (skb)->len, 0);	\
146 } while (0)
147 
148 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
149 {
150 	int polarity, retry, ret;
151 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
152 	int count = sizeof(rset_cmd);
153 
154 	pr_info(DRIVER_DESC ": %s\n", __func__);
155 	dev_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
156 
157 	/* Disable fw download */
158 	gpio_set_value(phy->gpio_fw, 0);
159 
160 	for (polarity = 0; polarity < 2; polarity++) {
161 		phy->en_polarity = polarity;
162 		retry = 3;
163 		while (retry--) {
164 			/* power off */
165 			gpio_set_value(phy->gpio_en, !phy->en_polarity);
166 			usleep_range(10000, 15000);
167 
168 			/* power on */
169 			gpio_set_value(phy->gpio_en, phy->en_polarity);
170 			usleep_range(10000, 15000);
171 
172 			/* send reset */
173 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
174 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
175 			if (ret == count) {
176 				dev_info(&phy->i2c_dev->dev,
177 					 "nfc_en polarity : active %s\n",
178 					 (polarity == 0 ? "low" : "high"));
179 				goto out;
180 			}
181 		}
182 	}
183 
184 	dev_err(&phy->i2c_dev->dev,
185 		"Could not detect nfc_en polarity, fallback to active high\n");
186 
187 out:
188 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
189 }
190 
191 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
192 {
193 	gpio_set_value(phy->gpio_fw, run_mode == PN544_FW_MODE ? 1 : 0);
194 	gpio_set_value(phy->gpio_en, phy->en_polarity);
195 	usleep_range(10000, 15000);
196 
197 	phy->run_mode = run_mode;
198 }
199 
200 static int pn544_hci_i2c_enable(void *phy_id)
201 {
202 	struct pn544_i2c_phy *phy = phy_id;
203 
204 	pr_info(DRIVER_DESC ": %s\n", __func__);
205 
206 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
207 
208 	phy->powered = 1;
209 
210 	return 0;
211 }
212 
213 static void pn544_hci_i2c_disable(void *phy_id)
214 {
215 	struct pn544_i2c_phy *phy = phy_id;
216 
217 	pr_info(DRIVER_DESC ": %s\n", __func__);
218 
219 	gpio_set_value(phy->gpio_fw, 0);
220 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
221 	usleep_range(10000, 15000);
222 
223 	gpio_set_value(phy->gpio_en, phy->en_polarity);
224 	usleep_range(10000, 15000);
225 
226 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
227 	usleep_range(10000, 15000);
228 
229 	phy->powered = 0;
230 }
231 
232 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
233 {
234 	u16 crc;
235 	int len;
236 
237 	len = skb->len + 2;
238 	*skb_push(skb, 1) = len;
239 
240 	crc = crc_ccitt(0xffff, skb->data, skb->len);
241 	crc = ~crc;
242 	*skb_put(skb, 1) = crc & 0xff;
243 	*skb_put(skb, 1) = crc >> 8;
244 }
245 
246 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
247 {
248 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
249 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
250 }
251 
252 /*
253  * Writing a frame must not return the number of written bytes.
254  * It must return either zero for success, or <0 for error.
255  * In addition, it must not alter the skb
256  */
257 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
258 {
259 	int r;
260 	struct pn544_i2c_phy *phy = phy_id;
261 	struct i2c_client *client = phy->i2c_dev;
262 
263 	if (phy->hard_fault != 0)
264 		return phy->hard_fault;
265 
266 	usleep_range(3000, 6000);
267 
268 	pn544_hci_i2c_add_len_crc(skb);
269 
270 	I2C_DUMP_SKB("i2c frame written", skb);
271 
272 	r = i2c_master_send(client, skb->data, skb->len);
273 
274 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
275 		usleep_range(6000, 10000);
276 		r = i2c_master_send(client, skb->data, skb->len);
277 	}
278 
279 	if (r >= 0) {
280 		if (r != skb->len)
281 			r = -EREMOTEIO;
282 		else
283 			r = 0;
284 	}
285 
286 	pn544_hci_i2c_remove_len_crc(skb);
287 
288 	return r;
289 }
290 
291 static int check_crc(u8 *buf, int buflen)
292 {
293 	int len;
294 	u16 crc;
295 
296 	len = buf[0] + 1;
297 	crc = crc_ccitt(0xffff, buf, len - 2);
298 	crc = ~crc;
299 
300 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
301 		pr_err(PN544_HCI_I2C_DRIVER_NAME
302 		       ": CRC error 0x%x != 0x%x 0x%x\n",
303 		       crc, buf[len - 1], buf[len - 2]);
304 
305 		pr_info(DRIVER_DESC ": %s : BAD CRC\n", __func__);
306 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
307 			       16, 2, buf, buflen, false);
308 		return -EPERM;
309 	}
310 	return 0;
311 }
312 
313 /*
314  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
315  * that i2c bus will be flushed and that next read will start on a new frame.
316  * returned skb contains only LLC header and payload.
317  * returns:
318  * -EREMOTEIO : i2c read error (fatal)
319  * -EBADMSG : frame was incorrect and discarded
320  * -ENOMEM : cannot allocate skb, frame dropped
321  */
322 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
323 {
324 	int r;
325 	u8 len;
326 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
327 	struct i2c_client *client = phy->i2c_dev;
328 
329 	r = i2c_master_recv(client, &len, 1);
330 	if (r != 1) {
331 		dev_err(&client->dev, "cannot read len byte\n");
332 		return -EREMOTEIO;
333 	}
334 
335 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
336 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
337 		dev_err(&client->dev, "invalid len byte\n");
338 		r = -EBADMSG;
339 		goto flush;
340 	}
341 
342 	*skb = alloc_skb(1 + len, GFP_KERNEL);
343 	if (*skb == NULL) {
344 		r = -ENOMEM;
345 		goto flush;
346 	}
347 
348 	*skb_put(*skb, 1) = len;
349 
350 	r = i2c_master_recv(client, skb_put(*skb, len), len);
351 	if (r != len) {
352 		kfree_skb(*skb);
353 		return -EREMOTEIO;
354 	}
355 
356 	I2C_DUMP_SKB("i2c frame read", *skb);
357 
358 	r = check_crc((*skb)->data, (*skb)->len);
359 	if (r != 0) {
360 		kfree_skb(*skb);
361 		r = -EBADMSG;
362 		goto flush;
363 	}
364 
365 	skb_pull(*skb, 1);
366 	skb_trim(*skb, (*skb)->len - 2);
367 
368 	usleep_range(3000, 6000);
369 
370 	return 0;
371 
372 flush:
373 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
374 		r = -EREMOTEIO;
375 
376 	usleep_range(3000, 6000);
377 
378 	return r;
379 }
380 
381 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
382 {
383 	int r;
384 	struct pn544_i2c_fw_frame_response response;
385 	struct i2c_client *client = phy->i2c_dev;
386 
387 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
388 	if (r != sizeof(response)) {
389 		dev_err(&client->dev, "cannot read fw status\n");
390 		return -EIO;
391 	}
392 
393 	usleep_range(3000, 6000);
394 
395 	switch (response.status) {
396 	case 0:
397 		return 0;
398 	case PN544_FW_CMD_RESULT_TIMEOUT:
399 		return -ETIMEDOUT;
400 	case PN544_FW_CMD_RESULT_BAD_CRC:
401 		return -ENODATA;
402 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
403 		return -EACCES;
404 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
405 		return -EPROTO;
406 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
407 		return -EINVAL;
408 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
409 		return -EBADMSG;
410 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
411 		return -EIO;
412 	default:
413 		return -EIO;
414 	}
415 }
416 
417 /*
418  * Reads an shdlc frame from the chip. This is not as straightforward as it
419  * seems. There are cases where we could loose the frame start synchronization.
420  * The frame format is len-data-crc, and corruption can occur anywhere while
421  * transiting on i2c bus, such that we could read an invalid len.
422  * In order to recover synchronization with the next frame, we must be sure
423  * to read the real amount of data without using the len byte. We do this by
424  * assuming the following:
425  * - the chip will always present only one single complete frame on the bus
426  *   before triggering the interrupt
427  * - the chip will not present a new frame until we have completely read
428  *   the previous one (or until we have handled the interrupt).
429  * The tricky case is when we read a corrupted len that is less than the real
430  * len. We must detect this here in order to determine that we need to flush
431  * the bus. This is the reason why we check the crc here.
432  */
433 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
434 {
435 	struct pn544_i2c_phy *phy = phy_id;
436 	struct i2c_client *client;
437 	struct sk_buff *skb = NULL;
438 	int r;
439 
440 	if (!phy || irq != phy->i2c_dev->irq) {
441 		WARN_ON_ONCE(1);
442 		return IRQ_NONE;
443 	}
444 
445 	client = phy->i2c_dev;
446 	dev_dbg(&client->dev, "IRQ\n");
447 
448 	if (phy->hard_fault != 0)
449 		return IRQ_HANDLED;
450 
451 	if (phy->run_mode == PN544_FW_MODE) {
452 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
453 		schedule_work(&phy->fw_work);
454 	} else {
455 		r = pn544_hci_i2c_read(phy, &skb);
456 		if (r == -EREMOTEIO) {
457 			phy->hard_fault = r;
458 
459 			nfc_hci_recv_frame(phy->hdev, NULL);
460 
461 			return IRQ_HANDLED;
462 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
463 			return IRQ_HANDLED;
464 		}
465 
466 		nfc_hci_recv_frame(phy->hdev, skb);
467 	}
468 	return IRQ_HANDLED;
469 }
470 
471 static struct nfc_phy_ops i2c_phy_ops = {
472 	.write = pn544_hci_i2c_write,
473 	.enable = pn544_hci_i2c_enable,
474 	.disable = pn544_hci_i2c_disable,
475 };
476 
477 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name)
478 {
479 	struct pn544_i2c_phy *phy = phy_id;
480 
481 	pr_info(DRIVER_DESC ": Starting Firmware Download (%s)\n",
482 		firmware_name);
483 
484 	strcpy(phy->firmware_name, firmware_name);
485 
486 	phy->fw_work_state = FW_WORK_STATE_START;
487 
488 	schedule_work(&phy->fw_work);
489 
490 	return 0;
491 }
492 
493 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
494 					   int result)
495 {
496 	pr_info(DRIVER_DESC ": Firmware Download Complete, result=%d\n", result);
497 
498 	pn544_hci_i2c_disable(phy);
499 
500 	phy->fw_work_state = FW_WORK_STATE_IDLE;
501 
502 	if (phy->fw) {
503 		release_firmware(phy->fw);
504 		phy->fw = NULL;
505 	}
506 
507 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
508 }
509 
510 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
511 				      const u8 *data, u16 datalen)
512 {
513 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
514 	struct pn544_i2c_fw_frame_write *framep;
515 	u16 params_len;
516 	int framelen;
517 	int r;
518 
519 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
520 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
521 
522 	framep = (struct pn544_i2c_fw_frame_write *) frame;
523 
524 	params_len = sizeof(framep->be_dest_addr) +
525 		     sizeof(framep->be_datalen) + datalen;
526 	framelen = params_len + sizeof(framep->cmd) +
527 			     sizeof(framep->be_length);
528 
529 	framep->cmd = PN544_FW_CMD_WRITE;
530 
531 	put_unaligned_be16(params_len, &framep->be_length);
532 
533 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
534 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
535 	framep->be_dest_addr[2] = dest_addr & 0xff;
536 
537 	put_unaligned_be16(datalen, &framep->be_datalen);
538 
539 	memcpy(framep->data, data, datalen);
540 
541 	r = i2c_master_send(client, frame, framelen);
542 
543 	if (r == framelen)
544 		return datalen;
545 	else if (r < 0)
546 		return r;
547 	else
548 		return -EIO;
549 }
550 
551 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
552 				      const u8 *data, u16 datalen)
553 {
554 	struct pn544_i2c_fw_frame_check frame;
555 	int r;
556 	u16 crc;
557 
558 	/* calculate local crc for the data we want to check */
559 	crc = crc_ccitt(0xffff, data, datalen);
560 
561 	frame.cmd = PN544_FW_CMD_CHECK;
562 
563 	put_unaligned_be16(sizeof(frame.be_start_addr) +
564 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
565 			   &frame.be_length);
566 
567 	/* tell the chip the memory region to which our crc applies */
568 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
569 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
570 	frame.be_start_addr[2] = start_addr & 0xff;
571 
572 	put_unaligned_be16(datalen, &frame.be_datalen);
573 
574 	/*
575 	 * and give our local crc. Chip will calculate its own crc for the
576 	 * region and compare with ours.
577 	 */
578 	put_unaligned_be16(crc, &frame.be_crc);
579 
580 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
581 
582 	if (r == sizeof(frame))
583 		return 0;
584 	else if (r < 0)
585 		return r;
586 	else
587 		return -EIO;
588 }
589 
590 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
591 {
592 	int r;
593 
594 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
595 				       phy->fw_blob_dest_addr + phy->fw_written,
596 				       phy->fw_blob_data + phy->fw_written,
597 				       phy->fw_blob_size - phy->fw_written);
598 	if (r < 0)
599 		return r;
600 
601 	phy->fw_written += r;
602 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
603 
604 	return 0;
605 }
606 
607 static void pn544_hci_i2c_fw_work(struct work_struct *work)
608 {
609 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
610 						fw_work);
611 	int r;
612 	struct pn544_i2c_fw_blob *blob;
613 
614 	switch (phy->fw_work_state) {
615 	case FW_WORK_STATE_START:
616 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
617 
618 		r = request_firmware(&phy->fw, phy->firmware_name,
619 				     &phy->i2c_dev->dev);
620 		if (r < 0)
621 			goto exit_state_start;
622 
623 		blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
624 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
625 		phy->fw_blob_dest_addr = get_unaligned_be32(&blob->be_destaddr);
626 		phy->fw_blob_data = blob->data;
627 
628 		phy->fw_written = 0;
629 		r = pn544_hci_i2c_fw_write_chunk(phy);
630 
631 exit_state_start:
632 		if (r < 0)
633 			pn544_hci_i2c_fw_work_complete(phy, r);
634 		break;
635 
636 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
637 		r = phy->fw_cmd_result;
638 		if (r < 0)
639 			goto exit_state_wait_write_answer;
640 
641 		if (phy->fw_written == phy->fw_blob_size) {
642 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
643 						       phy->fw_blob_dest_addr,
644 						       phy->fw_blob_data,
645 						       phy->fw_blob_size);
646 			if (r < 0)
647 				goto exit_state_wait_write_answer;
648 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
649 			break;
650 		}
651 
652 		r = pn544_hci_i2c_fw_write_chunk(phy);
653 
654 exit_state_wait_write_answer:
655 		if (r < 0)
656 			pn544_hci_i2c_fw_work_complete(phy, r);
657 		break;
658 
659 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
660 		r = phy->fw_cmd_result;
661 		if (r < 0)
662 			goto exit_state_wait_check_answer;
663 
664 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
665 		       phy->fw_blob_size);
666 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
667 		if (phy->fw_blob_size != 0) {
668 			phy->fw_blob_dest_addr =
669 					get_unaligned_be32(&blob->be_destaddr);
670 			phy->fw_blob_data = blob->data;
671 
672 			phy->fw_written = 0;
673 			r = pn544_hci_i2c_fw_write_chunk(phy);
674 		}
675 
676 exit_state_wait_check_answer:
677 		if (r < 0 || phy->fw_blob_size == 0)
678 			pn544_hci_i2c_fw_work_complete(phy, r);
679 		break;
680 
681 	default:
682 		break;
683 	}
684 }
685 
686 static int pn544_hci_i2c_probe(struct i2c_client *client,
687 			       const struct i2c_device_id *id)
688 {
689 	struct pn544_i2c_phy *phy;
690 	struct pn544_nfc_platform_data *pdata;
691 	int r = 0;
692 
693 	dev_dbg(&client->dev, "%s\n", __func__);
694 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
695 
696 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
697 		dev_err(&client->dev, "Need I2C_FUNC_I2C\n");
698 		return -ENODEV;
699 	}
700 
701 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
702 			   GFP_KERNEL);
703 	if (!phy) {
704 		dev_err(&client->dev,
705 			"Cannot allocate memory for pn544 i2c phy.\n");
706 		return -ENOMEM;
707 	}
708 
709 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
710 	phy->fw_work_state = FW_WORK_STATE_IDLE;
711 
712 	phy->i2c_dev = client;
713 	i2c_set_clientdata(client, phy);
714 
715 	pdata = client->dev.platform_data;
716 	if (pdata == NULL) {
717 		dev_err(&client->dev, "No platform data\n");
718 		return -EINVAL;
719 	}
720 
721 	if (pdata->request_resources == NULL) {
722 		dev_err(&client->dev, "request_resources() missing\n");
723 		return -EINVAL;
724 	}
725 
726 	r = pdata->request_resources(client);
727 	if (r) {
728 		dev_err(&client->dev, "Cannot get platform resources\n");
729 		return r;
730 	}
731 
732 	phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
733 	phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
734 	phy->gpio_irq = pdata->get_gpio(NFC_GPIO_IRQ);
735 
736 	pn544_hci_i2c_platform_init(phy);
737 
738 	r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
739 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
740 				 PN544_HCI_I2C_DRIVER_NAME, phy);
741 	if (r < 0) {
742 		dev_err(&client->dev, "Unable to register IRQ handler\n");
743 		goto err_rti;
744 	}
745 
746 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
747 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
748 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
749 			    pn544_hci_i2c_fw_download, &phy->hdev);
750 	if (r < 0)
751 		goto err_hci;
752 
753 	return 0;
754 
755 err_hci:
756 	free_irq(client->irq, phy);
757 
758 err_rti:
759 	if (pdata->free_resources != NULL)
760 		pdata->free_resources();
761 
762 	return r;
763 }
764 
765 static int pn544_hci_i2c_remove(struct i2c_client *client)
766 {
767 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
768 	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
769 
770 	dev_dbg(&client->dev, "%s\n", __func__);
771 
772 	cancel_work_sync(&phy->fw_work);
773 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
774 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
775 
776 	pn544_hci_remove(phy->hdev);
777 
778 	if (phy->powered)
779 		pn544_hci_i2c_disable(phy);
780 
781 	free_irq(client->irq, phy);
782 	if (pdata->free_resources)
783 		pdata->free_resources();
784 
785 	return 0;
786 }
787 
788 static struct i2c_driver pn544_hci_i2c_driver = {
789 	.driver = {
790 		   .name = PN544_HCI_I2C_DRIVER_NAME,
791 		  },
792 	.probe = pn544_hci_i2c_probe,
793 	.id_table = pn544_hci_i2c_id_table,
794 	.remove = pn544_hci_i2c_remove,
795 };
796 
797 module_i2c_driver(pn544_hci_i2c_driver);
798 
799 MODULE_LICENSE("GPL");
800 MODULE_DESCRIPTION(DRIVER_DESC);
801