xref: /openbmc/linux/drivers/nfc/pn544/i2c.c (revision 275876e2)
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, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/of_gpio.h>
26 #include <linux/of_irq.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 /*
64  * Exposed through the 4 most significant bytes
65  * from the HCI SW_VERSION first byte, a.k.a.
66  * SW RomLib.
67  */
68 #define PN544_HW_VARIANT_C2 0xa
69 #define PN544_HW_VARIANT_C3 0xb
70 
71 #define PN544_FW_CMD_RESET 0x01
72 #define PN544_FW_CMD_WRITE 0x08
73 #define PN544_FW_CMD_CHECK 0x06
74 #define PN544_FW_CMD_SECURE_WRITE 0x0C
75 #define PN544_FW_CMD_SECURE_CHUNK_WRITE 0x0D
76 
77 struct pn544_i2c_fw_frame_write {
78 	u8 cmd;
79 	u16 be_length;
80 	u8 be_dest_addr[3];
81 	u16 be_datalen;
82 	u8 data[];
83 } __packed;
84 
85 struct pn544_i2c_fw_frame_check {
86 	u8 cmd;
87 	u16 be_length;
88 	u8 be_start_addr[3];
89 	u16 be_datalen;
90 	u16 be_crc;
91 } __packed;
92 
93 struct pn544_i2c_fw_frame_response {
94 	u8 status;
95 	u16 be_length;
96 } __packed;
97 
98 struct pn544_i2c_fw_blob {
99 	u32 be_size;
100 	u32 be_destaddr;
101 	u8 data[];
102 };
103 
104 struct pn544_i2c_fw_secure_frame {
105 	u8 cmd;
106 	u16 be_datalen;
107 	u8 data[];
108 } __packed;
109 
110 struct pn544_i2c_fw_secure_blob {
111 	u64 header;
112 	u8 data[];
113 };
114 
115 #define PN544_FW_CMD_RESULT_TIMEOUT 0x01
116 #define PN544_FW_CMD_RESULT_BAD_CRC 0x02
117 #define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
118 #define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
119 #define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
120 #define PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND 0x13
121 #define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
122 #define PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR 0x19
123 #define PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR 0x1D
124 #define PN544_FW_CMD_RESULT_MEMORY_ERROR 0x20
125 #define PN544_FW_CMD_RESULT_CHUNK_OK 0x21
126 #define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
127 #define PN544_FW_CMD_RESULT_COMMAND_REJECTED 0xE0
128 #define PN544_FW_CMD_RESULT_CHUNK_ERROR 0xE6
129 
130 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
131 
132 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
133 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
134 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
135 #define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
136 					 PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
137 					 PN544_FW_WRITE_BUFFER_MAX_LEN)
138 #define PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN 3
139 #define PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN (PN544_FW_I2C_MAX_PAYLOAD -\
140 			PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN)
141 #define PN544_FW_SECURE_FRAME_HEADER_LEN 3
142 #define PN544_FW_SECURE_BLOB_HEADER_LEN 8
143 
144 #define FW_WORK_STATE_IDLE 1
145 #define FW_WORK_STATE_START 2
146 #define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
147 #define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
148 #define FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER 5
149 
150 struct pn544_i2c_phy {
151 	struct i2c_client *i2c_dev;
152 	struct nfc_hci_dev *hdev;
153 
154 	unsigned int gpio_en;
155 	unsigned int gpio_irq;
156 	unsigned int gpio_fw;
157 	unsigned int en_polarity;
158 
159 	u8 hw_variant;
160 
161 	struct work_struct fw_work;
162 	int fw_work_state;
163 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
164 	const struct firmware *fw;
165 	u32 fw_blob_dest_addr;
166 	size_t fw_blob_size;
167 	const u8 *fw_blob_data;
168 	size_t fw_written;
169 	size_t fw_size;
170 
171 	int fw_cmd_result;
172 
173 	int powered;
174 	int run_mode;
175 
176 	int hard_fault;		/*
177 				 * < 0 if hardware error occured (e.g. i2c err)
178 				 * and prevents normal operation.
179 				 */
180 };
181 
182 #define I2C_DUMP_SKB(info, skb)					\
183 do {								\
184 	pr_debug("%s:\n", info);				\
185 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
186 		       16, 1, (skb)->data, (skb)->len, 0);	\
187 } while (0)
188 
189 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
190 {
191 	int polarity, retry, ret;
192 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
193 	int count = sizeof(rset_cmd);
194 
195 	nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
196 
197 	/* Disable fw download */
198 	gpio_set_value(phy->gpio_fw, 0);
199 
200 	for (polarity = 0; polarity < 2; polarity++) {
201 		phy->en_polarity = polarity;
202 		retry = 3;
203 		while (retry--) {
204 			/* power off */
205 			gpio_set_value(phy->gpio_en, !phy->en_polarity);
206 			usleep_range(10000, 15000);
207 
208 			/* power on */
209 			gpio_set_value(phy->gpio_en, phy->en_polarity);
210 			usleep_range(10000, 15000);
211 
212 			/* send reset */
213 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
214 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
215 			if (ret == count) {
216 				nfc_info(&phy->i2c_dev->dev,
217 					 "nfc_en polarity : active %s\n",
218 					 (polarity == 0 ? "low" : "high"));
219 				goto out;
220 			}
221 		}
222 	}
223 
224 	nfc_err(&phy->i2c_dev->dev,
225 		"Could not detect nfc_en polarity, fallback to active high\n");
226 
227 out:
228 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
229 }
230 
231 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
232 {
233 	gpio_set_value(phy->gpio_fw, run_mode == PN544_FW_MODE ? 1 : 0);
234 	gpio_set_value(phy->gpio_en, phy->en_polarity);
235 	usleep_range(10000, 15000);
236 
237 	phy->run_mode = run_mode;
238 }
239 
240 static int pn544_hci_i2c_enable(void *phy_id)
241 {
242 	struct pn544_i2c_phy *phy = phy_id;
243 
244 	pr_info("%s\n", __func__);
245 
246 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
247 
248 	phy->powered = 1;
249 
250 	return 0;
251 }
252 
253 static void pn544_hci_i2c_disable(void *phy_id)
254 {
255 	struct pn544_i2c_phy *phy = phy_id;
256 
257 	gpio_set_value(phy->gpio_fw, 0);
258 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
259 	usleep_range(10000, 15000);
260 
261 	gpio_set_value(phy->gpio_en, phy->en_polarity);
262 	usleep_range(10000, 15000);
263 
264 	gpio_set_value(phy->gpio_en, !phy->en_polarity);
265 	usleep_range(10000, 15000);
266 
267 	phy->powered = 0;
268 }
269 
270 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
271 {
272 	u16 crc;
273 	int len;
274 
275 	len = skb->len + 2;
276 	*skb_push(skb, 1) = len;
277 
278 	crc = crc_ccitt(0xffff, skb->data, skb->len);
279 	crc = ~crc;
280 	*skb_put(skb, 1) = crc & 0xff;
281 	*skb_put(skb, 1) = crc >> 8;
282 }
283 
284 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
285 {
286 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
287 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
288 }
289 
290 /*
291  * Writing a frame must not return the number of written bytes.
292  * It must return either zero for success, or <0 for error.
293  * In addition, it must not alter the skb
294  */
295 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
296 {
297 	int r;
298 	struct pn544_i2c_phy *phy = phy_id;
299 	struct i2c_client *client = phy->i2c_dev;
300 
301 	if (phy->hard_fault != 0)
302 		return phy->hard_fault;
303 
304 	usleep_range(3000, 6000);
305 
306 	pn544_hci_i2c_add_len_crc(skb);
307 
308 	I2C_DUMP_SKB("i2c frame written", skb);
309 
310 	r = i2c_master_send(client, skb->data, skb->len);
311 
312 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
313 		usleep_range(6000, 10000);
314 		r = i2c_master_send(client, skb->data, skb->len);
315 	}
316 
317 	if (r >= 0) {
318 		if (r != skb->len)
319 			r = -EREMOTEIO;
320 		else
321 			r = 0;
322 	}
323 
324 	pn544_hci_i2c_remove_len_crc(skb);
325 
326 	return r;
327 }
328 
329 static int check_crc(u8 *buf, int buflen)
330 {
331 	int len;
332 	u16 crc;
333 
334 	len = buf[0] + 1;
335 	crc = crc_ccitt(0xffff, buf, len - 2);
336 	crc = ~crc;
337 
338 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
339 		pr_err("CRC error 0x%x != 0x%x 0x%x\n",
340 		       crc, buf[len - 1], buf[len - 2]);
341 		pr_info("%s: BAD CRC\n", __func__);
342 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
343 			       16, 2, buf, buflen, false);
344 		return -EPERM;
345 	}
346 	return 0;
347 }
348 
349 /*
350  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
351  * that i2c bus will be flushed and that next read will start on a new frame.
352  * returned skb contains only LLC header and payload.
353  * returns:
354  * -EREMOTEIO : i2c read error (fatal)
355  * -EBADMSG : frame was incorrect and discarded
356  * -ENOMEM : cannot allocate skb, frame dropped
357  */
358 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
359 {
360 	int r;
361 	u8 len;
362 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
363 	struct i2c_client *client = phy->i2c_dev;
364 
365 	r = i2c_master_recv(client, &len, 1);
366 	if (r != 1) {
367 		nfc_err(&client->dev, "cannot read len byte\n");
368 		return -EREMOTEIO;
369 	}
370 
371 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
372 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
373 		nfc_err(&client->dev, "invalid len byte\n");
374 		r = -EBADMSG;
375 		goto flush;
376 	}
377 
378 	*skb = alloc_skb(1 + len, GFP_KERNEL);
379 	if (*skb == NULL) {
380 		r = -ENOMEM;
381 		goto flush;
382 	}
383 
384 	*skb_put(*skb, 1) = len;
385 
386 	r = i2c_master_recv(client, skb_put(*skb, len), len);
387 	if (r != len) {
388 		kfree_skb(*skb);
389 		return -EREMOTEIO;
390 	}
391 
392 	I2C_DUMP_SKB("i2c frame read", *skb);
393 
394 	r = check_crc((*skb)->data, (*skb)->len);
395 	if (r != 0) {
396 		kfree_skb(*skb);
397 		r = -EBADMSG;
398 		goto flush;
399 	}
400 
401 	skb_pull(*skb, 1);
402 	skb_trim(*skb, (*skb)->len - 2);
403 
404 	usleep_range(3000, 6000);
405 
406 	return 0;
407 
408 flush:
409 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
410 		r = -EREMOTEIO;
411 
412 	usleep_range(3000, 6000);
413 
414 	return r;
415 }
416 
417 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
418 {
419 	int r;
420 	struct pn544_i2c_fw_frame_response response;
421 	struct i2c_client *client = phy->i2c_dev;
422 
423 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
424 	if (r != sizeof(response)) {
425 		nfc_err(&client->dev, "cannot read fw status\n");
426 		return -EIO;
427 	}
428 
429 	usleep_range(3000, 6000);
430 
431 	switch (response.status) {
432 	case 0:
433 		return 0;
434 	case PN544_FW_CMD_RESULT_CHUNK_OK:
435 		return response.status;
436 	case PN544_FW_CMD_RESULT_TIMEOUT:
437 		return -ETIMEDOUT;
438 	case PN544_FW_CMD_RESULT_BAD_CRC:
439 		return -ENODATA;
440 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
441 		return -EACCES;
442 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
443 		return -EPROTO;
444 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
445 		return -EINVAL;
446 	case PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND:
447 		return -ENOTSUPP;
448 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
449 		return -EBADMSG;
450 	case PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR:
451 		return -ENOKEY;
452 	case PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR:
453 		return -EINVAL;
454 	case PN544_FW_CMD_RESULT_MEMORY_ERROR:
455 		return -ENOMEM;
456 	case PN544_FW_CMD_RESULT_COMMAND_REJECTED:
457 		return -EACCES;
458 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
459 	case PN544_FW_CMD_RESULT_CHUNK_ERROR:
460 		return -EIO;
461 	default:
462 		return -EIO;
463 	}
464 }
465 
466 /*
467  * Reads an shdlc frame from the chip. This is not as straightforward as it
468  * seems. There are cases where we could loose the frame start synchronization.
469  * The frame format is len-data-crc, and corruption can occur anywhere while
470  * transiting on i2c bus, such that we could read an invalid len.
471  * In order to recover synchronization with the next frame, we must be sure
472  * to read the real amount of data without using the len byte. We do this by
473  * assuming the following:
474  * - the chip will always present only one single complete frame on the bus
475  *   before triggering the interrupt
476  * - the chip will not present a new frame until we have completely read
477  *   the previous one (or until we have handled the interrupt).
478  * The tricky case is when we read a corrupted len that is less than the real
479  * len. We must detect this here in order to determine that we need to flush
480  * the bus. This is the reason why we check the crc here.
481  */
482 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
483 {
484 	struct pn544_i2c_phy *phy = phy_id;
485 	struct i2c_client *client;
486 	struct sk_buff *skb = NULL;
487 	int r;
488 
489 	if (!phy || irq != phy->i2c_dev->irq) {
490 		WARN_ON_ONCE(1);
491 		return IRQ_NONE;
492 	}
493 
494 	client = phy->i2c_dev;
495 	dev_dbg(&client->dev, "IRQ\n");
496 
497 	if (phy->hard_fault != 0)
498 		return IRQ_HANDLED;
499 
500 	if (phy->run_mode == PN544_FW_MODE) {
501 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
502 		schedule_work(&phy->fw_work);
503 	} else {
504 		r = pn544_hci_i2c_read(phy, &skb);
505 		if (r == -EREMOTEIO) {
506 			phy->hard_fault = r;
507 
508 			nfc_hci_recv_frame(phy->hdev, NULL);
509 
510 			return IRQ_HANDLED;
511 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
512 			return IRQ_HANDLED;
513 		}
514 
515 		nfc_hci_recv_frame(phy->hdev, skb);
516 	}
517 	return IRQ_HANDLED;
518 }
519 
520 static struct nfc_phy_ops i2c_phy_ops = {
521 	.write = pn544_hci_i2c_write,
522 	.enable = pn544_hci_i2c_enable,
523 	.disable = pn544_hci_i2c_disable,
524 };
525 
526 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name,
527 					u8 hw_variant)
528 {
529 	struct pn544_i2c_phy *phy = phy_id;
530 
531 	pr_info("Starting Firmware Download (%s)\n", firmware_name);
532 
533 	strcpy(phy->firmware_name, firmware_name);
534 
535 	phy->hw_variant = hw_variant;
536 	phy->fw_work_state = FW_WORK_STATE_START;
537 
538 	schedule_work(&phy->fw_work);
539 
540 	return 0;
541 }
542 
543 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
544 					   int result)
545 {
546 	pr_info("Firmware Download Complete, result=%d\n", result);
547 
548 	pn544_hci_i2c_disable(phy);
549 
550 	phy->fw_work_state = FW_WORK_STATE_IDLE;
551 
552 	if (phy->fw) {
553 		release_firmware(phy->fw);
554 		phy->fw = NULL;
555 	}
556 
557 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
558 }
559 
560 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
561 				      const u8 *data, u16 datalen)
562 {
563 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
564 	struct pn544_i2c_fw_frame_write *framep;
565 	u16 params_len;
566 	int framelen;
567 	int r;
568 
569 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
570 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
571 
572 	framep = (struct pn544_i2c_fw_frame_write *) frame;
573 
574 	params_len = sizeof(framep->be_dest_addr) +
575 		     sizeof(framep->be_datalen) + datalen;
576 	framelen = params_len + sizeof(framep->cmd) +
577 			     sizeof(framep->be_length);
578 
579 	framep->cmd = PN544_FW_CMD_WRITE;
580 
581 	put_unaligned_be16(params_len, &framep->be_length);
582 
583 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
584 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
585 	framep->be_dest_addr[2] = dest_addr & 0xff;
586 
587 	put_unaligned_be16(datalen, &framep->be_datalen);
588 
589 	memcpy(framep->data, data, datalen);
590 
591 	r = i2c_master_send(client, frame, framelen);
592 
593 	if (r == framelen)
594 		return datalen;
595 	else if (r < 0)
596 		return r;
597 	else
598 		return -EIO;
599 }
600 
601 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
602 				      const u8 *data, u16 datalen)
603 {
604 	struct pn544_i2c_fw_frame_check frame;
605 	int r;
606 	u16 crc;
607 
608 	/* calculate local crc for the data we want to check */
609 	crc = crc_ccitt(0xffff, data, datalen);
610 
611 	frame.cmd = PN544_FW_CMD_CHECK;
612 
613 	put_unaligned_be16(sizeof(frame.be_start_addr) +
614 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
615 			   &frame.be_length);
616 
617 	/* tell the chip the memory region to which our crc applies */
618 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
619 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
620 	frame.be_start_addr[2] = start_addr & 0xff;
621 
622 	put_unaligned_be16(datalen, &frame.be_datalen);
623 
624 	/*
625 	 * and give our local crc. Chip will calculate its own crc for the
626 	 * region and compare with ours.
627 	 */
628 	put_unaligned_be16(crc, &frame.be_crc);
629 
630 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
631 
632 	if (r == sizeof(frame))
633 		return 0;
634 	else if (r < 0)
635 		return r;
636 	else
637 		return -EIO;
638 }
639 
640 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
641 {
642 	int r;
643 
644 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
645 				       phy->fw_blob_dest_addr + phy->fw_written,
646 				       phy->fw_blob_data + phy->fw_written,
647 				       phy->fw_blob_size - phy->fw_written);
648 	if (r < 0)
649 		return r;
650 
651 	phy->fw_written += r;
652 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
653 
654 	return 0;
655 }
656 
657 static int pn544_hci_i2c_fw_secure_write_frame_cmd(struct pn544_i2c_phy *phy,
658 					const u8 *data, u16 datalen)
659 {
660 	u8 buf[PN544_FW_I2C_MAX_PAYLOAD];
661 	struct pn544_i2c_fw_secure_frame *chunk;
662 	int chunklen;
663 	int r;
664 
665 	if (datalen > PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN)
666 		datalen = PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN;
667 
668 	chunk = (struct pn544_i2c_fw_secure_frame *) buf;
669 
670 	chunk->cmd = PN544_FW_CMD_SECURE_CHUNK_WRITE;
671 
672 	put_unaligned_be16(datalen, &chunk->be_datalen);
673 
674 	memcpy(chunk->data, data, datalen);
675 
676 	chunklen = sizeof(chunk->cmd) + sizeof(chunk->be_datalen) + datalen;
677 
678 	r = i2c_master_send(phy->i2c_dev, buf, chunklen);
679 
680 	if (r == chunklen)
681 		return datalen;
682 	else if (r < 0)
683 		return r;
684 	else
685 		return -EIO;
686 
687 }
688 
689 static int pn544_hci_i2c_fw_secure_write_frame(struct pn544_i2c_phy *phy)
690 {
691 	struct pn544_i2c_fw_secure_frame *framep;
692 	int r;
693 
694 	framep = (struct pn544_i2c_fw_secure_frame *) phy->fw_blob_data;
695 	if (phy->fw_written == 0)
696 		phy->fw_blob_size = get_unaligned_be16(&framep->be_datalen)
697 				+ PN544_FW_SECURE_FRAME_HEADER_LEN;
698 
699 	/* Only secure write command can be chunked*/
700 	if (phy->fw_blob_size > PN544_FW_I2C_MAX_PAYLOAD &&
701 			framep->cmd != PN544_FW_CMD_SECURE_WRITE)
702 		return -EINVAL;
703 
704 	/* The firmware also have other commands, we just send them directly */
705 	if (phy->fw_blob_size < PN544_FW_I2C_MAX_PAYLOAD) {
706 		r = i2c_master_send(phy->i2c_dev,
707 			(const char *) phy->fw_blob_data, phy->fw_blob_size);
708 
709 		if (r == phy->fw_blob_size)
710 			goto exit;
711 		else if (r < 0)
712 			return r;
713 		else
714 			return -EIO;
715 	}
716 
717 	r = pn544_hci_i2c_fw_secure_write_frame_cmd(phy,
718 				       phy->fw_blob_data + phy->fw_written,
719 				       phy->fw_blob_size - phy->fw_written);
720 	if (r < 0)
721 		return r;
722 
723 exit:
724 	phy->fw_written += r;
725 	phy->fw_work_state = FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER;
726 
727 	/* SW reset command will not trig any response from PN544 */
728 	if (framep->cmd == PN544_FW_CMD_RESET) {
729 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
730 		phy->fw_cmd_result = 0;
731 		schedule_work(&phy->fw_work);
732 	}
733 
734 	return 0;
735 }
736 
737 static void pn544_hci_i2c_fw_work(struct work_struct *work)
738 {
739 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
740 						fw_work);
741 	int r;
742 	struct pn544_i2c_fw_blob *blob;
743 	struct pn544_i2c_fw_secure_blob *secure_blob;
744 
745 	switch (phy->fw_work_state) {
746 	case FW_WORK_STATE_START:
747 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
748 
749 		r = request_firmware(&phy->fw, phy->firmware_name,
750 				     &phy->i2c_dev->dev);
751 		if (r < 0)
752 			goto exit_state_start;
753 
754 		phy->fw_written = 0;
755 
756 		switch (phy->hw_variant) {
757 		case PN544_HW_VARIANT_C2:
758 			blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
759 			phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
760 			phy->fw_blob_dest_addr = get_unaligned_be32(
761 							&blob->be_destaddr);
762 			phy->fw_blob_data = blob->data;
763 
764 			r = pn544_hci_i2c_fw_write_chunk(phy);
765 			break;
766 		case PN544_HW_VARIANT_C3:
767 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
768 								phy->fw->data;
769 			phy->fw_blob_data = secure_blob->data;
770 			phy->fw_size = phy->fw->size;
771 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
772 			break;
773 		default:
774 			r = -ENOTSUPP;
775 			break;
776 		}
777 
778 exit_state_start:
779 		if (r < 0)
780 			pn544_hci_i2c_fw_work_complete(phy, r);
781 		break;
782 
783 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
784 		r = phy->fw_cmd_result;
785 		if (r < 0)
786 			goto exit_state_wait_write_answer;
787 
788 		if (phy->fw_written == phy->fw_blob_size) {
789 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
790 						       phy->fw_blob_dest_addr,
791 						       phy->fw_blob_data,
792 						       phy->fw_blob_size);
793 			if (r < 0)
794 				goto exit_state_wait_write_answer;
795 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
796 			break;
797 		}
798 
799 		r = pn544_hci_i2c_fw_write_chunk(phy);
800 
801 exit_state_wait_write_answer:
802 		if (r < 0)
803 			pn544_hci_i2c_fw_work_complete(phy, r);
804 		break;
805 
806 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
807 		r = phy->fw_cmd_result;
808 		if (r < 0)
809 			goto exit_state_wait_check_answer;
810 
811 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
812 		       phy->fw_blob_size);
813 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
814 		if (phy->fw_blob_size != 0) {
815 			phy->fw_blob_dest_addr =
816 					get_unaligned_be32(&blob->be_destaddr);
817 			phy->fw_blob_data = blob->data;
818 
819 			phy->fw_written = 0;
820 			r = pn544_hci_i2c_fw_write_chunk(phy);
821 		}
822 
823 exit_state_wait_check_answer:
824 		if (r < 0 || phy->fw_blob_size == 0)
825 			pn544_hci_i2c_fw_work_complete(phy, r);
826 		break;
827 
828 	case FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER:
829 		r = phy->fw_cmd_result;
830 		if (r < 0)
831 			goto exit_state_wait_secure_write_answer;
832 
833 		if (r == PN544_FW_CMD_RESULT_CHUNK_OK) {
834 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
835 			goto exit_state_wait_secure_write_answer;
836 		}
837 
838 		if (phy->fw_written == phy->fw_blob_size) {
839 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
840 				(phy->fw_blob_data + phy->fw_blob_size);
841 			phy->fw_size -= phy->fw_blob_size +
842 				PN544_FW_SECURE_BLOB_HEADER_LEN;
843 			if (phy->fw_size >= PN544_FW_SECURE_BLOB_HEADER_LEN
844 					+ PN544_FW_SECURE_FRAME_HEADER_LEN) {
845 				phy->fw_blob_data = secure_blob->data;
846 
847 				phy->fw_written = 0;
848 				r = pn544_hci_i2c_fw_secure_write_frame(phy);
849 			}
850 		}
851 
852 exit_state_wait_secure_write_answer:
853 		if (r < 0 || phy->fw_size == 0)
854 			pn544_hci_i2c_fw_work_complete(phy, r);
855 		break;
856 
857 	default:
858 		break;
859 	}
860 }
861 
862 #ifdef CONFIG_OF
863 
864 static int pn544_hci_i2c_of_request_resources(struct i2c_client *client)
865 {
866 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
867 	struct device_node *pp;
868 	int ret;
869 
870 	pp = client->dev.of_node;
871 	if (!pp) {
872 		ret = -ENODEV;
873 		goto err_dt;
874 	}
875 
876 	/* Obtention of EN GPIO from device tree */
877 	ret = of_get_named_gpio(pp, "enable-gpios", 0);
878 	if (ret < 0) {
879 		if (ret != -EPROBE_DEFER)
880 			nfc_err(&client->dev,
881 				"Failed to get EN gpio, error: %d\n", ret);
882 		goto err_dt;
883 	}
884 	phy->gpio_en = ret;
885 
886 	/* Configuration of EN GPIO */
887 	ret = gpio_request(phy->gpio_en, "pn544_en");
888 	if (ret) {
889 		nfc_err(&client->dev, "Fail EN pin\n");
890 		goto err_dt;
891 	}
892 	ret = gpio_direction_output(phy->gpio_en, 0);
893 	if (ret) {
894 		nfc_err(&client->dev, "Fail EN pin direction\n");
895 		goto err_gpio_en;
896 	}
897 
898 	/* Obtention of FW GPIO from device tree */
899 	ret = of_get_named_gpio(pp, "firmware-gpios", 0);
900 	if (ret < 0) {
901 		if (ret != -EPROBE_DEFER)
902 			nfc_err(&client->dev,
903 				"Failed to get FW gpio, error: %d\n", ret);
904 		goto err_gpio_en;
905 	}
906 	phy->gpio_fw = ret;
907 
908 	/* Configuration of FW GPIO */
909 	ret = gpio_request(phy->gpio_fw, "pn544_fw");
910 	if (ret) {
911 		nfc_err(&client->dev, "Fail FW pin\n");
912 		goto err_gpio_en;
913 	}
914 	ret = gpio_direction_output(phy->gpio_fw, 0);
915 	if (ret) {
916 		nfc_err(&client->dev, "Fail FW pin direction\n");
917 		goto err_gpio_fw;
918 	}
919 
920 	/* IRQ */
921 	ret = irq_of_parse_and_map(pp, 0);
922 	if (ret < 0) {
923 		nfc_err(&client->dev,
924 			"Unable to get irq, error: %d\n", ret);
925 		goto err_gpio_fw;
926 	}
927 	client->irq = ret;
928 
929 	return 0;
930 
931 err_gpio_fw:
932 	gpio_free(phy->gpio_fw);
933 err_gpio_en:
934 	gpio_free(phy->gpio_en);
935 err_dt:
936 	return ret;
937 }
938 
939 #else
940 
941 static int pn544_hci_i2c_of_request_resources(struct i2c_client *client)
942 {
943 	return -ENODEV;
944 }
945 
946 #endif
947 
948 static int pn544_hci_i2c_probe(struct i2c_client *client,
949 			       const struct i2c_device_id *id)
950 {
951 	struct pn544_i2c_phy *phy;
952 	struct pn544_nfc_platform_data *pdata;
953 	int r = 0;
954 
955 	dev_dbg(&client->dev, "%s\n", __func__);
956 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
957 
958 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
959 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
960 		return -ENODEV;
961 	}
962 
963 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
964 			   GFP_KERNEL);
965 	if (!phy) {
966 		nfc_err(&client->dev,
967 			"Cannot allocate memory for pn544 i2c phy.\n");
968 		return -ENOMEM;
969 	}
970 
971 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
972 	phy->fw_work_state = FW_WORK_STATE_IDLE;
973 
974 	phy->i2c_dev = client;
975 	i2c_set_clientdata(client, phy);
976 
977 	pdata = client->dev.platform_data;
978 
979 	/* No platform data, using device tree. */
980 	if (!pdata && client->dev.of_node) {
981 		r = pn544_hci_i2c_of_request_resources(client);
982 		if (r) {
983 			nfc_err(&client->dev, "No DT data\n");
984 			return r;
985 		}
986 	/* Using platform data. */
987 	} else if (pdata) {
988 
989 		if (pdata->request_resources == NULL) {
990 			nfc_err(&client->dev, "request_resources() missing\n");
991 			return -EINVAL;
992 		}
993 
994 		r = pdata->request_resources(client);
995 		if (r) {
996 			nfc_err(&client->dev,
997 				"Cannot get platform resources\n");
998 			return r;
999 		}
1000 
1001 		phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
1002 		phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
1003 		phy->gpio_irq = pdata->get_gpio(NFC_GPIO_IRQ);
1004 	} else {
1005 		nfc_err(&client->dev, "No platform data\n");
1006 		return -EINVAL;
1007 	}
1008 
1009 	pn544_hci_i2c_platform_init(phy);
1010 
1011 	r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
1012 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1013 				 PN544_HCI_I2C_DRIVER_NAME, phy);
1014 	if (r < 0) {
1015 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
1016 		goto err_rti;
1017 	}
1018 
1019 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
1020 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
1021 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
1022 			    pn544_hci_i2c_fw_download, &phy->hdev);
1023 	if (r < 0)
1024 		goto err_hci;
1025 
1026 	return 0;
1027 
1028 err_hci:
1029 	free_irq(client->irq, phy);
1030 
1031 err_rti:
1032 	if (!pdata) {
1033 		gpio_free(phy->gpio_en);
1034 		gpio_free(phy->gpio_fw);
1035 	} else if (pdata->free_resources) {
1036 		pdata->free_resources();
1037 	}
1038 
1039 	return r;
1040 }
1041 
1042 static int pn544_hci_i2c_remove(struct i2c_client *client)
1043 {
1044 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
1045 	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
1046 
1047 	dev_dbg(&client->dev, "%s\n", __func__);
1048 
1049 	cancel_work_sync(&phy->fw_work);
1050 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
1051 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
1052 
1053 	pn544_hci_remove(phy->hdev);
1054 
1055 	if (phy->powered)
1056 		pn544_hci_i2c_disable(phy);
1057 
1058 	free_irq(client->irq, phy);
1059 
1060 	/* No platform data, GPIOs have been requested by this driver */
1061 	if (!pdata) {
1062 		gpio_free(phy->gpio_en);
1063 		gpio_free(phy->gpio_fw);
1064 	/* Using platform data */
1065 	} else if (pdata->free_resources) {
1066 		pdata->free_resources();
1067 	}
1068 
1069 	return 0;
1070 }
1071 
1072 static const struct of_device_id of_pn544_i2c_match[] = {
1073 	{ .compatible = "nxp,pn544-i2c", },
1074 	{},
1075 };
1076 MODULE_DEVICE_TABLE(of, of_pn544_i2c_match);
1077 
1078 static struct i2c_driver pn544_hci_i2c_driver = {
1079 	.driver = {
1080 		   .name = PN544_HCI_I2C_DRIVER_NAME,
1081 		   .owner  = THIS_MODULE,
1082 		   .of_match_table = of_match_ptr(of_pn544_i2c_match),
1083 		  },
1084 	.probe = pn544_hci_i2c_probe,
1085 	.id_table = pn544_hci_i2c_id_table,
1086 	.remove = pn544_hci_i2c_remove,
1087 };
1088 
1089 module_i2c_driver(pn544_hci_i2c_driver);
1090 
1091 MODULE_LICENSE("GPL");
1092 MODULE_DESCRIPTION(DRIVER_DESC);
1093