xref: /openbmc/linux/drivers/nfc/pn544/i2c.c (revision d3964221)
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/acpi.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/nfc.h>
28 #include <linux/firmware.h>
29 #include <linux/gpio/consumer.h>
30 
31 #include <asm/unaligned.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 /* GPIO names */
43 #define PN544_GPIO_NAME_IRQ "pn544_irq"
44 #define PN544_GPIO_NAME_FW  "pn544_fw"
45 #define PN544_GPIO_NAME_EN  "pn544_en"
46 
47 /* framing in HCI mode */
48 #define PN544_HCI_I2C_LLC_LEN		1
49 #define PN544_HCI_I2C_LLC_CRC		2
50 #define PN544_HCI_I2C_LLC_LEN_CRC	(PN544_HCI_I2C_LLC_LEN + \
51 					 PN544_HCI_I2C_LLC_CRC)
52 #define PN544_HCI_I2C_LLC_MIN_SIZE	(1 + PN544_HCI_I2C_LLC_LEN_CRC)
53 #define PN544_HCI_I2C_LLC_MAX_PAYLOAD	29
54 #define PN544_HCI_I2C_LLC_MAX_SIZE	(PN544_HCI_I2C_LLC_LEN_CRC + 1 + \
55 					 PN544_HCI_I2C_LLC_MAX_PAYLOAD)
56 
57 static struct i2c_device_id pn544_hci_i2c_id_table[] = {
58 	{"pn544", 0},
59 	{}
60 };
61 
62 MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);
63 
64 static const struct acpi_device_id pn544_hci_i2c_acpi_match[] = {
65 	{"NXP5440", 0},
66 	{}
67 };
68 
69 MODULE_DEVICE_TABLE(acpi, pn544_hci_i2c_acpi_match);
70 
71 #define PN544_HCI_I2C_DRIVER_NAME "pn544_hci_i2c"
72 
73 /*
74  * Exposed through the 4 most significant bytes
75  * from the HCI SW_VERSION first byte, a.k.a.
76  * SW RomLib.
77  */
78 #define PN544_HW_VARIANT_C2 0xa
79 #define PN544_HW_VARIANT_C3 0xb
80 
81 #define PN544_FW_CMD_RESET 0x01
82 #define PN544_FW_CMD_WRITE 0x08
83 #define PN544_FW_CMD_CHECK 0x06
84 #define PN544_FW_CMD_SECURE_WRITE 0x0C
85 #define PN544_FW_CMD_SECURE_CHUNK_WRITE 0x0D
86 
87 struct pn544_i2c_fw_frame_write {
88 	u8 cmd;
89 	u16 be_length;
90 	u8 be_dest_addr[3];
91 	u16 be_datalen;
92 	u8 data[];
93 } __packed;
94 
95 struct pn544_i2c_fw_frame_check {
96 	u8 cmd;
97 	u16 be_length;
98 	u8 be_start_addr[3];
99 	u16 be_datalen;
100 	u16 be_crc;
101 } __packed;
102 
103 struct pn544_i2c_fw_frame_response {
104 	u8 status;
105 	u16 be_length;
106 } __packed;
107 
108 struct pn544_i2c_fw_blob {
109 	u32 be_size;
110 	u32 be_destaddr;
111 	u8 data[];
112 };
113 
114 struct pn544_i2c_fw_secure_frame {
115 	u8 cmd;
116 	u16 be_datalen;
117 	u8 data[];
118 } __packed;
119 
120 struct pn544_i2c_fw_secure_blob {
121 	u64 header;
122 	u8 data[];
123 };
124 
125 #define PN544_FW_CMD_RESULT_TIMEOUT 0x01
126 #define PN544_FW_CMD_RESULT_BAD_CRC 0x02
127 #define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
128 #define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
129 #define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
130 #define PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND 0x13
131 #define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
132 #define PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR 0x19
133 #define PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR 0x1D
134 #define PN544_FW_CMD_RESULT_MEMORY_ERROR 0x20
135 #define PN544_FW_CMD_RESULT_CHUNK_OK 0x21
136 #define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
137 #define PN544_FW_CMD_RESULT_COMMAND_REJECTED 0xE0
138 #define PN544_FW_CMD_RESULT_CHUNK_ERROR 0xE6
139 
140 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
141 
142 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
143 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
144 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
145 #define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
146 					 PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
147 					 PN544_FW_WRITE_BUFFER_MAX_LEN)
148 #define PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN 3
149 #define PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN (PN544_FW_I2C_MAX_PAYLOAD -\
150 			PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN)
151 #define PN544_FW_SECURE_FRAME_HEADER_LEN 3
152 #define PN544_FW_SECURE_BLOB_HEADER_LEN 8
153 
154 #define FW_WORK_STATE_IDLE 1
155 #define FW_WORK_STATE_START 2
156 #define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
157 #define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
158 #define FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER 5
159 
160 struct pn544_i2c_phy {
161 	struct i2c_client *i2c_dev;
162 	struct nfc_hci_dev *hdev;
163 
164 	struct gpio_desc *gpiod_en;
165 	struct gpio_desc *gpiod_fw;
166 
167 	unsigned int en_polarity;
168 
169 	u8 hw_variant;
170 
171 	struct work_struct fw_work;
172 	int fw_work_state;
173 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
174 	const struct firmware *fw;
175 	u32 fw_blob_dest_addr;
176 	size_t fw_blob_size;
177 	const u8 *fw_blob_data;
178 	size_t fw_written;
179 	size_t fw_size;
180 
181 	int fw_cmd_result;
182 
183 	int powered;
184 	int run_mode;
185 
186 	int hard_fault;		/*
187 				 * < 0 if hardware error occured (e.g. i2c err)
188 				 * and prevents normal operation.
189 				 */
190 };
191 
192 #define I2C_DUMP_SKB(info, skb)					\
193 do {								\
194 	pr_debug("%s:\n", info);				\
195 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
196 		       16, 1, (skb)->data, (skb)->len, 0);	\
197 } while (0)
198 
199 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
200 {
201 	int polarity, retry, ret;
202 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
203 	int count = sizeof(rset_cmd);
204 
205 	nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
206 
207 	/* Disable fw download */
208 	gpiod_set_value_cansleep(phy->gpiod_fw, 0);
209 
210 	for (polarity = 0; polarity < 2; polarity++) {
211 		phy->en_polarity = polarity;
212 		retry = 3;
213 		while (retry--) {
214 			/* power off */
215 			gpiod_set_value_cansleep(phy->gpiod_en, !phy->en_polarity);
216 			usleep_range(10000, 15000);
217 
218 			/* power on */
219 			gpiod_set_value_cansleep(phy->gpiod_en, phy->en_polarity);
220 			usleep_range(10000, 15000);
221 
222 			/* send reset */
223 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
224 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
225 			if (ret == count) {
226 				nfc_info(&phy->i2c_dev->dev,
227 					 "nfc_en polarity : active %s\n",
228 					 (polarity == 0 ? "low" : "high"));
229 				goto out;
230 			}
231 		}
232 	}
233 
234 	nfc_err(&phy->i2c_dev->dev,
235 		"Could not detect nfc_en polarity, fallback to active high\n");
236 
237 out:
238 	gpiod_set_value_cansleep(phy->gpiod_en, !phy->en_polarity);
239 }
240 
241 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
242 {
243 	gpiod_set_value_cansleep(phy->gpiod_fw, run_mode == PN544_FW_MODE ? 1 : 0);
244 	gpiod_set_value_cansleep(phy->gpiod_en, phy->en_polarity);
245 	usleep_range(10000, 15000);
246 
247 	phy->run_mode = run_mode;
248 }
249 
250 static int pn544_hci_i2c_enable(void *phy_id)
251 {
252 	struct pn544_i2c_phy *phy = phy_id;
253 
254 	pr_info("%s\n", __func__);
255 
256 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
257 
258 	phy->powered = 1;
259 
260 	return 0;
261 }
262 
263 static void pn544_hci_i2c_disable(void *phy_id)
264 {
265 	struct pn544_i2c_phy *phy = phy_id;
266 
267 	gpiod_set_value_cansleep(phy->gpiod_fw, 0);
268 	gpiod_set_value_cansleep(phy->gpiod_en, !phy->en_polarity);
269 	usleep_range(10000, 15000);
270 
271 	gpiod_set_value_cansleep(phy->gpiod_en, phy->en_polarity);
272 	usleep_range(10000, 15000);
273 
274 	gpiod_set_value_cansleep(phy->gpiod_en, !phy->en_polarity);
275 	usleep_range(10000, 15000);
276 
277 	phy->powered = 0;
278 }
279 
280 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
281 {
282 	u16 crc;
283 	int len;
284 
285 	len = skb->len + 2;
286 	*(u8 *)skb_push(skb, 1) = len;
287 
288 	crc = crc_ccitt(0xffff, skb->data, skb->len);
289 	crc = ~crc;
290 	skb_put_u8(skb, crc & 0xff);
291 	skb_put_u8(skb, crc >> 8);
292 }
293 
294 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
295 {
296 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
297 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
298 }
299 
300 /*
301  * Writing a frame must not return the number of written bytes.
302  * It must return either zero for success, or <0 for error.
303  * In addition, it must not alter the skb
304  */
305 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
306 {
307 	int r;
308 	struct pn544_i2c_phy *phy = phy_id;
309 	struct i2c_client *client = phy->i2c_dev;
310 
311 	if (phy->hard_fault != 0)
312 		return phy->hard_fault;
313 
314 	usleep_range(3000, 6000);
315 
316 	pn544_hci_i2c_add_len_crc(skb);
317 
318 	I2C_DUMP_SKB("i2c frame written", skb);
319 
320 	r = i2c_master_send(client, skb->data, skb->len);
321 
322 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
323 		usleep_range(6000, 10000);
324 		r = i2c_master_send(client, skb->data, skb->len);
325 	}
326 
327 	if (r >= 0) {
328 		if (r != skb->len)
329 			r = -EREMOTEIO;
330 		else
331 			r = 0;
332 	}
333 
334 	pn544_hci_i2c_remove_len_crc(skb);
335 
336 	return r;
337 }
338 
339 static int check_crc(u8 *buf, int buflen)
340 {
341 	int len;
342 	u16 crc;
343 
344 	len = buf[0] + 1;
345 	crc = crc_ccitt(0xffff, buf, len - 2);
346 	crc = ~crc;
347 
348 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
349 		pr_err("CRC error 0x%x != 0x%x 0x%x\n",
350 		       crc, buf[len - 1], buf[len - 2]);
351 		pr_info("%s: BAD CRC\n", __func__);
352 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
353 			       16, 2, buf, buflen, false);
354 		return -EPERM;
355 	}
356 	return 0;
357 }
358 
359 /*
360  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
361  * that i2c bus will be flushed and that next read will start on a new frame.
362  * returned skb contains only LLC header and payload.
363  * returns:
364  * -EREMOTEIO : i2c read error (fatal)
365  * -EBADMSG : frame was incorrect and discarded
366  * -ENOMEM : cannot allocate skb, frame dropped
367  */
368 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
369 {
370 	int r;
371 	u8 len;
372 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
373 	struct i2c_client *client = phy->i2c_dev;
374 
375 	r = i2c_master_recv(client, &len, 1);
376 	if (r != 1) {
377 		nfc_err(&client->dev, "cannot read len byte\n");
378 		return -EREMOTEIO;
379 	}
380 
381 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
382 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
383 		nfc_err(&client->dev, "invalid len byte\n");
384 		r = -EBADMSG;
385 		goto flush;
386 	}
387 
388 	*skb = alloc_skb(1 + len, GFP_KERNEL);
389 	if (*skb == NULL) {
390 		r = -ENOMEM;
391 		goto flush;
392 	}
393 
394 	skb_put_u8(*skb, len);
395 
396 	r = i2c_master_recv(client, skb_put(*skb, len), len);
397 	if (r != len) {
398 		kfree_skb(*skb);
399 		return -EREMOTEIO;
400 	}
401 
402 	I2C_DUMP_SKB("i2c frame read", *skb);
403 
404 	r = check_crc((*skb)->data, (*skb)->len);
405 	if (r != 0) {
406 		kfree_skb(*skb);
407 		r = -EBADMSG;
408 		goto flush;
409 	}
410 
411 	skb_pull(*skb, 1);
412 	skb_trim(*skb, (*skb)->len - 2);
413 
414 	usleep_range(3000, 6000);
415 
416 	return 0;
417 
418 flush:
419 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
420 		r = -EREMOTEIO;
421 
422 	usleep_range(3000, 6000);
423 
424 	return r;
425 }
426 
427 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
428 {
429 	int r;
430 	struct pn544_i2c_fw_frame_response response;
431 	struct i2c_client *client = phy->i2c_dev;
432 
433 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
434 	if (r != sizeof(response)) {
435 		nfc_err(&client->dev, "cannot read fw status\n");
436 		return -EIO;
437 	}
438 
439 	usleep_range(3000, 6000);
440 
441 	switch (response.status) {
442 	case 0:
443 		return 0;
444 	case PN544_FW_CMD_RESULT_CHUNK_OK:
445 		return response.status;
446 	case PN544_FW_CMD_RESULT_TIMEOUT:
447 		return -ETIMEDOUT;
448 	case PN544_FW_CMD_RESULT_BAD_CRC:
449 		return -ENODATA;
450 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
451 		return -EACCES;
452 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
453 		return -EPROTO;
454 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
455 		return -EINVAL;
456 	case PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND:
457 		return -ENOTSUPP;
458 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
459 		return -EBADMSG;
460 	case PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR:
461 		return -ENOKEY;
462 	case PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR:
463 		return -EINVAL;
464 	case PN544_FW_CMD_RESULT_MEMORY_ERROR:
465 		return -ENOMEM;
466 	case PN544_FW_CMD_RESULT_COMMAND_REJECTED:
467 		return -EACCES;
468 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
469 	case PN544_FW_CMD_RESULT_CHUNK_ERROR:
470 		return -EIO;
471 	default:
472 		return -EIO;
473 	}
474 }
475 
476 /*
477  * Reads an shdlc frame from the chip. This is not as straightforward as it
478  * seems. There are cases where we could loose the frame start synchronization.
479  * The frame format is len-data-crc, and corruption can occur anywhere while
480  * transiting on i2c bus, such that we could read an invalid len.
481  * In order to recover synchronization with the next frame, we must be sure
482  * to read the real amount of data without using the len byte. We do this by
483  * assuming the following:
484  * - the chip will always present only one single complete frame on the bus
485  *   before triggering the interrupt
486  * - the chip will not present a new frame until we have completely read
487  *   the previous one (or until we have handled the interrupt).
488  * The tricky case is when we read a corrupted len that is less than the real
489  * len. We must detect this here in order to determine that we need to flush
490  * the bus. This is the reason why we check the crc here.
491  */
492 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
493 {
494 	struct pn544_i2c_phy *phy = phy_id;
495 	struct i2c_client *client;
496 	struct sk_buff *skb = NULL;
497 	int r;
498 
499 	if (!phy || irq != phy->i2c_dev->irq) {
500 		WARN_ON_ONCE(1);
501 		return IRQ_NONE;
502 	}
503 
504 	client = phy->i2c_dev;
505 	dev_dbg(&client->dev, "IRQ\n");
506 
507 	if (phy->hard_fault != 0)
508 		return IRQ_HANDLED;
509 
510 	if (phy->run_mode == PN544_FW_MODE) {
511 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
512 		schedule_work(&phy->fw_work);
513 	} else {
514 		r = pn544_hci_i2c_read(phy, &skb);
515 		if (r == -EREMOTEIO) {
516 			phy->hard_fault = r;
517 
518 			nfc_hci_recv_frame(phy->hdev, NULL);
519 
520 			return IRQ_HANDLED;
521 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
522 			return IRQ_HANDLED;
523 		}
524 
525 		nfc_hci_recv_frame(phy->hdev, skb);
526 	}
527 	return IRQ_HANDLED;
528 }
529 
530 static struct nfc_phy_ops i2c_phy_ops = {
531 	.write = pn544_hci_i2c_write,
532 	.enable = pn544_hci_i2c_enable,
533 	.disable = pn544_hci_i2c_disable,
534 };
535 
536 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name,
537 					u8 hw_variant)
538 {
539 	struct pn544_i2c_phy *phy = phy_id;
540 
541 	pr_info("Starting Firmware Download (%s)\n", firmware_name);
542 
543 	strcpy(phy->firmware_name, firmware_name);
544 
545 	phy->hw_variant = hw_variant;
546 	phy->fw_work_state = FW_WORK_STATE_START;
547 
548 	schedule_work(&phy->fw_work);
549 
550 	return 0;
551 }
552 
553 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
554 					   int result)
555 {
556 	pr_info("Firmware Download Complete, result=%d\n", result);
557 
558 	pn544_hci_i2c_disable(phy);
559 
560 	phy->fw_work_state = FW_WORK_STATE_IDLE;
561 
562 	if (phy->fw) {
563 		release_firmware(phy->fw);
564 		phy->fw = NULL;
565 	}
566 
567 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
568 }
569 
570 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
571 				      const u8 *data, u16 datalen)
572 {
573 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
574 	struct pn544_i2c_fw_frame_write *framep;
575 	u16 params_len;
576 	int framelen;
577 	int r;
578 
579 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
580 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
581 
582 	framep = (struct pn544_i2c_fw_frame_write *) frame;
583 
584 	params_len = sizeof(framep->be_dest_addr) +
585 		     sizeof(framep->be_datalen) + datalen;
586 	framelen = params_len + sizeof(framep->cmd) +
587 			     sizeof(framep->be_length);
588 
589 	framep->cmd = PN544_FW_CMD_WRITE;
590 
591 	put_unaligned_be16(params_len, &framep->be_length);
592 
593 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
594 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
595 	framep->be_dest_addr[2] = dest_addr & 0xff;
596 
597 	put_unaligned_be16(datalen, &framep->be_datalen);
598 
599 	memcpy(framep->data, data, datalen);
600 
601 	r = i2c_master_send(client, frame, framelen);
602 
603 	if (r == framelen)
604 		return datalen;
605 	else if (r < 0)
606 		return r;
607 	else
608 		return -EIO;
609 }
610 
611 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
612 				      const u8 *data, u16 datalen)
613 {
614 	struct pn544_i2c_fw_frame_check frame;
615 	int r;
616 	u16 crc;
617 
618 	/* calculate local crc for the data we want to check */
619 	crc = crc_ccitt(0xffff, data, datalen);
620 
621 	frame.cmd = PN544_FW_CMD_CHECK;
622 
623 	put_unaligned_be16(sizeof(frame.be_start_addr) +
624 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
625 			   &frame.be_length);
626 
627 	/* tell the chip the memory region to which our crc applies */
628 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
629 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
630 	frame.be_start_addr[2] = start_addr & 0xff;
631 
632 	put_unaligned_be16(datalen, &frame.be_datalen);
633 
634 	/*
635 	 * and give our local crc. Chip will calculate its own crc for the
636 	 * region and compare with ours.
637 	 */
638 	put_unaligned_be16(crc, &frame.be_crc);
639 
640 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
641 
642 	if (r == sizeof(frame))
643 		return 0;
644 	else if (r < 0)
645 		return r;
646 	else
647 		return -EIO;
648 }
649 
650 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
651 {
652 	int r;
653 
654 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
655 				       phy->fw_blob_dest_addr + phy->fw_written,
656 				       phy->fw_blob_data + phy->fw_written,
657 				       phy->fw_blob_size - phy->fw_written);
658 	if (r < 0)
659 		return r;
660 
661 	phy->fw_written += r;
662 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
663 
664 	return 0;
665 }
666 
667 static int pn544_hci_i2c_fw_secure_write_frame_cmd(struct pn544_i2c_phy *phy,
668 					const u8 *data, u16 datalen)
669 {
670 	u8 buf[PN544_FW_I2C_MAX_PAYLOAD];
671 	struct pn544_i2c_fw_secure_frame *chunk;
672 	int chunklen;
673 	int r;
674 
675 	if (datalen > PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN)
676 		datalen = PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN;
677 
678 	chunk = (struct pn544_i2c_fw_secure_frame *) buf;
679 
680 	chunk->cmd = PN544_FW_CMD_SECURE_CHUNK_WRITE;
681 
682 	put_unaligned_be16(datalen, &chunk->be_datalen);
683 
684 	memcpy(chunk->data, data, datalen);
685 
686 	chunklen = sizeof(chunk->cmd) + sizeof(chunk->be_datalen) + datalen;
687 
688 	r = i2c_master_send(phy->i2c_dev, buf, chunklen);
689 
690 	if (r == chunklen)
691 		return datalen;
692 	else if (r < 0)
693 		return r;
694 	else
695 		return -EIO;
696 
697 }
698 
699 static int pn544_hci_i2c_fw_secure_write_frame(struct pn544_i2c_phy *phy)
700 {
701 	struct pn544_i2c_fw_secure_frame *framep;
702 	int r;
703 
704 	framep = (struct pn544_i2c_fw_secure_frame *) phy->fw_blob_data;
705 	if (phy->fw_written == 0)
706 		phy->fw_blob_size = get_unaligned_be16(&framep->be_datalen)
707 				+ PN544_FW_SECURE_FRAME_HEADER_LEN;
708 
709 	/* Only secure write command can be chunked*/
710 	if (phy->fw_blob_size > PN544_FW_I2C_MAX_PAYLOAD &&
711 			framep->cmd != PN544_FW_CMD_SECURE_WRITE)
712 		return -EINVAL;
713 
714 	/* The firmware also have other commands, we just send them directly */
715 	if (phy->fw_blob_size < PN544_FW_I2C_MAX_PAYLOAD) {
716 		r = i2c_master_send(phy->i2c_dev,
717 			(const char *) phy->fw_blob_data, phy->fw_blob_size);
718 
719 		if (r == phy->fw_blob_size)
720 			goto exit;
721 		else if (r < 0)
722 			return r;
723 		else
724 			return -EIO;
725 	}
726 
727 	r = pn544_hci_i2c_fw_secure_write_frame_cmd(phy,
728 				       phy->fw_blob_data + phy->fw_written,
729 				       phy->fw_blob_size - phy->fw_written);
730 	if (r < 0)
731 		return r;
732 
733 exit:
734 	phy->fw_written += r;
735 	phy->fw_work_state = FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER;
736 
737 	/* SW reset command will not trig any response from PN544 */
738 	if (framep->cmd == PN544_FW_CMD_RESET) {
739 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
740 		phy->fw_cmd_result = 0;
741 		schedule_work(&phy->fw_work);
742 	}
743 
744 	return 0;
745 }
746 
747 static void pn544_hci_i2c_fw_work(struct work_struct *work)
748 {
749 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
750 						fw_work);
751 	int r;
752 	struct pn544_i2c_fw_blob *blob;
753 	struct pn544_i2c_fw_secure_blob *secure_blob;
754 
755 	switch (phy->fw_work_state) {
756 	case FW_WORK_STATE_START:
757 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
758 
759 		r = request_firmware(&phy->fw, phy->firmware_name,
760 				     &phy->i2c_dev->dev);
761 		if (r < 0)
762 			goto exit_state_start;
763 
764 		phy->fw_written = 0;
765 
766 		switch (phy->hw_variant) {
767 		case PN544_HW_VARIANT_C2:
768 			blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
769 			phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
770 			phy->fw_blob_dest_addr = get_unaligned_be32(
771 							&blob->be_destaddr);
772 			phy->fw_blob_data = blob->data;
773 
774 			r = pn544_hci_i2c_fw_write_chunk(phy);
775 			break;
776 		case PN544_HW_VARIANT_C3:
777 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
778 								phy->fw->data;
779 			phy->fw_blob_data = secure_blob->data;
780 			phy->fw_size = phy->fw->size;
781 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
782 			break;
783 		default:
784 			r = -ENOTSUPP;
785 			break;
786 		}
787 
788 exit_state_start:
789 		if (r < 0)
790 			pn544_hci_i2c_fw_work_complete(phy, r);
791 		break;
792 
793 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
794 		r = phy->fw_cmd_result;
795 		if (r < 0)
796 			goto exit_state_wait_write_answer;
797 
798 		if (phy->fw_written == phy->fw_blob_size) {
799 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
800 						       phy->fw_blob_dest_addr,
801 						       phy->fw_blob_data,
802 						       phy->fw_blob_size);
803 			if (r < 0)
804 				goto exit_state_wait_write_answer;
805 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
806 			break;
807 		}
808 
809 		r = pn544_hci_i2c_fw_write_chunk(phy);
810 
811 exit_state_wait_write_answer:
812 		if (r < 0)
813 			pn544_hci_i2c_fw_work_complete(phy, r);
814 		break;
815 
816 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
817 		r = phy->fw_cmd_result;
818 		if (r < 0)
819 			goto exit_state_wait_check_answer;
820 
821 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
822 		       phy->fw_blob_size);
823 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
824 		if (phy->fw_blob_size != 0) {
825 			phy->fw_blob_dest_addr =
826 					get_unaligned_be32(&blob->be_destaddr);
827 			phy->fw_blob_data = blob->data;
828 
829 			phy->fw_written = 0;
830 			r = pn544_hci_i2c_fw_write_chunk(phy);
831 		}
832 
833 exit_state_wait_check_answer:
834 		if (r < 0 || phy->fw_blob_size == 0)
835 			pn544_hci_i2c_fw_work_complete(phy, r);
836 		break;
837 
838 	case FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER:
839 		r = phy->fw_cmd_result;
840 		if (r < 0)
841 			goto exit_state_wait_secure_write_answer;
842 
843 		if (r == PN544_FW_CMD_RESULT_CHUNK_OK) {
844 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
845 			goto exit_state_wait_secure_write_answer;
846 		}
847 
848 		if (phy->fw_written == phy->fw_blob_size) {
849 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
850 				(phy->fw_blob_data + phy->fw_blob_size);
851 			phy->fw_size -= phy->fw_blob_size +
852 				PN544_FW_SECURE_BLOB_HEADER_LEN;
853 			if (phy->fw_size >= PN544_FW_SECURE_BLOB_HEADER_LEN
854 					+ PN544_FW_SECURE_FRAME_HEADER_LEN) {
855 				phy->fw_blob_data = secure_blob->data;
856 
857 				phy->fw_written = 0;
858 				r = pn544_hci_i2c_fw_secure_write_frame(phy);
859 			}
860 		}
861 
862 exit_state_wait_secure_write_answer:
863 		if (r < 0 || phy->fw_size == 0)
864 			pn544_hci_i2c_fw_work_complete(phy, r);
865 		break;
866 
867 	default:
868 		break;
869 	}
870 }
871 
872 static const struct acpi_gpio_params enable_gpios = { 1, 0, false };
873 static const struct acpi_gpio_params firmware_gpios = { 2, 0, false };
874 
875 static const struct acpi_gpio_mapping acpi_pn544_gpios[] = {
876 	{ "enable-gpios", &enable_gpios, 1 },
877 	{ "firmware-gpios", &firmware_gpios, 1 },
878 	{ },
879 };
880 
881 static int pn544_hci_i2c_probe(struct i2c_client *client,
882 			       const struct i2c_device_id *id)
883 {
884 	struct device *dev = &client->dev;
885 	struct pn544_i2c_phy *phy;
886 	int r = 0;
887 
888 	dev_dbg(&client->dev, "%s\n", __func__);
889 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
890 
891 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
892 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
893 		return -ENODEV;
894 	}
895 
896 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
897 			   GFP_KERNEL);
898 	if (!phy)
899 		return -ENOMEM;
900 
901 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
902 	phy->fw_work_state = FW_WORK_STATE_IDLE;
903 
904 	phy->i2c_dev = client;
905 	i2c_set_clientdata(client, phy);
906 
907 	r = devm_acpi_dev_add_driver_gpios(dev, acpi_pn544_gpios);
908 	if (r)
909 		dev_dbg(dev, "Unable to add GPIO mapping table\n");
910 
911 	/* Get EN GPIO */
912 	phy->gpiod_en = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
913 	if (IS_ERR(phy->gpiod_en)) {
914 		nfc_err(dev, "Unable to get EN GPIO\n");
915 		return PTR_ERR(phy->gpiod_en);
916 	}
917 
918 	/* Get FW GPIO */
919 	phy->gpiod_fw = devm_gpiod_get(dev, "firmware", GPIOD_OUT_LOW);
920 	if (IS_ERR(phy->gpiod_fw)) {
921 		nfc_err(dev, "Unable to get FW GPIO\n");
922 		return PTR_ERR(phy->gpiod_fw);
923 	}
924 
925 	pn544_hci_i2c_platform_init(phy);
926 
927 	r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
928 				      pn544_hci_i2c_irq_thread_fn,
929 				      IRQF_TRIGGER_RISING | IRQF_ONESHOT,
930 				      PN544_HCI_I2C_DRIVER_NAME, phy);
931 	if (r < 0) {
932 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
933 		return r;
934 	}
935 
936 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
937 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
938 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
939 			    pn544_hci_i2c_fw_download, &phy->hdev);
940 	if (r < 0)
941 		return r;
942 
943 	return 0;
944 }
945 
946 static int pn544_hci_i2c_remove(struct i2c_client *client)
947 {
948 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
949 
950 	dev_dbg(&client->dev, "%s\n", __func__);
951 
952 	cancel_work_sync(&phy->fw_work);
953 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
954 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
955 
956 	pn544_hci_remove(phy->hdev);
957 
958 	if (phy->powered)
959 		pn544_hci_i2c_disable(phy);
960 
961 	return 0;
962 }
963 
964 static const struct of_device_id of_pn544_i2c_match[] = {
965 	{ .compatible = "nxp,pn544-i2c", },
966 	{},
967 };
968 MODULE_DEVICE_TABLE(of, of_pn544_i2c_match);
969 
970 static struct i2c_driver pn544_hci_i2c_driver = {
971 	.driver = {
972 		   .name = PN544_HCI_I2C_DRIVER_NAME,
973 		   .of_match_table = of_match_ptr(of_pn544_i2c_match),
974 		   .acpi_match_table = ACPI_PTR(pn544_hci_i2c_acpi_match),
975 		  },
976 	.probe = pn544_hci_i2c_probe,
977 	.id_table = pn544_hci_i2c_id_table,
978 	.remove = pn544_hci_i2c_remove,
979 };
980 
981 module_i2c_driver(pn544_hci_i2c_driver);
982 
983 MODULE_LICENSE("GPL");
984 MODULE_DESCRIPTION(DRIVER_DESC);
985