xref: /openbmc/linux/drivers/nfc/pn544/i2c.c (revision bc5aa3a0)
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/acpi.h>
28 #include <linux/miscdevice.h>
29 #include <linux/interrupt.h>
30 #include <linux/delay.h>
31 #include <linux/nfc.h>
32 #include <linux/firmware.h>
33 #include <linux/gpio/consumer.h>
34 #include <linux/platform_data/pn544.h>
35 #include <asm/unaligned.h>
36 
37 #include <net/nfc/hci.h>
38 #include <net/nfc/llc.h>
39 #include <net/nfc/nfc.h>
40 
41 #include "pn544.h"
42 
43 #define PN544_I2C_FRAME_HEADROOM 1
44 #define PN544_I2C_FRAME_TAILROOM 2
45 
46 /* GPIO names */
47 #define PN544_GPIO_NAME_IRQ "pn544_irq"
48 #define PN544_GPIO_NAME_FW  "pn544_fw"
49 #define PN544_GPIO_NAME_EN  "pn544_en"
50 
51 /* framing in HCI mode */
52 #define PN544_HCI_I2C_LLC_LEN		1
53 #define PN544_HCI_I2C_LLC_CRC		2
54 #define PN544_HCI_I2C_LLC_LEN_CRC	(PN544_HCI_I2C_LLC_LEN + \
55 					 PN544_HCI_I2C_LLC_CRC)
56 #define PN544_HCI_I2C_LLC_MIN_SIZE	(1 + PN544_HCI_I2C_LLC_LEN_CRC)
57 #define PN544_HCI_I2C_LLC_MAX_PAYLOAD	29
58 #define PN544_HCI_I2C_LLC_MAX_SIZE	(PN544_HCI_I2C_LLC_LEN_CRC + 1 + \
59 					 PN544_HCI_I2C_LLC_MAX_PAYLOAD)
60 
61 static struct i2c_device_id pn544_hci_i2c_id_table[] = {
62 	{"pn544", 0},
63 	{}
64 };
65 
66 MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);
67 
68 static const struct acpi_device_id pn544_hci_i2c_acpi_match[] = {
69 	{"NXP5440", 0},
70 	{}
71 };
72 
73 MODULE_DEVICE_TABLE(acpi, pn544_hci_i2c_acpi_match);
74 
75 #define PN544_HCI_I2C_DRIVER_NAME "pn544_hci_i2c"
76 
77 /*
78  * Exposed through the 4 most significant bytes
79  * from the HCI SW_VERSION first byte, a.k.a.
80  * SW RomLib.
81  */
82 #define PN544_HW_VARIANT_C2 0xa
83 #define PN544_HW_VARIANT_C3 0xb
84 
85 #define PN544_FW_CMD_RESET 0x01
86 #define PN544_FW_CMD_WRITE 0x08
87 #define PN544_FW_CMD_CHECK 0x06
88 #define PN544_FW_CMD_SECURE_WRITE 0x0C
89 #define PN544_FW_CMD_SECURE_CHUNK_WRITE 0x0D
90 
91 struct pn544_i2c_fw_frame_write {
92 	u8 cmd;
93 	u16 be_length;
94 	u8 be_dest_addr[3];
95 	u16 be_datalen;
96 	u8 data[];
97 } __packed;
98 
99 struct pn544_i2c_fw_frame_check {
100 	u8 cmd;
101 	u16 be_length;
102 	u8 be_start_addr[3];
103 	u16 be_datalen;
104 	u16 be_crc;
105 } __packed;
106 
107 struct pn544_i2c_fw_frame_response {
108 	u8 status;
109 	u16 be_length;
110 } __packed;
111 
112 struct pn544_i2c_fw_blob {
113 	u32 be_size;
114 	u32 be_destaddr;
115 	u8 data[];
116 };
117 
118 struct pn544_i2c_fw_secure_frame {
119 	u8 cmd;
120 	u16 be_datalen;
121 	u8 data[];
122 } __packed;
123 
124 struct pn544_i2c_fw_secure_blob {
125 	u64 header;
126 	u8 data[];
127 };
128 
129 #define PN544_FW_CMD_RESULT_TIMEOUT 0x01
130 #define PN544_FW_CMD_RESULT_BAD_CRC 0x02
131 #define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
132 #define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
133 #define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
134 #define PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND 0x13
135 #define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
136 #define PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR 0x19
137 #define PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR 0x1D
138 #define PN544_FW_CMD_RESULT_MEMORY_ERROR 0x20
139 #define PN544_FW_CMD_RESULT_CHUNK_OK 0x21
140 #define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
141 #define PN544_FW_CMD_RESULT_COMMAND_REJECTED 0xE0
142 #define PN544_FW_CMD_RESULT_CHUNK_ERROR 0xE6
143 
144 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
145 
146 #define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
147 #define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
148 #define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
149 #define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
150 					 PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
151 					 PN544_FW_WRITE_BUFFER_MAX_LEN)
152 #define PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN 3
153 #define PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN (PN544_FW_I2C_MAX_PAYLOAD -\
154 			PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN)
155 #define PN544_FW_SECURE_FRAME_HEADER_LEN 3
156 #define PN544_FW_SECURE_BLOB_HEADER_LEN 8
157 
158 #define FW_WORK_STATE_IDLE 1
159 #define FW_WORK_STATE_START 2
160 #define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
161 #define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
162 #define FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER 5
163 
164 struct pn544_i2c_phy {
165 	struct i2c_client *i2c_dev;
166 	struct nfc_hci_dev *hdev;
167 
168 	unsigned int gpio_en;
169 	unsigned int gpio_fw;
170 	unsigned int en_polarity;
171 
172 	u8 hw_variant;
173 
174 	struct work_struct fw_work;
175 	int fw_work_state;
176 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
177 	const struct firmware *fw;
178 	u32 fw_blob_dest_addr;
179 	size_t fw_blob_size;
180 	const u8 *fw_blob_data;
181 	size_t fw_written;
182 	size_t fw_size;
183 
184 	int fw_cmd_result;
185 
186 	int powered;
187 	int run_mode;
188 
189 	int hard_fault;		/*
190 				 * < 0 if hardware error occured (e.g. i2c err)
191 				 * and prevents normal operation.
192 				 */
193 };
194 
195 #define I2C_DUMP_SKB(info, skb)					\
196 do {								\
197 	pr_debug("%s:\n", info);				\
198 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
199 		       16, 1, (skb)->data, (skb)->len, 0);	\
200 } while (0)
201 
202 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
203 {
204 	int polarity, retry, ret;
205 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
206 	int count = sizeof(rset_cmd);
207 
208 	nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
209 
210 	/* Disable fw download */
211 	gpio_set_value_cansleep(phy->gpio_fw, 0);
212 
213 	for (polarity = 0; polarity < 2; polarity++) {
214 		phy->en_polarity = polarity;
215 		retry = 3;
216 		while (retry--) {
217 			/* power off */
218 			gpio_set_value_cansleep(phy->gpio_en,
219 						!phy->en_polarity);
220 			usleep_range(10000, 15000);
221 
222 			/* power on */
223 			gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
224 			usleep_range(10000, 15000);
225 
226 			/* send reset */
227 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
228 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
229 			if (ret == count) {
230 				nfc_info(&phy->i2c_dev->dev,
231 					 "nfc_en polarity : active %s\n",
232 					 (polarity == 0 ? "low" : "high"));
233 				goto out;
234 			}
235 		}
236 	}
237 
238 	nfc_err(&phy->i2c_dev->dev,
239 		"Could not detect nfc_en polarity, fallback to active high\n");
240 
241 out:
242 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
243 }
244 
245 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
246 {
247 	gpio_set_value_cansleep(phy->gpio_fw,
248 				run_mode == PN544_FW_MODE ? 1 : 0);
249 	gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
250 	usleep_range(10000, 15000);
251 
252 	phy->run_mode = run_mode;
253 }
254 
255 static int pn544_hci_i2c_enable(void *phy_id)
256 {
257 	struct pn544_i2c_phy *phy = phy_id;
258 
259 	pr_info("%s\n", __func__);
260 
261 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
262 
263 	phy->powered = 1;
264 
265 	return 0;
266 }
267 
268 static void pn544_hci_i2c_disable(void *phy_id)
269 {
270 	struct pn544_i2c_phy *phy = phy_id;
271 
272 	gpio_set_value_cansleep(phy->gpio_fw, 0);
273 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
274 	usleep_range(10000, 15000);
275 
276 	gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
277 	usleep_range(10000, 15000);
278 
279 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
280 	usleep_range(10000, 15000);
281 
282 	phy->powered = 0;
283 }
284 
285 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
286 {
287 	u16 crc;
288 	int len;
289 
290 	len = skb->len + 2;
291 	*skb_push(skb, 1) = len;
292 
293 	crc = crc_ccitt(0xffff, skb->data, skb->len);
294 	crc = ~crc;
295 	*skb_put(skb, 1) = crc & 0xff;
296 	*skb_put(skb, 1) = crc >> 8;
297 }
298 
299 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
300 {
301 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
302 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
303 }
304 
305 /*
306  * Writing a frame must not return the number of written bytes.
307  * It must return either zero for success, or <0 for error.
308  * In addition, it must not alter the skb
309  */
310 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
311 {
312 	int r;
313 	struct pn544_i2c_phy *phy = phy_id;
314 	struct i2c_client *client = phy->i2c_dev;
315 
316 	if (phy->hard_fault != 0)
317 		return phy->hard_fault;
318 
319 	usleep_range(3000, 6000);
320 
321 	pn544_hci_i2c_add_len_crc(skb);
322 
323 	I2C_DUMP_SKB("i2c frame written", skb);
324 
325 	r = i2c_master_send(client, skb->data, skb->len);
326 
327 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
328 		usleep_range(6000, 10000);
329 		r = i2c_master_send(client, skb->data, skb->len);
330 	}
331 
332 	if (r >= 0) {
333 		if (r != skb->len)
334 			r = -EREMOTEIO;
335 		else
336 			r = 0;
337 	}
338 
339 	pn544_hci_i2c_remove_len_crc(skb);
340 
341 	return r;
342 }
343 
344 static int check_crc(u8 *buf, int buflen)
345 {
346 	int len;
347 	u16 crc;
348 
349 	len = buf[0] + 1;
350 	crc = crc_ccitt(0xffff, buf, len - 2);
351 	crc = ~crc;
352 
353 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
354 		pr_err("CRC error 0x%x != 0x%x 0x%x\n",
355 		       crc, buf[len - 1], buf[len - 2]);
356 		pr_info("%s: BAD CRC\n", __func__);
357 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
358 			       16, 2, buf, buflen, false);
359 		return -EPERM;
360 	}
361 	return 0;
362 }
363 
364 /*
365  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
366  * that i2c bus will be flushed and that next read will start on a new frame.
367  * returned skb contains only LLC header and payload.
368  * returns:
369  * -EREMOTEIO : i2c read error (fatal)
370  * -EBADMSG : frame was incorrect and discarded
371  * -ENOMEM : cannot allocate skb, frame dropped
372  */
373 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
374 {
375 	int r;
376 	u8 len;
377 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
378 	struct i2c_client *client = phy->i2c_dev;
379 
380 	r = i2c_master_recv(client, &len, 1);
381 	if (r != 1) {
382 		nfc_err(&client->dev, "cannot read len byte\n");
383 		return -EREMOTEIO;
384 	}
385 
386 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
387 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
388 		nfc_err(&client->dev, "invalid len byte\n");
389 		r = -EBADMSG;
390 		goto flush;
391 	}
392 
393 	*skb = alloc_skb(1 + len, GFP_KERNEL);
394 	if (*skb == NULL) {
395 		r = -ENOMEM;
396 		goto flush;
397 	}
398 
399 	*skb_put(*skb, 1) = len;
400 
401 	r = i2c_master_recv(client, skb_put(*skb, len), len);
402 	if (r != len) {
403 		kfree_skb(*skb);
404 		return -EREMOTEIO;
405 	}
406 
407 	I2C_DUMP_SKB("i2c frame read", *skb);
408 
409 	r = check_crc((*skb)->data, (*skb)->len);
410 	if (r != 0) {
411 		kfree_skb(*skb);
412 		r = -EBADMSG;
413 		goto flush;
414 	}
415 
416 	skb_pull(*skb, 1);
417 	skb_trim(*skb, (*skb)->len - 2);
418 
419 	usleep_range(3000, 6000);
420 
421 	return 0;
422 
423 flush:
424 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
425 		r = -EREMOTEIO;
426 
427 	usleep_range(3000, 6000);
428 
429 	return r;
430 }
431 
432 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
433 {
434 	int r;
435 	struct pn544_i2c_fw_frame_response response;
436 	struct i2c_client *client = phy->i2c_dev;
437 
438 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
439 	if (r != sizeof(response)) {
440 		nfc_err(&client->dev, "cannot read fw status\n");
441 		return -EIO;
442 	}
443 
444 	usleep_range(3000, 6000);
445 
446 	switch (response.status) {
447 	case 0:
448 		return 0;
449 	case PN544_FW_CMD_RESULT_CHUNK_OK:
450 		return response.status;
451 	case PN544_FW_CMD_RESULT_TIMEOUT:
452 		return -ETIMEDOUT;
453 	case PN544_FW_CMD_RESULT_BAD_CRC:
454 		return -ENODATA;
455 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
456 		return -EACCES;
457 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
458 		return -EPROTO;
459 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
460 		return -EINVAL;
461 	case PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND:
462 		return -ENOTSUPP;
463 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
464 		return -EBADMSG;
465 	case PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR:
466 		return -ENOKEY;
467 	case PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR:
468 		return -EINVAL;
469 	case PN544_FW_CMD_RESULT_MEMORY_ERROR:
470 		return -ENOMEM;
471 	case PN544_FW_CMD_RESULT_COMMAND_REJECTED:
472 		return -EACCES;
473 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
474 	case PN544_FW_CMD_RESULT_CHUNK_ERROR:
475 		return -EIO;
476 	default:
477 		return -EIO;
478 	}
479 }
480 
481 /*
482  * Reads an shdlc frame from the chip. This is not as straightforward as it
483  * seems. There are cases where we could loose the frame start synchronization.
484  * The frame format is len-data-crc, and corruption can occur anywhere while
485  * transiting on i2c bus, such that we could read an invalid len.
486  * In order to recover synchronization with the next frame, we must be sure
487  * to read the real amount of data without using the len byte. We do this by
488  * assuming the following:
489  * - the chip will always present only one single complete frame on the bus
490  *   before triggering the interrupt
491  * - the chip will not present a new frame until we have completely read
492  *   the previous one (or until we have handled the interrupt).
493  * The tricky case is when we read a corrupted len that is less than the real
494  * len. We must detect this here in order to determine that we need to flush
495  * the bus. This is the reason why we check the crc here.
496  */
497 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
498 {
499 	struct pn544_i2c_phy *phy = phy_id;
500 	struct i2c_client *client;
501 	struct sk_buff *skb = NULL;
502 	int r;
503 
504 	if (!phy || irq != phy->i2c_dev->irq) {
505 		WARN_ON_ONCE(1);
506 		return IRQ_NONE;
507 	}
508 
509 	client = phy->i2c_dev;
510 	dev_dbg(&client->dev, "IRQ\n");
511 
512 	if (phy->hard_fault != 0)
513 		return IRQ_HANDLED;
514 
515 	if (phy->run_mode == PN544_FW_MODE) {
516 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
517 		schedule_work(&phy->fw_work);
518 	} else {
519 		r = pn544_hci_i2c_read(phy, &skb);
520 		if (r == -EREMOTEIO) {
521 			phy->hard_fault = r;
522 
523 			nfc_hci_recv_frame(phy->hdev, NULL);
524 
525 			return IRQ_HANDLED;
526 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
527 			return IRQ_HANDLED;
528 		}
529 
530 		nfc_hci_recv_frame(phy->hdev, skb);
531 	}
532 	return IRQ_HANDLED;
533 }
534 
535 static struct nfc_phy_ops i2c_phy_ops = {
536 	.write = pn544_hci_i2c_write,
537 	.enable = pn544_hci_i2c_enable,
538 	.disable = pn544_hci_i2c_disable,
539 };
540 
541 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name,
542 					u8 hw_variant)
543 {
544 	struct pn544_i2c_phy *phy = phy_id;
545 
546 	pr_info("Starting Firmware Download (%s)\n", firmware_name);
547 
548 	strcpy(phy->firmware_name, firmware_name);
549 
550 	phy->hw_variant = hw_variant;
551 	phy->fw_work_state = FW_WORK_STATE_START;
552 
553 	schedule_work(&phy->fw_work);
554 
555 	return 0;
556 }
557 
558 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
559 					   int result)
560 {
561 	pr_info("Firmware Download Complete, result=%d\n", result);
562 
563 	pn544_hci_i2c_disable(phy);
564 
565 	phy->fw_work_state = FW_WORK_STATE_IDLE;
566 
567 	if (phy->fw) {
568 		release_firmware(phy->fw);
569 		phy->fw = NULL;
570 	}
571 
572 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
573 }
574 
575 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
576 				      const u8 *data, u16 datalen)
577 {
578 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
579 	struct pn544_i2c_fw_frame_write *framep;
580 	u16 params_len;
581 	int framelen;
582 	int r;
583 
584 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
585 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
586 
587 	framep = (struct pn544_i2c_fw_frame_write *) frame;
588 
589 	params_len = sizeof(framep->be_dest_addr) +
590 		     sizeof(framep->be_datalen) + datalen;
591 	framelen = params_len + sizeof(framep->cmd) +
592 			     sizeof(framep->be_length);
593 
594 	framep->cmd = PN544_FW_CMD_WRITE;
595 
596 	put_unaligned_be16(params_len, &framep->be_length);
597 
598 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
599 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
600 	framep->be_dest_addr[2] = dest_addr & 0xff;
601 
602 	put_unaligned_be16(datalen, &framep->be_datalen);
603 
604 	memcpy(framep->data, data, datalen);
605 
606 	r = i2c_master_send(client, frame, framelen);
607 
608 	if (r == framelen)
609 		return datalen;
610 	else if (r < 0)
611 		return r;
612 	else
613 		return -EIO;
614 }
615 
616 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
617 				      const u8 *data, u16 datalen)
618 {
619 	struct pn544_i2c_fw_frame_check frame;
620 	int r;
621 	u16 crc;
622 
623 	/* calculate local crc for the data we want to check */
624 	crc = crc_ccitt(0xffff, data, datalen);
625 
626 	frame.cmd = PN544_FW_CMD_CHECK;
627 
628 	put_unaligned_be16(sizeof(frame.be_start_addr) +
629 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
630 			   &frame.be_length);
631 
632 	/* tell the chip the memory region to which our crc applies */
633 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
634 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
635 	frame.be_start_addr[2] = start_addr & 0xff;
636 
637 	put_unaligned_be16(datalen, &frame.be_datalen);
638 
639 	/*
640 	 * and give our local crc. Chip will calculate its own crc for the
641 	 * region and compare with ours.
642 	 */
643 	put_unaligned_be16(crc, &frame.be_crc);
644 
645 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
646 
647 	if (r == sizeof(frame))
648 		return 0;
649 	else if (r < 0)
650 		return r;
651 	else
652 		return -EIO;
653 }
654 
655 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
656 {
657 	int r;
658 
659 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
660 				       phy->fw_blob_dest_addr + phy->fw_written,
661 				       phy->fw_blob_data + phy->fw_written,
662 				       phy->fw_blob_size - phy->fw_written);
663 	if (r < 0)
664 		return r;
665 
666 	phy->fw_written += r;
667 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
668 
669 	return 0;
670 }
671 
672 static int pn544_hci_i2c_fw_secure_write_frame_cmd(struct pn544_i2c_phy *phy,
673 					const u8 *data, u16 datalen)
674 {
675 	u8 buf[PN544_FW_I2C_MAX_PAYLOAD];
676 	struct pn544_i2c_fw_secure_frame *chunk;
677 	int chunklen;
678 	int r;
679 
680 	if (datalen > PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN)
681 		datalen = PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN;
682 
683 	chunk = (struct pn544_i2c_fw_secure_frame *) buf;
684 
685 	chunk->cmd = PN544_FW_CMD_SECURE_CHUNK_WRITE;
686 
687 	put_unaligned_be16(datalen, &chunk->be_datalen);
688 
689 	memcpy(chunk->data, data, datalen);
690 
691 	chunklen = sizeof(chunk->cmd) + sizeof(chunk->be_datalen) + datalen;
692 
693 	r = i2c_master_send(phy->i2c_dev, buf, chunklen);
694 
695 	if (r == chunklen)
696 		return datalen;
697 	else if (r < 0)
698 		return r;
699 	else
700 		return -EIO;
701 
702 }
703 
704 static int pn544_hci_i2c_fw_secure_write_frame(struct pn544_i2c_phy *phy)
705 {
706 	struct pn544_i2c_fw_secure_frame *framep;
707 	int r;
708 
709 	framep = (struct pn544_i2c_fw_secure_frame *) phy->fw_blob_data;
710 	if (phy->fw_written == 0)
711 		phy->fw_blob_size = get_unaligned_be16(&framep->be_datalen)
712 				+ PN544_FW_SECURE_FRAME_HEADER_LEN;
713 
714 	/* Only secure write command can be chunked*/
715 	if (phy->fw_blob_size > PN544_FW_I2C_MAX_PAYLOAD &&
716 			framep->cmd != PN544_FW_CMD_SECURE_WRITE)
717 		return -EINVAL;
718 
719 	/* The firmware also have other commands, we just send them directly */
720 	if (phy->fw_blob_size < PN544_FW_I2C_MAX_PAYLOAD) {
721 		r = i2c_master_send(phy->i2c_dev,
722 			(const char *) phy->fw_blob_data, phy->fw_blob_size);
723 
724 		if (r == phy->fw_blob_size)
725 			goto exit;
726 		else if (r < 0)
727 			return r;
728 		else
729 			return -EIO;
730 	}
731 
732 	r = pn544_hci_i2c_fw_secure_write_frame_cmd(phy,
733 				       phy->fw_blob_data + phy->fw_written,
734 				       phy->fw_blob_size - phy->fw_written);
735 	if (r < 0)
736 		return r;
737 
738 exit:
739 	phy->fw_written += r;
740 	phy->fw_work_state = FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER;
741 
742 	/* SW reset command will not trig any response from PN544 */
743 	if (framep->cmd == PN544_FW_CMD_RESET) {
744 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
745 		phy->fw_cmd_result = 0;
746 		schedule_work(&phy->fw_work);
747 	}
748 
749 	return 0;
750 }
751 
752 static void pn544_hci_i2c_fw_work(struct work_struct *work)
753 {
754 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
755 						fw_work);
756 	int r;
757 	struct pn544_i2c_fw_blob *blob;
758 	struct pn544_i2c_fw_secure_blob *secure_blob;
759 
760 	switch (phy->fw_work_state) {
761 	case FW_WORK_STATE_START:
762 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
763 
764 		r = request_firmware(&phy->fw, phy->firmware_name,
765 				     &phy->i2c_dev->dev);
766 		if (r < 0)
767 			goto exit_state_start;
768 
769 		phy->fw_written = 0;
770 
771 		switch (phy->hw_variant) {
772 		case PN544_HW_VARIANT_C2:
773 			blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
774 			phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
775 			phy->fw_blob_dest_addr = get_unaligned_be32(
776 							&blob->be_destaddr);
777 			phy->fw_blob_data = blob->data;
778 
779 			r = pn544_hci_i2c_fw_write_chunk(phy);
780 			break;
781 		case PN544_HW_VARIANT_C3:
782 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
783 								phy->fw->data;
784 			phy->fw_blob_data = secure_blob->data;
785 			phy->fw_size = phy->fw->size;
786 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
787 			break;
788 		default:
789 			r = -ENOTSUPP;
790 			break;
791 		}
792 
793 exit_state_start:
794 		if (r < 0)
795 			pn544_hci_i2c_fw_work_complete(phy, r);
796 		break;
797 
798 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
799 		r = phy->fw_cmd_result;
800 		if (r < 0)
801 			goto exit_state_wait_write_answer;
802 
803 		if (phy->fw_written == phy->fw_blob_size) {
804 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
805 						       phy->fw_blob_dest_addr,
806 						       phy->fw_blob_data,
807 						       phy->fw_blob_size);
808 			if (r < 0)
809 				goto exit_state_wait_write_answer;
810 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
811 			break;
812 		}
813 
814 		r = pn544_hci_i2c_fw_write_chunk(phy);
815 
816 exit_state_wait_write_answer:
817 		if (r < 0)
818 			pn544_hci_i2c_fw_work_complete(phy, r);
819 		break;
820 
821 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
822 		r = phy->fw_cmd_result;
823 		if (r < 0)
824 			goto exit_state_wait_check_answer;
825 
826 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
827 		       phy->fw_blob_size);
828 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
829 		if (phy->fw_blob_size != 0) {
830 			phy->fw_blob_dest_addr =
831 					get_unaligned_be32(&blob->be_destaddr);
832 			phy->fw_blob_data = blob->data;
833 
834 			phy->fw_written = 0;
835 			r = pn544_hci_i2c_fw_write_chunk(phy);
836 		}
837 
838 exit_state_wait_check_answer:
839 		if (r < 0 || phy->fw_blob_size == 0)
840 			pn544_hci_i2c_fw_work_complete(phy, r);
841 		break;
842 
843 	case FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER:
844 		r = phy->fw_cmd_result;
845 		if (r < 0)
846 			goto exit_state_wait_secure_write_answer;
847 
848 		if (r == PN544_FW_CMD_RESULT_CHUNK_OK) {
849 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
850 			goto exit_state_wait_secure_write_answer;
851 		}
852 
853 		if (phy->fw_written == phy->fw_blob_size) {
854 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
855 				(phy->fw_blob_data + phy->fw_blob_size);
856 			phy->fw_size -= phy->fw_blob_size +
857 				PN544_FW_SECURE_BLOB_HEADER_LEN;
858 			if (phy->fw_size >= PN544_FW_SECURE_BLOB_HEADER_LEN
859 					+ PN544_FW_SECURE_FRAME_HEADER_LEN) {
860 				phy->fw_blob_data = secure_blob->data;
861 
862 				phy->fw_written = 0;
863 				r = pn544_hci_i2c_fw_secure_write_frame(phy);
864 			}
865 		}
866 
867 exit_state_wait_secure_write_answer:
868 		if (r < 0 || phy->fw_size == 0)
869 			pn544_hci_i2c_fw_work_complete(phy, r);
870 		break;
871 
872 	default:
873 		break;
874 	}
875 }
876 
877 static int pn544_hci_i2c_acpi_request_resources(struct i2c_client *client)
878 {
879 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
880 	struct gpio_desc *gpiod_en, *gpiod_fw;
881 	struct device *dev = &client->dev;
882 
883 	/* Get EN GPIO from ACPI */
884 	gpiod_en = devm_gpiod_get_index(dev, PN544_GPIO_NAME_EN, 1,
885 					GPIOD_OUT_LOW);
886 	if (IS_ERR(gpiod_en)) {
887 		nfc_err(dev, "Unable to get EN GPIO\n");
888 		return -ENODEV;
889 	}
890 
891 	phy->gpio_en = desc_to_gpio(gpiod_en);
892 
893 	/* Get FW GPIO from ACPI */
894 	gpiod_fw = devm_gpiod_get_index(dev, PN544_GPIO_NAME_FW, 2,
895 					GPIOD_OUT_LOW);
896 	if (IS_ERR(gpiod_fw)) {
897 		nfc_err(dev, "Unable to get FW GPIO\n");
898 		return -ENODEV;
899 	}
900 
901 	phy->gpio_fw = desc_to_gpio(gpiod_fw);
902 
903 	return 0;
904 }
905 
906 static int pn544_hci_i2c_of_request_resources(struct i2c_client *client)
907 {
908 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
909 	struct device_node *pp;
910 	int ret;
911 
912 	pp = client->dev.of_node;
913 	if (!pp) {
914 		ret = -ENODEV;
915 		goto err_dt;
916 	}
917 
918 	/* Obtention of EN GPIO from device tree */
919 	ret = of_get_named_gpio(pp, "enable-gpios", 0);
920 	if (ret < 0) {
921 		if (ret != -EPROBE_DEFER)
922 			nfc_err(&client->dev,
923 				"Failed to get EN gpio, error: %d\n", ret);
924 		goto err_dt;
925 	}
926 	phy->gpio_en = ret;
927 
928 	/* Configuration of EN GPIO */
929 	ret = gpio_request(phy->gpio_en, PN544_GPIO_NAME_EN);
930 	if (ret) {
931 		nfc_err(&client->dev, "Fail EN pin\n");
932 		goto err_dt;
933 	}
934 	ret = gpio_direction_output(phy->gpio_en, 0);
935 	if (ret) {
936 		nfc_err(&client->dev, "Fail EN pin direction\n");
937 		goto err_gpio_en;
938 	}
939 
940 	/* Obtention of FW GPIO from device tree */
941 	ret = of_get_named_gpio(pp, "firmware-gpios", 0);
942 	if (ret < 0) {
943 		if (ret != -EPROBE_DEFER)
944 			nfc_err(&client->dev,
945 				"Failed to get FW gpio, error: %d\n", ret);
946 		goto err_gpio_en;
947 	}
948 	phy->gpio_fw = ret;
949 
950 	/* Configuration of FW GPIO */
951 	ret = gpio_request(phy->gpio_fw, PN544_GPIO_NAME_FW);
952 	if (ret) {
953 		nfc_err(&client->dev, "Fail FW pin\n");
954 		goto err_gpio_en;
955 	}
956 	ret = gpio_direction_output(phy->gpio_fw, 0);
957 	if (ret) {
958 		nfc_err(&client->dev, "Fail FW pin direction\n");
959 		goto err_gpio_fw;
960 	}
961 
962 	return 0;
963 
964 err_gpio_fw:
965 	gpio_free(phy->gpio_fw);
966 err_gpio_en:
967 	gpio_free(phy->gpio_en);
968 err_dt:
969 	return ret;
970 }
971 
972 static int pn544_hci_i2c_probe(struct i2c_client *client,
973 			       const struct i2c_device_id *id)
974 {
975 	struct pn544_i2c_phy *phy;
976 	struct pn544_nfc_platform_data *pdata;
977 	int r = 0;
978 
979 	dev_dbg(&client->dev, "%s\n", __func__);
980 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
981 
982 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
983 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
984 		return -ENODEV;
985 	}
986 
987 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
988 			   GFP_KERNEL);
989 	if (!phy)
990 		return -ENOMEM;
991 
992 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
993 	phy->fw_work_state = FW_WORK_STATE_IDLE;
994 
995 	phy->i2c_dev = client;
996 	i2c_set_clientdata(client, phy);
997 
998 	pdata = client->dev.platform_data;
999 
1000 	/* No platform data, using device tree. */
1001 	if (!pdata && client->dev.of_node) {
1002 		r = pn544_hci_i2c_of_request_resources(client);
1003 		if (r) {
1004 			nfc_err(&client->dev, "No DT data\n");
1005 			return r;
1006 		}
1007 	/* Using platform data. */
1008 	} else if (pdata) {
1009 
1010 		if (pdata->request_resources == NULL) {
1011 			nfc_err(&client->dev, "request_resources() missing\n");
1012 			return -EINVAL;
1013 		}
1014 
1015 		r = pdata->request_resources(client);
1016 		if (r) {
1017 			nfc_err(&client->dev,
1018 				"Cannot get platform resources\n");
1019 			return r;
1020 		}
1021 
1022 		phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
1023 		phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
1024 	/* Using ACPI */
1025 	} else if (ACPI_HANDLE(&client->dev)) {
1026 		r = pn544_hci_i2c_acpi_request_resources(client);
1027 		if (r) {
1028 			nfc_err(&client->dev,
1029 				"Cannot get ACPI data\n");
1030 			return r;
1031 		}
1032 	} else {
1033 		nfc_err(&client->dev, "No platform data\n");
1034 		return -EINVAL;
1035 	}
1036 
1037 	pn544_hci_i2c_platform_init(phy);
1038 
1039 	r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
1040 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1041 				 PN544_HCI_I2C_DRIVER_NAME, phy);
1042 	if (r < 0) {
1043 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
1044 		goto err_rti;
1045 	}
1046 
1047 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
1048 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
1049 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
1050 			    pn544_hci_i2c_fw_download, &phy->hdev);
1051 	if (r < 0)
1052 		goto err_hci;
1053 
1054 	return 0;
1055 
1056 err_hci:
1057 	free_irq(client->irq, phy);
1058 
1059 err_rti:
1060 	if (!pdata) {
1061 		gpio_free(phy->gpio_en);
1062 		gpio_free(phy->gpio_fw);
1063 	} else if (pdata->free_resources) {
1064 		pdata->free_resources();
1065 	}
1066 
1067 	return r;
1068 }
1069 
1070 static int pn544_hci_i2c_remove(struct i2c_client *client)
1071 {
1072 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
1073 	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
1074 
1075 	dev_dbg(&client->dev, "%s\n", __func__);
1076 
1077 	cancel_work_sync(&phy->fw_work);
1078 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
1079 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
1080 
1081 	pn544_hci_remove(phy->hdev);
1082 
1083 	if (phy->powered)
1084 		pn544_hci_i2c_disable(phy);
1085 
1086 	free_irq(client->irq, phy);
1087 
1088 	/* No platform data, GPIOs have been requested by this driver */
1089 	if (!pdata) {
1090 		gpio_free(phy->gpio_en);
1091 		gpio_free(phy->gpio_fw);
1092 	/* Using platform data */
1093 	} else if (pdata->free_resources) {
1094 		pdata->free_resources();
1095 	}
1096 
1097 	return 0;
1098 }
1099 
1100 static const struct of_device_id of_pn544_i2c_match[] = {
1101 	{ .compatible = "nxp,pn544-i2c", },
1102 	{},
1103 };
1104 MODULE_DEVICE_TABLE(of, of_pn544_i2c_match);
1105 
1106 static struct i2c_driver pn544_hci_i2c_driver = {
1107 	.driver = {
1108 		   .name = PN544_HCI_I2C_DRIVER_NAME,
1109 		   .of_match_table = of_match_ptr(of_pn544_i2c_match),
1110 		   .acpi_match_table = ACPI_PTR(pn544_hci_i2c_acpi_match),
1111 		  },
1112 	.probe = pn544_hci_i2c_probe,
1113 	.id_table = pn544_hci_i2c_id_table,
1114 	.remove = pn544_hci_i2c_remove,
1115 };
1116 
1117 module_i2c_driver(pn544_hci_i2c_driver);
1118 
1119 MODULE_LICENSE("GPL");
1120 MODULE_DESCRIPTION(DRIVER_DESC);
1121