xref: /linux/drivers/nfc/pn544/i2c.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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_irq;
170 	unsigned int gpio_fw;
171 	unsigned int en_polarity;
172 
173 	u8 hw_variant;
174 
175 	struct work_struct fw_work;
176 	int fw_work_state;
177 	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
178 	const struct firmware *fw;
179 	u32 fw_blob_dest_addr;
180 	size_t fw_blob_size;
181 	const u8 *fw_blob_data;
182 	size_t fw_written;
183 	size_t fw_size;
184 
185 	int fw_cmd_result;
186 
187 	int powered;
188 	int run_mode;
189 
190 	int hard_fault;		/*
191 				 * < 0 if hardware error occured (e.g. i2c err)
192 				 * and prevents normal operation.
193 				 */
194 };
195 
196 #define I2C_DUMP_SKB(info, skb)					\
197 do {								\
198 	pr_debug("%s:\n", info);				\
199 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
200 		       16, 1, (skb)->data, (skb)->len, 0);	\
201 } while (0)
202 
203 static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
204 {
205 	int polarity, retry, ret;
206 	char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
207 	int count = sizeof(rset_cmd);
208 
209 	nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");
210 
211 	/* Disable fw download */
212 	gpio_set_value_cansleep(phy->gpio_fw, 0);
213 
214 	for (polarity = 0; polarity < 2; polarity++) {
215 		phy->en_polarity = polarity;
216 		retry = 3;
217 		while (retry--) {
218 			/* power off */
219 			gpio_set_value_cansleep(phy->gpio_en,
220 						!phy->en_polarity);
221 			usleep_range(10000, 15000);
222 
223 			/* power on */
224 			gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
225 			usleep_range(10000, 15000);
226 
227 			/* send reset */
228 			dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
229 			ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
230 			if (ret == count) {
231 				nfc_info(&phy->i2c_dev->dev,
232 					 "nfc_en polarity : active %s\n",
233 					 (polarity == 0 ? "low" : "high"));
234 				goto out;
235 			}
236 		}
237 	}
238 
239 	nfc_err(&phy->i2c_dev->dev,
240 		"Could not detect nfc_en polarity, fallback to active high\n");
241 
242 out:
243 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
244 }
245 
246 static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
247 {
248 	gpio_set_value_cansleep(phy->gpio_fw,
249 				run_mode == PN544_FW_MODE ? 1 : 0);
250 	gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
251 	usleep_range(10000, 15000);
252 
253 	phy->run_mode = run_mode;
254 }
255 
256 static int pn544_hci_i2c_enable(void *phy_id)
257 {
258 	struct pn544_i2c_phy *phy = phy_id;
259 
260 	pr_info("%s\n", __func__);
261 
262 	pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);
263 
264 	phy->powered = 1;
265 
266 	return 0;
267 }
268 
269 static void pn544_hci_i2c_disable(void *phy_id)
270 {
271 	struct pn544_i2c_phy *phy = phy_id;
272 
273 	gpio_set_value_cansleep(phy->gpio_fw, 0);
274 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
275 	usleep_range(10000, 15000);
276 
277 	gpio_set_value_cansleep(phy->gpio_en, phy->en_polarity);
278 	usleep_range(10000, 15000);
279 
280 	gpio_set_value_cansleep(phy->gpio_en, !phy->en_polarity);
281 	usleep_range(10000, 15000);
282 
283 	phy->powered = 0;
284 }
285 
286 static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
287 {
288 	u16 crc;
289 	int len;
290 
291 	len = skb->len + 2;
292 	*skb_push(skb, 1) = len;
293 
294 	crc = crc_ccitt(0xffff, skb->data, skb->len);
295 	crc = ~crc;
296 	*skb_put(skb, 1) = crc & 0xff;
297 	*skb_put(skb, 1) = crc >> 8;
298 }
299 
300 static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
301 {
302 	skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
303 	skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
304 }
305 
306 /*
307  * Writing a frame must not return the number of written bytes.
308  * It must return either zero for success, or <0 for error.
309  * In addition, it must not alter the skb
310  */
311 static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
312 {
313 	int r;
314 	struct pn544_i2c_phy *phy = phy_id;
315 	struct i2c_client *client = phy->i2c_dev;
316 
317 	if (phy->hard_fault != 0)
318 		return phy->hard_fault;
319 
320 	usleep_range(3000, 6000);
321 
322 	pn544_hci_i2c_add_len_crc(skb);
323 
324 	I2C_DUMP_SKB("i2c frame written", skb);
325 
326 	r = i2c_master_send(client, skb->data, skb->len);
327 
328 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */
329 		usleep_range(6000, 10000);
330 		r = i2c_master_send(client, skb->data, skb->len);
331 	}
332 
333 	if (r >= 0) {
334 		if (r != skb->len)
335 			r = -EREMOTEIO;
336 		else
337 			r = 0;
338 	}
339 
340 	pn544_hci_i2c_remove_len_crc(skb);
341 
342 	return r;
343 }
344 
345 static int check_crc(u8 *buf, int buflen)
346 {
347 	int len;
348 	u16 crc;
349 
350 	len = buf[0] + 1;
351 	crc = crc_ccitt(0xffff, buf, len - 2);
352 	crc = ~crc;
353 
354 	if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
355 		pr_err("CRC error 0x%x != 0x%x 0x%x\n",
356 		       crc, buf[len - 1], buf[len - 2]);
357 		pr_info("%s: BAD CRC\n", __func__);
358 		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
359 			       16, 2, buf, buflen, false);
360 		return -EPERM;
361 	}
362 	return 0;
363 }
364 
365 /*
366  * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
367  * that i2c bus will be flushed and that next read will start on a new frame.
368  * returned skb contains only LLC header and payload.
369  * returns:
370  * -EREMOTEIO : i2c read error (fatal)
371  * -EBADMSG : frame was incorrect and discarded
372  * -ENOMEM : cannot allocate skb, frame dropped
373  */
374 static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
375 {
376 	int r;
377 	u8 len;
378 	u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
379 	struct i2c_client *client = phy->i2c_dev;
380 
381 	r = i2c_master_recv(client, &len, 1);
382 	if (r != 1) {
383 		nfc_err(&client->dev, "cannot read len byte\n");
384 		return -EREMOTEIO;
385 	}
386 
387 	if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
388 	    (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
389 		nfc_err(&client->dev, "invalid len byte\n");
390 		r = -EBADMSG;
391 		goto flush;
392 	}
393 
394 	*skb = alloc_skb(1 + len, GFP_KERNEL);
395 	if (*skb == NULL) {
396 		r = -ENOMEM;
397 		goto flush;
398 	}
399 
400 	*skb_put(*skb, 1) = len;
401 
402 	r = i2c_master_recv(client, skb_put(*skb, len), len);
403 	if (r != len) {
404 		kfree_skb(*skb);
405 		return -EREMOTEIO;
406 	}
407 
408 	I2C_DUMP_SKB("i2c frame read", *skb);
409 
410 	r = check_crc((*skb)->data, (*skb)->len);
411 	if (r != 0) {
412 		kfree_skb(*skb);
413 		r = -EBADMSG;
414 		goto flush;
415 	}
416 
417 	skb_pull(*skb, 1);
418 	skb_trim(*skb, (*skb)->len - 2);
419 
420 	usleep_range(3000, 6000);
421 
422 	return 0;
423 
424 flush:
425 	if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
426 		r = -EREMOTEIO;
427 
428 	usleep_range(3000, 6000);
429 
430 	return r;
431 }
432 
433 static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
434 {
435 	int r;
436 	struct pn544_i2c_fw_frame_response response;
437 	struct i2c_client *client = phy->i2c_dev;
438 
439 	r = i2c_master_recv(client, (char *) &response, sizeof(response));
440 	if (r != sizeof(response)) {
441 		nfc_err(&client->dev, "cannot read fw status\n");
442 		return -EIO;
443 	}
444 
445 	usleep_range(3000, 6000);
446 
447 	switch (response.status) {
448 	case 0:
449 		return 0;
450 	case PN544_FW_CMD_RESULT_CHUNK_OK:
451 		return response.status;
452 	case PN544_FW_CMD_RESULT_TIMEOUT:
453 		return -ETIMEDOUT;
454 	case PN544_FW_CMD_RESULT_BAD_CRC:
455 		return -ENODATA;
456 	case PN544_FW_CMD_RESULT_ACCESS_DENIED:
457 		return -EACCES;
458 	case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
459 		return -EPROTO;
460 	case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
461 		return -EINVAL;
462 	case PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND:
463 		return -ENOTSUPP;
464 	case PN544_FW_CMD_RESULT_INVALID_LENGTH:
465 		return -EBADMSG;
466 	case PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR:
467 		return -ENOKEY;
468 	case PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR:
469 		return -EINVAL;
470 	case PN544_FW_CMD_RESULT_MEMORY_ERROR:
471 		return -ENOMEM;
472 	case PN544_FW_CMD_RESULT_COMMAND_REJECTED:
473 		return -EACCES;
474 	case PN544_FW_CMD_RESULT_WRITE_FAILED:
475 	case PN544_FW_CMD_RESULT_CHUNK_ERROR:
476 		return -EIO;
477 	default:
478 		return -EIO;
479 	}
480 }
481 
482 /*
483  * Reads an shdlc frame from the chip. This is not as straightforward as it
484  * seems. There are cases where we could loose the frame start synchronization.
485  * The frame format is len-data-crc, and corruption can occur anywhere while
486  * transiting on i2c bus, such that we could read an invalid len.
487  * In order to recover synchronization with the next frame, we must be sure
488  * to read the real amount of data without using the len byte. We do this by
489  * assuming the following:
490  * - the chip will always present only one single complete frame on the bus
491  *   before triggering the interrupt
492  * - the chip will not present a new frame until we have completely read
493  *   the previous one (or until we have handled the interrupt).
494  * The tricky case is when we read a corrupted len that is less than the real
495  * len. We must detect this here in order to determine that we need to flush
496  * the bus. This is the reason why we check the crc here.
497  */
498 static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
499 {
500 	struct pn544_i2c_phy *phy = phy_id;
501 	struct i2c_client *client;
502 	struct sk_buff *skb = NULL;
503 	int r;
504 
505 	if (!phy || irq != phy->i2c_dev->irq) {
506 		WARN_ON_ONCE(1);
507 		return IRQ_NONE;
508 	}
509 
510 	client = phy->i2c_dev;
511 	dev_dbg(&client->dev, "IRQ\n");
512 
513 	if (phy->hard_fault != 0)
514 		return IRQ_HANDLED;
515 
516 	if (phy->run_mode == PN544_FW_MODE) {
517 		phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
518 		schedule_work(&phy->fw_work);
519 	} else {
520 		r = pn544_hci_i2c_read(phy, &skb);
521 		if (r == -EREMOTEIO) {
522 			phy->hard_fault = r;
523 
524 			nfc_hci_recv_frame(phy->hdev, NULL);
525 
526 			return IRQ_HANDLED;
527 		} else if ((r == -ENOMEM) || (r == -EBADMSG)) {
528 			return IRQ_HANDLED;
529 		}
530 
531 		nfc_hci_recv_frame(phy->hdev, skb);
532 	}
533 	return IRQ_HANDLED;
534 }
535 
536 static struct nfc_phy_ops i2c_phy_ops = {
537 	.write = pn544_hci_i2c_write,
538 	.enable = pn544_hci_i2c_enable,
539 	.disable = pn544_hci_i2c_disable,
540 };
541 
542 static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name,
543 					u8 hw_variant)
544 {
545 	struct pn544_i2c_phy *phy = phy_id;
546 
547 	pr_info("Starting Firmware Download (%s)\n", firmware_name);
548 
549 	strcpy(phy->firmware_name, firmware_name);
550 
551 	phy->hw_variant = hw_variant;
552 	phy->fw_work_state = FW_WORK_STATE_START;
553 
554 	schedule_work(&phy->fw_work);
555 
556 	return 0;
557 }
558 
559 static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
560 					   int result)
561 {
562 	pr_info("Firmware Download Complete, result=%d\n", result);
563 
564 	pn544_hci_i2c_disable(phy);
565 
566 	phy->fw_work_state = FW_WORK_STATE_IDLE;
567 
568 	if (phy->fw) {
569 		release_firmware(phy->fw);
570 		phy->fw = NULL;
571 	}
572 
573 	nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
574 }
575 
576 static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
577 				      const u8 *data, u16 datalen)
578 {
579 	u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
580 	struct pn544_i2c_fw_frame_write *framep;
581 	u16 params_len;
582 	int framelen;
583 	int r;
584 
585 	if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
586 		datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;
587 
588 	framep = (struct pn544_i2c_fw_frame_write *) frame;
589 
590 	params_len = sizeof(framep->be_dest_addr) +
591 		     sizeof(framep->be_datalen) + datalen;
592 	framelen = params_len + sizeof(framep->cmd) +
593 			     sizeof(framep->be_length);
594 
595 	framep->cmd = PN544_FW_CMD_WRITE;
596 
597 	put_unaligned_be16(params_len, &framep->be_length);
598 
599 	framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
600 	framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
601 	framep->be_dest_addr[2] = dest_addr & 0xff;
602 
603 	put_unaligned_be16(datalen, &framep->be_datalen);
604 
605 	memcpy(framep->data, data, datalen);
606 
607 	r = i2c_master_send(client, frame, framelen);
608 
609 	if (r == framelen)
610 		return datalen;
611 	else if (r < 0)
612 		return r;
613 	else
614 		return -EIO;
615 }
616 
617 static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
618 				      const u8 *data, u16 datalen)
619 {
620 	struct pn544_i2c_fw_frame_check frame;
621 	int r;
622 	u16 crc;
623 
624 	/* calculate local crc for the data we want to check */
625 	crc = crc_ccitt(0xffff, data, datalen);
626 
627 	frame.cmd = PN544_FW_CMD_CHECK;
628 
629 	put_unaligned_be16(sizeof(frame.be_start_addr) +
630 			   sizeof(frame.be_datalen) + sizeof(frame.be_crc),
631 			   &frame.be_length);
632 
633 	/* tell the chip the memory region to which our crc applies */
634 	frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
635 	frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
636 	frame.be_start_addr[2] = start_addr & 0xff;
637 
638 	put_unaligned_be16(datalen, &frame.be_datalen);
639 
640 	/*
641 	 * and give our local crc. Chip will calculate its own crc for the
642 	 * region and compare with ours.
643 	 */
644 	put_unaligned_be16(crc, &frame.be_crc);
645 
646 	r = i2c_master_send(client, (const char *) &frame, sizeof(frame));
647 
648 	if (r == sizeof(frame))
649 		return 0;
650 	else if (r < 0)
651 		return r;
652 	else
653 		return -EIO;
654 }
655 
656 static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
657 {
658 	int r;
659 
660 	r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
661 				       phy->fw_blob_dest_addr + phy->fw_written,
662 				       phy->fw_blob_data + phy->fw_written,
663 				       phy->fw_blob_size - phy->fw_written);
664 	if (r < 0)
665 		return r;
666 
667 	phy->fw_written += r;
668 	phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;
669 
670 	return 0;
671 }
672 
673 static int pn544_hci_i2c_fw_secure_write_frame_cmd(struct pn544_i2c_phy *phy,
674 					const u8 *data, u16 datalen)
675 {
676 	u8 buf[PN544_FW_I2C_MAX_PAYLOAD];
677 	struct pn544_i2c_fw_secure_frame *chunk;
678 	int chunklen;
679 	int r;
680 
681 	if (datalen > PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN)
682 		datalen = PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN;
683 
684 	chunk = (struct pn544_i2c_fw_secure_frame *) buf;
685 
686 	chunk->cmd = PN544_FW_CMD_SECURE_CHUNK_WRITE;
687 
688 	put_unaligned_be16(datalen, &chunk->be_datalen);
689 
690 	memcpy(chunk->data, data, datalen);
691 
692 	chunklen = sizeof(chunk->cmd) + sizeof(chunk->be_datalen) + datalen;
693 
694 	r = i2c_master_send(phy->i2c_dev, buf, chunklen);
695 
696 	if (r == chunklen)
697 		return datalen;
698 	else if (r < 0)
699 		return r;
700 	else
701 		return -EIO;
702 
703 }
704 
705 static int pn544_hci_i2c_fw_secure_write_frame(struct pn544_i2c_phy *phy)
706 {
707 	struct pn544_i2c_fw_secure_frame *framep;
708 	int r;
709 
710 	framep = (struct pn544_i2c_fw_secure_frame *) phy->fw_blob_data;
711 	if (phy->fw_written == 0)
712 		phy->fw_blob_size = get_unaligned_be16(&framep->be_datalen)
713 				+ PN544_FW_SECURE_FRAME_HEADER_LEN;
714 
715 	/* Only secure write command can be chunked*/
716 	if (phy->fw_blob_size > PN544_FW_I2C_MAX_PAYLOAD &&
717 			framep->cmd != PN544_FW_CMD_SECURE_WRITE)
718 		return -EINVAL;
719 
720 	/* The firmware also have other commands, we just send them directly */
721 	if (phy->fw_blob_size < PN544_FW_I2C_MAX_PAYLOAD) {
722 		r = i2c_master_send(phy->i2c_dev,
723 			(const char *) phy->fw_blob_data, phy->fw_blob_size);
724 
725 		if (r == phy->fw_blob_size)
726 			goto exit;
727 		else if (r < 0)
728 			return r;
729 		else
730 			return -EIO;
731 	}
732 
733 	r = pn544_hci_i2c_fw_secure_write_frame_cmd(phy,
734 				       phy->fw_blob_data + phy->fw_written,
735 				       phy->fw_blob_size - phy->fw_written);
736 	if (r < 0)
737 		return r;
738 
739 exit:
740 	phy->fw_written += r;
741 	phy->fw_work_state = FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER;
742 
743 	/* SW reset command will not trig any response from PN544 */
744 	if (framep->cmd == PN544_FW_CMD_RESET) {
745 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
746 		phy->fw_cmd_result = 0;
747 		schedule_work(&phy->fw_work);
748 	}
749 
750 	return 0;
751 }
752 
753 static void pn544_hci_i2c_fw_work(struct work_struct *work)
754 {
755 	struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
756 						fw_work);
757 	int r;
758 	struct pn544_i2c_fw_blob *blob;
759 	struct pn544_i2c_fw_secure_blob *secure_blob;
760 
761 	switch (phy->fw_work_state) {
762 	case FW_WORK_STATE_START:
763 		pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
764 
765 		r = request_firmware(&phy->fw, phy->firmware_name,
766 				     &phy->i2c_dev->dev);
767 		if (r < 0)
768 			goto exit_state_start;
769 
770 		phy->fw_written = 0;
771 
772 		switch (phy->hw_variant) {
773 		case PN544_HW_VARIANT_C2:
774 			blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
775 			phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
776 			phy->fw_blob_dest_addr = get_unaligned_be32(
777 							&blob->be_destaddr);
778 			phy->fw_blob_data = blob->data;
779 
780 			r = pn544_hci_i2c_fw_write_chunk(phy);
781 			break;
782 		case PN544_HW_VARIANT_C3:
783 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
784 								phy->fw->data;
785 			phy->fw_blob_data = secure_blob->data;
786 			phy->fw_size = phy->fw->size;
787 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
788 			break;
789 		default:
790 			r = -ENOTSUPP;
791 			break;
792 		}
793 
794 exit_state_start:
795 		if (r < 0)
796 			pn544_hci_i2c_fw_work_complete(phy, r);
797 		break;
798 
799 	case FW_WORK_STATE_WAIT_WRITE_ANSWER:
800 		r = phy->fw_cmd_result;
801 		if (r < 0)
802 			goto exit_state_wait_write_answer;
803 
804 		if (phy->fw_written == phy->fw_blob_size) {
805 			r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
806 						       phy->fw_blob_dest_addr,
807 						       phy->fw_blob_data,
808 						       phy->fw_blob_size);
809 			if (r < 0)
810 				goto exit_state_wait_write_answer;
811 			phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
812 			break;
813 		}
814 
815 		r = pn544_hci_i2c_fw_write_chunk(phy);
816 
817 exit_state_wait_write_answer:
818 		if (r < 0)
819 			pn544_hci_i2c_fw_work_complete(phy, r);
820 		break;
821 
822 	case FW_WORK_STATE_WAIT_CHECK_ANSWER:
823 		r = phy->fw_cmd_result;
824 		if (r < 0)
825 			goto exit_state_wait_check_answer;
826 
827 		blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
828 		       phy->fw_blob_size);
829 		phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
830 		if (phy->fw_blob_size != 0) {
831 			phy->fw_blob_dest_addr =
832 					get_unaligned_be32(&blob->be_destaddr);
833 			phy->fw_blob_data = blob->data;
834 
835 			phy->fw_written = 0;
836 			r = pn544_hci_i2c_fw_write_chunk(phy);
837 		}
838 
839 exit_state_wait_check_answer:
840 		if (r < 0 || phy->fw_blob_size == 0)
841 			pn544_hci_i2c_fw_work_complete(phy, r);
842 		break;
843 
844 	case FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER:
845 		r = phy->fw_cmd_result;
846 		if (r < 0)
847 			goto exit_state_wait_secure_write_answer;
848 
849 		if (r == PN544_FW_CMD_RESULT_CHUNK_OK) {
850 			r = pn544_hci_i2c_fw_secure_write_frame(phy);
851 			goto exit_state_wait_secure_write_answer;
852 		}
853 
854 		if (phy->fw_written == phy->fw_blob_size) {
855 			secure_blob = (struct pn544_i2c_fw_secure_blob *)
856 				(phy->fw_blob_data + phy->fw_blob_size);
857 			phy->fw_size -= phy->fw_blob_size +
858 				PN544_FW_SECURE_BLOB_HEADER_LEN;
859 			if (phy->fw_size >= PN544_FW_SECURE_BLOB_HEADER_LEN
860 					+ PN544_FW_SECURE_FRAME_HEADER_LEN) {
861 				phy->fw_blob_data = secure_blob->data;
862 
863 				phy->fw_written = 0;
864 				r = pn544_hci_i2c_fw_secure_write_frame(phy);
865 			}
866 		}
867 
868 exit_state_wait_secure_write_answer:
869 		if (r < 0 || phy->fw_size == 0)
870 			pn544_hci_i2c_fw_work_complete(phy, r);
871 		break;
872 
873 	default:
874 		break;
875 	}
876 }
877 
878 static int pn544_hci_i2c_acpi_request_resources(struct i2c_client *client)
879 {
880 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
881 	const struct acpi_device_id *id;
882 	struct gpio_desc *gpiod_en, *gpiod_irq, *gpiod_fw;
883 	struct device *dev;
884 	int ret;
885 
886 	if (!client)
887 		return -EINVAL;
888 
889 	dev = &client->dev;
890 
891 	/* Match the struct device against a given list of ACPI IDs */
892 	id = acpi_match_device(dev->driver->acpi_match_table, dev);
893 
894 	if (!id)
895 		return -ENODEV;
896 
897 	/* Get EN GPIO from ACPI */
898 	gpiod_en = devm_gpiod_get_index(dev, PN544_GPIO_NAME_EN, 1,
899 					GPIOD_OUT_LOW);
900 	if (IS_ERR(gpiod_en)) {
901 		nfc_err(dev, "Unable to get EN GPIO\n");
902 		return -ENODEV;
903 	}
904 
905 	phy->gpio_en = desc_to_gpio(gpiod_en);
906 
907 	/* Get FW GPIO from ACPI */
908 	gpiod_fw = devm_gpiod_get_index(dev, PN544_GPIO_NAME_FW, 2,
909 					GPIOD_OUT_LOW);
910 	if (IS_ERR(gpiod_fw)) {
911 		nfc_err(dev, "Unable to get FW GPIO\n");
912 		return -ENODEV;
913 	}
914 
915 	phy->gpio_fw = desc_to_gpio(gpiod_fw);
916 
917 	/* Get IRQ GPIO */
918 	gpiod_irq = devm_gpiod_get_index(dev, PN544_GPIO_NAME_IRQ, 0,
919 					 GPIOD_IN);
920 	if (IS_ERR(gpiod_irq)) {
921 		nfc_err(dev, "Unable to get IRQ GPIO\n");
922 		return -ENODEV;
923 	}
924 
925 	phy->gpio_irq = desc_to_gpio(gpiod_irq);
926 
927 	/* Map the pin to an IRQ */
928 	ret = gpiod_to_irq(gpiod_irq);
929 	if (ret < 0) {
930 		nfc_err(dev, "Fail pin IRQ mapping\n");
931 		return ret;
932 	}
933 
934 	nfc_info(dev, "GPIO resource, no:%d irq:%d\n",
935 		 desc_to_gpio(gpiod_irq), ret);
936 	client->irq = ret;
937 
938 	return 0;
939 }
940 
941 #ifdef CONFIG_OF
942 
943 static int pn544_hci_i2c_of_request_resources(struct i2c_client *client)
944 {
945 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
946 	struct device_node *pp;
947 	int ret;
948 
949 	pp = client->dev.of_node;
950 	if (!pp) {
951 		ret = -ENODEV;
952 		goto err_dt;
953 	}
954 
955 	/* Obtention of EN GPIO from device tree */
956 	ret = of_get_named_gpio(pp, "enable-gpios", 0);
957 	if (ret < 0) {
958 		if (ret != -EPROBE_DEFER)
959 			nfc_err(&client->dev,
960 				"Failed to get EN gpio, error: %d\n", ret);
961 		goto err_dt;
962 	}
963 	phy->gpio_en = ret;
964 
965 	/* Configuration of EN GPIO */
966 	ret = gpio_request(phy->gpio_en, PN544_GPIO_NAME_EN);
967 	if (ret) {
968 		nfc_err(&client->dev, "Fail EN pin\n");
969 		goto err_dt;
970 	}
971 	ret = gpio_direction_output(phy->gpio_en, 0);
972 	if (ret) {
973 		nfc_err(&client->dev, "Fail EN pin direction\n");
974 		goto err_gpio_en;
975 	}
976 
977 	/* Obtention of FW GPIO from device tree */
978 	ret = of_get_named_gpio(pp, "firmware-gpios", 0);
979 	if (ret < 0) {
980 		if (ret != -EPROBE_DEFER)
981 			nfc_err(&client->dev,
982 				"Failed to get FW gpio, error: %d\n", ret);
983 		goto err_gpio_en;
984 	}
985 	phy->gpio_fw = ret;
986 
987 	/* Configuration of FW GPIO */
988 	ret = gpio_request(phy->gpio_fw, PN544_GPIO_NAME_FW);
989 	if (ret) {
990 		nfc_err(&client->dev, "Fail FW pin\n");
991 		goto err_gpio_en;
992 	}
993 	ret = gpio_direction_output(phy->gpio_fw, 0);
994 	if (ret) {
995 		nfc_err(&client->dev, "Fail FW pin direction\n");
996 		goto err_gpio_fw;
997 	}
998 
999 	/* IRQ */
1000 	ret = irq_of_parse_and_map(pp, 0);
1001 	if (ret < 0) {
1002 		nfc_err(&client->dev,
1003 			"Unable to get irq, error: %d\n", ret);
1004 		goto err_gpio_fw;
1005 	}
1006 	client->irq = ret;
1007 
1008 	return 0;
1009 
1010 err_gpio_fw:
1011 	gpio_free(phy->gpio_fw);
1012 err_gpio_en:
1013 	gpio_free(phy->gpio_en);
1014 err_dt:
1015 	return ret;
1016 }
1017 
1018 #else
1019 
1020 static int pn544_hci_i2c_of_request_resources(struct i2c_client *client)
1021 {
1022 	return -ENODEV;
1023 }
1024 
1025 #endif
1026 
1027 static int pn544_hci_i2c_probe(struct i2c_client *client,
1028 			       const struct i2c_device_id *id)
1029 {
1030 	struct pn544_i2c_phy *phy;
1031 	struct pn544_nfc_platform_data *pdata;
1032 	int r = 0;
1033 
1034 	dev_dbg(&client->dev, "%s\n", __func__);
1035 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
1036 
1037 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1038 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
1039 		return -ENODEV;
1040 	}
1041 
1042 	phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
1043 			   GFP_KERNEL);
1044 	if (!phy)
1045 		return -ENOMEM;
1046 
1047 	INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
1048 	phy->fw_work_state = FW_WORK_STATE_IDLE;
1049 
1050 	phy->i2c_dev = client;
1051 	i2c_set_clientdata(client, phy);
1052 
1053 	pdata = client->dev.platform_data;
1054 
1055 	/* No platform data, using device tree. */
1056 	if (!pdata && client->dev.of_node) {
1057 		r = pn544_hci_i2c_of_request_resources(client);
1058 		if (r) {
1059 			nfc_err(&client->dev, "No DT data\n");
1060 			return r;
1061 		}
1062 	/* Using platform data. */
1063 	} else if (pdata) {
1064 
1065 		if (pdata->request_resources == NULL) {
1066 			nfc_err(&client->dev, "request_resources() missing\n");
1067 			return -EINVAL;
1068 		}
1069 
1070 		r = pdata->request_resources(client);
1071 		if (r) {
1072 			nfc_err(&client->dev,
1073 				"Cannot get platform resources\n");
1074 			return r;
1075 		}
1076 
1077 		phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
1078 		phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
1079 		phy->gpio_irq = pdata->get_gpio(NFC_GPIO_IRQ);
1080 	/* Using ACPI */
1081 	} else if (ACPI_HANDLE(&client->dev)) {
1082 		r = pn544_hci_i2c_acpi_request_resources(client);
1083 		if (r) {
1084 			nfc_err(&client->dev,
1085 				"Cannot get ACPI data\n");
1086 			return r;
1087 		}
1088 	} else {
1089 		nfc_err(&client->dev, "No platform data\n");
1090 		return -EINVAL;
1091 	}
1092 
1093 	pn544_hci_i2c_platform_init(phy);
1094 
1095 	r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
1096 				 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1097 				 PN544_HCI_I2C_DRIVER_NAME, phy);
1098 	if (r < 0) {
1099 		nfc_err(&client->dev, "Unable to register IRQ handler\n");
1100 		goto err_rti;
1101 	}
1102 
1103 	r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
1104 			    PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
1105 			    PN544_HCI_I2C_LLC_MAX_PAYLOAD,
1106 			    pn544_hci_i2c_fw_download, &phy->hdev);
1107 	if (r < 0)
1108 		goto err_hci;
1109 
1110 	return 0;
1111 
1112 err_hci:
1113 	free_irq(client->irq, phy);
1114 
1115 err_rti:
1116 	if (!pdata) {
1117 		gpio_free(phy->gpio_en);
1118 		gpio_free(phy->gpio_fw);
1119 	} else if (pdata->free_resources) {
1120 		pdata->free_resources();
1121 	}
1122 
1123 	return r;
1124 }
1125 
1126 static int pn544_hci_i2c_remove(struct i2c_client *client)
1127 {
1128 	struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
1129 	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;
1130 
1131 	dev_dbg(&client->dev, "%s\n", __func__);
1132 
1133 	cancel_work_sync(&phy->fw_work);
1134 	if (phy->fw_work_state != FW_WORK_STATE_IDLE)
1135 		pn544_hci_i2c_fw_work_complete(phy, -ENODEV);
1136 
1137 	pn544_hci_remove(phy->hdev);
1138 
1139 	if (phy->powered)
1140 		pn544_hci_i2c_disable(phy);
1141 
1142 	free_irq(client->irq, phy);
1143 
1144 	/* No platform data, GPIOs have been requested by this driver */
1145 	if (!pdata) {
1146 		gpio_free(phy->gpio_en);
1147 		gpio_free(phy->gpio_fw);
1148 	/* Using platform data */
1149 	} else if (pdata->free_resources) {
1150 		pdata->free_resources();
1151 	}
1152 
1153 	return 0;
1154 }
1155 
1156 static const struct of_device_id of_pn544_i2c_match[] = {
1157 	{ .compatible = "nxp,pn544-i2c", },
1158 	{},
1159 };
1160 MODULE_DEVICE_TABLE(of, of_pn544_i2c_match);
1161 
1162 static struct i2c_driver pn544_hci_i2c_driver = {
1163 	.driver = {
1164 		   .name = PN544_HCI_I2C_DRIVER_NAME,
1165 		   .owner  = THIS_MODULE,
1166 		   .of_match_table = of_match_ptr(of_pn544_i2c_match),
1167 		   .acpi_match_table = ACPI_PTR(pn544_hci_i2c_acpi_match),
1168 		  },
1169 	.probe = pn544_hci_i2c_probe,
1170 	.id_table = pn544_hci_i2c_id_table,
1171 	.remove = pn544_hci_i2c_remove,
1172 };
1173 
1174 module_i2c_driver(pn544_hci_i2c_driver);
1175 
1176 MODULE_LICENSE("GPL");
1177 MODULE_DESCRIPTION(DRIVER_DESC);
1178