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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * --------------------------------------------------------------------
4 * Driver for ST NFC Transceiver ST95HF
5 * --------------------------------------------------------------------
6 * Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved.
7 */
8
9#include <linux/err.h>
10#include <linux/gpio.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/module.h>
15#include <linux/netdevice.h>
16#include <linux/nfc.h>
17#include <linux/of_gpio.h>
18#include <linux/of.h>
19#include <linux/of_irq.h>
20#include <linux/property.h>
21#include <linux/regulator/consumer.h>
22#include <linux/wait.h>
23#include <net/nfc/digital.h>
24#include <net/nfc/nfc.h>
25
26#include "spi.h"
27
28/* supported protocols */
29#define ST95HF_SUPPORTED_PROT (NFC_PROTO_ISO14443_MASK | \
30 NFC_PROTO_ISO14443_B_MASK | \
31 NFC_PROTO_ISO15693_MASK)
32/* driver capabilities */
33#define ST95HF_CAPABILITIES NFC_DIGITAL_DRV_CAPS_IN_CRC
34
35/* Command Send Interface */
36/* ST95HF_COMMAND_SEND CMD Ids */
37#define ECHO_CMD 0x55
38#define WRITE_REGISTER_CMD 0x9
39#define PROTOCOL_SELECT_CMD 0x2
40#define SEND_RECEIVE_CMD 0x4
41
42/* Select protocol codes */
43#define ISO15693_PROTOCOL_CODE 0x1
44#define ISO14443A_PROTOCOL_CODE 0x2
45#define ISO14443B_PROTOCOL_CODE 0x3
46
47/*
48 * head room len is 3
49 * 1 byte for control byte
50 * 1 byte for cmd
51 * 1 byte for size
52 */
53#define ST95HF_HEADROOM_LEN 3
54
55/*
56 * tailroom is 1 for ISO14443A
57 * and 0 for ISO14443B/ISO15693,
58 * hence the max value 1 should be
59 * taken.
60 */
61#define ST95HF_TAILROOM_LEN 1
62
63/* Command Response interface */
64#define MAX_RESPONSE_BUFFER_SIZE 280
65#define ECHORESPONSE 0x55
66#define ST95HF_ERR_MASK 0xF
67#define ST95HF_TIMEOUT_ERROR 0x87
68#define ST95HF_NFCA_CRC_ERR_MASK 0x20
69#define ST95HF_NFCB_CRC_ERR_MASK 0x01
70
71/* ST95HF transmission flag values */
72#define TRFLAG_NFCA_SHORT_FRAME 0x07
73#define TRFLAG_NFCA_STD_FRAME 0x08
74#define TRFLAG_NFCA_STD_FRAME_CRC 0x28
75
76/* Misc defs */
77#define HIGH 1
78#define LOW 0
79#define ISO14443A_RATS_REQ 0xE0
80#define RATS_TB1_PRESENT_MASK 0x20
81#define RATS_TA1_PRESENT_MASK 0x10
82#define TB1_FWI_MASK 0xF0
83#define WTX_REQ_FROM_TAG 0xF2
84
85#define MAX_CMD_LEN 0x7
86
87#define MAX_CMD_PARAMS 4
88struct cmd {
89 int cmd_len;
90 unsigned char cmd_id;
91 unsigned char no_cmd_params;
92 unsigned char cmd_params[MAX_CMD_PARAMS];
93 enum req_type req;
94};
95
96struct param_list {
97 int param_offset;
98 int new_param_val;
99};
100
101/*
102 * List of top-level cmds to be used internally by the driver.
103 * All these commands are build on top of ST95HF basic commands
104 * such as SEND_RECEIVE_CMD, PROTOCOL_SELECT_CMD, etc.
105 * These top level cmds are used internally while implementing various ops of
106 * digital layer/driver probe or extending the digital framework layer for
107 * features that are not yet implemented there, for example, WTX cmd handling.
108 */
109enum st95hf_cmd_list {
110 CMD_ECHO,
111 CMD_ISO14443A_CONFIG,
112 CMD_ISO14443A_DEMOGAIN,
113 CMD_ISO14443B_DEMOGAIN,
114 CMD_ISO14443A_PROTOCOL_SELECT,
115 CMD_ISO14443B_PROTOCOL_SELECT,
116 CMD_WTX_RESPONSE,
117 CMD_FIELD_OFF,
118 CMD_ISO15693_PROTOCOL_SELECT,
119};
120
121static const struct cmd cmd_array[] = {
122 [CMD_ECHO] = {
123 .cmd_len = 0x2,
124 .cmd_id = ECHO_CMD,
125 .no_cmd_params = 0,
126 .req = SYNC,
127 },
128 [CMD_ISO14443A_CONFIG] = {
129 .cmd_len = 0x7,
130 .cmd_id = WRITE_REGISTER_CMD,
131 .no_cmd_params = 0x4,
132 .cmd_params = {0x3A, 0x00, 0x5A, 0x04},
133 .req = SYNC,
134 },
135 [CMD_ISO14443A_DEMOGAIN] = {
136 .cmd_len = 0x7,
137 .cmd_id = WRITE_REGISTER_CMD,
138 .no_cmd_params = 0x4,
139 .cmd_params = {0x68, 0x01, 0x01, 0xDF},
140 .req = SYNC,
141 },
142 [CMD_ISO14443B_DEMOGAIN] = {
143 .cmd_len = 0x7,
144 .cmd_id = WRITE_REGISTER_CMD,
145 .no_cmd_params = 0x4,
146 .cmd_params = {0x68, 0x01, 0x01, 0x51},
147 .req = SYNC,
148 },
149 [CMD_ISO14443A_PROTOCOL_SELECT] = {
150 .cmd_len = 0x7,
151 .cmd_id = PROTOCOL_SELECT_CMD,
152 .no_cmd_params = 0x4,
153 .cmd_params = {ISO14443A_PROTOCOL_CODE, 0x00, 0x01, 0xA0},
154 .req = SYNC,
155 },
156 [CMD_ISO14443B_PROTOCOL_SELECT] = {
157 .cmd_len = 0x7,
158 .cmd_id = PROTOCOL_SELECT_CMD,
159 .no_cmd_params = 0x4,
160 .cmd_params = {ISO14443B_PROTOCOL_CODE, 0x01, 0x03, 0xFF},
161 .req = SYNC,
162 },
163 [CMD_WTX_RESPONSE] = {
164 .cmd_len = 0x6,
165 .cmd_id = SEND_RECEIVE_CMD,
166 .no_cmd_params = 0x3,
167 .cmd_params = {0xF2, 0x00, TRFLAG_NFCA_STD_FRAME_CRC},
168 .req = ASYNC,
169 },
170 [CMD_FIELD_OFF] = {
171 .cmd_len = 0x5,
172 .cmd_id = PROTOCOL_SELECT_CMD,
173 .no_cmd_params = 0x2,
174 .cmd_params = {0x0, 0x0},
175 .req = SYNC,
176 },
177 [CMD_ISO15693_PROTOCOL_SELECT] = {
178 .cmd_len = 0x5,
179 .cmd_id = PROTOCOL_SELECT_CMD,
180 .no_cmd_params = 0x2,
181 .cmd_params = {ISO15693_PROTOCOL_CODE, 0x0D},
182 .req = SYNC,
183 },
184};
185
186/* st95_digital_cmd_complete_arg stores client context */
187struct st95_digital_cmd_complete_arg {
188 struct sk_buff *skb_resp;
189 nfc_digital_cmd_complete_t complete_cb;
190 void *cb_usrarg;
191 bool rats;
192};
193
194/*
195 * structure containing ST95HF driver specific data.
196 * @spicontext: structure containing information required
197 * for spi communication between st95hf and host.
198 * @ddev: nfc digital device object.
199 * @nfcdev: nfc device object.
200 * @enable_gpio: gpio used to enable st95hf transceiver.
201 * @complete_cb_arg: structure to store various context information
202 * that is passed from nfc requesting thread to the threaded ISR.
203 * @st95hf_supply: regulator "consumer" for NFC device.
204 * @sendrcv_trflag: last byte of frame send by sendrecv command
205 * of st95hf. This byte contains transmission flag info.
206 * @exchange_lock: semaphore used for signaling the st95hf_remove
207 * function that the last outstanding async nfc request is finished.
208 * @rm_lock: mutex for ensuring safe access of nfc digital object
209 * from threaded ISR. Usage of this mutex avoids any race between
210 * deletion of the object from st95hf_remove() and its access from
211 * the threaded ISR.
212 * @nfcdev_free: flag to have the state of nfc device object.
213 * [alive | died]
214 * @current_protocol: current nfc protocol.
215 * @current_rf_tech: current rf technology.
216 * @fwi: frame waiting index, received in reply of RATS according to
217 * digital protocol.
218 */
219struct st95hf_context {
220 struct st95hf_spi_context spicontext;
221 struct nfc_digital_dev *ddev;
222 struct nfc_dev *nfcdev;
223 unsigned int enable_gpio;
224 struct st95_digital_cmd_complete_arg complete_cb_arg;
225 struct regulator *st95hf_supply;
226 unsigned char sendrcv_trflag;
227 struct semaphore exchange_lock;
228 struct mutex rm_lock;
229 bool nfcdev_free;
230 u8 current_protocol;
231 u8 current_rf_tech;
232 int fwi;
233};
234
235/*
236 * st95hf_send_recv_cmd() is for sending commands to ST95HF
237 * that are described in the cmd_array[]. It can optionally
238 * receive the response if the cmd request is of type
239 * SYNC. For that to happen caller must pass true to recv_res.
240 * For ASYNC request, recv_res is ignored and the
241 * function will never try to receive the response on behalf
242 * of the caller.
243 */
244static int st95hf_send_recv_cmd(struct st95hf_context *st95context,
245 enum st95hf_cmd_list cmd,
246 int no_modif,
247 struct param_list *list_array,
248 bool recv_res)
249{
250 unsigned char spi_cmd_buffer[MAX_CMD_LEN];
251 int i, ret;
252 struct device *dev = &st95context->spicontext.spidev->dev;
253
254 if (cmd_array[cmd].cmd_len > MAX_CMD_LEN)
255 return -EINVAL;
256 if (cmd_array[cmd].no_cmd_params < no_modif)
257 return -EINVAL;
258 if (no_modif && !list_array)
259 return -EINVAL;
260
261 spi_cmd_buffer[0] = ST95HF_COMMAND_SEND;
262 spi_cmd_buffer[1] = cmd_array[cmd].cmd_id;
263 spi_cmd_buffer[2] = cmd_array[cmd].no_cmd_params;
264
265 memcpy(&spi_cmd_buffer[3], cmd_array[cmd].cmd_params,
266 spi_cmd_buffer[2]);
267
268 for (i = 0; i < no_modif; i++) {
269 if (list_array[i].param_offset >= cmd_array[cmd].no_cmd_params)
270 return -EINVAL;
271 spi_cmd_buffer[3 + list_array[i].param_offset] =
272 list_array[i].new_param_val;
273 }
274
275 ret = st95hf_spi_send(&st95context->spicontext,
276 spi_cmd_buffer,
277 cmd_array[cmd].cmd_len,
278 cmd_array[cmd].req);
279 if (ret) {
280 dev_err(dev, "st95hf_spi_send failed with error %d\n", ret);
281 return ret;
282 }
283
284 if (cmd_array[cmd].req == SYNC && recv_res) {
285 unsigned char st95hf_response_arr[2];
286
287 ret = st95hf_spi_recv_response(&st95context->spicontext,
288 st95hf_response_arr);
289 if (ret < 0) {
290 dev_err(dev, "spi error from st95hf_spi_recv_response(), err = 0x%x\n",
291 ret);
292 return ret;
293 }
294
295 if (st95hf_response_arr[0]) {
296 dev_err(dev, "st95hf error from st95hf_spi_recv_response(), err = 0x%x\n",
297 st95hf_response_arr[0]);
298 return -EIO;
299 }
300 }
301
302 return 0;
303}
304
305static int st95hf_echo_command(struct st95hf_context *st95context)
306{
307 int result = 0;
308 unsigned char echo_response;
309
310 result = st95hf_send_recv_cmd(st95context, CMD_ECHO, 0, NULL, false);
311 if (result)
312 return result;
313
314 /* If control reached here, response can be taken */
315 result = st95hf_spi_recv_echo_res(&st95context->spicontext,
316 &echo_response);
317 if (result) {
318 dev_err(&st95context->spicontext.spidev->dev,
319 "err: echo response receive error = 0x%x\n", result);
320 return result;
321 }
322
323 if (echo_response == ECHORESPONSE)
324 return 0;
325
326 dev_err(&st95context->spicontext.spidev->dev, "err: echo res is 0x%x\n",
327 echo_response);
328
329 return -EIO;
330}
331
332static int secondary_configuration_type4a(struct st95hf_context *stcontext)
333{
334 int result = 0;
335 struct device *dev = &stcontext->nfcdev->dev;
336
337 /* 14443A config setting after select protocol */
338 result = st95hf_send_recv_cmd(stcontext,
339 CMD_ISO14443A_CONFIG,
340 0,
341 NULL,
342 true);
343 if (result) {
344 dev_err(dev, "type a config cmd, err = 0x%x\n", result);
345 return result;
346 }
347
348 /* 14443A demo gain setting */
349 result = st95hf_send_recv_cmd(stcontext,
350 CMD_ISO14443A_DEMOGAIN,
351 0,
352 NULL,
353 true);
354 if (result)
355 dev_err(dev, "type a demogain cmd, err = 0x%x\n", result);
356
357 return result;
358}
359
360static int secondary_configuration_type4b(struct st95hf_context *stcontext)
361{
362 int result = 0;
363 struct device *dev = &stcontext->nfcdev->dev;
364
365 result = st95hf_send_recv_cmd(stcontext,
366 CMD_ISO14443B_DEMOGAIN,
367 0,
368 NULL,
369 true);
370 if (result)
371 dev_err(dev, "type b demogain cmd, err = 0x%x\n", result);
372
373 return result;
374}
375
376static int st95hf_select_protocol(struct st95hf_context *stcontext, int type)
377{
378 int result = 0;
379 struct device *dev;
380
381 dev = &stcontext->nfcdev->dev;
382
383 switch (type) {
384 case NFC_DIGITAL_RF_TECH_106A:
385 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106A;
386 result = st95hf_send_recv_cmd(stcontext,
387 CMD_ISO14443A_PROTOCOL_SELECT,
388 0,
389 NULL,
390 true);
391 if (result) {
392 dev_err(dev, "protocol sel, err = 0x%x\n",
393 result);
394 return result;
395 }
396
397 /* secondary config. for 14443Type 4A after protocol select */
398 result = secondary_configuration_type4a(stcontext);
399 if (result) {
400 dev_err(dev, "type a secondary config, err = 0x%x\n",
401 result);
402 return result;
403 }
404 break;
405 case NFC_DIGITAL_RF_TECH_106B:
406 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106B;
407 result = st95hf_send_recv_cmd(stcontext,
408 CMD_ISO14443B_PROTOCOL_SELECT,
409 0,
410 NULL,
411 true);
412 if (result) {
413 dev_err(dev, "protocol sel send, err = 0x%x\n",
414 result);
415 return result;
416 }
417
418 /*
419 * delay of 5-6 ms is required after select protocol
420 * command in case of ISO14443 Type B
421 */
422 usleep_range(50000, 60000);
423
424 /* secondary config. for 14443Type 4B after protocol select */
425 result = secondary_configuration_type4b(stcontext);
426 if (result) {
427 dev_err(dev, "type b secondary config, err = 0x%x\n",
428 result);
429 return result;
430 }
431 break;
432 case NFC_DIGITAL_RF_TECH_ISO15693:
433 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_ISO15693;
434 result = st95hf_send_recv_cmd(stcontext,
435 CMD_ISO15693_PROTOCOL_SELECT,
436 0,
437 NULL,
438 true);
439 if (result) {
440 dev_err(dev, "protocol sel send, err = 0x%x\n",
441 result);
442 return result;
443 }
444 break;
445 default:
446 return -EINVAL;
447 }
448
449 return 0;
450}
451
452static void st95hf_send_st95enable_negativepulse(struct st95hf_context *st95con)
453{
454 /* First make irq_in pin high */
455 gpio_set_value(st95con->enable_gpio, HIGH);
456
457 /* wait for 1 milisecond */
458 usleep_range(1000, 2000);
459
460 /* Make irq_in pin low */
461 gpio_set_value(st95con->enable_gpio, LOW);
462
463 /* wait for minimum interrupt pulse to make st95 active */
464 usleep_range(1000, 2000);
465
466 /* At end make it high */
467 gpio_set_value(st95con->enable_gpio, HIGH);
468}
469
470/*
471 * Send a reset sequence over SPI bus (Reset command + wait 3ms +
472 * negative pulse on st95hf enable gpio
473 */
474static int st95hf_send_spi_reset_sequence(struct st95hf_context *st95context)
475{
476 int result = 0;
477 unsigned char reset_cmd = ST95HF_COMMAND_RESET;
478
479 result = st95hf_spi_send(&st95context->spicontext,
480 &reset_cmd,
481 ST95HF_RESET_CMD_LEN,
482 ASYNC);
483 if (result) {
484 dev_err(&st95context->spicontext.spidev->dev,
485 "spi reset sequence cmd error = %d", result);
486 return result;
487 }
488
489 /* wait for 3 milisecond to complete the controller reset process */
490 usleep_range(3000, 4000);
491
492 /* send negative pulse to make st95hf active */
493 st95hf_send_st95enable_negativepulse(st95context);
494
495 /* wait for 10 milisecond : HFO setup time */
496 usleep_range(10000, 20000);
497
498 return result;
499}
500
501static int st95hf_por_sequence(struct st95hf_context *st95context)
502{
503 int nth_attempt = 1;
504 int result;
505
506 st95hf_send_st95enable_negativepulse(st95context);
507
508 usleep_range(5000, 6000);
509 do {
510 /* send an ECHO command and checks ST95HF response */
511 result = st95hf_echo_command(st95context);
512
513 dev_dbg(&st95context->spicontext.spidev->dev,
514 "response from echo function = 0x%x, attempt = %d\n",
515 result, nth_attempt);
516
517 if (!result)
518 return 0;
519
520 /* send an pulse on IRQ in case of the chip is on sleep state */
521 if (nth_attempt == 2)
522 st95hf_send_st95enable_negativepulse(st95context);
523 else
524 st95hf_send_spi_reset_sequence(st95context);
525
526 /* delay of 50 milisecond */
527 usleep_range(50000, 51000);
528 } while (nth_attempt++ < 3);
529
530 return -ETIMEDOUT;
531}
532
533static int iso14443_config_fdt(struct st95hf_context *st95context, int wtxm)
534{
535 int result = 0;
536 struct device *dev = &st95context->spicontext.spidev->dev;
537 struct nfc_digital_dev *nfcddev = st95context->ddev;
538 unsigned char pp_typeb;
539 struct param_list new_params[2];
540
541 pp_typeb = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[2];
542
543 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 &&
544 st95context->fwi < 4)
545 st95context->fwi = 4;
546
547 new_params[0].param_offset = 2;
548 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
549 new_params[0].new_param_val = st95context->fwi;
550 else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
551 new_params[0].new_param_val = pp_typeb;
552
553 new_params[1].param_offset = 3;
554 new_params[1].new_param_val = wtxm;
555
556 switch (nfcddev->curr_protocol) {
557 case NFC_PROTO_ISO14443:
558 result = st95hf_send_recv_cmd(st95context,
559 CMD_ISO14443A_PROTOCOL_SELECT,
560 2,
561 new_params,
562 true);
563 if (result) {
564 dev_err(dev, "WTX type a sel proto, err = 0x%x\n",
565 result);
566 return result;
567 }
568
569 /* secondary config. for 14443Type 4A after protocol select */
570 result = secondary_configuration_type4a(st95context);
571 if (result) {
572 dev_err(dev, "WTX type a second. config, err = 0x%x\n",
573 result);
574 return result;
575 }
576 break;
577 case NFC_PROTO_ISO14443_B:
578 result = st95hf_send_recv_cmd(st95context,
579 CMD_ISO14443B_PROTOCOL_SELECT,
580 2,
581 new_params,
582 true);
583 if (result) {
584 dev_err(dev, "WTX type b sel proto, err = 0x%x\n",
585 result);
586 return result;
587 }
588
589 /* secondary config. for 14443Type 4B after protocol select */
590 result = secondary_configuration_type4b(st95context);
591 if (result) {
592 dev_err(dev, "WTX type b second. config, err = 0x%x\n",
593 result);
594 return result;
595 }
596 break;
597 default:
598 return -EINVAL;
599 }
600
601 return 0;
602}
603
604static int st95hf_handle_wtx(struct st95hf_context *stcontext,
605 bool new_wtx,
606 int wtx_val)
607{
608 int result = 0;
609 unsigned char val_mm = 0;
610 struct param_list new_params[1];
611 struct nfc_digital_dev *nfcddev = stcontext->ddev;
612 struct device *dev = &stcontext->nfcdev->dev;
613
614 if (new_wtx) {
615 result = iso14443_config_fdt(stcontext, wtx_val & 0x3f);
616 if (result) {
617 dev_err(dev, "Config. setting error on WTX req, err = 0x%x\n",
618 result);
619 return result;
620 }
621
622 /* Send response of wtx with ASYNC as no response expected */
623 new_params[0].param_offset = 1;
624 new_params[0].new_param_val = wtx_val;
625
626 result = st95hf_send_recv_cmd(stcontext,
627 CMD_WTX_RESPONSE,
628 1,
629 new_params,
630 false);
631 if (result)
632 dev_err(dev, "WTX response send, err = 0x%x\n", result);
633 return result;
634 }
635
636 /* if no new wtx, cofigure with default values */
637 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
638 val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
639 else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
640 val_mm = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[3];
641
642 result = iso14443_config_fdt(stcontext, val_mm);
643 if (result)
644 dev_err(dev, "Default config. setting error after WTX processing, err = 0x%x\n",
645 result);
646
647 return result;
648}
649
650static int st95hf_error_handling(struct st95hf_context *stcontext,
651 struct sk_buff *skb_resp,
652 int res_len)
653{
654 int result = 0;
655 unsigned char error_byte;
656 struct device *dev = &stcontext->nfcdev->dev;
657
658 /* First check ST95HF specific error */
659 if (skb_resp->data[0] & ST95HF_ERR_MASK) {
660 if (skb_resp->data[0] == ST95HF_TIMEOUT_ERROR)
661 result = -ETIMEDOUT;
662 else
663 result = -EIO;
664 return result;
665 }
666
667 /* Check for CRC err only if CRC is present in the tag response */
668 switch (stcontext->current_rf_tech) {
669 case NFC_DIGITAL_RF_TECH_106A:
670 if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC) {
671 error_byte = skb_resp->data[res_len - 3];
672 if (error_byte & ST95HF_NFCA_CRC_ERR_MASK) {
673 /* CRC error occurred */
674 dev_err(dev, "CRC error, byte received = 0x%x\n",
675 error_byte);
676 result = -EIO;
677 }
678 }
679 break;
680 case NFC_DIGITAL_RF_TECH_106B:
681 case NFC_DIGITAL_RF_TECH_ISO15693:
682 error_byte = skb_resp->data[res_len - 1];
683 if (error_byte & ST95HF_NFCB_CRC_ERR_MASK) {
684 /* CRC error occurred */
685 dev_err(dev, "CRC error, byte received = 0x%x\n",
686 error_byte);
687 result = -EIO;
688 }
689 break;
690 }
691
692 return result;
693}
694
695static int st95hf_response_handler(struct st95hf_context *stcontext,
696 struct sk_buff *skb_resp,
697 int res_len)
698{
699 int result = 0;
700 int skb_len;
701 unsigned char val_mm;
702 struct nfc_digital_dev *nfcddev = stcontext->ddev;
703 struct device *dev = &stcontext->nfcdev->dev;
704 struct st95_digital_cmd_complete_arg *cb_arg;
705
706 cb_arg = &stcontext->complete_cb_arg;
707
708 /* Process the response */
709 skb_put(skb_resp, res_len);
710
711 /* Remove st95 header */
712 skb_pull(skb_resp, 2);
713
714 skb_len = skb_resp->len;
715
716 /* check if it is case of RATS request reply & FWI is present */
717 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 && cb_arg->rats &&
718 (skb_resp->data[1] & RATS_TB1_PRESENT_MASK)) {
719 if (skb_resp->data[1] & RATS_TA1_PRESENT_MASK)
720 stcontext->fwi =
721 (skb_resp->data[3] & TB1_FWI_MASK) >> 4;
722 else
723 stcontext->fwi =
724 (skb_resp->data[2] & TB1_FWI_MASK) >> 4;
725
726 val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
727
728 result = iso14443_config_fdt(stcontext, val_mm);
729 if (result) {
730 dev_err(dev, "error in config_fdt to handle fwi of ATS, error=%d\n",
731 result);
732 return result;
733 }
734 }
735 cb_arg->rats = false;
736
737 /* Remove CRC bytes only if received frames data has an eod (CRC) */
738 switch (stcontext->current_rf_tech) {
739 case NFC_DIGITAL_RF_TECH_106A:
740 if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC)
741 skb_trim(skb_resp, (skb_len - 5));
742 else
743 skb_trim(skb_resp, (skb_len - 3));
744 break;
745 case NFC_DIGITAL_RF_TECH_106B:
746 case NFC_DIGITAL_RF_TECH_ISO15693:
747 skb_trim(skb_resp, (skb_len - 3));
748 break;
749 }
750
751 return result;
752}
753
754static irqreturn_t st95hf_irq_handler(int irq, void *st95hfcontext)
755{
756 struct st95hf_context *stcontext =
757 (struct st95hf_context *)st95hfcontext;
758
759 if (stcontext->spicontext.req_issync) {
760 complete(&stcontext->spicontext.done);
761 stcontext->spicontext.req_issync = false;
762 return IRQ_HANDLED;
763 }
764
765 return IRQ_WAKE_THREAD;
766}
767
768static irqreturn_t st95hf_irq_thread_handler(int irq, void *st95hfcontext)
769{
770 int result = 0;
771 int res_len;
772 static bool wtx;
773 struct device *spidevice;
774 struct sk_buff *skb_resp;
775 struct st95hf_context *stcontext =
776 (struct st95hf_context *)st95hfcontext;
777 struct st95_digital_cmd_complete_arg *cb_arg;
778
779 spidevice = &stcontext->spicontext.spidev->dev;
780
781 /*
782 * check semaphore, if not down() already, then we don't
783 * know in which context the ISR is called and surely it
784 * will be a bug. Note that down() of the semaphore is done
785 * in the corresponding st95hf_in_send_cmd() and then
786 * only this ISR should be called. ISR will up() the
787 * semaphore before leaving. Hence when the ISR is called
788 * the correct behaviour is down_trylock() should always
789 * return 1 (indicating semaphore cant be taken and hence no
790 * change in semaphore count).
791 * If not, then we up() the semaphore and crash on
792 * a BUG() !
793 */
794 if (!down_trylock(&stcontext->exchange_lock)) {
795 up(&stcontext->exchange_lock);
796 WARN(1, "unknown context in ST95HF ISR");
797 return IRQ_NONE;
798 }
799
800 cb_arg = &stcontext->complete_cb_arg;
801 skb_resp = cb_arg->skb_resp;
802
803 mutex_lock(&stcontext->rm_lock);
804 res_len = st95hf_spi_recv_response(&stcontext->spicontext,
805 skb_resp->data);
806 if (res_len < 0) {
807 dev_err(spidevice, "TISR spi response err = 0x%x\n", res_len);
808 result = res_len;
809 goto end;
810 }
811
812 /* if stcontext->nfcdev_free is true, it means remove already ran */
813 if (stcontext->nfcdev_free) {
814 result = -ENODEV;
815 goto end;
816 }
817
818 if (skb_resp->data[2] == WTX_REQ_FROM_TAG) {
819 /* Request for new FWT from tag */
820 result = st95hf_handle_wtx(stcontext, true, skb_resp->data[3]);
821 if (result)
822 goto end;
823
824 wtx = true;
825 mutex_unlock(&stcontext->rm_lock);
826 return IRQ_HANDLED;
827 }
828
829 result = st95hf_error_handling(stcontext, skb_resp, res_len);
830 if (result)
831 goto end;
832
833 result = st95hf_response_handler(stcontext, skb_resp, res_len);
834 if (result)
835 goto end;
836
837 /*
838 * If select protocol is done on wtx req. do select protocol
839 * again with default values
840 */
841 if (wtx) {
842 wtx = false;
843 result = st95hf_handle_wtx(stcontext, false, 0);
844 if (result)
845 goto end;
846 }
847
848 /* call digital layer callback */
849 cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
850
851 /* up the semaphore before returning */
852 up(&stcontext->exchange_lock);
853 mutex_unlock(&stcontext->rm_lock);
854
855 return IRQ_HANDLED;
856
857end:
858 kfree_skb(skb_resp);
859 wtx = false;
860 cb_arg->rats = false;
861 skb_resp = ERR_PTR(result);
862 /* call of callback with error */
863 cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
864 /* up the semaphore before returning */
865 up(&stcontext->exchange_lock);
866 mutex_unlock(&stcontext->rm_lock);
867 return IRQ_HANDLED;
868}
869
870/* NFC ops functions definition */
871static int st95hf_in_configure_hw(struct nfc_digital_dev *ddev,
872 int type,
873 int param)
874{
875 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
876
877 if (type == NFC_DIGITAL_CONFIG_RF_TECH)
878 return st95hf_select_protocol(stcontext, param);
879
880 if (type == NFC_DIGITAL_CONFIG_FRAMING) {
881 switch (param) {
882 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
883 stcontext->sendrcv_trflag = TRFLAG_NFCA_SHORT_FRAME;
884 break;
885 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
886 stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME;
887 break;
888 case NFC_DIGITAL_FRAMING_NFCA_T4T:
889 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
890 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
891 stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME_CRC;
892 break;
893 case NFC_DIGITAL_FRAMING_NFCB:
894 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
895 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
896 break;
897 }
898 }
899
900 return 0;
901}
902
903static int rf_off(struct st95hf_context *stcontext)
904{
905 int rc;
906 struct device *dev;
907
908 dev = &stcontext->nfcdev->dev;
909
910 rc = st95hf_send_recv_cmd(stcontext, CMD_FIELD_OFF, 0, NULL, true);
911 if (rc)
912 dev_err(dev, "protocol sel send field off, err = 0x%x\n", rc);
913
914 return rc;
915}
916
917static int st95hf_in_send_cmd(struct nfc_digital_dev *ddev,
918 struct sk_buff *skb,
919 u16 timeout,
920 nfc_digital_cmd_complete_t cb,
921 void *arg)
922{
923 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
924 int rc;
925 struct sk_buff *skb_resp;
926 int len_data_to_tag = 0;
927
928 skb_resp = nfc_alloc_recv_skb(MAX_RESPONSE_BUFFER_SIZE, GFP_KERNEL);
929 if (!skb_resp) {
930 rc = -ENOMEM;
931 goto error;
932 }
933
934 switch (stcontext->current_rf_tech) {
935 case NFC_DIGITAL_RF_TECH_106A:
936 len_data_to_tag = skb->len + 1;
937 skb_put_u8(skb, stcontext->sendrcv_trflag);
938 break;
939 case NFC_DIGITAL_RF_TECH_106B:
940 case NFC_DIGITAL_RF_TECH_ISO15693:
941 len_data_to_tag = skb->len;
942 break;
943 default:
944 rc = -EINVAL;
945 goto free_skb_resp;
946 }
947
948 skb_push(skb, 3);
949 skb->data[0] = ST95HF_COMMAND_SEND;
950 skb->data[1] = SEND_RECEIVE_CMD;
951 skb->data[2] = len_data_to_tag;
952
953 stcontext->complete_cb_arg.skb_resp = skb_resp;
954 stcontext->complete_cb_arg.cb_usrarg = arg;
955 stcontext->complete_cb_arg.complete_cb = cb;
956
957 if ((skb->data[3] == ISO14443A_RATS_REQ) &&
958 ddev->curr_protocol == NFC_PROTO_ISO14443)
959 stcontext->complete_cb_arg.rats = true;
960
961 /*
962 * down the semaphore to indicate to remove func that an
963 * ISR is pending, note that it will not block here in any case.
964 * If found blocked, it is a BUG!
965 */
966 rc = down_killable(&stcontext->exchange_lock);
967 if (rc) {
968 WARN(1, "Semaphore is not found up in st95hf_in_send_cmd\n");
969 goto free_skb_resp;
970 }
971
972 rc = st95hf_spi_send(&stcontext->spicontext, skb->data,
973 skb->len,
974 ASYNC);
975 if (rc) {
976 dev_err(&stcontext->nfcdev->dev,
977 "Error %d trying to perform data_exchange", rc);
978 /* up the semaphore since ISR will never come in this case */
979 up(&stcontext->exchange_lock);
980 goto free_skb_resp;
981 }
982
983 kfree_skb(skb);
984
985 return rc;
986
987free_skb_resp:
988 kfree_skb(skb_resp);
989error:
990 return rc;
991}
992
993/* p2p will be supported in a later release ! */
994static int st95hf_tg_configure_hw(struct nfc_digital_dev *ddev,
995 int type,
996 int param)
997{
998 return 0;
999}
1000
1001static int st95hf_tg_send_cmd(struct nfc_digital_dev *ddev,
1002 struct sk_buff *skb,
1003 u16 timeout,
1004 nfc_digital_cmd_complete_t cb,
1005 void *arg)
1006{
1007 return 0;
1008}
1009
1010static int st95hf_tg_listen(struct nfc_digital_dev *ddev,
1011 u16 timeout,
1012 nfc_digital_cmd_complete_t cb,
1013 void *arg)
1014{
1015 return 0;
1016}
1017
1018static int st95hf_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1019{
1020 return 0;
1021}
1022
1023static int st95hf_switch_rf(struct nfc_digital_dev *ddev, bool on)
1024{
1025 u8 rf_tech;
1026 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
1027
1028 rf_tech = ddev->curr_rf_tech;
1029
1030 if (on)
1031 /* switch on RF field */
1032 return st95hf_select_protocol(stcontext, rf_tech);
1033
1034 /* switch OFF RF field */
1035 return rf_off(stcontext);
1036}
1037
1038/* TODO st95hf_abort_cmd */
1039static void st95hf_abort_cmd(struct nfc_digital_dev *ddev)
1040{
1041}
1042
1043static struct nfc_digital_ops st95hf_nfc_digital_ops = {
1044 .in_configure_hw = st95hf_in_configure_hw,
1045 .in_send_cmd = st95hf_in_send_cmd,
1046
1047 .tg_listen = st95hf_tg_listen,
1048 .tg_configure_hw = st95hf_tg_configure_hw,
1049 .tg_send_cmd = st95hf_tg_send_cmd,
1050 .tg_get_rf_tech = st95hf_tg_get_rf_tech,
1051
1052 .switch_rf = st95hf_switch_rf,
1053 .abort_cmd = st95hf_abort_cmd,
1054};
1055
1056static const struct spi_device_id st95hf_id[] = {
1057 { "st95hf", 0 },
1058 {}
1059};
1060MODULE_DEVICE_TABLE(spi, st95hf_id);
1061
1062static const struct of_device_id st95hf_spi_of_match[] = {
1063 { .compatible = "st,st95hf" },
1064 { },
1065};
1066MODULE_DEVICE_TABLE(of, st95hf_spi_of_match);
1067
1068static int st95hf_probe(struct spi_device *nfc_spi_dev)
1069{
1070 int ret;
1071
1072 struct st95hf_context *st95context;
1073 struct st95hf_spi_context *spicontext;
1074
1075 nfc_info(&nfc_spi_dev->dev, "ST95HF driver probe called.\n");
1076
1077 st95context = devm_kzalloc(&nfc_spi_dev->dev,
1078 sizeof(struct st95hf_context),
1079 GFP_KERNEL);
1080 if (!st95context)
1081 return -ENOMEM;
1082
1083 spicontext = &st95context->spicontext;
1084
1085 spicontext->spidev = nfc_spi_dev;
1086
1087 st95context->fwi =
1088 cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[2];
1089
1090 if (device_property_present(&nfc_spi_dev->dev, "st95hfvin")) {
1091 st95context->st95hf_supply =
1092 devm_regulator_get(&nfc_spi_dev->dev,
1093 "st95hfvin");
1094 if (IS_ERR(st95context->st95hf_supply)) {
1095 dev_err(&nfc_spi_dev->dev, "failed to acquire regulator\n");
1096 return PTR_ERR(st95context->st95hf_supply);
1097 }
1098
1099 ret = regulator_enable(st95context->st95hf_supply);
1100 if (ret) {
1101 dev_err(&nfc_spi_dev->dev, "failed to enable regulator\n");
1102 return ret;
1103 }
1104 }
1105
1106 init_completion(&spicontext->done);
1107 mutex_init(&spicontext->spi_lock);
1108
1109 /*
1110 * Store spicontext in spi device object for using it in
1111 * remove function
1112 */
1113 dev_set_drvdata(&nfc_spi_dev->dev, spicontext);
1114
1115 st95context->enable_gpio =
1116 of_get_named_gpio(nfc_spi_dev->dev.of_node,
1117 "enable-gpio",
1118 0);
1119 if (!gpio_is_valid(st95context->enable_gpio)) {
1120 dev_err(&nfc_spi_dev->dev, "No valid enable gpio\n");
1121 ret = st95context->enable_gpio;
1122 goto err_disable_regulator;
1123 }
1124
1125 ret = devm_gpio_request_one(&nfc_spi_dev->dev, st95context->enable_gpio,
1126 GPIOF_DIR_OUT | GPIOF_INIT_HIGH,
1127 "enable_gpio");
1128 if (ret)
1129 goto err_disable_regulator;
1130
1131 if (nfc_spi_dev->irq > 0) {
1132 if (devm_request_threaded_irq(&nfc_spi_dev->dev,
1133 nfc_spi_dev->irq,
1134 st95hf_irq_handler,
1135 st95hf_irq_thread_handler,
1136 IRQF_TRIGGER_FALLING,
1137 "st95hf",
1138 (void *)st95context) < 0) {
1139 dev_err(&nfc_spi_dev->dev, "err: irq request for st95hf is failed\n");
1140 ret = -EINVAL;
1141 goto err_disable_regulator;
1142 }
1143 } else {
1144 dev_err(&nfc_spi_dev->dev, "not a valid IRQ associated with ST95HF\n");
1145 ret = -EINVAL;
1146 goto err_disable_regulator;
1147 }
1148
1149 /*
1150 * First reset SPI to handle warm reset of the system.
1151 * It will put the ST95HF device in Power ON state
1152 * which make the state of device identical to state
1153 * at the time of cold reset of the system.
1154 */
1155 ret = st95hf_send_spi_reset_sequence(st95context);
1156 if (ret) {
1157 dev_err(&nfc_spi_dev->dev, "err: spi_reset_sequence failed\n");
1158 goto err_disable_regulator;
1159 }
1160
1161 /* call PowerOnReset sequence of ST95hf to activate it */
1162 ret = st95hf_por_sequence(st95context);
1163 if (ret) {
1164 dev_err(&nfc_spi_dev->dev, "err: por seq failed for st95hf\n");
1165 goto err_disable_regulator;
1166 }
1167
1168 /* create NFC dev object and register with NFC Subsystem */
1169 st95context->ddev = nfc_digital_allocate_device(&st95hf_nfc_digital_ops,
1170 ST95HF_SUPPORTED_PROT,
1171 ST95HF_CAPABILITIES,
1172 ST95HF_HEADROOM_LEN,
1173 ST95HF_TAILROOM_LEN);
1174 if (!st95context->ddev) {
1175 ret = -ENOMEM;
1176 goto err_disable_regulator;
1177 }
1178
1179 st95context->nfcdev = st95context->ddev->nfc_dev;
1180 nfc_digital_set_parent_dev(st95context->ddev, &nfc_spi_dev->dev);
1181
1182 ret = nfc_digital_register_device(st95context->ddev);
1183 if (ret) {
1184 dev_err(&st95context->nfcdev->dev, "st95hf registration failed\n");
1185 goto err_free_digital_device;
1186 }
1187
1188 /* store st95context in nfc device object */
1189 nfc_digital_set_drvdata(st95context->ddev, st95context);
1190
1191 sema_init(&st95context->exchange_lock, 1);
1192 mutex_init(&st95context->rm_lock);
1193
1194 return ret;
1195
1196err_free_digital_device:
1197 nfc_digital_free_device(st95context->ddev);
1198err_disable_regulator:
1199 if (st95context->st95hf_supply)
1200 regulator_disable(st95context->st95hf_supply);
1201
1202 return ret;
1203}
1204
1205static int st95hf_remove(struct spi_device *nfc_spi_dev)
1206{
1207 int result = 0;
1208 unsigned char reset_cmd = ST95HF_COMMAND_RESET;
1209 struct st95hf_spi_context *spictx = dev_get_drvdata(&nfc_spi_dev->dev);
1210
1211 struct st95hf_context *stcontext = container_of(spictx,
1212 struct st95hf_context,
1213 spicontext);
1214
1215 mutex_lock(&stcontext->rm_lock);
1216
1217 nfc_digital_unregister_device(stcontext->ddev);
1218 nfc_digital_free_device(stcontext->ddev);
1219 stcontext->nfcdev_free = true;
1220
1221 mutex_unlock(&stcontext->rm_lock);
1222
1223 /* if last in_send_cmd's ISR is pending, wait for it to finish */
1224 result = down_killable(&stcontext->exchange_lock);
1225 if (result == -EINTR)
1226 dev_err(&spictx->spidev->dev, "sleep for semaphore interrupted by signal\n");
1227
1228 /* next reset the ST95HF controller */
1229 result = st95hf_spi_send(&stcontext->spicontext,
1230 &reset_cmd,
1231 ST95HF_RESET_CMD_LEN,
1232 ASYNC);
1233 if (result) {
1234 dev_err(&spictx->spidev->dev,
1235 "ST95HF reset failed in remove() err = %d\n", result);
1236 return result;
1237 }
1238
1239 /* wait for 3 ms to complete the controller reset process */
1240 usleep_range(3000, 4000);
1241
1242 /* disable regulator */
1243 if (stcontext->st95hf_supply)
1244 regulator_disable(stcontext->st95hf_supply);
1245
1246 return result;
1247}
1248
1249/* Register as SPI protocol driver */
1250static struct spi_driver st95hf_driver = {
1251 .driver = {
1252 .name = "st95hf",
1253 .owner = THIS_MODULE,
1254 .of_match_table = of_match_ptr(st95hf_spi_of_match),
1255 },
1256 .id_table = st95hf_id,
1257 .probe = st95hf_probe,
1258 .remove = st95hf_remove,
1259};
1260
1261module_spi_driver(st95hf_driver);
1262
1263MODULE_AUTHOR("Shikha Singh <shikha.singh@st.com>");
1264MODULE_DESCRIPTION("ST NFC Transceiver ST95HF driver");
1265MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * --------------------------------------------------------------------
4 * Driver for ST NFC Transceiver ST95HF
5 * --------------------------------------------------------------------
6 * Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved.
7 */
8
9#include <linux/err.h>
10#include <linux/gpio/consumer.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/module.h>
15#include <linux/netdevice.h>
16#include <linux/nfc.h>
17#include <linux/of.h>
18#include <linux/property.h>
19#include <linux/regulator/consumer.h>
20#include <linux/wait.h>
21#include <net/nfc/digital.h>
22#include <net/nfc/nfc.h>
23
24#include "spi.h"
25
26/* supported protocols */
27#define ST95HF_SUPPORTED_PROT (NFC_PROTO_ISO14443_MASK | \
28 NFC_PROTO_ISO14443_B_MASK | \
29 NFC_PROTO_ISO15693_MASK)
30/* driver capabilities */
31#define ST95HF_CAPABILITIES NFC_DIGITAL_DRV_CAPS_IN_CRC
32
33/* Command Send Interface */
34/* ST95HF_COMMAND_SEND CMD Ids */
35#define ECHO_CMD 0x55
36#define WRITE_REGISTER_CMD 0x9
37#define PROTOCOL_SELECT_CMD 0x2
38#define SEND_RECEIVE_CMD 0x4
39
40/* Select protocol codes */
41#define ISO15693_PROTOCOL_CODE 0x1
42#define ISO14443A_PROTOCOL_CODE 0x2
43#define ISO14443B_PROTOCOL_CODE 0x3
44
45/*
46 * head room len is 3
47 * 1 byte for control byte
48 * 1 byte for cmd
49 * 1 byte for size
50 */
51#define ST95HF_HEADROOM_LEN 3
52
53/*
54 * tailroom is 1 for ISO14443A
55 * and 0 for ISO14443B/ISO15693,
56 * hence the max value 1 should be
57 * taken.
58 */
59#define ST95HF_TAILROOM_LEN 1
60
61/* Command Response interface */
62#define MAX_RESPONSE_BUFFER_SIZE 280
63#define ECHORESPONSE 0x55
64#define ST95HF_ERR_MASK 0xF
65#define ST95HF_TIMEOUT_ERROR 0x87
66#define ST95HF_NFCA_CRC_ERR_MASK 0x20
67#define ST95HF_NFCB_CRC_ERR_MASK 0x01
68
69/* ST95HF transmission flag values */
70#define TRFLAG_NFCA_SHORT_FRAME 0x07
71#define TRFLAG_NFCA_STD_FRAME 0x08
72#define TRFLAG_NFCA_STD_FRAME_CRC 0x28
73
74/* Misc defs */
75#define HIGH 1
76#define LOW 0
77#define ISO14443A_RATS_REQ 0xE0
78#define RATS_TB1_PRESENT_MASK 0x20
79#define RATS_TA1_PRESENT_MASK 0x10
80#define TB1_FWI_MASK 0xF0
81#define WTX_REQ_FROM_TAG 0xF2
82
83#define MAX_CMD_LEN 0x7
84
85#define MAX_CMD_PARAMS 4
86struct cmd {
87 int cmd_len;
88 unsigned char cmd_id;
89 unsigned char no_cmd_params;
90 unsigned char cmd_params[MAX_CMD_PARAMS];
91 enum req_type req;
92};
93
94struct param_list {
95 int param_offset;
96 int new_param_val;
97};
98
99/*
100 * List of top-level cmds to be used internally by the driver.
101 * All these commands are build on top of ST95HF basic commands
102 * such as SEND_RECEIVE_CMD, PROTOCOL_SELECT_CMD, etc.
103 * These top level cmds are used internally while implementing various ops of
104 * digital layer/driver probe or extending the digital framework layer for
105 * features that are not yet implemented there, for example, WTX cmd handling.
106 */
107enum st95hf_cmd_list {
108 CMD_ECHO,
109 CMD_ISO14443A_CONFIG,
110 CMD_ISO14443A_DEMOGAIN,
111 CMD_ISO14443B_DEMOGAIN,
112 CMD_ISO14443A_PROTOCOL_SELECT,
113 CMD_ISO14443B_PROTOCOL_SELECT,
114 CMD_WTX_RESPONSE,
115 CMD_FIELD_OFF,
116 CMD_ISO15693_PROTOCOL_SELECT,
117};
118
119static const struct cmd cmd_array[] = {
120 [CMD_ECHO] = {
121 .cmd_len = 0x2,
122 .cmd_id = ECHO_CMD,
123 .no_cmd_params = 0,
124 .req = SYNC,
125 },
126 [CMD_ISO14443A_CONFIG] = {
127 .cmd_len = 0x7,
128 .cmd_id = WRITE_REGISTER_CMD,
129 .no_cmd_params = 0x4,
130 .cmd_params = {0x3A, 0x00, 0x5A, 0x04},
131 .req = SYNC,
132 },
133 [CMD_ISO14443A_DEMOGAIN] = {
134 .cmd_len = 0x7,
135 .cmd_id = WRITE_REGISTER_CMD,
136 .no_cmd_params = 0x4,
137 .cmd_params = {0x68, 0x01, 0x01, 0xDF},
138 .req = SYNC,
139 },
140 [CMD_ISO14443B_DEMOGAIN] = {
141 .cmd_len = 0x7,
142 .cmd_id = WRITE_REGISTER_CMD,
143 .no_cmd_params = 0x4,
144 .cmd_params = {0x68, 0x01, 0x01, 0x51},
145 .req = SYNC,
146 },
147 [CMD_ISO14443A_PROTOCOL_SELECT] = {
148 .cmd_len = 0x7,
149 .cmd_id = PROTOCOL_SELECT_CMD,
150 .no_cmd_params = 0x4,
151 .cmd_params = {ISO14443A_PROTOCOL_CODE, 0x00, 0x01, 0xA0},
152 .req = SYNC,
153 },
154 [CMD_ISO14443B_PROTOCOL_SELECT] = {
155 .cmd_len = 0x7,
156 .cmd_id = PROTOCOL_SELECT_CMD,
157 .no_cmd_params = 0x4,
158 .cmd_params = {ISO14443B_PROTOCOL_CODE, 0x01, 0x03, 0xFF},
159 .req = SYNC,
160 },
161 [CMD_WTX_RESPONSE] = {
162 .cmd_len = 0x6,
163 .cmd_id = SEND_RECEIVE_CMD,
164 .no_cmd_params = 0x3,
165 .cmd_params = {0xF2, 0x00, TRFLAG_NFCA_STD_FRAME_CRC},
166 .req = ASYNC,
167 },
168 [CMD_FIELD_OFF] = {
169 .cmd_len = 0x5,
170 .cmd_id = PROTOCOL_SELECT_CMD,
171 .no_cmd_params = 0x2,
172 .cmd_params = {0x0, 0x0},
173 .req = SYNC,
174 },
175 [CMD_ISO15693_PROTOCOL_SELECT] = {
176 .cmd_len = 0x5,
177 .cmd_id = PROTOCOL_SELECT_CMD,
178 .no_cmd_params = 0x2,
179 .cmd_params = {ISO15693_PROTOCOL_CODE, 0x0D},
180 .req = SYNC,
181 },
182};
183
184/* st95_digital_cmd_complete_arg stores client context */
185struct st95_digital_cmd_complete_arg {
186 struct sk_buff *skb_resp;
187 nfc_digital_cmd_complete_t complete_cb;
188 void *cb_usrarg;
189 bool rats;
190};
191
192/*
193 * structure containing ST95HF driver specific data.
194 * @spicontext: structure containing information required
195 * for spi communication between st95hf and host.
196 * @ddev: nfc digital device object.
197 * @nfcdev: nfc device object.
198 * @enable_gpiod: gpio used to enable st95hf transceiver.
199 * @complete_cb_arg: structure to store various context information
200 * that is passed from nfc requesting thread to the threaded ISR.
201 * @st95hf_supply: regulator "consumer" for NFC device.
202 * @sendrcv_trflag: last byte of frame send by sendrecv command
203 * of st95hf. This byte contains transmission flag info.
204 * @exchange_lock: semaphore used for signaling the st95hf_remove
205 * function that the last outstanding async nfc request is finished.
206 * @rm_lock: mutex for ensuring safe access of nfc digital object
207 * from threaded ISR. Usage of this mutex avoids any race between
208 * deletion of the object from st95hf_remove() and its access from
209 * the threaded ISR.
210 * @nfcdev_free: flag to have the state of nfc device object.
211 * [alive | died]
212 * @current_protocol: current nfc protocol.
213 * @current_rf_tech: current rf technology.
214 * @fwi: frame waiting index, received in reply of RATS according to
215 * digital protocol.
216 */
217struct st95hf_context {
218 struct st95hf_spi_context spicontext;
219 struct nfc_digital_dev *ddev;
220 struct nfc_dev *nfcdev;
221 struct gpio_desc *enable_gpiod;
222 struct st95_digital_cmd_complete_arg complete_cb_arg;
223 struct regulator *st95hf_supply;
224 unsigned char sendrcv_trflag;
225 struct semaphore exchange_lock;
226 struct mutex rm_lock;
227 bool nfcdev_free;
228 u8 current_protocol;
229 u8 current_rf_tech;
230 int fwi;
231};
232
233/*
234 * st95hf_send_recv_cmd() is for sending commands to ST95HF
235 * that are described in the cmd_array[]. It can optionally
236 * receive the response if the cmd request is of type
237 * SYNC. For that to happen caller must pass true to recv_res.
238 * For ASYNC request, recv_res is ignored and the
239 * function will never try to receive the response on behalf
240 * of the caller.
241 */
242static int st95hf_send_recv_cmd(struct st95hf_context *st95context,
243 enum st95hf_cmd_list cmd,
244 int no_modif,
245 struct param_list *list_array,
246 bool recv_res)
247{
248 unsigned char spi_cmd_buffer[MAX_CMD_LEN];
249 int i, ret;
250 struct device *dev = &st95context->spicontext.spidev->dev;
251
252 if (cmd_array[cmd].cmd_len > MAX_CMD_LEN)
253 return -EINVAL;
254 if (cmd_array[cmd].no_cmd_params < no_modif)
255 return -EINVAL;
256 if (no_modif && !list_array)
257 return -EINVAL;
258
259 spi_cmd_buffer[0] = ST95HF_COMMAND_SEND;
260 spi_cmd_buffer[1] = cmd_array[cmd].cmd_id;
261 spi_cmd_buffer[2] = cmd_array[cmd].no_cmd_params;
262
263 memcpy(&spi_cmd_buffer[3], cmd_array[cmd].cmd_params,
264 spi_cmd_buffer[2]);
265
266 for (i = 0; i < no_modif; i++) {
267 if (list_array[i].param_offset >= cmd_array[cmd].no_cmd_params)
268 return -EINVAL;
269 spi_cmd_buffer[3 + list_array[i].param_offset] =
270 list_array[i].new_param_val;
271 }
272
273 ret = st95hf_spi_send(&st95context->spicontext,
274 spi_cmd_buffer,
275 cmd_array[cmd].cmd_len,
276 cmd_array[cmd].req);
277 if (ret) {
278 dev_err(dev, "st95hf_spi_send failed with error %d\n", ret);
279 return ret;
280 }
281
282 if (cmd_array[cmd].req == SYNC && recv_res) {
283 unsigned char st95hf_response_arr[2];
284
285 ret = st95hf_spi_recv_response(&st95context->spicontext,
286 st95hf_response_arr);
287 if (ret < 0) {
288 dev_err(dev, "spi error from st95hf_spi_recv_response(), err = 0x%x\n",
289 ret);
290 return ret;
291 }
292
293 if (st95hf_response_arr[0]) {
294 dev_err(dev, "st95hf error from st95hf_spi_recv_response(), err = 0x%x\n",
295 st95hf_response_arr[0]);
296 return -EIO;
297 }
298 }
299
300 return 0;
301}
302
303static int st95hf_echo_command(struct st95hf_context *st95context)
304{
305 int result = 0;
306 unsigned char echo_response;
307
308 result = st95hf_send_recv_cmd(st95context, CMD_ECHO, 0, NULL, false);
309 if (result)
310 return result;
311
312 /* If control reached here, response can be taken */
313 result = st95hf_spi_recv_echo_res(&st95context->spicontext,
314 &echo_response);
315 if (result) {
316 dev_err(&st95context->spicontext.spidev->dev,
317 "err: echo response receive error = 0x%x\n", result);
318 return result;
319 }
320
321 if (echo_response == ECHORESPONSE)
322 return 0;
323
324 dev_err(&st95context->spicontext.spidev->dev, "err: echo res is 0x%x\n",
325 echo_response);
326
327 return -EIO;
328}
329
330static int secondary_configuration_type4a(struct st95hf_context *stcontext)
331{
332 int result = 0;
333 struct device *dev = &stcontext->nfcdev->dev;
334
335 /* 14443A config setting after select protocol */
336 result = st95hf_send_recv_cmd(stcontext,
337 CMD_ISO14443A_CONFIG,
338 0,
339 NULL,
340 true);
341 if (result) {
342 dev_err(dev, "type a config cmd, err = 0x%x\n", result);
343 return result;
344 }
345
346 /* 14443A demo gain setting */
347 result = st95hf_send_recv_cmd(stcontext,
348 CMD_ISO14443A_DEMOGAIN,
349 0,
350 NULL,
351 true);
352 if (result)
353 dev_err(dev, "type a demogain cmd, err = 0x%x\n", result);
354
355 return result;
356}
357
358static int secondary_configuration_type4b(struct st95hf_context *stcontext)
359{
360 int result = 0;
361 struct device *dev = &stcontext->nfcdev->dev;
362
363 result = st95hf_send_recv_cmd(stcontext,
364 CMD_ISO14443B_DEMOGAIN,
365 0,
366 NULL,
367 true);
368 if (result)
369 dev_err(dev, "type b demogain cmd, err = 0x%x\n", result);
370
371 return result;
372}
373
374static int st95hf_select_protocol(struct st95hf_context *stcontext, int type)
375{
376 int result = 0;
377 struct device *dev;
378
379 dev = &stcontext->nfcdev->dev;
380
381 switch (type) {
382 case NFC_DIGITAL_RF_TECH_106A:
383 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106A;
384 result = st95hf_send_recv_cmd(stcontext,
385 CMD_ISO14443A_PROTOCOL_SELECT,
386 0,
387 NULL,
388 true);
389 if (result) {
390 dev_err(dev, "protocol sel, err = 0x%x\n",
391 result);
392 return result;
393 }
394
395 /* secondary config. for 14443Type 4A after protocol select */
396 result = secondary_configuration_type4a(stcontext);
397 if (result) {
398 dev_err(dev, "type a secondary config, err = 0x%x\n",
399 result);
400 return result;
401 }
402 break;
403 case NFC_DIGITAL_RF_TECH_106B:
404 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_106B;
405 result = st95hf_send_recv_cmd(stcontext,
406 CMD_ISO14443B_PROTOCOL_SELECT,
407 0,
408 NULL,
409 true);
410 if (result) {
411 dev_err(dev, "protocol sel send, err = 0x%x\n",
412 result);
413 return result;
414 }
415
416 /*
417 * delay of 5-6 ms is required after select protocol
418 * command in case of ISO14443 Type B
419 */
420 usleep_range(50000, 60000);
421
422 /* secondary config. for 14443Type 4B after protocol select */
423 result = secondary_configuration_type4b(stcontext);
424 if (result) {
425 dev_err(dev, "type b secondary config, err = 0x%x\n",
426 result);
427 return result;
428 }
429 break;
430 case NFC_DIGITAL_RF_TECH_ISO15693:
431 stcontext->current_rf_tech = NFC_DIGITAL_RF_TECH_ISO15693;
432 result = st95hf_send_recv_cmd(stcontext,
433 CMD_ISO15693_PROTOCOL_SELECT,
434 0,
435 NULL,
436 true);
437 if (result) {
438 dev_err(dev, "protocol sel send, err = 0x%x\n",
439 result);
440 return result;
441 }
442 break;
443 default:
444 return -EINVAL;
445 }
446
447 return 0;
448}
449
450static void st95hf_send_st95enable_negativepulse(struct st95hf_context *st95con)
451{
452 /* First make irq_in pin high */
453 gpiod_set_value(st95con->enable_gpiod, HIGH);
454
455 /* wait for 1 milisecond */
456 usleep_range(1000, 2000);
457
458 /* Make irq_in pin low */
459 gpiod_set_value(st95con->enable_gpiod, LOW);
460
461 /* wait for minimum interrupt pulse to make st95 active */
462 usleep_range(1000, 2000);
463
464 /* At end make it high */
465 gpiod_set_value(st95con->enable_gpiod, HIGH);
466}
467
468/*
469 * Send a reset sequence over SPI bus (Reset command + wait 3ms +
470 * negative pulse on st95hf enable gpio
471 */
472static int st95hf_send_spi_reset_sequence(struct st95hf_context *st95context)
473{
474 int result = 0;
475 unsigned char reset_cmd = ST95HF_COMMAND_RESET;
476
477 result = st95hf_spi_send(&st95context->spicontext,
478 &reset_cmd,
479 ST95HF_RESET_CMD_LEN,
480 ASYNC);
481 if (result) {
482 dev_err(&st95context->spicontext.spidev->dev,
483 "spi reset sequence cmd error = %d", result);
484 return result;
485 }
486
487 /* wait for 3 milisecond to complete the controller reset process */
488 usleep_range(3000, 4000);
489
490 /* send negative pulse to make st95hf active */
491 st95hf_send_st95enable_negativepulse(st95context);
492
493 /* wait for 10 milisecond : HFO setup time */
494 usleep_range(10000, 20000);
495
496 return result;
497}
498
499static int st95hf_por_sequence(struct st95hf_context *st95context)
500{
501 int nth_attempt = 1;
502 int result;
503
504 st95hf_send_st95enable_negativepulse(st95context);
505
506 usleep_range(5000, 6000);
507 do {
508 /* send an ECHO command and checks ST95HF response */
509 result = st95hf_echo_command(st95context);
510
511 dev_dbg(&st95context->spicontext.spidev->dev,
512 "response from echo function = 0x%x, attempt = %d\n",
513 result, nth_attempt);
514
515 if (!result)
516 return 0;
517
518 /* send an pulse on IRQ in case of the chip is on sleep state */
519 if (nth_attempt == 2)
520 st95hf_send_st95enable_negativepulse(st95context);
521 else
522 st95hf_send_spi_reset_sequence(st95context);
523
524 /* delay of 50 milisecond */
525 usleep_range(50000, 51000);
526 } while (nth_attempt++ < 3);
527
528 return -ETIMEDOUT;
529}
530
531static int iso14443_config_fdt(struct st95hf_context *st95context, int wtxm)
532{
533 int result = 0;
534 struct device *dev = &st95context->spicontext.spidev->dev;
535 struct nfc_digital_dev *nfcddev = st95context->ddev;
536 unsigned char pp_typeb;
537 struct param_list new_params[2];
538
539 pp_typeb = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[2];
540
541 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 &&
542 st95context->fwi < 4)
543 st95context->fwi = 4;
544
545 new_params[0].param_offset = 2;
546 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
547 new_params[0].new_param_val = st95context->fwi;
548 else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
549 new_params[0].new_param_val = pp_typeb;
550
551 new_params[1].param_offset = 3;
552 new_params[1].new_param_val = wtxm;
553
554 switch (nfcddev->curr_protocol) {
555 case NFC_PROTO_ISO14443:
556 result = st95hf_send_recv_cmd(st95context,
557 CMD_ISO14443A_PROTOCOL_SELECT,
558 2,
559 new_params,
560 true);
561 if (result) {
562 dev_err(dev, "WTX type a sel proto, err = 0x%x\n",
563 result);
564 return result;
565 }
566
567 /* secondary config. for 14443Type 4A after protocol select */
568 result = secondary_configuration_type4a(st95context);
569 if (result) {
570 dev_err(dev, "WTX type a second. config, err = 0x%x\n",
571 result);
572 return result;
573 }
574 break;
575 case NFC_PROTO_ISO14443_B:
576 result = st95hf_send_recv_cmd(st95context,
577 CMD_ISO14443B_PROTOCOL_SELECT,
578 2,
579 new_params,
580 true);
581 if (result) {
582 dev_err(dev, "WTX type b sel proto, err = 0x%x\n",
583 result);
584 return result;
585 }
586
587 /* secondary config. for 14443Type 4B after protocol select */
588 result = secondary_configuration_type4b(st95context);
589 if (result) {
590 dev_err(dev, "WTX type b second. config, err = 0x%x\n",
591 result);
592 return result;
593 }
594 break;
595 default:
596 return -EINVAL;
597 }
598
599 return 0;
600}
601
602static int st95hf_handle_wtx(struct st95hf_context *stcontext,
603 bool new_wtx,
604 int wtx_val)
605{
606 int result = 0;
607 unsigned char val_mm = 0;
608 struct param_list new_params[1];
609 struct nfc_digital_dev *nfcddev = stcontext->ddev;
610 struct device *dev = &stcontext->nfcdev->dev;
611
612 if (new_wtx) {
613 result = iso14443_config_fdt(stcontext, wtx_val & 0x3f);
614 if (result) {
615 dev_err(dev, "Config. setting error on WTX req, err = 0x%x\n",
616 result);
617 return result;
618 }
619
620 /* Send response of wtx with ASYNC as no response expected */
621 new_params[0].param_offset = 1;
622 new_params[0].new_param_val = wtx_val;
623
624 result = st95hf_send_recv_cmd(stcontext,
625 CMD_WTX_RESPONSE,
626 1,
627 new_params,
628 false);
629 if (result)
630 dev_err(dev, "WTX response send, err = 0x%x\n", result);
631 return result;
632 }
633
634 /* if no new wtx, cofigure with default values */
635 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443)
636 val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
637 else if (nfcddev->curr_protocol == NFC_PROTO_ISO14443_B)
638 val_mm = cmd_array[CMD_ISO14443B_PROTOCOL_SELECT].cmd_params[3];
639
640 result = iso14443_config_fdt(stcontext, val_mm);
641 if (result)
642 dev_err(dev, "Default config. setting error after WTX processing, err = 0x%x\n",
643 result);
644
645 return result;
646}
647
648static int st95hf_error_handling(struct st95hf_context *stcontext,
649 struct sk_buff *skb_resp,
650 int res_len)
651{
652 int result = 0;
653 unsigned char error_byte;
654 struct device *dev = &stcontext->nfcdev->dev;
655
656 /* First check ST95HF specific error */
657 if (skb_resp->data[0] & ST95HF_ERR_MASK) {
658 if (skb_resp->data[0] == ST95HF_TIMEOUT_ERROR)
659 result = -ETIMEDOUT;
660 else
661 result = -EIO;
662 return result;
663 }
664
665 /* Check for CRC err only if CRC is present in the tag response */
666 switch (stcontext->current_rf_tech) {
667 case NFC_DIGITAL_RF_TECH_106A:
668 if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC) {
669 error_byte = skb_resp->data[res_len - 3];
670 if (error_byte & ST95HF_NFCA_CRC_ERR_MASK) {
671 /* CRC error occurred */
672 dev_err(dev, "CRC error, byte received = 0x%x\n",
673 error_byte);
674 result = -EIO;
675 }
676 }
677 break;
678 case NFC_DIGITAL_RF_TECH_106B:
679 case NFC_DIGITAL_RF_TECH_ISO15693:
680 error_byte = skb_resp->data[res_len - 1];
681 if (error_byte & ST95HF_NFCB_CRC_ERR_MASK) {
682 /* CRC error occurred */
683 dev_err(dev, "CRC error, byte received = 0x%x\n",
684 error_byte);
685 result = -EIO;
686 }
687 break;
688 }
689
690 return result;
691}
692
693static int st95hf_response_handler(struct st95hf_context *stcontext,
694 struct sk_buff *skb_resp,
695 int res_len)
696{
697 int result = 0;
698 int skb_len;
699 unsigned char val_mm;
700 struct nfc_digital_dev *nfcddev = stcontext->ddev;
701 struct device *dev = &stcontext->nfcdev->dev;
702 struct st95_digital_cmd_complete_arg *cb_arg;
703
704 cb_arg = &stcontext->complete_cb_arg;
705
706 /* Process the response */
707 skb_put(skb_resp, res_len);
708
709 /* Remove st95 header */
710 skb_pull(skb_resp, 2);
711
712 skb_len = skb_resp->len;
713
714 /* check if it is case of RATS request reply & FWI is present */
715 if (nfcddev->curr_protocol == NFC_PROTO_ISO14443 && cb_arg->rats &&
716 (skb_resp->data[1] & RATS_TB1_PRESENT_MASK)) {
717 if (skb_resp->data[1] & RATS_TA1_PRESENT_MASK)
718 stcontext->fwi =
719 (skb_resp->data[3] & TB1_FWI_MASK) >> 4;
720 else
721 stcontext->fwi =
722 (skb_resp->data[2] & TB1_FWI_MASK) >> 4;
723
724 val_mm = cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[3];
725
726 result = iso14443_config_fdt(stcontext, val_mm);
727 if (result) {
728 dev_err(dev, "error in config_fdt to handle fwi of ATS, error=%d\n",
729 result);
730 return result;
731 }
732 }
733 cb_arg->rats = false;
734
735 /* Remove CRC bytes only if received frames data has an eod (CRC) */
736 switch (stcontext->current_rf_tech) {
737 case NFC_DIGITAL_RF_TECH_106A:
738 if (stcontext->sendrcv_trflag == TRFLAG_NFCA_STD_FRAME_CRC)
739 skb_trim(skb_resp, (skb_len - 5));
740 else
741 skb_trim(skb_resp, (skb_len - 3));
742 break;
743 case NFC_DIGITAL_RF_TECH_106B:
744 case NFC_DIGITAL_RF_TECH_ISO15693:
745 skb_trim(skb_resp, (skb_len - 3));
746 break;
747 }
748
749 return result;
750}
751
752static irqreturn_t st95hf_irq_handler(int irq, void *st95hfcontext)
753{
754 struct st95hf_context *stcontext =
755 (struct st95hf_context *)st95hfcontext;
756
757 if (stcontext->spicontext.req_issync) {
758 complete(&stcontext->spicontext.done);
759 stcontext->spicontext.req_issync = false;
760 return IRQ_HANDLED;
761 }
762
763 return IRQ_WAKE_THREAD;
764}
765
766static irqreturn_t st95hf_irq_thread_handler(int irq, void *st95hfcontext)
767{
768 int result = 0;
769 int res_len;
770 static bool wtx;
771 struct device *spidevice;
772 struct sk_buff *skb_resp;
773 struct st95hf_context *stcontext =
774 (struct st95hf_context *)st95hfcontext;
775 struct st95_digital_cmd_complete_arg *cb_arg;
776
777 spidevice = &stcontext->spicontext.spidev->dev;
778
779 /*
780 * check semaphore, if not down() already, then we don't
781 * know in which context the ISR is called and surely it
782 * will be a bug. Note that down() of the semaphore is done
783 * in the corresponding st95hf_in_send_cmd() and then
784 * only this ISR should be called. ISR will up() the
785 * semaphore before leaving. Hence when the ISR is called
786 * the correct behaviour is down_trylock() should always
787 * return 1 (indicating semaphore cant be taken and hence no
788 * change in semaphore count).
789 * If not, then we up() the semaphore and crash on
790 * a BUG() !
791 */
792 if (!down_trylock(&stcontext->exchange_lock)) {
793 up(&stcontext->exchange_lock);
794 WARN(1, "unknown context in ST95HF ISR");
795 return IRQ_NONE;
796 }
797
798 cb_arg = &stcontext->complete_cb_arg;
799 skb_resp = cb_arg->skb_resp;
800
801 mutex_lock(&stcontext->rm_lock);
802 res_len = st95hf_spi_recv_response(&stcontext->spicontext,
803 skb_resp->data);
804 if (res_len < 0) {
805 dev_err(spidevice, "TISR spi response err = 0x%x\n", res_len);
806 result = res_len;
807 goto end;
808 }
809
810 /* if stcontext->nfcdev_free is true, it means remove already ran */
811 if (stcontext->nfcdev_free) {
812 result = -ENODEV;
813 goto end;
814 }
815
816 if (skb_resp->data[2] == WTX_REQ_FROM_TAG) {
817 /* Request for new FWT from tag */
818 result = st95hf_handle_wtx(stcontext, true, skb_resp->data[3]);
819 if (result)
820 goto end;
821
822 wtx = true;
823 mutex_unlock(&stcontext->rm_lock);
824 return IRQ_HANDLED;
825 }
826
827 result = st95hf_error_handling(stcontext, skb_resp, res_len);
828 if (result)
829 goto end;
830
831 result = st95hf_response_handler(stcontext, skb_resp, res_len);
832 if (result)
833 goto end;
834
835 /*
836 * If select protocol is done on wtx req. do select protocol
837 * again with default values
838 */
839 if (wtx) {
840 wtx = false;
841 result = st95hf_handle_wtx(stcontext, false, 0);
842 if (result)
843 goto end;
844 }
845
846 /* call digital layer callback */
847 cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
848
849 /* up the semaphore before returning */
850 up(&stcontext->exchange_lock);
851 mutex_unlock(&stcontext->rm_lock);
852
853 return IRQ_HANDLED;
854
855end:
856 kfree_skb(skb_resp);
857 wtx = false;
858 cb_arg->rats = false;
859 skb_resp = ERR_PTR(result);
860 /* call of callback with error */
861 cb_arg->complete_cb(stcontext->ddev, cb_arg->cb_usrarg, skb_resp);
862 /* up the semaphore before returning */
863 up(&stcontext->exchange_lock);
864 mutex_unlock(&stcontext->rm_lock);
865 return IRQ_HANDLED;
866}
867
868/* NFC ops functions definition */
869static int st95hf_in_configure_hw(struct nfc_digital_dev *ddev,
870 int type,
871 int param)
872{
873 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
874
875 if (type == NFC_DIGITAL_CONFIG_RF_TECH)
876 return st95hf_select_protocol(stcontext, param);
877
878 if (type == NFC_DIGITAL_CONFIG_FRAMING) {
879 switch (param) {
880 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
881 stcontext->sendrcv_trflag = TRFLAG_NFCA_SHORT_FRAME;
882 break;
883 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
884 stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME;
885 break;
886 case NFC_DIGITAL_FRAMING_NFCA_T4T:
887 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
888 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
889 stcontext->sendrcv_trflag = TRFLAG_NFCA_STD_FRAME_CRC;
890 break;
891 case NFC_DIGITAL_FRAMING_NFCB:
892 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
893 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
894 break;
895 }
896 }
897
898 return 0;
899}
900
901static int rf_off(struct st95hf_context *stcontext)
902{
903 int rc;
904 struct device *dev;
905
906 dev = &stcontext->nfcdev->dev;
907
908 rc = st95hf_send_recv_cmd(stcontext, CMD_FIELD_OFF, 0, NULL, true);
909 if (rc)
910 dev_err(dev, "protocol sel send field off, err = 0x%x\n", rc);
911
912 return rc;
913}
914
915static int st95hf_in_send_cmd(struct nfc_digital_dev *ddev,
916 struct sk_buff *skb,
917 u16 timeout,
918 nfc_digital_cmd_complete_t cb,
919 void *arg)
920{
921 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
922 int rc;
923 struct sk_buff *skb_resp;
924 int len_data_to_tag = 0;
925
926 skb_resp = nfc_alloc_recv_skb(MAX_RESPONSE_BUFFER_SIZE, GFP_KERNEL);
927 if (!skb_resp)
928 return -ENOMEM;
929
930 switch (stcontext->current_rf_tech) {
931 case NFC_DIGITAL_RF_TECH_106A:
932 len_data_to_tag = skb->len + 1;
933 skb_put_u8(skb, stcontext->sendrcv_trflag);
934 break;
935 case NFC_DIGITAL_RF_TECH_106B:
936 case NFC_DIGITAL_RF_TECH_ISO15693:
937 len_data_to_tag = skb->len;
938 break;
939 default:
940 rc = -EINVAL;
941 goto free_skb_resp;
942 }
943
944 skb_push(skb, 3);
945 skb->data[0] = ST95HF_COMMAND_SEND;
946 skb->data[1] = SEND_RECEIVE_CMD;
947 skb->data[2] = len_data_to_tag;
948
949 stcontext->complete_cb_arg.skb_resp = skb_resp;
950 stcontext->complete_cb_arg.cb_usrarg = arg;
951 stcontext->complete_cb_arg.complete_cb = cb;
952
953 if ((skb->data[3] == ISO14443A_RATS_REQ) &&
954 ddev->curr_protocol == NFC_PROTO_ISO14443)
955 stcontext->complete_cb_arg.rats = true;
956
957 /*
958 * down the semaphore to indicate to remove func that an
959 * ISR is pending, note that it will not block here in any case.
960 * If found blocked, it is a BUG!
961 */
962 rc = down_killable(&stcontext->exchange_lock);
963 if (rc) {
964 WARN(1, "Semaphore is not found up in st95hf_in_send_cmd\n");
965 goto free_skb_resp;
966 }
967
968 rc = st95hf_spi_send(&stcontext->spicontext, skb->data,
969 skb->len,
970 ASYNC);
971 if (rc) {
972 dev_err(&stcontext->nfcdev->dev,
973 "Error %d trying to perform data_exchange", rc);
974 /* up the semaphore since ISR will never come in this case */
975 up(&stcontext->exchange_lock);
976 goto free_skb_resp;
977 }
978
979 kfree_skb(skb);
980
981 return rc;
982
983free_skb_resp:
984 kfree_skb(skb_resp);
985 return rc;
986}
987
988/* p2p will be supported in a later release ! */
989static int st95hf_tg_configure_hw(struct nfc_digital_dev *ddev,
990 int type,
991 int param)
992{
993 return 0;
994}
995
996static int st95hf_tg_send_cmd(struct nfc_digital_dev *ddev,
997 struct sk_buff *skb,
998 u16 timeout,
999 nfc_digital_cmd_complete_t cb,
1000 void *arg)
1001{
1002 return 0;
1003}
1004
1005static int st95hf_tg_listen(struct nfc_digital_dev *ddev,
1006 u16 timeout,
1007 nfc_digital_cmd_complete_t cb,
1008 void *arg)
1009{
1010 return 0;
1011}
1012
1013static int st95hf_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1014{
1015 return 0;
1016}
1017
1018static int st95hf_switch_rf(struct nfc_digital_dev *ddev, bool on)
1019{
1020 u8 rf_tech;
1021 struct st95hf_context *stcontext = nfc_digital_get_drvdata(ddev);
1022
1023 rf_tech = ddev->curr_rf_tech;
1024
1025 if (on)
1026 /* switch on RF field */
1027 return st95hf_select_protocol(stcontext, rf_tech);
1028
1029 /* switch OFF RF field */
1030 return rf_off(stcontext);
1031}
1032
1033/* TODO st95hf_abort_cmd */
1034static void st95hf_abort_cmd(struct nfc_digital_dev *ddev)
1035{
1036}
1037
1038static const struct nfc_digital_ops st95hf_nfc_digital_ops = {
1039 .in_configure_hw = st95hf_in_configure_hw,
1040 .in_send_cmd = st95hf_in_send_cmd,
1041
1042 .tg_listen = st95hf_tg_listen,
1043 .tg_configure_hw = st95hf_tg_configure_hw,
1044 .tg_send_cmd = st95hf_tg_send_cmd,
1045 .tg_get_rf_tech = st95hf_tg_get_rf_tech,
1046
1047 .switch_rf = st95hf_switch_rf,
1048 .abort_cmd = st95hf_abort_cmd,
1049};
1050
1051static const struct spi_device_id st95hf_id[] = {
1052 { "st95hf", 0 },
1053 {}
1054};
1055MODULE_DEVICE_TABLE(spi, st95hf_id);
1056
1057static const struct of_device_id st95hf_spi_of_match[] __maybe_unused = {
1058 { .compatible = "st,st95hf" },
1059 {},
1060};
1061MODULE_DEVICE_TABLE(of, st95hf_spi_of_match);
1062
1063static int st95hf_probe(struct spi_device *nfc_spi_dev)
1064{
1065 struct device *dev = &nfc_spi_dev->dev;
1066 int ret;
1067
1068 struct st95hf_context *st95context;
1069 struct st95hf_spi_context *spicontext;
1070
1071 nfc_info(&nfc_spi_dev->dev, "ST95HF driver probe called.\n");
1072
1073 st95context = devm_kzalloc(&nfc_spi_dev->dev,
1074 sizeof(struct st95hf_context),
1075 GFP_KERNEL);
1076 if (!st95context)
1077 return -ENOMEM;
1078
1079 spicontext = &st95context->spicontext;
1080
1081 spicontext->spidev = nfc_spi_dev;
1082
1083 st95context->fwi =
1084 cmd_array[CMD_ISO14443A_PROTOCOL_SELECT].cmd_params[2];
1085
1086 if (device_property_present(&nfc_spi_dev->dev, "st95hfvin")) {
1087 st95context->st95hf_supply =
1088 devm_regulator_get(&nfc_spi_dev->dev,
1089 "st95hfvin");
1090 if (IS_ERR(st95context->st95hf_supply)) {
1091 dev_err(&nfc_spi_dev->dev, "failed to acquire regulator\n");
1092 return PTR_ERR(st95context->st95hf_supply);
1093 }
1094
1095 ret = regulator_enable(st95context->st95hf_supply);
1096 if (ret) {
1097 dev_err(&nfc_spi_dev->dev, "failed to enable regulator\n");
1098 return ret;
1099 }
1100 }
1101
1102 init_completion(&spicontext->done);
1103 mutex_init(&spicontext->spi_lock);
1104
1105 /*
1106 * Store spicontext in spi device object for using it in
1107 * remove function
1108 */
1109 dev_set_drvdata(&nfc_spi_dev->dev, spicontext);
1110
1111 st95context->enable_gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
1112 if (IS_ERR(st95context->enable_gpiod)) {
1113 ret = PTR_ERR(st95context->enable_gpiod);
1114 dev_err(&nfc_spi_dev->dev, "No valid enable gpio\n");
1115 goto err_disable_regulator;
1116 }
1117
1118 ret = gpiod_set_consumer_name(st95context->enable_gpiod, "enable_gpio");
1119 if (ret)
1120 goto err_disable_regulator;
1121
1122 if (nfc_spi_dev->irq > 0) {
1123 if (devm_request_threaded_irq(&nfc_spi_dev->dev,
1124 nfc_spi_dev->irq,
1125 st95hf_irq_handler,
1126 st95hf_irq_thread_handler,
1127 IRQF_TRIGGER_FALLING,
1128 "st95hf",
1129 (void *)st95context) < 0) {
1130 dev_err(&nfc_spi_dev->dev, "err: irq request for st95hf is failed\n");
1131 ret = -EINVAL;
1132 goto err_disable_regulator;
1133 }
1134 } else {
1135 dev_err(&nfc_spi_dev->dev, "not a valid IRQ associated with ST95HF\n");
1136 ret = -EINVAL;
1137 goto err_disable_regulator;
1138 }
1139
1140 /*
1141 * First reset SPI to handle warm reset of the system.
1142 * It will put the ST95HF device in Power ON state
1143 * which make the state of device identical to state
1144 * at the time of cold reset of the system.
1145 */
1146 ret = st95hf_send_spi_reset_sequence(st95context);
1147 if (ret) {
1148 dev_err(&nfc_spi_dev->dev, "err: spi_reset_sequence failed\n");
1149 goto err_disable_regulator;
1150 }
1151
1152 /* call PowerOnReset sequence of ST95hf to activate it */
1153 ret = st95hf_por_sequence(st95context);
1154 if (ret) {
1155 dev_err(&nfc_spi_dev->dev, "err: por seq failed for st95hf\n");
1156 goto err_disable_regulator;
1157 }
1158
1159 /* create NFC dev object and register with NFC Subsystem */
1160 st95context->ddev = nfc_digital_allocate_device(&st95hf_nfc_digital_ops,
1161 ST95HF_SUPPORTED_PROT,
1162 ST95HF_CAPABILITIES,
1163 ST95HF_HEADROOM_LEN,
1164 ST95HF_TAILROOM_LEN);
1165 if (!st95context->ddev) {
1166 ret = -ENOMEM;
1167 goto err_disable_regulator;
1168 }
1169
1170 st95context->nfcdev = st95context->ddev->nfc_dev;
1171 nfc_digital_set_parent_dev(st95context->ddev, &nfc_spi_dev->dev);
1172
1173 ret = nfc_digital_register_device(st95context->ddev);
1174 if (ret) {
1175 dev_err(&st95context->nfcdev->dev, "st95hf registration failed\n");
1176 goto err_free_digital_device;
1177 }
1178
1179 /* store st95context in nfc device object */
1180 nfc_digital_set_drvdata(st95context->ddev, st95context);
1181
1182 sema_init(&st95context->exchange_lock, 1);
1183 mutex_init(&st95context->rm_lock);
1184
1185 return ret;
1186
1187err_free_digital_device:
1188 nfc_digital_free_device(st95context->ddev);
1189err_disable_regulator:
1190 if (st95context->st95hf_supply)
1191 regulator_disable(st95context->st95hf_supply);
1192
1193 return ret;
1194}
1195
1196static void st95hf_remove(struct spi_device *nfc_spi_dev)
1197{
1198 int result = 0;
1199 unsigned char reset_cmd = ST95HF_COMMAND_RESET;
1200 struct st95hf_spi_context *spictx = dev_get_drvdata(&nfc_spi_dev->dev);
1201
1202 struct st95hf_context *stcontext = container_of(spictx,
1203 struct st95hf_context,
1204 spicontext);
1205
1206 mutex_lock(&stcontext->rm_lock);
1207
1208 nfc_digital_unregister_device(stcontext->ddev);
1209 nfc_digital_free_device(stcontext->ddev);
1210 stcontext->nfcdev_free = true;
1211
1212 mutex_unlock(&stcontext->rm_lock);
1213
1214 /* if last in_send_cmd's ISR is pending, wait for it to finish */
1215 result = down_killable(&stcontext->exchange_lock);
1216 if (result == -EINTR)
1217 dev_err(&spictx->spidev->dev, "sleep for semaphore interrupted by signal\n");
1218
1219 /* next reset the ST95HF controller */
1220 result = st95hf_spi_send(&stcontext->spicontext,
1221 &reset_cmd,
1222 ST95HF_RESET_CMD_LEN,
1223 ASYNC);
1224 if (result)
1225 dev_err(&spictx->spidev->dev,
1226 "ST95HF reset failed in remove() err = %d\n", result);
1227
1228 /* wait for 3 ms to complete the controller reset process */
1229 usleep_range(3000, 4000);
1230
1231 /* disable regulator */
1232 if (stcontext->st95hf_supply)
1233 regulator_disable(stcontext->st95hf_supply);
1234}
1235
1236/* Register as SPI protocol driver */
1237static struct spi_driver st95hf_driver = {
1238 .driver = {
1239 .name = "st95hf",
1240 .of_match_table = of_match_ptr(st95hf_spi_of_match),
1241 },
1242 .id_table = st95hf_id,
1243 .probe = st95hf_probe,
1244 .remove = st95hf_remove,
1245};
1246
1247module_spi_driver(st95hf_driver);
1248
1249MODULE_AUTHOR("Shikha Singh <shikha.singh@st.com>");
1250MODULE_DESCRIPTION("ST NFC Transceiver ST95HF driver");
1251MODULE_LICENSE("GPL v2");