1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2012 - 2018 Microchip Technology Inc., and its subsidiaries.
4  * All rights reserved.
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/spi/spi.h>
9 #include <linux/crc7.h>
10 #include <linux/crc-itu-t.h>
11 
12 #include "netdev.h"
13 #include "cfg80211.h"
14 
15 static bool enable_crc7;	/* protect SPI commands with CRC7 */
16 module_param(enable_crc7, bool, 0644);
17 MODULE_PARM_DESC(enable_crc7,
18 		 "Enable CRC7 checksum to protect command transfers\n"
19 		 "\t\t\tagainst corruption during the SPI transfer.\n"
20 		 "\t\t\tCommand transfers are short and the CPU-cycle cost\n"
21 		 "\t\t\tof enabling this is small.");
22 
23 static bool enable_crc16;	/* protect SPI data with CRC16 */
24 module_param(enable_crc16, bool, 0644);
25 MODULE_PARM_DESC(enable_crc16,
26 		 "Enable CRC16 checksum to protect data transfers\n"
27 		 "\t\t\tagainst corruption during the SPI transfer.\n"
28 		 "\t\t\tData transfers can be large and the CPU-cycle cost\n"
29 		 "\t\t\tof enabling this may be substantial.");
30 
31 /*
32  * For CMD_SINGLE_READ and CMD_INTERNAL_READ, WILC may insert one or
33  * more zero bytes between the command response and the DATA Start tag
34  * (0xf3).  This behavior appears to be undocumented in "ATWILC1000
35  * USER GUIDE" (https://tinyurl.com/4hhshdts) but we have observed 1-4
36  * zero bytes when the SPI bus operates at 48MHz and none when it
37  * operates at 1MHz.
38  */
39 #define WILC_SPI_RSP_HDR_EXTRA_DATA	8
40 
41 struct wilc_spi {
42 	bool isinit;		/* true if SPI protocol has been configured */
43 	bool probing_crc;	/* true if we're probing chip's CRC config */
44 	bool crc7_enabled;	/* true if crc7 is currently enabled */
45 	bool crc16_enabled;	/* true if crc16 is currently enabled */
46 };
47 
48 static const struct wilc_hif_func wilc_hif_spi;
49 
50 /********************************************
51  *
52  *      Spi protocol Function
53  *
54  ********************************************/
55 
56 #define CMD_DMA_WRITE				0xc1
57 #define CMD_DMA_READ				0xc2
58 #define CMD_INTERNAL_WRITE			0xc3
59 #define CMD_INTERNAL_READ			0xc4
60 #define CMD_TERMINATE				0xc5
61 #define CMD_REPEAT				0xc6
62 #define CMD_DMA_EXT_WRITE			0xc7
63 #define CMD_DMA_EXT_READ			0xc8
64 #define CMD_SINGLE_WRITE			0xc9
65 #define CMD_SINGLE_READ				0xca
66 #define CMD_RESET				0xcf
67 
68 #define SPI_ENABLE_VMM_RETRY_LIMIT		2
69 
70 /* SPI response fields (section 11.1.2 in ATWILC1000 User Guide): */
71 #define RSP_START_FIELD				GENMASK(7, 4)
72 #define RSP_TYPE_FIELD				GENMASK(3, 0)
73 
74 /* SPI response values for the response fields: */
75 #define RSP_START_TAG				0xc
76 #define RSP_TYPE_FIRST_PACKET			0x1
77 #define RSP_TYPE_INNER_PACKET			0x2
78 #define RSP_TYPE_LAST_PACKET			0x3
79 #define RSP_STATE_NO_ERROR			0x00
80 
81 #define PROTOCOL_REG_PKT_SZ_MASK		GENMASK(6, 4)
82 #define PROTOCOL_REG_CRC16_MASK			GENMASK(3, 3)
83 #define PROTOCOL_REG_CRC7_MASK			GENMASK(2, 2)
84 
85 /*
86  * The SPI data packet size may be any integer power of two in the
87  * range from 256 to 8192 bytes.
88  */
89 #define DATA_PKT_LOG_SZ_MIN			8	/* 256 B */
90 #define DATA_PKT_LOG_SZ_MAX			13	/* 8 KiB */
91 
92 /*
93  * Select the data packet size (log2 of number of bytes): Use the
94  * maximum data packet size.  We only retransmit complete packets, so
95  * there is no benefit from using smaller data packets.
96  */
97 #define DATA_PKT_LOG_SZ				DATA_PKT_LOG_SZ_MAX
98 #define DATA_PKT_SZ				(1 << DATA_PKT_LOG_SZ)
99 
100 #define USE_SPI_DMA				0
101 
102 #define WILC_SPI_COMMAND_STAT_SUCCESS		0
103 #define WILC_GET_RESP_HDR_START(h)		(((h) >> 4) & 0xf)
104 
105 struct wilc_spi_cmd {
106 	u8 cmd_type;
107 	union {
108 		struct {
109 			u8 addr[3];
110 			u8 crc[];
111 		} __packed simple_cmd;
112 		struct {
113 			u8 addr[3];
114 			u8 size[2];
115 			u8 crc[];
116 		} __packed dma_cmd;
117 		struct {
118 			u8 addr[3];
119 			u8 size[3];
120 			u8 crc[];
121 		} __packed dma_cmd_ext;
122 		struct {
123 			u8 addr[2];
124 			__be32 data;
125 			u8 crc[];
126 		} __packed internal_w_cmd;
127 		struct {
128 			u8 addr[3];
129 			__be32 data;
130 			u8 crc[];
131 		} __packed w_cmd;
132 	} u;
133 } __packed;
134 
135 struct wilc_spi_read_rsp_data {
136 	u8 header;
137 	u8 data[4];
138 	u8 crc[];
139 } __packed;
140 
141 struct wilc_spi_rsp_data {
142 	u8 rsp_cmd_type;
143 	u8 status;
144 	u8 data[];
145 } __packed;
146 
147 static int wilc_bus_probe(struct spi_device *spi)
148 {
149 	int ret;
150 	struct wilc *wilc;
151 	struct wilc_spi *spi_priv;
152 
153 	spi_priv = kzalloc(sizeof(*spi_priv), GFP_KERNEL);
154 	if (!spi_priv)
155 		return -ENOMEM;
156 
157 	ret = wilc_cfg80211_init(&wilc, &spi->dev, WILC_HIF_SPI, &wilc_hif_spi);
158 	if (ret)
159 		goto free;
160 
161 	spi_set_drvdata(spi, wilc);
162 	wilc->dev = &spi->dev;
163 	wilc->bus_data = spi_priv;
164 	wilc->dev_irq_num = spi->irq;
165 
166 	wilc->rtc_clk = devm_clk_get_optional(&spi->dev, "rtc");
167 	if (IS_ERR(wilc->rtc_clk)) {
168 		ret = PTR_ERR(wilc->rtc_clk);
169 		goto netdev_cleanup;
170 	}
171 	clk_prepare_enable(wilc->rtc_clk);
172 
173 	return 0;
174 
175 netdev_cleanup:
176 	wilc_netdev_cleanup(wilc);
177 free:
178 	kfree(spi_priv);
179 	return ret;
180 }
181 
182 static int wilc_bus_remove(struct spi_device *spi)
183 {
184 	struct wilc *wilc = spi_get_drvdata(spi);
185 
186 	clk_disable_unprepare(wilc->rtc_clk);
187 	wilc_netdev_cleanup(wilc);
188 
189 	return 0;
190 }
191 
192 static const struct of_device_id wilc_of_match[] = {
193 	{ .compatible = "microchip,wilc1000", },
194 	{ /* sentinel */ }
195 };
196 MODULE_DEVICE_TABLE(of, wilc_of_match);
197 
198 static struct spi_driver wilc_spi_driver = {
199 	.driver = {
200 		.name = MODALIAS,
201 		.of_match_table = wilc_of_match,
202 	},
203 	.probe =  wilc_bus_probe,
204 	.remove = wilc_bus_remove,
205 };
206 module_spi_driver(wilc_spi_driver);
207 MODULE_LICENSE("GPL");
208 
209 static int wilc_spi_tx(struct wilc *wilc, u8 *b, u32 len)
210 {
211 	struct spi_device *spi = to_spi_device(wilc->dev);
212 	int ret;
213 	struct spi_message msg;
214 
215 	if (len > 0 && b) {
216 		struct spi_transfer tr = {
217 			.tx_buf = b,
218 			.len = len,
219 			.delay = {
220 				.value = 0,
221 				.unit = SPI_DELAY_UNIT_USECS
222 			},
223 		};
224 		char *r_buffer = kzalloc(len, GFP_KERNEL);
225 
226 		if (!r_buffer)
227 			return -ENOMEM;
228 
229 		tr.rx_buf = r_buffer;
230 		dev_dbg(&spi->dev, "Request writing %d bytes\n", len);
231 
232 		memset(&msg, 0, sizeof(msg));
233 		spi_message_init(&msg);
234 		msg.spi = spi;
235 		msg.is_dma_mapped = USE_SPI_DMA;
236 		spi_message_add_tail(&tr, &msg);
237 
238 		ret = spi_sync(spi, &msg);
239 		if (ret < 0)
240 			dev_err(&spi->dev, "SPI transaction failed\n");
241 
242 		kfree(r_buffer);
243 	} else {
244 		dev_err(&spi->dev,
245 			"can't write data with the following length: %d\n",
246 			len);
247 		ret = -EINVAL;
248 	}
249 
250 	return ret;
251 }
252 
253 static int wilc_spi_rx(struct wilc *wilc, u8 *rb, u32 rlen)
254 {
255 	struct spi_device *spi = to_spi_device(wilc->dev);
256 	int ret;
257 
258 	if (rlen > 0) {
259 		struct spi_message msg;
260 		struct spi_transfer tr = {
261 			.rx_buf = rb,
262 			.len = rlen,
263 			.delay = {
264 				.value = 0,
265 				.unit = SPI_DELAY_UNIT_USECS
266 			},
267 
268 		};
269 		char *t_buffer = kzalloc(rlen, GFP_KERNEL);
270 
271 		if (!t_buffer)
272 			return -ENOMEM;
273 
274 		tr.tx_buf = t_buffer;
275 
276 		memset(&msg, 0, sizeof(msg));
277 		spi_message_init(&msg);
278 		msg.spi = spi;
279 		msg.is_dma_mapped = USE_SPI_DMA;
280 		spi_message_add_tail(&tr, &msg);
281 
282 		ret = spi_sync(spi, &msg);
283 		if (ret < 0)
284 			dev_err(&spi->dev, "SPI transaction failed\n");
285 		kfree(t_buffer);
286 	} else {
287 		dev_err(&spi->dev,
288 			"can't read data with the following length: %u\n",
289 			rlen);
290 		ret = -EINVAL;
291 	}
292 
293 	return ret;
294 }
295 
296 static int wilc_spi_tx_rx(struct wilc *wilc, u8 *wb, u8 *rb, u32 rlen)
297 {
298 	struct spi_device *spi = to_spi_device(wilc->dev);
299 	int ret;
300 
301 	if (rlen > 0) {
302 		struct spi_message msg;
303 		struct spi_transfer tr = {
304 			.rx_buf = rb,
305 			.tx_buf = wb,
306 			.len = rlen,
307 			.bits_per_word = 8,
308 			.delay = {
309 				.value = 0,
310 				.unit = SPI_DELAY_UNIT_USECS
311 			},
312 
313 		};
314 
315 		memset(&msg, 0, sizeof(msg));
316 		spi_message_init(&msg);
317 		msg.spi = spi;
318 		msg.is_dma_mapped = USE_SPI_DMA;
319 
320 		spi_message_add_tail(&tr, &msg);
321 		ret = spi_sync(spi, &msg);
322 		if (ret < 0)
323 			dev_err(&spi->dev, "SPI transaction failed\n");
324 	} else {
325 		dev_err(&spi->dev,
326 			"can't read data with the following length: %u\n",
327 			rlen);
328 		ret = -EINVAL;
329 	}
330 
331 	return ret;
332 }
333 
334 static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz)
335 {
336 	struct spi_device *spi = to_spi_device(wilc->dev);
337 	struct wilc_spi *spi_priv = wilc->bus_data;
338 	int ix, nbytes;
339 	int result = 0;
340 	u8 cmd, order, crc[2];
341 	u16 crc_calc;
342 
343 	/*
344 	 * Data
345 	 */
346 	ix = 0;
347 	do {
348 		if (sz <= DATA_PKT_SZ) {
349 			nbytes = sz;
350 			order = 0x3;
351 		} else {
352 			nbytes = DATA_PKT_SZ;
353 			if (ix == 0)
354 				order = 0x1;
355 			else
356 				order = 0x02;
357 		}
358 
359 		/*
360 		 * Write command
361 		 */
362 		cmd = 0xf0;
363 		cmd |= order;
364 
365 		if (wilc_spi_tx(wilc, &cmd, 1)) {
366 			dev_err(&spi->dev,
367 				"Failed data block cmd write, bus error...\n");
368 			result = -EINVAL;
369 			break;
370 		}
371 
372 		/*
373 		 * Write data
374 		 */
375 		if (wilc_spi_tx(wilc, &b[ix], nbytes)) {
376 			dev_err(&spi->dev,
377 				"Failed data block write, bus error...\n");
378 			result = -EINVAL;
379 			break;
380 		}
381 
382 		/*
383 		 * Write CRC
384 		 */
385 		if (spi_priv->crc16_enabled) {
386 			crc_calc = crc_itu_t(0xffff, &b[ix], nbytes);
387 			crc[0] = crc_calc >> 8;
388 			crc[1] = crc_calc;
389 			if (wilc_spi_tx(wilc, crc, 2)) {
390 				dev_err(&spi->dev, "Failed data block crc write, bus error...\n");
391 				result = -EINVAL;
392 				break;
393 			}
394 		}
395 
396 		/*
397 		 * No need to wait for response
398 		 */
399 		ix += nbytes;
400 		sz -= nbytes;
401 	} while (sz);
402 
403 	return result;
404 }
405 
406 /********************************************
407  *
408  *      Spi Internal Read/Write Function
409  *
410  ********************************************/
411 static u8 wilc_get_crc7(u8 *buffer, u32 len)
412 {
413 	return crc7_be(0xfe, buffer, len);
414 }
415 
416 static int wilc_spi_single_read(struct wilc *wilc, u8 cmd, u32 adr, void *b,
417 				u8 clockless)
418 {
419 	struct spi_device *spi = to_spi_device(wilc->dev);
420 	struct wilc_spi *spi_priv = wilc->bus_data;
421 	u8 wb[32], rb[32];
422 	int cmd_len, resp_len, i;
423 	u16 crc_calc, crc_recv;
424 	struct wilc_spi_cmd *c;
425 	struct wilc_spi_rsp_data *r;
426 	struct wilc_spi_read_rsp_data *r_data;
427 
428 	memset(wb, 0x0, sizeof(wb));
429 	memset(rb, 0x0, sizeof(rb));
430 	c = (struct wilc_spi_cmd *)wb;
431 	c->cmd_type = cmd;
432 	if (cmd == CMD_SINGLE_READ) {
433 		c->u.simple_cmd.addr[0] = adr >> 16;
434 		c->u.simple_cmd.addr[1] = adr >> 8;
435 		c->u.simple_cmd.addr[2] = adr;
436 	} else if (cmd == CMD_INTERNAL_READ) {
437 		c->u.simple_cmd.addr[0] = adr >> 8;
438 		if (clockless == 1)
439 			c->u.simple_cmd.addr[0] |= BIT(7);
440 		c->u.simple_cmd.addr[1] = adr;
441 		c->u.simple_cmd.addr[2] = 0x0;
442 	} else {
443 		dev_err(&spi->dev, "cmd [%x] not supported\n", cmd);
444 		return -EINVAL;
445 	}
446 
447 	cmd_len = offsetof(struct wilc_spi_cmd, u.simple_cmd.crc);
448 	resp_len = sizeof(*r) + sizeof(*r_data) + WILC_SPI_RSP_HDR_EXTRA_DATA;
449 
450 	if (spi_priv->crc7_enabled) {
451 		c->u.simple_cmd.crc[0] = wilc_get_crc7(wb, cmd_len);
452 		cmd_len += 1;
453 		resp_len += 2;
454 	}
455 
456 	if (cmd_len + resp_len > ARRAY_SIZE(wb)) {
457 		dev_err(&spi->dev,
458 			"spi buffer size too small (%d) (%d) (%zu)\n",
459 			cmd_len, resp_len, ARRAY_SIZE(wb));
460 		return -EINVAL;
461 	}
462 
463 	if (wilc_spi_tx_rx(wilc, wb, rb, cmd_len + resp_len)) {
464 		dev_err(&spi->dev, "Failed cmd write, bus error...\n");
465 		return -EINVAL;
466 	}
467 
468 	r = (struct wilc_spi_rsp_data *)&rb[cmd_len];
469 	if (r->rsp_cmd_type != cmd) {
470 		if (!spi_priv->probing_crc)
471 			dev_err(&spi->dev,
472 				"Failed cmd, cmd (%02x), resp (%02x)\n",
473 				cmd, r->rsp_cmd_type);
474 		return -EINVAL;
475 	}
476 
477 	if (r->status != WILC_SPI_COMMAND_STAT_SUCCESS) {
478 		dev_err(&spi->dev, "Failed cmd state response state (%02x)\n",
479 			r->status);
480 		return -EINVAL;
481 	}
482 
483 	for (i = 0; i < WILC_SPI_RSP_HDR_EXTRA_DATA; ++i)
484 		if (WILC_GET_RESP_HDR_START(r->data[i]) == 0xf)
485 			break;
486 
487 	if (i >= WILC_SPI_RSP_HDR_EXTRA_DATA) {
488 		dev_err(&spi->dev, "Error, data start missing\n");
489 		return -EINVAL;
490 	}
491 
492 	r_data = (struct wilc_spi_read_rsp_data *)&r->data[i];
493 
494 	if (b)
495 		memcpy(b, r_data->data, 4);
496 
497 	if (!clockless && spi_priv->crc16_enabled) {
498 		crc_recv = (r_data->crc[0] << 8) | r_data->crc[1];
499 		crc_calc = crc_itu_t(0xffff, r_data->data, 4);
500 		if (crc_recv != crc_calc) {
501 			dev_err(&spi->dev, "%s: bad CRC 0x%04x "
502 				"(calculated 0x%04x)\n", __func__,
503 				crc_recv, crc_calc);
504 			return -EINVAL;
505 		}
506 	}
507 
508 	return 0;
509 }
510 
511 static int wilc_spi_write_cmd(struct wilc *wilc, u8 cmd, u32 adr, u32 data,
512 			      u8 clockless)
513 {
514 	struct spi_device *spi = to_spi_device(wilc->dev);
515 	struct wilc_spi *spi_priv = wilc->bus_data;
516 	u8 wb[32], rb[32];
517 	int cmd_len, resp_len;
518 	struct wilc_spi_cmd *c;
519 	struct wilc_spi_rsp_data *r;
520 
521 	memset(wb, 0x0, sizeof(wb));
522 	memset(rb, 0x0, sizeof(rb));
523 	c = (struct wilc_spi_cmd *)wb;
524 	c->cmd_type = cmd;
525 	if (cmd == CMD_INTERNAL_WRITE) {
526 		c->u.internal_w_cmd.addr[0] = adr >> 8;
527 		if (clockless == 1)
528 			c->u.internal_w_cmd.addr[0] |= BIT(7);
529 
530 		c->u.internal_w_cmd.addr[1] = adr;
531 		c->u.internal_w_cmd.data = cpu_to_be32(data);
532 		cmd_len = offsetof(struct wilc_spi_cmd, u.internal_w_cmd.crc);
533 		if (spi_priv->crc7_enabled)
534 			c->u.internal_w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len);
535 	} else if (cmd == CMD_SINGLE_WRITE) {
536 		c->u.w_cmd.addr[0] = adr >> 16;
537 		c->u.w_cmd.addr[1] = adr >> 8;
538 		c->u.w_cmd.addr[2] = adr;
539 		c->u.w_cmd.data = cpu_to_be32(data);
540 		cmd_len = offsetof(struct wilc_spi_cmd, u.w_cmd.crc);
541 		if (spi_priv->crc7_enabled)
542 			c->u.w_cmd.crc[0] = wilc_get_crc7(wb, cmd_len);
543 	} else {
544 		dev_err(&spi->dev, "write cmd [%x] not supported\n", cmd);
545 		return -EINVAL;
546 	}
547 
548 	if (spi_priv->crc7_enabled)
549 		cmd_len += 1;
550 
551 	resp_len = sizeof(*r);
552 
553 	if (cmd_len + resp_len > ARRAY_SIZE(wb)) {
554 		dev_err(&spi->dev,
555 			"spi buffer size too small (%d) (%d) (%zu)\n",
556 			cmd_len, resp_len, ARRAY_SIZE(wb));
557 		return -EINVAL;
558 	}
559 
560 	if (wilc_spi_tx_rx(wilc, wb, rb, cmd_len + resp_len)) {
561 		dev_err(&spi->dev, "Failed cmd write, bus error...\n");
562 		return -EINVAL;
563 	}
564 
565 	r = (struct wilc_spi_rsp_data *)&rb[cmd_len];
566 	if (r->rsp_cmd_type != cmd) {
567 		dev_err(&spi->dev,
568 			"Failed cmd response, cmd (%02x), resp (%02x)\n",
569 			cmd, r->rsp_cmd_type);
570 		return -EINVAL;
571 	}
572 
573 	if (r->status != WILC_SPI_COMMAND_STAT_SUCCESS) {
574 		dev_err(&spi->dev, "Failed cmd state response state (%02x)\n",
575 			r->status);
576 		return -EINVAL;
577 	}
578 
579 	return 0;
580 }
581 
582 static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz)
583 {
584 	struct spi_device *spi = to_spi_device(wilc->dev);
585 	struct wilc_spi *spi_priv = wilc->bus_data;
586 	u16 crc_recv, crc_calc;
587 	u8 wb[32], rb[32];
588 	int cmd_len, resp_len;
589 	int retry, ix = 0;
590 	u8 crc[2];
591 	struct wilc_spi_cmd *c;
592 	struct wilc_spi_rsp_data *r;
593 
594 	memset(wb, 0x0, sizeof(wb));
595 	memset(rb, 0x0, sizeof(rb));
596 	c = (struct wilc_spi_cmd *)wb;
597 	c->cmd_type = cmd;
598 	if (cmd == CMD_DMA_WRITE || cmd == CMD_DMA_READ) {
599 		c->u.dma_cmd.addr[0] = adr >> 16;
600 		c->u.dma_cmd.addr[1] = adr >> 8;
601 		c->u.dma_cmd.addr[2] = adr;
602 		c->u.dma_cmd.size[0] = sz >> 8;
603 		c->u.dma_cmd.size[1] = sz;
604 		cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd.crc);
605 		if (spi_priv->crc7_enabled)
606 			c->u.dma_cmd.crc[0] = wilc_get_crc7(wb, cmd_len);
607 	} else if (cmd == CMD_DMA_EXT_WRITE || cmd == CMD_DMA_EXT_READ) {
608 		c->u.dma_cmd_ext.addr[0] = adr >> 16;
609 		c->u.dma_cmd_ext.addr[1] = adr >> 8;
610 		c->u.dma_cmd_ext.addr[2] = adr;
611 		c->u.dma_cmd_ext.size[0] = sz >> 16;
612 		c->u.dma_cmd_ext.size[1] = sz >> 8;
613 		c->u.dma_cmd_ext.size[2] = sz;
614 		cmd_len = offsetof(struct wilc_spi_cmd, u.dma_cmd_ext.crc);
615 		if (spi_priv->crc7_enabled)
616 			c->u.dma_cmd_ext.crc[0] = wilc_get_crc7(wb, cmd_len);
617 	} else {
618 		dev_err(&spi->dev, "dma read write cmd [%x] not supported\n",
619 			cmd);
620 		return -EINVAL;
621 	}
622 	if (spi_priv->crc7_enabled)
623 		cmd_len += 1;
624 
625 	resp_len = sizeof(*r);
626 
627 	if (cmd_len + resp_len > ARRAY_SIZE(wb)) {
628 		dev_err(&spi->dev, "spi buffer size too small (%d)(%d) (%zu)\n",
629 			cmd_len, resp_len, ARRAY_SIZE(wb));
630 		return -EINVAL;
631 	}
632 
633 	if (wilc_spi_tx_rx(wilc, wb, rb, cmd_len + resp_len)) {
634 		dev_err(&spi->dev, "Failed cmd write, bus error...\n");
635 		return -EINVAL;
636 	}
637 
638 	r = (struct wilc_spi_rsp_data *)&rb[cmd_len];
639 	if (r->rsp_cmd_type != cmd) {
640 		dev_err(&spi->dev,
641 			"Failed cmd response, cmd (%02x), resp (%02x)\n",
642 			cmd, r->rsp_cmd_type);
643 		return -EINVAL;
644 	}
645 
646 	if (r->status != WILC_SPI_COMMAND_STAT_SUCCESS) {
647 		dev_err(&spi->dev, "Failed cmd state response state (%02x)\n",
648 			r->status);
649 		return -EINVAL;
650 	}
651 
652 	if (cmd == CMD_DMA_WRITE || cmd == CMD_DMA_EXT_WRITE)
653 		return 0;
654 
655 	while (sz > 0) {
656 		int nbytes;
657 		u8 rsp;
658 
659 		if (sz <= DATA_PKT_SZ)
660 			nbytes = sz;
661 		else
662 			nbytes = DATA_PKT_SZ;
663 
664 		/*
665 		 * Data Response header
666 		 */
667 		retry = 100;
668 		do {
669 			if (wilc_spi_rx(wilc, &rsp, 1)) {
670 				dev_err(&spi->dev,
671 					"Failed resp read, bus err\n");
672 				return -EINVAL;
673 			}
674 			if (WILC_GET_RESP_HDR_START(rsp) == 0xf)
675 				break;
676 		} while (retry--);
677 
678 		/*
679 		 * Read bytes
680 		 */
681 		if (wilc_spi_rx(wilc, &b[ix], nbytes)) {
682 			dev_err(&spi->dev,
683 				"Failed block read, bus err\n");
684 			return -EINVAL;
685 		}
686 
687 		/*
688 		 * Read CRC
689 		 */
690 		if (spi_priv->crc16_enabled) {
691 			if (wilc_spi_rx(wilc, crc, 2)) {
692 				dev_err(&spi->dev,
693 					"Failed block CRC read, bus err\n");
694 				return -EINVAL;
695 			}
696 			crc_recv = (crc[0] << 8) | crc[1];
697 			crc_calc = crc_itu_t(0xffff, &b[ix], nbytes);
698 			if (crc_recv != crc_calc) {
699 				dev_err(&spi->dev, "%s: bad CRC 0x%04x "
700 					"(calculated 0x%04x)\n", __func__,
701 					crc_recv, crc_calc);
702 				return -EINVAL;
703 			}
704 		}
705 
706 		ix += nbytes;
707 		sz -= nbytes;
708 	}
709 	return 0;
710 }
711 
712 static int wilc_spi_read_reg(struct wilc *wilc, u32 addr, u32 *data)
713 {
714 	struct spi_device *spi = to_spi_device(wilc->dev);
715 	int result;
716 	u8 cmd = CMD_SINGLE_READ;
717 	u8 clockless = 0;
718 
719 	if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
720 		/* Clockless register */
721 		cmd = CMD_INTERNAL_READ;
722 		clockless = 1;
723 	}
724 
725 	result = wilc_spi_single_read(wilc, cmd, addr, data, clockless);
726 	if (result) {
727 		dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
728 		return result;
729 	}
730 
731 	le32_to_cpus(data);
732 
733 	return 0;
734 }
735 
736 static int wilc_spi_read(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
737 {
738 	struct spi_device *spi = to_spi_device(wilc->dev);
739 	int result;
740 
741 	if (size <= 4)
742 		return -EINVAL;
743 
744 	result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_READ, addr, buf, size);
745 	if (result) {
746 		dev_err(&spi->dev, "Failed cmd, read block (%08x)...\n", addr);
747 		return result;
748 	}
749 
750 	return 0;
751 }
752 
753 static int spi_internal_write(struct wilc *wilc, u32 adr, u32 dat)
754 {
755 	struct spi_device *spi = to_spi_device(wilc->dev);
756 	int result;
757 
758 	result = wilc_spi_write_cmd(wilc, CMD_INTERNAL_WRITE, adr, dat, 0);
759 	if (result) {
760 		dev_err(&spi->dev, "Failed internal write cmd...\n");
761 		return result;
762 	}
763 
764 	return 0;
765 }
766 
767 static int spi_internal_read(struct wilc *wilc, u32 adr, u32 *data)
768 {
769 	struct spi_device *spi = to_spi_device(wilc->dev);
770 	struct wilc_spi *spi_priv = wilc->bus_data;
771 	int result;
772 
773 	result = wilc_spi_single_read(wilc, CMD_INTERNAL_READ, adr, data, 0);
774 	if (result) {
775 		if (!spi_priv->probing_crc)
776 			dev_err(&spi->dev, "Failed internal read cmd...\n");
777 		return result;
778 	}
779 
780 	le32_to_cpus(data);
781 
782 	return 0;
783 }
784 
785 /********************************************
786  *
787  *      Spi interfaces
788  *
789  ********************************************/
790 
791 static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data)
792 {
793 	struct spi_device *spi = to_spi_device(wilc->dev);
794 	int result;
795 	u8 cmd = CMD_SINGLE_WRITE;
796 	u8 clockless = 0;
797 
798 	if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
799 		/* Clockless register */
800 		cmd = CMD_INTERNAL_WRITE;
801 		clockless = 1;
802 	}
803 
804 	result = wilc_spi_write_cmd(wilc, cmd, addr, data, clockless);
805 	if (result) {
806 		dev_err(&spi->dev, "Failed cmd, write reg (%08x)...\n", addr);
807 		return result;
808 	}
809 
810 	return 0;
811 }
812 
813 static int spi_data_rsp(struct wilc *wilc, u8 cmd)
814 {
815 	struct spi_device *spi = to_spi_device(wilc->dev);
816 	int result, i;
817 	u8 rsp[4];
818 
819 	/*
820 	 * The response to data packets is two bytes long.  For
821 	 * efficiency's sake, wilc_spi_write() wisely ignores the
822 	 * responses for all packets but the final one.  The downside
823 	 * of that optimization is that when the final data packet is
824 	 * short, we may receive (part of) the response to the
825 	 * second-to-last packet before the one for the final packet.
826 	 * To handle this, we always read 4 bytes and then search for
827 	 * the last byte that contains the "Response Start" code (0xc
828 	 * in the top 4 bits).  We then know that this byte is the
829 	 * first response byte of the final data packet.
830 	 */
831 	result = wilc_spi_rx(wilc, rsp, sizeof(rsp));
832 	if (result) {
833 		dev_err(&spi->dev, "Failed bus error...\n");
834 		return result;
835 	}
836 
837 	for (i = sizeof(rsp) - 2; i >= 0; --i)
838 		if (FIELD_GET(RSP_START_FIELD, rsp[i]) == RSP_START_TAG)
839 			break;
840 
841 	if (i < 0) {
842 		dev_err(&spi->dev,
843 			"Data packet response missing (%02x %02x %02x %02x)\n",
844 			rsp[0], rsp[1], rsp[2], rsp[3]);
845 		return -1;
846 	}
847 
848 	/* rsp[i] is the last response start byte */
849 
850 	if (FIELD_GET(RSP_TYPE_FIELD, rsp[i]) != RSP_TYPE_LAST_PACKET
851 	    || rsp[i + 1] != RSP_STATE_NO_ERROR) {
852 		dev_err(&spi->dev, "Data response error (%02x %02x)\n",
853 			rsp[i], rsp[i + 1]);
854 		return -1;
855 	}
856 	return 0;
857 }
858 
859 static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
860 {
861 	struct spi_device *spi = to_spi_device(wilc->dev);
862 	int result;
863 
864 	/*
865 	 * has to be greated than 4
866 	 */
867 	if (size <= 4)
868 		return -EINVAL;
869 
870 	result = wilc_spi_dma_rw(wilc, CMD_DMA_EXT_WRITE, addr, NULL, size);
871 	if (result) {
872 		dev_err(&spi->dev,
873 			"Failed cmd, write block (%08x)...\n", addr);
874 		return result;
875 	}
876 
877 	/*
878 	 * Data
879 	 */
880 	result = spi_data_write(wilc, buf, size);
881 	if (result) {
882 		dev_err(&spi->dev, "Failed block data write...\n");
883 		return result;
884 	}
885 
886 	/*
887 	 * Data response
888 	 */
889 	return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
890 }
891 
892 /********************************************
893  *
894  *      Bus interfaces
895  *
896  ********************************************/
897 
898 static int wilc_spi_deinit(struct wilc *wilc)
899 {
900 	/*
901 	 * TODO:
902 	 */
903 	return 0;
904 }
905 
906 static int wilc_spi_init(struct wilc *wilc, bool resume)
907 {
908 	struct spi_device *spi = to_spi_device(wilc->dev);
909 	struct wilc_spi *spi_priv = wilc->bus_data;
910 	u32 reg;
911 	u32 chipid;
912 	int ret, i;
913 
914 	if (spi_priv->isinit) {
915 		/* Confirm we can read chipid register without error: */
916 		ret = wilc_spi_read_reg(wilc, WILC_CHIPID, &chipid);
917 		if (ret == 0)
918 			return 0;
919 
920 		dev_err(&spi->dev, "Fail cmd read chip id...\n");
921 	}
922 
923 	/*
924 	 * configure protocol
925 	 */
926 
927 	/*
928 	 * Infer the CRC settings that are currently in effect.  This
929 	 * is necessary because we can't be sure that the chip has
930 	 * been RESET (e.g, after module unload and reload).
931 	 */
932 	spi_priv->probing_crc = true;
933 	spi_priv->crc7_enabled = enable_crc7;
934 	spi_priv->crc16_enabled = false; /* don't check CRC16 during probing */
935 	for (i = 0; i < 2; ++i) {
936 		ret = spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, &reg);
937 		if (ret == 0)
938 			break;
939 		spi_priv->crc7_enabled = !enable_crc7;
940 	}
941 	if (ret) {
942 		dev_err(&spi->dev, "Failed with CRC7 on and off.\n");
943 		return ret;
944 	}
945 
946 	/* set up the desired CRC configuration: */
947 	reg &= ~(PROTOCOL_REG_CRC7_MASK | PROTOCOL_REG_CRC16_MASK);
948 	if (enable_crc7)
949 		reg |= PROTOCOL_REG_CRC7_MASK;
950 	if (enable_crc16)
951 		reg |= PROTOCOL_REG_CRC16_MASK;
952 
953 	/* set up the data packet size: */
954 	BUILD_BUG_ON(DATA_PKT_LOG_SZ < DATA_PKT_LOG_SZ_MIN
955 		     || DATA_PKT_LOG_SZ > DATA_PKT_LOG_SZ_MAX);
956 	reg &= ~PROTOCOL_REG_PKT_SZ_MASK;
957 	reg |= FIELD_PREP(PROTOCOL_REG_PKT_SZ_MASK,
958 			  DATA_PKT_LOG_SZ - DATA_PKT_LOG_SZ_MIN);
959 
960 	/* establish the new setup: */
961 	ret = spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg);
962 	if (ret) {
963 		dev_err(&spi->dev,
964 			"[wilc spi %d]: Failed internal write reg\n",
965 			__LINE__);
966 		return ret;
967 	}
968 	/* update our state to match new protocol settings: */
969 	spi_priv->crc7_enabled = enable_crc7;
970 	spi_priv->crc16_enabled = enable_crc16;
971 
972 	/* re-read to make sure new settings are in effect: */
973 	spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, &reg);
974 
975 	spi_priv->probing_crc = false;
976 
977 	/*
978 	 * make sure can read chip id without protocol error
979 	 */
980 	ret = wilc_spi_read_reg(wilc, WILC_CHIPID, &chipid);
981 	if (ret) {
982 		dev_err(&spi->dev, "Fail cmd read chip id...\n");
983 		return ret;
984 	}
985 
986 	spi_priv->isinit = true;
987 
988 	return 0;
989 }
990 
991 static int wilc_spi_read_size(struct wilc *wilc, u32 *size)
992 {
993 	int ret;
994 
995 	ret = spi_internal_read(wilc,
996 				WILC_SPI_INT_STATUS - WILC_SPI_REG_BASE, size);
997 	*size = FIELD_GET(IRQ_DMA_WD_CNT_MASK, *size);
998 
999 	return ret;
1000 }
1001 
1002 static int wilc_spi_read_int(struct wilc *wilc, u32 *int_status)
1003 {
1004 	return spi_internal_read(wilc, WILC_SPI_INT_STATUS - WILC_SPI_REG_BASE,
1005 				 int_status);
1006 }
1007 
1008 static int wilc_spi_clear_int_ext(struct wilc *wilc, u32 val)
1009 {
1010 	int ret;
1011 	int retry = SPI_ENABLE_VMM_RETRY_LIMIT;
1012 	u32 check;
1013 
1014 	while (retry) {
1015 		ret = spi_internal_write(wilc,
1016 					 WILC_SPI_INT_CLEAR - WILC_SPI_REG_BASE,
1017 					 val);
1018 		if (ret)
1019 			break;
1020 
1021 		ret = spi_internal_read(wilc,
1022 					WILC_SPI_INT_CLEAR - WILC_SPI_REG_BASE,
1023 					&check);
1024 		if (ret || ((check & EN_VMM) == (val & EN_VMM)))
1025 			break;
1026 
1027 		retry--;
1028 	}
1029 	return ret;
1030 }
1031 
1032 static int wilc_spi_sync_ext(struct wilc *wilc, int nint)
1033 {
1034 	struct spi_device *spi = to_spi_device(wilc->dev);
1035 	u32 reg;
1036 	int ret, i;
1037 
1038 	if (nint > MAX_NUM_INT) {
1039 		dev_err(&spi->dev, "Too many interrupts (%d)...\n", nint);
1040 		return -EINVAL;
1041 	}
1042 
1043 	/*
1044 	 * interrupt pin mux select
1045 	 */
1046 	ret = wilc_spi_read_reg(wilc, WILC_PIN_MUX_0, &reg);
1047 	if (ret) {
1048 		dev_err(&spi->dev, "Failed read reg (%08x)...\n",
1049 			WILC_PIN_MUX_0);
1050 		return ret;
1051 	}
1052 	reg |= BIT(8);
1053 	ret = wilc_spi_write_reg(wilc, WILC_PIN_MUX_0, reg);
1054 	if (ret) {
1055 		dev_err(&spi->dev, "Failed write reg (%08x)...\n",
1056 			WILC_PIN_MUX_0);
1057 		return ret;
1058 	}
1059 
1060 	/*
1061 	 * interrupt enable
1062 	 */
1063 	ret = wilc_spi_read_reg(wilc, WILC_INTR_ENABLE, &reg);
1064 	if (ret) {
1065 		dev_err(&spi->dev, "Failed read reg (%08x)...\n",
1066 			WILC_INTR_ENABLE);
1067 		return ret;
1068 	}
1069 
1070 	for (i = 0; (i < 5) && (nint > 0); i++, nint--)
1071 		reg |= (BIT((27 + i)));
1072 
1073 	ret = wilc_spi_write_reg(wilc, WILC_INTR_ENABLE, reg);
1074 	if (ret) {
1075 		dev_err(&spi->dev, "Failed write reg (%08x)...\n",
1076 			WILC_INTR_ENABLE);
1077 		return ret;
1078 	}
1079 	if (nint) {
1080 		ret = wilc_spi_read_reg(wilc, WILC_INTR2_ENABLE, &reg);
1081 		if (ret) {
1082 			dev_err(&spi->dev, "Failed read reg (%08x)...\n",
1083 				WILC_INTR2_ENABLE);
1084 			return ret;
1085 		}
1086 
1087 		for (i = 0; (i < 3) && (nint > 0); i++, nint--)
1088 			reg |= BIT(i);
1089 
1090 		ret = wilc_spi_read_reg(wilc, WILC_INTR2_ENABLE, &reg);
1091 		if (ret) {
1092 			dev_err(&spi->dev, "Failed write reg (%08x)...\n",
1093 				WILC_INTR2_ENABLE);
1094 			return ret;
1095 		}
1096 	}
1097 
1098 	return 0;
1099 }
1100 
1101 /* Global spi HIF function table */
1102 static const struct wilc_hif_func wilc_hif_spi = {
1103 	.hif_init = wilc_spi_init,
1104 	.hif_deinit = wilc_spi_deinit,
1105 	.hif_read_reg = wilc_spi_read_reg,
1106 	.hif_write_reg = wilc_spi_write_reg,
1107 	.hif_block_rx = wilc_spi_read,
1108 	.hif_block_tx = wilc_spi_write,
1109 	.hif_read_int = wilc_spi_read_int,
1110 	.hif_clear_int_ext = wilc_spi_clear_int_ext,
1111 	.hif_read_size = wilc_spi_read_size,
1112 	.hif_block_tx_ext = wilc_spi_write,
1113 	.hif_block_rx_ext = wilc_spi_read,
1114 	.hif_sync_ext = wilc_spi_sync_ext,
1115 };
1116