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