Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
/*
 * Copyright (c) 2010 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*******************************************************************************
 * Communicates with the dongle by using dcmd codes.
 * For certain dcmd codes, the dongle interprets string data from the host.
 ******************************************************************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/netdevice.h>
#include <linux/sched.h>
#include <defs.h>

#include <brcmu_utils.h>
#include <brcmu_wifi.h>

#include "dhd.h"
#include "dhd_proto.h"
#include "dhd_bus.h"
#include "dhd_dbg.h"

struct brcmf_proto_cdc_dcmd {
	__le32 cmd;	/* dongle command value */
	__le32 len;	/* lower 16: output buflen;
			 * upper 16: input buflen (excludes header) */
	__le32 flags;	/* flag defns given below */
	__le32 status;	/* status code returned from the device */
};

/* Max valid buffer size that can be sent to the dongle */
#define CDC_MAX_MSG_SIZE	(ETH_FRAME_LEN+ETH_FCS_LEN)

/* CDC flag definitions */
#define CDC_DCMD_ERROR		0x01	/* 1=cmd failed */
#define CDC_DCMD_SET		0x02	/* 0=get, 1=set cmd */
#define CDC_DCMD_IF_MASK	0xF000		/* I/F index */
#define CDC_DCMD_IF_SHIFT	12
#define CDC_DCMD_ID_MASK	0xFFFF0000	/* id an cmd pairing */
#define CDC_DCMD_ID_SHIFT	16		/* ID Mask shift bits */
#define CDC_DCMD_ID(flags)	\
	(((flags) & CDC_DCMD_ID_MASK) >> CDC_DCMD_ID_SHIFT)

/*
 * BDC header - Broadcom specific extension of CDC.
 * Used on data packets to convey priority across USB.
 */
#define	BDC_HEADER_LEN		4
#define BDC_PROTO_VER		2	/* Protocol version */
#define BDC_FLAG_VER_MASK	0xf0	/* Protocol version mask */
#define BDC_FLAG_VER_SHIFT	4	/* Protocol version shift */
#define BDC_FLAG_SUM_GOOD	0x04	/* Good RX checksums */
#define BDC_FLAG_SUM_NEEDED	0x08	/* Dongle needs to do TX checksums */
#define BDC_PRIORITY_MASK	0x7
#define BDC_FLAG2_IF_MASK	0x0f	/* packet rx interface in APSTA */
#define BDC_FLAG2_IF_SHIFT	0

#define BDC_GET_IF_IDX(hdr) \
	((int)((((hdr)->flags2) & BDC_FLAG2_IF_MASK) >> BDC_FLAG2_IF_SHIFT))
#define BDC_SET_IF_IDX(hdr, idx) \
	((hdr)->flags2 = (((hdr)->flags2 & ~BDC_FLAG2_IF_MASK) | \
	((idx) << BDC_FLAG2_IF_SHIFT)))

struct brcmf_proto_bdc_header {
	u8 flags;
	u8 priority;	/* 802.1d Priority, 4:7 flow control info for usb */
	u8 flags2;
	u8 data_offset;
};


#define RETRIES 2 /* # of retries to retrieve matching dcmd response */
#define BUS_HEADER_LEN	(16+64)		/* Must be atleast SDPCM_RESERVE
					 * (amount of header tha might be added)
					 * plus any space that might be needed
					 * for bus alignment padding.
					 */
#define ROUND_UP_MARGIN	2048	/* Biggest bus block size possible for
				 * round off at the end of buffer
				 * Currently is SDIO
				 */

struct brcmf_proto {
	u16 reqid;
	u8 pending;
	u32 lastcmd;
	u8 bus_header[BUS_HEADER_LEN];
	struct brcmf_proto_cdc_dcmd msg;
	unsigned char buf[BRCMF_DCMD_MAXLEN + ROUND_UP_MARGIN];
};

static int brcmf_proto_cdc_msg(struct brcmf_pub *drvr)
{
	struct brcmf_proto *prot = drvr->prot;
	int len = le32_to_cpu(prot->msg.len) +
			sizeof(struct brcmf_proto_cdc_dcmd);

	brcmf_dbg(TRACE, "Enter\n");

	/* NOTE : cdc->msg.len holds the desired length of the buffer to be
	 *        returned. Only up to CDC_MAX_MSG_SIZE of this buffer area
	 *        is actually sent to the dongle
	 */
	if (len > CDC_MAX_MSG_SIZE)
		len = CDC_MAX_MSG_SIZE;

	/* Send request */
	return drvr->bus_if->brcmf_bus_txctl(drvr->dev,
					     (unsigned char *)&prot->msg,
					     len);
}

static int brcmf_proto_cdc_cmplt(struct brcmf_pub *drvr, u32 id, u32 len)
{
	int ret;
	struct brcmf_proto *prot = drvr->prot;

	brcmf_dbg(TRACE, "Enter\n");

	do {
		ret = drvr->bus_if->brcmf_bus_rxctl(drvr->dev,
				(unsigned char *)&prot->msg,
				len + sizeof(struct brcmf_proto_cdc_dcmd));
		if (ret < 0)
			break;
	} while (CDC_DCMD_ID(le32_to_cpu(prot->msg.flags)) != id);

	return ret;
}

int
brcmf_proto_cdc_query_dcmd(struct brcmf_pub *drvr, int ifidx, uint cmd,
			       void *buf, uint len)
{
	struct brcmf_proto *prot = drvr->prot;
	struct brcmf_proto_cdc_dcmd *msg = &prot->msg;
	void *info;
	int ret = 0, retries = 0;
	u32 id, flags;

	brcmf_dbg(TRACE, "Enter\n");
	brcmf_dbg(CTL, "cmd %d len %d\n", cmd, len);

	/* Respond "bcmerror" and "bcmerrorstr" with local cache */
	if (cmd == BRCMF_C_GET_VAR && buf) {
		if (!strcmp((char *)buf, "bcmerrorstr")) {
			strncpy((char *)buf, "bcm_error",
				BCME_STRLEN);
			goto done;
		} else if (!strcmp((char *)buf, "bcmerror")) {
			*(int *)buf = drvr->dongle_error;
			goto done;
		}
	}

	memset(msg, 0, sizeof(struct brcmf_proto_cdc_dcmd));

	msg->cmd = cpu_to_le32(cmd);
	msg->len = cpu_to_le32(len);
	flags = (++prot->reqid << CDC_DCMD_ID_SHIFT);
	flags = (flags & ~CDC_DCMD_IF_MASK) |
		(ifidx << CDC_DCMD_IF_SHIFT);
	msg->flags = cpu_to_le32(flags);

	if (buf)
		memcpy(prot->buf, buf, len);

	ret = brcmf_proto_cdc_msg(drvr);
	if (ret < 0) {
		brcmf_dbg(ERROR, "brcmf_proto_cdc_msg failed w/status %d\n",
			  ret);
		goto done;
	}

retry:
	/* wait for interrupt and get first fragment */
	ret = brcmf_proto_cdc_cmplt(drvr, prot->reqid, len);
	if (ret < 0)
		goto done;

	flags = le32_to_cpu(msg->flags);
	id = (flags & CDC_DCMD_ID_MASK) >> CDC_DCMD_ID_SHIFT;

	if ((id < prot->reqid) && (++retries < RETRIES))
		goto retry;
	if (id != prot->reqid) {
		brcmf_dbg(ERROR, "%s: unexpected request id %d (expected %d)\n",
			  brcmf_ifname(drvr, ifidx), id, prot->reqid);
		ret = -EINVAL;
		goto done;
	}

	/* Check info buffer */
	info = (void *)&msg[1];

	/* Copy info buffer */
	if (buf) {
		if (ret < (int)len)
			len = ret;
		memcpy(buf, info, len);
	}

	/* Check the ERROR flag */
	if (flags & CDC_DCMD_ERROR) {
		ret = le32_to_cpu(msg->status);
		/* Cache error from dongle */
		drvr->dongle_error = ret;
	}

done:
	return ret;
}

int brcmf_proto_cdc_set_dcmd(struct brcmf_pub *drvr, int ifidx, uint cmd,
				 void *buf, uint len)
{
	struct brcmf_proto *prot = drvr->prot;
	struct brcmf_proto_cdc_dcmd *msg = &prot->msg;
	int ret = 0;
	u32 flags, id;

	brcmf_dbg(TRACE, "Enter\n");
	brcmf_dbg(CTL, "cmd %d len %d\n", cmd, len);

	memset(msg, 0, sizeof(struct brcmf_proto_cdc_dcmd));

	msg->cmd = cpu_to_le32(cmd);
	msg->len = cpu_to_le32(len);
	flags = (++prot->reqid << CDC_DCMD_ID_SHIFT) | CDC_DCMD_SET;
	flags = (flags & ~CDC_DCMD_IF_MASK) |
		(ifidx << CDC_DCMD_IF_SHIFT);
	msg->flags = cpu_to_le32(flags);

	if (buf)
		memcpy(prot->buf, buf, len);

	ret = brcmf_proto_cdc_msg(drvr);
	if (ret < 0)
		goto done;

	ret = brcmf_proto_cdc_cmplt(drvr, prot->reqid, len);
	if (ret < 0)
		goto done;

	flags = le32_to_cpu(msg->flags);
	id = (flags & CDC_DCMD_ID_MASK) >> CDC_DCMD_ID_SHIFT;

	if (id != prot->reqid) {
		brcmf_dbg(ERROR, "%s: unexpected request id %d (expected %d)\n",
			  brcmf_ifname(drvr, ifidx), id, prot->reqid);
		ret = -EINVAL;
		goto done;
	}

	/* Check the ERROR flag */
	if (flags & CDC_DCMD_ERROR) {
		ret = le32_to_cpu(msg->status);
		/* Cache error from dongle */
		drvr->dongle_error = ret;
	}

done:
	return ret;
}

int
brcmf_proto_dcmd(struct brcmf_pub *drvr, int ifidx, struct brcmf_dcmd *dcmd,
		  int len)
{
	struct brcmf_proto *prot = drvr->prot;
	int ret = -1;

	if (drvr->bus_if->state == BRCMF_BUS_DOWN) {
		brcmf_dbg(ERROR, "bus is down. we have nothing to do.\n");
		return ret;
	}
	mutex_lock(&drvr->proto_block);

	brcmf_dbg(TRACE, "Enter\n");

	if (len > BRCMF_DCMD_MAXLEN)
		goto done;

	if (prot->pending == true) {
		brcmf_dbg(TRACE, "CDC packet is pending!!!! cmd=0x%x (%lu) lastcmd=0x%x (%lu)\n",
			  dcmd->cmd, (unsigned long)dcmd->cmd, prot->lastcmd,
			  (unsigned long)prot->lastcmd);
		if (dcmd->cmd == BRCMF_C_SET_VAR ||
		    dcmd->cmd == BRCMF_C_GET_VAR)
			brcmf_dbg(TRACE, "iovar cmd=%s\n", (char *)dcmd->buf);

		goto done;
	}

	prot->pending = true;
	prot->lastcmd = dcmd->cmd;
	if (dcmd->set)
		ret = brcmf_proto_cdc_set_dcmd(drvr, ifidx, dcmd->cmd,
						   dcmd->buf, len);
	else {
		ret = brcmf_proto_cdc_query_dcmd(drvr, ifidx, dcmd->cmd,
						     dcmd->buf, len);
		if (ret > 0)
			dcmd->used = ret -
					sizeof(struct brcmf_proto_cdc_dcmd);
	}

	if (ret >= 0)
		ret = 0;
	else {
		struct brcmf_proto_cdc_dcmd *msg = &prot->msg;
		/* len == needed when set/query fails from dongle */
		dcmd->needed = le32_to_cpu(msg->len);
	}

	/* Intercept the wme_dp dongle cmd here */
	if (!ret && dcmd->cmd == BRCMF_C_SET_VAR &&
	    !strcmp(dcmd->buf, "wme_dp")) {
		int slen;
		__le32 val = 0;

		slen = strlen("wme_dp") + 1;
		if (len >= (int)(slen + sizeof(int)))
			memcpy(&val, (char *)dcmd->buf + slen, sizeof(int));
		drvr->wme_dp = (u8) le32_to_cpu(val);
	}

	prot->pending = false;

done:
	mutex_unlock(&drvr->proto_block);

	return ret;
}

static bool pkt_sum_needed(struct sk_buff *skb)
{
	return skb->ip_summed == CHECKSUM_PARTIAL;
}

static void pkt_set_sum_good(struct sk_buff *skb, bool x)
{
	skb->ip_summed = (x ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
}

void brcmf_proto_hdrpush(struct brcmf_pub *drvr, int ifidx,
			 struct sk_buff *pktbuf)
{
	struct brcmf_proto_bdc_header *h;

	brcmf_dbg(TRACE, "Enter\n");

	/* Push BDC header used to convey priority for buses that don't */

	skb_push(pktbuf, BDC_HEADER_LEN);

	h = (struct brcmf_proto_bdc_header *)(pktbuf->data);

	h->flags = (BDC_PROTO_VER << BDC_FLAG_VER_SHIFT);
	if (pkt_sum_needed(pktbuf))
		h->flags |= BDC_FLAG_SUM_NEEDED;

	h->priority = (pktbuf->priority & BDC_PRIORITY_MASK);
	h->flags2 = 0;
	h->data_offset = 0;
	BDC_SET_IF_IDX(h, ifidx);
}

int brcmf_proto_hdrpull(struct device *dev, int *ifidx,
			struct sk_buff *pktbuf)
{
	struct brcmf_proto_bdc_header *h;
	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
	struct brcmf_pub *drvr = bus_if->drvr;

	brcmf_dbg(TRACE, "Enter\n");

	/* Pop BDC header used to convey priority for buses that don't */

	if (pktbuf->len < BDC_HEADER_LEN) {
		brcmf_dbg(ERROR, "rx data too short (%d < %d)\n",
			  pktbuf->len, BDC_HEADER_LEN);
		return -EBADE;
	}

	h = (struct brcmf_proto_bdc_header *)(pktbuf->data);

	*ifidx = BDC_GET_IF_IDX(h);
	if (*ifidx >= BRCMF_MAX_IFS) {
		brcmf_dbg(ERROR, "rx data ifnum out of range (%d)\n", *ifidx);
		return -EBADE;
	}

	if (((h->flags & BDC_FLAG_VER_MASK) >> BDC_FLAG_VER_SHIFT) !=
	    BDC_PROTO_VER) {
		brcmf_dbg(ERROR, "%s: non-BDC packet received, flags 0x%x\n",
			  brcmf_ifname(drvr, *ifidx), h->flags);
		return -EBADE;
	}

	if (h->flags & BDC_FLAG_SUM_GOOD) {
		brcmf_dbg(INFO, "%s: BDC packet received with good rx-csum, flags 0x%x\n",
			  brcmf_ifname(drvr, *ifidx), h->flags);
		pkt_set_sum_good(pktbuf, true);
	}

	pktbuf->priority = h->priority & BDC_PRIORITY_MASK;

	skb_pull(pktbuf, BDC_HEADER_LEN);

	return 0;
}

int brcmf_proto_attach(struct brcmf_pub *drvr)
{
	struct brcmf_proto *cdc;

	cdc = kzalloc(sizeof(struct brcmf_proto), GFP_ATOMIC);
	if (!cdc)
		goto fail;

	/* ensure that the msg buf directly follows the cdc msg struct */
	if ((unsigned long)(&cdc->msg + 1) != (unsigned long)cdc->buf) {
		brcmf_dbg(ERROR, "struct brcmf_proto is not correctly defined\n");
		goto fail;
	}

	drvr->prot = cdc;
	drvr->hdrlen += BDC_HEADER_LEN;
	drvr->bus_if->maxctl = BRCMF_DCMD_MAXLEN +
			sizeof(struct brcmf_proto_cdc_dcmd) + ROUND_UP_MARGIN;
	return 0;

fail:
	kfree(cdc);
	return -ENOMEM;
}

/* ~NOTE~ What if another thread is waiting on the semaphore?  Holding it? */
void brcmf_proto_detach(struct brcmf_pub *drvr)
{
	kfree(drvr->prot);
	drvr->prot = NULL;
}

int brcmf_proto_init(struct brcmf_pub *drvr)
{
	int ret = 0;
	char buf[128];

	brcmf_dbg(TRACE, "Enter\n");

	mutex_lock(&drvr->proto_block);

	/* Get the device MAC address */
	strcpy(buf, "cur_etheraddr");
	ret = brcmf_proto_cdc_query_dcmd(drvr, 0, BRCMF_C_GET_VAR,
					  buf, sizeof(buf));
	if (ret < 0) {
		mutex_unlock(&drvr->proto_block);
		return ret;
	}
	memcpy(drvr->mac, buf, ETH_ALEN);

	mutex_unlock(&drvr->proto_block);

	ret = brcmf_c_preinit_dcmds(drvr);

	/* Always assumes wl for now */
	drvr->iswl = true;

	return ret;
}

void brcmf_proto_stop(struct brcmf_pub *drvr)
{
	/* Nothing to do for CDC */
}