1/*
2 * Cryptographic API.
3 *
4 * Support Blackfin CRC HW acceleration.
5 *
6 * Copyright 2012 Analog Devices Inc.
7 *
8 * Licensed under the GPL-2.
9 */
10
11#include <linux/err.h>
12#include <linux/device.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/errno.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/irq.h>
19#include <linux/io.h>
20#include <linux/platform_device.h>
21#include <linux/scatterlist.h>
22#include <linux/dma-mapping.h>
23#include <linux/delay.h>
24#include <linux/crypto.h>
25#include <linux/cryptohash.h>
26#include <crypto/scatterwalk.h>
27#include <crypto/algapi.h>
28#include <crypto/hash.h>
29#include <crypto/internal/hash.h>
30#include <asm/unaligned.h>
31
32#include <asm/dma.h>
33#include <asm/portmux.h>
34#include <asm/io.h>
35
36#include "bfin_crc.h"
37
38#define CRC_CCRYPTO_QUEUE_LENGTH	5
39
40#define DRIVER_NAME "bfin-hmac-crc"
41#define CHKSUM_DIGEST_SIZE      4
42#define CHKSUM_BLOCK_SIZE       1
43
44#define CRC_MAX_DMA_DESC	100
45
46#define CRC_CRYPTO_STATE_UPDATE		1
47#define CRC_CRYPTO_STATE_FINALUPDATE	2
48#define CRC_CRYPTO_STATE_FINISH		3
49
50struct bfin_crypto_crc {
51	struct list_head	list;
52	struct device		*dev;
53	spinlock_t		lock;
54
55	int			irq;
56	int			dma_ch;
57	u32			poly;
58	struct crc_register	*regs;
59
60	struct ahash_request	*req; /* current request in operation */
61	struct dma_desc_array	*sg_cpu; /* virt addr of sg dma descriptors */
62	dma_addr_t		sg_dma; /* phy addr of sg dma descriptors */
63	u8			*sg_mid_buf;
64	dma_addr_t		sg_mid_dma; /* phy addr of sg mid buffer */
65
66	struct tasklet_struct	done_task;
67	struct crypto_queue	queue; /* waiting requests */
68
69	u8			busy:1; /* crc device in operation flag */
70};
71
72static struct bfin_crypto_crc_list {
73	struct list_head	dev_list;
74	spinlock_t		lock;
75} crc_list;
76
77struct bfin_crypto_crc_reqctx {
78	struct bfin_crypto_crc	*crc;
79
80	unsigned int		total;	/* total request bytes */
81	size_t			sg_buflen; /* bytes for this update */
82	unsigned int		sg_nents;
83	struct scatterlist	*sg; /* sg list head for this update*/
84	struct scatterlist	bufsl[2]; /* chained sg list */
85
86	size_t			bufnext_len;
87	size_t			buflast_len;
88	u8			bufnext[CHKSUM_DIGEST_SIZE]; /* extra bytes for next udpate */
89	u8			buflast[CHKSUM_DIGEST_SIZE]; /* extra bytes from last udpate */
90
91	u8			flag;
92};
93
94struct bfin_crypto_crc_ctx {
95	struct bfin_crypto_crc	*crc;
96	u32			key;
97};
98
99
100/*
101 * derive number of elements in scatterlist
102 */
103static int sg_count(struct scatterlist *sg_list)
104{
105	struct scatterlist *sg = sg_list;
106	int sg_nents = 1;
107
108	if (sg_list == NULL)
109		return 0;
110
111	while (!sg_is_last(sg)) {
112		sg_nents++;
113		sg = sg_next(sg);
114	}
115
116	return sg_nents;
117}
118
119/*
120 * get element in scatter list by given index
121 */
122static struct scatterlist *sg_get(struct scatterlist *sg_list, unsigned int nents,
123				unsigned int index)
124{
125	struct scatterlist *sg = NULL;
126	int i;
127
128	for_each_sg(sg_list, sg, nents, i)
129		if (i == index)
130			break;
131
132	return sg;
133}
134
135static int bfin_crypto_crc_init_hw(struct bfin_crypto_crc *crc, u32 key)
136{
137	writel(0, &crc->regs->datacntrld);
138	writel(MODE_CALC_CRC << OPMODE_OFFSET, &crc->regs->control);
139	writel(key, &crc->regs->curresult);
140
141	/* setup CRC interrupts */
142	writel(CMPERRI | DCNTEXPI, &crc->regs->status);
143	writel(CMPERRI | DCNTEXPI, &crc->regs->intrenset);
144
145	return 0;
146}
147
148static int bfin_crypto_crc_init(struct ahash_request *req)
149{
150	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
151	struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
152	struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
153	struct bfin_crypto_crc *crc;
154
155	dev_dbg(ctx->crc->dev, "crc_init\n");
156	spin_lock_bh(&crc_list.lock);
157	list_for_each_entry(crc, &crc_list.dev_list, list) {
158		crc_ctx->crc = crc;
159		break;
160	}
161	spin_unlock_bh(&crc_list.lock);
162
163	if (sg_count(req->src) > CRC_MAX_DMA_DESC) {
164		dev_dbg(ctx->crc->dev, "init: requested sg list is too big > %d\n",
165			CRC_MAX_DMA_DESC);
166		return -EINVAL;
167	}
168
169	ctx->crc = crc;
170	ctx->bufnext_len = 0;
171	ctx->buflast_len = 0;
172	ctx->sg_buflen = 0;
173	ctx->total = 0;
174	ctx->flag = 0;
175
176	/* init crc results */
177	put_unaligned_le32(crc_ctx->key, req->result);
178
179	dev_dbg(ctx->crc->dev, "init: digest size: %d\n",
180		crypto_ahash_digestsize(tfm));
181
182	return bfin_crypto_crc_init_hw(crc, crc_ctx->key);
183}
184
185static void bfin_crypto_crc_config_dma(struct bfin_crypto_crc *crc)
186{
187	struct scatterlist *sg;
188	struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(crc->req);
189	int i = 0, j = 0;
190	unsigned long dma_config;
191	unsigned int dma_count;
192	unsigned int dma_addr;
193	unsigned int mid_dma_count = 0;
194	int dma_mod;
195
196	dma_map_sg(crc->dev, ctx->sg, ctx->sg_nents, DMA_TO_DEVICE);
197
198	for_each_sg(ctx->sg, sg, ctx->sg_nents, j) {
199		dma_addr = sg_dma_address(sg);
200		/* deduce extra bytes in last sg */
201		if (sg_is_last(sg))
202			dma_count = sg_dma_len(sg) - ctx->bufnext_len;
203		else
204			dma_count = sg_dma_len(sg);
205
206		if (mid_dma_count) {
207			/* Append last middle dma buffer to 4 bytes with first
208			   bytes in current sg buffer. Move addr of current
209			   sg and deduce the length of current sg.
210			 */
211			memcpy(crc->sg_mid_buf +(i << 2) + mid_dma_count,
212				sg_virt(sg),
213				CHKSUM_DIGEST_SIZE - mid_dma_count);
214			dma_addr += CHKSUM_DIGEST_SIZE - mid_dma_count;
215			dma_count -= CHKSUM_DIGEST_SIZE - mid_dma_count;
216
217			dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 |
218				DMAEN | PSIZE_32 | WDSIZE_32;
219
220			/* setup new dma descriptor for next middle dma */
221			crc->sg_cpu[i].start_addr = crc->sg_mid_dma + (i << 2);
222			crc->sg_cpu[i].cfg = dma_config;
223			crc->sg_cpu[i].x_count = 1;
224			crc->sg_cpu[i].x_modify = CHKSUM_DIGEST_SIZE;
225			dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
226				"cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
227				i, crc->sg_cpu[i].start_addr,
228				crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
229				crc->sg_cpu[i].x_modify);
230			i++;
231		}
232
233		dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 | DMAEN | PSIZE_32;
234		/* chop current sg dma len to multiple of 32 bits */
235		mid_dma_count = dma_count % 4;
236		dma_count &= ~0x3;
237
238		if (dma_addr % 4 == 0) {
239			dma_config |= WDSIZE_32;
240			dma_count >>= 2;
241			dma_mod = 4;
242		} else if (dma_addr % 2 == 0) {
243			dma_config |= WDSIZE_16;
244			dma_count >>= 1;
245			dma_mod = 2;
246		} else {
247			dma_config |= WDSIZE_8;
248			dma_mod = 1;
249		}
250
251		crc->sg_cpu[i].start_addr = dma_addr;
252		crc->sg_cpu[i].cfg = dma_config;
253		crc->sg_cpu[i].x_count = dma_count;
254		crc->sg_cpu[i].x_modify = dma_mod;
255		dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
256			"cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
257			i, crc->sg_cpu[i].start_addr,
258			crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
259			crc->sg_cpu[i].x_modify);
260		i++;
261
262		if (mid_dma_count) {
263			/* copy extra bytes to next middle dma buffer */
264			memcpy(crc->sg_mid_buf + (i << 2),
265				(u8*)sg_virt(sg) + (dma_count << 2),
266				mid_dma_count);
267		}
268	}
269
270	dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 | DMAEN | PSIZE_32 | WDSIZE_32;
271	/* For final update req, append the buffer for next update as well*/
272	if (ctx->bufnext_len && (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE ||
273		ctx->flag == CRC_CRYPTO_STATE_FINISH)) {
274		crc->sg_cpu[i].start_addr = dma_map_single(crc->dev, ctx->bufnext,
275						CHKSUM_DIGEST_SIZE, DMA_TO_DEVICE);
276		crc->sg_cpu[i].cfg = dma_config;
277		crc->sg_cpu[i].x_count = 1;
278		crc->sg_cpu[i].x_modify = CHKSUM_DIGEST_SIZE;
279		dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
280			"cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
281			i, crc->sg_cpu[i].start_addr,
282			crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
283			crc->sg_cpu[i].x_modify);
284		i++;
285	}
286
287	if (i == 0)
288		return;
289
290	/* Set the last descriptor to stop mode */
291	crc->sg_cpu[i - 1].cfg &= ~(DMAFLOW | NDSIZE);
292	crc->sg_cpu[i - 1].cfg |= DI_EN;
293	set_dma_curr_desc_addr(crc->dma_ch, (unsigned long *)crc->sg_dma);
294	set_dma_x_count(crc->dma_ch, 0);
295	set_dma_x_modify(crc->dma_ch, 0);
296	set_dma_config(crc->dma_ch, dma_config);
297}
298
299static int bfin_crypto_crc_handle_queue(struct bfin_crypto_crc *crc,
300				  struct ahash_request *req)
301{
302	struct crypto_async_request *async_req, *backlog;
303	struct bfin_crypto_crc_reqctx *ctx;
304	struct scatterlist *sg;
305	int ret = 0;
306	int nsg, i, j;
307	unsigned int nextlen;
308	unsigned long flags;
309	u32 reg;
310
311	spin_lock_irqsave(&crc->lock, flags);
312	if (req)
313		ret = ahash_enqueue_request(&crc->queue, req);
314	if (crc->busy) {
315		spin_unlock_irqrestore(&crc->lock, flags);
316		return ret;
317	}
318	backlog = crypto_get_backlog(&crc->queue);
319	async_req = crypto_dequeue_request(&crc->queue);
320	if (async_req)
321		crc->busy = 1;
322	spin_unlock_irqrestore(&crc->lock, flags);
323
324	if (!async_req)
325		return ret;
326
327	if (backlog)
328		backlog->complete(backlog, -EINPROGRESS);
329
330	req = ahash_request_cast(async_req);
331	crc->req = req;
332	ctx = ahash_request_ctx(req);
333	ctx->sg = NULL;
334	ctx->sg_buflen = 0;
335	ctx->sg_nents = 0;
336
337	dev_dbg(crc->dev, "handling new req, flag=%u, nbytes: %d\n",
338						ctx->flag, req->nbytes);
339
340	if (ctx->flag == CRC_CRYPTO_STATE_FINISH) {
341		if (ctx->bufnext_len == 0) {
342			crc->busy = 0;
343			return 0;
344		}
345
346		/* Pack last crc update buffer to 32bit */
347		memset(ctx->bufnext + ctx->bufnext_len, 0,
348				CHKSUM_DIGEST_SIZE - ctx->bufnext_len);
349	} else {
350		/* Pack small data which is less than 32bit to buffer for next update. */
351		if (ctx->bufnext_len + req->nbytes < CHKSUM_DIGEST_SIZE) {
352			memcpy(ctx->bufnext + ctx->bufnext_len,
353				sg_virt(req->src), req->nbytes);
354			ctx->bufnext_len += req->nbytes;
355			if (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE &&
356				ctx->bufnext_len) {
357				goto finish_update;
358			} else {
359				crc->busy = 0;
360				return 0;
361			}
362		}
363
364		if (ctx->bufnext_len) {
365			/* Chain in extra bytes of last update */
366			ctx->buflast_len = ctx->bufnext_len;
367			memcpy(ctx->buflast, ctx->bufnext, ctx->buflast_len);
368
369			nsg = ctx->sg_buflen ? 2 : 1;
370			sg_init_table(ctx->bufsl, nsg);
371			sg_set_buf(ctx->bufsl, ctx->buflast, ctx->buflast_len);
372			if (nsg > 1)
373				scatterwalk_sg_chain(ctx->bufsl, nsg,
374						req->src);
375			ctx->sg = ctx->bufsl;
376		} else
377			ctx->sg = req->src;
378
379		/* Chop crc buffer size to multiple of 32 bit */
380		nsg = ctx->sg_nents = sg_count(ctx->sg);
381		ctx->sg_buflen = ctx->buflast_len + req->nbytes;
382		ctx->bufnext_len = ctx->sg_buflen % 4;
383		ctx->sg_buflen &= ~0x3;
384
385		if (ctx->bufnext_len) {
386			/* copy extra bytes to buffer for next update */
387			memset(ctx->bufnext, 0, CHKSUM_DIGEST_SIZE);
388			nextlen = ctx->bufnext_len;
389			for (i = nsg - 1; i >= 0; i--) {
390				sg = sg_get(ctx->sg, nsg, i);
391				j = min(nextlen, sg_dma_len(sg));
392				memcpy(ctx->bufnext + nextlen - j,
393					sg_virt(sg) + sg_dma_len(sg) - j, j);
394				if (j == sg_dma_len(sg))
395					ctx->sg_nents--;
396				nextlen -= j;
397				if (nextlen == 0)
398					break;
399			}
400		}
401	}
402
403finish_update:
404	if (ctx->bufnext_len && (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE ||
405		ctx->flag == CRC_CRYPTO_STATE_FINISH))
406		ctx->sg_buflen += CHKSUM_DIGEST_SIZE;
407
408	/* set CRC data count before start DMA */
409	writel(ctx->sg_buflen >> 2, &crc->regs->datacnt);
410
411	/* setup and enable CRC DMA */
412	bfin_crypto_crc_config_dma(crc);
413
414	/* finally kick off CRC operation */
415	reg = readl(&crc->regs->control);
416	writel(reg | BLKEN, &crc->regs->control);
417
418	return -EINPROGRESS;
419}
420
421static int bfin_crypto_crc_update(struct ahash_request *req)
422{
423	struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
424
425	if (!req->nbytes)
426		return 0;
427
428	dev_dbg(ctx->crc->dev, "crc_update\n");
429	ctx->total += req->nbytes;
430	ctx->flag = CRC_CRYPTO_STATE_UPDATE;
431
432	return bfin_crypto_crc_handle_queue(ctx->crc, req);
433}
434
435static int bfin_crypto_crc_final(struct ahash_request *req)
436{
437	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
438	struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
439	struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
440
441	dev_dbg(ctx->crc->dev, "crc_final\n");
442	ctx->flag = CRC_CRYPTO_STATE_FINISH;
443	crc_ctx->key = 0;
444
445	return bfin_crypto_crc_handle_queue(ctx->crc, req);
446}
447
448static int bfin_crypto_crc_finup(struct ahash_request *req)
449{
450	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
451	struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
452	struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
453
454	dev_dbg(ctx->crc->dev, "crc_finishupdate\n");
455	ctx->total += req->nbytes;
456	ctx->flag = CRC_CRYPTO_STATE_FINALUPDATE;
457	crc_ctx->key = 0;
458
459	return bfin_crypto_crc_handle_queue(ctx->crc, req);
460}
461
462static int bfin_crypto_crc_digest(struct ahash_request *req)
463{
464	int ret;
465
466	ret = bfin_crypto_crc_init(req);
467	if (ret)
468		return ret;
469
470	return bfin_crypto_crc_finup(req);
471}
472
473static int bfin_crypto_crc_setkey(struct crypto_ahash *tfm, const u8 *key,
474			unsigned int keylen)
475{
476	struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
477
478	dev_dbg(crc_ctx->crc->dev, "crc_setkey\n");
479	if (keylen != CHKSUM_DIGEST_SIZE) {
480		crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
481		return -EINVAL;
482	}
483
484	crc_ctx->key = get_unaligned_le32(key);
485
486	return 0;
487}
488
489static int bfin_crypto_crc_cra_init(struct crypto_tfm *tfm)
490{
491	struct bfin_crypto_crc_ctx *crc_ctx = crypto_tfm_ctx(tfm);
492
493	crc_ctx->key = 0;
494	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
495				 sizeof(struct bfin_crypto_crc_reqctx));
496
497	return 0;
498}
499
500static void bfin_crypto_crc_cra_exit(struct crypto_tfm *tfm)
501{
502}
503
504static struct ahash_alg algs = {
505	.init		= bfin_crypto_crc_init,
506	.update		= bfin_crypto_crc_update,
507	.final		= bfin_crypto_crc_final,
508	.finup		= bfin_crypto_crc_finup,
509	.digest		= bfin_crypto_crc_digest,
510	.setkey		= bfin_crypto_crc_setkey,
511	.halg.digestsize	= CHKSUM_DIGEST_SIZE,
512	.halg.base	= {
513		.cra_name		= "hmac(crc32)",
514		.cra_driver_name	= DRIVER_NAME,
515		.cra_priority		= 100,
516		.cra_flags		= CRYPTO_ALG_TYPE_AHASH |
517						CRYPTO_ALG_ASYNC,
518		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
519		.cra_ctxsize		= sizeof(struct bfin_crypto_crc_ctx),
520		.cra_alignmask		= 3,
521		.cra_module		= THIS_MODULE,
522		.cra_init		= bfin_crypto_crc_cra_init,
523		.cra_exit		= bfin_crypto_crc_cra_exit,
524	}
525};
526
527static void bfin_crypto_crc_done_task(unsigned long data)
528{
529	struct bfin_crypto_crc *crc = (struct bfin_crypto_crc *)data;
530
531	bfin_crypto_crc_handle_queue(crc, NULL);
532}
533
534static irqreturn_t bfin_crypto_crc_handler(int irq, void *dev_id)
535{
536	struct bfin_crypto_crc *crc = dev_id;
537	u32 reg;
538
539	if (readl(&crc->regs->status) & DCNTEXP) {
540		writel(DCNTEXP, &crc->regs->status);
541
542		/* prepare results */
543		put_unaligned_le32(readl(&crc->regs->result),
544			crc->req->result);
545
546		reg = readl(&crc->regs->control);
547		writel(reg & ~BLKEN, &crc->regs->control);
548		crc->busy = 0;
549
550		if (crc->req->base.complete)
551			crc->req->base.complete(&crc->req->base, 0);
552
553		tasklet_schedule(&crc->done_task);
554
555		return IRQ_HANDLED;
556	} else
557		return IRQ_NONE;
558}
559
560#ifdef CONFIG_PM
561/**
562 *	bfin_crypto_crc_suspend - suspend crc device
563 *	@pdev: device being suspended
564 *	@state: requested suspend state
565 */
566static int bfin_crypto_crc_suspend(struct platform_device *pdev, pm_message_t state)
567{
568	struct bfin_crypto_crc *crc = platform_get_drvdata(pdev);
569	int i = 100000;
570
571	while ((readl(&crc->regs->control) & BLKEN) && --i)
572		cpu_relax();
573
574	if (i == 0)
575		return -EBUSY;
576
577	return 0;
578}
579#else
580# define bfin_crypto_crc_suspend NULL
581#endif
582
583#define bfin_crypto_crc_resume NULL
584
585/**
586 *	bfin_crypto_crc_probe - Initialize module
587 *
588 */
589static int bfin_crypto_crc_probe(struct platform_device *pdev)
590{
591	struct device *dev = &pdev->dev;
592	struct resource *res;
593	struct bfin_crypto_crc *crc;
594	unsigned int timeout = 100000;
595	int ret;
596
597	crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL);
598	if (!crc) {
599		dev_err(&pdev->dev, "fail to malloc bfin_crypto_crc\n");
600		return -ENOMEM;
601	}
602
603	crc->dev = dev;
604
605	INIT_LIST_HEAD(&crc->list);
606	spin_lock_init(&crc->lock);
607	tasklet_init(&crc->done_task, bfin_crypto_crc_done_task, (unsigned long)crc);
608	crypto_init_queue(&crc->queue, CRC_CCRYPTO_QUEUE_LENGTH);
609
610	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
611	if (res == NULL) {
612		dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
613		return -ENOENT;
614	}
615
616	crc->regs = devm_ioremap_resource(dev, res);
617	if (IS_ERR((void *)crc->regs)) {
618		dev_err(&pdev->dev, "Cannot map CRC IO\n");
619		return PTR_ERR((void *)crc->regs);
620	}
621
622	crc->irq = platform_get_irq(pdev, 0);
623	if (crc->irq < 0) {
624		dev_err(&pdev->dev, "No CRC DCNTEXP IRQ specified\n");
625		return -ENOENT;
626	}
627
628	ret = devm_request_irq(dev, crc->irq, bfin_crypto_crc_handler,
629			IRQF_SHARED, dev_name(dev), crc);
630	if (ret) {
631		dev_err(&pdev->dev, "Unable to request blackfin crc irq\n");
632		return ret;
633	}
634
635	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
636	if (res == NULL) {
637		dev_err(&pdev->dev, "No CRC DMA channel specified\n");
638		return -ENOENT;
639	}
640	crc->dma_ch = res->start;
641
642	ret = request_dma(crc->dma_ch, dev_name(dev));
643	if (ret) {
644		dev_err(&pdev->dev, "Unable to attach Blackfin CRC DMA channel\n");
645		return ret;
646	}
647
648	crc->sg_cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE, &crc->sg_dma, GFP_KERNEL);
649	if (crc->sg_cpu == NULL) {
650		ret = -ENOMEM;
651		goto out_error_dma;
652	}
653	/*
654	 * need at most CRC_MAX_DMA_DESC sg + CRC_MAX_DMA_DESC middle  +
655	 * 1 last + 1 next dma descriptors
656	 */
657	crc->sg_mid_buf = (u8 *)(crc->sg_cpu + ((CRC_MAX_DMA_DESC + 1) << 1));
658	crc->sg_mid_dma = crc->sg_dma + sizeof(struct dma_desc_array)
659			* ((CRC_MAX_DMA_DESC + 1) << 1);
660
661	writel(0, &crc->regs->control);
662	crc->poly = (u32)pdev->dev.platform_data;
663	writel(crc->poly, &crc->regs->poly);
664
665	while (!(readl(&crc->regs->status) & LUTDONE) && (--timeout) > 0)
666		cpu_relax();
667
668	if (timeout == 0)
669		dev_info(&pdev->dev, "init crc poly timeout\n");
670
671	platform_set_drvdata(pdev, crc);
672
673	spin_lock(&crc_list.lock);
674	list_add(&crc->list, &crc_list.dev_list);
675	spin_unlock(&crc_list.lock);
676
677	if (list_is_singular(&crc_list.dev_list)) {
678		ret = crypto_register_ahash(&algs);
679		if (ret) {
680			dev_err(&pdev->dev,
681				"Can't register crypto ahash device\n");
682			goto out_error_dma;
683		}
684	}
685
686	dev_info(&pdev->dev, "initialized\n");
687
688	return 0;
689
690out_error_dma:
691	if (crc->sg_cpu)
692		dma_free_coherent(&pdev->dev, PAGE_SIZE, crc->sg_cpu, crc->sg_dma);
693	free_dma(crc->dma_ch);
694
695	return ret;
696}
697
698/**
699 *	bfin_crypto_crc_remove - Initialize module
700 *
701 */
702static int bfin_crypto_crc_remove(struct platform_device *pdev)
703{
704	struct bfin_crypto_crc *crc = platform_get_drvdata(pdev);
705
706	if (!crc)
707		return -ENODEV;
708
709	spin_lock(&crc_list.lock);
710	list_del(&crc->list);
711	spin_unlock(&crc_list.lock);
712
713	crypto_unregister_ahash(&algs);
714	tasklet_kill(&crc->done_task);
715	free_dma(crc->dma_ch);
716
717	return 0;
718}
719
720static struct platform_driver bfin_crypto_crc_driver = {
721	.probe     = bfin_crypto_crc_probe,
722	.remove    = bfin_crypto_crc_remove,
723	.suspend   = bfin_crypto_crc_suspend,
724	.resume    = bfin_crypto_crc_resume,
725	.driver    = {
726		.name  = DRIVER_NAME,
727	},
728};
729
730/**
731 *	bfin_crypto_crc_mod_init - Initialize module
732 *
733 *	Checks the module params and registers the platform driver.
734 *	Real work is in the platform probe function.
735 */
736static int __init bfin_crypto_crc_mod_init(void)
737{
738	int ret;
739
740	pr_info("Blackfin hardware CRC crypto driver\n");
741
742	INIT_LIST_HEAD(&crc_list.dev_list);
743	spin_lock_init(&crc_list.lock);
744
745	ret = platform_driver_register(&bfin_crypto_crc_driver);
746	if (ret) {
747		pr_err("unable to register driver\n");
748		return ret;
749	}
750
751	return 0;
752}
753
754/**
755 *	bfin_crypto_crc_mod_exit - Deinitialize module
756 */
757static void __exit bfin_crypto_crc_mod_exit(void)
758{
759	platform_driver_unregister(&bfin_crypto_crc_driver);
760}
761
762module_init(bfin_crypto_crc_mod_init);
763module_exit(bfin_crypto_crc_mod_exit);
764
765MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
766MODULE_DESCRIPTION("Blackfin CRC hardware crypto driver");
767MODULE_LICENSE("GPL");
768