crypto: atmel - add Atmel SHA1/SHA256 driver

Signed-off-by: Nicolas Royer <nicolas@eukrea.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Eric Bénard <eric@eukrea.com>
Tested-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 1112 insertions, 0 deletions

diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
new file mode 100644
index 000000000000..f938b9d79b66
--- /dev/null
+++ b/drivers/crypto/atmel-sha.c
@@ -0,0 +1,1112 @@
+/*
+ * Cryptographic API.
+ *
+ * Support for ATMEL SHA1/SHA256 HW acceleration.
+ *
+ * Copyright (c) 2012 Eukréa Electromatique - ATMEL
+ * Author: Nicolas Royer <nicolas@eukrea.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Some ideas are from omap-sham.c drivers.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/hw_random.h>
+#include <linux/platform_device.h>
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/crypto.h>
+#include <linux/cryptohash.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/algapi.h>
+#include <crypto/sha.h>
+#include <crypto/hash.h>
+#include <crypto/internal/hash.h>
+#include "atmel-sha-regs.h"
+
+/* SHA flags */
+#define SHA_FLAGS_BUSY			BIT(0)
+#define	SHA_FLAGS_FINAL			BIT(1)
+#define SHA_FLAGS_DMA_ACTIVE	BIT(2)
+#define SHA_FLAGS_OUTPUT_READY	BIT(3)
+#define SHA_FLAGS_INIT			BIT(4)
+#define SHA_FLAGS_CPU			BIT(5)
+#define SHA_FLAGS_DMA_READY		BIT(6)
+
+#define SHA_FLAGS_FINUP		BIT(16)
+#define SHA_FLAGS_SG		BIT(17)
+#define SHA_FLAGS_SHA1		BIT(18)
+#define SHA_FLAGS_SHA256	BIT(19)
+#define SHA_FLAGS_ERROR		BIT(20)
+#define SHA_FLAGS_PAD		BIT(21)
+
+#define SHA_FLAGS_DUALBUFF	BIT(24)
+
+#define SHA_OP_UPDATE	1
+#define SHA_OP_FINAL	2
+
+#define SHA_BUFFER_LEN		PAGE_SIZE
+
+#define ATMEL_SHA_DMA_THRESHOLD		56
+
+
+struct atmel_sha_dev;
+
+struct atmel_sha_reqctx {
+	struct atmel_sha_dev	*dd;
+	unsigned long	flags;
+	unsigned long	op;
+
+	u8	digest[SHA256_DIGEST_SIZE] __aligned(sizeof(u32));
+	size_t	digcnt;
+	size_t	bufcnt;
+	size_t	buflen;
+	dma_addr_t	dma_addr;
+
+	/* walk state */
+	struct scatterlist	*sg;
+	unsigned int	offset;	/* offset in current sg */
+	unsigned int	total;	/* total request */
+
+	u8	buffer[0] __aligned(sizeof(u32));
+};
+
+struct atmel_sha_ctx {
+	struct atmel_sha_dev	*dd;
+
+	unsigned long		flags;
+
+	/* fallback stuff */
+	struct crypto_shash	*fallback;
+
+};
+
+#define ATMEL_SHA_QUEUE_LENGTH	1
+
+struct atmel_sha_dev {
+	struct list_head	list;
+	unsigned long		phys_base;
+	struct device		*dev;
+	struct clk			*iclk;
+	int					irq;
+	void __iomem		*io_base;
+
+	spinlock_t		lock;
+	int			err;
+	struct tasklet_struct	done_task;
+
+	unsigned long		flags;
+	struct crypto_queue	queue;
+	struct ahash_request	*req;
+};
+
+struct atmel_sha_drv {
+	struct list_head	dev_list;
+	spinlock_t		lock;
+};
+
+static struct atmel_sha_drv atmel_sha = {
+	.dev_list = LIST_HEAD_INIT(atmel_sha.dev_list),
+	.lock = __SPIN_LOCK_UNLOCKED(atmel_sha.lock),
+};
+
+static inline u32 atmel_sha_read(struct atmel_sha_dev *dd, u32 offset)
+{
+	return readl_relaxed(dd->io_base + offset);
+}
+
+static inline void atmel_sha_write(struct atmel_sha_dev *dd,
+					u32 offset, u32 value)
+{
+	writel_relaxed(value, dd->io_base + offset);
+}
+
+static void atmel_sha_dualbuff_test(struct atmel_sha_dev *dd)
+{
+	atmel_sha_write(dd, SHA_MR, SHA_MR_DUALBUFF);
+
+	if (atmel_sha_read(dd, SHA_MR) & SHA_MR_DUALBUFF)
+		dd->flags |= SHA_FLAGS_DUALBUFF;
+}
+
+static size_t atmel_sha_append_sg(struct atmel_sha_reqctx *ctx)
+{
+	size_t count;
+
+	while ((ctx->bufcnt < ctx->buflen) && ctx->total) {
+		count = min(ctx->sg->length - ctx->offset, ctx->total);
+		count = min(count, ctx->buflen - ctx->bufcnt);
+
+		if (count <= 0)
+			break;
+
+		scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, ctx->sg,
+			ctx->offset, count, 0);
+
+		ctx->bufcnt += count;
+		ctx->offset += count;
+		ctx->total -= count;
+
+		if (ctx->offset == ctx->sg->length) {
+			ctx->sg = sg_next(ctx->sg);
+			if (ctx->sg)
+				ctx->offset = 0;
+			else
+				ctx->total = 0;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * The purpose of this padding is to ensure that the padded message
+ * is a multiple of 512 bits. The bit "1" is appended at the end of
+ * the message followed by "padlen-1" zero bits. Then a 64 bits block
+ * equals to the message length in bits is appended.
+ *
+ * padlen is calculated as followed:
+ *  - if message length < 56 bytes then padlen = 56 - message length
+ *  - else padlen = 64 + 56 - message length
+ */
+static void atmel_sha_fill_padding(struct atmel_sha_reqctx *ctx, int length)
+{
+	unsigned int index, padlen;
+	u64 bits;
+	u64 size;
+
+	bits = (ctx->bufcnt + ctx->digcnt + length) << 3;
+	size = cpu_to_be64(bits);
+
+	index = ctx->bufcnt & 0x3f;
+	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
+	*(ctx->buffer + ctx->bufcnt) = 0x80;
+	memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
+	memcpy(ctx->buffer + ctx->bufcnt + padlen, &size, 8);
+	ctx->bufcnt += padlen + 8;
+	ctx->flags |= SHA_FLAGS_PAD;
+}
+
+static int atmel_sha_init(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct atmel_sha_ctx *tctx = crypto_ahash_ctx(tfm);
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	struct atmel_sha_dev *dd = NULL;
+	struct atmel_sha_dev *tmp;
+
+	spin_lock_bh(&atmel_sha.lock);
+	if (!tctx->dd) {
+		list_for_each_entry(tmp, &atmel_sha.dev_list, list) {
+			dd = tmp;
+			break;
+		}
+		tctx->dd = dd;
+	} else {
+		dd = tctx->dd;
+	}
+
+	spin_unlock_bh(&atmel_sha.lock);
+
+	ctx->dd = dd;
+
+	ctx->flags = 0;
+
+	dev_dbg(dd->dev, "init: digest size: %d\n",
+		crypto_ahash_digestsize(tfm));
+
+	if (crypto_ahash_digestsize(tfm) == SHA1_DIGEST_SIZE)
+		ctx->flags |= SHA_FLAGS_SHA1;
+	else if (crypto_ahash_digestsize(tfm) == SHA256_DIGEST_SIZE)
+		ctx->flags |= SHA_FLAGS_SHA256;
+
+	ctx->bufcnt = 0;
+	ctx->digcnt = 0;
+	ctx->buflen = SHA_BUFFER_LEN;
+
+	return 0;
+}
+
+static void atmel_sha_write_ctrl(struct atmel_sha_dev *dd, int dma)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	u32 valcr = 0, valmr = SHA_MR_MODE_AUTO;
+
+	if (likely(dma)) {
+		atmel_sha_write(dd, SHA_IER, SHA_INT_TXBUFE);
+		valmr = SHA_MR_MODE_PDC;
+		if (dd->flags & SHA_FLAGS_DUALBUFF)
+			valmr = SHA_MR_DUALBUFF;
+	} else {
+		atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
+	}
+
+	if (ctx->flags & SHA_FLAGS_SHA256)
+		valmr |= SHA_MR_ALGO_SHA256;
+
+	/* Setting CR_FIRST only for the first iteration */
+	if (!ctx->digcnt)
+		valcr = SHA_CR_FIRST;
+
+	atmel_sha_write(dd, SHA_CR, valcr);
+	atmel_sha_write(dd, SHA_MR, valmr);
+}
+
+static int atmel_sha_xmit_cpu(struct atmel_sha_dev *dd, const u8 *buf,
+			      size_t length, int final)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	int count, len32;
+	const u32 *buffer = (const u32 *)buf;
+
+	dev_dbg(dd->dev, "xmit_cpu: digcnt: %d, length: %d, final: %d\n",
+						ctx->digcnt, length, final);
+
+	atmel_sha_write_ctrl(dd, 0);
+
+	/* should be non-zero before next lines to disable clocks later */
+	ctx->digcnt += length;
+
+	if (final)
+		dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */
+
+	len32 = DIV_ROUND_UP(length, sizeof(u32));
+
+	dd->flags |= SHA_FLAGS_CPU;
+
+	for (count = 0; count < len32; count++)
+		atmel_sha_write(dd, SHA_REG_DIN(count), buffer[count]);
+
+	return -EINPROGRESS;
+}
+
+static int atmel_sha_xmit_pdc(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
+		size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	int len32;
+
+	dev_dbg(dd->dev, "xmit_pdc: digcnt: %d, length: %d, final: %d\n",
+						ctx->digcnt, length1, final);
+
+	len32 = DIV_ROUND_UP(length1, sizeof(u32));
+	atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTDIS);
+	atmel_sha_write(dd, SHA_TPR, dma_addr1);
+	atmel_sha_write(dd, SHA_TCR, len32);
+
+	len32 = DIV_ROUND_UP(length2, sizeof(u32));
+	atmel_sha_write(dd, SHA_TNPR, dma_addr2);
+	atmel_sha_write(dd, SHA_TNCR, len32);
+
+	atmel_sha_write_ctrl(dd, 1);
+
+	/* should be non-zero before next lines to disable clocks later */
+	ctx->digcnt += length1;
+
+	if (final)
+		dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */
+
+	dd->flags |=  SHA_FLAGS_DMA_ACTIVE;
+
+	/* Start DMA transfer */
+	atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTEN);
+
+	return -EINPROGRESS;
+}
+
+static int atmel_sha_update_cpu(struct atmel_sha_dev *dd)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	int bufcnt;
+
+	atmel_sha_append_sg(ctx);
+	atmel_sha_fill_padding(ctx, 0);
+
+	bufcnt = ctx->bufcnt;
+	ctx->bufcnt = 0;
+
+	return atmel_sha_xmit_cpu(dd, ctx->buffer, bufcnt, 1);
+}
+
+static int atmel_sha_xmit_dma_map(struct atmel_sha_dev *dd,
+					struct atmel_sha_reqctx *ctx,
+					size_t length, int final)
+{
+	ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
+				ctx->buflen + SHA1_BLOCK_SIZE, DMA_TO_DEVICE);
+	if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
+		dev_err(dd->dev, "dma %u bytes error\n", ctx->buflen +
+				SHA1_BLOCK_SIZE);
+		return -EINVAL;
+	}
+
+	ctx->flags &= ~SHA_FLAGS_SG;
+
+	/* next call does not fail... so no unmap in the case of error */
+	return atmel_sha_xmit_pdc(dd, ctx->dma_addr, length, 0, 0, final);
+}
+
+static int atmel_sha_update_dma_slow(struct atmel_sha_dev *dd)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	unsigned int final;
+	size_t count;
+
+	atmel_sha_append_sg(ctx);
+
+	final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;
+
+	dev_dbg(dd->dev, "slow: bufcnt: %u, digcnt: %d, final: %d\n",
+					 ctx->bufcnt, ctx->digcnt, final);
+
+	if (final)
+		atmel_sha_fill_padding(ctx, 0);
+
+	if (final || (ctx->bufcnt == ctx->buflen && ctx->total)) {
+		count = ctx->bufcnt;
+		ctx->bufcnt = 0;
+		return atmel_sha_xmit_dma_map(dd, ctx, count, final);
+	}
+
+	return 0;
+}
+
+static int atmel_sha_update_dma_start(struct atmel_sha_dev *dd)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+	unsigned int length, final, tail;
+	struct scatterlist *sg;
+	unsigned int count;
+
+	if (!ctx->total)
+		return 0;
+
+	if (ctx->bufcnt || ctx->offset)
+		return atmel_sha_update_dma_slow(dd);
+
+	dev_dbg(dd->dev, "fast: digcnt: %d, bufcnt: %u, total: %u\n",
+			ctx->digcnt, ctx->bufcnt, ctx->total);
+
+	sg = ctx->sg;
+
+	if (!IS_ALIGNED(sg->offset, sizeof(u32)))
+		return atmel_sha_update_dma_slow(dd);
+
+	if (!sg_is_last(sg) && !IS_ALIGNED(sg->length, SHA1_BLOCK_SIZE))
+		/* size is not SHA1_BLOCK_SIZE aligned */
+		return atmel_sha_update_dma_slow(dd);
+
+	length = min(ctx->total, sg->length);
+
+	if (sg_is_last(sg)) {
+		if (!(ctx->flags & SHA_FLAGS_FINUP)) {
+			/* not last sg must be SHA1_BLOCK_SIZE aligned */
+			tail = length & (SHA1_BLOCK_SIZE - 1);
+			length -= tail;
+			if (length == 0) {
+				/* offset where to start slow */
+				ctx->offset = length;
+				return atmel_sha_update_dma_slow(dd);
+			}
+		}
+	}
+
+	ctx->total -= length;
+	ctx->offset = length; /* offset where to start slow */
+
+	final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;
+
+	/* Add padding */
+	if (final) {
+		tail = length & (SHA1_BLOCK_SIZE - 1);
+		length -= tail;
+		ctx->total += tail;
+		ctx->offset = length; /* offset where to start slow */
+
+		sg = ctx->sg;
+		atmel_sha_append_sg(ctx);
+
+		atmel_sha_fill_padding(ctx, length);
+
+		ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
+			ctx->buflen + SHA1_BLOCK_SIZE, DMA_TO_DEVICE);
+		if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
+			dev_err(dd->dev, "dma %u bytes error\n",
+				ctx->buflen + SHA1_BLOCK_SIZE);
+			return -EINVAL;
+		}
+
+		if (length == 0) {
+			ctx->flags &= ~SHA_FLAGS_SG;
+			count = ctx->bufcnt;
+			ctx->bufcnt = 0;
+			return atmel_sha_xmit_pdc(dd, ctx->dma_addr, count, 0,
+					0, final);
+		} else {
+			ctx->sg = sg;
+			if (!dma_map_sg(dd->dev, ctx->sg, 1,
+				DMA_TO_DEVICE)) {
+					dev_err(dd->dev, "dma_map_sg  error\n");
+					return -EINVAL;
+			}
+
+			ctx->flags |= SHA_FLAGS_SG;
+
+			count = ctx->bufcnt;
+			ctx->bufcnt = 0;
+			return atmel_sha_xmit_pdc(dd, sg_dma_address(ctx->sg),
+					length, ctx->dma_addr, count, final);
+		}
+	}
+
+	if (!dma_map_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE)) {
+		dev_err(dd->dev, "dma_map_sg  error\n");
+		return -EINVAL;
+	}
+
+	ctx->flags |= SHA_FLAGS_SG;
+
+	/* next call does not fail... so no unmap in the case of error */
+	return atmel_sha_xmit_pdc(dd, sg_dma_address(ctx->sg), length, 0,
+								0, final);
+}
+
+static int atmel_sha_update_dma_stop(struct atmel_sha_dev *dd)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
+
+	if (ctx->flags & SHA_FLAGS_SG) {
+		dma_unmap_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE);
+		if (ctx->sg->length == ctx->offset) {
+			ctx->sg = sg_next(ctx->sg);
+			if (ctx->sg)
+				ctx->offset = 0;
+		}
+		if (ctx->flags & SHA_FLAGS_PAD)
+			dma_unmap_single(dd->dev, ctx->dma_addr,
+				ctx->buflen + SHA1_BLOCK_SIZE, DMA_TO_DEVICE);
+	} else {
+		dma_unmap_single(dd->dev, ctx->dma_addr, ctx->buflen +
+						SHA1_BLOCK_SIZE, DMA_TO_DEVICE);
+	}
+
+	return 0;
+}
+
+static int atmel_sha_update_req(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	int err;
+
+	dev_dbg(dd->dev, "update_req: total: %u, digcnt: %d, finup: %d\n",
+		 ctx->total, ctx->digcnt, (ctx->flags & SHA_FLAGS_FINUP) != 0);
+
+	if (ctx->flags & SHA_FLAGS_CPU)
+		err = atmel_sha_update_cpu(dd);
+	else
+		err = atmel_sha_update_dma_start(dd);
+
+	/* wait for dma completion before can take more data */
+	dev_dbg(dd->dev, "update: err: %d, digcnt: %d\n",
+			err, ctx->digcnt);
+
+	return err;
+}
+
+static int atmel_sha_final_req(struct atmel_sha_dev *dd)
+{
+	struct ahash_request *req = dd->req;
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	int err = 0;
+	int count;
+
+	if (ctx->bufcnt >= ATMEL_SHA_DMA_THRESHOLD) {
+		atmel_sha_fill_padding(ctx, 0);
+		count = ctx->bufcnt;
+		ctx->bufcnt = 0;
+		err = atmel_sha_xmit_dma_map(dd, ctx, count, 1);
+	}
+	/* faster to handle last block with cpu */
+	else {
+		atmel_sha_fill_padding(ctx, 0);
+		count = ctx->bufcnt;
+		ctx->bufcnt = 0;
+		err = atmel_sha_xmit_cpu(dd, ctx->buffer, count, 1);
+	}
+
+	dev_dbg(dd->dev, "final_req: err: %d\n", err);
+
+	return err;
+}
+
+static void atmel_sha_copy_hash(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	u32 *hash = (u32 *)ctx->digest;
+	int i;
+
+	if (likely(ctx->flags & SHA_FLAGS_SHA1))
+		for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(u32); i++)
+			hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
+	else
+		for (i = 0; i < SHA256_DIGEST_SIZE / sizeof(u32); i++)
+			hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
+}
+
+static void atmel_sha_copy_ready_hash(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+
+	if (!req->result)
+		return;
+
+	if (likely(ctx->flags & SHA_FLAGS_SHA1))
+		memcpy(req->result, ctx->digest, SHA1_DIGEST_SIZE);
+	else
+		memcpy(req->result, ctx->digest, SHA256_DIGEST_SIZE);
+}
+
+static int atmel_sha_finish(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	struct atmel_sha_dev *dd = ctx->dd;
+	int err = 0;
+
+	if (ctx->digcnt)
+		atmel_sha_copy_ready_hash(req);
+
+	dev_dbg(dd->dev, "digcnt: %d, bufcnt: %d\n", ctx->digcnt,
+		ctx->bufcnt);
+
+	return err;
+}
+
+static void atmel_sha_finish_req(struct ahash_request *req, int err)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	struct atmel_sha_dev *dd = ctx->dd;
+
+	if (!err) {
+		atmel_sha_copy_hash(req);
+		if (SHA_FLAGS_FINAL & dd->flags)
+			err = atmel_sha_finish(req);
+	} else {
+		ctx->flags |= SHA_FLAGS_ERROR;
+	}
+
+	/* atomic operation is not needed here */
+	dd->flags &= ~(SHA_FLAGS_BUSY | SHA_FLAGS_FINAL | SHA_FLAGS_CPU |
+			SHA_FLAGS_DMA_READY | SHA_FLAGS_OUTPUT_READY);
+
+	clk_disable_unprepare(dd->iclk);
+
+	if (req->base.complete)
+		req->base.complete(&req->base, err);
+
+	/* handle new request */
+	tasklet_schedule(&dd->done_task);
+}
+
+static int atmel_sha_hw_init(struct atmel_sha_dev *dd)
+{
+	clk_prepare_enable(dd->iclk);
+
+	if (SHA_FLAGS_INIT & dd->flags) {
+		atmel_sha_write(dd, SHA_CR, SHA_CR_SWRST);
+		atmel_sha_dualbuff_test(dd);
+		dd->flags |= SHA_FLAGS_INIT;
+		dd->err = 0;
+	}
+
+	return 0;
+}
+
+static int atmel_sha_handle_queue(struct atmel_sha_dev *dd,
+				  struct ahash_request *req)
+{
+	struct crypto_async_request *async_req, *backlog;
+	struct atmel_sha_reqctx *ctx;
+	unsigned long flags;
+	int err = 0, ret = 0;
+
+	spin_lock_irqsave(&dd->lock, flags);
+	if (req)
+		ret = ahash_enqueue_request(&dd->queue, req);
+
+	if (SHA_FLAGS_BUSY & dd->flags) {
+		spin_unlock_irqrestore(&dd->lock, flags);
+		return ret;
+	}
+
+	backlog = crypto_get_backlog(&dd->queue);
+	async_req = crypto_dequeue_request(&dd->queue);
+	if (async_req)
+		dd->flags |= SHA_FLAGS_BUSY;
+
+	spin_unlock_irqrestore(&dd->lock, flags);
+
+	if (!async_req)
+		return ret;
+
+	if (backlog)
+		backlog->complete(backlog, -EINPROGRESS);
+
+	req = ahash_request_cast(async_req);
+	dd->req = req;
+	ctx = ahash_request_ctx(req);
+
+	dev_dbg(dd->dev, "handling new req, op: %lu, nbytes: %d\n",
+						ctx->op, req->nbytes);
+
+	err = atmel_sha_hw_init(dd);
+
+	if (err)
+		goto err1;
+
+	if (ctx->op == SHA_OP_UPDATE) {
+		err = atmel_sha_update_req(dd);
+		if (err != -EINPROGRESS && (ctx->flags & SHA_FLAGS_FINUP)) {
+			/* no final() after finup() */
+			err = atmel_sha_final_req(dd);
+		}
+	} else if (ctx->op == SHA_OP_FINAL) {
+		err = atmel_sha_final_req(dd);
+	}
+
+err1:
+	if (err != -EINPROGRESS)
+		/* done_task will not finish it, so do it here */
+		atmel_sha_finish_req(req, err);
+
+	dev_dbg(dd->dev, "exit, err: %d\n", err);
+
+	return ret;
+}
+
+static int atmel_sha_enqueue(struct ahash_request *req, unsigned int op)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
+	struct atmel_sha_dev *dd = tctx->dd;
+
+	ctx->op = op;
+
+	return atmel_sha_handle_queue(dd, req);
+}
+
+static int atmel_sha_update(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+
+	if (!req->nbytes)
+		return 0;
+
+	ctx->total = req->nbytes;
+	ctx->sg = req->src;
+	ctx->offset = 0;
+
+	if (ctx->flags & SHA_FLAGS_FINUP) {
+		if (ctx->bufcnt + ctx->total < ATMEL_SHA_DMA_THRESHOLD)
+			/* faster to use CPU for short transfers */
+			ctx->flags |= SHA_FLAGS_CPU;
+	} else if (ctx->bufcnt + ctx->total < ctx->buflen) {
+		atmel_sha_append_sg(ctx);
+		return 0;
+	}
+	return atmel_sha_enqueue(req, SHA_OP_UPDATE);
+}
+
+static int atmel_sha_final(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
+	struct atmel_sha_dev *dd = tctx->dd;
+
+	int err = 0;
+
+	ctx->flags |= SHA_FLAGS_FINUP;
+
+	if (ctx->flags & SHA_FLAGS_ERROR)
+		return 0; /* uncompleted hash is not needed */
+
+	if (ctx->bufcnt) {
+		return atmel_sha_enqueue(req, SHA_OP_FINAL);
+	} else if (!(ctx->flags & SHA_FLAGS_PAD)) { /* add padding */
+		err = atmel_sha_hw_init(dd);
+		if (err)
+			goto err1;
+
+		dd->flags |= SHA_FLAGS_BUSY;
+		err = atmel_sha_final_req(dd);
+	} else {
+		/* copy ready hash (+ finalize hmac) */
+		return atmel_sha_finish(req);
+	}
+
+err1:
+	if (err != -EINPROGRESS)
+		/* done_task will not finish it, so do it here */
+		atmel_sha_finish_req(req, err);
+
+	return err;
+}
+
+static int atmel_sha_finup(struct ahash_request *req)
+{
+	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
+	int err1, err2;
+
+	ctx->flags |= SHA_FLAGS_FINUP;
+
+	err1 = atmel_sha_update(req);
+	if (err1 == -EINPROGRESS || err1 == -EBUSY)
+		return err1;
+
+	/*
+	 * final() has to be always called to cleanup resources
+	 * even if udpate() failed, except EINPROGRESS
+	 */
+	err2 = atmel_sha_final(req);
+
+	return err1 ?: err2;
+}
+
+static int atmel_sha_digest(struct ahash_request *req)
+{
+	return atmel_sha_init(req) ?: atmel_sha_finup(req);
+}
+
+static int atmel_sha_cra_init_alg(struct crypto_tfm *tfm, const char *alg_base)
+{
+	struct atmel_sha_ctx *tctx = crypto_tfm_ctx(tfm);
+	const char *alg_name = crypto_tfm_alg_name(tfm);
+
+	/* Allocate a fallback and abort if it failed. */
+	tctx->fallback = crypto_alloc_shash(alg_name, 0,
+					    CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(tctx->fallback)) {
+		pr_err("atmel-sha: fallback driver '%s' could not be loaded.\n",
+				alg_name);
+		return PTR_ERR(tctx->fallback);
+	}
+	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+				 sizeof(struct atmel_sha_reqctx) +
+				 SHA_BUFFER_LEN + SHA256_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int atmel_sha_cra_init(struct crypto_tfm *tfm)
+{
+	return atmel_sha_cra_init_alg(tfm, NULL);
+}
+
+static void atmel_sha_cra_exit(struct crypto_tfm *tfm)
+{
+	struct atmel_sha_ctx *tctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_shash(tctx->fallback);
+	tctx->fallback = NULL;
+}
+
+static struct ahash_alg sha_algs[] = {
+{
+	.init		= atmel_sha_init,
+	.update		= atmel_sha_update,
+	.final		= atmel_sha_final,
+	.finup		= atmel_sha_finup,
+	.digest		= atmel_sha_digest,
+	.halg = {
+		.digestsize	= SHA1_DIGEST_SIZE,
+		.base	= {
+			.cra_name		= "sha1",
+			.cra_driver_name	= "atmel-sha1",
+			.cra_priority		= 100,
+			.cra_flags		= CRYPTO_ALG_ASYNC |
+						CRYPTO_ALG_NEED_FALLBACK,
+			.cra_blocksize		= SHA1_BLOCK_SIZE,
+			.cra_ctxsize		= sizeof(struct atmel_sha_ctx),
+			.cra_alignmask		= 0,
+			.cra_module		= THIS_MODULE,
+			.cra_init		= atmel_sha_cra_init,
+			.cra_exit		= atmel_sha_cra_exit,
+		}
+	}
+},
+{
+	.init		= atmel_sha_init,
+	.update		= atmel_sha_update,
+	.final		= atmel_sha_final,
+	.finup		= atmel_sha_finup,
+	.digest		= atmel_sha_digest,
+	.halg = {
+		.digestsize	= SHA256_DIGEST_SIZE,
+		.base	= {
+			.cra_name		= "sha256",
+			.cra_driver_name	= "atmel-sha256",
+			.cra_priority		= 100,
+			.cra_flags		= CRYPTO_ALG_ASYNC |
+						CRYPTO_ALG_NEED_FALLBACK,
+			.cra_blocksize		= SHA256_BLOCK_SIZE,
+			.cra_ctxsize		= sizeof(struct atmel_sha_ctx),
+			.cra_alignmask		= 0,
+			.cra_module		= THIS_MODULE,
+			.cra_init		= atmel_sha_cra_init,
+			.cra_exit		= atmel_sha_cra_exit,
+		}
+	}
+},
+};
+
+static void atmel_sha_done_task(unsigned long data)
+{
+	struct atmel_sha_dev *dd = (struct atmel_sha_dev *)data;
+	int err = 0;
+
+	if (!(SHA_FLAGS_BUSY & dd->flags)) {
+		atmel_sha_handle_queue(dd, NULL);
+		return;
+	}
+
+	if (SHA_FLAGS_CPU & dd->flags) {
+		if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
+			dd->flags &= ~SHA_FLAGS_OUTPUT_READY;
+			goto finish;
+		}
+	} else if (SHA_FLAGS_DMA_READY & dd->flags) {
+		if (SHA_FLAGS_DMA_ACTIVE & dd->flags) {
+			dd->flags &= ~SHA_FLAGS_DMA_ACTIVE;
+			atmel_sha_update_dma_stop(dd);
+			if (dd->err) {
+				err = dd->err;
+				goto finish;
+			}
+		}
+		if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
+			/* hash or semi-hash ready */
+			dd->flags &= ~(SHA_FLAGS_DMA_READY |
+						SHA_FLAGS_OUTPUT_READY);
+			err = atmel_sha_update_dma_start(dd);
+			if (err != -EINPROGRESS)
+				goto finish;
+		}
+	}
+	return;
+
+finish:
+	/* finish curent request */
+	atmel_sha_finish_req(dd->req, err);
+}
+
+static irqreturn_t atmel_sha_irq(int irq, void *dev_id)
+{
+	struct atmel_sha_dev *sha_dd = dev_id;
+	u32 reg;
+
+	reg = atmel_sha_read(sha_dd, SHA_ISR);
+	if (reg & atmel_sha_read(sha_dd, SHA_IMR)) {
+		atmel_sha_write(sha_dd, SHA_IDR, reg);
+		if (SHA_FLAGS_BUSY & sha_dd->flags) {
+			sha_dd->flags |= SHA_FLAGS_OUTPUT_READY;
+			if (!(SHA_FLAGS_CPU & sha_dd->flags))
+				sha_dd->flags |= SHA_FLAGS_DMA_READY;
+			tasklet_schedule(&sha_dd->done_task);
+		} else {
+			dev_warn(sha_dd->dev, "SHA interrupt when no active requests.\n");
+		}
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static void atmel_sha_unregister_algs(struct atmel_sha_dev *dd)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sha_algs); i++)
+		crypto_unregister_ahash(&sha_algs[i]);
+}
+
+static int atmel_sha_register_algs(struct atmel_sha_dev *dd)
+{
+	int err, i, j;
+
+	for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
+		err = crypto_register_ahash(&sha_algs[i]);
+		if (err)
+			goto err_sha_algs;
+	}
+
+	return 0;
+
+err_sha_algs:
+	for (j = 0; j < i; j++)
+		crypto_unregister_ahash(&sha_algs[j]);
+
+	return err;
+}
+
+static int __devinit atmel_sha_probe(struct platform_device *pdev)
+{
+	struct atmel_sha_dev *sha_dd;
+	struct device *dev = &pdev->dev;
+	struct resource *sha_res;
+	unsigned long sha_phys_size;
+	int err;
+
+	sha_dd = kzalloc(sizeof(struct atmel_sha_dev), GFP_KERNEL);
+	if (sha_dd == NULL) {
+		dev_err(dev, "unable to alloc data struct.\n");
+		err = -ENOMEM;
+		goto sha_dd_err;
+	}
+
+	sha_dd->dev = dev;
+
+	platform_set_drvdata(pdev, sha_dd);
+
+	INIT_LIST_HEAD(&sha_dd->list);
+
+	tasklet_init(&sha_dd->done_task, atmel_sha_done_task,
+					(unsigned long)sha_dd);
+
+	crypto_init_queue(&sha_dd->queue, ATMEL_SHA_QUEUE_LENGTH);
+
+	sha_dd->irq = -1;
+
+	/* Get the base address */
+	sha_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!sha_res) {
+		dev_err(dev, "no MEM resource info\n");
+		err = -ENODEV;
+		goto res_err;
+	}
+	sha_dd->phys_base = sha_res->start;
+	sha_phys_size = resource_size(sha_res);
+
+	/* Get the IRQ */
+	sha_dd->irq = platform_get_irq(pdev,  0);
+	if (sha_dd->irq < 0) {
+		dev_err(dev, "no IRQ resource info\n");
+		err = sha_dd->irq;
+		goto res_err;
+	}
+
+	err = request_irq(sha_dd->irq, atmel_sha_irq, IRQF_SHARED, "atmel-sha",
+						sha_dd);
+	if (err) {
+		dev_err(dev, "unable to request sha irq.\n");
+		goto res_err;
+	}
+
+	/* Initializing the clock */
+	sha_dd->iclk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sha_dd->iclk)) {
+		dev_err(dev, "clock intialization failed.\n");
+		err = PTR_ERR(sha_dd->iclk);
+		goto clk_err;
+	}
+
+	sha_dd->io_base = ioremap(sha_dd->phys_base, sha_phys_size);
+	if (!sha_dd->io_base) {
+		dev_err(dev, "can't ioremap\n");
+		err = -ENOMEM;
+		goto sha_io_err;
+	}
+
+	spin_lock(&atmel_sha.lock);
+	list_add_tail(&sha_dd->list, &atmel_sha.dev_list);
+	spin_unlock(&atmel_sha.lock);
+
+	err = atmel_sha_register_algs(sha_dd);
+	if (err)
+		goto err_algs;
+
+	dev_info(dev, "Atmel SHA1/SHA256\n");
+
+	return 0;
+
+err_algs:
+	spin_lock(&atmel_sha.lock);
+	list_del(&sha_dd->list);
+	spin_unlock(&atmel_sha.lock);
+	iounmap(sha_dd->io_base);
+sha_io_err:
+	clk_put(sha_dd->iclk);
+clk_err:
+	free_irq(sha_dd->irq, sha_dd);
+res_err:
+	tasklet_kill(&sha_dd->done_task);
+	kfree(sha_dd);
+	sha_dd = NULL;
+sha_dd_err:
+	dev_err(dev, "initialization failed.\n");
+
+	return err;
+}
+
+static int __devexit atmel_sha_remove(struct platform_device *pdev)
+{
+	static struct atmel_sha_dev *sha_dd;
+
+	sha_dd = platform_get_drvdata(pdev);
+	if (!sha_dd)
+		return -ENODEV;
+	spin_lock(&atmel_sha.lock);
+	list_del(&sha_dd->list);
+	spin_unlock(&atmel_sha.lock);
+
+	atmel_sha_unregister_algs(sha_dd);
+
+	tasklet_kill(&sha_dd->done_task);
+
+	iounmap(sha_dd->io_base);
+
+	clk_put(sha_dd->iclk);
+
+	if (sha_dd->irq >= 0)
+		free_irq(sha_dd->irq, sha_dd);
+
+	kfree(sha_dd);
+	sha_dd = NULL;
+
+	return 0;
+}
+
+static struct platform_driver atmel_sha_driver = {
+	.probe		= atmel_sha_probe,
+	.remove		= __devexit_p(atmel_sha_remove),
+	.driver		= {
+		.name	= "atmel_sha",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(atmel_sha_driver);
+
+MODULE_DESCRIPTION("Atmel SHA1/SHA256 hw acceleration support.");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Nicolas Royer - Eukréa Electromatique");