/*
   * 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/init.h>
  #include <linux/errno.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/scatterlist.h>
  #include <linux/dma-mapping.h>
  #include <linux/of_device.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 <linux/platform_data/crypto-atmel.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_SHA224	BIT(19)
  #define SHA_FLAGS_SHA256	BIT(20)
  #define SHA_FLAGS_SHA384	BIT(21)
  #define SHA_FLAGS_SHA512	BIT(22)
  #define SHA_FLAGS_ERROR		BIT(23)
  #define SHA_FLAGS_PAD		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_caps {
  	bool	has_dma;
  	bool	has_dualbuff;
  	bool	has_sha224;
  	bool	has_sha_384_512;
  };
  
  struct atmel_sha_dev;
  
  struct atmel_sha_reqctx {
  	struct atmel_sha_dev	*dd;
  	unsigned long	flags;
  	unsigned long	op;
  
  	u8	digest[SHA512_DIGEST_SIZE] __aligned(sizeof(u32));
  	u64	digcnt[2];
  	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 */
  
  	size_t block_size;
  
  	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	50
  
  struct atmel_sha_dma {
  	struct dma_chan			*chan;
  	struct dma_slave_config dma_conf;
  };
  
  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_dma	dma_lch_in;
  
  	struct atmel_sha_caps	caps;
  
  	u32	hw_version;
  };
  
  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 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 (SHA1/SHA224/SHA256) or 1024 bits (SHA384/SHA512).
   * The bit "1" is appended at the end of the message followed by
   * "padlen-1" zero bits. Then a 64 bits block (SHA1/SHA224/SHA256) or
   * 128 bits block (SHA384/SHA512) equals to the message length in bits
   * is appended.
   *
   * For SHA1/SHA224/SHA256, padlen is calculated as followed:
   *  - if message length < 56 bytes then padlen = 56 - message length
   *  - else padlen = 64 + 56 - message length
   *
   * For SHA384/SHA512, padlen is calculated as followed:
   *  - if message length < 112 bytes then padlen = 112 - message length
   *  - else padlen = 128 + 112 - message length
   */
  static void atmel_sha_fill_padding(struct atmel_sha_reqctx *ctx, int length)
  {
  	unsigned int index, padlen;
  	u64 bits[2];
  	u64 size[2];
  
  	size[0] = ctx->digcnt[0];
  	size[1] = ctx->digcnt[1];
  
  	size[0] += ctx->bufcnt;
  	if (size[0] < ctx->bufcnt)
  		size[1]++;
  
  	size[0] += length;
  	if (size[0]  < length)
  		size[1]++;
  
  	bits[1] = cpu_to_be64(size[0] << 3);
  	bits[0] = cpu_to_be64(size[1] << 3 | size[0] >> 61);
  
  	if (ctx->flags & (SHA_FLAGS_SHA384 | SHA_FLAGS_SHA512)) {
  		index = ctx->bufcnt & 0x7f;
  		padlen = (index < 112) ? (112 - index) : ((128+112) - index);
  		*(ctx->buffer + ctx->bufcnt) = 0x80;
  		memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
  		memcpy(ctx->buffer + ctx->bufcnt + padlen, bits, 16);
  		ctx->bufcnt += padlen + 16;
  		ctx->flags |= SHA_FLAGS_PAD;
  	} else {
  		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, &bits[1], 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
  ",
  		crypto_ahash_digestsize(tfm));
  
  	switch (crypto_ahash_digestsize(tfm)) {
  	case SHA1_DIGEST_SIZE:
  		ctx->flags |= SHA_FLAGS_SHA1;
  		ctx->block_size = SHA1_BLOCK_SIZE;
  		break;
  	case SHA224_DIGEST_SIZE:
  		ctx->flags |= SHA_FLAGS_SHA224;
  		ctx->block_size = SHA224_BLOCK_SIZE;
  		break;
  	case SHA256_DIGEST_SIZE:
  		ctx->flags |= SHA_FLAGS_SHA256;
  		ctx->block_size = SHA256_BLOCK_SIZE;
  		break;
  	case SHA384_DIGEST_SIZE:
  		ctx->flags |= SHA_FLAGS_SHA384;
  		ctx->block_size = SHA384_BLOCK_SIZE;
  		break;
  	case SHA512_DIGEST_SIZE:
  		ctx->flags |= SHA_FLAGS_SHA512;
  		ctx->block_size = SHA512_BLOCK_SIZE;
  		break;
  	default:
  		return -EINVAL;
  		break;
  	}
  
  	ctx->bufcnt = 0;
  	ctx->digcnt[0] = 0;
  	ctx->digcnt[1] = 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)) {
  		if (!dd->caps.has_dma)
  			atmel_sha_write(dd, SHA_IER, SHA_INT_TXBUFE);
  		valmr = SHA_MR_MODE_PDC;
  		if (dd->caps.has_dualbuff)
  			valmr |= SHA_MR_DUALBUFF;
  	} else {
  		atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
  	}
  
  	if (ctx->flags & SHA_FLAGS_SHA1)
  		valmr |= SHA_MR_ALGO_SHA1;
  	else if (ctx->flags & SHA_FLAGS_SHA224)
  		valmr |= SHA_MR_ALGO_SHA224;
  	else if (ctx->flags & SHA_FLAGS_SHA256)
  		valmr |= SHA_MR_ALGO_SHA256;
  	else if (ctx->flags & SHA_FLAGS_SHA384)
  		valmr |= SHA_MR_ALGO_SHA384;
  	else if (ctx->flags & SHA_FLAGS_SHA512)
  		valmr |= SHA_MR_ALGO_SHA512;
  
  	/* Setting CR_FIRST only for the first iteration */
  	if (!(ctx->digcnt[0] || ctx->digcnt[1]))
  		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: 0x%llx 0x%llx, length: %d, final: %d
  ",
  		ctx->digcnt[1], ctx->digcnt[0], length, final);
  
  	atmel_sha_write_ctrl(dd, 0);
  
  	/* should be non-zero before next lines to disable clocks later */
  	ctx->digcnt[0] += length;
  	if (ctx->digcnt[0] < length)
  		ctx->digcnt[1]++;
  
  	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: 0x%llx 0x%llx, length: %d, final: %d
  ",
  		ctx->digcnt[1], ctx->digcnt[0], 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[0] += length1;
  	if (ctx->digcnt[0] < length1)
  		ctx->digcnt[1]++;
  
  	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 void atmel_sha_dma_callback(void *data)
  {
  	struct atmel_sha_dev *dd = data;
  
  	/* dma_lch_in - completed - wait DATRDY */
  	atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
  }
  
  static int atmel_sha_xmit_dma(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);
  	struct dma_async_tx_descriptor	*in_desc;
  	struct scatterlist sg[2];
  
  	dev_dbg(dd->dev, "xmit_dma: digcnt: 0x%llx 0x%llx, length: %d, final: %d
  ",
  		ctx->digcnt[1], ctx->digcnt[0], length1, final);
  
  	if (ctx->flags & (SHA_FLAGS_SHA1 | SHA_FLAGS_SHA224 |
  			SHA_FLAGS_SHA256)) {
  		dd->dma_lch_in.dma_conf.src_maxburst = 16;
  		dd->dma_lch_in.dma_conf.dst_maxburst = 16;
  	} else {
  		dd->dma_lch_in.dma_conf.src_maxburst = 32;
  		dd->dma_lch_in.dma_conf.dst_maxburst = 32;
  	}
  
  	dmaengine_slave_config(dd->dma_lch_in.chan, &dd->dma_lch_in.dma_conf);
  
  	if (length2) {
  		sg_init_table(sg, 2);
  		sg_dma_address(&sg[0]) = dma_addr1;
  		sg_dma_len(&sg[0]) = length1;
  		sg_dma_address(&sg[1]) = dma_addr2;
  		sg_dma_len(&sg[1]) = length2;
  		in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 2,
  			DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
  	} else {
  		sg_init_table(sg, 1);
  		sg_dma_address(&sg[0]) = dma_addr1;
  		sg_dma_len(&sg[0]) = length1;
  		in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 1,
  			DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
  	}
  	if (!in_desc)
  		return -EINVAL;
  
  	in_desc->callback = atmel_sha_dma_callback;
  	in_desc->callback_param = dd;
  
  	atmel_sha_write_ctrl(dd, 1);
  
  	/* should be non-zero before next lines to disable clocks later */
  	ctx->digcnt[0] += length1;
  	if (ctx->digcnt[0] < length1)
  		ctx->digcnt[1]++;
  
  	if (final)
  		dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */
  
  	dd->flags |=  SHA_FLAGS_DMA_ACTIVE;
  
  	/* Start DMA transfer */
  	dmaengine_submit(in_desc);
  	dma_async_issue_pending(dd->dma_lch_in.chan);
  
  	return -EINPROGRESS;
  }
  
  static int atmel_sha_xmit_start(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
  		size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
  {
  	if (dd->caps.has_dma)
  		return atmel_sha_xmit_dma(dd, dma_addr1, length1,
  				dma_addr2, length2, final);
  	else
  		return atmel_sha_xmit_pdc(dd, dma_addr1, length1,
  				dma_addr2, length2, final);
  }
  
  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 + ctx->block_size, DMA_TO_DEVICE);
  	if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
  		dev_err(dd->dev, "dma %u bytes error
  ", ctx->buflen +
  				ctx->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_start(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: 0x%llx 0x%llx, final: %d
  ",
  		 ctx->bufcnt, ctx->digcnt[1], ctx->digcnt[0], 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: 0x%llx 0x%llx, bufcnt: %u, total: %u
  ",
  		ctx->digcnt[1], ctx->digcnt[0], 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, ctx->block_size))
  		/* size is not ctx->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 ctx->block_size aligned */
  			tail = length & (ctx->block_size - 1);
  			length -= tail;
  		}
  	}
  
  	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 & (ctx->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 + ctx->block_size, DMA_TO_DEVICE);
  		if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
  			dev_err(dd->dev, "dma %u bytes error
  ",
  				ctx->buflen + ctx->block_size);
  			return -EINVAL;
  		}
  
  		if (length == 0) {
  			ctx->flags &= ~SHA_FLAGS_SG;
  			count = ctx->bufcnt;
  			ctx->bufcnt = 0;
  			return atmel_sha_xmit_start(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
  ");
  					return -EINVAL;
  			}
  
  			ctx->flags |= SHA_FLAGS_SG;
  
  			count = ctx->bufcnt;
  			ctx->bufcnt = 0;
  			return atmel_sha_xmit_start(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
  ");
  		return -EINVAL;
  	}
  
  	ctx->flags |= SHA_FLAGS_SG;
  
  	/* next call does not fail... so no unmap in the case of error */
  	return atmel_sha_xmit_start(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 + ctx->block_size, DMA_TO_DEVICE);
  		}
  	} else {
  		dma_unmap_single(dd->dev, ctx->dma_addr, ctx->buflen +
  						ctx->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: 0x%llx 0x%llx
  ",
  		ctx->total, ctx->digcnt[1], ctx->digcnt[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: 0x%llx 0%llx
  ",
  			err, ctx->digcnt[1], ctx->digcnt[0]);
  
  	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
  ", 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 (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 if (ctx->flags & SHA_FLAGS_SHA224)
  		for (i = 0; i < SHA224_DIGEST_SIZE / sizeof(u32); i++)
  			hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
  	else if (ctx->flags & SHA_FLAGS_SHA256)
  		for (i = 0; i < SHA256_DIGEST_SIZE / sizeof(u32); i++)
  			hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
  	else if (ctx->flags & SHA_FLAGS_SHA384)
  		for (i = 0; i < SHA384_DIGEST_SIZE / sizeof(u32); i++)
  			hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
  	else
  		for (i = 0; i < SHA512_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 (ctx->flags & SHA_FLAGS_SHA1)
  		memcpy(req->result, ctx->digest, SHA1_DIGEST_SIZE);
  	else if (ctx->flags & SHA_FLAGS_SHA224)
  		memcpy(req->result, ctx->digest, SHA224_DIGEST_SIZE);
  	else if (ctx->flags & SHA_FLAGS_SHA256)
  		memcpy(req->result, ctx->digest, SHA256_DIGEST_SIZE);
  	else if (ctx->flags & SHA_FLAGS_SHA384)
  		memcpy(req->result, ctx->digest, SHA384_DIGEST_SIZE);
  	else
  		memcpy(req->result, ctx->digest, SHA512_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[0] || ctx->digcnt[1])
  		atmel_sha_copy_ready_hash(req);
  
  	dev_dbg(dd->dev, "digcnt: 0x%llx 0x%llx, bufcnt: %d
  ", ctx->digcnt[1],
  		ctx->digcnt[0], 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);
  		dd->flags |= SHA_FLAGS_INIT;
  		dd->err = 0;
  	}
  
  	return 0;
  }
  
  static inline unsigned int atmel_sha_get_version(struct atmel_sha_dev *dd)
  {
  	return atmel_sha_read(dd, SHA_HW_VERSION) & 0x00000fff;
  }
  
  static void atmel_sha_hw_version_init(struct atmel_sha_dev *dd)
  {
  	atmel_sha_hw_init(dd);
  
  	dd->hw_version = atmel_sha_get_version(dd);
  
  	dev_info(dd->dev,
  			"version: 0x%x
  ", dd->hw_version);
  
  	clk_disable_unprepare(dd->iclk);
  }
  
  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
  ",
  						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
  ", 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.
  ",
  				alg_name);
  		return PTR_ERR(tctx->fallback);
  	}
  	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
  				 sizeof(struct atmel_sha_reqctx) +
  				 SHA_BUFFER_LEN + SHA512_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_1_256_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 struct ahash_alg sha_224_alg = {
  	.init		= atmel_sha_init,
  	.update		= atmel_sha_update,
  	.final		= atmel_sha_final,
  	.finup		= atmel_sha_finup,
  	.digest		= atmel_sha_digest,
  	.halg = {
  		.digestsize	= SHA224_DIGEST_SIZE,
  		.base	= {
  			.cra_name		= "sha224",
  			.cra_driver_name	= "atmel-sha224",
  			.cra_priority		= 100,
  			.cra_flags		= CRYPTO_ALG_ASYNC |
  						CRYPTO_ALG_NEED_FALLBACK,
  			.cra_blocksize		= SHA224_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 struct ahash_alg sha_384_512_algs[] = {
  {
  	.init		= atmel_sha_init,
  	.update		= atmel_sha_update,
  	.final		= atmel_sha_final,
  	.finup		= atmel_sha_finup,
  	.digest		= atmel_sha_digest,
  	.halg = {
  		.digestsize	= SHA384_DIGEST_SIZE,
  		.base	= {
  			.cra_name		= "sha384",
  			.cra_driver_name	= "atmel-sha384",
  			.cra_priority		= 100,
  			.cra_flags		= CRYPTO_ALG_ASYNC |
  						CRYPTO_ALG_NEED_FALLBACK,
  			.cra_blocksize		= SHA384_BLOCK_SIZE,
  			.cra_ctxsize		= sizeof(struct atmel_sha_ctx),
  			.cra_alignmask		= 0x3,
  			.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	= SHA512_DIGEST_SIZE,
  		.base	= {
  			.cra_name		= "sha512",
  			.cra_driver_name	= "atmel-sha512",
  			.cra_priority		= 100,
  			.cra_flags		= CRYPTO_ALG_ASYNC |
  						CRYPTO_ALG_NEED_FALLBACK,
  			.cra_blocksize		= SHA512_BLOCK_SIZE,
  			.cra_ctxsize		= sizeof(struct atmel_sha_ctx),
  			.cra_alignmask		= 0x3,
  			.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.
  ");
  		}
  		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_1_256_algs); i++)
  		crypto_unregister_ahash(&sha_1_256_algs[i]);
  
  	if (dd->caps.has_sha224)
  		crypto_unregister_ahash(&sha_224_alg);
  
  	if (dd->caps.has_sha_384_512) {
  		for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++)
  			crypto_unregister_ahash(&sha_384_512_algs[i]);
  	}
  }
  
  static int atmel_sha_register_algs(struct atmel_sha_dev *dd)
  {
  	int err, i, j;
  
  	for (i = 0; i < ARRAY_SIZE(sha_1_256_algs); i++) {
  		err = crypto_register_ahash(&sha_1_256_algs[i]);
  		if (err)
  			goto err_sha_1_256_algs;
  	}
  
  	if (dd->caps.has_sha224) {
  		err = crypto_register_ahash(&sha_224_alg);
  		if (err)
  			goto err_sha_224_algs;
  	}
  
  	if (dd->caps.has_sha_384_512) {
  		for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++) {
  			err = crypto_register_ahash(&sha_384_512_algs[i]);
  			if (err)
  				goto err_sha_384_512_algs;
  		}
  	}
  
  	return 0;
  
  err_sha_384_512_algs:
  	for (j = 0; j < i; j++)
  		crypto_unregister_ahash(&sha_384_512_algs[j]);
  	crypto_unregister_ahash(&sha_224_alg);
  err_sha_224_algs:
  	i = ARRAY_SIZE(sha_1_256_algs);
  err_sha_1_256_algs:
  	for (j = 0; j < i; j++)
  		crypto_unregister_ahash(&sha_1_256_algs[j]);
  
  	return err;
  }
  
  static bool atmel_sha_filter(struct dma_chan *chan, void *slave)
  {
  	struct at_dma_slave	*sl = slave;
  
  	if (sl && sl->dma_dev == chan->device->dev) {
  		chan->private = sl;
  		return true;
  	} else {
  		return false;
  	}
  }
  
  static int atmel_sha_dma_init(struct atmel_sha_dev *dd,
  				struct crypto_platform_data *pdata)
  {
  	int err = -ENOMEM;
  	dma_cap_mask_t mask_in;
  
  	/* Try to grab DMA channel */
  	dma_cap_zero(mask_in);
  	dma_cap_set(DMA_SLAVE, mask_in);
  
  	dd->dma_lch_in.chan = dma_request_slave_channel_compat(mask_in,
  			atmel_sha_filter, &pdata->dma_slave->rxdata, dd->dev, "tx");
  	if (!dd->dma_lch_in.chan) {
  		dev_warn(dd->dev, "no DMA channel available
  ");
  		return err;
  	}
  
  	dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
  	dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
  		SHA_REG_DIN(0);
  	dd->dma_lch_in.dma_conf.src_maxburst = 1;
  	dd->dma_lch_in.dma_conf.src_addr_width =
  		DMA_SLAVE_BUSWIDTH_4_BYTES;
  	dd->dma_lch_in.dma_conf.dst_maxburst = 1;
  	dd->dma_lch_in.dma_conf.dst_addr_width =
  		DMA_SLAVE_BUSWIDTH_4_BYTES;
  	dd->dma_lch_in.dma_conf.device_fc = false;
  
  	return 0;
  }
  
  static void atmel_sha_dma_cleanup(struct atmel_sha_dev *dd)
  {
  	dma_release_channel(dd->dma_lch_in.chan);
  }
  
  static void atmel_sha_get_cap(struct atmel_sha_dev *dd)
  {
  
  	dd->caps.has_dma = 0;
  	dd->caps.has_dualbuff = 0;
  	dd->caps.has_sha224 = 0;
  	dd->caps.has_sha_384_512 = 0;
  
  	/* keep only major version number */
  	switch (dd->hw_version & 0xff0) {
  	case 0x410:
  		dd->caps.has_dma = 1;
  		dd->caps.has_dualbuff = 1;
  		dd->caps.has_sha224 = 1;
  		dd->caps.has_sha_384_512 = 1;
  		break;
  	case 0x400:
  		dd->caps.has_dma = 1;
  		dd->caps.has_dualbuff = 1;
  		dd->caps.has_sha224 = 1;
  		break;
  	case 0x320:
  		break;
  	default:
  		dev_warn(dd->dev,
  				"Unmanaged sha version, set minimum capabilities
  ");
  		break;
  	}
  }
  
  #if defined(CONFIG_OF)
  static const struct of_device_id atmel_sha_dt_ids[] = {
  	{ .compatible = "atmel,at91sam9g46-sha" },
  	{ /* sentinel */ }
  };
  
  MODULE_DEVICE_TABLE(of, atmel_sha_dt_ids);
  
  static struct crypto_platform_data *atmel_sha_of_init(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
  	struct crypto_platform_data *pdata;
  
  	if (!np) {
  		dev_err(&pdev->dev, "device node not found
  ");
  		return ERR_PTR(-EINVAL);
  	}
  
  	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  	if (!pdata) {
  		dev_err(&pdev->dev, "could not allocate memory for pdata
  ");
  		return ERR_PTR(-ENOMEM);
  	}
  
  	pdata->dma_slave = devm_kzalloc(&pdev->dev,
  					sizeof(*(pdata->dma_slave)),
  					GFP_KERNEL);
  	if (!pdata->dma_slave) {
  		dev_err(&pdev->dev, "could not allocate memory for dma_slave
  ");
  		devm_kfree(&pdev->dev, pdata);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	return pdata;
  }
  #else /* CONFIG_OF */
  static inline struct crypto_platform_data *atmel_sha_of_init(struct platform_device *dev)
  {
  	return ERR_PTR(-EINVAL);
  }
  #endif
  
  static int atmel_sha_probe(struct platform_device *pdev)
  {
  	struct atmel_sha_dev *sha_dd;
  	struct crypto_platform_data	*pdata;
  	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.
  ");
  		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
  ");
  		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
  ");
  		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.
  ");
  		goto res_err;
  	}
  
  	/* Initializing the clock */
  	sha_dd->iclk = clk_get(&pdev->dev, "sha_clk");
  	if (IS_ERR(sha_dd->iclk)) {
  		dev_err(dev, "clock intialization failed.
  ");
  		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
  ");
  		err = -ENOMEM;
  		goto sha_io_err;
  	}
  
  	atmel_sha_hw_version_init(sha_dd);
  
  	atmel_sha_get_cap(sha_dd);
  
  	if (sha_dd->caps.has_dma) {
  		pdata = pdev->dev.platform_data;
  		if (!pdata) {
  			pdata = atmel_sha_of_init(pdev);
  			if (IS_ERR(pdata)) {
  				dev_err(&pdev->dev, "platform data not available
  ");
  				err = PTR_ERR(pdata);
  				goto err_pdata;
  			}
  		}
  		if (!pdata->dma_slave) {
  			err = -ENXIO;
  			goto err_pdata;
  		}
  		err = atmel_sha_dma_init(sha_dd, pdata);
  		if (err)
  			goto err_sha_dma;
  
  		dev_info(dev, "using %s for DMA transfers
  ",
  				dma_chan_name(sha_dd->dma_lch_in.chan));
  	}
  
  	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%s%s
  ",
  			sha_dd->caps.has_sha224 ? "/SHA224" : "",
  			sha_dd->caps.has_sha_384_512 ? "/SHA384/SHA512" : "");
  
  	return 0;
  
  err_algs:
  	spin_lock(&atmel_sha.lock);
  	list_del(&sha_dd->list);
  	spin_unlock(&atmel_sha.lock);
  	if (sha_dd->caps.has_dma)
  		atmel_sha_dma_cleanup(sha_dd);
  err_sha_dma:
  err_pdata:
  	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.
  ");
  
  	return err;
  }
  
  static int 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);
  
  	if (sha_dd->caps.has_dma)
  		atmel_sha_dma_cleanup(sha_dd);
  
  	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		= atmel_sha_remove,
  	.driver		= {
  		.name	= "atmel_sha",
  		.owner	= THIS_MODULE,
  		.of_match_table	= of_match_ptr(atmel_sha_dt_ids),
  	},
  };
  
  module_platform_driver(atmel_sha_driver);
  
  MODULE_DESCRIPTION("Atmel SHA (1/256/224/384/512) hw acceleration support.");
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Nicolas Royer - Eukréa Electromatique");