/* 
 * Cryptographic API.
 *
 * Support for Infineon DEU hardware crypto engine.
 *
 * Copyright (c) 2005  Johannes Doering <info@com-style.de>, INFINEON
 *
 * modified from crypto/md5.c
 *  
 * ---------------------------------------------------------------------------
 * Cryptographic API.
 *
 * MD5 Message Digest Algorithm (RFC1321).
 *
 * Derived from cryptoapi implementation, originally based on the
 * public domain implementation written by Colin Plumb in 1993.
 *
 * Copyright (c) Cryptoapi developers.
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 * ---------------------------------------------------------------------------
 ** HISTORY
 ** $Date        $Author  	$Comment
 * --------------------------------------------------------------------------- 
 */

/**
  \addtogroup AMAZON_S_DEU
  \ingroup AMAZON_S_BSP
  \brief amazon_s deu driver module
*/

/*!
  \file amazon_s_deu_md5.c
  \ingroup AMAZON_S_DEU
  \brief md5 driver file
*/

/*!
  \addtogroup AMAZON_S_DEU_FUNCTIONS
  \ingroup AMAZON_S_DEU
  \brief amazon_s deu driver functions
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <linux/types.h>
#include <asm/byteorder.h>
#include <amazon_s_deu.h>

#define MD5_DIGEST_SIZE		16
#define MD5_HMAC_BLOCK_SIZE	64
#define MD5_BLOCK_WORDS		16
#define MD5_HASH_WORDS		4

#if 0
     #define CRTCL_SECT_INIT        
     #define CRTCL_SECT_START       local_irq_save(flag)
     #define CRTCL_SECT_END         local_irq_restore(flag)
#else
     static spinlock_t lock;
     #define CRTCL_SECT_INIT        spin_lock_init(&lock)
     #define CRTCL_SECT_START       spin_lock_irqsave(&lock, flag)
     #define CRTCL_SECT_END         spin_unlock_irqrestore(&lock, flag)
#endif

//#define CRYPTO_DEBUG
#ifdef CRYPTO_DEBUG
extern char debug_level;
#define DPRINTF(level, format, args...)	if (level < debug_level) printk(KERN_INFO "[%s %s %d]: " format, __FILE__, __func__, __LINE__, ##args);
#else
#define DPRINTF(level, format, args...)
#endif

#ifdef CONFIG_CRYPTO_DEV_AMAZON_S_MD5
#include <amazon_s.h>
#include <amazon_s_deu_structs.h>
#define HASH_START   AMAZON_S_HASH_CON
#endif
#ifdef CONFIG_CRYPTO_DEV_AMAZON_S_DMA
#include <amazon_s_deu_dma.h>
#include <amazon_s_dma.h>
#include <irq.h>
#endif

struct md5_ctx {
	u32 hash[MD5_HASH_WORDS];
	u32 block[MD5_BLOCK_WORDS];
	u64 byte_count;
};

extern int disable_deudma;

/*! \fn static u32 endian_swap(u32 input)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief perform dword level endian swap   
    \param input value of dword that requires to be swapped  
*/ 
static u32 endian_swap(u32 input)
{
    u8 *ptr = (u8 *)&input;
    
    return ((ptr[3] << 24) | (ptr[2] << 16) | (ptr[1] << 8) | ptr[0]);     
}

/*! \fn static void md5_transform(u32 *hash, u32 const *in)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief main interface to md5 hardware   
    \param hash current hash value  
    \param in 64-byte block of input  
*/                                 
static void md5_transform(u32 *hash, u32 const *in)
{
        int i;
	volatile struct deu_hash_t *hashs = (struct deu_hash_t *) HASH_START;
	unsigned long flag;

	CRTCL_SECT_START;

	for (i = 0; i < 16; i++) {
	        //printk("in[%d] = %08x\n", i, endian_swap(in[i]));
		hashs->MR = endian_swap(in[i]);
	};

	//wait for processing
	while (hashs->controlr.BSY) {
		// this will not take long
	}

	CRTCL_SECT_END;
}

/*! \fn static inline void md5_transform_helper(struct md5_ctx *ctx)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief interfacing function for md5_transform()   
    \param ctx crypto context  
*/                                 
static inline void md5_transform_helper(struct md5_ctx *ctx)
{
	//le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
	md5_transform(ctx->hash, ctx->block);
}

/*! \fn static void md5_init(struct crypto_tfm *tfm)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize md5 hardware   
    \param tfm linux crypto algo transform  
*/                                 
static void md5_init(struct crypto_tfm *tfm)
{
	struct md5_ctx *mctx = crypto_tfm_ctx(tfm);
        volatile struct deu_hash_t *hash = (struct deu_hash_t *) HASH_START;

	hash->controlr.SM = 1;
	hash->controlr.ALGO = 1;	// 1 = md5  0 = sha1
	hash->controlr.INIT = 1;	// Initialize the hash operation by writing a '1' to the INIT bit.

	mctx->byte_count = 0;
}

/*! \fn static void md5_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief on-the-fly md5 computation   
    \param tfm linux crypto algo transform  
    \param data input data  
    \param len size of input data  
*/                                 
static void md5_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
{
	struct md5_ctx *mctx = crypto_tfm_ctx(tfm);
	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);

	mctx->byte_count += len;

	if (avail > len) {
		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
		       data, len);
		return;
	}

	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
	       data, avail);

	md5_transform_helper(mctx);
	data += avail;
	len -= avail;

	while (len >= sizeof(mctx->block)) {
		memcpy(mctx->block, data, sizeof(mctx->block));
		md5_transform_helper(mctx);
		data += sizeof(mctx->block);
		len -= sizeof(mctx->block);
	}

	memcpy(mctx->block, data, len);
}

/*! \fn static void md5_final(struct crypto_tfm *tfm, u8 *out)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief compute final md5 value   
    \param tfm linux crypto algo transform  
    \param out final md5 output value  
*/                                 
static void md5_final(struct crypto_tfm *tfm, u8 *out)
{
	struct md5_ctx *mctx = crypto_tfm_ctx(tfm);
	const unsigned int offset = mctx->byte_count & 0x3f;
	char *p = (char *)mctx->block + offset;
	int padding = 56 - (offset + 1);
	volatile struct deu_hash_t *hashs = (struct deu_hash_t *) HASH_START;
	u32 flag;

	*p++ = 0x80;
	if (padding < 0) {
		memset(p, 0x00, padding + sizeof (u64));
		md5_transform_helper(mctx);
		p = (char *)mctx->block;
		padding = 56;
	}

	memset(p, 0, padding);
	mctx->block[14] = endian_swap(mctx->byte_count << 3);
	mctx->block[15] = endian_swap(mctx->byte_count >> 29);

#if 0
	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
	                  sizeof(u64)) / sizeof(u32));
#endif

	md5_transform(mctx->hash, mctx->block);

	//cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
	//memcpy(out, mctx->hash, sizeof(mctx->hash));

	CRTCL_SECT_START;

	*((u32 *) out + 0) = endian_swap (hashs->D1R);
	*((u32 *) out + 1) = endian_swap (hashs->D2R);
	*((u32 *) out + 2) = endian_swap (hashs->D3R);
	*((u32 *) out + 3) = endian_swap (hashs->D4R);

	CRTCL_SECT_END;

	// Wipe context
	memset(mctx, 0, sizeof(*mctx));
}

static struct crypto_alg ifxdeu_md5_alg = {
	.cra_name	        =	"md5",
	.cra_driver_name	=	"ifxdeu-md5",
	.cra_flags	        =	CRYPTO_ALG_TYPE_DIGEST,
	.cra_blocksize	        =	MD5_HMAC_BLOCK_SIZE,
	.cra_ctxsize	        =	sizeof(struct md5_ctx),
	.cra_module	        =	THIS_MODULE,
	.cra_list	        =	LIST_HEAD_INIT(ifxdeu_md5_alg.cra_list),
	.cra_u		        =	{ .digest = {
	.dia_digestsize	        =	MD5_DIGEST_SIZE,
	.dia_init   	        = 	md5_init,
	.dia_update 	        =	md5_update,
	.dia_final  	        =	md5_final } }
};

/*! \fn int __init ifxdeu_init_md5 (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize md5 driver   
*/                                 
int __init ifxdeu_init_md5 (void)
{
	int ret;

	if ((ret = crypto_register_alg(&ifxdeu_md5_alg)))
		goto md5_err;

	CRTCL_SECT_INIT;

	printk (KERN_NOTICE "IFX DEU MD5 initialized%s.\n", disable_deudma ? "" : " (DMA)");
	return ret;

md5_err:
	printk(KERN_ERR "IFX DEU MD5 initialization failed!\n");
	return ret;
}

/*! \fn void __exit ifxdeu_fini_md5 (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief unregister md5 driver   
*/                                 
void __exit ifxdeu_fini_md5 (void)
{
	crypto_unregister_alg (&ifxdeu_md5_alg);
}