/* 
 * Cryptographic API.
 *
 * Support for Infineon DEU hardware crypto engine.
 *
 * Copyright (c) 2005  Johannes Doering <info@com-style.de>, INFINEON
 *
 * modified from crypto/sha1.c
 *  
 * ---------------------------------------------------------------------------
 * Cryptographic API.
 *
 * SHA1 Secure Hash Algorithm.
 *
 * Derived from cryptoapi implementation, adapted for in-place
 * scatterlist interface.
 *
 * Copyright (c) Alan Smithee.
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
 *
 * 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_sha1.c
  \ingroup AMAZON_S_DEU
  \brief sha1 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/mm.h>
#include <linux/crypto.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <asm/scatterlist.h>
#include <asm/byteorder.h>
#include <amazon_s_deu.h>

#define SHA1_DIGEST_SIZE	20
#define SHA1_HMAC_BLOCK_SIZE	64

#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_SHA1
#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 sha1_ctx {
        u64 count;
        u32 state[5];
        u8 buffer[64];
};

extern int disable_deudma;


/*! \fn static void sha1_transform (u32 *state, const u32 *in)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief main interface to sha1 hardware   
    \param state current state 
    \param in 64-byte block of input  
*/                                 
static void sha1_transform (u32 *state, const u32 *in)
{
	int i = 0;
	volatile struct deu_hash_t *hashs = (struct deu_hash_t *) HASH_START;
	unsigned long flag;

	CRTCL_SECT_START;

	for (i = 0; i < 16; i++) {
		hashs->MR = in[i];
	};

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

	CRTCL_SECT_END;
}

/*! \fn static void sha1_init(struct crypto_tfm *tfm)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize sha1 hardware   
    \param tfm linux crypto algo transform  
*/                                 
static void sha1_init(struct crypto_tfm *tfm)
{
	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);

        volatile struct deu_hash_t *hash = (struct deu_hash_t *) HASH_START;
	
	hash->controlr.SM = 1;
	hash->controlr.ALGO = 0;	// 1 = md5  0 = sha1
	hash->controlr.INIT = 1;	// Initialize the hash operation by writing a '1' to the INIT bit.

        sctx->count = 0;
}

/*! \fn static void sha1_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief on-the-fly sha1 computation   
    \param tfm linux crypto algo transform  
    \param data input data  
    \param len size of input data  
*/                                 
static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
			unsigned int len)
{
	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
	unsigned int i, j;

	j = (sctx->count >> 3) & 0x3f;
	sctx->count += len << 3;

	if ((j + len) > 63) {
		memcpy (&sctx->buffer[j], data, (i = 64 - j));
		sha1_transform (sctx->state, (const u32 *)sctx->buffer);
		for (; i + 63 < len; i += 64) {
			sha1_transform (sctx->state, (const u32 *)&data[i]);
		}

		j = 0;
	}
	else
		i = 0;

	memcpy (&sctx->buffer[j], &data[i], len - i);
}

/*! \fn static void sha1_final(struct crypto_tfm *tfm, u8 *out)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief compute final sha1 value   
    \param tfm linux crypto algo transform  
    \param out final md5 output value  
*/                                 
static void sha1_final(struct crypto_tfm *tfm, u8 *out)
{
	struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
	u32 index, padlen;
	u64 t;
	u8 bits[8] = { 0, };
	static const u8 padding[64] = { 0x80, };
	volatile struct deu_hash_t *hashs = (struct deu_hash_t *) HASH_START;
	u32 flag;

	t = sctx->count;
	bits[7] = 0xff & t;
	t >>= 8;
	bits[6] = 0xff & t;
	t >>= 8;
	bits[5] = 0xff & t;
	t >>= 8;
	bits[4] = 0xff & t;
	t >>= 8;
	bits[3] = 0xff & t;
	t >>= 8;
	bits[2] = 0xff & t;
	t >>= 8;
	bits[1] = 0xff & t;
	t >>= 8;
	bits[0] = 0xff & t;

	/* Pad out to 56 mod 64 */
	index = (sctx->count >> 3) & 0x3f;
	padlen = (index < 56) ? (56 - index) : ((64 + 56) - index);
	sha1_update (tfm, padding, padlen);

	/* Append length */
	sha1_update (tfm, bits, sizeof bits);

	CRTCL_SECT_START;

	*((u32 *) out + 0) = hashs->D1R;
	*((u32 *) out + 1) = hashs->D2R;
	*((u32 *) out + 2) = hashs->D3R;
	*((u32 *) out + 3) = hashs->D4R;
	*((u32 *) out + 4) = hashs->D5R;

        CRTCL_SECT_END;

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

struct crypto_alg ifxdeu_sha1_alg = {
	.cra_name	=	"sha1",
	.cra_driver_name=	"ifxdeu-sha1",
	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
	.cra_blocksize	=	SHA1_HMAC_BLOCK_SIZE,
	.cra_ctxsize	=	sizeof(struct sha1_ctx),
	.cra_module	=	THIS_MODULE,
	.cra_alignmask	=	3,
	.cra_list       =       LIST_HEAD_INIT(ifxdeu_sha1_alg.cra_list),
	.cra_u		=	{ .digest = {
	.dia_digestsize	=	SHA1_DIGEST_SIZE,
	.dia_init   	= 	sha1_init,
	.dia_update 	=	sha1_update,
	.dia_final  	=	sha1_final } }
};

/*! \fn int __init ifxdeu_init_sha1 (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize sha1 driver    
*/                                 
int __init ifxdeu_init_sha1 (void)
{
	int ret;

	if ((ret = crypto_register_alg(&ifxdeu_sha1_alg)))
		goto sha1_err;

	CRTCL_SECT_INIT;

	printk (KERN_NOTICE "IFX DEU SHA1 initialized%s.\n", disable_deudma ? "" : " (DMA)");
	return ret;

sha1_err:
	printk(KERN_ERR "IFX DEU SHA1 initialization failed!\n");
	return ret;
}

/*! \fn void __exit ifxdeu_fini_sha1 (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief unregister sha1 driver   
*/                                 
void __exit ifxdeu_fini_sha1 (void)
{
	crypto_unregister_alg (&ifxdeu_sha1_alg);
}