/***********************************************************************
 *
 * Copyright (c) 2004	Cucy Systems (http://www.cucy.com)
 * Curt Brune <curt@cucy.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 * Description:   Ethernet interface for Samsung S3C4510B SoC
 */

#include <common.h>
#include <command.h>
#include <net.h>
#include <asm/hardware.h>
#include "s3c4510b_eth.h"

static TX_FrameDescriptor    txFDbase[ETH_MaxTxFrames];
static MACFrame           txFrameBase[ETH_MaxTxFrames];
static RX_FrameDescriptor    rxFDbase[PKTBUFSRX];
static ETH                      m_eth;

static s32 TxFDinit( ETH *eth) {

	s32 i;
	MACFrame *txFrmBase;

	/* disable cache for access to the TX buffers */
	txFrmBase = (MACFrame *)( (u32)txFrameBase | CACHE_DISABLE_MASK);

	/* store start of Tx descriptors and set current */
	eth->m_curTX_FD  =  (TX_FrameDescriptor *) ((u32)txFDbase | CACHE_DISABLE_MASK);
	eth->m_baseTX_FD = eth->m_curTX_FD;

	for ( i = 0; i < ETH_MaxTxFrames; i++) {
		eth->m_baseTX_FD[i].m_frameDataPtr.bf.dataPtr = (u32)&txFrmBase[i];
		eth->m_baseTX_FD[i].m_frameDataPtr.bf.owner   = 0x0; /* CPU owner */
		eth->m_baseTX_FD[i].m_opt.ui                  = 0x0;
		eth->m_baseTX_FD[i].m_status.ui               = 0x0;
		eth->m_baseTX_FD[i].m_nextFD                  = &eth->m_baseTX_FD[i+1];
	}

	/* make the list circular */
	eth->m_baseTX_FD[i-1].m_nextFD          = &eth->m_baseTX_FD[0];

	PUT_REG( REG_BDMATXPTR, (u32)eth->m_curTX_FD);

	return 0;
}

static s32 RxFDinit( ETH *eth) {

	s32 i;
	/*  MACFrame *rxFrmBase; */

	/* disable cache for access to the RX buffers */
	/*  rxFrmBase = (MACFrame *)( (u32)rxFrameBase | CACHE_DISABLE_MASK); */

	/* store start of Rx descriptors and set current */
	eth->m_curRX_FD = (RX_FrameDescriptor *)((u32)rxFDbase | CACHE_DISABLE_MASK);
	eth->m_baseRX_FD = eth->m_curRX_FD;
	for ( i = 0; i < PKTBUFSRX; i++) {
		eth->m_baseRX_FD[i].m_frameDataPtr.bf.dataPtr = (u32)NetRxPackets[i] | CACHE_DISABLE_MASK;
		eth->m_baseRX_FD[i].m_frameDataPtr.bf.owner   = 0x1; /* BDMA owner */
		eth->m_baseRX_FD[i].m_reserved                = 0x0;
		eth->m_baseRX_FD[i].m_status.ui               = 0x0;
		eth->m_baseRX_FD[i].m_nextFD                  = &eth->m_baseRX_FD[i+1];
	}

	/* make the list circular */
	eth->m_baseRX_FD[i-1].m_nextFD                  = &eth->m_baseRX_FD[0];

	PUT_REG( REG_BDMARXPTR, (u32)eth->m_curRX_FD);

	return 0;
}

/*
 * Public u-boot interface functions below
 */

int eth_init(bd_t *bis)
{

	ETH *eth = &m_eth;

	/* store our MAC address */
	eth_getenv_enetaddr("ethaddr", eth->m_mac);

	/* setup DBMA and MAC */
	PUT_REG( REG_BDMARXCON, ETH_BRxRS);   /* reset BDMA RX machine */
	PUT_REG( REG_BDMATXCON, ETH_BTxRS);   /* reset BDMA TX machine */
	PUT_REG( REG_MACCON   , ETH_SwReset); /* reset MAC machine */
	PUT_REG( REG_BDMARXLSZ, sizeof(MACFrame));
	PUT_REG( REG_MACCON   , 0);           /* reset MAC machine */

	/* init frame descriptors */
	TxFDinit( eth);
	RxFDinit( eth);

	/* init the CAM with our MAC address */
	PUT_REG( REG_CAM_BASE,       (eth->m_mac[0] << 24) |
		(eth->m_mac[1] << 16) |
		(eth->m_mac[2] <<  8) |
		(eth->m_mac[3]));
	PUT_REG( REG_CAM_BASE + 0x4, (eth->m_mac[4] << 24) |
		(eth->m_mac[5] << 16));

	/* enable CAM address 1 -- the MAC we just loaded */
	PUT_REG( REG_CAMEN, 0x1);

	PUT_REG( REG_CAMCON,
		ETH_BroadAcc |	/* accept broadcast packetes */
		ETH_CompEn); /* enable compare mode (check against the CAM) */

	/* configure the BDMA Transmitter control */
	PUT_REG( REG_BDMATXCON,
		ETH_BTxBRST   |	/* BDMA Tx burst size 16 words  */
		ETH_BTxMSL110 |	/* BDMA Tx wait to fill 6/8 of the BDMA */
		ETH_BTxSTSKO  |	/* BDMA Tx interrupt(Stop) on non-owner TX FD */
		ETH_BTxEn);	/* BDMA Tx Enable  */

	/* configure the MAC Transmitter control */
	PUT_REG( REG_MACTXCON,
		ETH_EnComp | /* interrupt when the MAC transmits or discards packet */
		ETH_TxEn);	/* MAC transmit enable */

	/* configure the BDMA Receiver control */
	PUT_REG( REG_BDMARXCON,
		ETH_BRxBRST   |	/* BDMA Rx Burst Size 16 words */
		ETH_BRxSTSKO  |	/* BDMA Rx interrupt(Stop) on non-owner RX FD */
		ETH_BRxMAINC  |	/* BDMA Rx Memory Address increment */
		ETH_BRxDIE    |	/* BDMA Rx Every Received Frame Interrupt Enable */
		ETH_BRxNLIE   |	/* BDMA Rx NULL List Interrupt Enable */
		ETH_BRxNOIE   |	/* BDMA Rx Not Owner Interrupt Enable */
		ETH_BRxLittle |	/* BDMA Rx Little endian */
		ETH_BRxEn);	/* BDMA Rx Enable */

	/* configure the MAC Receiver control */
	PUT_REG( REG_MACRXCON,
		ETH_RxEn);	/* MAC ETH_RxEn */

	return 0;

}

/* Send a packet	*/
s32 eth_send(volatile void *packet, s32 length)
{

	u32 i;
	ETH *eth = &m_eth;

	if ( eth->m_curTX_FD->m_frameDataPtr.bf.owner) {
		printf("eth_send(): TX Frame.  CPU not owner.\n");
		return -1;
	}

	/* copy user data into frame data pointer */
	memcpy((void *)((u32)(eth->m_curTX_FD->m_frameDataPtr.bf.dataPtr)),
	       (void *)packet,
	       length);

	/* Set TX Frame flags */
	eth->m_curTX_FD->m_opt.bf.widgetAlign  = 0;
	eth->m_curTX_FD->m_opt.bf.frameDataDir = 1;
	eth->m_curTX_FD->m_opt.bf.littleEndian = 1;
	eth->m_curTX_FD->m_opt.bf.macTxIrqEnbl = 1;
	eth->m_curTX_FD->m_opt.bf.no_crc       = 0;
	eth->m_curTX_FD->m_opt.bf.no_padding   = 0;

	/* Set TX Frame length */
	eth->m_curTX_FD->m_status.bf.len       = length;

	/* Change ownership to BDMA */
	eth->m_curTX_FD->m_frameDataPtr.bf.owner = 1;

	/* Enable MAC and BDMA Tx control register */
	SET_REG( REG_BDMATXCON, ETH_BTxEn);
	SET_REG( REG_MACTXCON,  ETH_TxEn);

	/* poll on TX completion status */
	while ( !eth->m_curTX_FD->m_status.bf.complete) {
		/* sleep  */
		for ( i = 0; i < 0x10000; i ++);
	}

	/* Change the Tx frame descriptor for next use */
	eth->m_curTX_FD = eth->m_curTX_FD->m_nextFD;

	return 0;
}

/* Check for received packets	*/
s32 eth_rx (void)
{
	s32 nLen = 0;
	ETH *eth = &m_eth;

	/* check if packet ready */
	if ( (GET_REG( REG_BDMASTAT)) & ETH_S_BRxRDF) {
		/* process all waiting packets */
		while ( !eth->m_curRX_FD->m_frameDataPtr.bf.owner) {
			nLen = eth->m_curRX_FD->m_status.bf.len;
			/* call back u-boot -- may call eth_send() */
			NetReceive ((u8 *)eth->m_curRX_FD->m_frameDataPtr.ui, nLen);
			/* set owner back to CPU */
			eth->m_curRX_FD->m_frameDataPtr.bf.owner = 1;
			/* clear status */
			eth->m_curRX_FD->m_status.ui = 0x0;
			/* advance to next descriptor */
			eth->m_curRX_FD = eth->m_curRX_FD->m_nextFD;
			/* clear received frame bit */
			PUT_REG( REG_BDMASTAT, ETH_S_BRxRDF);
		}
	}

	return nLen;
}

/* Halt ethernet engine */
void eth_halt(void)
{
	/* disable MAC */
	PUT_REG( REG_MACCON, ETH_HaltReg);
}