//****************************************************************************
//
// Low-Level transmit routine. Should do the actual transmission of the
// packet. The packet is contained in the pbuf that is passed to the function.
// This pbuf might be chained.
//
//****************************************************************************
err_t
low_level_output(struct netif *netif, struct pbuf *p)
{
struct pbuf *q;
int i;
unsigned char *pucBuf;
unsigned long ulTemp;
unsigned char *pucTemp = (unsigned char *)&ulTemp;
//
// Wait for space available in the TX FIFO.
//
while(!EthernetSpaceAvail(ETH_BASE))
{
}
//
// Fill in the first two bytes of the payload data (configured as padding
// with ETH_PAD_SIZE = 2) with the total length of the payload data
// (minus the Ethernet MAC layer header).
//
pucBuf = p->payload;
ulTemp = p->tot_len - 16;
*pucBuf++ = pucTemp[0];
*pucBuf++ = pucTemp[1];
//
// Copy data from the pbuf(s) into the TX Fifo.
// For now, assume every pbuf is full, except possibly the last one.
//
for(q = p; q != NULL; q = q->next)
{
pucBuf = q->payload;
//
// Send the data from the pbuf to the interface, one pbuf at a
// time. The size of the data in each pbuf is kept in the ->len
// variable.
//
for(i = 0; i < q->len; i += 4)
{
pucTemp[0] = *pucBuf++;
pucTemp[1] = *pucBuf++;
pucTemp[2] = *pucBuf++;
pucTemp[3] = *pucBuf++;
HWREG(ETH_BASE + MAC_O_DATA) = ulTemp;
}
}
//
// Wakeup the transmitter.
//
HWREG(ETH_BASE + MAC_O_TR) = MAC_TR_NEWTX;
#if LINK_STATS
lwip_stats.link.xmit++;
#endif
return ERR_OK;
}
//****************************************************************************
//
// Low-Level transmit routine. Should do the actual transmission of the
// packet. The packet is contained in the pbuf that is passed to the function.
// This pbuf might be chained.
//
//****************************************************************************
rt_err_t luminaryif_tx(rt_device_t dev, struct pbuf *p)
{
int iBuf;
unsigned char *pucBuf;
unsigned long *pulBuf;
struct pbuf *q;
int iGather;
unsigned long ulGather;
unsigned char *pucGather;
unsigned long ulTemp;
/* lock tx operation */
rt_sem_take(&tx_sem, RT_WAITING_FOREVER);
//
// Wait for space available in the TX FIFO.
//
while(!EthernetSpaceAvail(ETH_BASE))
{
}
//
// Fill in the first two bytes of the payload data (configured as padding
// with ETH_PAD_SIZE = 2) with the total length of the payload data
// (minus the Ethernet MAC layer header).
//
*((unsigned short *)(p->payload)) = p->tot_len - 16;
//
// Initialize the gather register.
//
iGather = 0;
pucGather = (unsigned char *)&ulGather;
ulGather = 0;
//
// Copy data from the pbuf(s) into the TX Fifo.
//
for(q = p; q != NULL; q = q->next)
{
//
// Intialize a char pointer and index to the pbuf payload data.
//
pucBuf = (unsigned char *)q->payload;
iBuf = 0;
//
// If the gather buffer has leftover data from a previous pbuf
// in the chain, fill it up and write it to the Tx FIFO.
//
while((iBuf < q->len) && (iGather != 0))
{
//
// Copy a byte from the pbuf into the gather buffer.
//
pucGather[iGather] = pucBuf[iBuf++];
//
// Increment the gather buffer index modulo 4.
//
iGather = ((iGather + 1) % 4);
}
//
// If the gather index is 0 and the pbuf index is non-zero,
// we have a gather buffer to write into the Tx FIFO.
//
if((iGather == 0) && (iBuf != 0))
{
HWREG(ETH_BASE + MAC_O_DATA) = ulGather;
ulGather = 0;
}
//
// Copy words of pbuf data into the Tx FIFO, but don't go past
// the end of the pbuf.
//
if((iBuf % 4) != 0)
{
while((iBuf + 4) <= q->len)
{
ulTemp = (pucBuf[iBuf++] << 0);
ulTemp |= (pucBuf[iBuf++] << 8);
ulTemp |= (pucBuf[iBuf++] << 16);
ulTemp |= (pucBuf[iBuf++] << 24);
HWREG(ETH_BASE + MAC_O_DATA) = ulTemp;
}
}
else
{
//
// Initialze a long pointer into the pbuf for 32-bit access.
//
pulBuf = (unsigned long *)&pucBuf[iBuf];
while((iBuf + 4) <= q->len)
{
HWREG(ETH_BASE + MAC_O_DATA) = *pulBuf++;
iBuf += 4;
}
}
//
// Check if leftover data in the pbuf and save it in the gather
// buffer for the next time.
//
while(iBuf < q->len)
{
//
// Copy a byte from the pbuf into the gather buffer.
//
pucGather[iGather] = pucBuf[iBuf++];
//
// Increment the gather buffer index modulo 4.
//
iGather = ((iGather + 1) % 4);
}
}
//
// Send any leftover data to the FIFO.
//
HWREG(ETH_BASE + MAC_O_DATA) = ulGather;
//
// Wakeup the transmitter.
//
HWREG(ETH_BASE + MAC_O_TR) = MAC_TR_NEWTX;
#if LINK_STATS
lwip_stats.link.xmit++;
#endif
return(ERR_OK);
}
