void mite_prep_dma(struct mite_channel *mite_chan,
unsigned int num_device_bits, unsigned int num_memory_bits)
{
unsigned int chor, chcr, mcr, dcr, lkcr;
struct mite_struct *mite = mite_chan->mite;
MDPRINTK("mite_prep_dma ch%i\n", mite_chan->channel);
/* reset DMA and FIFO */
chor = CHOR_DMARESET | CHOR_FRESET;
writel(chor, mite->mite_io_addr + MITE_CHOR(mite_chan->channel));
/* short link chaining mode */
chcr = CHCR_SET_DMA_IE | CHCR_LINKSHORT | CHCR_SET_DONE_IE |
CHCR_BURSTEN;
/*
* Link Complete Interrupt: interrupt every time a link
* in MITE_RING is completed. This can generate a lot of
* extra interrupts, but right now we update the values
* of buf_int_ptr and buf_int_count at each interrupt. A
* better method is to poll the MITE before each user
* "read()" to calculate the number of bytes available.
*/
chcr |= CHCR_SET_LC_IE;
if (num_memory_bits == 32 && num_device_bits == 16) {
/* Doing a combined 32 and 16 bit byteswap gets the 16 bit samples into the fifo in the right order.
Tested doing 32 bit memory to 16 bit device transfers to the analog out of a pxi-6281,
which has mite version = 1, type = 4. This also works for dma reads from the counters
on e-series boards. */
chcr |= CHCR_BYTE_SWAP_DEVICE | CHCR_BYTE_SWAP_MEMORY;
}
if (mite_chan->dir == COMEDI_INPUT) {
chcr |= CHCR_DEV_TO_MEM;
}
writel(chcr, mite->mite_io_addr + MITE_CHCR(mite_chan->channel));
/* to/from memory */
mcr = CR_RL(64) | CR_ASEQUP;
switch (num_memory_bits) {
case 8:
mcr |= CR_PSIZE8;
break;
case 16:
mcr |= CR_PSIZE16;
break;
case 32:
mcr |= CR_PSIZE32;
break;
default:
rt_printk
("mite: bug! invalid mem bit width for dma transfer\n");
break;
}
writel(mcr, mite->mite_io_addr + MITE_MCR(mite_chan->channel));
/* from/to device */
dcr = CR_RL(64) | CR_ASEQUP;
dcr |= CR_PORTIO | CR_AMDEVICE | CR_REQSDRQ(mite_chan->channel);
switch (num_device_bits) {
case 8:
dcr |= CR_PSIZE8;
break;
case 16:
dcr |= CR_PSIZE16;
break;
case 32:
dcr |= CR_PSIZE32;
break;
default:
rt_printk
("mite: bug! invalid dev bit width for dma transfer\n");
break;
}
writel(dcr, mite->mite_io_addr + MITE_DCR(mite_chan->channel));
/* reset the DAR */
writel(0, mite->mite_io_addr + MITE_DAR(mite_chan->channel));
/* the link is 32bits */
lkcr = CR_RL(64) | CR_ASEQUP | CR_PSIZE32;
writel(lkcr, mite->mite_io_addr + MITE_LKCR(mite_chan->channel));
/* starting address for link chaining */
writel(mite_chan->ring->descriptors_dma_addr,
mite->mite_io_addr + MITE_LKAR(mite_chan->channel));
MDPRINTK("exit mite_prep_dma\n");
}
void mite_prep_dma(struct mite_channel *mite_chan,
unsigned int num_device_bits, unsigned int num_memory_bits)
{
unsigned int chor, chcr, mcr, dcr, lkcr;
struct mite_struct *mite = mite_chan->mite;
MDPRINTK("mite_prep_dma ch%i\n", mite_chan->channel);
chor = CHOR_DMARESET | CHOR_FRESET;
writel(chor, mite->mite_io_addr + MITE_CHOR(mite_chan->channel));
chcr = CHCR_SET_DMA_IE | CHCR_LINKSHORT | CHCR_SET_DONE_IE |
CHCR_BURSTEN;
chcr |= CHCR_SET_LC_IE;
if (num_memory_bits == 32 && num_device_bits == 16) {
chcr |= CHCR_BYTE_SWAP_DEVICE | CHCR_BYTE_SWAP_MEMORY;
}
if (mite_chan->dir == COMEDI_INPUT)
chcr |= CHCR_DEV_TO_MEM;
writel(chcr, mite->mite_io_addr + MITE_CHCR(mite_chan->channel));
mcr = CR_RL(64) | CR_ASEQUP;
switch (num_memory_bits) {
case 8:
mcr |= CR_PSIZE8;
break;
case 16:
mcr |= CR_PSIZE16;
break;
case 32:
mcr |= CR_PSIZE32;
break;
default:
printk(KERN_WARNING "mite: bug! invalid mem bit width for dma "
"transfer\n");
break;
}
writel(mcr, mite->mite_io_addr + MITE_MCR(mite_chan->channel));
dcr = CR_RL(64) | CR_ASEQUP;
dcr |= CR_PORTIO | CR_AMDEVICE | CR_REQSDRQ(mite_chan->channel);
switch (num_device_bits) {
case 8:
dcr |= CR_PSIZE8;
break;
case 16:
dcr |= CR_PSIZE16;
break;
case 32:
dcr |= CR_PSIZE32;
break;
default:
printk(KERN_WARNING "mite: bug! invalid dev bit width for dma "
"transfer\n");
break;
}
writel(dcr, mite->mite_io_addr + MITE_DCR(mite_chan->channel));
writel(0, mite->mite_io_addr + MITE_DAR(mite_chan->channel));
lkcr = CR_RL(64) | CR_ASEQUP | CR_PSIZE32;
writel(lkcr, mite->mite_io_addr + MITE_LKCR(mite_chan->channel));
writel(mite_chan->ring->descriptors_dma_addr,
mite->mite_io_addr + MITE_LKAR(mite_chan->channel));
MDPRINTK("exit mite_prep_dma\n");
}
