PCI DMA memory-to-memory transfer

[munees waran <munees40@xxxxxxxxxxx>]

Hi,

 

I want to do memory-to-memory data transfer using dma controller 8237.

 

I configured channel 0 as read and channel 1 as write one. After that i wrote data pattern at address "phys". Using dma, i am transferring data from address "phys" to "tphys". I used get_dma_residue() to know the status. It is always 5 only. Pls help me to resolve this issue.

 

/*** DMA Mode Register ***/
#define DMA_PCI_NRZ_READ 0x88
#define DMA_PCI_NRZ_WRITE 0x85

#define MEM_TO_MEM_ENABLE 0x01

#define DREQ_CH_ONE   0x04
#define DREQ_CH_TWO   0x05

#define CHANNEL_ZERO        0x00
#define CHANNEL_ONE         0x01

#define SET_CH1_MASK  0x04
#define SET_CH2_MASK  0x05

 

flags = claim_dma_lock();

/** Clear the status bits ***/

get = dma_inb(DMA1_STAT_REG);

printk("status bits %d\n", get);

/** Disable DMA while configuring **/

disable_dma(card->writechannel);

set_dma_mode(card->writechannel, DMA_PCI_NRZ_WRITE);

clear_dma_ff(card->writechannel);

printk("tphys %ld\n", tphys);

set_dma_addr(card->writechannel, tphys); //card->chandma + 210);

set_dma_count(card->writechannel, 5);

/*** Configure the DMA channel 0 as read channel **/

disable_dma(card->readchannel);

set_dma_mode(card->readchannel, DMA_PCI_NRZ_READ);

clear_dma_ff(card->readchannel);

printk("phys %ld\n", phys);

set_dma_addr(card->readchannel, phys); //card->chandma);

set_dma_count(card->readchannel, 5);

/**** Configure DMA command register for mem-to-mem transfer **/

data = "">

printk("value of cmd reg, b %d\n", data);

data = "" | MEM_TO_MEM_ENABLE;

printk("value of data cmd %d\n", data);

outb(data, DMA1_CMD_REG);

data = "">

printk("value of cmd reg, a %d\n", data);

data = "">

printk("REQ reg,b %d\n", data);

outb(0x04, DMA1_REQ_REG);

outb(0x05, DMA1_REQ_REG);

data = "">

printk("REQ reg,a %d\n", data);

/** Enable DMA operation ***/

enable_dma(card->writechannel);

enable_dma(card->readchannel);

/*** Release the lock **/

release_dma_lock(flags);

 

Thanks & Regards,

Munees.

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