[ts-7000] Re: DMA with SSP on TS7400

["pakorn_0608" <>]

Unfortunately for me,I test it more and check in deep.
Both of SSPTx and SSPRx are sometime update, not only one like i said before.

For ts7400,I use virt_to_bus only for address that i got from "kmalloc", for 
SSPDR -address for SSPTX and SSPRx-, I doesn't use it.

On the morning,I tried to use it with SSPDR. There is nothing comtout from SSP.
I thoght address of SSPDR is physical addresses by default for EP9302 on TS7400.

I try to use bus_to_virt with the memory that use for keeping data from SSPRx. 
It's the same result.

Anyway,Thanks so much, I learn a lot from you.

Now i looking for mor information about flush cache cpu which another one tell 
me in another replying.

I'm just read from a bit and it seem have a useful for me.
I'll try and update to you again if any progress.


--- In  Abid Rashid <> wrote:
>
> Â 
> It is important to map virtual addresses to physical addresses whenever you 
> work with DMA. (Please note that virt_to_bus might restrict your cross 
> platform portability).
> I am not sure which Addresses are you using for Rx. 
>
> Make sure you have mapped your DMA virtual addresses to Rx bus addresses 
> and vice versa.U might use bus_to_virt on DMA Rx addresses and use this 
> address to look at the data.
> If any thing else I cant help....
> Â 
> br,
> Abid
> --- On Mon, 3/15/10, pakorn_0608 <> wrote:
>
>
> From: pakorn_0608 <>
> Subject: [ts-7000] Re: DMA with SSP on TS7400
> To: 
> Date: Monday, March 15, 2010, 11:31 PM
>
>
> Â 
>
>
>
> Thanks a lot, Abid :-)
>
> The virt_to_bus it's work for me.
> bit by bit between SSPtx and SSP_CLK is come out correctly, but, i have new 
> problem now.
>
> Only SSPTx right , SSPRx is sometime right.
> I use printk" for show what i got from SSPRx by using DMA.
> On start up module,after enable DMA, the memory of SSPRx that i allocate for 
> DMA, It's sometime show my default value which i set it up on initial, but, 
> sometime it show correct value follow by what it get from SSPRx.
>
> I'm finding the way to solve it.
> Could you have any suggestion to me?
>
> Pakorn
>
> --- In  .com, Abid Rashid <abidrashid24@ ...> wrote:
> >
> > � 
> > Kmalloc returned addresses need to be mapped to the bus addresses.
> > Use
> > bus_addr = virt_to_bus( virt_addr/ *returned from kmalloc*/);
> > address as the dma destination.
> > Hope it would help
> > br,
> > Abid
> >
> > --- On Mon, 3/15/10, pakorn_0608 <pakorn_0608@ ...> wrote:
> >
> >
> > From: pakorn_0608 <pakorn_0608@ ...>
> > Subject: [ts-7000] DMA with SSP on TS7400
> > To:  .com
> > Date: Monday, March 15, 2010, 3:21 AM
> >
> >
> > � 
> >
> >
> >
> > Dear members,
> >
> > I'm use DMA on M2M mode with SSP, both of SSPTx and SSPRx for each channel.
> >
> > I have a bit problem with data that transmit and receive from SSP.
> >
> > I use "kmalloc" to get allocate memory address and i write some data into 
> > that address.
> > I can write and read correctly by using "printk".
> >
> > I'm also use it with SSPDR for transmit data from SPI by "outl" command, 
> > data come out from SSPTx with clock sync correctly.
> >
> > Anyway,It's wrong when i'm using with DMA register.
> >
> > For example, DMA M2M0 using with SSPtx, I set DMA register, source register 
> > with address from kmalloc "0xd120_10eo" , destination address SSPDR 
> > "0x808A_0008" and BCR by 3.
> >
> > There are data come out from SSPtx but it is not right value that it should 
> > be in memory address shown by "printk".
> >
> > Could someone have some suggest to me for using DMA with SSP for 7400 board?
> >
> > ************ *******
> > example with some coding:
> > ************ *******
> >
> > /* I write it for kernel module*/
> > ...
> > char *buffer_dma[ MAX_EP93XX_ DMA_M2M_CHANNELS ];
> > .
> > .
> > .
> > buffer_dma[0] = kmalloc( size , GFP_KERNEL|GFP_ DMA); /* example size is 
> > 10*/
> >
> > for(i=0;i<10; i++)
> > {
> > buffer_dma[0] [i] = i*10;
> >
> > printk("Address of buffer_dma[0] [%d] = 0x%lx\n",i,( unsigned long)&buffer_ 
> > dma[0][i] );
> > printk("Value of buffer_dma[0] [%d] = %d\n",i,buffer_ dma[0][i] );
> > }
> >
> > /*
> > I print this value for show address and value
> > my address for buffer_dma[0] [0] is "0xd120_10eo" and value is 0
> > next, address for buffer_dma[0] [1] is "0xd120_10e1" and value is 10... and 
> > other value is shown correctly.
> >
> > I also use with SSP
> >
> > */
> >
> > for(i=0;i<10; i++)
> > {
> > outl(buffer_ dma[0][i] , SSPDR );
> > }
> >
> > /*
> > I'm set SSP 8 bit,
> > data come out from SSPTx is correctly , compare bit by bit with ssp_clock
> >
> > next i'm usongit with DMA M2M for SSPTx
> >
> > */
> >
> > outl(&buffer_ dma[0][0] , m2m_channel[ channel]. base + M2M_SAR_BASE0) ;
> > outl( SSPDR , m2m_channel[ channel]. base + M2M_DAR_BASE0) ;
> > outl(3 , m2m_channel[ channel]. base + M2M_BCR0);
> >
> > /*
> > After that i'm enable DMA
> > my data that come out from SSPTx is wrong all,
> > even i change data in my buffer_dma[0] [i] on above
> > data come out from SSPTx is still the same value.
> > It's not match with it should be in memory address
> > */
> >
>




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