FPGA device memory is not accessible with ioremap()

[haresh langaraman]

Hi ram,

Can you try to map the address using io_table_init table of kernel
initialization code.

Thanks,
Haresh.
On 27 Dec 2013 05:12, "Sri Ram Vemulpali" <sri.ram.gmu06 at gmail.com> wrote:

> Hi All,
>
> I am using custom board MPC8641d. It has all evaluation board devices
> connected. Apart from that an external FPGA device connected through
> localbus.
>
> The localbus is at address 0xF5005000 directly connected to processor. The
> FPGA address in the processor realm is 0xF3800000. As per spec FPGA target
> interface is CS3 (chip select 3). 32-bit peripheral address bus as seen by
> FPGA is 0xF3800000. The global address of FPGA is 0x0BFC0000.
>
>
> I am implementing driver for FPGA. I am using ioremap() to map to FPGA
> registers at location 0xF3800000. The virtual address returned by ioremap()
> when used with write32(), read32() at memory locations shows no response
> from device. FPGA has special scratch pad to which one can write and read
> to validate the memory map is working. When I write and read I see no value.
>
> #define FCP_ADDRESS_START 0xF3800000
> #define FCP_ADDRESS_END   0xF3808000
> #define FCP_ADDRESS_RANGE (FCP_ADDRESS_END - FCP_ADDRESS_START)
>
>  void *fcp_scratch_pad;
>  char buff[10];
>
>  io_fcp_mem = ioremap_nocache( FCP_ADDRESS_START, FCP_ADDRESS_RANGE );
>
>         if( ! io_fcp_mem ) {
>                 return -ENODEV;
>         }
>
>         printk( KERN_CRIT "ioremap virt mem:%p\n", io_fcp_mem );
>
>         fcp_scratch_pad = ((char*)io_fcp_mem) + 224;
>
>         printk( KERN_CRIT "scratch pad virt mem:%p\n", fcp_scratch_pad );
>
>         iowrite8_rep( fcp_scratch_pad, "Hello", 6 );
>
>         ioread8_rep( fcp_scratch_pad, buff, 6 );
>
>         printk( KERN_CRIT "value read from scratch_pad:%s\n", buff );
>
>         return 0;
>
>
> Attached is the device tree of the board.
>
> Can anyone please direct me or point where I am doing wrong. It seems I am
> unable to access FPGA device memory. Thanks.
>
> --
> Regards,
> Sri.
>
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