FPGA device memory is not accessible with ioremap()

Sri Ram Vemulpali sri.ram.gmu06 at gmail.com
Fri Dec 27 01:41:41 EST 2013


Haresh,

iotable_init() is specific to ARM arch. I am using powerpc, seems there is
no equivalent to that static function. Can you please give more input.

Thanks,
Sri.


On Thu, Dec 26, 2013 at 9:01 PM, Sri Ram Vemulpali
<sri.ram.gmu06 at gmail.com>wrote:

> Thanks for reply Haresh. Will try and let u know.
>
> Thanks,
> Sri
>
>
> On Thu, Dec 26, 2013 at 5:09 PM, haresh langaraman <hareshel at gmail.com>wrote:
>
>> 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.
>>>
>>> _______________________________________________
>>> Kernelnewbies mailing list
>>> Kernelnewbies at kernelnewbies.org
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>>>
>>>
>
>
> --
> Regards,
> Sri.
>



-- 
Regards,
Sri.
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