FPGA device memory is not accessible with ioremap()

[haresh langaraman]

Is there any way to specify in power pc that we can make static physical to
virtual mapping which is similar to io_table_init in ARM?

choose the virtual address and map to FPGA physical address using mapping
function similar to io_table_init? I am hoping that it has to be there
because your platform driver requires to access the board's registers using
it.

have you tried using io_remap alone instead of io_remap_nocahe?

or just to try

write a user space application with mmap to this address and try to see
whether you are able to read scratch regs?



On Fri, Dec 27, 2013 at 12:11 PM, Sri Ram Vemulpali <sri.ram.gmu06 at gmail.com
> wrote:

> 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
>>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>>>
>>>>
>>
>>
>> --
>> Regards,
>> Sri.
>>
>
>
>
> --
> Regards,
> Sri.
>
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