FPGA device memory is not accessible with ioremap()

[Sri Ram Vemulpali]

Thank you Srinivas, that was in my mind. I will do that and let you guys
know.

Regards,
Sri.


On Fri, Dec 27, 2013 at 7:34 PM, srinivas bakki <srinivas.bakki at gmail.com>wrote:

> Suggest you to eliminate the problem on the FPGA first. Hook on a scope
> onto the address lines of the FPGA and check whether you get the required
> addresses when you access it. I think there's no reason to doubt ioremap.
>
>
> On Fri, Dec 27, 2013 at 12:22 PM, haresh langaraman <hareshel at gmail.com>wrote:
>
>> 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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>>
>>
>


-- 
Regards,
Sri.
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