[U-Boot] [PATCH] spi: cadence_qspi: Fix the indirect ahb trigger address setting

[vikasm <vikas.manocha@st.com>]

Hi Stefan,

On 05/28/2015 11:20 PM, Stefan Roese wrote:
> Hi Vikas,
>
> (added Dinh, Graham and Marek to Cc)
>
> On 29.05.2015 03:22, Vikas Manocha wrote:
>> Trigger base address can be set to the spi flash address without any
>> masking, here is the explanation of the register.
>>
>> QSPI_IND_AHB_ADDR_TRIGGER :
>> Trigger Address is the base address that is used by the AHB controller for
>> indirect accesses. When the incoming AHB access address matches a range of
>> addresses from this trigger address to the trigger address + 15, then the AHB
>> request is completed by fetching/storing data from/to the Controllers SRAM.
>>
>> Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
>> ---
>>   drivers/spi/cadence_qspi_apb.c |    7 ++-----
>>   1 file changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
>> index 00a115f..855e5c7 100644
>> --- a/drivers/spi/cadence_qspi_apb.c
>> +++ b/drivers/spi/cadence_qspi_apb.c
>> @@ -50,7 +50,6 @@
>>   #define CQSPI_INST_TYPE_QUAD			(2)
>>
>>   #define CQSPI_STIG_DATA_LEN_MAX			(8)
>> -#define CQSPI_INDIRECTTRIGGER_ADDR_MASK		(0xFFFFF)
>>
>>   #define CQSPI_DUMMY_CLKS_PER_BYTE		(8)
>>   #define CQSPI_DUMMY_BYTES_MAX			(4)
>> @@ -697,8 +696,7 @@ int cadence_qspi_apb_indirect_read_setup(struct cadence_spi_platdata *plat,
>>   		addr_bytes = cmdlen - 1;
>>
>>   	/* Setup the indirect trigger address */
>> -	writel(((u32)plat->ahbbase & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
>> -	       plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
>> +	writel((u32)plat->ahbbase, plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
>>
>>   	/* Configure SRAM partition for read. */
>>   	writel(CQSPI_REG_SRAM_PARTITION_RD, plat->regbase +
>> @@ -798,8 +796,7 @@ int cadence_qspi_apb_indirect_write_setup(struct cadence_spi_platdata *plat,
>>   		return -EINVAL;
>>   	}
>>   	/* Setup the indirect trigger address */
>> -	writel(((u32)plat->ahbbase & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
>> -	       plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
>> +	writel((u32)plat->ahbbase, plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
> Might I ask on which SoC you are using this driver? Which problem are 
> you experiencing exactly?

I am using ST's soc stv0991. The spi flash memory is mapped at address 0x4000_0000. By Masking with 0xF_FFFF, the value to be loaded in the indirect trigger register becomes zero & then spi read/write does not work. By removing or changing the mask to 0xFFFF_FFFF, the loaded value in indirect trigger register is 0x4000_0000 & spi read/write works fine.

It should be same of socfpga also after masking with 0xF_FFFF, wondering how it works there.

No masking is done in the driver while polling fifo for read/write, plat->ahbbase was used directly. Any idea why this masking was done for ahb trigger base register?

Rgds,
Vikas

>
> Graham, can you please comment on this patch?
>
> Thanks,
> Stefan
>
> .
>