[U-Boot] [UBOOT][PATCHv4 3/6] driver: mtd: spi: Add memory mapped read support

[Sourav Poddar <sourav.poddar@ti.com>]

On Saturday 05 October 2013 01:36 AM, Jagan Teki wrote:
> Please use the commit msg head as "sf: .."
Ok.
> On Fri, Oct 4, 2013 at 8:21 PM, Sourav Poddar<sourav.poddar@ti.com>  wrote:
>> Qspi controller can have a memory mapped port which can be used for
>> data read. Added support to enable memory mapped port read.
>>
>> This patch enables the following:
>> - It enables exchange of memory map address between mtd and qspi
>> through the introduction of "memory_map" flag.
>> - Add support to communicate to the driver that memory mapped
>>   transfer is to be started through introduction of new flags like
>> "SPI_XFER_MEM_MAP" and "SPI_XFER_MEM_MAP_END".
>>
>> This will enable the spi controller to do memory mapped configurations
>> if required.
>>
>> Signed-off-by: Sourav Poddar<sourav.poddar@ti.com>
>> ---
>>   drivers/mtd/spi/sf_ops.c   |    2 ++
>>   drivers/mtd/spi/sf_probe.c |    1 +
>>   include/spi.h              |    3 +++
>>   3 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
>> index c009af5..bee4128 100644
>> --- a/drivers/mtd/spi/sf_ops.c
>> +++ b/drivers/mtd/spi/sf_ops.c
>> @@ -269,7 +269,9 @@ int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
>>
>>          /* Handle memory-mapped SPI */
>>          if (flash->memory_map) {
>> +               spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP);
>>                  memcpy(data, flash->memory_map + offset, len);
>> +               spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP);
> Is it correct, can you check it once.
> where is SPI_XFER_MEM_MAP_END used?
It will be used in the driver. check 4/6 patch of this series.
> Looks like you have used mem-map for only reads is it? if so where is
> SPI_XFER_BEGIN is using?
Yes, only memory mapped read is supported.

Ideally, we dont need BEGIN flag for memory mapped cases. I have 
explained a bit
more on your similar comment on patch 4/6.
> Please use _MMAP instead of _MEM_MAP for simple naming convention.
>
OK.