On 5 August 2015 at 07:35, Vignesh R [off-list ref] wrote:

On 08/05/2015 10:51 AM, Michal Suchanek wrote:

quoted

Hello,

On 4 August 2015 at 19:59, R, Vignesh [off-list ref] wrote:

quoted

On 8/4/2015 9:21 PM, Mark Brown wrote:

quoted

On Mon, Aug 03, 2015 at 10:27:19AM +0530, Vignesh R wrote:

quoted

quoted

TI QSPI controller has two blocks:
1. SPI_CORE: This is generic(normal) spi mode. This can be used to
communicate with any SPI devices (serial flashes as well as non-flash
devices like touchscreen).
2. SFI_MM_IF(SPI memory mapped interface): The SFI_MM_IF block only
allows reading and writing to an SPI flash device only. Used to speed up
flash reads. It _cannot_ be used to communicate with non flash devices.
Now, the spi_message that ti-qspi receives in transfer_one() callback
can be from mtd device(in which case SFI_MM_IF can be used) or from any
other non flash SPI device (in which case SFI_MM_IF must not be used
instead SPI_CORE is to be used) but there is no way(is there?) to
distinguish where spi_message is from. Therefore I introduced flag
(use_mmap_mode) to struct spi_message. mtd driver will set flag to true,
this helps the ti-qspi driver to determine that the user is flash device
and thus can do read via SFI_MM_IF. If this flag is not set then the
user is assumed to be non flash SPI driver and will use SPI_CORE block
to communicate.

On the whole, I just need a way to determine that the user is a flash
device in order to switch to memory mapped interface.

Maybe it can be set on the SPI slave rather than each message.

You mean to add flag to spi_device struct? That's ok for me.

There are already mode flags so you can just add one more.

Thanks

Michal
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