On 5 August 2015 at 07:35, Vignesh R <vigneshr@xxxxxx> wrote: > > > On 08/05/2015 10:51 AM, Michal Suchanek wrote: >> Hello, >> >> On 4 August 2015 at 19:59, R, Vignesh <vigneshr@xxxxxx> wrote: >>> >>> >>> On 8/4/2015 9:21 PM, Mark Brown wrote: >>>> On Mon, Aug 03, 2015 at 10:27:19AM +0530, Vignesh R wrote: >>>> >>> >>> 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
