Contains documentation and testing details for qspi flash interface.
Signed-off-by: Sourav Poddar sourav.poddar@ti.com --- v4->v5: - Move the doc to doc/SPI - testing details formatted to actual testing logs done on the board. doc/SPI/README.ti_qspi_dra_test | 48 +++++++++++++++++++++++++++++++++++++++ doc/SPI/README.ti_qspi_flash | 47 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 95 insertions(+), 0 deletions(-) create mode 100644 doc/SPI/README.ti_qspi_dra_test create mode 100644 doc/SPI/README.ti_qspi_flash
diff --git a/doc/SPI/README.ti_qspi_dra_test b/doc/SPI/README.ti_qspi_dra_test new file mode 100644 index 0000000..fe37857 --- /dev/null +++ b/doc/SPI/README.ti_qspi_dra_test @@ -0,0 +1,48 @@ +------------------------------------------------- + Simple steps used to test the QSPI at U-Boot +------------------------------------------------- + +For #1, build the patched U-Boot and load MLO/u-boot.img + +---------------------------------- +Boot from another medium like MMC +---------------------------------- + +U-Boot# mmc dev 0 +mmc0 is current device +U-Boot# fatload mmc 0 0x82000000 MLO +reading MLO +55872 bytes read in 8 ms (6.7 MiB/s) +U-Boot# fatload mmc 0 0x83000000 u-boot.img +reading u-boot.img +248600 bytes read in 19 ms (12.5 MiB/s) + +-------------------------------------------------- +Commands to erase/write u-boot/mlo to flash device +-------------------------------------------------- +U-Boot# sf probe 0 +SF: Detected S25FL256S_64K with page size 256 Bytes, erase size 64 KiB, total 32 MiB, mapped at 5c000000 +SF: Warning - Only lower 16MiB accessible, Full access #define CONFIG_SPI_FLASH_BAR +U-Boot# sf erase 0 0x10000 +SF: 65536 bytes @ 0x0 Erased: OK +U-Boot# sf erase 0x20000 0x10000 +SF: 65536 bytes @ 0x20000 Erased: OK +U-Boot# sf erase 0x30000 0x10000 +SF: 65536 bytes @ 0x30000 Erased: OK +U-Boot# sf erase 0x40000 0x10000 +SF: 65536 bytes @ 0x40000 Erased: OK +U-Boot# sf erase 0x50000 0x10000 +SF: 65536 bytes @ 0x50000 Erased: OK +U-Boot# sf erase 0x60000 0x10000 +SF: 65536 bytes @ 0x60000 Erased: OK +U-Boot# sf write 82000000 0 0x10000 +SF: 65536 bytes @ 0x0 Written: OK +U-Boot# sf write 83000000 0x20000 0x60000 +SF: 393216 bytes @ 0x20000 Written: OK + +For #2, set sysboot to QSPI-1 boot mode(SYSBOOT[5:0] = 100110) and power +on. ROM should find the GP header at offset 0 and load/execute SPL. SPL +then detects that ROM was in QSPI-1 mode (boot code 10) and attempts to +find a U-Boot image header at offset 0x20000 (set in the config file) +and proceeds to load that image using the U-Boot image payload offset/size +from the header. It will then start U-Boot. diff --git a/doc/SPI/README.ti_qspi_flash b/doc/SPI/README.ti_qspi_flash new file mode 100644 index 0000000..1b86d01 --- /dev/null +++ b/doc/SPI/README.ti_qspi_flash @@ -0,0 +1,47 @@ +QSPI U-boot support +------------------ + +Host processor is connected to serial flash device via qpsi +interface. QSPI is a kind of spi module that allows single, +dual and quad read access to external spi devices. The module +has a memory mapped interface which provide direct interface +for accessing data form external spi devices. + +The one QSPI in the device is primarily intended for fast booting +from Quad SPI flash devices. + +Usecase +------- + +MLO/u-boot.img will be flashed from SD/MMC to the flash device +using serial flash erase and write commands. Then, switch settings +will be changed to qspi boot. Then, the ROM code will read MLO +from the predefined location in the flash, where it was flashed and +execute it after storing it in SDRAM. Then, the MLO will read +u-boot.img from flash and execute it from SDRAM. + +SPI mode +------- +SPI mode uses mtd spi framework for transfer and reception of data. +Can be used in: +1. Normal mode: use single pin for transfers +2. Dual Mode: use two pins for transfers. +3. Quad mode: use four pin for transfer + +Memory mapped read mode +----------------------- +In this, SPI controller is configured using configuration port and then +controler is switched to memory mapped port for data read. + +Driver +------ +drivers/qspi/ti_qspi.c + - Newly created file which is responsible for configuring the + qspi controller and also for providing the low level api which + is responsible for transferring the datas from host controller + to flash device and vice versa. + +Testing +------- +A seperated file named README.dra_qspi_test has been created which gives all the +details about the commands required to test qspi at u-boot level.