Contains documentation and testing details for qspi flash interface.
Signed-off-by: Sourav Poddar sourav.poddar@ti.com --- doc/README.ti_qspi_dra_test | 38 ++++++++++++++++++++++++++++++++++ doc/README.ti_qspi_flash | 47 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 85 insertions(+), 0 deletions(-) create mode 100644 doc/README.ti_qspi_dra_test create mode 100644 doc/README.ti_qspi_flash
diff --git a/doc/README.ti_qspi_dra_test b/doc/README.ti_qspi_dra_test new file mode 100644 index 0000000..8910ff1 --- /dev/null +++ b/doc/README.ti_qspi_dra_test @@ -0,0 +1,38 @@ +------------------------------------------------- + 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 +---------------------------------- + +DRA752 EVM # mmc dev 0 +DRA752 EVM # fatload mmc 0 0x82000000 MLO +DRA752 EVM # fatload mmc 0 0x82000000 u-boot.img + +-------------------------------------------------- +Commands to erase/write u-boot/mlo to flash device +-------------------------------------------------- + +DRA752 EVM # sf probe 0 +[should detect the S25FL256S serial flash device] + +DRA752 EVM # sf erase 0 10000 +DRA752 EVM # sf erase 10000 10000 +DRA752 EVM # sf erase 20000 10000 +DRA752 EVM # sf erase 30000 10000 +DRA752 EVM # sf erase 40000 10000 +DRA752 EVM # sf erase 50000 10000 +DRA752 EVM # sf erase 60000 10000 + +DRA752 EVM # sf write 82000000 0 10000 +DRA752 EVM # sf write 83000000 20000 80000 + +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/README.ti_qspi_flash b/doc/README.ti_qspi_flash new file mode 100644 index 0000000..1b86d01 --- /dev/null +++ b/doc/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.