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DRA726: EEPROM on SPI

Michel Catudal
Genius 3825 points
Part Number: DRA726

I am adapting u-boot to our boards that use the DRA726 processor. Our design uses an EEPROM on the SPI bus instead of I2C bus.

Much like the automotive EVM we have some configuration in EEPROM. I would like for u-boot to load a different device tree depending on the configuration found in EEPROM sort of the way it is done in the Beagleboard X15 or TI Industrial EVM. Do you have some example code I can work with. So far all I found was code for the I2C.

Michel

  • 0
    TI__Guru*** 125430 points
    We determine the board name by reading the EEPROM in board/ti/dra7xx/evm.c in the do_board_detect() function. At run-time we use the board name to specify the device tree file. See "findfdt" in include/configs/ti_omap5_common.h.
  • 0 in reply to Brad Griffis
    Genius 3825 points
    Brad,

    I know all that. The board_detect.c file reads the EEPROM which is on I2C port. Our design has the EEPROM on SPI2 with CS0. I created a directory for our board and want to modify that board_detect.c file so it access the EEPROM on SPI and not I2C.
    Memory size is another issue as I mentioned in another thread. We just have two 256MBx16 devices and the min in the EVM seems to be 2GB.

    For the ethernet in the DTS file, do I just remove the dual_emac lines and emac2 section or is there more to it than for single ethernet port use?

    Michel
  • 0 in reply to Michel Catudal
    TI__Guru*** 125430 points
    The McSPI driver would be the one located in u-boot at drivers/spi/omap3_spi.c. It does not appear to have DRA7xx support, so I expect you'll need to make some updates for base addresses. Or perhaps consider using an I2C EEPROM instead of a SPI flash.
  • 0 in reply to Brad Griffis
    Genius 3825 points
    Brad,

    It is not a SPI flash but a 25LC160 EEPROM. The design is done and the manufacturer in the process of creating the boards. There are multiple reasons to use this device, it is faster than the I2C device and we are already buying thousands of them for our misc customers. This is also the same device that we are using on our 4 inch LCD boards.
    The difference in price between the SPI and I2C device was not big enough to justify the use of the slower device.

    We have NOR Flash on QSPI.

    Michel