On Wed, Nov 27, 2019 at 1:58 PM Romain Naour romain.naour@smile.fr wrote:
Hello,
I'm working on a modular socfpga based system with several optional boards. Each optional board contain a board ID that can be read through a SPI bus.
Since we want just read the board ID, we used manually the sspi command, something like:
=> sspi 1:1.0 8 0 42
But it seems that the sspi command can't be used in a uboot script. sspi seems only used to manually test spi drivers.
If we compare with i2c command, we have a i2c read to memory:
i2c read chip address[.0, .1, .2] length memaddress - read to memory
Why there is no such feature for spi ?
Probably because noone has needed it so far.
Is there an interest to evolve the sspi command to add a read to memory?
sspi <bus id>: <chip select>.<mode> <bit length> <data> <memaddress>
If you need it and provide a decent patch, I could probable get accepted...
By looking at existing code, it seems that hardware detection in uboot is handled by architecture/board specific code to set custom environment variable like "fpgatype" [1] or "unit_ident" "unit_serial" [2] (misc_init_r).
What do you recommend? Implement a custom misc_init_r() for hardware detection?
How is that related? How does reading to memory help you with knowing the hw type in scripts?
Anyway, I think board_late_init is a better fit than misc_init_r, which is rather meant to be a platform thing and vining can only use it because socfpga doesn't need it otherwise.
Regards, Simon
[1] https://gitlab.denx.de/u-boot/u-boot/blob/master/arch/arm/mach-socfpga/misc_... [2] https://gitlab.denx.de/u-boot/u-boot/blob/master/board/softing/vining_fpga/s...
Best regards, Romain _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot