[U-Boot] SPI flash on Altera socfpga

[Stefan Roese <sr@denx.de>]

On 20.04.2015 11:24, Pavel Machek wrote:
>> Which SPI flash are you talking about -- QSPI one or EPCS/EPCQ one ?
>>
>> I think Stefan got the QSPI one working. EPCQ is a bit trickier.
>
> Datasheet mentions QSPI_IO*/CLK/SS* pins, so I assume it is QSPI.

Yes, QSPI handles the SPI NOR flash chips on SoCFPGA.

>> On 20.04.2015 10:36, Pavel Machek wrote:
>>> I see that u-boot 2015.04 has SPI flash configured in the
>>> socfpga_cyclone5_socrates.dts. But as far as I know, socdk should have
>>> same SPI flash, right? Should similar dts part be enabled there, too?
>>
>> SPI NOR flash is working for me on SoCrates and another similar custom
>> SOCFPGA based board just fine.
>
> Thanks, that's useful to know.
>
>>> I tried to get the support to work on custom board, but was not
>>> successful so far. Does it work for you, or are still some parts
>>> missing?
>>
>> Not that I know of. What are the problems that you experience?
>
> For tests, I've used config similar to socrates, even through the
> board should be more similar to socdk:
>
> U-Boot 2015.04-rc4-00103-gef7e76c-dirty (Apr 20 2015 - 10:24:33)
>
> CPU:   Altera SoCFPGA Platform
>         Watchdog enabled
>         I2C:   ready
>         DRAM:  256 MiB
>         MMC:   SOCFPGA DWMMC: 0
>         Using default environment
>
> In:    serial
> Out:   serial
> Err:   serial
> Model: EBV SOCrates
> Net:   dwmac.ff702000
> Hit any key to stop autoboot:  0
> => sf probe
> Invalid chip select 0:0 (err=-19)
> SF: Failed to set up slave
> Failed to initialize SPI flash at 0:0
> =>

IIRC, then the aliases in the dts are very important for this:

  	aliases {
		spi0 = "/spi at ff705000";		/* QSPI */
		...

Did you add those to your dts as well?

> One thing that puzzles me:
>
> ./arch/arm/dts/socfpga_cyclone5_socrates.dts:	flash0: n25q00 at 0 {
> ./arch/arm/dts/socfpga_cyclone5_socrates.dts:		compatible = "n25q00";
>
> ..but I see no mention of that compatible string anywhere
> else. 2013-altera u-boot used ./drivers/mtd/spi/stmicro.c to handle
> it...

IIRC, the flash detection is done via autodetection by reading the 
parameters from the chip itself.

Thanks,
Stefan