Trying to bring the Firefly up on mainline(ish)

ac000

OK, so I added

&emmc {
        clock-frequency = <100000000>;
        clock-freq-min-max = <400000 150000000>;

        supports-highspeed;
        supports-emmc;
        bootpart-no-access;

        supports-DDR_MODE;
        caps2-mmc-hs200;

        ignore-pm-notify;
        keep-power-in-suspend;

        status = "okay";
};

To the device tree and now I get

Synopsys Designware Multimedia Card Interface Driver
dwmmc_rockchip ff0c0000.dwmmc: Using internal DMA controller.
dwmmc_rockchip ff0c0000.dwmmc: Version ID is 270a
dwmmc_rockchip ff0c0000.dwmmc: DW MMC controller at irq 64, 32 bit host data width, 256 deep fifo
platform ff0c0000.dwmmc: Driver dwmmc_rockchip requests probe deferral
dwmmc_rockchip ff0f0000.dwmmc: num-slots property not found, assuming 1 slot is available
dwmmc_rockchip ff0f0000.dwmmc: Using internal DMA controller.
dwmmc_rockchip ff0f0000.dwmmc: Version ID is 270a
dwmmc_rockchip ff0f0000.dwmmc: DW MMC controller at irq 67, 32 bit host data width, 256 deep fifo
dwmmc_rockchip ff0f0000.dwmmc: No vmmc regulator found
dwmmc_rockchip ff0f0000.dwmmc: No vqmmc regulator found

So it at least now seems to see (kind of) the eMMC, which is ff0f0000.dwmmc

(ff0c0000.dwmmc is the sdmmc, which I assume is the SD card slot?)

About those regulator not found messages. The sdmmc device tree entry has

vmmc-supply = <&vcc_sdmmc>;
vqmmc-supply = <&vccio_sd>;

Would the emmc entry need the same? Not sure it's safe to go blindly adding

these things without the possibility of causing damage?

Cheers,

Andrew

Astralix

@ac000:

You asked about NAND and I answered about NAND. But somewhere I told, that with eMMC you do not need any additional driver as the mainline dwmmc driver should work, if not, use the rkmmc. Then your partitions should be addressed as /dev/mmcblk0...

You can use rknand.ko as it can handle SD and MMC too, but it is not needed for eMMC as the usual drivers work fine.

If you need to sign and lock your systems images, you probably need to use RK Loader and rknand.ko but for open source you won't do that.

To avoid misunderstandings:

The word NAND is commonly used for raw NAND memory, having just blocks of FLASH. On the operating system side (Android / Linux /...)  additional software has to provide bad block management (BBT), error detection and correction (ECC) and wear-leveling (FTL).

eMMC is NAND behind a logic block that includes all of the above in hardware. So there is no additional software needed. You just write to a logical block device (LBA adressing) and the eMMC internal controller transfers LBA to physical memory blocks while keeping care of BBT, ECC and FTL.

Astralix

ac000

Thanks for the clarification.




Now I just need to know if it's safe to try adding




vmmc-supply = <&vcc_sdmmc>;
vqmmc-supply = <&vccio_sd>;




to the emmc device tree section? Or can getting these things

wrong severely knacker things up?




Cheers,

Andrew

Astralix

Andrew, I do not have any 3288 device yet, so I didn't check the device tree for them.?

Sorry, I will report back as soon, as I have something new for you.




Astralix

ac000

Maybe someone from Firefly could comment?




Essentially, what's the risk of causing hardware damage by using incorrect

entries in the device tree?




Cheers,

Andrew

busybee

Some geeks are working at it. The early work is at:



https://github.com/naobsd/linux/tree/na
... t-20141210