socfpga: mmc problems

[dinguyen@altera.com (Dinh Nguyen)]

Hi Jack,

On Wed, 2013-07-03 at 16:01 +0100, Jack Mitchell wrote:
> Having received one of the new Arrow SoCkit boards at a recent training 
> day I set about seeing how far mainline was in successfully booting this 
> board.
> 
> As I wanted to boot from mmc, I first checked out linux-next [1] in 
> order to get the newly merged mmc driver, I then applied the device-tree 
> enablement series [2] on top before finally attempting to boot. I then 
> found that the standard socfpga_defconfig didn't enable the MMC drivers, 
> which I also did (should this be part of the socfpga_defconfig...?).

I was going to update this when I enable ethernet as well to avoid less
churn on the defconfig.

> 
> However, the boot hangs at:
> 
> Synopsys Designware Multimedia Card Interface Driver
> dwmmc_socfpga ff704000.dwmmc0: Using internal DMA controller.
> dwmmc_socfpga ff704000.dwmmc0: DW MMC controller at irq 171, 32 bit host 
> data width, 1024 deep fifo
> 
> To fix this I checked out the diff between the Altera vendor mmc driver 
> and the mainline driver and found that if I added this small change:
> 
> 
>    if (of_property_read_u32(dev->of_node, "pwr-en", &pwr_en)) {
>      dev_info(dev, "couldn't determine pwr-en, assuming pwr-en = 0\n");
>      pwr_en = 0;
>    }
> 
>    /* Set PWREN bit */
>    mci_writel(host, PWREN, pwr_en);

I tested this on my devkit, which was not made by Arrow, but is _almost_
the same. I'll try to see if I can get my hands on an Arrow board to
reproduce.

> 
> In the dw_mci_socfpga_priv_init function, the board would boot.
> 
> Synopsys Designware Multimedia Card Interface Driver
> dwmmc_socfpga ff704000.dwmmc0: couldn't determine pwr-en, assuming 
> pwr-en = 0
> dwmmc_socfpga ff704000.dwmmc0: Using internal DMA controller.
> dwmmc_socfpga ff704000.dwmmc0: DW MMC controller at irq 171, 32 bit host 
> data width, 1024 deep fifo
> mmc_host mmc0: Bus speed (slot 0) = 100000000Hz (slot req 400000Hz, 
> actual 400000HZ div = 125)
> dwmmc_socfpga ff704000.dwmmc0: 1 slots initialized
> dwmmc_socfpga ff704000.dwmmc0: Version ID is 240a
> .....
> .....
> .....
> 
> 
> Has this been overlooked, or are there some other changes elsewhere that 
> I haven't yet come across which addresses this?

I'm not aware of any other changes.

Dinh
> 
> Cheers,
> 
> [1] fa1383200d289afdff2f5678eb89483daa537465
> [2] http://comments.gmane.org/gmane.linux.ports.arm.kernel/243529
>