[U-Boot] Micron eMMC problem on sabre SD like card

[jean-francois simon]

Hi, Stefano, Fabio,

On Thu, Jun 6, 2013 at 6:39 AM, Fabio Estevam <festevam at gmail.com> wrote:
> On Thu, Jun 6, 2013 at 10:34 AM, Stefano Babic <sbabic at denx.de> wrote:
>> Could be the same as the issue reported by Fabio at
>> http://patchwork.ozlabs.org/patch/246928/ ?
>
> Yes, please apply this one and also:
> http://patchwork.ozlabs.org/patch/248877/
>
> With both patches applied SD functionality works well on mx6qsabresd.


Will do.
Also, I was looking around and came across this VSELECT bit in the
VEND_SPEC register (219_80C0 Vendor Specific Register
(uSDHC3_VEND_SPEC)   )

It is used to generate low voltage, like 1.8V (n bus SD3 here) which I
think is needed for DDR mode?
The Freescale code is using it here:

        /* Switch voltage to 1.8V if CMD11 succeeded */
        if (cmd->cmdidx == SD_CMD_SWITCH_UHS18V) {
                /* Set SD_VSELECT to switch to 1.8V */
                u32 reg;
                reg = readl(&regs->vendorspec);
                reg |= VENDORSPEC_VSELECT;
                writel(reg, &regs->vendorspec);

                /* Sleep for 5 ms - max time for card to switch to 1.8V */
                udelay(5000);

                /* Turn on SD clock */
                writel(reg | VENDORSPEC_FRC_SDCLK_ON, &regs->vendorspec);

                while (!(readl(&regs->prsstat) & PRSSTAT_DAT0))
                        ;

                /* restore SD clock status */
                writel(reg, &regs->vendorspec);
        }
"drivers/mmc/imx_esdhc.c" 714 lines --31%--

-jfs