Re: SDIO - High Speed - iMX6

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Hi Fabio,

I was able to work it.

Regards,

John

On Sat, Feb 14, 2015 at 10:48 AM, Fabio Estevam <festevam@xxxxxxxxx> wrote:
> Hi John,
>
> On Wed, Feb 11, 2015 at 10:24 PM, John Tobias <john.tobias.ph@xxxxxxxxx> wrote:
>> Hello All,
>>
>> We interface the WiLink8 (http://www.ti.com/lit/gpn/wl1807mod) in iMX6
>> custom board. The VIO is 1.8v and the kernel detect the chip in high
>> speed mode with a signal voltage of 3.3v.
>>
>> Is there a way to force the kernel to use a 1.8v signal voltage?.
>
> In drivers/mmc/core/sdio.c, function mmc_sdio_init_card() has:
>
>     /*
>      * If the host and card support UHS-I mode request the card
>      * to switch to 1.8V signaling level.  No 1.8v signalling if
>      * UHS mode is not enabled to maintain compatibility and some
>      * systems that claim 1.8v signalling in fact do not support
>      * it.
>      */
>     if (!powered_resume && (rocr & ocr & R4_18V_PRESENT)) {
>         err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
>                     ocr);
>
> Can you add a printk to check if mmc_set_signal_voltage() is getting called?
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