Jaehoon, On Mon, Aug 25, 2014 at 1:50 AM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: > On 08/25/2014 05:13 PM, Ulf Hansson wrote: >> On 22 August 2014 20:27, Sonny Rao <sonnyrao@xxxxxxxxxxxx> wrote: >>> On Fri, Aug 22, 2014 at 8:31 AM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: >>>> On 22 August 2014 15:47, Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxx> wrote: >>>>> Exynos 5250 and 5420 based boards uses built-in CD# line for card >>>>> detection.But unfortunately CD# line is on the same voltage rails >>>>> as of I/O voltage rails. When we cut off vqmmc,the consequent card >>>>> detection will break in these boards. > > I didn't know that use CD# line for card detect. > And if CD# voltage rails and I/O voltage rail are same voltage, it doesn't make sense. > Which card is used with same voltages? (eMMC? SD? SDIO?) > > Well, I have checked Exynos5250 and 5420, but it looks like not same rails. I'm not sure I totally understood what you said. In my manual I have a table titled "Table 2-1 Exynos 5420 Pin List". Look in this table for XMMC2CDN and XMMC2DATA_0. Look to the right of the table and you'll see the power domain. For both it shows VDDQ_MMC2. If that doesn't mean that the two are in the same voltage domain then I don't know what does. Can you point to any examples where they have different voltage domains? I agree that what exynos does is not sensible, but that's what it is. >>>> I am not sure I follow here. >>>> >>>> Is the card detect mechanism handled internally by the dw_mmc controller? >>> >>> Yes > > What card detect mechanism? The dw_mmc controller has a way to read the card detect, right? That's internal to the controller. The alternative would be to use a generic GPIO for card detect. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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