On Wed, Jun 08, 2016 at 01:52:20PM -0700, Doug Anderson wrote: > Rob, > > On Wed, Jun 8, 2016 at 1:19 PM, Rob Herring <robh@xxxxxxxxxx> wrote: > > On Tue, Jun 07, 2016 at 03:44:39PM -0700, Douglas Anderson wrote: > >> Some SD/eMMC PHYs (like the PHY from Arasan that is designed to work > >> with arasan,sdhci-5.1) need to know the card clock in order to function > >> properly. Let's expose this clock using a standard device tree > >> mechanism so that the PHY can get access to and query the card clock. > > > > Need to know the clock freq or need the clock? The former doesn't need > > to be in DT. > > The PHY needs to know the card clock frequency. This clock clock > frequency is known nowhere else in the system except the SDHCI driver > since the SDHCI component takes its input clock and applies some > dividers to get the card clock. In silicon, the SDHCI component and > the PHY are separate and there is a physical clock signal going from > the SDHCI component to the PHY component, so modeling this as a clock > in in the device tree seems sane, doesn't it? Yes, please just re-word it to make it clear there is a connection. With that, Acked-by: Rob Herring <robh@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
