On Fri, Jan 20, 2017 at 10:06:03PM -0500, Chris Brandt wrote: > In the case of a single clock source, you don't need names. However, > if the controller has 2 clock sources, you need to name them correctly > so the driver can find the 2nd one. The 2nd clock is for the internal > card detect logic. > > Signed-off-by: Chris Brandt <chris.brandt@xxxxxxxxxxx> > --- > v4: > * just explain there might be 2 clocks, don't explain how > we will use them in the driver > v3: > * add more clarification about why there are sometimes 2 clocks > and what you should do with them. > * remove 'status = "disabled"' from example > v2: > * fix spelling and change wording > * changed clock name from "carddetect" to "cd" > --- > Documentation/devicetree/bindings/mmc/tmio_mmc.txt | 24 ++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt > index a1650ed..1464c16 100644 > --- a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt > +++ b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt > @@ -25,8 +25,32 @@ Required properties: > "renesas,sdhi-r8a7795" - SDHI IP on R8A7795 SoC > "renesas,sdhi-r8a7796" - SDHI IP on R8A7796 SoC > > +- clocks: Most controllers only have 1 clock source per channel. However, on > + some variations of this controller, the internal card detection This should be explicit as to which compatible strings have 2 clocks and which have 1 clock. > + logic that exists in this controller is sectioned off to be run by a > + separate second clock source to allow the main core clock to be turned > + off to save power. > + If 2 clocks are specified by the hardware, you must name them as > + "core" and "cd". > + If the controller only has 1 clock, naming is not required. > + > Optional properties: > - toshiba,mmc-wrprotect-disable: write-protect detection is unavailable > - pinctrl-names: should be "default", "state_uhs" > - pinctrl-0: should contain default/high speed pin ctrl > - pinctrl-1: should contain uhs mode pin ctrl > + > +Example showing 2 clocks: > + sdhi0: sd@e804e000 { mmc@... > + compatible = "renesas,sdhi-r7s72100"; > + reg = <0xe804e000 0x100>; > + interrupts = <GIC_SPI 270 IRQ_TYPE_LEVEL_HIGH > + GIC_SPI 271 IRQ_TYPE_LEVEL_HIGH > + GIC_SPI 272 IRQ_TYPE_LEVEL_HIGH>; > + > + clocks = <&mstp12_clks R7S72100_CLK_SDHI00>, > + <&mstp12_clks R7S72100_CLK_SDHI01>; > + clock-names = "core", "cd"; > + cap-sd-highspeed; > + cap-sdio-irq; > + }; > -- > 2.10.1 > > -- 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