diff mbox

[v2,2/3] mmc: sh_mobile_sdhi: explain clock bindings

Message ID 20170117195940.25092-3-chris.brandt@renesas.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chris Brandt Jan. 17, 2017, 7:59 p.m. UTC
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.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
---
 Documentation/devicetree/bindings/mmc/tmio_mmc.txt | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

Comments

Wolfram Sang Jan. 17, 2017, 8:33 p.m. UTC | #1
On Tue, Jan 17, 2017 at 02:59:39PM -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.
> 
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> ---
>  Documentation/devicetree/bindings/mmc/tmio_mmc.txt | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> index a1650ed..258b98c 100644
> --- a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> @@ -25,8 +25,29 @@ 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 cahnnel. However, some

channel.

> +	  have 2. If 2 clocks are specified, you must name them as "core" and

Maybe "However, some have a second clock dedicated to card detection."?

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Geert Uytterhoeven Jan. 18, 2017, 8:44 a.m. UTC | #2
Hi Chris,

On Tue, Jan 17, 2017 at 8:59 PM, Chris Brandt <chris.brandt@renesas.com> 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.
>
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> ---
>  Documentation/devicetree/bindings/mmc/tmio_mmc.txt | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> index a1650ed..258b98c 100644
> --- a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
> @@ -25,8 +25,29 @@ 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 cahnnel. However, some
> +         have 2. If 2 clocks are specified, you must name them as "core" and
> +         "carddetect". If the controller only has 1 clock, naming is not

Perhaps this clock should just be called "cd", as that's already an
established abbreviation for card detect in MMC DT bindings?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Chris Brandt Jan. 18, 2017, 2:58 p.m. UTC | #3
Hi Wolfram,

On Tuesday, January 17, 2017, Wolfram Sang wrote:
> > +- clocks: Most controllers only have 1 clock source per cahnnel.
> > +However, some
> 
> channel.
> 
> > +	  have 2. If 2 clocks are specified, you must name them as "core"
> > +and
> 
> Maybe "However, some have a second clock dedicated to card detection."?


Thank you for fixing my crappy spelling and grammar ;)



I'm glad C code uses 'if' and 'else' instead of 

	contemplate (x>y)
		X=1;
	alternatively
		y=1;


  ...then I'd be screwed!


Chris
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Chris Brandt Jan. 18, 2017, 3:11 p.m. UTC | #4
Hi Geert,

On Wednesday, January 18, 2017, Geert Uytterhoeven wrote:
> > +- clocks: Most controllers only have 1 clock source per cahnnel.

> However, some

> > +         have 2. If 2 clocks are specified, you must name them as

> "core" and

> > +         "carddetect". If the controller only has 1 clock, naming is

> > +not

> 

> Perhaps this clock should just be called "cd", as that's already an

> established abbreviation for card detect in MMC DT bindings?



OK, I'll change it.

Thanks,
Chris
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
index a1650ed..258b98c 100644
--- a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
@@ -25,8 +25,29 @@  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 cahnnel. However, some
+	  have 2. If 2 clocks are specified, you must name them as "core" and
+	  "carddetect". 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 {
+		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", "carddetect";
+		cap-sd-highspeed;
+		cap-sdio-irq;
+		status = "disabled";
+	};