Re: [PATCH 1/2] ARM: socfpga: dts: Add support for SD/MMC

[Dinh Nguyen <dinguyen@altera.com>]

Hi Rob,

On Tue, 2013-06-11 at 20:47 -0500, Rob Herring wrote:
> On 06/11/2013 07:28 PM, dinguyen@altera.com wrote:
> > From: Dinh Nguyen <dinguyen@altera.com>
> > 
> > Add bindings for SD/MMC for SOCFPGA.
> > Add "syscon" to the "altr,sys-mgr" binding.
> 
> Not sure how I see syscon is related to SD? That is a pretty vague name
> as well.

This was 1 of Arnd's suggestion. I am making use of the mfd/syscon
driver for the platform's system manager IP block. This block has
registers that control other IP blocks in the SoC. The SD's CIU dividers
are in the system manager.

> 
> > Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
> > Reviewed-by: Pavel Machek <pavel@denx.de>
> > CC: Arnd Bergmann <arnd@arndb.de>
> > CC: Olof Johansson <olof@lixom.net>
> > Cc: Pavel Machek <pavel@denx.de>
> > Cc: Grant Likely <grant.likely@linaro.org>
> > Cc: Rob Herring <rob.herring@calxeda.com>
> > Cc: Chris Ball <cjb@laptop.org>
> > Cc: devicetree-discuss@lists.ozlabs.org
> > Cc: linux-mmc@vger.kernel.org
> > CC: <linux@arm.linux.org.uk>
> > 
> > v2:
> > - Add "syscon" to "altr,sys-mgr"
> > - Remove pwr-en field
> > ---
> >  .../devicetree/bindings/mmc/socfpga-dw-mshc.txt    |   60 ++++++++++++++++++++
> >  arch/arm/boot/dts/socfpga.dtsi                     |   13 ++++-
> >  arch/arm/boot/dts/socfpga_cyclone5.dts             |   13 +++++
> >  arch/arm/boot/dts/socfpga_vt.dts                   |   12 ++++
> >  4 files changed, 97 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> > new file mode 100644
> > index 0000000..9d7062c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> > @@ -0,0 +1,60 @@
> > +* Altera SOCFPGA specific extensions to the Synopsis Designware Mobile
> > +  Storage Host Controller
> > +
> > +Required Properties:
> > +
> > +* compatible: should be
> > +	- "altr,socfpga-dw-mshc": for controllers with Altera SOCFPGA
> > +	  specific extentions.
> 
> s/extentions/extensions/

Ok...

> 
> > +
> > +* altr,dw-mshc-ciu-div: Specifies the divider value for the card interface
> > +  unit (ciu) clock. The value should be (n-1). For Altera's SOCFPGA, the divider
> > +  value is fixed at 3, which mean parent_clock/4.
> > +
> > +* altr,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
> > +  in transmit mode and CIU clock phase shift value in receive mode for single
> > +  data rate mode operation. Refer notes below for the order of the cells and the
> > +  valid values.
> > +
> > +  Notes for the sdr-timing values:
> > +
> > +    The order of the cells should be
> > +      - First Cell: CIU clock phase shift value for RX mode, smplsel bits in
> > +	the system manager SDMMC control group.
> > +      - Second Cell: CIU clock phase shift value for TX mode, drvsel bits in
> > +	the system manager SDMMC control group.
> > +
> > +    Valid values for SDR CIU clock timing for SOCFPGA:
> > +      - valid value for tx phase shift and rx phase shift is 0 to 7.
> > +
> > +Required properties for a slot:
> > +
> > +* bus-width: Data width for card slot. 4-bit or 8-bit data.
> > +
> > +Example:
> > +
> > +  The MSHC controller node can be split into two portions, SoC specific and
> > +  board specific portions as listed below.
> > +
> > +	dwmmc0@ff704000 {
> > +		compatible = "altr,socfpga-dw-mshc";
> > +		reg = <0xff704000 0x1000>;
> > +		interrupts = <0 139 4>;
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +	};
> > +
> > +	dwmmc0@ff704000 {
> > +		num-slots = <1>;
> > +		supports-highspeed;
> > +		broken-cd;
> > +		fifo-depth = <0x400>;
> 
> Are these already documented. If so, can you add a reference to the
> binding doc.

yes, these are documented in:
Documentations/devicetree/bindings/mmc/synopsis-dw-mshc.txt

Thanks for the review.

Dinh
> 
> > +		altr,dw-mshc-ciu-div = <3>;
> > +      		altr,dw-mshc-sdr-timing = <0 3>;
> > +
> > +		slot@0 {
> > +			reg = <0>;
> > +			bus-width = <4>;
> > +		};
> > +	};
> > +
> > diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
> > index bee62a2..dbf7f22 100644
> > --- a/arch/arm/boot/dts/socfpga.dtsi
> > +++ b/arch/arm/boot/dts/socfpga.dtsi
> > @@ -468,6 +468,17 @@
> >  			cache-level = <2>;
> >  		};
> >  
> > +		mmc: dwmmc0@ff704000 {
> > +			compatible = "altr,socfpga-dw-mshc";
> > +			reg = <0xff704000 0x1000>;
> > +			interrupts = <0 139 4>;
> > +			fifo-depth = <0x400>;
> > +			#address-cells = <1>;
> > +			#size-cells = <0>;
> > +			clocks = <&l4_mp_clk>, <&sdmmc_clk>;
> > +			clock-names = "biu", "ciu";
> > +		};
> > +
> >  		/* Local timer */
> >  		timer@fffec600 {
> >  			compatible = "arm,cortex-a9-twd-timer";
> > @@ -521,7 +532,7 @@
> >  			};
> >  
> >  		sysmgr@ffd08000 {
> > -				compatible = "altr,sys-mgr";
> > +				compatible = "altr,sys-mgr", "syscon";
> >  				reg = <0xffd08000 0x4000>;
> >  			};
> >  	};
> > diff --git a/arch/arm/boot/dts/socfpga_cyclone5.dts b/arch/arm/boot/dts/socfpga_cyclone5.dts
> > index 973999d..1853cb1 100644
> > --- a/arch/arm/boot/dts/socfpga_cyclone5.dts
> > +++ b/arch/arm/boot/dts/socfpga_cyclone5.dts
> > @@ -54,6 +54,19 @@
> >  			status = "okay";
> >  		};
> >  
> > +		dwmmc0@ff704000 {
> > +			num-slots = <1>;
> > +			supports-highspeed;
> > +			broken-cd;
> > +			altr,dw-mshc-ciu-div = <3>;
> > +			altr,dw-mshc-sdr-timing = <0 3>;
> > +
> > +			slot@0 {
> > +				reg = <0>;
> > +				bus-width = <4>;
> > +			};
> > +		};
> > +
> >  		timer0@ffc08000 {
> >  			clock-frequency = <100000000>;
> >  		};
> > diff --git a/arch/arm/boot/dts/socfpga_vt.dts b/arch/arm/boot/dts/socfpga_vt.dts
> > index d1ec0ca..d93deb0 100644
> > --- a/arch/arm/boot/dts/socfpga_vt.dts
> > +++ b/arch/arm/boot/dts/socfpga_vt.dts
> > @@ -46,6 +46,18 @@
> >  			status = "okay";
> >  		};
> >  
> > +		dwmmc0@ff704000 {
> > +			num-slots = <1>;
> > +			supports-highspeed;
> > +			broken-cd;
> > +			altr,dw-mshc-ciu-div = <3>;
> > +
> > +			slot@0 {
> > +				reg = <0>;
> > +				bus-width = <4>;
> > +			};
> > +		};
> > +
> >  		timer0@ffc08000 {
> >  			clock-frequency = <7000000>;
> >  		};
> > 
> 
>