Thread (11 messages) 11 messages, 2 authors, 2013-08-12

[PATCHv2] ARM: socfpga: dts: Add support for SD/MMC

From: Stephen Warren <hidden>
Date: 2013-08-08 20:14:18
Also in: linux-mmc

On 08/05/2013 02:43 PM, dinguyen at altera.com wrote:
From: Dinh Nguyen <redacted>

Add bindings for SD/MMC for SOCFPGA.
Add "syscon" to the "altr,sys-mgr" binding.
quoted hunk ↗ jump to hunk
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..dc14922
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
@@ -0,0 +1,48 @@
+* 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 extensions.
+
+* 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 means parent_clock/4.
This feels like something that should be represented using the common
clock API; a driver should query the rate of its input clock, and then
calculate the MMC block's internal divider based on that (perhaps also
call clk_set_rate() on the input clock?).
+Example:
+	dwmmc0 at ff704000 {
+		compatible = "altr,socfpga-dw-mshc", "snps,dw-mshc";
+		reg = <0xff704000 0x1000>;
+		interrupts = <0 139 4>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		num-slots = <1>;
+		supports-highspeed;
+		fifo-depth = <0x400>;
Those properties aren't defined in this document anywhere. I guess this
binding is meant to "inherit" from that described in
"synopsis-dw-mshc.txt"? If so, that should be stated explicitly.

A similar comment applies to the clocks properties in the *.dtsi changes.
+		altr,dw-mshc-ciu-div = <3>;
+      		altr,dw-mshc-sdr-timing = <0 3>;
Indentation issue.
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