Thankyou for your comments.
On 10/06/13 14:52, Arnd Bergmann wrote:

On Monday 10 June 2013 10:27:05 Srinivas KANDAGATLA wrote:

quoted

+	soc {
+		pin-controller-sbc {
+			#address-cells	= <1>;
+			#size-cells	= <1>;
+			compatible	= "st,stih416-pinctrl", "simple-bus";

Why is this both its own device with a compatible string and a
"simple-bus" at the same time? Wouldn't it be simpler to just
scan the child device nodes from the "st,stih416-pinctrl"
driver instead of having a separate platform_driver for them?

Am happy to get rid of gpio platform_driver, But looking at the existing
pinctrl drivers like at91, they do it exactly like this.

Also having a gpio platform driver ties the resources to driver in a
neat way.

quoted

+			st,retime-in-delay	= <0 300 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250>;
+			st,retime-out-delay	= <0 300 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250>;
+			st,syscfg		= <&syscfg_sbc>;
+			st,syscfg-offsets	= <0 40 50 60 100>;
+			ranges;
+			PIO0: pinctrl at fe610000 {
+				#gpio-cells = <1>;
+				compatible = "st,stixxxx-gpio";
+				gpio-controller;
+				reg = <0xfe610000 0x100>;
+				st,bank-name  = "PIO0";
+				st,retime-pin-mask = <0xff>;
+			};
+			PIO1: pinctrl at fe611000 {
+				#gpio-cells	= <1>;
+				compatible	= "st,stixxxx-gpio";
+				gpio-controller;
+				reg = <0xfe611000 0x100>;
+				st,bank-name  = "PIO1";
+				st,retime-pin-mask = <0xff>;
+			};

What is in the ranges between these registers? It seems you have
256 bytes for each pinctrl node, with 4kb spacing. I wonder if
it would make sense to declare the entire range to belong to a single
pinctrl device. At least since all of the registers are in a single
range, you could add a property like

	ranges = <0 0xfe610000 0x10000>;

and use relative addresses in the sub-nodes.

OK, I will change to use ranges.

Please don't use identifiers with 'xxx' in them. Instead use numbers
of actual chips, ideally using the first one that this is compatible
with.

Ok, I will change st,stixxxx-gpio to st,stih415-gpio.

quoted

+		syscfg_sbc:syscfg at fe600000{
+			compatible	= "st,stih416-syscfg";
+			reg		= <0xfe600000 0x1000>;
+			syscfg-range	= <0 999>;
+			syscfg-name	= "SYSCFG_SBC";
+		};
+		syscfg_front:syscfg at fee10000{
+			compatible	= "st,stih416-syscfg";
+			reg		= <0xfee10000 0x1000>;
+			syscfg-range	= <1000 999>;
+			syscfg-name	= "SYSCFG_FRONT";
+		};

Did you mean to declare ranges excluding 1000 and 2000 here?
Normally I would expect inclusive ranges like syscfg-range=<0 1000>;

These numbers are from data sheet so I used it as it is.

What is the idea of the 'syscfg-name'? If the nodes are all different,

The idea of having syscfg-name is to lookup any sysconf bank(regmap)
from code which do not have reference to phandle from device trees.

I would expect them to have distinct "compatible" values and not
need them.

Yes, If we have distinct compatible we would not need them, but there
will be 5-10 compatibility list for each SOC.
It looks like its going to be much neater Am going to try this change
and see how it looks like.

	Arnd
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