Leela
On Fri, Jun 14, 2013 at 5:21 AM, Leela Krishna Amudala
<l.krishna@xxxxxxxxxxx> wrote:
> Here the GPIO pins added for sd0_bus1, sd0_bus4 and sd0_bus8 are correct
> Please look at the below example dwmmc node configured for 8bit bus width
>
> dwmmc0@12200000 {
> /*...*/
> pinctrl-names = "default";
> pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus4 &sd0_bus8>;
>
> slot@0 {
> reg = <0>;
> bus-width = <8>;
> };
> };
>
> In the above node we are specifying "&sd0_bus4 &sd0_bus8" in pinctrl-0
> Pinctrl driver will configure the respective gpio pins given in
> sd0_bus4 and sd0_bus8 nodes.
> (which are "gpc0-3", "gpc0-4", "gpc0-5", "gpc0-6", "gpc3-0", "gpc3-1",
> "gpc3-2", "gpc3-3")
>
> But if we make gpio entries for sd0_bus1, sd0_bus4 and sd0_bus8 like below
>
> sd0_bus1: sd0-bus-width1 {
> samsung,pins = "gpc0-3";
> /*...*/
> };
>
> sd0_bus4: sd0-bus-width4 {
> samsung,pins = "gpc0-4", "gpc0-5", "gpc0-6";
> /*...*/
> };
>
> sd0_bus8: sd0-bus-width8 {
> samsung,pins = "gpc3-0", "gpc3-1", "gpc3-2", "gpc3-3";
> /*...*/
> };
>
> we have to make entries like below for dwmmc node to configure 8bit bus width.
> pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus1 &sd0_bus4 &sd0_bus8>;
>
> or if we choose like below
>
> sd0_bus1: sd0-bus-width1 {
> samsung,pins = "gpc0-3";
> /*...*/
> };
>
> sd0_bus4: sd0-bus-width4 {
> samsung,pins = "gpc0-3", "gpc0-4", "gpc0-5", "gpc0-6";
> /*...*/
> };
>
> sd0_bus8: sd0-bus-width8 {
> samsung,pins = "gpc0-3", "gpc0-4", "gpc0-5",
> "gpc0-6", "gpc3-0", "gpc3-1", "gpc3-2", "gpc3-3";
> /*...*/
> };
>
> Then specifying pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus8>; is enough
>
> Because all the other boards have the similar kind of nodes specified
> in their DT files, I followed the same convention.
Right. I think what we're saying here is that all the other boards
are wrong and ought to be fixed in a separate patch. ...following
existing convention is often a good thing to do, but in this case
we're asking to break convention and do the correct thing.
I think Tomasz expressed a desire to use the syntax:
pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus1 &sd0_bus4 &sd0_bus8>;
-Doug
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