Hi Frank,
> On Dec 28, 2016, at 09:20 , frowand.list@xxxxxxxxx wrote:
>
> From: Frank Rowand <frank.rowand@xxxxxxxxxxx>
>
> In response to "Subject: Re: [PATCH v11 5/7] overlay: Documentation for the
> overlay sugar syntax" I suggested a tool to convert the old style of dts
> overlay files to use the new syntactic sugar [1]:
>
>>>> I can imagine some reasons to support the fully written out version,
>>>> but can we document what those reasons are?
>>>
>>> I believe the main one is the dts files in this format out in the
>>> field. Mind you, I guess we're already requiring them to tweak how
>>> they declare the /plugin/ option.
>>
>> It might be easy to write a program that transforms the expanded
>> format to the simple format. I'll try to make some time to see
>> how difficult it is. The transformation is relatively easy to
>> do manually, but I don't know how many dts files would need to
>> be converted.
>
> My goal is to minimize legacy issues of dts files that expose the
> internal implementation of overlays, such as the fragment and
> __overlay__ nodes. Pantelis has submitted the dtc patches to add
> the necessary syntactic sugar, and these appear to be moving toward
> acceptance.
>
> I have created a perl script to create a new style dts overlay file
> from an old style dts overlay file. I have also created a shell
> script to provide some error checking and to validate that the
> new dts file compiles to the same result as the old dts file.
>
> I treat the issue as a simplistic text processing exercise instead
> of using a more complex approach with the hope that this is
> sufficient to process the bulk of the existing in the wild overlay
> dts files.
>
> I do not think it is worth cluttering the dtc git repo with these
> tools, but have no objection to them being hosted there if David
> prefers. I can host them on github, elinux.org, or anywhere else
> that makes sense for a (hopefully) short lived tool.
>
> Patches 3, 4, and 5 are sample old style dts overlay files and
> are not intended to be committed.
>
> Following are several examples of use. One example that converts
> properly and two that show how convsersion a malformed old style
> dts is reported.
>
> ----- example 1
>
> $ export PATH="$PATH:/home/frowand/nobackup/src/github_pantelis/dtc/"
> $ ./overlay_convert_old_to_new a.dts b.dts
>
> $ cat a.dts
> /dts-v1/;
> /plugin/;
>
> / {
> fragment@0 {
> target = <&am3353x_pinmux>;
>
> __overlay__ {
>
> i2c1_pins: pinmux_i2c1_pins {
> pinctrl-single,pins = <
> 0x158 0x72
> 0x15c 0x72
> >;
> };
> };
> };
>
> fragment@1 {
> target = <&i2c1>;
>
> __overlay__ {
> #address-cells = <1>;
> #size-cells = <0>;
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <400000>;
> status = "okay";
>
> at24@50 {
> compatible = "at,24c256";
> pagesize = <64>;
> reg = <0x50>;
> };
> };
> };
> };
> $ cat b.dts
> /dts-v1/;
> /plugin/;
>
> &am3353x_pinmux {
>
> i2c1_pins: pinmux_i2c1_pins {
> pinctrl-single,pins = <
> 0x158 0x72
> 0x15c 0x72
> >;
> };
> };
>
> &i2c1 {
> #address-cells = <1>;
> #size-cells = <0>;
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <400000>;
> status = "okay";
>
> at24@50 {
> compatible = "at,24c256";
> pagesize = <64>;
> reg = <0x50>;
> };
> };
> $ diff -u a.dts b.dts
> --- a.dts 2016-12-27 15:51:36.433101164 -0800
> +++ b.dts 2016-12-27 22:01:28.541530464 -0800
> @@ -1,11 +1,7 @@
> /dts-v1/;
> /plugin/;
>
> -/ {
> - fragment@0 {
> - target = <&am3353x_pinmux>;
> -
> - __overlay__ {
> + &am3353x_pinmux {
>
> i2c1_pins: pinmux_i2c1_pins {
> pinctrl-single,pins = <
> @@ -14,12 +10,8 @@
> >;
> };
> };
> - };
> -
> - fragment@1 {
> - target = <&i2c1>;
>
> - __overlay__ {
> + &i2c1 {
> #address-cells = <1>;
> #size-cells = <0>;
> pinctrl-names = "default";
> @@ -33,5 +25,3 @@
> reg = <0x50>;
> };
> };
> - };
> -};
>
>
> ----- example 2
>
> $ export PATH="$PATH:/home/frowand/nobackup/src/github_pantelis/dtc/"
> $ ./overlay_convert_old_to_new bad_a_1.dts bad_b_1.dts
> No 'target' property in node fragment@0
>
> ERROR: unable to convert bad_a_1.dts
>
> $ cat bad_a_1.dts
> /dts-v1/;
> /plugin/;
>
> / {
> fragment@0 {
>
> __overlay__ {
>
> i2c1_pins: pinmux_i2c1_pins {
> pinctrl-single,pins = <
> 0x158 0x72
> 0x15c 0x72
> >;
> };
> };
> };
>
> fragment@1 {
> target = <&i2c1>;
>
> __overlay__ {
> #address-cells = <1>;
> #size-cells = <0>;
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <400000>;
> status = "okay";
>
> at24@50 {
> compatible = "at,24c256";
> pagesize = <64>;
> reg = <0x50>;
> };
> };
> };
> };
>
>
> ----- example 3
>
> $ export PATH="$PATH:/home/frowand/nobackup/src/github_pantelis/dtc/"
> $ ./overlay_convert_old_to_new bad_a_2.dts bad_b_2.dts
> No 'target' property in node fragment@1
>
> ERROR: unable to convert bad_a_2.dts
>
> $ cat bad_a_2.dts
> /dts-v1/;
> /plugin/;
>
> / {
> fragment@0 {
> target = <&am3353x_pinmux>;
>
> __overlay__ {
>
> i2c1_pins: pinmux_i2c1_pins {
> pinctrl-single,pins = <
> 0x158 0x72
> 0x15c 0x72
> >;
> };
> };
> };
>
> fragment@1 {
>
> __overlay__ {
> #address-cells = <1>;
> #size-cells = <0>;
> pinctrl-names = "default";
> pinctrl-0 = <&i2c1_pins>;
> clock-frequency = <400000>;
> status = "okay";
>
> at24@50 {
> compatible = "at,24c256";
> pagesize = <64>;
> reg = <0x50>;
> };
> };
> };
> };
>
>
>
> [1] http://www.spinics.net/lists/devicetree/msg152891.html
>
Very interesting and helpful.
Thanks for the good work. I would support converting all overlays in the wild
to the new format to get going on the connector problem.
> Frank Rowand (5):
> perl script to convert dts from old overlay style to new overlay style
> shell script to make overlay_convert easier to use
> a.dts: example of an old style dts file to be converted
> bad_a_1.dts: example of an old style dts file unable to be converted
> bad_a_2.dts: example of an old style dts file to be converted
>
Regards
— Pantelis
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