Re: [PATCH v4 3/3] powerpc: doc/dts-bindings: update doc of FSL I2C bindings

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Thu, Jan 28, 2010 at 6:25 AM, Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org> wrote:
> From: Wolfgang Grandegger <wg-ynQEQJNshbs@public.gmane.org>
>
> This patch adds the MPC5121 to the list of supported devices,
> enhances the doc of the "clock-frequency" property and removes
> the obsolete "cell-index" property from the example nodes.
> Furthermore and example for the MPC5121 has been added.
>
> Signed-off-by: Wolfgang Grandegger <wg-ynQEQJNshbs@public.gmane.org>

Thanks Wolfgang.  Comments below.

> ---
>  Documentation/powerpc/dts-bindings/fsl/i2c.txt |   30 +++++++++++++++++++----
>  1 files changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/powerpc/dts-bindings/fsl/i2c.txt b/Documentation/powerpc/dts-bindings/fsl/i2c.txt
> index b6d2e21..2f62dae 100644
> --- a/Documentation/powerpc/dts-bindings/fsl/i2c.txt
> +++ b/Documentation/powerpc/dts-bindings/fsl/i2c.txt
> @@ -9,8 +9,9 @@ Recommended properties :
>
>  - compatible : compatibility list with 2 entries, the first should
>    be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor,
> -   e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one
> -   should be "fsl-i2c".
> +   e.g. mpc8313, mpc8543, mpc8544, mpc5121, mpc5200 or mpc5200b. The
> +   second one should be "fsl-i2c". For the mpc5121, an additional node
> +   "fsl,mpc5121-i2c-ctrl" is required as shown in the example below.

While you're editing this line; drop the requirement for the second
value to be 'fsl-i2c'.  We don't use it anymore, and only preserve it
for backwards compatibility with old trees.

>  - interrupts : <a b> where a is the interrupt number and b is a
>    field that represents an encoding of the sense and level
>    information for the interrupt.  This should be encoded based on
> @@ -20,29 +21,46 @@ Recommended properties :
>    services interrupts for this device.
>  - fsl,preserve-clocking : boolean; if defined, the clock settings
>    from the bootloader are preserved (not touched).
> - - clock-frequency : desired I2C bus clock frequency in Hz.
> + - clock-frequency : desired I2C bus clock frequency in Hz.  If this
> +   property and "fsl,preserve-clocking" is not defined, a safe fixed
> +   clock divider value is used (resulting in a small clock frequency).

Nah, leave this as is.  Don't make it sound like omitting both
properties is a valid option.  The driver may (and should!) handle the
situation gracefully, but that fact does not need to be documented.

>
>  Examples :
>
> +       /* MPC5121 based board */
> +       i2c@1740 {
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +               compatible = "fsl,mpc5121-i2c", "fsl-i2c";
> +               reg = <0x1740 0x20>;
> +               interrupts = <11 0x8>;
> +               interrupt-parent = <&ipic>;
> +               clock-frequency = <100000>;
> +       };
> +
> +       i2ccontrol@1760 {
> +               compatible = "fsl,mpc5121-i2c-ctrl";
> +               reg = <0x1760 0x8>;
> +       };
> +
> +       /* MPC5200B based board */
>        i2c@3d00 {
>                #address-cells = <1>;
>                #size-cells = <0>;
>                compatible = "fsl,mpc5200b-i2c","fsl,mpc5200-i2c","fsl-i2c";
> -               cell-index = <0>;
>                reg = <0x3d00 0x40>;
>                interrupts = <2 15 0>;
>                interrupt-parent = <&mpc5200_pic>;
>                fsl,preserve-clocking;
>        };
>
> +       /* MPC8544 base board */
>        i2c@3100 {
>                #address-cells = <1>;
>                #size-cells = <0>;
> -               cell-index = <1>;
>                compatible = "fsl,mpc8544-i2c", "fsl-i2c";
>                reg = <0x3100 0x100>;
>                interrupts = <43 2>;
>                interrupt-parent = <&mpic>;
>                clock-frequency = <400000>;
>        };
> -
> --
> 1.6.2.5
>
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-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.