Re: [PATCH 4/5] pwm: pwm-tipwmss: Update documentation to use empty range property

From: Rob Herring
Date: Thu Mar 17 2016 - 11:01:51 EST


On Mon, Mar 07, 2016 at 01:51:57PM -0600, Franklin S Cooper Jr wrote:
> Since the PWMSS and its subdevices (eCAP and ePWM) use the same address
> space then the range property should be empty. Update the documentation
> to show the correct usage.

Why does it matter? An empty ranges is generally not preferred.

>
> Signed-off-by: Franklin S Cooper Jr <fcooper@xxxxxx>
> ---
> Documentation/devicetree/bindings/pwm/pwm-tipwmss.txt | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-tipwmss.txt b/Documentation/devicetree/bindings/pwm/pwm-tipwmss.txt
> index f7eae77..672fa71 100644
> --- a/Documentation/devicetree/bindings/pwm/pwm-tipwmss.txt
> +++ b/Documentation/devicetree/bindings/pwm/pwm-tipwmss.txt
> @@ -7,11 +7,9 @@ Required properties:
> Should set to 1.
> - size-cells: specify number of u32 entries needed to specify child nodes size
> in reg property. Should set to 1.
> -- ranges: describes the address mapping of a memory-mapped bus. Should set to
> - physical address map of child's base address, physical address within
> - parent's address space and length of the address map. For am33xx,
> - 3 set of child register maps present, ECAP register space, EQEP
> - register space, EHRPWM register space.
> +- ranges: describes the address mapping of a memory-mapped bus. Its value
> + should be empty since no address translation is needed between the
> + parent and the child.
>
> Also child nodes should also populated under PWMSS DT node.
>
> @@ -23,9 +21,7 @@ pwmss0: pwmss@48300000 {
> #address-cells = <1>;
> #size-cells = <1>;
> status = "disabled";
> - ranges = <0x48300100 0x48300100 0x80 /* ECAP */
> - 0x48300180 0x48300180 0x80 /* EQEP */
> - 0x48300200 0x48300200 0x80>; /* EHRPWM */
> + ranges;
>
> /* child nodes go here */
> };
> --
> 2.7.0
>