Hi Dharma, On Fri, Jan 19, 2024 at 08:41:04AM +0000, Dharma.B@xxxxxxxxxxxxx wrote: > Hi Sam, > On 19/01/24 1:00 am, Sam Ravnborg wrote: > > [You don't often get email from sam@xxxxxxxxxxxx. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > > Hi Dharma et al. > > > > On Thu, Jan 18, 2024 at 02:56:09PM +0530, Dharma Balasubiramani wrote: > >> Converted the text bindings to YAML and validated them individually using following commands > >> > >> $ make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/ > >> $ make dtbs_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/ > >> > >> changelogs are available in respective patches. > >> > >> Dharma Balasubiramani (3): > >> dt-bindings: display: convert Atmel's HLCDC to DT schema > >> dt-bindings: atmel,hlcdc: convert pwm bindings to json-schema > >> dt-bindings: mfd: atmel,hlcdc: Convert to DT schema format > > > > I know this is a bit late to ask - sorry in advance. > > > > The binding describes the single IP block as a multi functional device, > > but it is a single IP block that includes the display controller and a > > simple pwm that can be used for contrast or backlight. > yes. > > > > If we ignore the fact that the current drivers for hlcdc uses an mfd > > abstraction, is this then the optimal way to describe the HW? > > > > > > In one of my stale git tree I converted atmel lcdc to DT, and here > Are you referring the "bindings/display/atmel,lcdc.txt"? Correct. > > I used: > > > > + "#pwm-cells": > > + description: > > + This PWM chip use the default 3 cells bindings > > + defined in ../../pwm/pwm.yaml. > > + const: 3 > > + > > + clocks: > > + maxItems: 2 > > + > > + clock-names: > > + maxItems: 2 > > + items: > > + - const: lcdc_clk > > + - const: hclk > > > > This proved to be a simple way to describe the HW. > > > > To make the DT binding backward compatible you likely need to add a few > > compatible that otherwise would have been left out - but that should do > > the trick. > again you mean the compatibles from atmel,lcdc binding? If the new binding describes the full IP, as I suggest, then I assume you need to add the compatible "atmel,hlcdc-pwm" to be backward compatible. Otherwise users assuming the old binding will fail to find the pwm info. I am not sure how important this is - but at least then the device trees can be updated out of sync with the current users. I hope this explains what I tried to say, otherwise do not hesitate to get back to me. Sam
