On 20/01/2022 08:30, Geert Uytterhoeven wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Hi Conor, > > On Mon, Jan 17, 2022 at 12:06 PM <conor.dooley@xxxxxxxxxxxxx> wrote: >> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> >> >> Add device tree bindings for the i2c controller on >> the Microchip PolarFire SoC. >> >> Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx> >> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > Thanks for your patch! > >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/i2c/microchip,mpfs-i2c.yaml >> @@ -0,0 +1,55 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$id: http://devicetree.org/schemas/i2c/microchip,mpfs-i2c.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: Microchip MPFS I2C Controller Device Tree Bindings >> + >> +maintainers: >> + - Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx> >> + >> +allOf: >> + - $ref: /schemas/i2c/i2c-controller.yaml# >> + >> +properties: >> + compatible: >> + enum: >> + - microchip,mpfs-i2c # Microchip PolarFire SoC compatible SoCs >> + - microchip,corei2c-rtl-v7 # Microchip Fabric based i2c IP core > > Wouldn't it be more logical to have: > > items: > - const: microchip,mpfs-i2c # Microchip PolarFire SoC compatible SoCs > - const: microchip,corei2c-rtl-v7 # Microchip Fabric based i2c IP core > > ? This would be fine for mpfs-i2c since corei2c is a "superset" - but how would that look for the fabric core? I don't think falling back from the fabric core onto the "hard" one makes sense. This would mean the following two entries: i2c2: i2c@44000000 { //fabric compatible = "microchip,corei2c-rtl-v7"; }; i2c1: i2c@2010b000 { //"hard" mpfs peripheral compatible = "microchip,mpfs-i2c", "microchip,corei2c-rtl-v7"; }; But this generates errors in dt_binding_check w/ your suggestion - so how about the following (similar to ti,omap4-i2c.yaml): compatible: oneOf: - items: - const: microchip,mpfs-i2c # Microchip PolarFire... - const: microchip,corei2c-rtl-v7 # Microchip Fabric... - const: microchip,corei2c-rtl-v7 # Microchip Fabric... Is there a prettier way than this duplication? > > If the IP core is reused, it can become: > > items: > - enum: > - microchip,mpfs-i2c # Microchip PolarFire SoC compatible SoCs > - microchip,<foo>-i2c # ... > - const: microchip,corei2c-rtl-v7 # Microchip Fabric based i2c IP core > > That way the driver can just match on the second (fallback) value, > and no further driver changes will be needed (until v8 or later). > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds >
