On 24/05/2023 05:30, Marek Vasut wrote: > On 5/18/23 16:26, Krzysztof Kozlowski wrote: >> On 17/05/2023 17:25, Marek Vasut wrote: >>> Add trivial bindings for driver which permits exposing syscon backed >>> register to userspace. This is useful e.g. to expose U-Boot boot >>> counter on various platforms where the boot counter is stored in >>> random volatile register, like STM32MP15xx TAMP_BKPxR register. >>> >>> Signed-off-by: Marek Vasut <marex@xxxxxxx> >>> --- >>> Cc: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx> >>> Cc: Conor Dooley <conor+dt@xxxxxxxxxx> >>> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx> >>> Cc: Marek Vasut <marex@xxxxxxx> >>> Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> >>> Cc: Rob Herring <robh+dt@xxxxxxxxxx> >>> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> >>> Cc: devicetree@xxxxxxxxxxxxxxx >>> Cc: kernel@xxxxxxxxxxxxxxxxxx >>> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx >>> --- >>> V2: Use generic syscon supernode >>> --- >>> .../bindings/nvmem/nvmem-syscon.yaml | 39 +++++++++++++++++++ >>> 1 file changed, 39 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/nvmem/nvmem-syscon.yaml >>> >>> diff --git a/Documentation/devicetree/bindings/nvmem/nvmem-syscon.yaml b/Documentation/devicetree/bindings/nvmem/nvmem-syscon.yaml >>> new file mode 100644 >>> index 0000000000000..7c1173a1a6218 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/nvmem/nvmem-syscon.yaml >>> @@ -0,0 +1,39 @@ >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/nvmem/nvmem-syscon.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: Generic syscon backed nvmem >>> + >>> +maintainers: >>> + - Marek Vasut <marex@xxxxxxx> >>> + >>> +allOf: >>> + - $ref: "nvmem.yaml#" >> >> Usual comment: drop quotes. We removed them everywhere, so you based >> your work on some old tree. >> >>> + >>> +properties: >>> + compatible: >>> + enum: >>> + - nvmem-syscon >>> + >>> + reg: >>> + maxItems: 1 >> >> Rob's questions are not solved. > > Can you reiterate this one ? I likely missed it. You did not solve the case of more than one register. This isn't an odd case. > >> The nvmem.yaml schema expects here to >> allow children. This should not be created per-register, but per entire >> block of registers. > > This thing works the other way around, I have a syscon register block > already, and I want to expose subset of it to userspace as read/write > accessible file to expose bootcounter available in that register (so I > can read it and reset it from user application). And this makes it too limited. I would expect one device exposing multiple blocks or registers, just like all nvmem providers are doing. Best regards, Krzysztof
