On 25/05/2023 04:22, zhuyinbo wrote: > > > 在 2023/5/24 下午6:29, Conor Dooley 写道: >> On Wed, May 24, 2023 at 05:44:38PM +0800, zhuyinbo wrote: >>> >>> >>> 在 2023/5/24 下午4:56, Conor Dooley 写道: >>>> On Mon, May 22, 2023 at 03:10:29PM +0800, Yinbo Zhu wrote: >>>>> Add the Loongson platform spi binding with DT schema format using >>>>> json-schema. >>>>> >>>>> Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> >>>>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >>>>> --- >>>>> .../bindings/spi/loongson,ls2k-spi.yaml | 41 +++++++++++++++++++ >>>>> MAINTAINERS | 6 +++ >>>>> 2 files changed, 47 insertions(+) >>>>> create mode 100644 Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml b/Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml >>>>> new file mode 100644 >>>>> index 000000000000..d0be6e5378d7 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml >>>>> @@ -0,0 +1,41 @@ >>>>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: http://devicetree.org/schemas/spi/loongson,ls2k-spi.yaml# >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>> + >>>>> +title: Loongson SPI controller >>>>> + >>>>> +maintainers: >>>>> + - Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> >>>>> + >>>>> +allOf: >>>>> + - $ref: /schemas/spi/spi-controller.yaml# >>>>> + >>>>> +properties: >>>>> + compatible: >>>>> + enum: >>>>> + - loongson,ls2k-spi >>>> >>>> I am sorry to jump in here at such a late stage with a (potentially) >>>> trivial question. "ls2k" is the SoC family rather than a specific model >>>> as far as I understand. >>>> The answer is probably yes, but do all SoCs in the family have an >>>> identical version of the IP? >>> >>> >>> No, but the spi supported by this loongson spi driver are all the same >>> identical version, and other type or verion spi will be supported as >>> needed in the future. >> >> Does having a catch-all compatible make sense then when not all SoCs in >> the ls2k family will actually be able to use this driver? > > > Yes, it is make sense as it can reduce the workload of the community. > For the Loongson platform, the versions of spi peripherals are almost > the same, except for a few or individual SoCs. And we have also > discussed compatible internally, and we tend to define it this way. So you have chosen different path than what's clearly recommended by community, existing experience and documentation: https://elixir.bootlin.com/linux/v6.1-rc1/source/Documentation/devicetree/bindings/writing-bindings.rst#L42 Family names are not accepted as specific compatibles. Whenever they were accepted, it lead to problems. All the time. https://lore.kernel.org/all/20220822181701.GA89665-robh@xxxxxxxxxx/ https://lore.kernel.org/all/78651e07-6b3e-4243-8e1f-fcd1dfb3ffe1@xxxxxxxxxxxxxxxx/ https://lore.kernel.org/all/288f56ba9cfad46354203b7698babe91@xxxxxxxx/ https://lore.kernel.org/all/106e443a-e765-51fe-b556-e4e7e2aa771c@xxxxxxxxxx/ and many many more discussions. You should choose carefully, because we will keep NAK-ing adding properties to circumvent missing compatibles. > >> Or am I misunderstanding and all ls2k SoCs do work with this driver and >> you were talking about other, future products? > > Actually, in 2k500 has one special type spi was only one cs and their's > register definition was different from common type spi thus this driver > doesn't support but this driver can support another common type spi in > 2k500. for this special type spi I will add support as needed in the > future. Bindings are for hardware, not driver. What does your driver support or does not, matters less. Best regards, Krzysztof
