On 1/5/25 12:39, Krzysztof Kozlowski wrote: > On 05/01/2025 10:51, Ivaylo Ivanov wrote: >> On 1/5/25 11:18, Krzysztof Kozlowski wrote: >>> On Sat, Jan 04, 2025 at 06:29:14PM +0200, Ivaylo Ivanov wrote: >>>> >>>> reg: >>>> maxItems: 1 >>>> @@ -64,7 +75,6 @@ properties: >>>> >>>> samsung,mode: >>>> $ref: /schemas/types.yaml#/definitions/uint32 >>>> - enum: [0, 1, 2, 3] >>> Widest constraints stay here, so minimum/maximum. >> Why? > Because that's the coding style and that's how you define the field, > considering you might miss a variant in multiple if:then: . > > >> If we are going to add new enum values specific for each USI version, >> isn't it better to selectively constrain them in the binding? > You are supposed to constrained them. > > Again: widest constrains always stay in top level property. This applies > to all bindings, all fields. Repeated multiple times, so here is > standard example: > > https://elixir.bootlin.com/linux/v6.11-rc6/source/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml#L127 Ah, I see now. Will get that fixed. > > >>>> description: >>>> Selects USI function (which serial protocol to use). Refer to >>>> <include/dt-bindings/soc/samsung,exynos-usi.h> for valid USI mode values. >>>> @@ -101,18 +111,42 @@ required: >>>> - samsung,sysreg >>>> - samsung,mode >>>> >>>> +allOf: >>>> + - if: >>>> + properties: >>>> + compatible: >>>> + contains: >>>> + enum: >>>> + - samsung,exynos850-usi >>>> + then: >>>> + properties: >>>> + reg: >>>> + maxItems: 1 >>>> + >>>> + samsung,mode: >>>> + enum: [0, 1, 2, 3] >>>> + >>>> + required: >>>> + - reg >>>> + >>>> + else: >>>> + properties: >>>> + reg: false >>>> + samsung,clkreq-on: false >>>> + >>>> + samsung,mode: >>>> + enum: [4, 5, 6, 7, 8, 9, 10] >>> Is it really true? Previously for example GS101 had values 0-3, now you >>> claim has values 4-10, so an ABI change without explanation. >> How is it unexplained? Citing the commit message: >> "Add constants for choosing USIv1 configuration mode in device tree. >> Those are further used in the USI driver to figure out which value to >> write into SW_CONF register." >> > I don't see reference here about GS101 and others. > >> USIv1 and v2 write different values to the SW_CONF register. For example: >> >> #define USI_V1_SW_CONF_UART 0x8 >> #define USI_V2_SW_CONF_UART BIT(0) >> >> .. >> [USI_V2_UART] = { .name = "uart", .val = USI_V2_SW_CONF_UART }, >> [USI_V1_UART] = { .name = "uart", .val = USI_V1_SW_CONF_UART }, >> .. >> >> Hence the decision to have separate constants for different USI versions, >> which in my opinion is cleaner than meshing the enums together and >> choosing what to use with IFs in the driver code. > This does not answer at all why GS101 receives now different values than > before. > > Explain why you are changing ABI. Oh I see what I've missed, it should be everything non-8895 having 0-3, not just the top-level compatible samsung,exynos850-usi. > >>>> + >>>> if: >>> Missing allOf: >>> >>>> properties: >>>> compatible: >>>> contains: >>>> enum: >>>> - samsung,exynos850-usi >>>> + - samsung,exynos8895-usi >>> Effect is not readable and not correct. You have two if:then:else. >>> Usually it is easier to just have separate if: for each group of >>> variants and define/constrain complete for such group within its if:. >>> >>>> >>>> then: >>>> properties: >>>> - reg: >>>> - maxItems: 1 >>>> - >>>> clocks: >>>> items: >>>> - description: Bus (APB) clock >>>> @@ -122,16 +156,13 @@ then: >>>> maxItems: 2 >>>> >>>> required: >>>> - - reg >>>> - clocks >>>> - clock-names >>>> >>>> else: >>>> properties: >>>> - reg: false >>>> clocks: false >>>> clock-names: false >>>> - samsung,clkreq-on: false >>>> >>>> additionalProperties: false >>>> >>>> diff --git a/include/dt-bindings/soc/samsung,exynos-usi.h b/include/dt-bindings/soc/samsung,exynos-usi.h >>>> index a01af169d..4c077c9a8 100644 >>>> --- a/include/dt-bindings/soc/samsung,exynos-usi.h >>>> +++ b/include/dt-bindings/soc/samsung,exynos-usi.h >>>> @@ -13,5 +13,12 @@ >>>> #define USI_V2_UART 1 >>>> #define USI_V2_SPI 2 >>>> #define USI_V2_I2C 3 >>>> +#define USI_V1_NONE 4 >>> Drop, it is already there. >>> >>>> +#define USI_V1_I2C0 5 >>>> +#define USI_V1_I2C1 6 >>>> +#define USI_V1_I2C0_1 7 >>>> +#define USI_V1_SPI 8 >>> Drop >>> >>>> +#define USI_V1_UART 9 >>> Drop >> How so? These bring different configuration values. Could you specify how >> exactly you want me to implement these in the driver? > Heh, so the binding was made poorly for the driver and driver was > developed in a matching way, so now this became an argument. Binding and > drivers are independent, so whatever argument was in the driver does not > matter really. > > What I don't understand is downstream for USIv1 and USIv2 has it correct > - proper string values without mentioning any version. So, surprisingly > proper downstream binding, really rare case, was converted to something > tied to current driver implementation. > > You have only one sort of property - the mode how you configure the USI > engine. The mode can be: I2C, SPI, I2C0, I2C1 for special cases with two > I2C etc. > > The mode is not "USI_V1_I2C" because it is redundant. USI V1 cannot be > USI V2. You cannot tell USI to be v1 or v2. It is either v1 or v2. Only > one of these, thus encoding this information in the binding is meaningless. > > I even mentioned this in original binding review: > "so please drop everywhere v2 (bindings, symbols, Kconfig, > functions) except the compatible." > Well, then I missed to check on that, so now this mess has to be fixed. Yeah I get it now. Alright, I'll look into what I can do to unmangle this mess. Thanks again! Best regards, Ivaylo > > Best regards, > Krzysztof
