On 18/10/2024 14:26, Jerome Brunet wrote: > On Fri 18 Oct 2024 at 12:13, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > >> On 18/10/2024 11:20, Jerome Brunet wrote: >>> On Fri 18 Oct 2024 at 17:01, Xianwei Zhao <xianwei.zhao@xxxxxxxxxxx> wrote: >>> >>>> Hi Jerome, >>>> Thanks for your reply. >>>> >>>> On 2024/10/18 16:39, Jerome Brunet wrote: >>>>> [ EXTERNAL EMAIL ] >>>>> On Fri 18 Oct 2024 at 10:28, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: >>>>> >>>>>> On 18/10/2024 10:10, Xianwei Zhao via B4 Relay wrote: >>>>>>> From: Xianwei Zhao <xianwei.zhao@xxxxxxxxxxx> >>>>>>> >>>>>>> Add the new compatible name for Amlogic A4 pin controller, and add >>>>>>> a new dt-binding header file which document the detail pin names. >>>>> the change does not do what is described here. At least the description >>>>> needs updating. >>>>> >>>> >>>> Will do. >>>> >>>>> So if the pin definition is now in the driver, does it mean that pins have >>>>> to be referenced in DT directly using the made up numbers that are >>>>> created in pinctrl-amlogic-a4.c at the beginning of patch #2 ? >>>>> >>>> >>>> Yes. >>>> >>>>> If that's case, it does not look very easy a read. >>>>> >>>> >>>> It does happen. The pin definition does not fall under the category of >>>> binding. >>>> >>>> https://lore.kernel.org/all/106f4321-59e8-49b9-bad3-eeb57627c921@xxxxxxxxxxx/ >>> >>> So the expectation is that people will write something like: >>> >>> reset-gpios = <&gpio 42 GPIO_ACTIVE_LOW>; >>> >>> And others will go in the driver to see that is maps to GPIOX_10 ? the number >>> being completly made up, with no link to anything HW/Datasheet >>> whatsoever ? >>> >>> This is how things should be done now ? >> >> Why would you need to do this? Why it cannot be <&gpio 10 >> GPIO_ACTIVE_LOW>, assuming it is GPIO 10? >> >> Bindings have absolutely nothing to do with it. You have GPIO 10, not >> 42, right? > > That's what being proposed here, as far as I can see. > > GPIOX_10 (not GPIO 10) maps to 42. If this goes through, for DTs to be > valid in any OS, all need to share the same definition. That looks like > a binding to me. > > On these SOC, gpios in each controller are organized in bank with > different number of pins. So far, this was represented as single linear > array and that was not a problem since the mapping was part of the binding. > > Are you suggesting 2 params instead of one ? something like this maybe ? > > reset-gpios = <&gpio BANK_X 10 GPIO_ACTIVE_LOW>; No, I propose the same as you wrote: <&gpio 10 GPIO_ACTIVE_LOW> but I don't mind putting bank there. > > This means this A4 controller will be software incompatible with the > previous generation. It will need to handled differently eventhough the > HW is exactly the same. > > Note that some form of binding would still be required to define the > banks which are referenced by arbitrary letter in doc, not numbers. Usually banks are considered separate gpio controllers, so numbering always start from 0 because phandle encodes the bank. And this is exactly what Rob already asked in v1 review. Best regards, Krzysztof
