Messages in this thread | | | From | Andy Shevchenko <> | Date | Fri, 26 Apr 2019 21:26:50 +0300 | Subject | Re: [PATCH 2/2] gpio: sch: Add interrupt support |
| |
On Fri, Apr 26, 2019 at 8:52 PM Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote: > On Fri, Apr 26, 2019 at 08:44:36PM +0300, Andy Shevchenko wrote: > > On Fri, Apr 26, 2019 at 8:33 PM Manivannan Sadhasivam > > <manivannan.sadhasivam@linaro.org> wrote: > > > On Fri, Apr 26, 2019 at 08:20:19PM +0300, Andy Shevchenko wrote: > > > > On Fri, Apr 26, 2019 at 7:05 PM Jan Kiszka <jan.kiszka@siemens.com> wrote: > > > > > On 26.04.19 16:42, Enrico Weigelt, metux IT consult wrote: > > > > > > On 26.04.19 15:36, Jan Kiszka wrote: > > > > > > The problem here is opaque number. This has to be chip + *relative* pin number/ > > > > See this: > > > > https://stackoverflow.com/questions/55532410/how-do-linux-gpio-numbers-get-their-values/55579640#55579640 > > > > > > > > > > But for platform like 96Boards we don't need controller specific lookup, these > > > are all handled by the platform code [1] so that the users can use the standard > > > pinout number to access GPIOs. > > > > This is a complete mistake. > > > > There is *no* global GPIO numbers anymore in Linux. (I don't count > > very old legacy platforms) > > Read above, it applies to DT or whatever resource provider. > > > > I think you misunderstood what I said.
I think you misunderstood what I said. :)
> I referred the standard 96Boards > pinout and in the MRAA platform code, individual boards just map their > GPIO chip and line number based on that. I didn't mean the deprecated > global linux numbering.
It can be easily broken by shuffling DT, kernel cnfiguration and adding some GPIO expanders. Note, no C-code mangling is involved.
> > https://github.com/intel-iot-devkit/mraa/blob/master/src/arm/96boards.c#L109 > > And of couse as Jan mentioned, the chip number will change when some > other external GPIO controller got probed before but so far we haven't > got to it!
-- With Best Regards, Andy Shevchenko
| |