Thu, 14 Aug 2014 18:57:08 +0300 от Grygorii Strashko <grygorii.strashko@xxxxxx>:
...
> >>>> + dspgpio7: keystone_dsp_gpio@262025C {
> >>>> + compatible = "ti,keystone-mctrl-gpio";
> >>>> + gpio-controller;
> >>>> + #gpio-cells = <2>;
> >>>> + gpio,syscon-dev = <&devctrl 0x25c>;
> >>>> + };
> >>>
> >>> So, devctrl is a syscon device and this DTS introduce several
> >>> identical GPIO descriptions?
> >>>
> >>> On my opinion this should be placed in the gpio-syscon.c,
> >>> where you can add support for ti,keystone-dsp0{..7}-gpio.
> >>> Such change will avoid parts 2 and 3 of this patch.
> >>>
> >>> static const struct syscon_gpio_data ti_keystone_dsp0_gpio = {
> >>> .compatible = "ti,keystone-syscon",
> >>> .dat_bit_offset = 0x240 * 8,
> >>> ...
> >>> .set = etc...
> >>> };
> >>
> >> So, if I understand you right, you propose to add 8 additional compatible
> >> strings just to encode different register offsets. Is it?
> >> 1) add "ti,keystone-mctrl-gpio0"..."ti,keystone-mctrl-gpio7"
> >
> > Yes, but replace "mctrl" with "dsp" since mctrl is not applicable here.
> >
> >> 2) add 8 structures keystone_mctrl_gpio0..keystone_mctrl_gpio7 in gpio-syscon.c
> >> (which will have only different values of field - .dat_bit_offset = 0x2yy * 8,)
> >>
> >> 3) add 8 additional items in array syscon_gpio_ids
> >> {
> >> .compatible = "ti,keystone-mctrl-gpio0",
> >> .data = &keystone_mctrl_gpio0,
> >> }, ...
> >>
> >> I can do it if you strictly insist, BUT I don't like it :(
> >> - just imagine how your driver will look look like if 5 or 6 SoCs will re-use it ;)
> >> - as I mentioned in cover letter and commit messages even each SoC revision can have
> >> different Syscon implementation with different registers offsets and with different
> >> number of Syscon register ranges (for example for Keystone 2 we already have two
> >> Syscon devices defined in DT).
> >
> > The initial version of this driver contains addresses and offsets in, but this approach has
> > been criticized by DT maintainers.
>
> Could you provide link on this thread^, pls?
Here is a link to first version:
https://www.mail-archive.com/linux-gpio@xxxxxxxxxxxxxxx/msg01616.html
Unfortunately, I lost thread for DT-related stuffs.
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