[PATCH 1/5] soc: renesas: Add symbols for R-Car Gen3 register offsets

[Geert Uytterhoeven]

Hi Simon,

On Thu, Feb 15, 2018 at 4:02 PM, Simon Horman <horms at verge.net.au> wrote:
> On Wed, Feb 14, 2018 at 11:25:19AM +0100, Geert Uytterhoeven wrote:
>> On Mon, Feb 12, 2018 at 4:44 PM, Simon Horman
>> <horms+renesas at verge.net.au> wrote:
>> > Add symbols for Gen3 register offsets.
>> > These may be used to improve readability of users of these offsets.
>> >
>> > This does not introduce any functional change.
>> >
>> > Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
>>
>> Thanks for your patch!
>>
>> > --- a/drivers/soc/renesas/rcar-sysc.h
>> > +++ b/drivers/soc/renesas/rcar-sysc.h
>> > @@ -24,6 +24,25 @@
>> >  #define PD_CPU_NOCR    PD_CPU | PD_NO_CR /* CPU area lacks CR (R-Car Gen2/3) */
>> >  #define PD_ALWAYS_ON   PD_NO_CR          /* Always-on area */
>> >
>> > +/*
>> > + * R-Car Gen3 register offsets
>> > + */
>> > +
>> > +#define RCAR_GEN3_SYSCSR  0
>>
>> Please drop this. The "always-on" domains use 0 to indicate "no register
>> block", not as a reference to the SYSCSR register.
>
> Ok, understood.
>
> Could I tempt you with RCAR_SYSC_ALWAYS_ON ?

IMHO that obfuscates what's going on, while 0 is a clear indicator.

>> > +#define RCAR_GEN3_PWRSR0  0x80
>> > +#define RCAR_GEN3_PWRSR2  0x100
>> > +#define RCAR_GEN3_PWRSR3  0x140
>> > +#define RCAR_GEN3_PWRSR4  0x180
>> > +#define RCAR_GEN3_PWRSR5  0x1c0
>> > +#define RCAR_GEN3_PWRSR6  0x200
>> > +#define RCAR_GEN3_PWRSR7  0x240
>> > +#define RCAR_GEN3_PWRSR8  0x340
>> > +#define RCAR_GEN3_PWRSR9  0x380
>> > +#define RCAR_GEN3_PWRSR10 0x3c0
>> > +#define RCAR_GEN3_PWRSR11 0x400
>> > +#define RCAR_GEN3_PWRSR12 0x2c0
>> > +#define RCAR_GEN3_PWRSR13 0x300
>> > +#define RCAR_GEN3_PWRSR14 0x280
>>
>> What about
>>
>>     #define RCAR_GEN3_PWRSR(n) (0x80 + (n) * 0x40)
>>
>> instead?
>> Bummer, they have a hole between 0x240 and 0x340, which they filled later :-(
>> So I don't know how stable the PWRSRx indices are...
>
> Ok, would you rather use the approach I provided or wait?

Your approach is fine, due to the non-contiguous numbering.
Although I still have mixed feelings, as I usually look at the actual
base offsets,
not register abbreviations, when adding/reviewing support for new SoCs.
I may be biased, though.

Jacopo/Sergei: You were the last persons adding a new SYSC driver.
Do you have any opinion?

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds