Messages in this thread | | | Date | Wed, 11 Sep 2019 11:11:01 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH] pinctrl: at91-pio4: implement .get_multiple and .set_multiple |
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On 11/09/2019 01:27:10+0100, Linus Walleij wrote: > On Thu, Sep 5, 2019 at 3:13 PM Alexandre Belloni > <alexandre.belloni@bootlin.com> wrote: > > > > Implement .get_multiple and .set_multiple to allow reading or setting > > multiple pins simultaneously. Pins in the same bank will all be switched at > > the same time, improving synchronization and performances. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > Good initiative! > > > + for (bank = 0; bank < atmel_pioctrl->nbanks; bank++) {> + unsigned int word = bank; > > + unsigned int offset = 0; > > + unsigned int reg; > > + > > +#if ATMEL_PIO_NPINS_PER_BANK != BITS_PER_LONG > > Should it not be > rather than != ? >
Realistically, the only case that could happen would be ATMEL_PIO_NPINS_PER_BANK == 32 and BITS_PER_LONG ==64. so I would go for ATMEL_PIO_NPINS_PER_BANK < BITS_PER_LONG
> > + word = BIT_WORD(bank * ATMEL_PIO_NPINS_PER_BANK); > > + offset = bank * ATMEL_PIO_NPINS_PER_BANK % BITS_PER_LONG; > > +#endif > > This doesn't look good for multiplatform kernels. >
I don't think we have multiplatform kernels that run both in 32 and 64 bits. I don't believe ATMEL_PIO_NPINS_PER_BANK will ever change, it has been 32 on all the atmel SoCs since 2001.
> We need to get rid of any compiletime constants like this. > > Not your fault I suppose it is already there, but this really need > to be fixed. Any ideas? >
I can go for a variable instead of a constant but the fact is that there is currently no 64bit SoC with that IP. I added the compile time check just in case a 64 bit SoC appears with that IP one day.
-- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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