Hi Tomi,
On Tue, 28 Oct 2025 at 18:15, Tomi Valkeinen
<[email protected]> wrote:
> On 05/10/2025 06:02, Marek Vasut wrote:
> > --- a/drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi_regs.h
> > +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi_regs.h
> > @@ -246,14 +246,14 @@
> >
> > #define VCLKSET 0x100c
> > #define VCLKSET_CKEN (1 << 16)
> > -#define VCLKSET_COLOR_RGB (0 << 8)
> > -#define VCLKSET_COLOR_YCC (1 << 8)
> > +#define VCLKSET_COLOR_YCC (1 << 8) /* 0:RGB 1:YCbCr */
> > #define VCLKSET_DIV_V3U(x) (((x) & 0x3) << 4)
> > #define VCLKSET_DIV_V4H(x) (((x) & 0x7) << 4)
> > -#define VCLKSET_BPP_16 (0 << 2)
> > -#define VCLKSET_BPP_18 (1 << 2)
> > -#define VCLKSET_BPP_18L (2 << 2)
> > -#define VCLKSET_BPP_24 (3 << 2)
> > +#define VCLKSET_BPP_MASK (3 << 2)
> > +#define VCLKSET_BPP_16 FIELD_PREP(VCLKSET_BPP_MASK,
> > 0)
> > +#define VCLKSET_BPP_18 FIELD_PREP(VCLKSET_BPP_MASK,
> > 1)
> > +#define VCLKSET_BPP_18L FIELD_PREP(VCLKSET_BPP_MASK,
> > 2)
> > +#define VCLKSET_BPP_24 FIELD_PREP(VCLKSET_BPP_MASK,
> > 3)
> > #define VCLKSET_LANE(x) (((x) & 0x3) << 0)
> It probably doesn't matter, but just wanted to mention: here FIELD_PREP
> is used with, e.g., (3 << 2). GENMASK returns an unsigned value, whereas
> (3 << 2) is signed.
Huh?
Either you use the unshifted value "(define for) 3" with FIELD_PREP(),
or you use the shifted value "(define for) (3 << 2)" without FIELD_PREP()?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
