From: Biju Das <biju.das.jz@bp.renesas.com>

Update RCANFD_CFG_* macros to give a meaning to the magic number using
GENMASK macro and extract the values using FIELD_PREP macro.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v1->v2:
 * Moved from patch#4 to patch#2.
 * Updated commit header and description.
 * Kept RCANFD_CFG* macro definitions to give a meaning to the magic
   number using GENMASK macro and used FIELD_PREP to extract value.
---
 drivers/net/can/rcar/rcar_canfd.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index ce355f79e6b6..8bae25758924 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -103,10 +103,10 @@
 /* Channel register bits */
 
 /* RSCFDnCmCFG - Classical CAN only */
-#define RCANFD_CFG_SJW(x)		(((x) & 0x3) << 24)
-#define RCANFD_CFG_TSEG2(x)		(((x) & 0x7) << 20)
-#define RCANFD_CFG_TSEG1(x)		(((x) & 0xf) << 16)
-#define RCANFD_CFG_BRP(x)		(((x) & 0x3ff) << 0)
+#define RCANFD_CFG_SJW_MASK		GENMASK(25, 24)
+#define RCANFD_CFG_TSEG2_MASK		GENMASK(22, 20)
+#define RCANFD_CFG_TSEG1_MASK		GENMASK(19, 16)
+#define RCANFD_CFG_BRP_MASK		GENMASK(9, 0)
 
 /* RSCFDnCFDCmNCFG - CAN FD only */
 #define RCANFD_NCFG_NTSEG2(gpriv, x) \
@@ -1416,8 +1416,10 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		cfg = (RCANFD_NCFG_NTSEG1(gpriv, tseg1) | RCANFD_NCFG_NBRP(brp) |
 		       RCANFD_NCFG_NSJW(gpriv, sjw) | RCANFD_NCFG_NTSEG2(gpriv, tseg2));
 	} else {
-		cfg = (RCANFD_CFG_TSEG1(tseg1) | RCANFD_CFG_BRP(brp) |
-		       RCANFD_CFG_SJW(sjw) | RCANFD_CFG_TSEG2(tseg2));
+		cfg = FIELD_PREP(RCANFD_CFG_TSEG1_MASK, tseg1) |
+		      FIELD_PREP(RCANFD_CFG_BRP_MASK, brp) |
+		      FIELD_PREP(RCANFD_CFG_SJW_MASK, sjw) |
+		      FIELD_PREP(RCANFD_CFG_TSEG2_MASK, tseg2);
 	}
 
 	rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
-- 
2.43.0

Hi Biju,

On Thu, 21 Aug 2025 at 16:14, Biju <biju.das.au@gmail.com> wrote:
> From: Biju Das <biju.das.jz@bp.renesas.com>
>
> Update RCANFD_CFG_* macros to give a meaning to the magic number using
> GENMASK macro and extract the values using FIELD_PREP macro.
>
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> v1->v2:
>  * Moved from patch#4 to patch#2.
>  * Updated commit header and description.
>  * Kept RCANFD_CFG* macro definitions to give a meaning to the magic
>    number using GENMASK macro and used FIELD_PREP to extract value.

> --- a/drivers/net/can/rcar/rcar_canfd.c
> +++ b/drivers/net/can/rcar/rcar_canfd.c
> @@ -103,10 +103,10 @@
>  /* Channel register bits */
>
>  /* RSCFDnCmCFG - Classical CAN only */
> -#define RCANFD_CFG_SJW(x)              (((x) & 0x3) << 24)
> -#define RCANFD_CFG_TSEG2(x)            (((x) & 0x7) << 20)
> -#define RCANFD_CFG_TSEG1(x)            (((x) & 0xf) << 16)
> -#define RCANFD_CFG_BRP(x)              (((x) & 0x3ff) << 0)
> +#define RCANFD_CFG_SJW_MASK            GENMASK(25, 24)
> +#define RCANFD_CFG_TSEG2_MASK          GENMASK(22, 20)
> +#define RCANFD_CFG_TSEG1_MASK          GENMASK(19, 16)
> +#define RCANFD_CFG_BRP_MASK            GENMASK(9, 0)

Upon a second look, I would drop the "_MASK" suffix.

>
>  /* RSCFDnCFDCmNCFG - CAN FD only */
>  #define RCANFD_NCFG_NTSEG2(gpriv, x) \

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@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

On Thu, 21 Aug 2025 at 16:14, Biju <biju.das.au@gmail.com> wrote:
> From: Biju Das <biju.das.jz@bp.renesas.com>
>
> Update RCANFD_CFG_* macros to give a meaning to the magic number using
> GENMASK macro and extract the values using FIELD_PREP macro.
>
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> v1->v2:
>  * Moved from patch#4 to patch#2.
>  * Updated commit header and description.
>  * Kept RCANFD_CFG* macro definitions to give a meaning to the magic
>    number using GENMASK macro and used FIELD_PREP to extract value.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@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