| Message ID | 1456496023-16240-1-git-send-email-ramesh.shanmugasundaram@bp.renesas.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Hi Ramesh, On Fri, Feb 26, 2016 at 3:13 PM, Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> wrote: > Adds external CAN clock node for r8a7795. This clock can be used as > fCAN clock of CAN and CAN FD controller. > > Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> > --- > arch/arm64/boot/dts/renesas/r8a7795.dtsi | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi b/arch/arm64/boot/dts/renesas/r8a7795.dtsi > index a7315eb..5167a6c 100644 > --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi > +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi > @@ -115,6 +115,13 @@ > clock-frequency = <0>; > }; > > + /* External CAN clock - to be overridden by boards that provide it */ > + can_clk: can { > + compatible = "fixed-clock"; > + #clock-cells = <0>; > + clock-frequency = <0>; As this is an optional clock, it should have status = "disabled"; > + }; 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
Hi Geert, > On Fri, Feb 26, 2016 at 3:13 PM, Ramesh Shanmugasundaram > <ramesh.shanmugasundaram@bp.renesas.com> wrote: > > Adds external CAN clock node for r8a7795. This clock can be used as > > fCAN clock of CAN and CAN FD controller. > > > > Signed-off-by: Ramesh Shanmugasundaram > > <ramesh.shanmugasundaram@bp.renesas.com> > > --- > > arch/arm64/boot/dts/renesas/r8a7795.dtsi | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi > > b/arch/arm64/boot/dts/renesas/r8a7795.dtsi > > index a7315eb..5167a6c 100644 > > --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi > > +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi > > @@ -115,6 +115,13 @@ > > clock-frequency = <0>; > > }; > > > > + /* External CAN clock - to be overridden by boards that provide > it */ > > + can_clk: can { > > + compatible = "fixed-clock"; > > + #clock-cells = <0>; > > + clock-frequency = <0>; > > As this is an optional clock, it should have > > status = "disabled"; Yes, I too thought the same but the status property is not obeyed. The "disabled" clock still shows up in clk_tree and clk_xxx apis works just fine (Is this a DT bug?). Hence left the ambiguous "status". In code I use clk_get_rate(can_clk) != 0 to see if it's enabled, which seems logical. If you add this as a child of soc node, status property is obeyed. But all external clocks are defined outside soc (correctly) and I followed the same. Thanks, Ramesh Note: tests based on next-20160127
Hi Ramesh, On Fri, Feb 26, 2016 at 4:00 PM, Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> wrote: >> On Fri, Feb 26, 2016 at 3:13 PM, Ramesh Shanmugasundaram >> <ramesh.shanmugasundaram@bp.renesas.com> wrote: >> > --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi >> > +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi >> > @@ -115,6 +115,13 @@ >> > clock-frequency = <0>; >> > }; >> > >> > + /* External CAN clock - to be overridden by boards that provide >> it */ >> > + can_clk: can { >> > + compatible = "fixed-clock"; >> > + #clock-cells = <0>; >> > + clock-frequency = <0>; >> >> As this is an optional clock, it should have >> >> status = "disabled"; > > Yes, I too thought the same but the status property is not obeyed. The > "disabled" clock still shows up in clk_tree and clk_xxx apis works just fine > (Is this a DT bug?). Hence left the ambiguous "status". In code I use > clk_get_rate(can_clk) != 0 to see if it's enabled, which seems logical. > > If you add this as a child of soc node, status property is obeyed. But all > external clocks are defined outside soc (correctly) and I followed the same. You're right. That's clearly a bug. I sent a patch to fix that. 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
diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi b/arch/arm64/boot/dts/renesas/r8a7795.dtsi index a7315eb..5167a6c 100644 --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi @@ -115,6 +115,13 @@ clock-frequency = <0>; }; + /* External CAN clock - to be overridden by boards that provide it */ + can_clk: can { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <0>; + }; + /* External SCIF clock - to be overridden by boards that provide it */ scif_clk: scif { compatible = "fixed-clock";
Adds external CAN clock node for r8a7795. This clock can be used as fCAN clock of CAN and CAN FD controller. Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com> --- arch/arm64/boot/dts/renesas/r8a7795.dtsi | 7 +++++++ 1 file changed, 7 insertions(+)