On Wed, Aug 10, 2011 at 03:47:43PM +0200, Wolfgang Grandegger wrote:
> Hi Robin,
>
> On 08/10/2011 05:06 AM, Robin Holt wrote:
> > In working with the socketcan developers, we have come to the conclusion
> > the Documentation...fsl-flexcan.txt device tree documentation needs to
> > be cleaned up. The driver does not depend upon any properties other
>
> Your first sentence could be misleading. Please just describe what the
> patch does and why, something like:
>
> "This patch cleans up the documentation of the device-tree binding for
> the Flexcan devices on Freescale's PowerPC and ARM cores. Extra
> properties are not needed as the frequency of the source clock is
> fixed..." and so on.
I borrowed heavily from your message. ;)
> > than the required properties so we are removing the file. Additionally,
> > the p1010*dts* files are not following the standard for node naming in
> > that they have a trailing -v1.0.
>
> > Signed-off-by: Robin Holt <h...@sgi.com>
> > To: Marc Kleine-Budde <m...@pengutronix.de>,
> > To: Wolfgang Grandegger <w...@grandegger.com>,
> > To: U Bhaskar-B22300 <b22...@freescale.com>
> > To: Scott Wood <scottw...@freescale.com>
> > Cc: socketcan-c...@lists.berlios.de,
> > Cc: net...@vger.kernel.org,
> > Cc: PPC list <linuxppc-dev@lists.ozlabs.org>
> > Cc: Kumar Gala <ga...@kernel.crashing.org>
> > ---
> > .../devicetree/bindings/net/can/fsl-flexcan.txt | 61
> > --------------------
> > arch/powerpc/boot/dts/p1010rdb.dts | 8 ---
> > arch/powerpc/boot/dts/p1010si.dtsi | 8 +-
> > 3 files changed, 4 insertions(+), 73 deletions(-)
> > delete mode 100644
> > Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> >
> > diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> > b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> > deleted file mode 100644
> > index 1a729f0..0000000
> > --- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> > +++ /dev/null
> > @@ -1,61 +0,0 @@
> > -CAN Device Tree Bindings
> > -------------------------
> > -2011 Freescale Semiconductor, Inc.
> > -
> > -fsl,flexcan-v1.0 nodes
> > ------------------------
> > -In addition to the required compatible-, reg- and interrupt-properties,
> > you can
> > -also specify which clock source shall be used for the controller.
> > -
> > -CPI Clock- Can Protocol Interface Clock
> > - This CLK_SRC bit of CTRL(control register) selects the clock source to
> > - the CAN Protocol Interface(CPI) to be either the peripheral clock
> > - (driven by the PLL) or the crystal oscillator clock. The selected clock
> > - is the one fed to the prescaler to generate the Serial Clock (Sclock).
> > - The PRESDIV field of CTRL(control register) controls a prescaler that
> > - generates the Serial Clock (Sclock), whose period defines the
> > - time quantum used to compose the CAN waveform.
> > -
> > -Can Engine Clock Source
> > - There are two sources for CAN clock
> > - - Platform Clock It represents the bus clock
> > - - Oscillator Clock
> > -
> > - Peripheral Clock (PLL)
> > - --------------
> > - |
> > - --------- -------------
> > - | |CPI Clock | Prescaler | Sclock
> > - | |---------------->| (1.. 256) |------------>
> > - --------- -------------
> > - | |
> > - -------------- ---------------------CLK_SRC
> > - Oscillator Clock
> > -
> > -- fsl,flexcan-clock-source : CAN Engine Clock Source.This property selects
> > - the peripheral clock. PLL clock is fed to the
> > - prescaler to generate the Serial Clock (Sclock).
> > - Valid values are "oscillator" and "platform"
> > - "oscillator": CAN engine clock source is
> > oscillator clock.
> > - "platform" The CAN engine clock source is the bus
> > clock
> > - (platform clock).
> > -
> > -- fsl,flexcan-clock-divider : for the reference and system clock, an
> > additional
> > - clock divider can be specified.
> > -- clock-frequency: frequency required to calculate the bitrate for FlexCAN.
> > -
> > -Note:
> > - - v1.0 of flexcan-v1.0 represent the IP block version for P1010 SOC.
> > - - P1010 does not have oscillator as the Clock Source.So the default
> > - Clock Source is platform clock.
> > -Examples:
> > -
> > - can0@1c000 {
> > - compatible = "fsl,flexcan-v1.0";
> > - reg = <0x1c000 0x1000>;
> > - interrupts = <48 0x2>;
> > - interrupt-parent = <&mpic>;
> > - fsl,flexcan-clock-source = "platform";
> > - fsl,flexcan-clock-divqider = <2>;
> > - clock-frequency = <fixed by u-boot>;
> > - };
>
> Do we really want to drop the documentation for that binding. I think
> something like the following text would be still useful:
>
> ------------------------
> Flexcan CAN contoller on Freescale's ARM and PowerPC processors
>
> Required properties:
>
> - compatible : Should be "fsl,flexcan" and optionally
> "fsl,flexcan-<processor>"
> - reg : Offset and length of the register set for this device
> - interrupts : Interrupt tuple for this device
>
> Example:
>
> can@1c000 {
> compatible = "fsl,p1010-flexcan", "fsl,flexcan";
> reg = <0x1c000 0x1000>;
> interrupts = <48 0x2>;
> interrupt-parent = <&mpic>;
> };
> -------------------------
Done, except the
> compatible = "fsl,p1010-flexcan", "fsl,flexcan";
line is
compatible = "fsl,flexcan", "fsl,flexcan-p1010";
>
> What do you think?
>
> > diff --git a/arch/powerpc/boot/dts/p1010rdb.dts
> > b/arch/powerpc/boot/dts/p1010rdb.dts
> > index 6b33b73..d6a0bb2 100644
> > --- a/arch/powerpc/boot/dts/p1010rdb.dts
> > +++ b/arch/powerpc/boot/dts/p1010rdb.dts
> > @@ -169,14 +169,6 @@
> > };
> > };
> >
> > - can0@1c000 {
> > - fsl,flexcan-clock-source = "platform";
> > - };
> > -
> > - can1@1d000 {
> > - fsl,flexcan-clock-source = "platform";
> > - };
> > -
> > usb@22000 {
> > phy_type = "utmi";
> > };
> > diff --git a/arch/powerpc/boot/dts/p1010si.dtsi
> > b/arch/powerpc/boot/dts/p1010si.dtsi
> > index 7f51104..20c396d 100644
> > --- a/arch/powerpc/boot/dts/p1010si.dtsi
> > +++ b/arch/powerpc/boot/dts/p1010si.dtsi
> > @@ -141,19 +141,19 @@
> > };
> >
> > can0@1c000 {
> > - compatible = "fsl,flexcan-v1.0";
> > + compatible = "fsl,p1010-flexcan",
> > + "fsl,flexcan";
>
> Does fit on one line.
>
> > reg = <0x1c000 0x1000>;
> > interrupts = <48 0x2>;
> > interrupt-parent = <&mpic>;
> > - fsl,flexcan-clock-divider = <2>;
> > };
> >
> > can1@1d000 {
> > - compatible = "fsl,flexcan-v1.0";
> > + compatible = "fsl,p1010-flexcan",
> > + "fsl,flexcan";
>
> Ditto
>
> > reg = <0x1d000 0x1000>;
> > interrupts = <61 0x2>;
> > interrupt-parent = <&mpic>;
> > - fsl,flexcan-clock-divider = <2>;
> > };
> >
> > L2: l2-cache-controller@20000 {
>
> Please also correct the node names (not using the number suffix).
So the node names should be
can@1c000 {
can@1d000 {
correct?
Robin
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