> -----Original Message----- > From: Robin Holt [mailto:h...@sgi.com] > Sent: Wednesday, August 10, 2011 7:46 PM > To: Wolfgang Grandegger > Cc: Robin Holt; Marc Kleine-Budde; U Bhaskar-B22300; Wood Scott-B07421; > net...@vger.kernel.org; Kumar Gala; socketcan-c...@lists.berlios.de; PPC > list > Subject: Re: [PATCH v10 5/5] [powerpc] Fix up fsl-flexcan device tree > binding. > > 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? > [Bhaskar] As there are two CAN controllers on P1010,So won't it be better to distinguish it by can0 and can1 instead by simple "can" ? > Robin
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