[PATCH v4 1/2] can: m_can: add device tree binding documentation
Dong Aisheng
b29396 at freescale.com
Mon Jul 14 19:26:35 PDT 2014
On Mon, Jul 14, 2014 at 01:52:09PM +0200, Marc Kleine-Budde wrote:
> On 07/14/2014 01:40 PM, Dong Aisheng wrote:
> > add M_CAN device tree binding documentation
> >
> > Cc: Wolfgang Grandegger <wg at grandegger.com>
> > Cc: Marc Kleine-Budde <mkl at pengutronix.de>
> > Cc: Mark Rutland <mark.rutland at arm.com>
> > Cc: Oliver Hartkopp <socketcan at hartkopp.net>
> > Cc: Varka Bhadram <varkabhadram at gmail.com>
> > Signed-off-by: Dong Aisheng <b29396 at freescale.com>
> > ---
> >
> > Changes since v3:
> > - change mram-cfg property name to bosch,mram-cfg
> > - indent change
> > ---
> > .../devicetree/bindings/net/can/m_can.txt | 67 ++++++++++++++++++++
> > 1 files changed, 67 insertions(+), 0 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/net/can/m_can.txt
> >
> > diff --git a/Documentation/devicetree/bindings/net/can/m_can.txt b/Documentation/devicetree/bindings/net/can/m_can.txt
> > new file mode 100644
> > index 0000000..5cff839
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/can/m_can.txt
> > @@ -0,0 +1,67 @@
> > +Bosch MCAN controller Device Tree Bindings
> > +-------------------------------------------------
> > +
> > +Required properties:
> > +- compatible : Should be "bosch,m_can" for M_CAN controllers
> > +- reg : physical base address and size of the M_CAN
> > + registers map and Message RAM
> > +- reg-names : Should be "m_can" and "message_ram"
> > +- interrupts : Should be the interrupt number of M_CAN interrupt
> > + line 0 and line 1, could be same if sharing
> > + the same interrupt.
> > +- interrupt-names : Should contain "int0" and "int1"
> > +- clocks : Clocks used by controller, should be host clock
> > + and CAN clock.
> > +- clock-names : Should contain "hclk" and "cclk"
> > +- pinctrl-<n> : Pinctrl states as described in bindings/pinctrl/pinctrl-bindings.txt
> > +- pinctrl-names : Names corresponding to the numbered pinctrl states
> > +- bosch,mram-cfg : Message RAM configuration data.
> > + Multiple M_CAN instances can share the same Message
> > + RAM and each element(e.g Rx FIFO or Tx Buffer and etc)
> > + number in Message RAM is also configurable,
> > + so this property is telling driver how the shared or
> > + private Message RAM are used by this M_CAN controller.
> > +
> > + The format should be as follows:
> > + <offset sidf_elems xidf_elems rxf0_elems rxf1_elems
> > + rxb_elems txe_elems txb_elems>
> > + The 'offset' is an address offset of the Message RAM
> > + where the following elements start from. This is
> > + usually set to 0x0 if you're using a private Message
> > + RAM. The remain cells are used to specify how many
> > + elements are used for each FIFO/Buffer.
> > +
> > + M_CAN includes the following elements according to user manual:
> > + 11-bit Filter 0-128 elements / 0-128 words
> > + 29-bit Filter 0-64 elements / 0-128 words
> > + Rx FIFO 0 0-64 elements / 0-1152 words
> > + Rx FIFO 1 0-64 elements / 0-1152 words
> > + Rx Buffers 0-64 elements / 0-1152 words
> > + Tx Event FIFO 0-32 elements / 0-64 words
> > + Tx Buffers 0-32 elements / 0-576 words
> > +
> > + Please refer to 2.4.1 Message RAM Configuration in
> > + Bosch M_CAN user manual for details.
> > +
> > +Example:
> > +SoC dtsi:
> > +m_can1: can at 020e8000 {
> > + compatible = "bosch,m_can";
> > + reg = <0x020e8000 0x4000>, <0x02298000 0x4000>;
> > + reg-names = "m_can", "message_ram";
> > + interrupts = <0 114 0x04>,
> > + <0 114 0x04>;
> > + interrupt-names = "int0", "int1";
> > + clocks = <&clks IMX6SX_CLK_CANFD>,
> > + <&clks IMX6SX_CLK_CANFD>;
> > + clock-names = "hclk", "cclk";
> > + bosch,mram-cfg = <0x0 0 0 32 0 0 0 1>;
> > + status = "disabled";
> > +};
> > +
> > +Board dtsi:
> ^^^^
>
> The board is typically a dts, isn't it?
>
IMX has board dtsi.
But yes, i could change to dts which is more common.
> > +&m_can1 {
> > + pinctrl-names = "default";
> > + pinctrl-0 = <&pinctrl_m_can1>;
> > + status = "enabled";
> > +};
> >
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Industrial Linux Solutions | Phone: +49-231-2826-924 |
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>
Regards
Dong Aisheng
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