Re: [PATCH v3 1/2] can: m_can: add device tree binding documentation

[Varka Bhadram <varkabhadram@gmail.com>]

On 07/11/2014 03:59 PM, Dong Aisheng wrote:
> add M_CAN device tree binding documentation
>
> Cc: Wolfgang Grandegger <wg@grandegger.com>
> Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Oliver Hartkopp <socketcan@hartkopp.net>
> Cc: Varka Bhadram <varkabhadram@gmail.com>
> Signed-off-by: Dong Aisheng <b29396@freescale.com>
> ---
>   .../devicetree/bindings/net/can/m_can.txt          |   65 ++++++++++++++++++++
>   1 files changed, 65 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..c4cb263
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/can/m_can.txt
> @@ -0,0 +1,65 @@
> +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

I think this should be pinctrl-0

> +- pinctrl-names		: Names corresponding to the numbered pinctrl states

remove 1 tab space before :

> +- 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.
> +

It may written like:
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,
			  ...

> +  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@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";
> +	mram-cfg = <0x0 0 0 32 0 0 0 1>;
> +	status = "disabled";
> +};
> +
> +Board dtsi:
> +&m_can1 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pinctrl_m_can1>;
> +	status = "enabled";
> +};


-- 
Regards,
Varka Bhadram.