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can: m_can: add device tree binding documentation 

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>
Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Dong Aisheng 2014-07-16 17:30:49 +08:00 committed by Marc Kleine-Budde
parent cdce844865
commit e35430807d
1 changed files with 67 additions and 0 deletions
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Documentation/devicetree/bindings/net/can/m_can.txt Normal file
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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@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 dts:
&m_can1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_m_can1>;
status = "enabled";
};