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>

1 files changed, 67 insertions, 0 deletions

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 000000000000..9e331777c203
--- /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@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";
+};