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Diffstat (limited to 'Documentation/devicetree/bindings/net/can/fsl-flexcan.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/net/can/fsl-flexcan.txt | 63 |
1 files changed, 13 insertions, 50 deletions
diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt index 1a729f089866..1ad80d5865a9 100644 --- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt +++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt @@ -1,61 +1,24 @@ -CAN Device Tree Bindings ------------------------- -2011 Freescale Semiconductor, Inc. +Flexcan CAN contoller on Freescale's ARM and PowerPC system-on-a-chip (SOC). -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. +Required properties: -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. +- compatible : Should be "fsl,<processor>-flexcan" -Can Engine Clock Source - There are two sources for CAN clock - - Platform Clock It represents the bus clock - - Oscillator Clock + An implementation should also claim any of the following compatibles + that it is fully backwards compatible with: - Peripheral Clock (PLL) - -------------- - | - --------- ------------- - | |CPI Clock | Prescaler | Sclock - | |---------------->| (1.. 256) |------------> - --------- ------------- - | | - -------------- ---------------------CLK_SRC - Oscillator Clock + - fsl,p1010-flexcan -- 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). +- reg : Offset and length of the register set for this device +- interrupts : Interrupt tuple for this device +- clock-frequency : The oscillator frequency driving the flexcan device -- 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. +Example: -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"; + can@1c000 { + compatible = "fsl,p1010-flexcan"; reg = <0x1c000 0x1000>; interrupts = <48 0x2>; interrupt-parent = <&mpic>; - fsl,flexcan-clock-source = "platform"; - fsl,flexcan-clock-divider = <2>; - clock-frequency = <fixed by u-boot>; + clock-frequency = <200000000>; // filled in by bootloader }; |