diff options
Diffstat (limited to 'Documentation/devicetree/bindings')
-rw-r--r-- | Documentation/devicetree/bindings/chosen.txt | 46 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/serial/pl011.txt | 28 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/unittest.txt | 14 |
3 files changed, 85 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt new file mode 100644 index 000000000000..ed838f453f7a --- /dev/null +++ b/Documentation/devicetree/bindings/chosen.txt @@ -0,0 +1,46 @@ +The chosen node +--------------- + +The chosen node does not represent a real device, but serves as a place +for passing data between firmware and the operating system, like boot +arguments. Data in the chosen node does not represent the hardware. + + +stdout-path property +-------------------- + +Device trees may specify the device to be used for boot console output +with a stdout-path property under /chosen, as described in ePAPR, e.g. + +/ { + chosen { + stdout-path = "/serial@f00:115200"; + }; + + serial@f00 { + compatible = "vendor,some-uart"; + reg = <0xf00 0x10>; + }; +}; + +If the character ":" is present in the value, this terminates the path. +The meaning of any characters following the ":" is device-specific, and +must be specified in the relevant binding documentation. + +For UART devices, the preferred binding is a string in the form: + + <baud>{<parity>{<bits>{<flow>}}} + +where + + baud - baud rate in decimal + parity - 'n' (none), 'o', (odd) or 'e' (even) + bits - number of data bits + flow - 'r' (rts) + +For example: 115200n8r + +Implementation note: Linux will look for the property "linux,stdout-path" or +on PowerPC "stdout" if "stdout-path" is not found. However, the +"linux,stdout-path" and "stdout" properties are deprecated. New platforms +should only use the "stdout-path" property. diff --git a/Documentation/devicetree/bindings/serial/pl011.txt b/Documentation/devicetree/bindings/serial/pl011.txt index 5d2e840ae65c..52464918cfe2 100644 --- a/Documentation/devicetree/bindings/serial/pl011.txt +++ b/Documentation/devicetree/bindings/serial/pl011.txt @@ -6,12 +6,34 @@ Required properties: - interrupts: exactly one interrupt specifier Optional properties: -- pinctrl: When present, must have one state named "sleep" - and one state named "default" -- clocks: When present, must refer to exactly one clock named +- pinctrl: When present, must have one state named "default", + and may contain a second name named "sleep". The former + state sets up pins for ordinary operation whereas + the latter state will put the associated pins to sleep + when the UART is unused +- clocks: When present, the first clock listed must correspond to + the clock named UARTCLK on the IP block, i.e. the clock + to the external serial line, whereas the second clock + must correspond to the PCLK clocking the internal logic + of the block. Just listing one clock (the first one) is + deprecated. +- clocks-names: When present, the first clock listed must be named + "uartclk" and the second clock listed must be named "apb_pclk" - dmas: When present, may have one or two dma channels. The first one must be named "rx", the second one must be named "tx". See also bindings/arm/primecell.txt + +Example: + +uart@80120000 { + compatible = "arm,pl011", "arm,primecell"; + reg = <0x80120000 0x1000>; + interrupts = <0 11 IRQ_TYPE_LEVEL_HIGH>; + dmas = <&dma 13 0 0x2>, <&dma 13 0 0x0>; + dma-names = "rx", "tx"; + clocks = <&foo_clk>, <&bar_clk>; + clock-names = "uartclk", "apb_pclk"; +}; diff --git a/Documentation/devicetree/bindings/unittest.txt b/Documentation/devicetree/bindings/unittest.txt new file mode 100644 index 000000000000..0f92a22fddfa --- /dev/null +++ b/Documentation/devicetree/bindings/unittest.txt @@ -0,0 +1,14 @@ +* OF selftest platform device + +** selftest + +Required properties: +- compatible: must be "selftest" + +All other properties are optional. + +Example: + selftest { + compatible = "selftest"; + status = "okay"; + }; |