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Diffstat (limited to 'Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt')
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diff --git a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt new file mode 100644 index 000000000..12bbe9f22 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.txt @@ -0,0 +1,76 @@ +* Synopsys DesignWare ABP UART + +Required properties: +- compatible : "snps,dw-apb-uart" +- reg : offset and length of the register set for the device. +- interrupts : should contain uart interrupt. + +Clock handling: +The clock rate of the input clock needs to be supplied by one of +- clock-frequency : the input clock frequency for the UART. +- clocks : phandle to the input clock + +The supplying peripheral clock can also be handled, needing a second property +- clock-names: tuple listing input clock names. + Required elements: "baudclk", "apb_pclk" + +Optional properties: +- snps,uart-16550-compatible : reflects the value of UART_16550_COMPATIBLE + configuration parameter. Define this if your UART does not implement the busy + functionality. +- resets : phandle to the parent reset controller. +- reg-shift : quantity to shift the register offsets by. If this property is + not present then the register offsets are not shifted. +- reg-io-width : the size (in bytes) of the IO accesses that should be + performed on the device. If this property is not present then single byte + accesses are used. +- dcd-override : Override the DCD modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- dsr-override : Override the DTS modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- cts-override : Override the CTS modem status signal. This signal will always + be reported as active instead of being obtained from the modem status + register. Define this if your serial port does not use this pin. +- ri-override : Override the RI modem status signal. This signal will always be + reported as inactive instead of being obtained from the modem status register. + Define this if your serial port does not use this pin. + +Example: + + uart@80230000 { + compatible = "snps,dw-apb-uart"; + reg = <0x80230000 0x100>; + clock-frequency = <3686400>; + interrupts = <10>; + reg-shift = <2>; + reg-io-width = <4>; + dcd-override; + dsr-override; + cts-override; + ri-override; + }; + +Example with one clock: + + uart@80230000 { + compatible = "snps,dw-apb-uart"; + reg = <0x80230000 0x100>; + clocks = <&baudclk>; + interrupts = <10>; + reg-shift = <2>; + reg-io-width = <4>; + }; + +Example with two clocks: + + uart@80230000 { + compatible = "snps,dw-apb-uart"; + reg = <0x80230000 0x100>; + clocks = <&baudclk>, <&apb_pclk>; + clock-names = "baudclk", "apb_pclk"; + interrupts = <10>; + reg-shift = <2>; + reg-io-width = <4>; + }; |