Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
1 * Synopsys DesignWare ABP UART 2 3 Required properties: 4 - compatible : "snps,dw-apb-uart" 5 - reg : offset and length of the register set for the device. 6 - interrupts : should contain uart interrupt. 7 8 Clock handling: 9 The clock rate of the input clock needs to be supplied by one of 10 - clock-frequency : the input clock frequency for the UART. 11 - clocks : phandle to the input clock 12 13 The supplying peripheral clock can also be handled, needing a second property 14 - clock-names: tuple listing input clock names. 15 Required elements: "baudclk", "apb_pclk" 16 17 Optional properties: 18 - snps,uart-16550-compatible : reflects the value of UART_16550_COMPATIBLE 19 configuration parameter. Define this if your UART does not implement the busy 20 functionality. 21 - resets : phandle to the parent reset controller. 22 - reg-shift : quantity to shift the register offsets by. If this property is 23 not present then the register offsets are not shifted. 24 - reg-io-width : the size (in bytes) of the IO accesses that should be 25 performed on the device. If this property is not present then single byte 26 accesses are used. 27 - dcd-override : Override the DCD modem status signal. This signal will always 28 be reported as active instead of being obtained from the modem status 29 register. Define this if your serial port does not use this pin. 30 - dsr-override : Override the DTS modem status signal. This signal will always 31 be reported as active instead of being obtained from the modem status 32 register. Define this if your serial port does not use this pin. 33 - cts-override : Override the CTS modem status signal. This signal will always 34 be reported as active instead of being obtained from the modem status 35 register. Define this if your serial port does not use this pin. 36 - ri-override : Override the RI modem status signal. This signal will always be 37 reported as inactive instead of being obtained from the modem status register. 38 Define this if your serial port does not use this pin. 39 40 Example: 41 42 uart@80230000 { 43 compatible = "snps,dw-apb-uart"; 44 reg = <0x80230000 0x100>; 45 clock-frequency = <3686400>; 46 interrupts = <10>; 47 reg-shift = <2>; 48 reg-io-width = <4>; 49 dcd-override; 50 dsr-override; 51 cts-override; 52 ri-override; 53 }; 54 55 Example with one clock: 56 57 uart@80230000 { 58 compatible = "snps,dw-apb-uart"; 59 reg = <0x80230000 0x100>; 60 clocks = <&baudclk>; 61 interrupts = <10>; 62 reg-shift = <2>; 63 reg-io-width = <4>; 64 }; 65 66 Example with two clocks: 67 68 uart@80230000 { 69 compatible = "snps,dw-apb-uart"; 70 reg = <0x80230000 0x100>; 71 clocks = <&baudclk>, <&apb_pclk>; 72 clock-names = "baudclk", "apb_pclk"; 73 interrupts = <10>; 74 reg-shift = <2>; 75 reg-io-width = <4>; 76 };