xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/serial/snps-dw-apb-uart.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* Synopsys DesignWare ABP UART
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunRequired properties:
4*4882a593Smuzhiyun- compatible : "snps,dw-apb-uart"
5*4882a593Smuzhiyun- reg : offset and length of the register set for the device.
6*4882a593Smuzhiyun- interrupts : should contain uart interrupt.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunClock handling:
9*4882a593SmuzhiyunThe clock rate of the input clock needs to be supplied by one of
10*4882a593Smuzhiyun- clock-frequency : the input clock frequency for the UART.
11*4882a593Smuzhiyun- clocks : phandle to the input clock
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunThe supplying peripheral clock can also be handled, needing a second property
14*4882a593Smuzhiyun- clock-names: tuple listing input clock names.
15*4882a593Smuzhiyun	Required elements: "baudclk", "apb_pclk"
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunOptional properties:
18*4882a593Smuzhiyun- snps,uart-16550-compatible : reflects the value of UART_16550_COMPATIBLE
19*4882a593Smuzhiyun  configuration parameter. Define this if your UART does not implement the busy
20*4882a593Smuzhiyun  functionality.
21*4882a593Smuzhiyun- resets : phandle to the parent reset controller.
22*4882a593Smuzhiyun- reg-shift : quantity to shift the register offsets by.  If this property is
23*4882a593Smuzhiyun  not present then the register offsets are not shifted.
24*4882a593Smuzhiyun- reg-io-width : the size (in bytes) of the IO accesses that should be
25*4882a593Smuzhiyun  performed on the device.  If this property is not present then single byte
26*4882a593Smuzhiyun  accesses are used.
27*4882a593Smuzhiyun- dcd-override : Override the DCD modem status signal. This signal will always
28*4882a593Smuzhiyun  be reported as active instead of being obtained from the modem status
29*4882a593Smuzhiyun  register. Define this if your serial port does not use this pin.
30*4882a593Smuzhiyun- dsr-override : Override the DTS modem status signal. This signal will always
31*4882a593Smuzhiyun  be reported as active instead of being obtained from the modem status
32*4882a593Smuzhiyun  register. Define this if your serial port does not use this pin.
33*4882a593Smuzhiyun- cts-override : Override the CTS modem status signal. This signal will always
34*4882a593Smuzhiyun  be reported as active instead of being obtained from the modem status
35*4882a593Smuzhiyun  register. Define this if your serial port does not use this pin.
36*4882a593Smuzhiyun- ri-override : Override the RI modem status signal. This signal will always be
37*4882a593Smuzhiyun  reported as inactive instead of being obtained from the modem status register.
38*4882a593Smuzhiyun  Define this if your serial port does not use this pin.
39*4882a593Smuzhiyun
40*4882a593SmuzhiyunExample:
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun	uart@80230000 {
43*4882a593Smuzhiyun		compatible = "snps,dw-apb-uart";
44*4882a593Smuzhiyun		reg = <0x80230000 0x100>;
45*4882a593Smuzhiyun		clock-frequency = <3686400>;
46*4882a593Smuzhiyun		interrupts = <10>;
47*4882a593Smuzhiyun		reg-shift = <2>;
48*4882a593Smuzhiyun		reg-io-width = <4>;
49*4882a593Smuzhiyun		dcd-override;
50*4882a593Smuzhiyun		dsr-override;
51*4882a593Smuzhiyun		cts-override;
52*4882a593Smuzhiyun		ri-override;
53*4882a593Smuzhiyun	};
54*4882a593Smuzhiyun
55*4882a593SmuzhiyunExample with one clock:
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun	uart@80230000 {
58*4882a593Smuzhiyun		compatible = "snps,dw-apb-uart";
59*4882a593Smuzhiyun		reg = <0x80230000 0x100>;
60*4882a593Smuzhiyun		clocks = <&baudclk>;
61*4882a593Smuzhiyun		interrupts = <10>;
62*4882a593Smuzhiyun		reg-shift = <2>;
63*4882a593Smuzhiyun		reg-io-width = <4>;
64*4882a593Smuzhiyun	};
65*4882a593Smuzhiyun
66*4882a593SmuzhiyunExample with two clocks:
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun	uart@80230000 {
69*4882a593Smuzhiyun		compatible = "snps,dw-apb-uart";
70*4882a593Smuzhiyun		reg = <0x80230000 0x100>;
71*4882a593Smuzhiyun		clocks = <&baudclk>, <&apb_pclk>;
72*4882a593Smuzhiyun		clock-names = "baudclk", "apb_pclk";
73*4882a593Smuzhiyun		interrupts = <10>;
74*4882a593Smuzhiyun		reg-shift = <2>;
75*4882a593Smuzhiyun		reg-io-width = <4>;
76*4882a593Smuzhiyun	};
77