xref: /freebsd/sys/contrib/device-tree/Bindings/serial/mvebu-uart.txt (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1* Marvell UART : Non standard UART used in some of Marvell EBU SoCs
2                 e.g., Armada-3700.
3
4Required properties:
5- compatible:
6    - "marvell,armada-3700-uart" for the standard variant of the UART
7      (32 bytes FIFO, no DMA, level interrupts, 8-bit access to the
8      FIFO), called also UART1.
9    - "marvell,armada-3700-uart-ext" for the extended variant of the
10      UART (128 bytes FIFO, DMA, front interrupts, 8-bit or 32-bit
11      accesses to the FIFO), called also UART2.
12- reg: offset and length of the register set for the device.
13- clocks: UART reference clock used to derive the baudrate. If no clock
14      is provided (possible only with the "marvell,armada-3700-uart"
15      compatible string for backward compatibility), it will only work
16      if the baudrate was initialized by the bootloader and no baudrate
17      change will then be possible. When provided it should be UART1-clk
18      for standard variant of UART and UART2-clk for extended variant
19      of UART. TBG clock (with UART TBG divisors d1=d2=1) or xtal clock
20      should not be used and are supported only for backward compatibility.
21- interrupts:
22    - Must contain three elements for the standard variant of the IP
23      (marvell,armada-3700-uart): "uart-sum", "uart-tx" and "uart-rx",
24      respectively the UART sum interrupt, the UART TX interrupt and
25      UART RX interrupt. A corresponding interrupt-names property must
26      be defined.
27    - Must contain two elements for the extended variant of the IP
28      (marvell,armada-3700-uart-ext): "uart-tx" and "uart-rx",
29      respectively the UART TX interrupt and the UART RX interrupt. A
30      corresponding interrupt-names property must be defined.
31    - For backward compatibility reasons, a single element interrupts
32      property is also supported for the standard variant of the IP,
33      containing only the UART sum interrupt. This form is deprecated
34      and should no longer be used.
35
36Example:
37	uart0: serial@12000 {
38		compatible = "marvell,armada-3700-uart";
39		reg = <0x12000 0x18>;
40		clocks = <&uartclk 0>;
41		interrupts =
42		<GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>,
43		<GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>,
44		<GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
45		interrupt-names = "uart-sum", "uart-tx", "uart-rx";
46	};
47
48	uart1: serial@12200 {
49		compatible = "marvell,armada-3700-uart-ext";
50		reg = <0x12200 0x30>;
51		clocks = <&uartclk 1>;
52		interrupts =
53		<GIC_SPI 30 IRQ_TYPE_EDGE_RISING>,
54		<GIC_SPI 31 IRQ_TYPE_EDGE_RISING>;
55		interrupt-names = "uart-tx", "uart-rx";
56	};
57