summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/serial/mvebu-uart.txt
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--Documentation/devicetree/bindings/serial/mvebu-uart.txt56
1 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/serial/mvebu-uart.txt b/Documentation/devicetree/bindings/serial/mvebu-uart.txt
new file mode 100644
index 000000000..a062bbca5
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/mvebu-uart.txt
@@ -0,0 +1,56 @@
+* Marvell UART : Non standard UART used in some of Marvell EBU SoCs
+ e.g., Armada-3700.
+
+Required properties:
+- compatible:
+ - "marvell,armada-3700-uart" for the standard variant of the UART
+ (32 bytes FIFO, no DMA, level interrupts, 8-bit access to the
+ FIFO), called also UART1.
+ - "marvell,armada-3700-uart-ext" for the extended variant of the
+ UART (128 bytes FIFO, DMA, front interrupts, 8-bit or 32-bit
+ accesses to the FIFO), called also UART2.
+- reg: offset and length of the register set for the device.
+- clocks: UART reference clock used to derive the baudrate. If no clock
+ is provided (possible only with the "marvell,armada-3700-uart"
+ compatible string for backward compatibility), it will only work
+ if the baudrate was initialized by the bootloader and no baudrate
+ change will then be possible. When provided it should be UART1-clk
+ for standard variant of UART and UART2-clk for extended variant
+ of UART. TBG clock (with UART TBG divisors d1=d2=1) or xtal clock
+ should not be used and are supported only for backward compatibility.
+- interrupts:
+ - Must contain three elements for the standard variant of the IP
+ (marvell,armada-3700-uart): "uart-sum", "uart-tx" and "uart-rx",
+ respectively the UART sum interrupt, the UART TX interrupt and
+ UART RX interrupt. A corresponding interrupt-names property must
+ be defined.
+ - Must contain two elements for the extended variant of the IP
+ (marvell,armada-3700-uart-ext): "uart-tx" and "uart-rx",
+ respectively the UART TX interrupt and the UART RX interrupt. A
+ corresponding interrupt-names property must be defined.
+ - For backward compatibility reasons, a single element interrupts
+ property is also supported for the standard variant of the IP,
+ containing only the UART sum interrupt. This form is deprecated
+ and should no longer be used.
+
+Example:
+ uart0: serial@12000 {
+ compatible = "marvell,armada-3700-uart";
+ reg = <0x12000 0x18>;
+ clocks = <&uartclk 0>;
+ interrupts =
+ <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-names = "uart-sum", "uart-tx", "uart-rx";
+ };
+
+ uart1: serial@12200 {
+ compatible = "marvell,armada-3700-uart-ext";
+ reg = <0x12200 0x30>;
+ clocks = <&uartclk 1>;
+ interrupts =
+ <GIC_SPI 30 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 31 IRQ_TYPE_EDGE_RISING>;
+ interrupt-names = "uart-tx", "uart-rx";
+ };