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-rw-r--r--Documentation/devicetree/bindings/serial/8250.txt2
-rw-r--r--Documentation/devicetree/bindings/serial/st,stm32-usart.txt46
-rw-r--r--Documentation/kernel-parameters.txt11
3 files changed, 54 insertions, 5 deletions
diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index 936ab5b87324..f86bb06c39e9 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -42,6 +42,8 @@ Optional properties:
- auto-flow-control: one way to enable automatic flow control support. The
driver is allowed to detect support for the capability even without this
property.
+- tx-threshold: Specify the TX FIFO low water indication for parts with
+ programmable TX FIFO thresholds.
Note:
* fsl,ns16550:
diff --git a/Documentation/devicetree/bindings/serial/st,stm32-usart.txt b/Documentation/devicetree/bindings/serial/st,stm32-usart.txt
new file mode 100644
index 000000000000..85ec5f2b1996
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/st,stm32-usart.txt
@@ -0,0 +1,46 @@
+* STMicroelectronics STM32 USART
+
+Required properties:
+- compatible: Can be either "st,stm32-usart", "st,stm32-uart",
+"st,stm32f7-usart" or "st,stm32f7-uart" depending on whether
+the device supports synchronous mode and is compatible with
+stm32(f4) or stm32f7.
+- reg: The address and length of the peripheral registers space
+- interrupts: The interrupt line of the USART instance
+- clocks: The input clock of the USART instance
+
+Optional properties:
+- pinctrl: The reference on the pins configuration
+- st,hw-flow-ctrl: bool flag to enable hardware flow control.
+- dmas: phandle(s) to DMA controller node(s). Refer to stm32-dma.txt
+- dma-names: "rx" and/or "tx"
+
+Examples:
+usart4: serial@40004c00 {
+ compatible = "st,stm32-uart";
+ reg = <0x40004c00 0x400>;
+ interrupts = <52>;
+ clocks = <&clk_pclk1>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_usart4>;
+};
+
+usart2: serial@40004400 {
+ compatible = "st,stm32-usart", "st,stm32-uart";
+ reg = <0x40004400 0x400>;
+ interrupts = <38>;
+ clocks = <&clk_pclk1>;
+ st,hw-flow-ctrl;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_usart2 &pinctrl_usart2_rtscts>;
+};
+
+usart1: serial@40011000 {
+ compatible = "st,stm32-usart", "st,stm32-uart";
+ reg = <0x40011000 0x400>;
+ interrupts = <37>;
+ clocks = <&rcc 0 164>;
+ dmas = <&dma2 2 4 0x414 0x0>,
+ <&dma2 7 4 0x414 0x0>;
+ dma-names = "rx", "tx";
+};
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 25037ded3683..0e285941e3c7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1054,11 +1054,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
determined by the stdout-path property in device
tree's chosen node.
- cdns,<addr>
- Start an early, polled-mode console on a cadence serial
- port at the specified address. The cadence serial port
- must already be setup and configured. Options are not
- yet supported.
+ cdns,<addr>[,options]
+ Start an early, polled-mode console on a Cadence
+ (xuartps) serial port at the specified address. Only
+ supported option is baud rate. If baud rate is not
+ specified, the serial port must already be setup and
+ configured.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]