This change adds DT bindings documentation for device nodes with compatible
string "marvell,armada-3700-uart-clock".
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
---
.../bindings/clock/armada3700-uart-clock.txt | 24 +++++++++++++++++++
.../devicetree/bindings/serial/mvebu-uart.txt | 9 ++++---
2 files changed, 30 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/clock/armada3700-uart-clock.txt
diff --git a/Documentation/devicetree/bindings/clock/armada3700-uart-clock.txt b/Documentation/devicetree/bindings/clock/armada3700-uart-clock.txt
new file mode 100644
index 000000000000..144bc6d7eae8
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/armada3700-uart-clock.txt
@@ -0,0 +1,24 @@
+* Marvell Armada 3720 UART clocks
+
+Required properties:
+- compatible: "marvell,armada-3700-uart-clock"
+- reg: two 4-bytes registers: UART Clock Control and UART 2 Baud Rate Divisor
+- #clock-cells : from common clock binding; shall be set to 1
+- clocks: List of parent clocks suitable for UART from following set:
+ "TBG-A-P", "TBG-B-P", "TBG-A-S", "TBG-B-S", "xtal"
+ UART clock can use one from this set and when more are provided
+ then kernel would choose and configure the most suitable one.
+ It is suggest to specify at least one TBG clock to achieve
+ baudrates above 230400 and also to specify clock which bootloader
+ used for UART (most probably xtal) for smooth boot log on UART.
+
+Example:
+ uartclk: uartclk@12000 {
+ compatible = "marvell,armada-3700-uart-clock";
+ reg = <0x12010 0x4>, <0x12210 0x4>;
+ clocks = <&tbg 0>, <&tbg 1>, <&tbg 2>,
+ <&tbg 3>, <&xtalclk>;
+ clock-names = "TBG-A-P", "TBG-B-P", "TBG-A-S",
+ "TBG-B-S", "xtal";
+ #clock-cells = <1>;
+ };
diff --git a/Documentation/devicetree/bindings/serial/mvebu-uart.txt b/Documentation/devicetree/bindings/serial/mvebu-uart.txt
index 2d0dbdf32d1d..463968e7e7f3 100644
--- a/Documentation/devicetree/bindings/serial/mvebu-uart.txt
+++ b/Documentation/devicetree/bindings/serial/mvebu-uart.txt
@@ -14,7 +14,10 @@ Required properties:
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.
+ 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 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",
@@ -34,7 +37,7 @@ Example:
uart0: serial@12000 {
compatible = "marvell,armada-3700-uart";
reg = <0x12000 0x18>;
- clocks = <&xtalclk>;
+ clocks = <&uartclk 0>;
interrupts =
<GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>,
@@ -45,7 +48,7 @@ Example:
uart1: serial@12200 {
compatible = "marvell,armada-3700-uart-ext";
reg = <0x12200 0x30>;
- clocks = <&xtalclk>;
+ clocks = <&uartclk 1>;
interrupts =
<GIC_SPI 30 IRQ_TYPE_EDGE_RISING>,
<GIC_SPI 31 IRQ_TYPE_EDGE_RISING>;
--
2.20.1
