Add DT binding documentation for the Linux driver for the SiFive
PRCI clock & reset control IP block, as found on the SiFive
FU540 chip.

Cc: Michael Turquette <mturque...@baylibre.com>
Cc: Stephen Boyd <sb...@kernel.org>
Cc: Rob Herring <robh...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Palmer Dabbelt <pal...@sifive.com>
Cc: Megan Wachs <me...@sifive.com>                                              
                                                                      Cc: 
linux-...@vger.kernel.org
Cc: devicet...@vger.kernel.org
Cc: linux-ri...@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul Walmsley <paul.walms...@sifive.com>
Signed-off-by: Paul Walmsley <p...@pwsan.com>
---
 .../bindings/clock/sifive/fu540-prci.txt      | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 
Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt

diff --git a/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt 
b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt
new file mode 100644
index 000000000000..27d8fdd4f3a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt
@@ -0,0 +1,40 @@
+SiFive FU540 PRCI bindings
+
+On the FU540 family of SoCs, most system-wide clock and reset integration
+is via the PRCI IP block.
+
+Required properties:
+- compatible: Should be "sifive,fu540-c000-prci0"
+- reg: Should describe the PRCI's register target physical address region
+- clocks: Should point to the hfclk device tree node and the rtcclk
+          device tree node.  The RTC clock here is not a time-of-day clock,
+         but is instead a high-stability clock source for system timers
+         and cycle counters.
+- #clock-cells: Should be <1>
+
+The clock consumer should specify the desired clock via the clock ID
+macros defined in include/linux/clk/sifive-fu540-prci.h.  These macros
+begin with PRCI_CLK_.
+
+
+
+Examples:
+
+hfclk: hfclk {
+       #clock-cells = <0>;
+       compatible = "fixed-clock";
+       clock-frequency = <33333333>;
+       clock-output-names = "hfclk";
+};
+rtcclk: rtcclk {
+       #clock-cells = <0>;
+       compatible = "fixed-clock";
+       clock-frequency = <1000000>;
+       clock-output-names = "rtcclk";
+};
+prci0: prci@10000000 {
+       compatible = "sifive,fu540-c000-prci0", "sifive,prci0";
+       reg = <0x0 0x10000000 0x0 0x1000>;
+       clocks = <&hfclk>, <&rtcclk>;
+       #clock-cells = <1>;
+};
-- 
2.19.1

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