Add DT binding for the clock deleters in the TZ1090 SoC, which delete up
to 1023 out of every 1024 clock pulses of the input clock.
Signed-off-by: James Hogan <james.ho...@imgtec.com>
Cc: Mike Turquette <mturque...@linaro.org>
Cc: Rob Herring <robh...@kernel.org>
Cc: Pawel Moll <pawel.m...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Ian Campbell <ijc+devicet...@hellion.org.uk>
Cc: Kumar Gala <ga...@codeaurora.org>
Cc: linux-me...@vger.kernel.org
Cc: devicet...@vger.kernel.org
---
.../bindings/clock/img,tz1090-deleter.txt | 40 ++++++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644
Documentation/devicetree/bindings/clock/img,tz1090-deleter.txt
diff --git a/Documentation/devicetree/bindings/clock/img,tz1090-deleter.txt
b/Documentation/devicetree/bindings/clock/img,tz1090-deleter.txt
new file mode 100644
index 0000000..0f595be
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/img,tz1090-deleter.txt
@@ -0,0 +1,40 @@
+Binding for TZ1090 clock deleter.
+
+This binding uses the common clock binding[1]. The TZ1090 clock deleters can be
+configured to delete a certain fraction of the input clock pulses, so the
output
+frequency is:
+
+ deleted_cycles = (reg & bit_mask) >> bit_shift
+ f_out = f_in * (cycle_period - deleted_cycles) / cycle_period
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : Shall be "img,tz1090-deleter".
+- #clock-cells : From common clock binding; shall be set to 0.
+- reg : Address of configuration register.
+- bit-mask : Shift of config value field in configuration register.
+- clocks : From common clock binding.
+
+Required source clocks:
+- 0 : Reference clock which is deleted to produce the output
+ clock (doesn't have to be named).
+
+Optional properties:
+- clock-output-names : From common clock binding.
+- bit-shift : Number of bits to shift the bit-mask, defaults to
+ (ffs(mask) - 1) if not present.
+- cycle-period : Period from which clocks are deleted, defaults to
+ (1 << (fls(mask) - bit-shift)) if not present.
+
+Example:
+ meta_clkdelete {
+ compatible = "img,tz1090-deleter";
+ #clock-cells = <0>;
+ clocks = <&sys_clk_x2_undeleted>;
+ reg = <0x0200591c 0x4>;
+ bit-mask = <0x000003ff>;
+ /* implicit bit-shift = <0> */
+ /* implicit cycle-period = <1024> */
+ clock-output-names = "meta";
+ };
--
2.0.4
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