CLK: TI: add support for clockdomain binding

Some OMAP clocks require knowledge about their parent clockdomain for
book keeping purposes. This patch creates a new DT binding for TI
clockdomains, which act as a collection of device clocks. Clockdomain
itself is rather misleading name for the hardware functionality, as at
least on OMAP4 / OMAP5 / DRA7 the clockdomains can be collections of either
clocks and/or IP blocks, thus idle-domain or such might be more appropriate.
For most cases on these SoCs, the kernel doesn't even need the information
and the mappings can be ignored.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/ti/clockdomain.txt b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt
new file mode 100644
index 000000000000..cb76b3f2b341
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt
@@ -0,0 +1,24 @@
+Binding for Texas Instruments clockdomain.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1] in consumer role.
+Every clock on TI SoC belongs to one clockdomain, but software
+only needs this information for specific clocks which require
+their parent clockdomain to be controlled when the clock is
+enabled/disabled. This binding doesn't define a new clock
+binding type, it is used to group existing clock nodes under
+hardware hierarchy.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "ti,clockdomain"
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : link phandles of clocks within this domain
+
+Examples:
+        dss_clkdm: dss_clkdm {
+                compatible = "ti,clockdomain";
+                clocks = <&dss1_alwon_fck_3430es2>, <&dss_ick_3430es2>;
+        };