clk: at91: add slow clk documentation
Add slow clk, and slow oscillators documentation.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 26d2c84..27f9a27 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -6,6 +6,16 @@
Required properties:
- compatible : shall be one of the following:
+ "atmel,at91sam9x5-sckc":
+ at91 SCKC (Slow Clock Controller)
+ This node contains the slow clock definitions.
+
+ "atmel,at91sam9x5-clk-slow-osc":
+ at91 slow oscillator
+
+ "atmel,at91sam9x5-clk-slow-rc-osc":
+ at91 internal slow RC oscillator
+
"atmel,at91rm9200-pmc" or
"atmel,at91sam9g45-pmc" or
"atmel,at91sam9n12-pmc" or
@@ -15,6 +25,11 @@
All at91 specific clocks (clocks defined below) must be child
node of the PMC node.
+ "atmel,at91sam9x5-clk-slow" (under sckc node)
+ or
+ "atmel,at91sam9260-clk-slow" (under pmc node):
+ at91 slow clk
+
"atmel,at91rm9200-clk-main-osc"
"atmel,at91sam9x5-clk-main-rc-osc"
at91 main clk sources
@@ -59,6 +74,63 @@
"atmel,at91sam9x5-clk-utmi":
at91 utmi clock
+Required properties for SCKC node:
+- reg : defines the IO memory reserved for the SCKC.
+- #size-cells : shall be 0 (reg is used to encode clk id).
+- #address-cells : shall be 1 (reg is used to encode clk id).
+
+
+For example:
+ sckc: sckc@fffffe50 {
+ compatible = "atmel,sama5d3-pmc";
+ reg = <0xfffffe50 0x4>
+ #size-cells = <0>;
+ #address-cells = <1>;
+
+ /* put at91 slow clocks here */
+ };
+
+
+Required properties for internal slow RC oscillator:
+- #clock-cells : from common clock binding; shall be set to 0.
+- clock-frequency : define the internal RC oscillator frequency.
+
+Optional properties:
+- clock-accuracy : define the internal RC oscillator accuracy.
+
+For example:
+ slow_rc_osc: slow_rc_osc {
+ compatible = "atmel,at91sam9x5-clk-slow-rc-osc";
+ clock-frequency = <32768>;
+ clock-accuracy = <50000000>;
+ };
+
+Required properties for slow oscillator:
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : shall encode the main osc source clk sources (see atmel datasheet).
+
+Optional properties:
+- atmel,osc-bypass : boolean property. Set this when a clock signal is directly
+ provided on XIN.
+
+For example:
+ slow_osc: slow_osc {
+ compatible = "atmel,at91rm9200-clk-slow-osc";
+ #clock-cells = <0>;
+ clocks = <&slow_xtal>;
+ };
+
+Required properties for slow clock:
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : shall encode the slow clk sources (see atmel datasheet).
+
+For example:
+ clk32k: slck {
+ compatible = "atmel,at91sam9x5-clk-slow";
+ #clock-cells = <0>;
+ clocks = <&slow_rc_osc &slow_osc>;
+ };
+
Required properties for PMC node:
- reg : defines the IO memory reserved for the PMC.
- #size-cells : shall be 0 (reg is used to encode clk id).