CLK: TI: DRA7: Add APLL support

The patch adds support for DRA7 PCIe APLL. The APLL
sources the optional functional clocks for PCIe module.

APLL stands for Analog PLL. This is different when comapred
with DPLL meaning Digital PLL, the phase detection is done
using an analog circuit.

Signed-off-by: J Keerthy <j-keerthy@ti.com>
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, 31 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/ti/apll.txt b/Documentation/devicetree/bindings/clock/ti/apll.txt
new file mode 100644
index 000000000000..7faf5a68b3be
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/apll.txt
@@ -0,0 +1,31 @@
+Binding for Texas Instruments APLL clock.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1].  It assumes a
+register-mapped APLL with usually two selectable input clocks
+(reference clock and bypass clock), with analog phase locked
+loop logic for multiplying the input clock to a desired output
+clock. This clock also typically supports different operation
+modes (locked, low power stop etc.) APLL mostly behaves like
+a subtype of a DPLL [2], although a simplified one at that.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/ti/dpll.txt
+
+Required properties:
+- compatible : shall be "ti,dra7-apll-clock"
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : link phandles of parent clocks (clk-ref and clk-bypass)
+- reg : address and length of the register set for controlling the APLL.
+  It contains the information of registers in the following order:
+	"control" - contains the control register base address
+	"idlest" - contains the idlest register base address
+
+Examples:
+	apll_pcie_ck: apll_pcie_ck@4a008200 {
+		#clock-cells = <0>;
+		clocks = <&apll_pcie_in_clk_mux>, <&dpll_pcie_ref_ck>;
+		reg = <0x4a00821c 0x4>, <0x4a008220 0x4>;
+		compatible = "ti,dra7-apll-clock";
+	};