From: Elaine Zhang <zhangqing@rock-chips.com>
Date: Fri, 2 Jun 2017 01:47:24 +0000 (+0800)
Subject: UPSTREAM: dt-bindings: add bindings for rk3128 clock controller
X-Git-Tag: release-20171130_firefly~4^2~460
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9dd71cf53a34afbb91e3e0905324427b175cee42;p=firefly-linux-kernel-4.4.55.git

UPSTREAM: dt-bindings: add bindings for rk3128 clock controller

Add devicetree bindings for Rockchip cru which found on
Rockchip SoCs.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
(cherry picked from git.kernel.org mmind/linux-rockchip.git v4.13-clk/next
 commit de2ddc3b694d4594d922534db19e15fc39a3fcee)

Change-Id: I7ee66379d024020a9f8bcc98c3d9c4341391cccd
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
---

diff --git a/Documentation/devicetree/bindings/clock/rockchip,rk3128-cru.txt b/Documentation/devicetree/bindings/clock/rockchip,rk3128-cru.txt
new file mode 100644
index 000000000000..455a9a00a623
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/rockchip,rk3128-cru.txt
@@ -0,0 +1,56 @@
+* Rockchip RK3128 Clock and Reset Unit
+
+The RK3128 clock controller generates and supplies clock to various
+controllers within the SoC and also implements a reset controller for SoC
+peripherals.
+
+Required Properties:
+
+- compatible: should be "rockchip,rk3128-cru"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- #clock-cells: should be 1.
+- #reset-cells: should be 1.
+
+Optional Properties:
+
+- rockchip,grf: phandle to the syscon managing the "general register files"
+  If missing pll rates are not changeable, due to the missing pll lock status.
+
+Each clock is assigned an identifier and client nodes can use this identifier
+to specify the clock which they consume. All available clocks are defined as
+preprocessor macros in the dt-bindings/clock/rk3128-cru.h headers and can be
+used in device tree sources. Similar macros exist for the reset sources in
+these files.
+
+External clocks:
+
+There are several clocks that are generated outside the SoC. It is expected
+that they are defined using standard clock bindings with following
+clock-output-names:
+ - "xin24m" - crystal input - required,
+ - "ext_i2s" - external I2S clock - optional,
+ - "gmac_clkin" - external GMAC clock - optional
+
+Example: Clock controller node:
+
+	cru: cru@20000000 {
+		compatible = "rockchip,rk3128-cru";
+		reg = <0x20000000 0x1000>;
+		rockchip,grf = <&grf>;
+
+		#clock-cells = <1>;
+		#reset-cells = <1>;
+	};
+
+Example: UART controller node that consumes the clock generated by the clock
+  controller:
+
+	uart2: serial@20068000 {
+		compatible = "rockchip,serial";
+		reg = <0x20068000 0x100>;
+		interrupts = <GIC_SPI 22 IRQ_TYPE_LEVEL_HIGH>;
+		clock-frequency = <24000000>;
+		clocks = <&cru SCLK_UART2>, <&cru PCLK_UART2>;
+		clock-names = "sclk_uart", "pclk_uart";
+	};