[PATCH v4 1/3] ARM: shmobile: r8a7791: add CAN clocks

[Sergei Shtylyov]

The R-Car CAN controllers can derive the CAN bus clock not only from their
peripheral clock input (clkp1) but also from the other internal clock (clkp2)
and external clock fed on CAN_CLK pin.  Describe those clocks in the device
tree,  along with  the USB_EXTAL clock  from which clkp2 is derived.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov at cogentembedded.com>

---
Changes in version 4:
- refreshed the patch.

Changes in version 3:
- new patch.

 arch/arm/boot/dts/r8a7791.dtsi            |   23 +++++++++++++++++++++--
 include/dt-bindings/clock/r8a7791-clock.h |    1 +
 2 files changed, 22 insertions(+), 2 deletions(-)

Index: renesas/arch/arm/boot/dts/r8a7791.dtsi
===================================================================
--- renesas.orig/arch/arm/boot/dts/r8a7791.dtsi
+++ renesas/arch/arm/boot/dts/r8a7791.dtsi
@@ -862,15 +862,34 @@
 			status = "disabled";
 		};
 
+		/* External USB clock - can be overridden by the board */
+		usb_extal_clk: usb_extal_clk {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <48000000>;
+			clock-output-names = "usb_extal";
+		};
+
+		/* External CAN clock */
+		can_clk: can_clk {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			/* This value must be overriden by the board. */
+			clock-frequency = <0>;
+			clock-output-names = "can_clk";
+			status = "disabled";
+		};
+
 		/* Special CPG clocks */
 		cpg_clocks: cpg_clocks at e6150000 {
 			compatible = "renesas,r8a7791-cpg-clocks",
 				     "renesas,rcar-gen2-cpg-clocks";
 			reg = <0 0xe6150000 0 0x1000>;
-			clocks = <&extal_clk>;
+			clocks = <&extal_clk &usb_extal_clk>;
 			#clock-cells = <1>;
 			clock-output-names = "main", "pll0", "pll1", "pll3",
-					     "lb", "qspi", "sdh", "sd0", "z";
+					     "lb", "qspi", "sdh", "sd0", "z",
+					     "rcan";
 		};
 
 		/* Variable factor clocks */
Index: renesas/include/dt-bindings/clock/r8a7791-clock.h
===================================================================
--- renesas.orig/include/dt-bindings/clock/r8a7791-clock.h
+++ renesas/include/dt-bindings/clock/r8a7791-clock.h
@@ -20,6 +20,7 @@
 #define R8A7791_CLK_SDH			6
 #define R8A7791_CLK_SD0			7
 #define R8A7791_CLK_Z			8
+#define R8A7791_CLK_RCAN		9
 
 /* MSTP0 */
 #define R8A7791_CLK_MSIOF0		0