dt-bindings: clock: u8500: Add clkout clock bindings

This adds device tree bindings for the externally routed clocks
CLKOUT1 and CLKOUT2 clocks found in the DB8500.

Cc: [e-mail]
Reviewed-by: Ulf Hansson <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

Documentation/devicetree/bindings/clock/stericsson,u8500-clks.yaml

···
 
     additionalProperties: false
 
+  clkout-clock:
+    description: A subnode with three clock cells for externally routed clocks,
+      output clocks. These are two PRCMU-internal clocks that can be divided and
+      muxed out on the pads of the DB8500 SoC.
+    type: object
+
+    properties:
+      '#clock-cells':
+        description:
+          The first cell indicates which output clock we are using,
+          possible values are 0 (CLKOUT1) and 1 (CLKOUT2).
+          The second cell indicates which clock we want to use as source,
+          possible values are 0 thru 7, see the defines for the different
+          source clocks.
+          The third cell is a divider, legal values are 1 thru 63.
+        const: 3
+
+    additionalProperties: false
+
 required:
   - compatible
   - reg
···
   - smp-twd-clock
 
 additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/ste-db8500-clkout.h>
+    clocks@8012 {
+      compatible = "stericsson,u8500-clks";
+      reg = <0x8012f000 0x1000>, <0x8011f000 0x1000>,
+            <0x8000f000 0x1000>, <0xa03ff000 0x1000>,
+            <0xa03cf000 0x1000>;
+
+      prcmu_clk: prcmu-clock {
+        #clock-cells = <1>;
+      };
+
+      prcc_pclk: prcc-periph-clock {
+        #clock-cells = <2>;
+      };
+
+      prcc_kclk: prcc-kernel-clock {
+        #clock-cells = <2>;
+      };
+
+      prcc_reset: prcc-reset-controller {
+        #reset-cells = <2>;
+      };
+
+      rtc_clk: rtc32k-clock {
+        #clock-cells = <0>;
+      };
+
+      smp_twd_clk: smp-twd-clock {
+        #clock-cells = <0>;
+      };
+
+      clkout_clk: clkout-clock {
+        #clock-cells = <3>;
+      };
+    };

include/dt-bindings/clock/ste-db8500-clkout.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __STE_CLK_DB8500_CLKOUT_H__
+#define __STE_CLK_DB8500_CLKOUT_H__
+
+#define DB8500_CLKOUT_1			0
+#define DB8500_CLKOUT_2			1
+
+#define DB8500_CLKOUT_SRC_CLK38M	0
+#define DB8500_CLKOUT_SRC_ACLK		1
+#define DB8500_CLKOUT_SRC_SYSCLK	2
+#define DB8500_CLKOUT_SRC_LCDCLK	3
+#define DB8500_CLKOUT_SRC_SDMMCCLK	4
+#define DB8500_CLKOUT_SRC_TVCLK		5
+#define DB8500_CLKOUT_SRC_TIMCLK	6
+#define DB8500_CLKOUT_SRC_CLK009	7
+
+#endif