dts/bindings: Add binding for STM32WL HSE Clock

STM32WL features a specific HSE clock with dedicated properties.
Add a dedicated binding and update STM32 clock control driver
header to take it into account.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

dts/bindings/clock/st,stm32wl-hse-clock.yaml

@@ -0,0 +1,23 @@
+# Copyright (c) 2021, Linaro ltd
+# SPDX-License-Identifier: Apache-2.0
+
+description: STM32WL HSE Clock
+
+compatible: "st,stm32wl-hse-clock"
+
+include: [fixed-clock.yaml]
+
+properties:
+    hse-tcxo:
+      type: boolean
+      required: false
+      description: |
+        When set, TCXO is selected as external source clock for HSE.
+        Otherwise, external cyrstal is selected as HSE source clock.
+
+    hse-div2:
+      type: boolean
+      required: false
+      description: |
+        When set HSE output clock is divided by 2.
+        Otherwise, no prescaler is used.

include/drivers/clock_control/stm32_clock_control.h

@@ -309,10 +309,15 @@
 
 #if DT_NODE_HAS_COMPAT_STATUS(DT_NODELABEL(clk_hse), st_stm32_hse_clock, okay)
 #define STM32_HSE_BYPASS	DT_PROP(DT_NODELABEL(clk_hse), hse_bypass)
-#else
+#elif !DT_NODE_HAS_COMPAT_STATUS(DT_NODELABEL(clk_hse), st_stm32wl_hse_clock, okay)
 #define STM32_HSE_BYPASS	CONFIG_CLOCK_STM32_HSE_BYPASS
 #endif
 
+#if DT_NODE_HAS_COMPAT_STATUS(DT_NODELABEL(clk_hse), st_stm32wl_hse_clock, okay)
+#define STM32_HSE_TCXO	DT_PROP(DT_NODELABEL(clk_hse), hse_tcxo)
+#define STM32_HSE_DIV2	DT_PROP(DT_NODELABEL(clk_hse), hse_div2)
+#endif
+
 struct stm32_pclken {
 	uint32_t bus;
 	uint32_t enr;