dts: bindings: adc: add properties for stm32 adc clock source

Add two properties to define the STM32 ADC clock source:
- Clock source: synchronous or asynchronous
- Clock prescaler
By combining these two parameters, it will be possible to set the desired
ADC clock for most series.

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>

dts/bindings/adc/st,stm32-adc.yaml

@@ -27,6 +27,44 @@ properties:
   pinctrl-names:
     required: true
 
+  st,adc-clock-source:
+    type: int
+    required: true
+    enum:
+      - 1 # SYNC for synchronous ADC clock source
+      - 2 # ASYNC for asynchronous ADC clock source
+    description: |
+      Type of ADC clock source :
+      - <SYNC>: derived from the bus clock.
+      - <ASYNC> : independent and asynchronous with the bus clock
+      One of the two values may not apply to some series. Refer to the RefMan.
+
+  st,adc-prescaler:
+    type: int
+    required: true
+    enum:
+      - 1 # not divided
+      - 2
+      - 4
+      - 6
+      - 8
+      - 10
+      - 12
+      - 16
+      - 32
+      - 64
+      - 128
+      - 256
+    description: |
+      Clock prescaler at the input of the ADC:
+      Apply to synchronous or asynchronous clock depending on the STM32
+      st,adc-clock-source.
+      Some of the values may not apply to some series, and may depend on the
+      selected clock source. Refer to the RefMan.
+      On STM32F3x (except STM32F37x), this configures only the synchronous
+      prescaler (see properties adcXX-prescaler in st,stm32f3-rcc bindings to
+      set asynchronous prescaler).
+
   vref-mv:
     type: int
     default: 3300

dts/bindings/adc/st,stm32f1-adc.yaml

@@ -5,8 +5,15 @@
 description: |
         ST STM32F1 family ADC
         This compatible stands for all ADC blocks similar to the one on STM32F1,
-        like F37x.
+        like STM32F37x.
+        Remove the st,adc-clock-source and st,adc-prescaler property.
+        See adc-prescaler property in st,stm32f1-rcc binding to configure ADC
+        prescaler.
 
 compatible: "st,stm32f1-adc"
 
-include: st,stm32-adc.yaml
+include:
+  - name: st,stm32-adc.yaml
+    property-blocklist:
+      - st,adc-clock-source
+      - st,adc-prescaler