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--- zephyr:device_drivers [2025/07/08 10:42] – [DT Macros] utedass
+++ zephyr:device_drivers [2025/07/08 19:08] (current) – utedass
@@ Line 68: / Line 68: @@
 So the instance nubmer is an index of all nodes with a particular compatible. Node identifier, I assume, is an index over ALL device tree nodes. So like a local vs global index.
+By checking the build folder and the generated include files, one can observe that
+<code c>
+// An instance number is a number 0 through n
+// But the node identifier will be something along the lines of DT_N_S_soc_S_i2c_40005400_S_si5351_60
+// The macro DT_INST(0, skyworks_si5351) would retrieve this define from the generated source
+#define DT_N_INST_0_skyworks_si5351 DT_N_S_soc_S_i2c_40005400_S_si5351_60
+// The DT_DRV_COMPAT that you define to something along the lines skyworks_si5351 will be just that, a token. Not anything magical.
+// But it will be used by the zephyr provided helper macros to construct the names for the defines generated by the build system to the devicetree_generated.h so that you can retrieve them
+// For example, the macro used to retrieve a property
+DT_INST_PROP(inst, plla_p1)
+// would expand to DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_plla_p1
+// According to the generated header:
+/*
+ * Devicetree node: /soc/i2c@40005400/si5351@60
+ *
+ * Node identifier: DT_N_S_soc_S_i2c_40005400_S_si5351_60
+ *
+ * Binding (compatible = skyworks,si5351):
+ *   /workspace/modules/si5351/dts/bindings/clock/skyworks,si5351.yaml
+ *
+ * (Descriptions have moved to the Devicetree Bindings Index
+ * in the documentation.)
+ */
+// Some of the generated properties looks like this
+/* Generic property macros: */
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_clkin_div 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_clkin_div_IDX_0_ENUM_IDX 0
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_clkin_div_IDX_0_EXISTS 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_clkin_div_IDX_0_ENUM_VAL_1_EXISTS 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_clkin_div_EXISTS 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_plla_p1 1638
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_plla_p1_EXISTS 1
+// For things like string enum there are a whole bunch of lines generated
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source "XTAL"
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_STRING_UNQUOTED XTAL
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_STRING_TOKEN XTAL
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_STRING_UPPER_TOKEN XTAL
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_IDX_0 "XTAL"
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_IDX_0_EXISTS 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_IDX_0_ENUM_IDX 0
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_IDX_0_ENUM_VAL_XTAL_EXISTS 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_FOREACH_PROP_ELEM(fn) fn(DT_N_S_soc_S_i2c_40005400_S_si5351_60, pllb_clock_source, 0)
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_FOREACH_PROP_ELEM_SEP(fn, sep) fn(DT_N_S_soc_S_i2c_40005400_S_si5351_60, pllb_clock_source, 0)
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_FOREACH_PROP_ELEM_VARGS(fn, ...) fn(DT_N_S_soc_S_i2c_40005400_S_si5351_60, pllb_clock_source, 0, __VA_ARGS__)
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_FOREACH_PROP_ELEM_SEP_VARGS(fn, sep, ...) fn(DT_N_S_soc_S_i2c_40005400_S_si5351_60, pllb_clock_source, 0, __VA_ARGS__)
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_LEN 1
+#define DT_N_S_soc_S_i2c_40005400_S_si5351_60_P_pllb_clock_source_EXISTS 1
+</code>