stm32mp: add DT helper for reg by name

Add a new entry to find register properties by name and
include new assert functions to limit address cells to 1
and size cells to 1.

Change-Id: Ide59a795a05fb2af36bd07fec15e5a3adf196226
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>

plat/st/common/include/stm32mp_dt.h

@@ -32,6 +32,8 @@ uint32_t fdt_read_uint32_default(int node, const char *prop_name,
 				 uint32_t dflt_value);
 int fdt_read_uint32_array(int node, const char *prop_name,
 			  uint32_t *array, uint32_t count);
+int fdt_get_reg_props_by_name(int node, const char *name, uintptr_t *base,
+			      size_t *size);
 int dt_set_stdout_pinctrl(void);
 void dt_fill_device_info(struct dt_node_info *info, int node);
 int dt_get_node(struct dt_node_info *info, int offset, const char *compat);

plat/st/common/stm32mp_dt.c

@@ -92,6 +92,46 @@ uint8_t fdt_get_status(int node)
 	return status;
 }
 
+/*******************************************************************************
+ * This function returns the address cells from the node parent.
+ * Returns:
+ * - #address-cells value if success.
+ * - invalid value if error.
+ * - a default value if undefined #address-cells property as per libfdt
+ *   implementation.
+ ******************************************************************************/
+int fdt_get_node_parent_address_cells(int node)
+{
+	int parent;
+
+	parent = fdt_parent_offset(fdt, node);
+	if (parent < 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	return fdt_address_cells(fdt, parent);
+}
+
+/*******************************************************************************
+ * This function returns the size cells from the node parent.
+ * Returns:
+ * - #size-cells value if success.
+ * - invalid value if error.
+ * - a default value if undefined #size-cells property as per libfdt
+ *   implementation.
+ ******************************************************************************/
+int fdt_get_node_parent_size_cells(int node)
+{
+	int parent;
+
+	parent = fdt_parent_offset(fdt, node);
+	if (parent < 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	return fdt_size_cells(fdt, parent);
+}
+
 /*******************************************************************************
  * This function reads a value of a node property (generic use of fdt
  * library).
@@ -145,6 +185,46 @@ int fdt_read_uint32_array(int node, const char *prop_name, uint32_t *array,
 	return 0;
 }
 
+/*******************************************************************************
+ * This function fills reg node info (base & size) with an index found by
+ * checking the reg-names node.
+ * Returns 0 on success and a negative FDT error code on failure.
+ ******************************************************************************/
+int fdt_get_reg_props_by_name(int node, const char *name, uintptr_t *base,
+			      size_t *size)
+{
+	const fdt32_t *cuint;
+	int index, len;
+
+	assert((fdt_get_node_parent_address_cells(node) == 1) &&
+	       (fdt_get_node_parent_size_cells(node) == 1));
+
+	index = fdt_stringlist_search(fdt, node, "reg-names", name);
+	if (index < 0) {
+		return index;
+	}
+
+	cuint = fdt_getprop(fdt, node, "reg", &len);
+	if (cuint == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	if ((index * (int)sizeof(uint32_t)) > len) {
+		return -FDT_ERR_BADVALUE;
+	}
+
+	cuint += index << 1;
+	if (base != NULL) {
+		*base = fdt32_to_cpu(*cuint);
+	}
+	cuint++;
+	if (size != NULL) {
+		*size = fdt32_to_cpu(*cuint);
+	}
+
+	return 0;
+}
+
 /*******************************************************************************
  * This function gets the stdout path node.
  * It reads the value indicated inside the device tree.
@@ -215,6 +295,8 @@ void dt_fill_device_info(struct dt_node_info *info, int node)
 {
 	const fdt32_t *cuint;
 
+	assert(fdt_get_node_parent_address_cells(node) == 1);
+
 	cuint = fdt_getprop(fdt, node, "reg", NULL);
 	if (cuint != NULL) {
 		info->base = fdt32_to_cpu(*cuint);
@@ -309,6 +391,9 @@ uintptr_t dt_get_ddrctrl_base(void)
 		return 0;
 	}
 
+	assert((fdt_get_node_parent_address_cells(node) == 1) &&
+	       (fdt_get_node_parent_size_cells(node) == 1));
+
 	if (fdt_read_uint32_array(node, "reg", array, 4) < 0) {
 		return 0;
 	}
@@ -331,6 +416,9 @@ uintptr_t dt_get_ddrphyc_base(void)
 		return 0;
 	}
 
+	assert((fdt_get_node_parent_address_cells(node) == 1) &&
+	       (fdt_get_node_parent_size_cells(node) == 1));
+
 	if (fdt_read_uint32_array(node, "reg", array, 4) < 0) {
 		return 0;
 	}
@@ -353,6 +441,8 @@ uintptr_t dt_get_pwr_base(void)
 		return 0;
 	}
 
+	assert(fdt_get_node_parent_address_cells(node) == 1);
+
 	cuint = fdt_getprop(fdt, node, "reg", NULL);
 	if (cuint == NULL) {
 		return 0;
@@ -415,6 +505,8 @@ uintptr_t dt_get_syscfg_base(void)
 		return 0;
 	}
 
+	assert(fdt_get_node_parent_address_cells(node) == 1);
+
 	cuint = fdt_getprop(fdt, node, "reg", NULL);
 	if (cuint == NULL) {
 		return 0;