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authorSimon Glass <sjg@chromium.org>2014-10-23 18:58:56 -0600
committerSimon Glass <sjg@chromium.org>2014-11-21 04:43:18 +0100
commit2640387148ad5e0197a8ac80c24f3473dee42a65 (patch)
treebb174337344044010875651980e4562dacad08a1
parent41f09bbe594aac18fea208423494729d52b85eee (diff)
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fdt: Add a function to decode a named memory region
Permit decoding of a named memory region from the device tree. This allows easy run-time configuration of the address of on-chip SRAM, SDRAM, etc. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@ti.com>
-rw-r--r--include/fdtdec.h27
-rw-r--r--lib/fdtdec.c61
2 files changed, 88 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 1a931e8..a7655dc 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -677,4 +677,31 @@ int fdt_get_named_resource(const void *fdt, int node, const char *property,
*/
int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
+/**
+ * Decode a named region within a memory bank of a given type.
+ *
+ * This function handles selection of a memory region. The region is
+ * specified as an offset/size within a particular type of memory.
+ *
+ * The properties used are:
+ *
+ * <mem_type>-memory<suffix> for the name of the memory bank
+ * <mem_type>-offset<suffix> for the offset in that bank
+ *
+ * The property value must have an offset and a size. The function checks
+ * that the region is entirely within the memory bank.5
+ *
+ * @param blob FDT blob
+ * @param node Node containing the properties (-1 for /config)
+ * @param mem_type Type of memory to use, which is a name, such as
+ * "u-boot" or "kernel".
+ * @param suffix String to append to the memory/offset
+ * property names
+ * @param basep Returns base of region
+ * @param sizep Returns size of region
+ * @return 0 if OK, -ive on error
+ */
+int fdtdec_decode_memory_region(const void *blob, int node,
+ const char *mem_type, const char *suffix,
+ fdt_addr_t *basep, fdt_size_t *sizep);
#endif
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 4dbd6ae..9c332ad 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -793,4 +793,65 @@ int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf)
return 0;
}
+
+int fdtdec_decode_memory_region(const void *blob, int config_node,
+ const char *mem_type, const char *suffix,
+ fdt_addr_t *basep, fdt_size_t *sizep)
+{
+ char prop_name[50];
+ const char *mem;
+ fdt_size_t size, offset_size;
+ fdt_addr_t base, offset;
+ int node;
+
+ if (config_node == -1) {
+ config_node = fdt_path_offset(blob, "/config");
+ if (config_node < 0) {
+ debug("%s: Cannot find /config node\n", __func__);
+ return -ENOENT;
+ }
+ }
+ if (!suffix)
+ suffix = "";
+
+ snprintf(prop_name, sizeof(prop_name), "%s-memory%s", mem_type,
+ suffix);
+ mem = fdt_getprop(blob, config_node, prop_name, NULL);
+ if (!mem) {
+ debug("%s: No memory type for '%s', using /memory\n", __func__,
+ prop_name);
+ mem = "/memory";
+ }
+
+ node = fdt_path_offset(blob, mem);
+ if (node < 0) {
+ debug("%s: Failed to find node '%s': %s\n", __func__, mem,
+ fdt_strerror(node));
+ return -ENOENT;
+ }
+
+ /*
+ * Not strictly correct - the memory may have multiple banks. We just
+ * use the first
+ */
+ if (fdtdec_decode_region(blob, node, "reg", &base, &size)) {
+ debug("%s: Failed to decode memory region %s\n", __func__,
+ mem);
+ return -EINVAL;
+ }
+
+ snprintf(prop_name, sizeof(prop_name), "%s-offset%s", mem_type,
+ suffix);
+ if (fdtdec_decode_region(blob, config_node, prop_name, &offset,
+ &offset_size)) {
+ debug("%s: Failed to decode memory region '%s'\n", __func__,
+ prop_name);
+ return -EINVAL;
+ }
+
+ *basep = base + offset;
+ *sizep = offset_size;
+
+ return 0;
+}
#endif