[U-Boot] [PATCH 1/3] fdt: add memory bank decoding functions for board setup

[Nathan Rossi]

Add two functions for use by board implementations to decode the memory
banks of the /memory node so as to populate the global data with
ram_size and board info for memory banks.

The fdtdec_setup_memory_size() function decodes the first memory bank
and sets up the gd->ram_size with the size of the memory bank. This
function should be called from the boards dram_init().

The fdtdec_setup_memory_banksize() function decode the memory banks
(up to the CONFIG_NR_DRAM_BANKS) and populates the base address and size
into the gd->bd->bi_dram array of banks. This function should be called
from the boards dram_init_banksize().

Signed-off-by: Nathan Rossi <nathan at nathanrossi.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Michal Simek <monstr at monstr.eu>
---
This implementation of decoding has been tested on zynq and zynqmp
boards with address/size cells of (1, 1), (1, 2), (2, 1), (2, 2) and
up to 2 memory banks.
---
 include/fdtdec.h | 25 +++++++++++++++++++++++++
 lib/fdtdec.c     | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/include/fdtdec.h b/include/fdtdec.h
index 27887c8c21..59a204b571 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -976,6 +976,31 @@ struct display_timing {
  */
 int fdtdec_decode_display_timing(const void *blob, int node, int index,
 				 struct display_timing *config);
+
+/**
+ * fdtdec_setup_memory_size() - decode and setup gd->ram_size
+ *
+ * Decode the /memory 'reg' property to determine the size of the first memory
+ * bank, populate the global data with the size of the first bank of memory.
+ * This function should be called from the boards dram_init().
+ *
+ * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
+ * invalid
+ */
+int fdtdec_setup_memory_size(void);
+
+/**
+ * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
+ *
+ * Decode the /memory 'reg' property to determine the address and size of the
+ * memory banks. Use this data to populate the global data board info with the
+ * phys address and size of memory banks. This function should be called from
+ * the boards dram_init_banksize().
+ *
+ * @return 0 if OK, negative on error
+ */
+int fdtdec_setup_memory_banksize(void);
+
 /**
  * Set up the device tree ready for use
  */
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 4e619c49a2..bc3be017b6 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1174,6 +1174,60 @@ int fdtdec_decode_display_timing(const void *blob, int parent, int index,
 	return ret;
 }
 
+int fdtdec_setup_memory_size(void)
+{
+	int ret, mem;
+	struct fdt_resource res;
+
+	mem = fdt_path_offset(gd->fdt_blob, "/memory");
+	if (mem < 0) {
+		debug("%s: Missing /memory node\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = fdt_get_resource(gd->fdt_blob, mem, "reg", 0, &res);
+	if (ret != 0) {
+		debug("%s: Unable to decode first memory bank\n", __func__);
+		return -EINVAL;
+	}
+
+	gd->ram_size = (phys_size_t)(res.end - res.start + 1);
+	debug("%s: Initial DRAM size %llx\n", __func__, (u64)gd->ram_size);
+
+	return 0;
+}
+
+int fdtdec_setup_memory_banksize(void)
+{
+	int bank, ret, mem;
+	struct fdt_resource res;
+
+	mem = fdt_path_offset(gd->fdt_blob, "/memory");
+	if (mem < 0) {
+		debug("%s: Missing /memory node\n", __func__);
+		return -EINVAL;
+	}
+
+	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
+		ret = fdt_get_resource(gd->fdt_blob, mem, "reg", bank, &res);
+		if (ret == -FDT_ERR_NOTFOUND)
+			break;
+		if (ret != 0)
+			return ret;
+
+		gd->bd->bi_dram[bank].start = (phys_addr_t)res.start;
+		gd->bd->bi_dram[bank].size =
+			(phys_size_t)(res.end - res.start + 1);
+
+		debug("%s: DRAM Bank #%d: start = 0x%llx, size = 0x%llx\n",
+		      __func__, bank,
+		      (unsigned long long)gd->bd->bi_dram[bank].start,
+		      (unsigned long long)gd->bd->bi_dram[bank].size);
+	}
+
+	return 0;
+}
+
 int fdtdec_setup(void)
 {
 #if CONFIG_IS_ENABLED(OF_CONTROL)
-- 
2.10.2