M28: Add memory detection into SPL

This code allows the DDR DRAM size to be detected at runtime. The RAM size is
stored into two scratch registers, from which it is then fetched in U-Boot.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>

1 files changed, 16 insertions, 2 deletions

diff --git a/board/denx/m28evk/m28evk.c b/board/denx/m28evk/m28evk.c
index 118e2222a5..168ceeb6a5 100644
--- a/board/denx/m28evk/m28evk.c
+++ b/board/denx/m28evk/m28evk.c
@@ -63,10 +63,24 @@ int board_init(void)
 	return 0;
 }
 
+#define	HW_DIGCTRL_SCRATCH0	0x8001c280
+#define	HW_DIGCTRL_SCRATCH1	0x8001c290
 int dram_init(void)
 {
-	/* dram_init must store complete ramsize in gd->ram_size */
-	gd->ram_size = get_ram_size((long *)PHYS_SDRAM_1, PHYS_SDRAM_1_SIZE);
+	uint32_t sz[2];
+
+	sz[0] = readl(HW_DIGCTRL_SCRATCH0);
+	sz[1] = readl(HW_DIGCTRL_SCRATCH1);
+
+	if (sz[0] != sz[1]) {
+		printf("MX28:\n"
+			"Error, the RAM size in HW_DIGCTRL_SCRATCH0 and\n"
+			"HW_DIGCTRL_SCRATCH1 is not the same. Please\n"
+			"verify these two registers contain valid RAM size!\n");
+		hang();
+	}
+
+	gd->ram_size = sz[0];
 	return 0;
 }