pitx-imx8m: enable 4GB support

- setup DRAM1 and DRAM2 memory region size correctly
- add functionality to populate bi_dram[].start and
  bi_dram[].size struct variables appropriately.
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

board/kontron/pitx-imx8m/pitx-imx8m.c

@@ -93,13 +93,35 @@ int board_postclk_init(void)
 }
 #endif
 
-int dram_init(void)
+phys_size_t get_effective_memsize(void)
 {
 	/* rom_pointer[1] contains the size of TEE occupies */
 	if (rom_pointer[1])
-		gd->ram_size = PHYS_SDRAM_SIZE - rom_pointer[1];
+		return (PHYS_SDRAM_SIZE - rom_pointer[1]);
 	else
-		gd->ram_size = PHYS_SDRAM_SIZE;
+		return PHYS_SDRAM_SIZE;
+}
+
+int dram_init(void)
+{
+	gd->ram_size = get_effective_memsize();
+
+#if CONFIG_NR_DRAM_BANKS > 1
+	gd->ram_size += PHYS_SDRAM_2_SIZE;
+#endif
+
+	return 0;
+}
+
+int dram_init_banksize(void)
+{
+	gd->bd->bi_dram[0].start = PHYS_SDRAM;
+	gd->bd->bi_dram[0].size = get_effective_memsize();
+
+#if CONFIG_NR_DRAM_BANKS > 1
+	gd->bd->bi_dram[1].start = PHYS_SDRAM_2;
+	gd->bd->bi_dram[1].size = PHYS_SDRAM_2_SIZE;
+#endif
 
 	return 0;
 }

include/configs/pitx-imx8m.h

@@ -225,9 +225,10 @@
 /* Size of malloc() pool */
 #define CONFIG_SYS_MALLOC_LEN		((CONFIG_ENV_SIZE + (2*1024) + (16*1024)) * 1024)
 
-#define CONFIG_SYS_SDRAM_BASE           0x40000000
 #define PHYS_SDRAM                      0x40000000
-#define PHYS_SDRAM_SIZE			0xC0000000 /* 3GB DDR */
+#define PHYS_SDRAM_SIZE			0xC0000000 /* 3GB DDR in DRAM1 region */
+#define PHYS_SDRAM_2			0x100000000UL
+#define PHYS_SDRAM_2_SIZE		0x40000000 /* 1GB DDR in DRAM2 region */
 
 #define CONFIG_SYS_MEMTEST_START    PHYS_SDRAM
 #define CONFIG_SYS_MEMTEST_END      (CONFIG_SYS_MEMTEST_START + (PHYS_SDRAM_SIZE >> 1))