[U-Boot] [PATCH 1/3] tegra: add a method to query RAM size from hardware

[Lucas Stach]

The RAM configuration is set by the bootrom to values specified by the BCT.
To query the available RAM size of a board we can easily read back those
values instead of using the hardcoded ODMdata. This allows for a single
u-boot image on similar boards with different amount of RAM.

Note that the register description in the TRM is not entirely correct here.

Signed-off-by: Lucas Stach <dev at lynxeye.de>
CC: Stephen Warren <swarren at wwwdotorg.org>
CC: Tom Warren <twarren.nvidia at gmail.com>
CC: Marek Vasut <marex at denx.de>
---
 arch/arm/cpu/armv7/tegra2/board.c         |   21 ++++++++++++++++++++-
 arch/arm/include/asm/arch-tegra2/tegra2.h |    1 +
 2 Dateien geändert, 21 Zeilen hinzugefügt(+), 1 Zeile entfernt(-)

diff --git a/arch/arm/cpu/armv7/tegra2/board.c b/arch/arm/cpu/armv7/tegra2/board.c
index 923678d..850a517 100644
--- a/arch/arm/cpu/armv7/tegra2/board.c
+++ b/arch/arm/cpu/armv7/tegra2/board.c
@@ -23,12 +23,14 @@
 
 #include <common.h>
 #include <asm/io.h>
-#include <asm/arch/ap20.h>
+#include <asm/sizes.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/funcmux.h>
 #include <asm/arch/pmc.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/tegra2.h>
+#include <asm/arch/pmc.h>
+#include <asm/arch/emc.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -47,6 +49,22 @@ enum {
 
 unsigned int query_sdram_size(void)
 {
+#ifdef CONFIG_TEGRA_RAMSIZE_BCT
+	/* get the memory size from the BCT programmed EMC register */
+	struct emc_ctlr *const emc = (struct emc_ctlr *)TEGRA2_EMC_BASE;
+	u32 cfg, cfg1 = 0, sz1 = 0, sz2 = 0;
+
+	cfg = readl(&emc->adr_cfg);
+	sz1 = SZ_4M << ((cfg & (0xf << 16)) >> 16);
+
+	/* if EMEM_NUMDEV is N2 we have to also read info for the second device */
+	if (cfg & (0x1 << 25)) {
+		cfg1 = readl(&emc->adr_cfg1);
+		sz2 = SZ_4M << ((cfg1 & (0xf << 16)) >> 16);
+	}
+
+	return sz1 + sz2;
+#else
 	struct pmc_ctlr *const pmc = (struct pmc_ctlr *)TEGRA2_PMC_BASE;
 	u32 reg;
 
@@ -63,6 +81,7 @@ unsigned int query_sdram_size(void)
 	case 3:
 		return 0x40000000;	/* 1GB */
 	}
+#endif
 }
 
 int dram_init(void)
diff --git a/arch/arm/include/asm/arch-tegra2/tegra2.h b/arch/arm/include/asm/arch-tegra2/tegra2.h
index d4ada10..8b57b77 100644
--- a/arch/arm/include/asm/arch-tegra2/tegra2.h
+++ b/arch/arm/include/asm/arch-tegra2/tegra2.h
@@ -41,6 +41,7 @@
 #define NV_PA_APB_UARTE_BASE	(NV_PA_APB_MISC_BASE + 0x6400)
 #define TEGRA2_SPI_BASE		(NV_PA_APB_MISC_BASE + 0xC380)
 #define TEGRA2_PMC_BASE		(NV_PA_APB_MISC_BASE + 0xE400)
+#define TEGRA2_EMC_BASE		(NV_PA_APB_MISC_BASE + 0xF400)
 #define TEGRA2_FUSE_BASE	(NV_PA_APB_MISC_BASE + 0xF800)
 #define NV_PA_CSITE_BASE	0x70040000
 #define TEGRA_USB1_BASE		0xC5000000
-- 
1.7.10.2