From c021880ac5837154ca51b9d84e6b75f39b64aabe Mon Sep 17 00:00:00 2001
From: wdenk <wdenk>
Date: Thu, 27 Mar 2003 12:09:35 +0000
Subject: * Add support for MIPS32 4Kc CPUs

* Add support for INCA-IP Board
---
 board/incaip/incaip.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 board/incaip/incaip.c

(limited to 'board/incaip/incaip.c')

diff --git a/board/incaip/incaip.c b/board/incaip/incaip.c
new file mode 100644
index 0000000..72f1c21
--- /dev/null
+++ b/board/incaip/incaip.c
@@ -0,0 +1,129 @@
+/*
+ * (C) Copyright 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/addrspace.h>
+#include <asm/inca-ip.h>
+
+
+static ulong max_sdram_size(void)
+{
+	/* The only supported SDRAM data width is 16bit.
+	 */
+#define CFG_DW	2
+
+	/* The only supported number of SDRAM banks is 4.
+	 */
+#define CFG_NB	4
+
+	ulong cfgpb0 = *INCA_IP_SDRAM_MC_CFGPB0;
+	int   cols   = cfgpb0 & 0xF;
+	int   rows   = (cfgpb0 & 0xF0) >> 4;
+	ulong size   = (1 << (rows + cols)) * CFG_DW * CFG_NB;
+
+	return size;
+}
+
+/*
+ * Check memory range for valid RAM. A simple memory test determines
+ * the actually available RAM size between addresses `base' and
+ * `base + maxsize'. Some (not all) hardware errors are detected:
+ * - short between address lines
+ * - short between data lines
+ */
+
+static long int dram_size(long int *base, long int maxsize)
+{
+	volatile long int *addr;
+	ulong cnt, val;
+	ulong save[32];			/* to make test non-destructive */
+	unsigned char i = 0;
+
+	for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
+		addr = base + cnt;		/* pointer arith! */
+
+		save[i++] = *addr;
+		*addr = ~cnt;
+	}
+
+	/* write 0 to base address */
+	addr = base;
+	save[i] = *addr;
+	*addr = 0;
+
+	/* check at base address */
+	if ((val = *addr) != 0) {
+		*addr = save[i];
+		return (0);
+	}
+
+	for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) {
+		addr = base + cnt;		/* pointer arith! */
+
+		val = *addr;
+		*addr = save[--i];
+
+		if (val != (~cnt)) {
+			return (cnt * sizeof (long));
+		}
+	}
+	return (maxsize);
+}
+
+long int initdram(int board_type)
+{
+	int   rows, cols, best_val = *INCA_IP_SDRAM_MC_CFGPB0;
+	ulong size, max_size       = 0;
+	ulong our_address;
+
+	asm volatile ("move %0, $25" : "=r" (our_address) :);
+
+		/* Can't probe for RAM size unless we are running from Flash.
+		 */
+	if (PHYSADDR(our_address) < PHYSADDR(PHYS_FLASH_1))
+	{
+		return max_sdram_size();
+	}
+
+	for (cols = 0x8; cols <= 0xC; cols++)
+	{
+		for (rows = 0xB; rows <= 0xD; rows++)
+		{
+			*INCA_IP_SDRAM_MC_CFGPB0 = (0x14 << 8) |
+			                           (rows << 4) | cols;
+			size = dram_size((ulong *)CFG_SDRAM_BASE,
+			                                     max_sdram_size());
+
+			if (size > max_size)
+			{
+				best_val = *INCA_IP_SDRAM_MC_CFGPB0;
+				max_size = size;
+			}
+		}
+	}
+
+	*INCA_IP_SDRAM_MC_CFGPB0 = best_val;
+	return max_size;
+}
+
-- 
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