[PATCH] PPC4xx: Add 440SP(e) DDR2 SPD DIMM support

This patch adds support for the DDR2 controller used on the
440SP and 440SPe. It is tested on the Katmai (440SPe) eval
board and works fine with the following DIMM modules:

- Corsair CM2X512-5400C4 (512MByte per DIMM)
- Kingston ValueRAM KVR667D2N5/512 (512MByte per DIMM)
- Kingston ValueRAM KVR667D2N5K2/2G (1GByte per DIMM)

This patch also adds the nice functionality to dynamically
create the TLB entries for the SDRAM (tlb.c). So we should
never run into such problems with wrong (too short) TLB
initialization again on these platforms.

Signed-off-by: Stefan Roese <sr@denx.de>

1 files changed, 184 insertions, 0 deletions

diff --git a/cpu/ppc4xx/tlb.c b/cpu/ppc4xx/tlb.c
new file mode 100644
index 000000000..8c605591b
--- /dev/null
+++ b/cpu/ppc4xx/tlb.c
@@ -0,0 +1,184 @@
+/*
+ * (C) Copyright 2007
+ * Stefan Roese, DENX Software Engineering, sr@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>
+
+#if defined(CONFIG_440)
+
+#include <ppc4xx.h>
+#include <ppc440.h>
+#include <asm/io.h>
+#include <asm/mmu.h>
+
+typedef struct region {
+	unsigned long base;
+	unsigned long size;
+	unsigned long tlb_word2_i_value;
+} region_t;
+
+static int add_tlb_entry(unsigned long base_addr,
+                         unsigned long tlb_word0_size_value,
+                         unsigned long tlb_word2_i_value)
+{
+	int i;
+	unsigned long tlb_word0_value;
+	unsigned long tlb_word1_value;
+	unsigned long tlb_word2_value;
+
+	/* First, find the index of a TLB entry not being used */
+	for (i=0; i<PPC4XX_TLB_SIZE; i++) {
+		tlb_word0_value = mftlb1(i);
+		if ((tlb_word0_value & TLB_WORD0_V_MASK) == TLB_WORD0_V_DISABLE)
+			break;
+	}
+	if (i >= PPC4XX_TLB_SIZE)
+		return -1;
+
+	/* Second, create the TLB entry */
+	tlb_word0_value = TLB_WORD0_EPN_ENCODE(base_addr) | TLB_WORD0_V_ENABLE |
+		TLB_WORD0_TS_0 | tlb_word0_size_value;
+	tlb_word1_value = TLB_WORD1_RPN_ENCODE(base_addr) | TLB_WORD1_ERPN_ENCODE(0);
+	tlb_word2_value = TLB_WORD2_U0_DISABLE | TLB_WORD2_U1_DISABLE |
+		TLB_WORD2_U2_DISABLE | TLB_WORD2_U3_DISABLE |
+		TLB_WORD2_W_DISABLE | tlb_word2_i_value |
+		TLB_WORD2_M_DISABLE | TLB_WORD2_G_DISABLE |
+		TLB_WORD2_E_DISABLE | TLB_WORD2_UX_ENABLE |
+		TLB_WORD2_UW_ENABLE | TLB_WORD2_UR_ENABLE |
+		TLB_WORD2_SX_ENABLE | TLB_WORD2_SW_ENABLE |
+		TLB_WORD2_SR_ENABLE;
+
+	/* Wait for all memory accesses to complete */
+	sync();
+
+	/* Third, add the TLB entries */
+	mttlb1(i, tlb_word0_value);
+	mttlb2(i, tlb_word1_value);
+	mttlb3(i, tlb_word2_value);
+
+	/* Execute an ISYNC instruction so that the new TLB entry takes effect */
+	asm("isync");
+
+	return 0;
+}
+
+static void program_tlb_addr(unsigned long base_addr, unsigned long mem_size,
+                             unsigned long tlb_word2_i_value)
+{
+	int rc;
+	int tlb_i;
+
+	tlb_i = tlb_word2_i_value;
+	while (mem_size != 0) {
+		rc = 0;
+		/* Add the TLB entries in to map the region. */
+		if (((base_addr & TLB_256MB_ALIGN_MASK) == base_addr) &&
+		    (mem_size >= TLB_256MB_SIZE)) {
+			/* Add a 256MB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256MB, tlb_i)) == 0) {
+				mem_size -= TLB_256MB_SIZE;
+				base_addr += TLB_256MB_SIZE;
+			}
+		} else if (((base_addr & TLB_16MB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_16MB_SIZE)) {
+			/* Add a 16MB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16MB, tlb_i)) == 0) {
+				mem_size -= TLB_16MB_SIZE;
+				base_addr += TLB_16MB_SIZE;
+			}
+		} else if (((base_addr & TLB_1MB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_1MB_SIZE)) {
+			/* Add a 1MB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1MB, tlb_i)) == 0) {
+				mem_size -= TLB_1MB_SIZE;
+				base_addr += TLB_1MB_SIZE;
+			}
+		} else if (((base_addr & TLB_256KB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_256KB_SIZE)) {
+			/* Add a 256KB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256KB, tlb_i)) == 0) {
+				mem_size -= TLB_256KB_SIZE;
+				base_addr += TLB_256KB_SIZE;
+			}
+		} else if (((base_addr & TLB_64KB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_64KB_SIZE)) {
+			/* Add a 64KB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_64KB, tlb_i)) == 0) {
+				mem_size -= TLB_64KB_SIZE;
+				base_addr += TLB_64KB_SIZE;
+			}
+		} else if (((base_addr & TLB_16KB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_16KB_SIZE)) {
+			/* Add a 16KB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16KB, tlb_i)) == 0) {
+				mem_size -= TLB_16KB_SIZE;
+				base_addr += TLB_16KB_SIZE;
+			}
+		} else if (((base_addr & TLB_4KB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_4KB_SIZE)) {
+			/* Add a 4KB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_4KB, tlb_i)) == 0) {
+				mem_size -= TLB_4KB_SIZE;
+				base_addr += TLB_4KB_SIZE;
+			}
+		} else if (((base_addr & TLB_1KB_ALIGN_MASK) == base_addr) &&
+			   (mem_size >= TLB_1KB_SIZE)) {
+			/* Add a 1KB TLB entry */
+			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1KB, tlb_i)) == 0) {
+				mem_size -= TLB_1KB_SIZE;
+				base_addr += TLB_1KB_SIZE;
+			}
+		} else {
+			printf("ERROR: no TLB size exists for the base address 0x%0X.\n",
+				base_addr);
+		}
+
+		if (rc != 0)
+			printf("ERROR: no TLB entries available for the base addr 0x%0X.\n",
+				base_addr);
+	}
+
+	return;
+}
+
+/*
+ * Program one (or multiple) TLB entries for one memory region
+ *
+ * Common usage for boards with SDRAM DIMM modules to dynamically
+ * configure the TLB's for the SDRAM
+ */
+void program_tlb(u32 start, u32 size)
+{
+	region_t region_array;
+
+	region_array.base = start;
+	region_array.size = size;
+	region_array.tlb_word2_i_value = TLB_WORD2_I_ENABLE;	/* disable cache (for now) */
+
+	/* Call the routine to add in the tlb entries for the memory regions */
+	program_tlb_addr(region_array.base, region_array.size,
+			 region_array.tlb_word2_i_value);
+
+	return;
+}
+
+#endif /* CONFIG_440 */