ppc4xx: Enable Primordial Stack for 40x and Unify ECC Handling

This patch (Part 2 of 2):

* Rolls up a suite of changes to enable correct primordial stack and
  global data handling when the data cache is used for such a purpose
  for PPC40x-variants (i.e. CFG_INIT_DCACHE_CS).

* Related to the first, unifies DDR2 SDRAM and ECC initialization by
  eliminating redundant ECC initialization implementations and moving
  redundant SDRAM initialization out of board code into shared 4xx
  code.

* Enables MCSR visibility on the 405EX(r).

* Enables the use of the data cache for initial RAM on
  both AMCC's Kilauea and Makalu and removes a redundant
  CFG_POST_MEMORY flag from each board's CONFIG_POST value.

  - Removed, per Stefan Roese's request, defunct memory.c file for
    Makalu and rolled sdram_init from it into makalu.c.

With respect to the 4xx DDR initialization and ECC unification, there
is certainly more work that can and should be done (file renaming,
etc.). However, that can be handled at a later date on a second or
third pass. As it stands, this patch moves things forward in an
incremental yet positive way for those platforms that utilize this
code and the features associated with it.

Signed-off-by: Grant Erickson <gerickson@nuovations.com>
Signed-off-by: Stefan Roese <sr@denx.de>

2 files changed, 125 insertions, 107 deletions

diff --git a/board/amcc/kilauea/init.S b/board/amcc/kilauea/init.S
index 8cd534c..bf47d6b 100644
--- a/board/amcc/kilauea/init.S
+++ b/board/amcc/kilauea/init.S
@@ -1,8 +1,11 @@
 /*
+ * Copyright (c) 2008 Nuovation System Designs, LLC
+ *   Grant Erickson <gerickson@nuovations.com>
+ *
  * (C) Copyright 2007-2008
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
- * Based on code provided from UDTech and AMCC
+ * Originally based on code provided from UDTech and AMCC
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -30,125 +33,135 @@
 #include <ppc_defs.h>
 
 #define mtsdram_as(reg, value)		\
-	addi    r4,0,reg	;	\
-	mtdcr   memcfga,r4	;	\
-	addis   r4,0,value@h	;	\
-	ori     r4,r4,value@l	;	\
-	mtdcr   memcfgd,r4	;
+	addi	r4,0,reg	;	\
+	mtdcr	memcfga,r4	;	\
+	addis	r4,0,value@h	;	\
+	ori	r4,r4,value@l	;	\
+	mtdcr	memcfgd,r4	;
+
+#if defined(CONFIG_DDR_ECC)
+	.extern ecc_init
+#endif /* defined(CONFIG_DDR_ECC) */
 
 	.globl  ext_bus_cntlr_init
 ext_bus_cntlr_init:
+#if !defined(CFG_INIT_DCACHE_CS)
 #if !defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL)
 
 	/*
-	 * DDR2 setup
+	 * DDR2 SDRAM Controller Setup
 	 */
 
-	/* Following the DDR Core Manual, here is the initialization */
-
-	/* Step 1 */
-
-	/* Step 2 */
-
-	/* Step 3 */
-
-	/* base=00000000, size=256MByte (6), mode=7 (n*10*8) */
-	mtsdram_as(SDRAM_MB0CF, 0x00006701);
-
-	/* SET SDRAM_MB1CF - Not enabled */
-	mtsdram_as(SDRAM_MB1CF, 0x00000000);
-
-	/* SET SDRAM_MB2CF  - Not enabled */
-	mtsdram_as(SDRAM_MB2CF, 0x00000000);
-
-	/* SET SDRAM_MB3CF  - Not enabled */
-	mtsdram_as(SDRAM_MB3CF, 0x00000000);
-
-	/* SDRAM_CLKTR: Adv Addr clock by 180 deg */
-	mtsdram_as(SDRAM_CLKTR, 0x80000000);
-
-	/* Refresh Time register (0x30) Refresh every 7.8125uS */
-	mtsdram_as(SDRAM_RTR, 0x06180000);
+	/* Set Memory Bank Configuration Registers */
+	mtsdram_as(SDRAM_MB0CF, CFG_SDRAM0_MB0CF);
+	mtsdram_as(SDRAM_MB1CF, CFG_SDRAM0_MB1CF);
+	mtsdram_as(SDRAM_MB2CF, CFG_SDRAM0_MB2CF);
+	mtsdram_as(SDRAM_MB3CF, CFG_SDRAM0_MB3CF);
+
+	/* Set Memory Clock Timing Register */
+	mtsdram_as(SDRAM_CLKTR, CFG_SDRAM0_CLKTR);
+
+	/* Set Refresh Time Register */
+	mtsdram_as(SDRAM_RTR, CFG_SDRAM0_RTR);
+
+	/* Set SDRAM Timing Registers */
+	mtsdram_as(SDRAM_SDTR1, CFG_SDRAM0_SDTR1);
+	mtsdram_as(SDRAM_SDTR2, CFG_SDRAM0_SDTR2);
+	mtsdram_as(SDRAM_SDTR3, CFG_SDRAM0_SDTR3);
+
+	/* Set Mode and Extended Mode Registers */
+	mtsdram_as(SDRAM_MMODE, CFG_SDRAM0_MMODE);
+	mtsdram_as(SDRAM_MEMODE, CFG_SDRAM0_MEMODE);
+
+	/* Set Memory Controller Options 1 Register */
+	mtsdram_as(SDRAM_MCOPT1, CFG_SDRAM0_MCOPT1);
+
+	/* Set Manual Initialization Control Registers */
+	mtsdram_as(SDRAM_INITPLR0, CFG_SDRAM0_INITPLR0);
+	mtsdram_as(SDRAM_INITPLR1, CFG_SDRAM0_INITPLR1);
+	mtsdram_as(SDRAM_INITPLR2, CFG_SDRAM0_INITPLR2);
+	mtsdram_as(SDRAM_INITPLR3, CFG_SDRAM0_INITPLR3);
+	mtsdram_as(SDRAM_INITPLR4, CFG_SDRAM0_INITPLR4);
+	mtsdram_as(SDRAM_INITPLR5, CFG_SDRAM0_INITPLR5);
+	mtsdram_as(SDRAM_INITPLR6, CFG_SDRAM0_INITPLR6);
+	mtsdram_as(SDRAM_INITPLR7, CFG_SDRAM0_INITPLR7);
+	mtsdram_as(SDRAM_INITPLR8, CFG_SDRAM0_INITPLR8);
+	mtsdram_as(SDRAM_INITPLR9, CFG_SDRAM0_INITPLR9);
+	mtsdram_as(SDRAM_INITPLR10, CFG_SDRAM0_INITPLR10);
+	mtsdram_as(SDRAM_INITPLR11, CFG_SDRAM0_INITPLR11);
+	mtsdram_as(SDRAM_INITPLR12, CFG_SDRAM0_INITPLR12);
+	mtsdram_as(SDRAM_INITPLR13, CFG_SDRAM0_INITPLR13);
+	mtsdram_as(SDRAM_INITPLR14, CFG_SDRAM0_INITPLR14);
+	mtsdram_as(SDRAM_INITPLR15, CFG_SDRAM0_INITPLR15);
+
+	/* Set On-Die Termination Registers */
+	mtsdram_as(SDRAM_CODT, CFG_SDRAM0_CODT);
+	mtsdram_as(SDRAM_MODT0, CFG_SDRAM0_MODT0);
+	mtsdram_as(SDRAM_MODT1, CFG_SDRAM0_MODT1);
+
+	/* Set Write Timing Register */
+	mtsdram_as(SDRAM_WRDTR, CFG_SDRAM0_WRDTR);
 
-	/* SDRAM_SDTR1 */
-	mtsdram_as(SDRAM_SDTR1, 0x80201000);
-
-	/* SDRAM_SDTR2	*/
-	mtsdram_as(SDRAM_SDTR2, 0x32204232);
+	/*
+	 * Start Initialization by SDRAM0_MCOPT2[SREN] = 0 and
+	 * SDRAM0_MCOPT2[IPTR] = 1
+	 */
+	mtsdram_as(SDRAM_MCOPT2, SDRAM_MCOPT2_SREN_EXIT | \
+				 SDRAM_MCOPT2_IPTR_EXECUTE);
 
-	/* SDRAM_SDTR3	*/
-	mtsdram_as(SDRAM_SDTR3, 0x080b0d1a);
+	/*
+	 * Poll SDRAM0_MCSTAT[MIC] for assertion to indicate the
+	 * completion of initialization.
+	 *
+	 *   do {
+	 *           mfsdram(SDRAM_MCSTAT, val);
+	 *   } while ((val & SDRAM_MCSTAT_MIC_MASK) != SDRAM_MCSTAT_MIC_COMP);
+	 */
+	li	r4,SDRAM_MCSTAT
+	lis	r2,SDRAM_MCSTAT_MIC_COMP@h
+	ori	r2,r2,SDRAM_MCSTAT_MIC_COMP@l
+0:	mtdcr	memcfga,r4
+	mfdcr	r3,memcfgd
+	clrrwi	r3,r3,31
+	cmpw	cr7,r3,r2
+	bne+	cr7,0b
+
+	/* Set Delay Control Registers */
+	mtsdram_as(SDRAM_DLCR, CFG_SDRAM0_DLCR);
+	mtsdram_as(SDRAM_RDCC, CFG_SDRAM0_RDCC);
+	mtsdram_as(SDRAM_RQDC, CFG_SDRAM0_RQDC);
+	mtsdram_as(SDRAM_RFDC, CFG_SDRAM0_RFDC);
 
-	mtsdram_as(SDRAM_MMODE, 0x00000442);
-	mtsdram_as(SDRAM_MEMODE, 0x00000404);
+	/*
+	 * Enable Controller by SDRAM0_MCOPT2[DCEN] = 1:
+	 *
+	 *   mcopt2 = mfsdram(SDRAM_MCOPT2);
+	 */
+	li	r4,SDRAM_MCOPT2
+	mtdcr	memcfga,r4
+	mfdcr	r3,memcfgd
 
-	/* SDRAM0_MCOPT1 (0X20) No ECC Gen */
-	mtsdram_as(SDRAM_MCOPT1, 0x04322000);
+	/*
+	 *   mtsdram(SDRAM_MCOPT2, mcopt2 | SDRAM_MCOPT2_DCEN_ENABLE);
+	 */
+	mtdcr	memcfga,r4
+	oris	r3,r3,SDRAM_MCOPT2_DCEN_ENABLE@h
+	ori	r3,r3,SDRAM_MCOPT2_DCEN_ENABLE@l
+	mtdcr	memcfgd,r3
 
-	/* NOP */
-	mtsdram_as(SDRAM_INITPLR0, 0xa8380000);
-	/* precharge 3 DDR clock cycle */
-	mtsdram_as(SDRAM_INITPLR1, 0x81900400);
-	/* EMR2 twr = 2tck */
-	mtsdram_as(SDRAM_INITPLR2, 0x81020000);
-	/* EMR3  twr = 2tck */
-	mtsdram_as(SDRAM_INITPLR3, 0x81030000);
-	/* EMR DLL ENABLE twr = 2tck */
-	mtsdram_as(SDRAM_INITPLR4, 0x81010404);
-	/* MR w/ DLL reset
-	 * Note: 5 is CL.  May need to be changed
+#if defined(CONFIG_DDR_ECC)
+	/*
+	 *   ecc_init(CFG_SDRAM_BASE, CFG_MBYTES_SDRAM << 20);
 	 */
-	mtsdram_as(SDRAM_INITPLR5, 0x81000542);
-	/* precharge 3 DDR clock cycle */
-	mtsdram_as(SDRAM_INITPLR6, 0x81900400);
-	/* Auto-refresh trfc = 26tck */
-	mtsdram_as(SDRAM_INITPLR7, 0x8D080000);
-	/* Auto-refresh trfc = 26tck */
-	mtsdram_as(SDRAM_INITPLR8, 0x8D080000);
-	/* Auto-refresh */
-	mtsdram_as(SDRAM_INITPLR9, 0x8D080000);
-	/* Auto-refresh */
-	mtsdram_as(SDRAM_INITPLR10, 0x8D080000);
-	/* MRS - normal operation; wait 2 cycle (set wait to tMRD) */
-	mtsdram_as(SDRAM_INITPLR11, 0x81000442);
-	mtsdram_as(SDRAM_INITPLR12, 0x81010780);
-	mtsdram_as(SDRAM_INITPLR13, 0x81010400);
-	mtsdram_as(SDRAM_INITPLR14, 0x00000000);
-	mtsdram_as(SDRAM_INITPLR15, 0x00000000);
-
-	/* SET MCIF0_CODT   Die Termination On */
-	mtsdram_as(SDRAM_CODT, 0x0080f837);
-	mtsdram_as(SDRAM_MODT0, 0x01800000);
-	mtsdram_as(SDRAM_MODT1, 0x00000000);
-
-	mtsdram_as(SDRAM_WRDTR, 0x00000000);
-
-	/* SDRAM0_MCOPT2 (0X21) Start initialization */
-	mtsdram_as(SDRAM_MCOPT2, 0x20000000);
-
-	/* Step 5 */
-	lis     r3,0x1	/* 400000 =  wait 100ms */
-	mtctr   r3
-
-pll_wait:
-	bdnz	pll_wait
-
-	/* Step 6 */
-
-	/* SDRAM_DLCR */
-	mtsdram_as(SDRAM_DLCR, 0x030000a5);
-
-	/* SDRAM_RDCC */
-	mtsdram_as(SDRAM_RDCC, 0x40000000);
-
-	/* SDRAM_RQDC */
-	mtsdram_as(SDRAM_RQDC, 0x80000038);
-
-	/* SDRAM_RFDC */
-	mtsdram_as(SDRAM_RFDC, 0x00000209);
-
-	/* Enable memory controller */
-	mtsdram_as(SDRAM_MCOPT2, 0x28000000);
-#endif /* #ifndef CONFIG_NAND_U_BOOT */
+	mflr	r13
+	lis	r3,CFG_SDRAM_BASE@h
+	ori	r3,r3,CFG_SDRAM_BASE@l
+	lis	r4,(CFG_MBYTES_SDRAM << 20)@h
+	ori	r4,r4,(CFG_MBYTES_SDRAM << 20)@l
+	bl	ecc_init
+	mtlr	r13
+#endif /* defined(CONFIG_DDR_ECC) */
+#endif /* !defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL) */
+#endif /* !defined(CFG_INIT_DCACHE_CS) */
 
 	blr
diff --git a/board/amcc/kilauea/memory.c b/board/amcc/kilauea/memory.c
index 1d7a3fa..b7e2344 100644
--- a/board/amcc/kilauea/memory.c
+++ b/board/amcc/kilauea/memory.c
@@ -1,4 +1,7 @@
 /*
+ * Copyright (c) 2008 Nuovation System Designs, LLC
+ *   Grant Erickson <gerickson@nuovations.com>
+ *
  * (C) Copyright 2007
  * Stefan Roese, DENX Software Engineering, sr@denx.de.
  *
@@ -30,10 +33,12 @@ void sdram_init(void)
 	return;
 }
 
+#if defined(CONFIG_NAND_U_BOOT)
 long int initdram(int board_type)
 {
 	return (CFG_MBYTES_SDRAM << 20);
 }
+#endif /* defined(CONFIG_NAND_U_BOOT) */
 
 #if defined(CFG_DRAM_TEST)
 int testdram (void)