[U-Boot] [PATCH 1/3 v2] 83xx: Default to using DMA to initialize SDRAM

[Peter Tyser]

When SDRAM ECC is enabled and CONFIG_ECC_INIT_VIA_DDRCONTROLLER is not
defined use DMA to set SDRAM to a known state.  Previously a sequence of
64-bit stores was used.

Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
---
 cpu/mpc83xx/spd_sdram.c  |   57 +++------------------------------------------
 drivers/dma/fsl_dma.c    |   16 +++++++++----
 include/asm-ppc/config.h |    7 ++---
 3 files changed, 18 insertions(+), 62 deletions(-)

diff --git a/cpu/mpc83xx/spd_sdram.c b/cpu/mpc83xx/spd_sdram.c
index 0f61180..8a09a7d 100644
--- a/cpu/mpc83xx/spd_sdram.c
+++ b/cpu/mpc83xx/spd_sdram.c
@@ -825,67 +825,18 @@ long int spd_sdram()
 
 #if defined(CONFIG_DDR_ECC) && !defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER)
 /*
- * Use timebase counter, get_timer() is not availabe
- * at this point of initialization yet.
- */
-static __inline__ unsigned long get_tbms (void)
-{
-	unsigned long tbl;
-	unsigned long tbu1, tbu2;
-	unsigned long ms;
-	unsigned long long tmp;
-
-	ulong tbclk = get_tbclk();
-
-	/* get the timebase ticks */
-	do {
-		asm volatile ("mftbu %0":"=r" (tbu1):);
-		asm volatile ("mftb %0":"=r" (tbl):);
-		asm volatile ("mftbu %0":"=r" (tbu2):);
-	} while (tbu1 != tbu2);
-
-	/* convert ticks to ms */
-	tmp = (unsigned long long)(tbu1);
-	tmp = (tmp << 32);
-	tmp += (unsigned long long)(tbl);
-	ms = tmp/(tbclk/1000);
-
-	return ms;
-}
-
-/*
  * Initialize all of memory for ECC, then enable errors.
  */
 void ddr_enable_ecc(unsigned int dram_size)
 {
 	volatile immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
 	volatile ddr83xx_t *ddr= &immap->ddr;
-	unsigned long t_start, t_end;
-	register u64 *p;
-	register uint size;
-	unsigned int pattern[2];
-
-	icache_enable();
-	t_start = get_tbms();
-	pattern[0] = 0xdeadbeef;
-	pattern[1] = 0xdeadbeef;
-
-#if defined(CONFIG_DDR_ECC_INIT_VIA_DMA)
-	dma_meminit(pattern[0], dram_size);
-#else
-	debug("ddr init: CPU FP write method\n");
-	size = dram_size;
-	for (p = 0; p < (u64*)(size); p++) {
-		ppcDWstore((u32*)p, pattern);
-	}
-	__asm__ __volatile__ ("sync");
-#endif
 
-	t_end = get_tbms();
-	icache_disable();
+	debug("\nInitializing ECC!\n");
+
+	dma_meminit(0xdeadbeef, dram_size);
 
-	debug("\nREADY!!\n");
-	debug("ddr init duration: %ld ms\n", t_end - t_start);
+	debug("\nREADY!\n");
 
 	/* Clear All ECC Errors */
 	if ((ddr->err_detect & ECC_ERROR_DETECT_MME) == ECC_ERROR_DETECT_MME)
diff --git a/drivers/dma/fsl_dma.c b/drivers/dma/fsl_dma.c
index df33e7a..90a96dd 100644
--- a/drivers/dma/fsl_dma.c
+++ b/drivers/dma/fsl_dma.c
@@ -140,17 +140,19 @@ int dmacpy(phys_addr_t dest, phys_addr_t src, phys_size_t count) {
 }
 
 /*
- * 85xx/86xx use dma to initialize SDRAM when !CONFIG_ECC_INIT_VIA_DDRCONTROLLER
- * while 83xx uses dma to initialize SDRAM when CONFIG_DDR_ECC_INIT_VIA_DMA
+ * Use dma to initialize SDRAM when !CONFIG_ECC_INIT_VIA_DDRCONTROLLER
  */
-#if ((!defined CONFIG_MPC83xx && defined(CONFIG_DDR_ECC) &&	\
-	!defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER)) ||		\
-	(defined(CONFIG_MPC83xx) && defined(CONFIG_DDR_ECC_INIT_VIA_DMA)))
+#if (defined(CONFIG_DDR_ECC) && !defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER))
 void dma_meminit(uint val, uint size)
 {
 	uint *p = 0;
 	uint i = 0;
 
+#ifdef CONFIG_MPC83xx
+	/* Enabling the instruction cache greatly improves SDRAM init speed */
+	icache_enable();
+#endif
+
 	for (*p = 0; p < (uint *)(8 * 1024); p++) {
 		if (((uint)p & 0x1f) == 0)
 			ppcDcbz((ulong)p);
@@ -174,5 +176,9 @@ void dma_meminit(uint val, uint size)
 
 	for (i = 1; i < size / 0x800000; i++)
 		dmacpy((0x800000 * i), 0, 0x800000);
+
+#ifdef CONFIG_MPC83xx
+	icache_disable();
+#endif
 }
 #endif
diff --git a/include/asm-ppc/config.h b/include/asm-ppc/config.h
index ca143c7..01668a9 100644
--- a/include/asm-ppc/config.h
+++ b/include/asm-ppc/config.h
@@ -29,10 +29,9 @@
 #endif
 #endif
 
-#ifndef CONFIG_FSL_DMA
-#if ((!defined CONFIG_MPC83xx && defined(CONFIG_DDR_ECC) &&	\
-	!defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER)) ||		\
-	(defined(CONFIG_MPC83xx) && defined(CONFIG_DDR_ECC_INIT_VIA_DMA)))
+#if (defined(CONFIG_MPC83xx) || defined(CONFIG_MPC85xx) || \
+	defined(CONFIG_MPC86xx)) && !defined CONFIG_FSL_DMA
+#if (defined(CONFIG_DDR_ECC) && !defined(CONFIG_ECC_INIT_VIA_DDRCONTROLLER))
 #define CONFIG_FSL_DMA
 #endif
 #endif
-- 
1.6.2.1