[U-Boot] [next PATCH v2 2/2] ARM: mvebu: add additional information to board_add_ram_info()

[Chris Packham]

From: Joshua Scott <joshua.scott at alliedtelesis.co.nz>

Display more information about the current RAM configuration. With these
changes the output on a 88F6820 board is

  SoC:   MV88F6820-A0 at 1600 MHz
  DRAM:  2 GiB (800 MHz, 32-bit, ECC not enabled)

Signed-off-by: Joshua Scott <joshua.scott at alliedtelesis.co.nz>
Signed-off-by: Chris Packham <judge.packham at gmail.com>
---
One of the hardware designers at $dayjob expressed a desire to keep
track of various tweaks to the DDR setup during hardware debugging
sessions. This is the result.

I've based this on what is available for the fsl platforms. It might be
nice to add a few more things but I'm concious of keeping the
information relevant and succinct.

Changes in v2:
- A375 and A38x have 16/32b DDR bus

 arch/arm/mach-mvebu/dram.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/arm/mach-mvebu/dram.c b/arch/arm/mach-mvebu/dram.c
index e3f304c36683..55e9ad726a88 100644
--- a/arch/arm/mach-mvebu/dram.c
+++ b/arch/arm/mach-mvebu/dram.c
@@ -216,6 +216,35 @@ static int ecc_enabled(void)
 
 	return 0;
 }
+
+/* Return the width of the DRAM bus, or 0 for unknown. */
+static int bus_width(void)
+{
+	int full_width = 0;
+
+	if (reg_read(REG_SDRAM_CONFIG_ADDR) & (1 << REG_SDRAM_CONFIG_WIDTH_OFFS))
+		full_width = 1;
+
+	switch (mvebu_soc_family()) {
+	case MVEBU_SOC_AXP:
+	    return full_width ? 64 : 32;
+	    break;
+	case MVEBU_SOC_A375:
+	case MVEBU_SOC_A38X:
+	case MVEBU_SOC_MSYS:
+	    return full_width ? 32 : 16;
+	default:
+	    return 0;
+	}
+}
+
+static int cycle_mode(void)
+{
+	int val = reg_read(REG_DUNIT_CTRL_LOW_ADDR);
+
+	return (val >> REG_DUNIT_CTRL_LOW_2T_OFFS) & REG_DUNIT_CTRL_LOW_2T_MASK;
+}
+
 #else
 static void dram_ecc_scrubbing(void)
 {
@@ -295,10 +324,26 @@ int dram_init_banksize(void)
 void board_add_ram_info(int use_default)
 {
 	struct sar_freq_modes sar_freq;
+	int mode;
+	int width;
 
 	get_sar_freq(&sar_freq);
 	printf(" (%d MHz, ", sar_freq.d_clk);
 
+	width = bus_width();
+	if (width)
+		printf("%d-bit, ", width);
+
+	mode = cycle_mode();
+	/* Mode 0 = Single cycle
+	 * Mode 1 = Two cycles   (2T)
+	 * Mode 2 = Three cycles (3T)
+	 */
+	if (mode == 1)
+		printf("2T, ");
+	if (mode == 2)
+		printf("3T, ");
+
 	if (ecc_enabled())
 		printf("ECC");
 	else
-- 
2.14.1