Persimmon: drop useless DDR3 voltage code copied from Inagua

Inagua can use GPIOs 178,179 to switch VMEM to 1.5, 1.35 or 1.25 V,
which it does according to data read from the SO-DIMM's SPD EEPROM.

On Persimmon (according to DB-FT1 rev. D schematics) both GPIOs are
unconnected, there is no way to change the 1.5 V DDR3 voltage (save
unsoldering a resistor). The whole code copied over from Inagua is
useless.

Removed the code, instead a comment hints at Inagua, for people who do designs
based on Persimmon but do have a way to change VMEM.

The line ...->DDR3Voltage = VOLT1_5; is supposed to make the AGESA DDR3 code
select the RAM timings for the actually supplied voltage instead of the
hoped-for but unavailable lower voltage. I have no idea how to test this, but
in any case it can't hurt.

Change-Id: Id098e09418b665645814a6ee2d41a3bff72238ba
Signed-off-by: Jens Rottmann <JRottmann@LiPPERTembedded.de>
Reviewed-on: http://review.coreboot.org/2448
Tested-by: build bot (Jenkins)
Reviewed-by: Peter Stuge <peter@stuge.se>

1 files changed, 4 insertions, 78 deletions

diff --git a/src/mainboard/amd/persimmon/BiosCallOuts.c b/src/mainboard/amd/persimmon/BiosCallOuts.c
index 0711d96f17..4db6e753ee 100644
--- a/src/mainboard/amd/persimmon/BiosCallOuts.c
+++ b/src/mainboard/amd/persimmon/BiosCallOuts.c
@@ -445,84 +445,10 @@ AGESA_STATUS BiosHookBeforeDQSTraining (UINT32 Func, UINT32 Data, VOID *ConfigPt
 /*	Call the host environment interface to provide a user hook opportunity. */
 AGESA_STATUS BiosHookBeforeDramInit (UINT32 Func, UINT32 Data, VOID *ConfigPtr)
 {
-	AGESA_STATUS		Status;
-	UINTN			 FcnData;
-	MEM_DATA_STRUCT	 *MemData;
-	UINT32			AcpiMmioAddr;
-	UINT32			GpioMmioAddr;
-	UINT8			 Data8;
-	UINT16			Data16;
-	UINT8			 TempData8;
-
-	FcnData = Data;
-	MemData = ConfigPtr;
-
-	Status	= AGESA_SUCCESS;
-	/* Get SB MMIO Base (AcpiMmioAddr) */
-	WriteIo8 (0xCD6, 0x27);
-	Data8	 = ReadIo8(0xCD7);
-	Data16	= Data8<<8;
-	WriteIo8 (0xCD6, 0x26);
-	Data8	 = ReadIo8(0xCD7);
-	Data16	|= Data8;
-	AcpiMmioAddr = (UINT32)Data16 << 16;
-	GpioMmioAddr = AcpiMmioAddr + GPIO_BASE;
-
-	Data8 = Read64Mem8(GpioMmioAddr+SB_GPIO_REG178);
-	Data8 &= ~BIT5;
-	TempData8	= Read64Mem8 (GpioMmioAddr+SB_GPIO_REG178);
-	TempData8 &= 0x03;
-	TempData8 |= Data8;
-	Write64Mem8(GpioMmioAddr+SB_GPIO_REG178, TempData8);
-
-	Data8 |= BIT2+BIT3;
-	Data8 &= ~BIT4;
-	TempData8	= Read64Mem8 (GpioMmioAddr+SB_GPIO_REG178);
-	TempData8 &= 0x23;
-	TempData8 |= Data8;
-	Write64Mem8(GpioMmioAddr+SB_GPIO_REG178, TempData8);
-
-	Data8 = Read64Mem8(GpioMmioAddr+SB_GPIO_REG179);
-	Data8 &= ~BIT5;
-	TempData8	= Read64Mem8 (GpioMmioAddr+SB_GPIO_REG179);
-	TempData8 &= 0x03;
-	TempData8 |= Data8;
-	Write64Mem8(GpioMmioAddr+SB_GPIO_REG179, TempData8);
-
-	Data8 |= BIT2+BIT3;
-	Data8 &= ~BIT4;
-	TempData8	= Read64Mem8 (GpioMmioAddr+SB_GPIO_REG179);
-	TempData8 &= 0x23;
-	TempData8 |= Data8;
-	Write64Mem8(GpioMmioAddr+SB_GPIO_REG179, TempData8);
-
-	switch(MemData->ParameterListPtr->DDR3Voltage){
-	case VOLT1_35:
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG178);
-		Data8 &= ~(UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG178, Data8);
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG179);
-		Data8 |= (UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG179, Data8);
-		break;
-	case VOLT1_25:
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG178);
-		Data8 &= ~(UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG178, Data8);
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG179);
-		Data8 &= ~(UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG179, Data8);
-		break;
-	case VOLT1_5:
-	default:
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG178);
-		Data8 |= (UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG178, Data8);
-		Data8 =	Read64Mem8 (GpioMmioAddr+SB_GPIO_REG179);
-		Data8 &= ~(UINT8)BIT6;
-		Write64Mem8(GpioMmioAddr+SB_GPIO_REG179, Data8);
-	}
-	return Status;
+	// Unlike e.g. AMD Inagua, Persimmon is unable to vary the RAM voltage.
+	// Make sure the right speed settings are selected.
+	((MEM_DATA_STRUCT*)ConfigPtr)->ParameterListPtr->DDR3Voltage = VOLT1_5;
+	return AGESA_SUCCESS;
 }
 
 /*	Call the host environment interface to provide a user hook opportunity. */