Factor out casmap calculation. Gets rid of a warning.

Signed-off-by: Myles Watson <mylesgw@gmail.com>
Acked-by: Stefan Reinauer <stepan@coresystems.de>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5519 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 45 insertions, 67 deletions

diff --git a/src/northbridge/amd/lx/raminit.c b/src/northbridge/amd/lx/raminit.c
index 9014fb1de3..d2197a7583 100644
--- a/src/northbridge/amd/lx/raminit.c
+++ b/src/northbridge/amd/lx/raminit.c
@@ -238,46 +238,23 @@ static void set_refresh_rate(void)
 
 const uint8_t CASDDR[] = { 5, 5, 2, 6, 3, 7, 4, 0 };	/* 1(1.5), 1.5, 2, 2.5, 3, 3.5, 4, 0 */
 
-static void setCAS(void)
+static u8 getcasmap(u32 dimm, u16 glspeed)
 {
-/*;*****************************************************************************
-;*
-;*	setCAS
-;*	EEPROM byte usage: (18) SDRAM device attributes - CAS latency
-;*	EEPROM byte usage: (23) SDRAM Minimum Clock Cycle Time @ CLX -.5
-;*	EEPROM byte usage: (25) SDRAM Minimum Clock Cycle Time @ CLX -1
-;*
-;*	The CAS setting is based on the information provided in each DIMMs SPD.
-;*	 The speed at which a DIMM can run is described relative to the slowest
-;*	 CAS the DIMM supports. Each speed for the relative CAS settings is
-;*	 checked that it is within the GeodeLink speed. If it isn't within the GeodeLink
-;*	 speed, the CAS setting	 is removed from the list of good settings for
-;*	 the DIMM. This is done for both DIMMs and the lists are compared to
-;*	 find the lowest common CAS latency setting. If there are no CAS settings
-;*	 in common we out a ERROR_DIFF_DIMMS (78h) to port 80h and halt.
-;*
-;*	Entry:
-;*	Exit: Set fastest CAS Latency based on GeodeLink speed and SPD information.
-;*	Destroys: We really use everything !
-;*****************************************************************************/
-	uint16_t glspeed, dimm_speed;
-	uint8_t spd_byte, casmap0, casmap1, casmap_shift;
-	msr_t msr;
-
-	glspeed = GeodeLinkSpeed();
+	u16 dimm_speed;
+	u8 spd_byte, casmap, casmap_shift=0;
 
 	/**************************	 DIMM0	**********************************/
-	casmap0 = spd_read_byte(DIMM0, SPD_ACCEPTABLE_CAS_LATENCIES);
-	if (casmap0 != 0xFF) {
+	casmap = spd_read_byte(dimm, SPD_ACCEPTABLE_CAS_LATENCIES);
+	if (casmap != 0xFF) {
 		/* IF -.5 timing is supported, check -.5 timing > GeodeLink */
-		spd_byte = spd_read_byte(DIMM0, SPD_SDRAM_CYCLE_TIME_2ND);
+		spd_byte = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_2ND);
 		if (spd_byte != 0) {
 			/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
 			dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
 			if (dimm_speed >= glspeed) {
 				casmap_shift = 1; /* -.5 is a shift of 1 */
 				/* IF -1 timing is supported, check -1 timing > GeodeLink */
-				spd_byte = spd_read_byte(DIMM0, SPD_SDRAM_CYCLE_TIME_3RD);
+				spd_byte = spd_read_byte(dimm, SPD_SDRAM_CYCLE_TIME_3RD);
 				if (spd_byte != 0) {
 					/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
 					dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
@@ -290,52 +267,53 @@ static void setCAS(void)
 			}
 		}	/* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
 		/* set the casmap based on the shift to limit possible CAS settings */
-		spd_byte = 31 - __builtin_clz((uint32_t) casmap0);
+		spd_byte = 31 - __builtin_clz((uint32_t) casmap);
 		/* just want bits in the lower byte since we have to cast to a 32 */
-		casmap0 &= 0xFF << (spd_byte - casmap_shift);
+		casmap &= 0xFF << (spd_byte - casmap_shift);
 	} else {		/* No DIMM */
-		casmap0 = 0;
+		casmap = 0;
 	}
+	return casmap;
+}
 
-	/**************************	 DIMM1	**********************************/
-	casmap1 = spd_read_byte(DIMM1, SPD_ACCEPTABLE_CAS_LATENCIES);
-	if (casmap1 != 0xFF) {
-		/* IF -.5 timing is supported, check -.5 timing > GeodeLink */
-		spd_byte = spd_read_byte(DIMM1, SPD_SDRAM_CYCLE_TIME_2ND);
-		if (spd_byte != 0) {
-			/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
-			dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
-			if (dimm_speed >= glspeed) {
-				casmap_shift = 1; /* -.5 is a shift of 1 */
-				/* IF -1 timing is supported, check -1 timing > GeodeLink */
-				spd_byte = spd_read_byte(DIMM1, SPD_SDRAM_CYCLE_TIME_3RD);
-				if (spd_byte != 0) {
-					/* Turn SPD ns time into MHZ. Check what the asm does to this math. */
-					dimm_speed = 20000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F));
-					if (dimm_speed >= glspeed) {
-						casmap_shift = 2; /* -1 is a shift of 2 */
-					}
-					/* note that the -1 result doesn't need to change the available CAS map */
-				}	/* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
-			} else {
-				casmap_shift = 0;
-			}
-		}	/* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
-		/* set the casmap based on the shift to limit possible CAS settings */
-		spd_byte = 31 - __builtin_clz((uint32_t) casmap1);
-		/* just want bits in the lower byte since we have to cast to a 32 */
-		casmap1 &= 0xFF << (spd_byte - casmap_shift);
-	} else {		/* No DIMM */
-		casmap1 = 0;
-	}
+static void setCAS(void)
+{
+/*;*****************************************************************************
+;*
+;*	setCAS
+;*	EEPROM byte usage: (18) SDRAM device attributes - CAS latency
+;*	EEPROM byte usage: (23) SDRAM Minimum Clock Cycle Time @ CLX -.5
+;*	EEPROM byte usage: (25) SDRAM Minimum Clock Cycle Time @ CLX -1
+;*
+;*	The CAS setting is based on the information provided in each DIMMs SPD.
+;*	 The speed at which a DIMM can run is described relative to the slowest
+;*	 CAS the DIMM supports. Each speed for the relative CAS settings is
+;*	 checked that it is within the GeodeLink speed. If it isn't within the GeodeLink
+;*	 speed, the CAS setting	 is removed from the list of good settings for
+;*	 the DIMM. This is done for both DIMMs and the lists are compared to
+;*	 find the lowest common CAS latency setting. If there are no CAS settings
+;*	 in common we out a ERROR_DIFF_DIMMS (78h) to port 80h and halt.
+;*
+;*	Entry:
+;*	Exit: Set fastest CAS Latency based on GeodeLink speed and SPD information.
+;*	Destroys: We really use everything !
+;*****************************************************************************/
+	uint16_t glspeed;
+	uint8_t spd_byte, casmap0, casmap1;
+	msr_t msr;
+
+	glspeed = GeodeLinkSpeed();
+
+	casmap0 = getcasmap(DIMM0, glspeed);
+	casmap1 = getcasmap(DIMM1, glspeed);
 
 	/*********************	CAS_LAT MAP COMPARE	***************************/
 	if (casmap0 == 0) {
-		spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap1)];
+		spd_byte = CASDDR[__builtin_ctz(casmap1)];
 	} else if (casmap1 == 0) {
-		spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap0)];
+		spd_byte = CASDDR[__builtin_ctz(casmap0)];
 	} else if ((casmap0 &= casmap1)) {
-		spd_byte = CASDDR[__builtin_ctz((uint32_t) casmap0)];
+		spd_byte = CASDDR[__builtin_ctz(casmap0)];
 	} else {
 		print_emerg("DIMM CAS Latencies not compatible\n");
 		post_code(ERROR_DIFF_DIMMS);