ppc4xx: Enable overwriting of default scan window for IBM DDR2 controller

This patch makes it possible to overwrite the default auto-calibration
scan window (SDRAM_WRDTR.[WDTR], SDRAM_CLKTR.[CKTR] values) with
board specific values. The parameters of the weak default function are
corrected as well. This way we don't need the casts any more.

This feature will be used by an upcoming PPC460GT board port.

Signed-off-by: Stefan Roese <sr@denx.de>

arch/powerpc/cpu/ppc4xx/4xx_ibm_ddr2_autocalib.c

@@ -83,11 +83,6 @@ struct ddrautocal {
 	u32 flags;
 };
 
-struct sdram_timing {
-	u32 wrdtr;
-	u32 clktr;
-};
-
 struct sdram_timing_clks {
 	u32 wrdtr;
 	u32 clktr;
@@ -145,11 +140,12 @@ void
 spd_ddr_init_hang(void) __attribute__((weak, alias("__spd_ddr_init_hang")));
 #endif /* defined(CONFIG_SPD_EEPROM) */
 
-ulong __ddr_scan_option(ulong default_val)
+struct sdram_timing *__ddr_scan_option(struct sdram_timing *default_val)
 {
 	return default_val;
 }
-ulong ddr_scan_option(ulong) __attribute__((weak, alias("__ddr_scan_option")));
+struct sdram_timing *ddr_scan_option(struct sdram_timing *)
+	__attribute__((weak, alias("__ddr_scan_option")));
 
 u32 __ddr_rdss_opt(u32 default_val)
 {
@@ -931,7 +927,7 @@ static u32 DQS_calibration_methodB(struct ddrautocal *cal)
  * known working {SDRAM_WRDTR.[WDTR], SDRAM_CLKTR.[CKTR]} value
  * pairs via a board defined ddr_scan_option() function.
  */
-struct sdram_timing full_scan_options[] = {
+static struct sdram_timing full_scan_options[] = {
 	{0, 0}, {0, 1}, {0, 2}, {0, 3},
 	{1, 0}, {1, 1}, {1, 2}, {1, 3},
 	{2, 0}, {2, 1}, {2, 2}, {2, 3},
@@ -970,10 +966,7 @@ u32 DQS_autocalibration(void)
 
 	memset(&tcal, 0, sizeof(tcal));
 
-	ddr_scan_option((ulong)full_scan_options);
-
-	scan_list =
-	      (struct sdram_timing *)ddr_scan_option((ulong)full_scan_options);
+	scan_list = ddr_scan_option(full_scan_options);
 
 	mfsdram(SDRAM_MCOPT1, val);
 	if ((val & SDRAM_MCOPT1_MCHK_CHK_REP) == SDRAM_MCOPT1_MCHK_CHK_REP)

arch/powerpc/include/asm/ppc4xx-sdram.h

@@ -1394,6 +1394,11 @@
 #endif /* CONFIG_SDRAM_PPC4xx_DENALI_DDR2 */
 
 #ifndef __ASSEMBLY__
+struct sdram_timing {
+	u32 wrdtr;
+	u32 clktr;
+};
+
 /*
  * Prototypes
  */