ppc4xx: Add CONFIG_4xx_DCACHE compile options to enable cached SDRAM

This patch adds the CONFIG_4xx_DCACHE options to some SDRAM init files
and to the Sequoia TLB init code. Now the cache can be enabled on 44x
boards by defining CONFIG_4xx_DCACHE in the board config file. This
option will disappear, when more boards use is successfully and no
more known problems exist.

This is tested successfully on Sequoia and Katmai. The only problem that
needs to be fixed is, that USB is not working on Sequoia right now, since
it will need some cache handling code too, similar to the 4xx EMAC driver.

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

board/amcc/sequoia/init.S

@@ -98,7 +98,11 @@ tlbtab:
 #endif
 
 	/* TLB-entry for DDR SDRAM (Up to 2GB) */
+#ifdef CONFIG_4xx_DCACHE
+	tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G)
+#else
 	tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G|SA_I )
+#endif
 
 #ifdef CFG_INIT_RAM_DCACHE
 	/* TLB-entry for init-ram in dcache (SA_I must be turned off!) */

cpu/ppc4xx/44x_spd_ddr.c

@@ -251,10 +251,10 @@ void spd_ddr_init_hang (void) __attribute__((weak, alias("__spd_ddr_init_hang"))
  * memory.
  *
  * If at some time this restriction doesn't apply anymore, just define
- * CFG_ENABLE_SDRAM_CACHE in the board config file and this code should setup
+ * CONFIG_4xx_DCACHE in the board config file and this code should setup
  * everything correctly.
  */
-#ifdef CFG_ENABLE_SDRAM_CACHE
+#ifdef CONFIG_4xx_DCACHE
 #define MY_TLB_WORD2_I_ENABLE	0			/* enable caching on SDRAM */
 #else
 #define MY_TLB_WORD2_I_ENABLE	TLB_WORD2_I_ENABLE	/* disable caching on SDRAM */
@@ -345,7 +345,7 @@ long int spd_sdram(void) {
 	 */
 	check_volt_type(dimm_populated, iic0_dimm_addr, num_dimm_banks);
 
-#if defined(CONFIG_440GX) || defined(CONFIG_440EP) || defined(CONFIG_440GR) || defined(CONFIG_440SP)
+#if defined(CONFIG_440GX) || defined(CONFIG_440EP) || defined(CONFIG_440GR)
 	/*
 	 * Soft-reset SDRAM controller.
 	 */
@@ -1197,9 +1197,6 @@ static void program_tr1(void)
 	}
 
 	rdclt_average = ((max_start + max_end) >> 1);
-	if (rdclt_average >= 0x60)
-		while (1)
-			;
 
 	if (rdclt_average < 0) {
 		rdclt_average = 0;

cpu/ppc4xx/44x_spd_ddr2.c

@@ -120,10 +120,10 @@
  * memory.
  *
  * If at some time this restriction doesn't apply anymore, just define
- * CFG_ENABLE_SDRAM_CACHE in the board config file and this code should setup
+ * CONFIG_4xx_DCACHE in the board config file and this code should setup
  * everything correctly.
  */
-#ifdef CFG_ENABLE_SDRAM_CACHE
+#ifdef CONFIG_4xx_DCACHE
 #define MY_TLB_WORD2_I_ENABLE	0			/* enable caching on SDRAM */
 #else
 #define MY_TLB_WORD2_I_ENABLE	TLB_WORD2_I_ENABLE	/* disable caching on SDRAM */