Blackfin arch: Fix Bug - Kernel does not boot if re-program clocks

On BF561 EBIU_SDGCTL bit 31 controls the SDRAM external data
path width, typically set 0 for a 32-bit bus width. On other
Blackfin derivatives this bit should be set by default.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/include/asm/mem_init.h

@@ -115,7 +115,7 @@
 #define mem_SDRRC       (((CONFIG_SCLK_HZ / 1000) * SDRAM_Tref) / SDRAM_NRA) - (SDRAM_tRAS_num + SDRAM_tRP_num)
 
 /* Enable SCLK Out */
-#define mem_SDGCTL        (0x80000000 | SCTLE | SDRAM_CL | SDRAM_tRAS | SDRAM_tRP | SDRAM_tRCD | SDRAM_tWR | PSS)
+#define mem_SDGCTL        (SCTLE | SDRAM_CL | SDRAM_tRAS | SDRAM_tRP | SDRAM_tRCD | SDRAM_tWR | PSS)
 #else
 #define mem_SDRRC 	CONFIG_MEM_SDRRC
 #define mem_SDGCTL	CONFIG_MEM_SDGCTL

arch/blackfin/mach-common/clocks-init.c

@@ -14,6 +14,7 @@
 #include <asm/clocks.h>
 #include <asm/mem_init.h>
 
+#define SDGCTL_WIDTH (1 << 31)	/* SDRAM external data path width */
 #define PLL_CTL_VAL \
 	(((CONFIG_VCO_MULT & 63) << 9) | CLKIN_HALF | \
 	 (PLL_BYPASS << 8) | (ANOMALY_05000265 ? 0x8000 : 0))
@@ -76,7 +77,7 @@ void init_clocks(void)
 	bfin_write_PLL_DIV(CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
 #ifdef EBIU_SDGCTL
 	bfin_write_EBIU_SDRRC(mem_SDRRC);
-	bfin_write_EBIU_SDGCTL(mem_SDGCTL);
+	bfin_write_EBIU_SDGCTL((bfin_read_EBIU_SDGCTL() & SDGCTL_WIDTH) | mem_SDGCTL);
 #else
 	bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() & ~(SRREQ));
 	do_sync();