[U-Boot] [PATCH 31/40] Blackfin: handle new anomalies with reset

[Mike Frysinger]

Workaround fun new anomalies related to software reset of the processor.

Signed-off-by: Mike Frysinger <vapier at gentoo.org>
---
 cpu/blackfin/reset.c |   20 +++++++++++++++-----
 1 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/cpu/blackfin/reset.c b/cpu/blackfin/reset.c
index d1e34b3..284cea5 100644
--- a/cpu/blackfin/reset.c
+++ b/cpu/blackfin/reset.c
@@ -29,26 +29,35 @@ void bfin_reset(void)
 	 */
 	__builtin_bfin_ssync();
 
-	while (1) {
+	/* The bootrom checks to see how it was reset and will
+	 * automatically perform a software reset for us when
+	 * it starts executing after the core reset.
+	 */
+	if (ANOMALY_05000353 || ANOMALY_05000386) {
 		/* Initiate System software reset. */
 		bfin_write_SWRST(0x7);
 
 		/* Due to the way reset is handled in the hardware, we need
-		 * to delay for 7 SCLKS.  The only reliable way to do this is
-		 * to calculate the CCLK/SCLK ratio and multiply 7.  For now,
+		 * to delay for 10 SCLKS.  The only reliable way to do this is
+		 * to calculate the CCLK/SCLK ratio and multiply 10.  For now,
 		 * we'll assume worse case which is a 1:15 ratio.
 		 */
 		asm(
 			"LSETUP (1f, 1f) LC0 = %0\n"
 			"1: nop;"
 			:
-			: "a" (15 * 7)
+			: "a" (15 * 10)
 			: "LC0", "LB0", "LT0"
 		);
 
 		/* Clear System software reset */
 		bfin_write_SWRST(0);
 
+		/* The BF526 ROM will crash during reset */
+#if defined(__ADSPBF522__) || defined(__ADSPBF524__) || defined(__ADSPBF526__)
+		bfin_read_SWRST();
+#endif
+
 		/* Wait for the SWRST write to complete.  Cannot rely on SSYNC
 		 * though as the System state is all reset now.
 		 */
@@ -59,10 +68,11 @@ void bfin_reset(void)
 			: "a" (15 * 1)
 			: "LC1", "LB1", "LT1"
 		);
+	}
 
+	while (1)
 		/* Issue core reset */
 		asm("raise 1");
-	}
 }
 
 /* We need to trampoline ourselves up into L1 since our linker
-- 
1.6.1