Nios II - Add EPCS Controller bootrom work-around

  -When booting from an epcs controller, the epcs bootrom may leave the
  slave select in an asserted state causing soft reset hang. This
  patch ensures slave select is negated at reset.
  Patch by Scott McNutt, 08 Jun 2006

1 files changed, 15 insertions, 0 deletions

diff --git a/cpu/nios2/epcs.c b/cpu/nios2/epcs.c
index fd9fd8498a..414c38c2b1 100644
--- a/cpu/nios2/epcs.c
+++ b/cpu/nios2/epcs.c
@@ -210,6 +210,21 @@ static struct epcs_devinfo_t devinfo[] = {
 	{ 0, 0, 0, 0, 0, 0 }
 };
 
+int epcs_reset (void)
+{
+	/* When booting from an epcs controller, the epcs bootrom
+	 * code may leave the slave select in an asserted state.
+	 * This causes two problems: (1) The initial epcs access
+	 * will fail -- not a big deal, and (2) a software reset
+	 * will cause the bootrom code to hang since it does not
+	 * ensure the select is negated prior to first access -- a
+	 * big deal. Here we just negate chip select and everything
+	 * gets better :-)
+	 */
+	epcs_cs (0); /* Negate chip select */
+	return (0);
+}
+
 epcs_devinfo_t *epcs_dev_find (void)
 {
 	unsigned char buf[4];