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
diff --git a/CHANGELOG b/CHANGELOG
index 5480a69..547f90c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,12 @@
Changes since U-Boot 1.1.4:
======================================================================
+* 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
+
* Update PK1C20 board
-Update base addresses for standard configuration
-Eliminate use of CACHE_BYPASS in board code
diff --git a/cpu/nios2/epcs.c b/cpu/nios2/epcs.c
index fd9fd84..414c38c 100644
--- a/cpu/nios2/epcs.c
+++ b/cpu/nios2/epcs.c
@@ -210,6 +210,21 @@
{ 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];
diff --git a/include/nios2-epcs.h b/include/nios2-epcs.h
index 2c9522c..20e0c87 100644
--- a/include/nios2-epcs.h
+++ b/include/nios2-epcs.h
@@ -38,6 +38,11 @@
unsigned char prot_mask; /* Protection mask */
}epcs_devinfo_t;
+/* Resets the epcs controller -- to prevent (potential) soft-reset
+ * problems when booting from the epcs controller
+ */
+extern int epcs_reset (void);
+
/* Returns the devinfo struct if EPCS device is found;
* NULL otherwise.
*/
diff --git a/lib_nios2/board.c b/lib_nios2/board.c
index cd23037..7ffb3f0 100644
--- a/lib_nios2/board.c
+++ b/lib_nios2/board.c
@@ -31,6 +31,9 @@
#ifdef CONFIG_STATUS_LED
#include <status_led.h>
#endif
+#if defined(CFG_NIOS_EPCSBASE)
+#include <nios2-epcs.h>
+#endif
DECLARE_GLOBAL_DATA_PTR;
@@ -93,6 +96,9 @@
#if defined(CONFIG_BOARD_EARLY_INIT_F)
board_early_init_f, /* Call board-specific init code early.*/
#endif
+#if defined(CFG_NIOS_EPCSBASE)
+ epcs_reset,
+#endif
env_init,
serial_init,
@@ -165,6 +171,10 @@
WATCHDOG_RESET ();
interrupt_init ();
+#if defined(CONFIG_BOARD_LATE_INIT)
+ board_late_init ();
+#endif
+
/* main_loop */
for (;;) {
WATCHDOG_RESET ();
