Blackfin: unify cpu and boot modes

All of the duplicated code for Blackfin processors and boot modes have been
unified.  After all, the core is the same for all processors, just the
peripheral set differs (which gets handled in the drivers).

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 96 insertions, 0 deletions

diff --git a/cpu/blackfin/reset.c b/cpu/blackfin/reset.c
new file mode 100644
index 0000000..d1e34b3
--- /dev/null
+++ b/cpu/blackfin/reset.c
@@ -0,0 +1,96 @@
+/*
+ * reset.c - logic for resetting the cpu
+ *
+ * Copyright (c) 2005-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/blackfin.h>
+#include "cpu.h"
+
+/* A system soft reset makes external memory unusable so force
+ * this function into L1.  We use the compiler ssync here rather
+ * than SSYNC() because it's safe (no interrupts and such) and
+ * we save some L1.  We do not need to force sanity in the SYSCR
+ * register as the BMODE selection bit is cleared by the soft
+ * reset while the Core B bit (on dual core parts) is cleared by
+ * the core reset.
+ */
+__attribute__ ((__l1_text__, __noreturn__))
+void bfin_reset(void)
+{
+	/* Wait for completion of "system" events such as cache line
+	 * line fills so that we avoid infinite stalls later on as
+	 * much as possible.  This code is in L1, so it won't trigger
+	 * any such event after this point in time.
+	 */
+	__builtin_bfin_ssync();
+
+	while (1) {
+		/* 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,
+		 * we'll assume worse case which is a 1:15 ratio.
+		 */
+		asm(
+			"LSETUP (1f, 1f) LC0 = %0\n"
+			"1: nop;"
+			:
+			: "a" (15 * 7)
+			: "LC0", "LB0", "LT0"
+		);
+
+		/* Clear System software reset */
+		bfin_write_SWRST(0);
+
+		/* Wait for the SWRST write to complete.  Cannot rely on SSYNC
+		 * though as the System state is all reset now.
+		 */
+		asm(
+			"LSETUP (1f, 1f) LC1 = %0\n"
+			"1: nop;"
+			:
+			: "a" (15 * 1)
+			: "LC1", "LB1", "LT1"
+		);
+
+		/* Issue core reset */
+		asm("raise 1");
+	}
+}
+
+/* We need to trampoline ourselves up into L1 since our linker
+ * does not have relaxtion support and will only generate a
+ * PC relative call with a 25 bit immediate.  This is not enough
+ * to get us from the top of SDRAM into L1.
+ */
+__attribute__ ((__noreturn__))
+static inline void bfin_reset_trampoline(void)
+{
+	if (board_reset)
+		board_reset();
+	while (1)
+		asm("jump (%0);" : : "a" (bfin_reset));
+}
+
+__attribute__ ((__noreturn__))
+void bfin_reset_or_hang(void)
+{
+#ifdef CONFIG_PANIC_HANG
+	hang();
+#else
+	bfin_reset_trampoline();
+#endif
+}
+
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	bfin_reset_trampoline();
+	return 0;
+}