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authorMichael Hennerich <michael.hennerich@analog.com>2008-01-22 13:38:02 +0300
committerBryan Wu <bryan.wu@analog.com>2008-01-22 13:38:02 +0300
commit444ad82bc3eaa554be40d22dc248e58aeefd54d9 (patch)
tree3244f4f4585847419dc28c706aec658cba6e05be /arch/blackfin
parenta628a8bcd8a6daea6096fe781fc36cae4ac1ed48 (diff)
downloadlinux-444ad82bc3eaa554be40d22dc248e58aeefd54d9.tar.xz
[Blackfin] arch: Add proper SW System Reset delay sequence
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/kernel/reboot.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/blackfin/kernel/reboot.c b/arch/blackfin/kernel/reboot.c
index 06501a594dda..483f93dfc1b5 100644
--- a/arch/blackfin/kernel/reboot.c
+++ b/arch/blackfin/kernel/reboot.c
@@ -19,6 +19,11 @@
#define SYSCR_VAL 0x10
#endif
+/*
+ * Delay min 5 SCLK cycles using worst case CCLK/SCLK ratio (15)
+ */
+#define SWRST_DELAY (5 * 15)
+
/* A system soft reset makes external memory unusable
* so force this function into L1.
*/
@@ -34,11 +39,15 @@ void bfin_reset(void)
while (1) {
/* initiate system soft reset with magic 0x7 */
bfin_write_SWRST(0x7);
- bfin_read_SWRST();
- asm("ssync;");
+
+ /* Wait for System reset to actually reset, needs to be 5 SCLKs, */
+ /* Assume CCLK / SCLK ratio is worst case (15), and use 5*15 */
+
+ asm("LSETUP(.Lfoo,.Lfoo) LC0 = %0\n .Lfoo: NOP;\n"
+ : : "a" (SWRST_DELAY) : "LC0", "LT0", "LB0");
+
/* clear system soft reset */
bfin_write_SWRST(0);
- bfin_read_SWRST();
asm("ssync;");
/* issue core reset */
asm("raise 1");