[POWERPC] Add 6xx-style HID0_SLEEP support.

This adds a function to put a 6xx/7xx/7xxx/83xx family CPU into sleep
mode, and return after an interrupt has occurred.  It expects to be
called with interrupts disabled, and returns with interrupts disabled.
Interrupts are enabled while the processor is asleep, but the interrupt
that wakes the processor is not handled; it is still pending when this
function returns.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/6xx-suspend.S b/arch/powerpc/sysdev/6xx-suspend.S
new file mode 100644
index 000000000000..21cda085d926
--- /dev/null
+++ b/arch/powerpc/sysdev/6xx-suspend.S
@@ -0,0 +1,52 @@
+/*
+ * Enter and leave sleep state on chips with 6xx-style HID0
+ * power management bits, which don't leave sleep state via reset.
+ *
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+
+_GLOBAL(mpc6xx_enter_standby)
+        mflr    r4
+
+        mfspr   r5, SPRN_HID0
+        rlwinm  r5, r5, 0, ~(HID0_DOZE | HID0_NAP)
+        oris    r5, r5, HID0_SLEEP@h
+        mtspr   SPRN_HID0, r5
+        isync
+
+        lis     r5, ret_from_standby@h
+        ori     r5, r5, ret_from_standby@l
+        mtlr    r5
+
+        rlwinm  r5, r1, 0, 0, 31-THREAD_SHIFT
+        lwz     r6, TI_LOCAL_FLAGS(r5)
+        ori     r6, r6, _TLF_SLEEPING
+        stw     r6, TI_LOCAL_FLAGS(r5)
+
+        mfmsr   r5
+        ori     r5, r5, MSR_EE
+        oris    r5, r5, MSR_POW@h
+        sync
+        mtmsr   r5
+        isync
+
+1:      b       1b
+
+ret_from_standby:
+        mfspr   r5, SPRN_HID0
+        rlwinm  r5, r5, 0, ~HID0_SLEEP
+        mtspr   SPRN_HID0, r5
+
+        mtlr    r4
+        blr