[PATCH] ARM: 2781/2: PXA27x Standby mode take 2

Patch from Todd Poynor

Add support for PXA27x Standby mode, a low-power mode that retains CPU
and some peripheral state (the existing "sleep" mode is a power-power
mode that retains less state). Activated via:
echo -n standby > /sys/power/state
From: David Burrage and Todd Poynor

Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 32 insertions, 0 deletions

diff --git a/arch/arm/mach-pxa/standby.S b/arch/arm/mach-pxa/standby.S
new file mode 100644
index 000000000000..8a3f27b76784
--- /dev/null
+++ b/arch/arm/mach-pxa/standby.S
@@ -0,0 +1,32 @@
+/*
+ * PXA27x standby mode
+ *
+ * Author: David Burrage
+ *
+ * 2005 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/hardware.h>
+
+#include <asm/arch/pxa-regs.h>
+
+                .text
+
+ENTRY(pxa_cpu_standby)
+        ldr     r0, =PSSR
+        mov     r1, #(PSSR_PH | PSSR_STS)
+        mov     r2, #2
+        mov     r3, #UNCACHED_PHYS_0    @ Read mem context in.
+        ldr     ip, [r3]
+        b       1f
+
+        .align  5
+1:      mcr     p14, 0, r2, c7, c0, 0   @ put the system into Standby
+        str     r1, [r0]                @ make sure PSSR_PH/STS are clear
+        mov     pc, lr