[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>
diff --git a/arch/arm/mach-pxa/Makefile b/arch/arm/mach-pxa/Makefile
index c4e6d25..efc2f65 100644
--- a/arch/arm/mach-pxa/Makefile
+++ b/arch/arm/mach-pxa/Makefile
@@ -24,3 +24,7 @@
# Misc features
obj-$(CONFIG_PM) += pm.o sleep.o
+
+ifeq ($(CONFIG_PXA27x),y)
+obj-$(CONFIG_PM) += standby.o
+endif
diff --git a/arch/arm/mach-pxa/pxa27x.c b/arch/arm/mach-pxa/pxa27x.c
index 893964f..9a791b0 100644
--- a/arch/arm/mach-pxa/pxa27x.c
+++ b/arch/arm/mach-pxa/pxa27x.c
@@ -126,6 +126,7 @@
{
switch (state) {
case PM_SUSPEND_MEM:
+ case PM_SUSPEND_STANDBY:
return 0;
default:
return -EINVAL;
@@ -138,7 +139,10 @@
extern void pxa_cpu_suspend(unsigned int);
extern void pxa_cpu_resume(void);
- CKEN = CKEN22_MEMC | CKEN9_OSTIMER;
+ if (state == PM_SUSPEND_STANDBY)
+ CKEN = CKEN22_MEMC | CKEN9_OSTIMER | CKEN16_LCD |CKEN0_PWM0;
+ else
+ CKEN = CKEN22_MEMC | CKEN9_OSTIMER;
/* ensure voltage-change sequencer not initiated, which hangs */
PCFR &= ~PCFR_FVC;
@@ -147,6 +151,9 @@
PEDR = 0xDF12FE1B;
switch (state) {
+ case PM_SUSPEND_STANDBY:
+ pxa_cpu_standby();
+ break;
case PM_SUSPEND_MEM:
/* set resume return address */
PSPR = virt_to_phys(pxa_cpu_resume);
diff --git a/arch/arm/mach-pxa/standby.S b/arch/arm/mach-pxa/standby.S
new file mode 100644
index 0000000..8a3f27b
--- /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