ARM: shmobile: sh73a0: Add CPU sleep suspend

Add the lighest possible sleep mode on Cortex-A9 cores: CPU sleep. It is
entered by a simple dsb and wfi instruction via cpu_do_idle(). As just
clocks are stopped there is no need to save or restore any state of the
system.
Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_ARCH_SHMOBILE)	+= pm-rmobile.o
 obj-$(CONFIG_ARCH_SH7372)	+= pm-sh7372.o sleep-sh7372.o
 obj-$(CONFIG_ARCH_R8A7740)	+= pm-r8a7740.o
 obj-$(CONFIG_ARCH_R8A7779)	+= pm-r8a7779.o
+obj-$(CONFIG_ARCH_SH73A0)	+= pm-sh73a0.o
 
 # Board objects
 obj-$(CONFIG_MACH_AP4EVB)	+= board-ap4evb.o

arch/arm/mach-shmobile/board-kzm9g.c

@@ -772,6 +772,8 @@ static void __init kzm_init(void)
 
 	sh73a0_add_standard_devices();
 	platform_add_devices(kzm_devices, ARRAY_SIZE(kzm_devices));
+
+	sh73a0_pm_init();
 }
 
 static void kzm9g_restart(char mode, const char *cmd)

arch/arm/mach-shmobile/include/mach/common.h

@@ -40,6 +40,7 @@ extern void sh73a0_add_early_devices(void);
 extern void sh73a0_add_standard_devices(void);
 extern void sh73a0_clock_init(void);
 extern void sh73a0_pinmux_init(void);
+extern void sh73a0_pm_init(void);
 extern struct clk sh73a0_extal1_clk;
 extern struct clk sh73a0_extal2_clk;
 extern struct clk sh73a0_extcki_clk;

arch/arm/mach-shmobile/pm-sh73a0.c

+/*
+ * sh73a0 Power management support
+ *
+ *  Copyright (C) 2012 Bastian Hecht <hechtb+renesas@gmail.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/suspend.h>
+#include <mach/common.h>
+
+#ifdef CONFIG_SUSPEND
+static int sh73a0_enter_suspend(suspend_state_t suspend_state)
+{
+	cpu_do_idle();
+	return 0;
+}
+
+static void sh73a0_suspend_init(void)
+{
+	shmobile_suspend_ops.enter = sh73a0_enter_suspend;
+}
+#else
+static void sh73a0_suspend_init(void) {}
+#endif
+
+void __init sh73a0_pm_init(void)
+{
+	sh73a0_suspend_init();
+}