ARM: mxs: add initial pm support

This is a very initial pm support and basically does nothing.
With this pm support entry, drivers can start testing their own
pm functions.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mxs/Makefile

@@ -2,6 +2,7 @@
 obj-y := clock.o devices.o gpio.o icoll.o iomux.o system.o timer.o
 
 obj-$(CONFIG_MXS_OCOTP) += ocotp.o
+obj-$(CONFIG_PM) += pm.o
 
 obj-$(CONFIG_SOC_IMX23) += clock-mx23.o mm-mx23.o
 obj-$(CONFIG_SOC_IMX28) += clock-mx28.o mm-mx28.o

arch/arm/mach-mxs/pm.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2010 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 as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/io.h>
+#include <mach/system.h>
+
+static int mxs_suspend_enter(suspend_state_t state)
+{
+	switch (state) {
+	case PM_SUSPEND_MEM:
+		arch_idle();
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct platform_suspend_ops mxs_suspend_ops = {
+	.enter = mxs_suspend_enter,
+	.valid = suspend_valid_only_mem,
+};
+
+static int __init mxs_pm_init(void)
+{
+	suspend_set_ops(&mxs_suspend_ops);
+	return 0;
+}
+device_initcall(mxs_pm_init);