ARM: mx25: Add basic suspend/resume support

Tested basic suspend/resume on a mx25pdk:

$ echo enabled > /sys/class/tty/ttymxc0/power/wakeup
$ echo mem > /sys/power/state

Then press any key in the serial console and the system wakes up.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/pm-imx25.c b/arch/arm/mach-imx/pm-imx25.c
new file mode 100644
index 000000000000..8bba9fcd96f6
--- /dev/null
+++ b/arch/arm/mach-imx/pm-imx25.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2016 NXP Semiconductors
+ *
+ * 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 <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/io.h>
+
+static int imx25_suspend_enter(suspend_state_t state)
+{
+	if (!IS_ENABLED(CONFIG_PM))
+		return 0;
+
+	switch (state) {
+	case PM_SUSPEND_MEM:
+		cpu_do_idle();
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct platform_suspend_ops imx25_suspend_ops = {
+	.enter = imx25_suspend_enter,
+	.valid = suspend_valid_only_mem,
+};
+
+void __init imx25_pm_init(void)
+{
+	suspend_set_ops(&imx25_suspend_ops);
+}