i.MX27: add suspend to RAM support

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 47 insertions, 1 deletions

diff --git a/arch/arm/mach-mx2/Makefile b/arch/arm/mach-mx2/Makefile
index e3254faac828..27d496c3e5cb 100644
--- a/arch/arm/mach-mx2/Makefile
+++ b/arch/arm/mach-mx2/Makefile
@@ -8,7 +8,7 @@ obj-y	:=  devices.o serial.o
 
 obj-$(CONFIG_MACH_MX21) += clock_imx21.o mm-imx21.o
 
-obj-$(CONFIG_MACH_MX27) += cpu_imx27.o
+obj-$(CONFIG_MACH_MX27) += cpu_imx27.o pm-imx27.o
 obj-$(CONFIG_MACH_MX27) += clock_imx27.o mm-imx27.o
 
 obj-$(CONFIG_MACH_MX21ADS) += mach-mx21ads.o
diff --git a/arch/arm/mach-mx2/pm-imx27.c b/arch/arm/mach-mx2/pm-imx27.c
new file mode 100644
index 000000000000..afc17ce0bb54
--- /dev/null
+++ b/arch/arm/mach-mx2/pm-imx27.c
@@ -0,0 +1,46 @@
+/*
+ * i.MX27 Power Management Routines
+ *
+ * Based on Freescale's BSP
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/io.h>
+#include <mach/system.h>
+#include <mach/mx27.h>
+
+static int mx27_suspend_enter(suspend_state_t state)
+{
+        u32 cscr;
+        switch (state) {
+        case PM_SUSPEND_MEM:
+                /* Clear MPEN and SPEN to disable MPLL/SPLL */
+                cscr = __raw_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
+                cscr &= 0xFFFFFFFC;
+                __raw_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
+                /* Executes WFI */
+                arch_idle();
+                break;
+
+        default:
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static struct platform_suspend_ops mx27_suspend_ops = {
+        .enter = mx27_suspend_enter,
+        .valid = suspend_valid_only_mem,
+};
+
+static int __init mx27_pm_init(void)
+{
+        suspend_set_ops(&mx27_suspend_ops);
+        return 0;
+}
+
+device_initcall(mx27_pm_init);