i.MX: Add code to emulate i.MX7 SNVS IP-block

Add code to emulate SNVS IP-block. Currently only the bits needed to
be able to emulate machine shutdown are implemented.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Marcel Apfelbaum <marcel.apfelbaum@zoho.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-devel@nongnu.org
Cc: qemu-arm@nongnu.org
Cc: yurovsky@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

include/hw/misc/imx7_snvs.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2017, Impinj, Inc.
+ *
+ * i.MX7 SNVS block emulation code
+ *
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef IMX7_SNVS_H
+#define IMX7_SNVS_H
+
+#include "qemu/bitops.h"
+#include "hw/sysbus.h"
+
+
+enum IMX7SNVSRegisters {
+    SNVS_LPCR = 0x38,
+    SNVS_LPCR_TOP   = BIT(6),
+    SNVS_LPCR_DP_EN = BIT(5)
+};
+
+#define TYPE_IMX7_SNVS "imx7.snvs"
+#define IMX7_SNVS(obj) OBJECT_CHECK(IMX7SNVSState, (obj), TYPE_IMX7_SNVS)
+
+typedef struct IMX7SNVSState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    MemoryRegion mmio;
+} IMX7SNVSState;
+
+#endif /* IMX7_SNVS_H */