v4.19.13 snapshot.
diff --git a/arch/arm/mach-imx/cpu-imx25.c b/arch/arm/mach-imx/cpu-imx25.c
new file mode 100644
index 0000000..d0ad67e
--- /dev/null
+++ b/arch/arm/mach-imx/cpu-imx25.c
@@ -0,0 +1,51 @@
+/*
+ * MX25 CPU type detection
+ *
+ * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "iim.h"
+#include "hardware.h"
+
+static int mx25_cpu_rev = -1;
+
+static int mx25_read_cpu_rev(void)
+{
+ u32 rev;
+ void __iomem *iim_base;
+ struct device_node *np;
+
+ np = of_find_compatible_node(NULL, NULL, "fsl,imx25-iim");
+ iim_base = of_iomap(np, 0);
+ BUG_ON(!iim_base);
+ rev = readl(iim_base + MXC_IIMSREV);
+ iounmap(iim_base);
+
+ switch (rev) {
+ case 0x00:
+ return IMX_CHIP_REVISION_1_0;
+ case 0x01:
+ return IMX_CHIP_REVISION_1_1;
+ default:
+ return IMX_CHIP_REVISION_UNKNOWN;
+ }
+}
+
+int mx25_revision(void)
+{
+ if (mx25_cpu_rev == -1)
+ mx25_cpu_rev = mx25_read_cpu_rev();
+
+ return mx25_cpu_rev;
+}
+EXPORT_SYMBOL(mx25_revision);