1 files changed, 82 insertions, 0 deletions

diff --git a/arch/powerpc/boot/mpc8xx.c b/arch/powerpc/boot/mpc8xx.c
new file mode 100644
index 000000000000..add55a7f184f
--- /dev/null
+++ b/arch/powerpc/boot/mpc8xx.c
@@ -0,0 +1,82 @@
+/*
+ * MPC8xx support functions
+ *
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * Copyright (c) 2007 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 version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include "ops.h"
+#include "types.h"
+#include "fsl-soc.h"
+#include "mpc8xx.h"
+#include "stdio.h"
+#include "io.h"
+
+#define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */
+
+/* Return system clock from crystal frequency */
+u32 mpc885_get_clock(u32 crystal)
+{
+        u32 *immr;
+        u32 plprcr;
+        int mfi, mfn, mfd, pdf, div;
+        u32 ret;
+
+        immr = fsl_get_immr();
+        if (!immr) {
+                printf("mpc885_get_clock: Couldn't get IMMR base.\r\n");
+                return 0;
+        }
+
+        plprcr = in_be32(&immr[MPC8XX_PLPRCR]);
+
+        mfi = (plprcr >> 16) & 15;
+        if (mfi < 5) {
+                printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n",
+                       mfi);
+                mfi = 5;
+        }
+
+        pdf = (plprcr >> 1) & 0xf;
+        div = (plprcr >> 20) & 3;
+        mfd = (plprcr >> 22) & 0x1f;
+        mfn = (plprcr >> 27) & 0x1f;
+
+        ret = crystal * mfi;
+
+        if (mfn != 0)
+                ret += crystal * mfn / (mfd + 1);
+
+        return ret / (pdf + 1);
+}
+
+/* Set common device tree fields based on the given clock frequencies. */
+void mpc8xx_set_clocks(u32 sysclk)
+{
+        void *node;
+
+        dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk);
+
+        node = finddevice("/soc/cpm");
+        if (node)
+                setprop(node, "clock-frequency", &sysclk, 4);
+
+        node = finddevice("/soc/cpm/brg");
+        if (node)
+                setprop(node, "clock-frequency", &sysclk, 4);
+}
+
+int mpc885_fixup_clocks(u32 crystal)
+{
+        u32 sysclk = mpc885_get_clock(crystal);
+        if (!sysclk)
+                return 0;
+
+        mpc8xx_set_clocks(sysclk);
+        return 1;
+}