1 files changed, 109 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/sparc/shared/amba/ambapp_freq.c b/c/src/lib/libbsp/sparc/shared/amba/ambapp_freq.c
new file mode 100644
index 0000000000..03c0f68303
--- /dev/null
+++ b/c/src/lib/libbsp/sparc/shared/amba/ambapp_freq.c
@@ -0,0 +1,109 @@
+/*
+ *  AMBA Plug & Play routines
+ *
+ *  COPYRIGHT (c) 2011
+ *  Aeroflex Gaisler
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+
+#include <ambapp.h>
+
+/* Calculate AHB Bus frequency of
+ *   - Bus[0] (inverse=1), relative to the frequency of Bus[ahbidx]
+ *     NOTE: set freq_hz to frequency of Bus[ahbidx].
+ *   or
+ *   - Bus[ahbidx] (inverse=0), relative to the frequency of Bus[0]
+ *     NOTE: set freq_hz to frequency of Bus[0].
+ *
+ * If a unsupported bridge is found the invalid frequncy of 0Hz is
+ * returned.
+ */
+unsigned int ambapp_freq_calc(
+  struct ambapp_bus *abus,
+  int ahbidx,
+  unsigned int freq_hz,
+  int inverse)
+{
+  struct ambapp_ahb_info *ahb;
+  struct ambapp_dev *bridge;
+  unsigned char ffact;
+  int dir;
+
+  /* Found Bus0? */
+  bridge = abus->ahbs[ahbidx].bridge;
+  if (!bridge)
+    return freq_hz;
+
+  /* Find this bus frequency relative to freq_hz */
+  if ((bridge->vendor == VENDOR_GAISLER) &&
+      ((bridge->device == GAISLER_AHB2AHB) ||
+      (bridge->device == GAISLER_L2CACHE))) {
+    ahb = DEV_TO_AHB(bridge);
+    ffact = (ahb->custom[0] & AMBAPP_FLAG_FFACT) >> 4;
+    if (ffact != 0) {
+      dir = ahb->custom[0] & AMBAPP_FLAG_FFACT_DIR;
+
+      /* Calculate frequency by dividing or
+       * multiplying system frequency
+       */
+      if ((dir && !inverse) || (!dir && inverse))
+        freq_hz = freq_hz * ffact;
+      else
+        freq_hz = freq_hz / ffact;
+    }
+    return ambapp_freq_calc(abus, ahb->ahbidx, freq_hz, inverse);
+  } else {
+    /* Unknown bridge, impossible to calc frequency */
+    return 0;
+  }
+}
+
+/* Find the frequency of all AHB Buses from knowing the frequency of one
+ * particular APB/AHB Device.
+ */
+void ambapp_freq_init(
+  struct ambapp_bus *abus,
+  struct ambapp_dev *dev,
+  unsigned int freq_hz)
+{
+  struct ambapp_common_info *info;
+  int i;
+
+  for (i=0; i<AHB_BUS_MAX; i++)
+    abus->ahbs[i].freq_hz = 0;
+
+  /* Register Frequency at the AHB bus that the device the user gave us
+   * is located at.
+   */
+  if (dev) {
+    info = DEV_TO_COMMON(dev);
+    abus->ahbs[info->ahbidx].freq_hz = freq_hz;
+
+    /* Find Frequency of Bus 0 */
+    abus->ahbs[0].freq_hz = ambapp_freq_calc(abus, info->ahbidx, freq_hz, 1);
+  } else {
+    abus->ahbs[0].freq_hz = freq_hz;
+  }
+
+  /* Find Frequency of all except for Bus0 and the bus which frequency
+   * was reported at
+   */
+  for (i=1; i<AHB_BUS_MAX; i++) {
+    if (abus->ahbs[i].ioarea == 0)
+      break;
+    if (abus->ahbs[i].freq_hz != 0)
+      continue;
+    abus->ahbs[i].freq_hz = ambapp_freq_calc(abus, i, abus->ahbs[0].freq_hz, 0);
+  }
+}
+
+/* Assign a AMBA Bus a frequency but reporting the frequency of a
+ * particular AHB/APB device */
+unsigned int ambapp_freq_get(struct ambapp_bus *abus, struct ambapp_dev *dev)
+{
+  struct ambapp_common_info *info = DEV_TO_COMMON(dev);
+  return abus->ahbs[info->ahbidx].freq_hz;
+}