1 files changed, 121 insertions, 0 deletions
diff --git a/firmware/usrp2/lib/clocks.c b/firmware/usrp2/lib/clocks.c
new file mode 100644
index 000000000..bc1954e13
--- /dev/null
+++ b/firmware/usrp2/lib/clocks.c
@@ -0,0 +1,121 @@
+//
+// Copyright 2010-2011 Ettus Research LLC
+//
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ *
+ * 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <clocks.h>
+#include <stdbool.h>
+#include "memory_map.h"
+#include "ad9510.h"
+#include "spi.h"
+
+/*!
+ * \brief Lock Detect -- Return True if our PLL is locked
+ */
+bool clocks_lock_detect();
+
+/*!
+ * \brief Enable or disable fpga clock.  Disabling would wedge and require a power cycle.
+ */
+void clocks_enable_fpga_clk(bool enable, int divisor);
+
+void 
+clocks_init(void)
+{
+  // Set up basic clocking functions in AD9510
+  ad9510_write_reg(0x45, 0x01);
+
+  //enable the 100MHz clock output to the FPGA for 50MHz CPU clock
+  clocks_enable_fpga_clk(true, 1);
+
+  //! Cannot SPI wait since SPI is on DSP clock
+  //! because DSP clock goes away until DCM reset.
+  //! However, spi is quick, the cpu is slow, its already ready...
+  //spi_wait();
+
+  //wait for the clock to stabilize
+  while(!clocks_lock_detect());
+
+  //issue a reset to the DCM so it locks up to the new freq
+  output_regs->clk_ctrl |= CLK_RESET;
+}
+
+bool 
+clocks_lock_detect()
+{
+    return (pic_regs->pending & PIC_CLKSTATUS);
+}
+
+int inline
+clocks_gen_div(int divisor)
+{
+  int L,H;
+  L = (divisor>>1)-1;
+  H = divisor-L-2;
+  return (L<<4)|H;
+}
+
+#define CLOCK_OUT_EN 0x08
+#define CLOCK_OUT_DIS_CMOS 0x01
+#define CLOCK_OUT_DIS_PECL 0x02
+#define CLOCK_DIV_DIS 0x80
+#define CLOCK_DIV_EN 0x00
+
+#define CLOCK_MODE_PECL 1
+#define CLOCK_MODE_LVDS 2
+#define CLOCK_MODE_CMOS 3
+
+//CHANGED: set to PECL for default behavior
+void 
+clocks_enable_XXX_clk(bool enable, int divisor, int reg_en, int reg_div, int mode)
+{
+  int enable_word, div_word, div_en_word;
+
+  switch(mode) {
+  case CLOCK_MODE_LVDS :
+    enable_word = enable ? 0x02 : 0x03;
+    break;
+  case CLOCK_MODE_CMOS :
+    enable_word = enable ? 0x08 : 0x09;
+    break;
+  case CLOCK_MODE_PECL :
+	default:
+    enable_word = enable ? 0x08 : 0x0A;
+    break;
+  }
+  if(enable && (divisor>1)) {
+    div_word = clocks_gen_div(divisor);
+    div_en_word = CLOCK_DIV_EN;
+  }
+  else {
+    div_word = 0;
+    div_en_word = CLOCK_DIV_DIS;
+  }
+
+  ad9510_write_reg(reg_en,enable_word); // Output en/dis
+  ad9510_write_reg(reg_div,div_word); // Set divisor
+  ad9510_write_reg(reg_div+1,div_en_word); // Enable or Bypass Divider
+  ad9510_write_reg(0x5A, 0x01);  // Update Regs
+}
+
+// Clock 1
+void
+clocks_enable_fpga_clk(bool enable, int divisor)
+{
+  clocks_enable_XXX_clk(enable,divisor,0x3D,0x4A,CLOCK_MODE_PECL);
+}