1 files changed, 54 insertions, 0 deletions
diff --git a/bsp/drivers/fe300prci/fe300prci_driver.h b/bsp/drivers/fe300prci/fe300prci_driver.h
new file mode 100644
index 0000000..052edcb
--- /dev/null
+++ b/bsp/drivers/fe300prci/fe300prci_driver.h
@@ -0,0 +1,54 @@
+// See LICENSE file for license details
+
+#ifndef _FE300PRCI_DRIVER_H_
+#define _FE300PRCI_DRIVER_H_
+
+#include <unistd.h>
+
+
+/* Measure and return the approximate frequency of the 
+ * CPU, as given by measuring the mcycle counter against 
+ * the mtime ticks.
+ */
+static uint32_t PRCI_measure_mcycle_freq(uint32_t mtime_ticks, uint32_t mtime_freq);
+
+/* Safely switch over to the HFROSC using the given div
+ * and trim settings.
+ */
+static void PRCI_use_hfrosc(int div, int trim);
+
+/* Safely switch over to the PLL using the given
+ * settings.
+ * 
+ * Note that not all combinations of the inputs are actually
+ * legal, and this function does not check for their
+ * legality ("safely" means that this function won't turn off
+ * or glitch the clock the CPU is actually running off, but
+ * doesn't protect against you making it too fast or slow.)
+ */
+
+static void PRCI_use_pll(int refsel, int bypass,
+			 int r, int f, int q, int finaldiv,
+			 int hfroscdiv, int hfrosctrim);
+
+/* Use the default clocks configured at reset.
+ * This is ~16Mhz HFROSC and turns off the LFROSC
+ * (on the current FE310 Dev Platforms, an external LFROSC is 
+ * used as it is more power efficient).
+ */
+static void PRCI_use_default_clocks();
+
+/* This routine will adjust the HFROSC trim
+ * as the PLL clock source, measure the resulting
+ * frequency, and attempt to get close to the requested
+ * frequency. It returns the actual measured frequency. 
+ *
+ * Note that the requested frequency must be within the 
+ * range supported by the PLL so not all values are 
+ * achievable with this function, and not all 
+ * are guaranteed to actually work.
+ */
+uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu);
+
+#endif
+