1 files changed, 115 insertions, 0 deletions
diff --git a/bsps/riscv/griscv/start/amba.c b/bsps/riscv/griscv/start/amba.c
new file mode 100644
index 0000000000..182f659d69
--- /dev/null
+++ b/bsps/riscv/griscv/start/amba.c
@@ -0,0 +1,115 @@
+
+/*
+ *  Find and initialize irqmp and gptimer.
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+
+#include <bsp.h>
+#include <bsp/fatal.h>
+#include <amba.h>
+
+rtems_interrupt_lock GRLIB_IrqCtrl_Lock =
+  RTEMS_INTERRUPT_LOCK_INITIALIZER("GRLIB IrqCtrl");
+
+/* Pointers to Interrupt Controller configuration registers */
+volatile struct irqmp_regs *GRLIB_IrqCtrl_Regs;
+struct ambapp_dev *GRLIB_IrqCtrl_Adev;
+
+/* GRLIB extended IRQ controller IRQ number */
+int GRLIB_IrqCtrl_EIrq = -1;
+
+/* Initialize Extended Interrupt controller */
+static void grlib_ext_irq_init(void)
+{
+  if ( (GRLIB_IrqCtrl_Regs->mpstat >> 16) & 0xf ) {
+    /* Extended IRQ controller available */
+    GRLIB_IrqCtrl_EIrq = (GRLIB_IrqCtrl_Regs->mpstat >> 16) & 0xf;
+  }
+}
+
+/*
+ *  irqmp_initialize
+ *
+ *  Probes for IRQMP and initialises necessary registers.
+ *
+ */
+
+void irqmp_initialize(void)
+{
+  int icsel;
+  struct ambapp_dev *adev;
+
+  /* Find GRLIB Interrupt controller */
+  adev = (void *)ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS),
+                                 VENDOR_GAISLER, GAISLER_IRQMP,
+                                 ambapp_find_by_idx, NULL);
+  if (adev != NULL) {
+
+    GRLIB_IrqCtrl_Regs = (volatile struct irqmp_regs *)DEV_TO_APB(adev)->start;
+    GRLIB_IrqCtrl_Adev = adev;
+    if ((GRLIB_IrqCtrl_Regs->ampctrl >> 28) > 0) {
+    /* IRQ Controller has support for multiple IRQ Controllers, each
+     * CPU can be routed to different Controllers, we find out which
+     * controller by looking at the IRQCTRL Select Register for this CPU.
+     * Each Controller is located at a 4KByte offset.
+     */
+      icsel = GRLIB_IrqCtrl_Regs->icsel[GRLIB_Cpu_Index/8];
+      icsel = (icsel >> ((7 - (GRLIB_Cpu_Index & 0x7)) * 4)) & 0xf;
+      GRLIB_IrqCtrl_Regs += icsel;
+    }
+    GRLIB_IrqCtrl_Regs->mask[GRLIB_Cpu_Index] = 0;
+    GRLIB_IrqCtrl_Regs->force[GRLIB_Cpu_Index] = 0;
+    GRLIB_IrqCtrl_Regs->iclear = 0xffffffff;
+
+  /* Init Extended IRQ controller if available */
+    grlib_ext_irq_init();
+
+  }
+
+}
+
+
+/* GPTIMER */
+
+unsigned int grlib_timer_prescaler __attribute__((weak)) = 0;
+int grlib_timer_core_index __attribute__((weak)) = 0;
+
+volatile struct gptimer_regs *GRLIB_Timer_Regs;
+struct ambapp_dev *GRLIB_Timer_Adev;
+
+/*
+ *  gptimer_initialize
+ *
+ */
+
+void gptimer_initialize(void)
+{
+  struct ambapp_dev *adev;
+
+  /* find GP Timer */
+  adev = (void *)ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS),
+                                 VENDOR_GAISLER, GAISLER_GPTIMER,
+                                 ambapp_find_by_idx, &grlib_timer_core_index);
+  if (adev) {
+    GRLIB_Timer_Regs = (volatile struct gptimer_regs *)DEV_TO_APB(adev)->start;
+    GRLIB_Timer_Adev = adev;
+
+    /* Register AMBA Bus Frequency */
+    ambapp_freq_init(
+      &ambapp_plb,
+      GRLIB_Timer_Adev,
+      (GRLIB_Timer_Regs->scaler_reload + 1)
+        * GRLIB_GPTIMER_0_FREQUENCY_SET_BY_BOOT_LOADER
+    );
+    /* Set user prescaler configuration. Use this to increase accuracy of timer
+     * and accociated services like cpucounter.
+     * Note that minimum value is the number of timer instances present in
+     * GRTIMER/GPTIMER hardware. See HW manual.
+     */
+    if (grlib_timer_prescaler)
+      GRLIB_Timer_Regs->scaler_reload = grlib_timer_prescaler;
+  }
+
+}