Add a CLIC interrupt example

This example is fairly simple, but it does at least demonstrate how to
use a C-based preemptable interrupt handler that's been registered in
CLIC mode on a SiFive E21.

1 files changed, 49 insertions, 0 deletions

diff --git a/bsp/include/sifive/devices/clic.h b/bsp/include/sifive/devices/clic.h
new file mode 100644
index 0000000..b31e1ce
--- /dev/null
+++ b/bsp/include/sifive/devices/clic.h
@@ -0,0 +1,49 @@
+// See LICENSE for license details.
+
+#ifndef _SIFIVE_CLIC_H
+#define _SIFIVE_CLIC_H
+
+#define CLIC_CTRL_ADDR _AC(0x2000000,UL)
+
+#define CLIC_MSIP           0x0000
+#define CLIC_MSIP_size      0x4
+#define CLIC_MTIMECMP       0x4000
+#define CLIC_MTIMECMP_size  0x8
+#define CLIC_MTIME          0xBFF8
+#define CLIC_MTIME_size     0x8
+
+#define CLIC_INTIP          0x0800000
+#define CLIC_INTIE          0x0800400
+#define CLIC_INTCFG         0x0800800
+#define CLIC_CFG            0x0800c00
+
+// These interrupt IDs are consistent across old and new mtvec modes
+#define SSIPID              1
+#define MSIPID              3
+#define STIPID              5
+#define MTIPID              7
+#define SEIPID              9
+#define MEIPID              11
+#define CSIPID              12
+#define LOCALINTIDBASE      16
+
+#define CLIC_REG(offset)    _REG32(CLIC_CTRL_ADDR, offset)
+#define CLIC_REG8(offset)   (*(volatile uint8_t *)((CLIC_CTRL_ADDR) + (offset)))
+
+#ifndef CLINT_CTRL_ADDR
+#define CLINT_CTRL_ADDR CLIC_CTRL_ADDR
+#endif
+#ifndef CLINT_REG
+#define CLINT_REG CLIC_REG
+#endif
+#ifndef CLINT_MSIP
+#define CLINT_MSIP CLIC_MSIP
+#endif
+#ifndef CLINT_MTIME
+#define CLINT_MTIME CLIC_MTIME
+#endif
+#ifndef CLINT_MTIMECMP
+#define CLINT_MTIMECMP CLIC_MTIMECMP
+#endif
+
+#endif /* _SIFIVE_CLIC_H */