[PATCH v2 09/15] HiFive1: add clock driver support

[Denis Obrezkov]

---
 c/src/lib/libbsp/riscv32/hifive1/clock/clock.c   | 60 ++++++++++++++++++++++++
 c/src/lib/libbsp/riscv32/hifive1/include/fe310.h |  5 +-
 c/src/lib/libbsp/riscv32/hifive1/include/irq.h   |  6 ++-
 c/src/lib/libbsp/riscv32/hifive1/irq/irq.c       |  4 +-
 4 files changed, 71 insertions(+), 4 deletions(-)
 create mode 100644 c/src/lib/libbsp/riscv32/hifive1/clock/clock.c

diff --git a/c/src/lib/libbsp/riscv32/hifive1/clock/clock.c b/c/src/lib/libbsp/riscv32/hifive1/clock/clock.c
new file mode 100644
index 0000000..ce20663
--- /dev/null
+++ b/c/src/lib/libbsp/riscv32/hifive1/clock/clock.c
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2017 Denis Obrezkov <denisobrezkov at gmail.com>
+ *
+ * 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/irq.h>
+#include <bsp/fatal.h>
+#include <bsp/fe310.h>
+
+static void FE310_clock_driver_support_install_isr(
+  rtems_isr_entry Clock_isr
+)
+{
+  rtems_status_code sc = RTEMS_SUCCESSFUL;
+    
+  sc = rtems_interrupt_handler_install(
+    1,
+    "Clock",
+    RTEMS_INTERRUPT_UNIQUE,
+    (rtems_interrupt_handler) Clock_isr,
+    NULL
+  );
+  if ( sc != RTEMS_SUCCESSFUL ) {
+    rtems_fatal_error_occurred(0xdeadbeef);
+  }
+}
+
+static void FE310_clock_driver_support_at_tick ( void )
+{
+  (*MTIMECMP) += FE310_CLOCK_PERIOD;
+}
+
+static void FE310_clock_init ( void )
+{
+  (*MTIMECMP) = (*MTIME) + FE310_CLOCK_PERIOD;
+  enable_mtime_interrupts();
+}
+
+static void FE310_clock_driver_support_shutdown_hardware( void )
+{
+}
+
+#define Clock_driver_support_initialize_hardware() \
+  FE310_clock_init()
+
+#define CLOCK_DRIVER_USE_DUMMY_TIMECOUNTER
+
+#define Clock_driver_support_install_isr(isr,old) \
+  FE310_clock_driver_support_install_isr ( isr )
+
+#define Clock_driver_support_at_tick() \
+  FE310_clock_driver_support_at_tick()
+
+#define Clock_driver_support_shutdown_hardware() \
+  FE310_clock_driver_support_shutdown_hardware()
+
+#include "../../../shared/clockdrv_shell.h"
diff --git a/c/src/lib/libbsp/riscv32/hifive1/include/fe310.h b/c/src/lib/libbsp/riscv32/hifive1/include/fe310.h
index c73db99..e32bc38 100644
--- a/c/src/lib/libbsp/riscv32/hifive1/include/fe310.h
+++ b/c/src/lib/libbsp/riscv32/hifive1/include/fe310.h
@@ -23,8 +23,11 @@
 #define USE_PLL
 
 /* Clock parameters */
+/*
+ * FIXME: 512 is a good value just to try out the BSP, 
+ * but additional configuration is required
+ */
 #define FE310_CLOCK_PERIOD 512
-#define CONFIGURE_MICROSECONDS_PER_TICK 15625
 
 
 #endif /* FE310_H */
diff --git a/c/src/lib/libbsp/riscv32/hifive1/include/irq.h b/c/src/lib/libbsp/riscv32/hifive1/include/irq.h
index 46d29c7..8f44089 100644
--- a/c/src/lib/libbsp/riscv32/hifive1/include/irq.h
+++ b/c/src/lib/libbsp/riscv32/hifive1/include/irq.h
@@ -47,7 +47,6 @@
 #define BSP_INTERRUPT_VECTOR_MIN  0x0
 #define BSP_INTERRUPT_VECTOR_MAX  0x24
 
-
 #define MCAUSE_INT 0x80000000
 
 #define MCAUSE_MSWI 0x3
@@ -65,5 +64,10 @@
 #define MTIME     ((volatile uint64_t *)0x0200bff8)
 #define MSIP_REG ((volatile uint32_t *) 0x02000000)
 
+static inline void enable_mtime_interrupts() {
+    asm volatile ("li t0, 0x80\n\t"
+                  "csrs mie, t0");
+}
+
 #endif /* ASM */
 #endif /* LIBBSP_GENERIC_RISCV_IRQ_H */
diff --git a/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c b/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
index fadfdb7..7d7a80b 100644
--- a/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
+++ b/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
@@ -70,8 +70,8 @@ void handle_trap (uint32_t cause)
     if (cause & MCAUSE_INT) { 
       /* an interrupt occurred */
       if ((cause & MCAUSE_MTIME) == MCAUSE_MTIME) {
-	/* Timer interrupt */
-        (*MTIMECMP) = (*MTIME) + FE310_CLOCK_PERIOD;
+    	/* Timer interrupt */
+        /* TODO: Proper (not manual) dispatching should be implemented */
         bsp_interrupt_handler_table[1].handler(bsp_interrupt_handler_table[1].arg);
       } else if ((cause & MCAUSE_MEXT) == MCAUSE_MEXT) {
 	      /*External interrupt */
-- 
2.1.4