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Diffstat (limited to 'code/fe310/drivers/plic_driver.c')
-rw-r--r--code/fe310/drivers/plic_driver.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/code/fe310/drivers/plic_driver.c b/code/fe310/drivers/plic_driver.c
new file mode 100644
index 0000000..27b9d2c
--- /dev/null
+++ b/code/fe310/drivers/plic_driver.c
@@ -0,0 +1,127 @@
+// See LICENSE for license details.
+
+#include "sifive/devices/plic.h"
+#include "plic_driver.h"
+#include "platform.h"
+#include "encoding.h"
+#include <string.h>
+
+
+// Note that there are no assertions or bounds checking on these
+// parameter values.
+
+void volatile_memzero(uint8_t * base, unsigned int size)
+{
+ volatile uint8_t * ptr;
+ for (ptr = base; ptr < (base + size); ptr++){
+ *ptr = 0;
+ }
+}
+
+void PLIC_init (
+ plic_instance_t * this_plic,
+ uintptr_t base_addr,
+ uint32_t num_sources,
+ uint32_t num_priorities
+ )
+{
+
+ this_plic->base_addr = base_addr;
+ this_plic->num_sources = num_sources;
+ this_plic->num_priorities = num_priorities;
+
+ // Disable all interrupts (don't assume that these registers are reset).
+ unsigned long hart_id = read_csr(mhartid);
+ volatile_memzero((uint8_t*) (this_plic->base_addr +
+ PLIC_ENABLE_OFFSET +
+ (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET)),
+ (num_sources + 8) / 8);
+
+ // Set all priorities to 0 (equal priority -- don't assume that these are reset).
+ volatile_memzero ((uint8_t *)(this_plic->base_addr +
+ PLIC_PRIORITY_OFFSET),
+ (num_sources + 1) << PLIC_PRIORITY_SHIFT_PER_SOURCE);
+
+ // Set the threshold to 0.
+ volatile plic_threshold* threshold = (plic_threshold*)
+ (this_plic->base_addr +
+ PLIC_THRESHOLD_OFFSET +
+ (hart_id << PLIC_THRESHOLD_SHIFT_PER_TARGET));
+
+ *threshold = 0;
+
+}
+
+void PLIC_set_threshold (plic_instance_t * this_plic,
+ plic_threshold threshold){
+
+ unsigned long hart_id = read_csr(mhartid);
+ volatile plic_threshold* threshold_ptr = (plic_threshold*) (this_plic->base_addr +
+ PLIC_THRESHOLD_OFFSET +
+ (hart_id << PLIC_THRESHOLD_SHIFT_PER_TARGET));
+
+ *threshold_ptr = threshold;
+
+}
+
+
+void PLIC_enable_interrupt (plic_instance_t * this_plic, plic_source source){
+
+ unsigned long hart_id = read_csr(mhartid);
+ volatile uint8_t * current_ptr = (volatile uint8_t *)(this_plic->base_addr +
+ PLIC_ENABLE_OFFSET +
+ (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET) +
+ (source >> 3));
+ uint8_t current = *current_ptr;
+ current = current | ( 1 << (source & 0x7));
+ *current_ptr = current;
+
+}
+
+void PLIC_disable_interrupt (plic_instance_t * this_plic, plic_source source){
+
+ unsigned long hart_id = read_csr(mhartid);
+ volatile uint8_t * current_ptr = (volatile uint8_t *) (this_plic->base_addr +
+ PLIC_ENABLE_OFFSET +
+ (hart_id << PLIC_ENABLE_SHIFT_PER_TARGET) +
+ (source >> 3));
+ uint8_t current = *current_ptr;
+ current = current & ~(( 1 << (source & 0x7)));
+ *current_ptr = current;
+
+}
+
+void PLIC_set_priority (plic_instance_t * this_plic, plic_source source, plic_priority priority){
+
+ if (this_plic->num_priorities > 0) {
+ volatile plic_priority * priority_ptr = (volatile plic_priority *)
+ (this_plic->base_addr +
+ PLIC_PRIORITY_OFFSET +
+ (source << PLIC_PRIORITY_SHIFT_PER_SOURCE));
+ *priority_ptr = priority;
+ }
+}
+
+plic_source PLIC_claim_interrupt(plic_instance_t * this_plic){
+
+ unsigned long hart_id = read_csr(mhartid);
+
+ volatile plic_source * claim_addr = (volatile plic_source * )
+ (this_plic->base_addr +
+ PLIC_CLAIM_OFFSET +
+ (hart_id << PLIC_CLAIM_SHIFT_PER_TARGET));
+
+ return *claim_addr;
+
+}
+
+void PLIC_complete_interrupt(plic_instance_t * this_plic, plic_source source){
+
+ unsigned long hart_id = read_csr(mhartid);
+ volatile plic_source * claim_addr = (volatile plic_source *) (this_plic->base_addr +
+ PLIC_CLAIM_OFFSET +
+ (hart_id << PLIC_CLAIM_SHIFT_PER_TARGET));
+ *claim_addr = source;
+
+}
+