/* See LICENSE for license details. */
#include <gd32vf103.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined(__ICCRISCV__)
#include "compiler.h"
#elif defined(__GNUC__)
#include <unistd.h>
#endif

#include "gd32vf103_rcu.h"
#include "n200_func.h"
#include "riscv_encoding.h"

/* Configure PMP to make all the address space accesable and executable */
void pmp_open_all_space(void) {
  /* Config entry0 addr to all 1s to make the range cover all space */
  asm volatile("li x6, 0xffffffff" ::: "x6");
  asm volatile("csrw pmpaddr0, x6" :::);
  /* Config entry0 cfg to make it NAPOT address mode, and R/W/X okay */
  asm volatile("li x6, 0x7f" ::: "x6");
  asm volatile("csrw pmpcfg0, x6" :::);
}

void switch_m2u_mode(void) {
  clear_csr(mstatus, MSTATUS_MPP);
  /* printf("\nIn the m2u function, the mstatus is 0x%x\n", read_csr(mstatus)); */
  /* printf("\nIn the m2u function, the mepc is 0x%x\n", read_csr(mepc)); */
#if defined(__GNUC__)
  asm volatile("la x6, 1f    " ::: "x6");
#endif
  asm volatile("csrw mepc, x6" :::);
  asm volatile("mret" :::);
  asm volatile("1:" :::);
}

uint32_t mtime_lo(void) { return *(volatile uint32_t *)(TIMER_CTRL_ADDR + TIMER_MTIME); }

uint32_t mtime_hi(void) { return *(volatile uint32_t *)(TIMER_CTRL_ADDR + TIMER_MTIME + 4); }

uint64_t get_timer_value(void) {
  while (1) {
    uint32_t hi = mtime_hi();
    uint32_t lo = mtime_lo();
    if (hi == mtime_hi())
      return ((uint64_t)hi << 32) | lo;
  }
}

uint32_t get_timer_freq(void) { return TIMER_FREQ; }

uint64_t get_instret_value(void) {
  while (1) {
#if defined(__ICCRISCV__)
    uint32_t hi = read_csr(CSR_MINSTRETH);
    uint32_t lo = read_csr(CSR_MINSTRETH);
    if (hi == read_csr(CSR_MINSTRETH))
#elif defined(__GNUC__)
    uint32_t hi = read_csr(minstreth);
    uint32_t lo = read_csr(minstret);
    if (hi == read_csr(minstreth))
#endif

      return ((uint64_t)hi << 32) | lo;
  }
}

uint64_t get_cycle_value(void) {
  while (1) {
#if defined(__ICCRISCV__)
    uint32_t hi = read_csr(CSR_MCYCLEH);
    uint32_t lo = read_csr(CSR_MCYCLE);
    if (hi == read_csr(CSR_MCYCLEH))
#elif defined(__GNUC__)
    uint32_t hi = read_csr(mcycleh);
    uint32_t lo = read_csr(mcycle);
    if (hi == read_csr(mcycleh))
#endif

      return ((uint64_t)hi << 32) | lo;
  }
}

/* Note that there are no assertions or bounds checking on these */
/* parameter values. */
void eclic_init(uint32_t num_irq) {

  typedef volatile uint32_t vuint32_t;

  /* clear cfg register */
  *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_CFG_OFFSET) = 0;

  /* clear minthresh register */
  *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_MTH_OFFSET) = 0;

  /* clear all IP/IE/ATTR/CTRL bits for all interrupt sources */
  vuint32_t *ptr;

  vuint32_t *base  = (vuint32_t *)(ECLIC_ADDR_BASE + ECLIC_INT_IP_OFFSET);
  vuint32_t *upper = (vuint32_t *)(base + num_irq * 4);

  for (ptr = base; ptr < upper; ptr = ptr + 4) {
    *ptr = 0;
  }
}

void eclic_enable_interrupt(uint32_t source) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_IE_OFFSET + source * 4) = 1; }

void eclic_disable_interrupt(uint32_t source) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_IE_OFFSET + source * 4) = 0; }

void eclic_set_pending(uint32_t source) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_IP_OFFSET + source * 4) = 1; }

void eclic_clear_pending(uint32_t source) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_IP_OFFSET + source * 4) = 0; }

void eclic_set_intctrl(uint32_t source, uint8_t intctrl) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_CTRL_OFFSET + source * 4) = intctrl; }

uint8_t eclic_get_intctrl(uint32_t source) { return *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_CTRL_OFFSET + source * 4); }

void eclic_set_intattr(uint32_t source, uint8_t intattr) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_ATTR_OFFSET + source * 4) = intattr; }

uint8_t eclic_get_intattr(uint32_t source) { return *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_INT_ATTR_OFFSET + source * 4); }

void eclic_set_cliccfg(uint8_t cliccfg) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_CFG_OFFSET) = cliccfg; }

uint8_t eclic_get_cliccfg(void) { return *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_CFG_OFFSET); }

void eclic_set_mth(uint8_t mth) { *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_MTH_OFFSET) = mth; }

uint8_t eclic_get_mth(void) { return *(volatile uint8_t *)(ECLIC_ADDR_BASE + ECLIC_MTH_OFFSET); }

/* sets nlbits */
void eclic_set_nlbits(uint8_t nlbits) {
  /* shift nlbits to correct position */
  uint8_t nlbits_shifted = nlbits << ECLIC_CFG_NLBITS_LSB;

  /* read the current cliccfg */
  uint8_t old_cliccfg = eclic_get_cliccfg();
  uint8_t new_cliccfg = (old_cliccfg & (~ECLIC_CFG_NLBITS_MASK)) | (ECLIC_CFG_NLBITS_MASK & nlbits_shifted);

  eclic_set_cliccfg(new_cliccfg);
}

/* get nlbits */
uint8_t eclic_get_nlbits(void) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_cliccfg();
  nlbits         = (nlbits & ECLIC_CFG_NLBITS_MASK) >> ECLIC_CFG_NLBITS_LSB;
  return nlbits;
}

/* sets an interrupt level based encoding of nlbits and ECLICINTCTLBITS */
void eclic_set_irq_lvl(uint32_t source, uint8_t lvl) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits > ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
  }

  /* shift lvl right to mask off unused bits */
  lvl = lvl >> (8 - nlbits);
  /* shift lvl into correct bit position */
  lvl = lvl << (8 - nlbits);

  /* write to clicintctrl */
  uint8_t current_intctrl = eclic_get_intctrl(source);
  /* shift intctrl left to mask off unused bits */
  current_intctrl = current_intctrl << nlbits;
  /* shift intctrl into correct bit position */
  current_intctrl = current_intctrl >> nlbits;

  eclic_set_intctrl(source, (current_intctrl | lvl));
}

/* gets an interrupt level based encoding of nlbits */
uint8_t eclic_get_irq_lvl(uint32_t source) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits > ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
  }

  uint8_t intctrl = eclic_get_intctrl(source);

  /* shift intctrl */
  intctrl = intctrl >> (8 - nlbits);
  /* shift intctrl */
  uint8_t lvl = intctrl << (8 - nlbits);

  return lvl;
}

void eclic_set_irq_lvl_abs(uint32_t source, uint8_t lvl_abs) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits > ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
  }

  /* shift lvl_abs into correct bit position */
  uint8_t lvl = lvl_abs << (8 - nlbits);

  /* write to clicintctrl */
  uint8_t current_intctrl = eclic_get_intctrl(source);
  /* shift intctrl left to mask off unused bits */
  current_intctrl = current_intctrl << nlbits;
  /* shift intctrl into correct bit position */
  current_intctrl = current_intctrl >> nlbits;

  eclic_set_intctrl(source, (current_intctrl | lvl));
}

uint8_t eclic_get_irq_lvl_abs(uint32_t source) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits > ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
  }

  uint8_t intctrl = eclic_get_intctrl(source);

  /* shift intctrl */
  intctrl = intctrl >> (8 - nlbits);
  /* shift intctrl */
  uint8_t lvl_abs = intctrl;

  return lvl_abs;
}

/* sets an interrupt priority based encoding of nlbits and ECLICINTCTLBITS */
uint8_t eclic_set_irq_priority(uint32_t source, uint8_t priority) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits >= ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
    return 0;
  }

  /* shift priority into correct bit position */
  priority = priority << (8 - ECLICINTCTLBITS);

  /* write to eclicintctrl */
  uint8_t current_intctrl = eclic_get_intctrl(source);
  /* shift intctrl right to mask off unused bits */
  current_intctrl = current_intctrl >> (8 - nlbits);
  /* shift intctrl into correct bit position */
  current_intctrl = current_intctrl << (8 - nlbits);

  eclic_set_intctrl(source, (current_intctrl | priority));

  return priority;
}

/* gets an interrupt priority based encoding of nlbits */
uint8_t eclic_get_irq_priority(uint32_t source) {
  /* extract nlbits */
  uint8_t nlbits = eclic_get_nlbits();
  if (nlbits > ECLICINTCTLBITS) {
    nlbits = ECLICINTCTLBITS;
  }

  uint8_t intctrl = eclic_get_intctrl(source);

  /* shift intctrl */
  intctrl = intctrl << nlbits;
  /* shift intctrl */
  uint8_t priority = intctrl >> (nlbits + (8 - ECLICINTCTLBITS));

  return priority;
}

void eclic_mode_enable() {
#if defined(__ICCRISCV__)
  uint32_t mtvec_value = read_csr(CSR_MTVEC);
  mtvec_value          = mtvec_value & 0xFFFFFFC0;
  mtvec_value          = mtvec_value | 0x00000003;
  write_csr(CSR_MTVEC, mtvec_value);
#elif defined(__GNUC__)
  uint32_t mtvec_value = read_csr(mtvec);
  mtvec_value = mtvec_value & 0xFFFFFFC0;
  mtvec_value = mtvec_value | 0x00000003;
  write_csr(mtvec, mtvec_value);
#endif
}

/* sets vector-mode or non-vector mode */
void eclic_set_vmode(uint32_t source) {
  /* read the current attr */
  uint8_t old_intattr = eclic_get_intattr(source);
  /*  Keep other bits unchanged and only set the LSB bit */
  uint8_t new_intattr = (old_intattr | 0x1);

  eclic_set_intattr(source, new_intattr);
}

void eclic_set_nonvmode(uint32_t source) {
  /* read the current attr */
  uint8_t old_intattr = eclic_get_intattr(source);
  /* Keep other bits unchanged and only clear the LSB bit*/
  uint8_t new_intattr = (old_intattr & (~0x1));

  eclic_set_intattr(source, new_intattr);
}

/* sets interrupt as level sensitive
Bit 1, trig[0], is defined as "edge-triggered" (0: level-triggered, 1: edge-triggered);
Bit 2, trig[1], is defined as "negative-edge" (0: positive-edge, 1: negative-edge).*/

void eclic_set_level_trig(uint32_t source) {
  /* read the current attr */
  uint8_t old_intattr = eclic_get_intattr(source);
  /* Keep other bits unchanged and only clear the bit 1 */
  uint8_t new_intattr = (old_intattr & (~0x2));

  eclic_set_intattr(source, new_intattr);
}

void eclic_set_posedge_trig(uint32_t source) {
  /* read the current attr */
  uint8_t old_intattr = eclic_get_intattr(source);
  /* Keep other bits unchanged and only set the bit 1 */
  uint8_t new_intattr = (old_intattr | 0x2);
  /* Keep other bits unchanged and only clear the bit 2 */
  new_intattr = (old_intattr & (~0x4));

  eclic_set_intattr(source, new_intattr);
}

void eclic_set_negedge_trig(uint32_t source) {
  /*read the current attr */
  uint8_t old_intattr = eclic_get_intattr(source);
  /* Keep other bits unchanged and only set the bit 1*/
  uint8_t new_intattr = (old_intattr | 0x2);
  /* Keep other bits unchanged and only set the bit 2*/
  new_intattr = (old_intattr | 0x4);

  eclic_set_intattr(source, new_intattr);
}
