#include <stdio.h>
#include <stdlib.h>

#include "encoding.h"
#include "platform.h"

#include "eos.h"
#include "soc/timer.h"

#include "flash.h"

#define IDLE_TICKS  10

__attribute__ ((section (".itim.flash")))
static void send(uint8_t data) {
    while (SPI0_REG(SPI_REG_TXFIFO) & SPI_TXFIFO_FULL);
    SPI0_REG(SPI_REG_TXFIFO) = data;
}

__attribute__ ((section (".itim.flash")))
static uint8_t xfer(uint8_t data) {
    volatile uint32_t x = 0;

    send(data);
    while ((x = SPI0_REG(SPI_REG_RXFIFO)) & SPI_RXFIFO_EMPTY);
    return x;
}

void eos_flash_init(void) {
    SPI0_REG(SPI_REG_FMT) |= SPI_FMT_DIR(SPI_DIR_TX);
    SPI0_REG(SPI_REG_TXCTRL) = SPI_TXWM(1);
    eos_flash_norm();
}

__attribute__ ((section (".itim.flash")))
void eos_flash_norm(void) {
    volatile uint64_t *mtime = (uint64_t *) (CLINT_CTRL_ADDR + CLINT_MTIME);
    uint32_t mtime0;

    clear_csr(mstatus, MSTATUS_MIE);
    SPI0_REG(SPI_REG_FCTRL) = 0;

    SPI0_REG(SPI_REG_SCKDIV) = 3;
    if (SPI0_REG(SPI_REG_FMT) & SPI_FMT_PROTO(SPI_PROTO_Q)) {
        send(EOS_FLASH_QPIDI);
        while (!(SPI0_REG(SPI_REG_IP) & SPI_IP_TXWM));
    }

    SPI0_REG(SPI_REG_FMT) = \
        SPI_FMT_PROTO(SPI_PROTO_S)      |
        SPI_FMT_ENDIAN(SPI_ENDIAN_MSB)  |
        SPI_FMT_DIR(SPI_DIR_TX)         |
        SPI_FMT_LEN(8);

    SPI0_REG(SPI_REG_FFMT) =
        SPI_INSN_CMD_EN         |
        SPI_INSN_ADDR_LEN(3)    |
	    SPI_INSN_PAD_CNT(0)     |
	    SPI_INSN_CMD_PROTO(SPI_PROTO_S)     |
	    SPI_INSN_ADDR_PROTO(SPI_PROTO_S)    |
	    SPI_INSN_DATA_PROTO(SPI_PROTO_S)    |
	    SPI_INSN_CMD_CODE(EOS_FLASH_NORD)   |
	    SPI_INSN_PAD_CODE(0x00);

    mtime0 = *mtime;
    while ((*mtime - mtime0) < IDLE_TICKS);

    SPI0_REG(SPI_REG_FCTRL) = SPI_FCTRL_EN;
    set_csr(mstatus, MSTATUS_MIE);
}

__attribute__ ((section (".itim.flash")))
void eos_flash_fast(void) {
    volatile uint64_t *mtime = (uint64_t *) (CLINT_CTRL_ADDR + CLINT_MTIME);
    uint32_t mtime0;

    clear_csr(mstatus, MSTATUS_MIE);
    SPI0_REG(SPI_REG_FCTRL) = 0;

    SPI0_REG(SPI_REG_SCKDIV) = 2;
    if (!(SPI0_REG(SPI_REG_FMT) & SPI_FMT_PROTO(SPI_PROTO_Q))) {
        send(EOS_FLASH_QPIEN);
        while (!(SPI0_REG(SPI_REG_IP) & SPI_IP_TXWM));
    }

    SPI0_REG(SPI_REG_FMT) = \
        SPI_FMT_PROTO(SPI_PROTO_Q)      |
        SPI_FMT_ENDIAN(SPI_ENDIAN_MSB)  |
        SPI_FMT_DIR(SPI_DIR_TX)         |
        SPI_FMT_LEN(8);

    SPI0_REG(SPI_REG_FFMT) =
        SPI_INSN_CMD_EN         |
        SPI_INSN_ADDR_LEN(3)    |
	    SPI_INSN_PAD_CNT(6)     |
	    SPI_INSN_CMD_PROTO(SPI_PROTO_Q)     |
	    SPI_INSN_ADDR_PROTO(SPI_PROTO_Q)    |
	    SPI_INSN_DATA_PROTO(SPI_PROTO_Q)    |
	    SPI_INSN_CMD_CODE(EOS_FLASH_FRD)    |
	    SPI_INSN_PAD_CODE(0x00);

    mtime0 = *mtime;
    while ((*mtime - mtime0) < IDLE_TICKS);

    SPI0_REG(SPI_REG_FCTRL) = SPI_FCTRL_EN;
    set_csr(mstatus, MSTATUS_MIE);
}

__attribute__ ((section (".itim.flash")))
void eos_flash_wip(void) {
    uint8_t status;

    do {
        SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_HOLD;
        xfer(EOS_FLASH_RDSR);
        status = xfer(0);
        SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_AUTO;
    } while (status & EOS_FLASH_WIP);
}

__attribute__ ((section (".itim.flash")))
void eos_flash_wren(void) {
    uint8_t status;

    xfer(EOS_FLASH_WREN);
#if 0
    do {
        SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_HOLD;
        xfer(EOS_FLASH_RDSR);
        status = xfer(0);
        SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_AUTO;
    } while (!(status & EOS_FLASH_WEL));
#endif
}

__attribute__ ((section (".itim.flash")))
void eos_flash_ser(uint32_t addr) {
    SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_HOLD;
    xfer(EOS_FLASH_SER);
    xfer(addr >> 16);
    xfer(addr >> 8);
    xfer(addr);
    SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_AUTO;
}

__attribute__ ((section (".itim.flash")))
void eos_flash_pp(uint32_t addr, uint8_t *buf) {
    int i;

    SPI0_REG(SPI_REG_FMT) |= SPI_FMT_DIR(SPI_DIR_TX);
    SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_HOLD;
    send(EOS_FLASH_PP);
    send(addr >> 16);
    send(addr >> 8);
    send(addr);
    for (i=0; i<256; i++) {
        send(buf[i]);
    }
    while (!(SPI0_REG(SPI_REG_IP) & SPI_IP_TXWM));
    SPI0_REG(SPI_REG_CSMODE) = SPI_CSMODE_AUTO;
    SPI0_REG(SPI_REG_FMT) &= ~SPI_FMT_DIR(SPI_DIR_TX);
}