#include <stdlib.h>
#include <stdint.h>

#include "eos.h"

#include "soc/spi.h"

#include "arducam.h"

#define ARDUCAM_REG_CAPTURE_CTRL        0x01
#define ARDUCAM_REG_FIFO_CTRL           0x04

#define ARDUCAM_REG_GPIO_DIR            0x05
#define ARDUCAM_REG_GPIO_WR             0x06
#define ARDUCAM_REG_GPIO_RD             0x45

#define ARDUCAM_REG_STATUS              0x41

#define ARDUCAM_REG_VER                 0x40

#define ARDUCAM_REG_READ_BURST          0x3c
#define ARDUCAM_REG_READ_BYTE           0x3d

#define ARDUCAM_REG_FIFO_SIZE1          0x42
#define ARDUCAM_REG_FIFO_SIZE2          0x43
#define ARDUCAM_REG_FIFO_SIZE3          0x44

#define ARDUCAM_VAL_FIFO_CTRL_CLEAR     0x01
#define ARDUCAM_VAL_FIFO_CTRL_START     0x02
#define ARDUCAM_VAL_FIFO_CTRL_RSTWR     0x10
#define ARDUCAM_VAL_FIFO_CTRL_RSTRD     0x20

#define ARDUCAM_VAL_STATUS_VSYNC        0x01
#define ARDUCAM_VAL_STATUS_SHUTTER      0x02
#define ARDUCAM_VAL_STATUS_CPTDONE      0x08

#define ARDUCAM_VAL_GPIO_RST            0x01
#define ARDUCAM_VAL_GPIO_PWRDN          0x02
#define ARDUCAM_VAL_GPIO_PWREN          0x04

static uint8_t reg_read(uint8_t addr) {
    uint8_t ret;

    eos_spi_cs_set();
    eos_spi_xchg8(addr, 0);
    ret = eos_spi_xchg8(0, 0);
    eos_spi_cs_clear();

    return ret;
}

static void reg_write(uint8_t addr, uint8_t val) {
    eos_spi_cs_set();
    eos_spi_xchg8(addr | 0x80, 0);
    eos_spi_xchg8(val, 0);
    eos_spi_cs_clear();
}

void arducam_capture(void) {
    reg_write(ARDUCAM_REG_FIFO_CTRL, ARDUCAM_VAL_FIFO_CTRL_START);
}

int arducam_capture_done(void) {
    return !!(reg_read(ARDUCAM_REG_STATUS) & ARDUCAM_VAL_STATUS_CPTDONE);
}

void arducam_capture_wait(void) {
    int done = 0;

    while (!done) {
        done = arducam_capture_done();
    }
}

uint32_t arducam_fbuf_size(void) {
    uint32_t ret;

	ret = reg_read(ARDUCAM_REG_FIFO_SIZE1);
    ret |= reg_read(ARDUCAM_REG_FIFO_SIZE2) << 8;
    ret |= (reg_read(ARDUCAM_REG_FIFO_SIZE3) & 0x7f) << 16;
    return ret;
}

void arducam_fbuf_read(uint8_t *buffer, uint16_t sz, int first) {
    int i;

    eos_spi_cs_set();
    eos_spi_xchg8(ARDUCAM_REG_READ_BURST, 0);
    if (first) eos_spi_xchg8(0, 0);

    for (i=0; i<sz; i++) {
        buffer[i] = eos_spi_xchg8(0, 0);
    }
    eos_spi_cs_clear();
}

void arducam_fbuf_done(void) {
    reg_write(ARDUCAM_REG_FIFO_CTRL, ARDUCAM_VAL_FIFO_CTRL_CLEAR);
}