fiatlux/firmware/bus.cpp

#include "bus.h"
#include "esp/gpio.h"

#include <esp/spi.h>
#include <cstdio>
#include "log.h"

uint32_t spi_transfer_32_duplex(uint8_t bus, uint32_t val) {
    uint32_t out = val;
    uint32_t in;
    spi_transfer(bus, &out, &in, 1, SPI_32BIT);
    return in;
}

uint16_t spi_transfer_16_duplex(uint8_t bus, uint32_t val) {
    uint16_t out = val;
    uint16_t in;
    spi_transfer(bus, &out, &in, 1, SPI_16BIT);
    return in;
}

typedef enum {
    CMD_NONE = 0,
    CMD_READ = 1,
    CMD_WRITE = 2,
    CMD_INIT = 3,
    CMD_RESET = 4,
    CMD_VERSION = 5,
    CMD_CONFIG = 6,
    CMD_PING = 7
} bus_cmd;

typedef union {
    struct {
        unsigned dat: 16;
        unsigned addr: 8;
        unsigned cmd: 8;
    } __attribute__((packed));
    uint32_t _;
} request_frame;

typedef union {
    struct {
        unsigned dat: 16;
        unsigned addr: 8;
        unsigned flags: 7;
        unsigned: 1;
    } __attribute__((packed));
    uint32_t _;
} reply_frame;

uint8_t flags = 0;

reply_frame bus_transfer_msg(bus_cmd cmd, uint8_t addr, uint16_t dat) {
    request_frame frame_out = {._=0};
    reply_frame frame_in = {._=0};

    frame_out.cmd = cmd;
    frame_out.addr = addr;
    frame_out.dat = dat;
    spi_transfer_32_duplex(1, frame_out._);
    for (volatile int k = 0; k < 512 * 2; ++k);
    frame_in._ = spi_transfer_32_duplex(1, 0x0000);
    for (volatile int k = 0; k < 512 * 2; ++k);
    flags |= frame_in.flags;
    return frame_in;
}

uint32_t bus_transfer_msg(uint8_t addr, uint16_t dat) {
    return bus_transfer_msg(CMD_WRITE, addr, dat)._;
}

bool bus_transfer_msg_arr(uint8_t addr, uint16_t *dat, uint8_t len) {
    request_frame frame_out = {._=0};
    reply_frame frame_in = {._=0};

    request_frame last_frame = {._=0};
    uint8_t error_count = 0;

    for (int i = 0; i < len; ++i) {

        frame_out.cmd = CMD_WRITE;
        frame_out.addr = addr;
        frame_out.dat = dat[i];

        frame_in._ = spi_transfer_32_duplex(1, frame_out._);

        if(frame_in.dat != last_frame.dat && i != 0) {
            error_count++;

            if(0) {
                syslog(" > ");
                syslog_i32(frame_out._);
                syslog(" < ");
                syslog_i32(frame_in._);
                syslog(" =? ");
                syslog_i32(last_frame._);
                syslog("\n");
            }
            printf(" > %08x < %08x =? %08x\n", frame_out._, frame_in._, last_frame._);
        }

        last_frame._ = frame_out._;

        for (volatile int k = 0; k < 512 * 2; ++k);
    }

    frame_in._ = spi_transfer_32_duplex(1, 0x0000);
    if(frame_in.dat != last_frame.dat) {
        error_count++;

        if(0) {
            syslog(" > ");
            syslog_i32(frame_out._);
            syslog(" < ");
            syslog_i32(frame_in._);
            syslog(" =? ");
            syslog_i32(last_frame._);
            syslog("\n");
        }
        printf(" > %08x < %08x =? %08x\n", 0, frame_in._, last_frame._);
    }

    return error_count == 0;
}

uint16_t bus_get_version() {
    return bus_transfer_msg(15, 0) >> 16;
}

void reset_bus() {
    gpio_write(4, false);
    for (volatile int k = 0; k < 128; ++k);
    gpio_write(4, true);
}

bool bus_init() {
    gpio_enable(12, GPIO_INPUT);
    gpio_set_pullup(12, true, true);
    gpio_write(4, false);
    for (volatile int k = 0; k < 512 * 2; ++k);
    gpio_write(4, true);
    gpio_enable(4, GPIO_OUT_OPEN_DRAIN);
    gpio_write(4, true);
    for (volatile int k = 0; k < 512 * 4; ++k);

    bool miso_state = gpio_read(12);

    if(miso_state) {
        printf("MISO is high, bus is not reset\n");
        return false;
    }
    spi_init(1, SPI_MODE0, SPI_FREQ_DIV_8M, true, SPI_BIG_ENDIAN, false);

    return true;
}

bool bus_init_next() {
    flags &= ~0x04;
    auto reply = bus_transfer_msg(CMD_INIT, 1, 0);
    //printf(" init: %08x \n", reply.flags);
    printf(" init: %02x %02x %04x %08x \n", reply.flags, reply.addr, reply.dat, reply._);
    return reply.flags & 0x04;
}

uint16_t ping_count = 0;

bool bus_ping() {
    auto reply = bus_transfer_msg(CMD_PING, 1, ++ping_count);
    if(reply.dat == ping_count)
        return true;

    printf("ping %02x %04x =? %08x\n", 1, ping_count, reply._);
    return false;
}