ftdi.c

libftdi - A library (using libusb) to talk to FTDI s FT2232C, FT232BM and FT245BM type chips includ

    ftdi->bitbang_enabled = 1;
    return 0;
}

/**
    Disable bitbang mode.

    \param ftdi pointer to ftdi_context

    \retval  0: all fine
    \retval -1: can't disable bitbang mode
*/
int ftdi_disable_bitbang(struct ftdi_context *ftdi)
{
    if (usb_control_msg(ftdi->usb_dev, 0x40, 0x0B, 0, ftdi->index, NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "unable to leave bitbang mode. Perhaps not a BM type chip?");

    ftdi->bitbang_enabled = 0;
    return 0;
}

/**
    Enable advanced bitbang mode for FT2232C chips.

    \param ftdi pointer to ftdi_context
    \param bitmask Bitmask to configure lines.
           HIGH/ON value configures a line as output.
    \param mode Bitbang mode: 1 for normal mode, 2 for SPI mode

    \retval  0: all fine
    \retval -1: can't enable bitbang mode
*/
int ftdi_set_bitmode(struct ftdi_context *ftdi, unsigned char bitmask, unsigned char mode)
{
    unsigned short usb_val;

    usb_val = bitmask; // low byte: bitmask
    usb_val |= (mode << 8);
    if (usb_control_msg(ftdi->usb_dev, 0x40, 0x0B, usb_val, ftdi->index, NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "unable to configure bitbang mode. Perhaps not a 2232C type chip?");

    ftdi->bitbang_mode = mode;
    ftdi->bitbang_enabled = (mode == BITMODE_BITBANG || mode == BITMODE_SYNCBB)?1:0;
    return 0;
}

/**
    Directly read pin state. Useful for bitbang mode.

    \param ftdi pointer to ftdi_context
    \param pins Pointer to store pins into

    \retval  0: all fine
    \retval -1: read pins failed
*/
int ftdi_read_pins(struct ftdi_context *ftdi, unsigned char *pins)
{
    if (usb_control_msg(ftdi->usb_dev, 0xC0, 0x0C, 0, ftdi->index, (char *)pins, 1, ftdi->usb_read_timeout) != 1)
        ftdi_error_return(-1, "read pins failed");

    return 0;
}

/**
    Set latency timer

    The FTDI chip keeps data in the internal buffer for a specific
    amount of time if the buffer is not full yet to decrease
    load on the usb bus.

    \param ftdi pointer to ftdi_context
    \param latency Value between 1 and 255

    \retval  0: all fine
    \retval -1: latency out of range
    \retval -2: unable to set latency timer
*/
int ftdi_set_latency_timer(struct ftdi_context *ftdi, unsigned char latency)
{
    unsigned short usb_val;

    if (latency < 1)
        ftdi_error_return(-1, "latency out of range. Only valid for 1-255");

    usb_val = latency;
    if (usb_control_msg(ftdi->usb_dev, 0x40, 0x09, usb_val, ftdi->index, NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-2, "unable to set latency timer");

    return 0;
}

/**
    Get latency timer

    \param ftdi pointer to ftdi_context
    \param latency Pointer to store latency value in

    \retval  0: all fine
    \retval -1: unable to get latency timer
*/
int ftdi_get_latency_timer(struct ftdi_context *ftdi, unsigned char *latency)
{
    unsigned short usb_val;
    if (usb_control_msg(ftdi->usb_dev, 0xC0, 0x0A, 0, ftdi->index, (char *)&usb_val, 1, ftdi->usb_read_timeout) != 1)
        ftdi_error_return(-1, "reading latency timer failed");

    *latency = (unsigned char)usb_val;
    return 0;
}

/**
    Init eeprom with default values.

    \param eeprom Pointer to ftdi_eeprom
*/
void ftdi_eeprom_initdefaults(struct ftdi_eeprom *eeprom)
{
    eeprom->vendor_id = 0x0403;
    eeprom->product_id = 0x6001;

    eeprom->self_powered = 1;
    eeprom->remote_wakeup = 1;
    eeprom->BM_type_chip = 1;

    eeprom->in_is_isochronous = 0;
    eeprom->out_is_isochronous = 0;
    eeprom->suspend_pull_downs = 0;

    eeprom->use_serial = 0;
    eeprom->change_usb_version = 0;
    eeprom->usb_version = 0x0200;
    eeprom->max_power = 0;

    eeprom->manufacturer = NULL;
    eeprom->product = NULL;
    eeprom->serial = NULL;
}

/**
   Build binary output from ftdi_eeprom structure.
   Output is suitable for ftdi_write_eeprom().

   \param eeprom Pointer to ftdi_eeprom
   \param output Buffer of 128 bytes to store eeprom image to

   \retval >0: used eeprom size
   \retval -1: eeprom size (128 bytes) exceeded by custom strings
*/
int ftdi_eeprom_build(struct ftdi_eeprom *eeprom, unsigned char *output)
{
    unsigned char i, j;
    unsigned short checksum, value;
    unsigned char manufacturer_size = 0, product_size = 0, serial_size = 0;
    int size_check;

    if (eeprom->manufacturer != NULL)
        manufacturer_size = strlen(eeprom->manufacturer);
    if (eeprom->product != NULL)
        product_size = strlen(eeprom->product);
    if (eeprom->serial != NULL)
        serial_size = strlen(eeprom->serial);

    size_check = 128; // eeprom is 128 bytes
    size_check -= 28; // 28 are always in use (fixed)
    size_check -= manufacturer_size*2;
    size_check -= product_size*2;
    size_check -= serial_size*2;

    // eeprom size exceeded?
    if (size_check < 0)
        return (-1);

    // empty eeprom
    memset (output, 0, 128);

    // Addr 00: Stay 00 00
    // Addr 02: Vendor ID
    output[0x02] = eeprom->vendor_id;
    output[0x03] = eeprom->vendor_id >> 8;

    // Addr 04: Product ID
    output[0x04] = eeprom->product_id;
    output[0x05] = eeprom->product_id >> 8;

    // Addr 06: Device release number (0400h for BM features)
    output[0x06] = 0x00;

    if (eeprom->BM_type_chip == 1)
        output[0x07] = 0x04;
    else
        output[0x07] = 0x02;

    // Addr 08: Config descriptor
    // Bit 1: remote wakeup if 1
    // Bit 0: self powered if 1
    //
    j = 0;
    if (eeprom->self_powered == 1)
        j = j | 1;
    if (eeprom->remote_wakeup == 1)
        j = j | 2;
    output[0x08] = j;

    // Addr 09: Max power consumption: max power = value * 2 mA
    output[0x09] = eeprom->max_power;
    ;

    // Addr 0A: Chip configuration
    // Bit 7: 0 - reserved
    // Bit 6: 0 - reserved
    // Bit 5: 0 - reserved
    // Bit 4: 1 - Change USB version
    // Bit 3: 1 - Use the serial number string
    // Bit 2: 1 - Enable suspend pull downs for lower power
    // Bit 1: 1 - Out EndPoint is Isochronous
    // Bit 0: 1 - In EndPoint is Isochronous
    //
    j = 0;
    if (eeprom->in_is_isochronous == 1)
        j = j | 1;
    if (eeprom->out_is_isochronous == 1)
        j = j | 2;
    if (eeprom->suspend_pull_downs == 1)
        j = j | 4;
    if (eeprom->use_serial == 1)
        j = j | 8;
    if (eeprom->change_usb_version == 1)
        j = j | 16;
    output[0x0A] = j;

    // Addr 0B: reserved
    output[0x0B] = 0x00;

    // Addr 0C: USB version low byte when 0x0A bit 4 is set
    // Addr 0D: USB version high byte when 0x0A bit 4 is set
    if (eeprom->change_usb_version == 1) {
        output[0x0C] = eeprom->usb_version;
        output[0x0D] = eeprom->usb_version >> 8;
    }


    // Addr 0E: Offset of the manufacturer string + 0x80
    output[0x0E] = 0x14 + 0x80;

    // Addr 0F: Length of manufacturer string
    output[0x0F] = manufacturer_size*2 + 2;

    // Addr 10: Offset of the product string + 0x80, calculated later
    // Addr 11: Length of product string
    output[0x11] = product_size*2 + 2;

    // Addr 12: Offset of the serial string + 0x80, calculated later
    // Addr 13: Length of serial string
    output[0x13] = serial_size*2 + 2;

    // Dynamic content
    output[0x14] = manufacturer_size*2 + 2;
    output[0x15] = 0x03; // type: string

    i = 0x16, j = 0;

    // Output manufacturer
    for (j = 0; j < manufacturer_size; j++) {
        output[i] = eeprom->manufacturer[j], i++;
        output[i] = 0x00, i++;
    }

    // Output product name
    output[0x10] = i + 0x80;  // calculate offset
    output[i] = product_size*2 + 2, i++;
    output[i] = 0x03, i++;
    for (j = 0; j < product_size; j++) {
        output[i] = eeprom->product[j], i++;
        output[i] = 0x00, i++;
    }

    // Output serial
    output[0x12] = i + 0x80; // calculate offset
    output[i] = serial_size*2 + 2, i++;
    output[i] = 0x03, i++;
    for (j = 0; j < serial_size; j++) {
        output[i] = eeprom->serial[j], i++;
        output[i] = 0x00, i++;
    }

    // calculate checksum
    checksum = 0xAAAA;

    for (i = 0; i < 63; i++) {
        value = output[i*2];
        value += output[(i*2)+1] << 8;

        checksum = value^checksum;
        checksum = (checksum << 1) | (checksum >> 15);
    }

    output[0x7E] = checksum;
    output[0x7F] = checksum >> 8;

    return size_check;
}

/**
    Read eeprom

    \param ftdi pointer to ftdi_context
    \param eeprom Pointer to store eeprom into

    \retval  0: all fine
    \retval -1: read failed
*/
int ftdi_read_eeprom(struct ftdi_context *ftdi, unsigned char *eeprom)
{
    int i;

    for (i = 0; i < 64; i++) {
        if (usb_control_msg(ftdi->usb_dev, 0xC0, 0x90, 0, i, eeprom+(i*2), 2, ftdi->usb_read_timeout) != 2)
            ftdi_error_return(-1, "reading eeprom failed");
    }

    return 0;
}

/**
    Write eeprom

    \param ftdi pointer to ftdi_context
    \param eeprom Pointer to read eeprom from

    \retval  0: all fine
    \retval -1: read failed
*/
int ftdi_write_eeprom(struct ftdi_context *ftdi, unsigned char *eeprom)
{
    unsigned short usb_val;
    int i;

    for (i = 0; i < 64; i++) {
        usb_val = eeprom[i*2];
        usb_val += eeprom[(i*2)+1] << 8;
        if (usb_control_msg(ftdi->usb_dev, 0x40, 0x91, usb_val, i, NULL, 0, ftdi->usb_write_timeout) != 0)
            ftdi_error_return(-1, "unable to write eeprom");
    }

    return 0;
}

/**
    Erase eeprom

    \param ftdi pointer to ftdi_context

    \retval  0: all fine
    \retval -1: erase failed
*/
int ftdi_erase_eeprom(struct ftdi_context *ftdi)
{
    if (usb_control_msg(ftdi->usb_dev, 0x40, 0x92, 0, 0, NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "unable to erase eeprom");

    return 0;
}

/**
    Get string representation for last error code

    \param ftdi pointer to ftdi_context

    \retval Pointer to error string
*/
char *ftdi_get_error_string (struct ftdi_context *ftdi)
{
    return ftdi->error_str;
}

/*
    Flow control code by Lorenz Moesenlechner ([e-mail])
    and Matthias Kranz  ([e-mail])
*/
/**
    Set flowcontrol for ftdi chip

    \param ftdi pointer to ftdi_context
    \param flowctrl flow control to use. should be 
           SIO_DISABLE_FLOW_CTRL, SIO_RTS_CTS_HS, SIO_DTR_DSR_HS or SIO_XON_XOFF_HS   

    \retval  0: all fine
    \retval -1: set flow control failed
*/
int ftdi_setflowctrl(struct ftdi_context *ftdi, int flowctrl)
{
    if (usb_control_msg(ftdi->usb_dev, SIO_SET_FLOW_CTRL_REQUEST_TYPE,
                        SIO_SET_FLOW_CTRL_REQUEST, 0, (flowctrl | ftdi->interface),
                        NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "set flow control failed");

    return 0;
}

/**
    Set dtr line

    \param ftdi pointer to ftdi_context
    \param state state to set line to (1 or 0)

    \retval  0: all fine
    \retval -1: set dtr failed
*/
int ftdi_setdtr(struct ftdi_context *ftdi, int state)
{
    unsigned short usb_val;

    if (state)
        usb_val = SIO_SET_DTR_HIGH;
    else
        usb_val = SIO_SET_DTR_LOW;

    if (usb_control_msg(ftdi->usb_dev, SIO_SET_MODEM_CTRL_REQUEST_TYPE,
                        SIO_SET_MODEM_CTRL_REQUEST, usb_val, ftdi->interface,
                        NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "set dtr failed");

    return 0;
}

/**
    Set rts line

    \param ftdi pointer to ftdi_context
    \param state state to set line to (1 or 0)

    \retval  0: all fine
    \retval -1 set rts failed
*/
int ftdi_setrts(struct ftdi_context *ftdi, int state)
{
    unsigned short usb_val;

    if (state)
        usb_val = SIO_SET_RTS_HIGH;
    else
        usb_val = SIO_SET_RTS_LOW;

    if (usb_control_msg(ftdi->usb_dev, SIO_SET_MODEM_CTRL_REQUEST_TYPE,
                        SIO_SET_MODEM_CTRL_REQUEST, usb_val, ftdi->interface,
                        NULL, 0, ftdi->usb_write_timeout) != 0)
        ftdi_error_return(-1, "set of rts failed");

    return 0;
}

/* @} end of doxygen libftdi group */