/**
* Write data of a certain length to the LA8's FTDI device.
*
* @param devc The struct containing private per-device-instance data. Must not
* be NULL. devc->ftdic must not be NULL either.
* @param buf The buffer containing the data to write. Must not be NULL.
* @param size The number of bytes to write. Must be >= 0.
* @return The number of bytes written, or a negative value upon errors.
*/
SR_PRIV int la8_write(struct dev_context *devc, uint8_t *buf, int size)
{
int bytes_written;
/* Note: Caller checked that devc and devc->ftdic != NULL. */
if (!buf) {
sr_err("%s: buf was NULL.", __func__);
return SR_ERR_ARG;
}
if (size < 0) {
sr_err("%s: size was < 0.", __func__);
return SR_ERR_ARG;
}
bytes_written = ftdi_write_data(devc->ftdic, buf, size);
if (bytes_written < 0) {
sr_err("%s: ftdi_write_data: (%d) %s.", __func__,
bytes_written, ftdi_get_error_string(devc->ftdic));
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
} else if (bytes_written != size) {
sr_err("%s: bytes to write: %d, bytes written: %d.",
__func__, size, bytes_written);
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
}
return bytes_written;
}
static int dev_open(struct sr_dev_inst *sdi)
{
struct dev_context *devc;
int ret;
if (!(devc = sdi->priv)) {
sr_err("%s: sdi->priv was NULL.", __func__);
return SR_ERR_BUG;
}
sr_dbg("Opening LA8 device (%04x:%04x).", USB_VENDOR_ID,
devc->usb_pid);
/* Open the device. */
if ((ret = ftdi_usb_open_desc(devc->ftdic, USB_VENDOR_ID,
devc->usb_pid, USB_DESCRIPTION, NULL)) < 0) {
sr_err("%s: ftdi_usb_open_desc: (%d) %s",
__func__, ret, ftdi_get_error_string(devc->ftdic));
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
return SR_ERR;
}
sr_dbg("Device opened successfully.");
/* Purge RX/TX buffers in the FTDI chip. */
if ((ret = ftdi_usb_purge_buffers(devc->ftdic)) < 0) {
sr_err("%s: ftdi_usb_purge_buffers: (%d) %s",
__func__, ret, ftdi_get_error_string(devc->ftdic));
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
goto err_dev_open_close_ftdic;
}
sr_dbg("FTDI buffers purged successfully.");
/* Enable flow control in the FTDI chip. */
if ((ret = ftdi_setflowctrl(devc->ftdic, SIO_RTS_CTS_HS)) < 0) {
sr_err("%s: ftdi_setflowcontrol: (%d) %s",
__func__, ret, ftdi_get_error_string(devc->ftdic));
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
goto err_dev_open_close_ftdic;
}
sr_dbg("FTDI flow control enabled successfully.");
/* Wait 100ms. */
g_usleep(100 * 1000);
sdi->status = SR_ST_ACTIVE;
return SR_OK;
err_dev_open_close_ftdic:
(void) la8_close(devc); /* Log, but ignore errors. */
return SR_ERR;
}
static int dev_close(struct sr_dev_inst *sdi)
{
struct dev_context *devc;
devc = sdi->priv;
if (sdi->status == SR_ST_ACTIVE) {
sr_dbg("Status ACTIVE, closing device.");
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
} else {
sr_spew("Status not ACTIVE, nothing to do.");
}
sdi->status = SR_ST_INACTIVE;
return SR_OK;
}
/**
* Reset the ChronoVu LA8.
*
* The LA8 must be reset after a failed read/write operation or upon timeouts.
*
* @param devc The struct containing private per-device-instance data.
* @return SR_OK upon success, SR_ERR upon failure.
*/
SR_PRIV int la8_reset(struct dev_context *devc)
{
uint8_t buf[BS];
time_t done, now;
int bytes_read;
if (!devc) {
sr_err("%s: devc was NULL.", __func__);
return SR_ERR_ARG;
}
if (!devc->ftdic) {
sr_err("%s: devc->ftdic was NULL.", __func__);
return SR_ERR_ARG;
}
sr_dbg("Resetting the device.");
/*
* Purge pending read data from the FTDI hardware FIFO until
* no more data is left, or a timeout occurs (after 20s).
*/
done = 20 + time(NULL);
do {
/* TODO: Ignore errors? Check for < 0 at least! */
bytes_read = la8_read(devc, (uint8_t *)&buf, BS);
now = time(NULL);
} while ((done > now) && (bytes_read > 0));
/* Reset the LA8 sequencer logic and close the USB port. */
(void) la8_close_usb_reset_sequencer(devc); /* Ignore errors. */
sr_dbg("Device reset finished.");
return SR_OK;
}
