USB: ftdi_sio: clean up SIO write support
The original SIO devices require a control byte for every packet written. Clean up the unnecessarily messy implementation of this. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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@ -71,10 +71,6 @@ struct ftdi_private {
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/* the last data state set - needed for doing
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* a break
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*/
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int write_offset; /* This is the offset in the usb data block to
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* write the serial data - it varies between
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* devices
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*/
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int flags; /* some ASYNC_xxxx flags are supported */
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unsigned long last_dtr_rts; /* saved modem control outputs */
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wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
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@ -1279,7 +1275,6 @@ static void ftdi_determine_type(struct usb_serial_port *port)
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/* Assume it is not the original SIO device for now. */
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priv->baud_base = 48000000 / 2;
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priv->write_offset = 0;
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version = le16_to_cpu(udev->descriptor.bcdDevice);
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interfaces = udev->actconfig->desc.bNumInterfaces;
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@ -1321,7 +1316,6 @@ static void ftdi_determine_type(struct usb_serial_port *port)
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/* Old device. Assume it's the original SIO. */
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priv->chip_type = SIO;
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priv->baud_base = 12000000 / 16;
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priv->write_offset = 1;
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} else if (version < 0x400) {
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/* Assume it's an FT8U232AM (or FT8U245AM) */
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/* (It might be a BM because of the iSerialNumber bug,
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@ -1757,50 +1751,29 @@ static int ftdi_prepare_write_buffer(struct usb_serial_port *port,
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{
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struct ftdi_private *priv;
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unsigned char *buffer;
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int data_offset ; /* will be 1 for the SIO and 0 otherwise */
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int transfer_size;
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int len;
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priv = usb_get_serial_port_data(port);
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data_offset = priv->write_offset;
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dbg("data_offset set to %d", data_offset);
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len = count;
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if (priv->chip_type == SIO && count != 0)
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len += ((count - 1) / (priv->max_packet_size - 1)) + 1;
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/* Determine total transfer size */
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transfer_size = count;
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if (data_offset > 0) {
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/* Original sio needs control bytes too... */
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transfer_size += (data_offset *
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((count + (priv->max_packet_size - 1 - data_offset)) /
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(priv->max_packet_size - data_offset)));
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}
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buffer = kmalloc(transfer_size, GFP_ATOMIC);
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buffer = kmalloc(len, GFP_ATOMIC);
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if (!buffer) {
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dev_err(&port->dev, "%s - could not allocate buffer\n",
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__func__);
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return -ENOMEM;
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}
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/* Copy data */
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if (data_offset > 0) {
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/* Original sio requires control byte at start of
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each packet. */
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int user_pktsz = priv->max_packet_size - data_offset;
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int todo = count;
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unsigned char *first_byte = buffer;
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const unsigned char *current_position = src;
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if (priv->chip_type == SIO) {
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int i, msg_len;
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while (todo > 0) {
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if (user_pktsz > todo)
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user_pktsz = todo;
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/* Write the control byte at the front of the packet*/
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*first_byte = 1 | ((user_pktsz) << 2);
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/* Copy data for packet */
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memcpy(first_byte + data_offset,
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current_position, user_pktsz);
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first_byte += user_pktsz + data_offset;
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current_position += user_pktsz;
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todo -= user_pktsz;
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for (i = 0; i < len; i += priv->max_packet_size) {
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msg_len = min_t(int, len - i, priv->max_packet_size) - 1;
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buffer[i] = (msg_len << 2) + 1;
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memcpy(&buffer[i + 1], src, msg_len);
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src += msg_len;
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}
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} else {
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memcpy(buffer, src, count);
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