From e877048417454b0baca5d4a5aceed72a6602c3be Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 5 May 2010 23:45:01 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ftdi_sio.c | 53 +++++++++-------------------------- 1 file changed, 13 insertions(+), 40 deletions(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index a41974e1768..f515f32cde6 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -71,10 +71,6 @@ struct ftdi_private { /* the last data state set - needed for doing * a break */ - int write_offset; /* This is the offset in the usb data block to - * write the serial data - it varies between - * devices - */ int flags; /* some ASYNC_xxxx flags are supported */ unsigned long last_dtr_rts; /* saved modem control outputs */ wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */ @@ -1279,7 +1275,6 @@ static void ftdi_determine_type(struct usb_serial_port *port) /* Assume it is not the original SIO device for now. */ priv->baud_base = 48000000 / 2; - priv->write_offset = 0; version = le16_to_cpu(udev->descriptor.bcdDevice); interfaces = udev->actconfig->desc.bNumInterfaces; @@ -1321,7 +1316,6 @@ static void ftdi_determine_type(struct usb_serial_port *port) /* Old device. Assume it's the original SIO. */ priv->chip_type = SIO; priv->baud_base = 12000000 / 16; - priv->write_offset = 1; } else if (version < 0x400) { /* Assume it's an FT8U232AM (or FT8U245AM) */ /* (It might be a BM because of the iSerialNumber bug, @@ -1757,50 +1751,29 @@ static int ftdi_prepare_write_buffer(struct usb_serial_port *port, { struct ftdi_private *priv; unsigned char *buffer; - int data_offset ; /* will be 1 for the SIO and 0 otherwise */ - int transfer_size; + int len; priv = usb_get_serial_port_data(port); - data_offset = priv->write_offset; - dbg("data_offset set to %d", data_offset); + len = count; + if (priv->chip_type == SIO && count != 0) + len += ((count - 1) / (priv->max_packet_size - 1)) + 1; - /* Determine total transfer size */ - transfer_size = count; - if (data_offset > 0) { - /* Original sio needs control bytes too... */ - transfer_size += (data_offset * - ((count + (priv->max_packet_size - 1 - data_offset)) / - (priv->max_packet_size - data_offset))); - } - - buffer = kmalloc(transfer_size, GFP_ATOMIC); + buffer = kmalloc(len, GFP_ATOMIC); if (!buffer) { dev_err(&port->dev, "%s - could not allocate buffer\n", __func__); return -ENOMEM; } - /* Copy data */ - if (data_offset > 0) { - /* Original sio requires control byte at start of - each packet. */ - int user_pktsz = priv->max_packet_size - data_offset; - int todo = count; - unsigned char *first_byte = buffer; - const unsigned char *current_position = src; - - while (todo > 0) { - if (user_pktsz > todo) - user_pktsz = todo; - /* Write the control byte at the front of the packet*/ - *first_byte = 1 | ((user_pktsz) << 2); - /* Copy data for packet */ - memcpy(first_byte + data_offset, - current_position, user_pktsz); - first_byte += user_pktsz + data_offset; - current_position += user_pktsz; - todo -= user_pktsz; + if (priv->chip_type == SIO) { + int i, msg_len; + + for (i = 0; i < len; i += priv->max_packet_size) { + msg_len = min_t(int, len - i, priv->max_packet_size) - 1; + buffer[i] = (msg_len << 2) + 1; + memcpy(&buffer[i + 1], src, msg_len); + src += msg_len; } } else { memcpy(buffer, src, count); -- 2.46.0