// SPDX-License-Identifier: GPL-2.0 /* * Opticon USB barcode to serial driver * * Copyright (C) 2011 - 2012 Johan Hovold * Copyright (C) 2011 Martin Jansen * Copyright (C) 2008 - 2009 Greg Kroah-Hartman * Copyright (C) 2008 - 2009 Novell Inc. */ #include #include #include #include #include #include #include #include #include #include #define CONTROL_RTS 0x02 #define RESEND_CTS_STATE 0x03 /* max number of write urbs in flight */ #define URB_UPPER_LIMIT 8 /* This driver works for the Opticon 1D barcode reader * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */ #define DRIVER_DESC "Opticon USB barcode to serial driver (1D)" static const struct usb_device_id id_table[] = { { USB_DEVICE(0x065a, 0x0009) }, { }, }; MODULE_DEVICE_TABLE(usb, id_table); /* This structure holds all of the individual device information */ struct opticon_private { spinlock_t lock; /* protects the following flags */ bool rts; bool cts; int outstanding_urbs; int outstanding_bytes; struct usb_anchor anchor; }; static void opticon_process_data_packet(struct usb_serial_port *port, const unsigned char *buf, size_t len) { tty_insert_flip_string(&port->port, buf, len); tty_flip_buffer_push(&port->port); } static void opticon_process_status_packet(struct usb_serial_port *port, const unsigned char *buf, size_t len) { struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; spin_lock_irqsave(&priv->lock, flags); if (buf[0] == 0x00) priv->cts = false; else priv->cts = true; spin_unlock_irqrestore(&priv->lock, flags); } static void opticon_process_read_urb(struct urb *urb) { struct usb_serial_port *port = urb->context; const unsigned char *hdr = urb->transfer_buffer; const unsigned char *data = hdr + 2; size_t data_len = urb->actual_length - 2; if (urb->actual_length <= 2) { dev_dbg(&port->dev, "malformed packet received: %d bytes\n", urb->actual_length); return; } /* * Data from the device comes with a 2 byte header: * * <0x00><0x00>data... * This is real data to be sent to the tty layer * <0x00><0x01>level * This is a CTS level change, the third byte is the CTS * value (0 for low, 1 for high). */ if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) { opticon_process_data_packet(port, data, data_len); } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) { opticon_process_status_packet(port, data, data_len); } else { dev_dbg(&port->dev, "unknown packet received: %02x %02x\n", hdr[0], hdr[1]); } } static int send_control_msg(struct usb_serial_port *port, u8 requesttype, u8 val) { struct usb_serial *serial = port->serial; int retval; u8 *buffer; buffer = kzalloc(1, GFP_KERNEL); if (!buffer) return -ENOMEM; buffer[0] = val; /* Send the message to the vendor control endpoint * of the connected device */ retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), requesttype, USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE, 0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT); kfree(buffer); if (retval < 0) return retval; return 0; } static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port) { struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; int res; spin_lock_irqsave(&priv->lock, flags); priv->rts = false; spin_unlock_irqrestore(&priv->lock, flags); /* Clear RTS line */ send_control_msg(port, CONTROL_RTS, 0); /* clear the halt status of the endpoint */ usb_clear_halt(port->serial->dev, port->read_urb->pipe); res = usb_serial_generic_open(tty, port); if (res) return res; /* Request CTS line state, sometimes during opening the current * CTS state can be missed. */ send_control_msg(port, RESEND_CTS_STATE, 1); return res; } static void opticon_close(struct usb_serial_port *port) { struct opticon_private *priv = usb_get_serial_port_data(port); usb_kill_anchored_urbs(&priv->anchor); usb_serial_generic_close(port); } static void opticon_write_control_callback(struct urb *urb) { struct usb_serial_port *port = urb->context; struct opticon_private *priv = usb_get_serial_port_data(port); int status = urb->status; unsigned long flags; /* free up the transfer buffer, as usb_free_urb() does not do this */ kfree(urb->transfer_buffer); /* setup packet may be set if we're using it for writing */ kfree(urb->setup_packet); if (status) dev_dbg(&port->dev, "%s - non-zero urb status received: %d\n", __func__, status); spin_lock_irqsave(&priv->lock, flags); --priv->outstanding_urbs; priv->outstanding_bytes -= urb->transfer_buffer_length; spin_unlock_irqrestore(&priv->lock, flags); usb_serial_port_softint(port); } static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct opticon_private *priv = usb_get_serial_port_data(port); struct usb_serial *serial = port->serial; struct urb *urb; unsigned char *buffer; unsigned long flags; struct usb_ctrlrequest *dr; int ret = -ENOMEM; spin_lock_irqsave(&priv->lock, flags); if (priv->outstanding_urbs > URB_UPPER_LIMIT) { spin_unlock_irqrestore(&priv->lock, flags); dev_dbg(&port->dev, "%s - write limit hit\n", __func__); return 0; } priv->outstanding_urbs++; priv->outstanding_bytes += count; spin_unlock_irqrestore(&priv->lock, flags); buffer = kmemdup(buf, count, GFP_ATOMIC); if (!buffer) goto error_no_buffer; urb = usb_alloc_urb(0, GFP_ATOMIC); if (!urb) goto error_no_urb; usb_serial_debug_data(&port->dev, __func__, count, buffer); /* The connected devices do not have a bulk write endpoint, * to transmit data to de barcode device the control endpoint is used */ dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); if (!dr) goto error_no_dr; dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; dr->bRequest = 0x01; dr->wValue = 0; dr->wIndex = 0; dr->wLength = cpu_to_le16(count); usb_fill_control_urb(urb, serial->dev, usb_sndctrlpipe(serial->dev, 0), (unsigned char *)dr, buffer, count, opticon_write_control_callback, port); usb_anchor_urb(urb, &priv->anchor); /* send it down the pipe */ ret = usb_submit_urb(urb, GFP_ATOMIC); if (ret) { dev_err(&port->dev, "failed to submit write urb: %d\n", ret); usb_unanchor_urb(urb); goto error; } /* we are done with this urb, so let the host driver * really free it when it is finished with it */ usb_free_urb(urb); return count; error: kfree(dr); error_no_dr: usb_free_urb(urb); error_no_urb: kfree(buffer); error_no_buffer: spin_lock_irqsave(&priv->lock, flags); --priv->outstanding_urbs; priv->outstanding_bytes -= count; spin_unlock_irqrestore(&priv->lock, flags); return ret; } static unsigned int opticon_write_room(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; /* * We really can take almost anything the user throws at us * but let's pick a nice big number to tell the tty * layer that we have lots of free space, unless we don't. */ spin_lock_irqsave(&priv->lock, flags); if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { spin_unlock_irqrestore(&priv->lock, flags); dev_dbg(&port->dev, "%s - write limit hit\n", __func__); return 0; } spin_unlock_irqrestore(&priv->lock, flags); return 2048; } static unsigned int opticon_chars_in_buffer(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; unsigned int count; spin_lock_irqsave(&priv->lock, flags); count = priv->outstanding_bytes; spin_unlock_irqrestore(&priv->lock, flags); return count; } static int opticon_tiocmget(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; int result = 0; spin_lock_irqsave(&priv->lock, flags); if (priv->rts) result |= TIOCM_RTS; if (priv->cts) result |= TIOCM_CTS; spin_unlock_irqrestore(&priv->lock, flags); dev_dbg(&port->dev, "%s - %x\n", __func__, result); return result; } static int opticon_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct usb_serial_port *port = tty->driver_data; struct opticon_private *priv = usb_get_serial_port_data(port); unsigned long flags; bool rts; bool changed = false; int ret; /* We only support RTS so we only handle that */ spin_lock_irqsave(&priv->lock, flags); rts = priv->rts; if (set & TIOCM_RTS) priv->rts = true; if (clear & TIOCM_RTS) priv->rts = false; changed = rts ^ priv->rts; spin_unlock_irqrestore(&priv->lock, flags); if (!changed) return 0; ret = send_control_msg(port, CONTROL_RTS, !rts); if (ret) return usb_translate_errors(ret); return 0; } static int opticon_port_probe(struct usb_serial_port *port) { struct opticon_private *priv; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; spin_lock_init(&priv->lock); init_usb_anchor(&priv->anchor); usb_set_serial_port_data(port, priv); return 0; } static void opticon_port_remove(struct usb_serial_port *port) { struct opticon_private *priv = usb_get_serial_port_data(port); kfree(priv); } static struct usb_serial_driver opticon_device = { .driver = { .name = "opticon", }, .id_table = id_table, .num_ports = 1, .num_bulk_in = 1, .bulk_in_size = 256, .port_probe = opticon_port_probe, .port_remove = opticon_port_remove, .open = opticon_open, .close = opticon_close, .write = opticon_write, .write_room = opticon_write_room, .chars_in_buffer = opticon_chars_in_buffer, .throttle = usb_serial_generic_throttle, .unthrottle = usb_serial_generic_unthrottle, .tiocmget = opticon_tiocmget, .tiocmset = opticon_tiocmset, .process_read_urb = opticon_process_read_urb, }; static struct usb_serial_driver * const serial_drivers[] = { &opticon_device, NULL }; module_usb_serial_driver(serial_drivers, id_table); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL v2");