// SPDX-License-Identifier: GPL-2.0
/*
* Opticon USB barcode to serial driver
*
* Copyright (C) 2011 - 2012 Johan Hovold <[email protected]>
* Copyright (C) 2011 Martin Jansen <[email protected]>
* Copyright (C) 2008 - 2009 Greg Kroah-Hartman <[email protected]>
* Copyright (C) 2008 - 2009 Novell Inc.
*/
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/slab.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
#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");
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