diff options
Diffstat (limited to 'drivers/usb/serial/symbolserial.c')
| -rw-r--r-- | drivers/usb/serial/symbolserial.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c new file mode 100644 index 000000000..6ca24e86f --- /dev/null +++ b/drivers/usb/serial/symbolserial.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Symbol USB barcode to serial driver + * + * Copyright (C) 2013 Johan Hovold <jhovold@gmail.com> + * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de> + * Copyright (C) 2009 Novell Inc. + */ + +#include <linux/kernel.h> +#include <linux/tty.h> +#include <linux/slab.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> +#include <linux/module.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> +#include <linux/uaccess.h> + +static const struct usb_device_id id_table[] = { + { USB_DEVICE(0x05e0, 0x0600) }, + { }, +}; +MODULE_DEVICE_TABLE(usb, id_table); + +struct symbol_private { + spinlock_t lock; /* protects the following flags */ + bool throttled; + bool actually_throttled; +}; + +static void symbol_int_callback(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + struct symbol_private *priv = usb_get_serial_port_data(port); + unsigned char *data = urb->transfer_buffer; + int status = urb->status; + unsigned long flags; + int result; + int data_length; + + switch (status) { + case 0: + /* success */ + break; + case -ECONNRESET: + case -ENOENT: + case -ESHUTDOWN: + /* this urb is terminated, clean up */ + dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n", + __func__, status); + return; + default: + dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n", + __func__, status); + goto exit; + } + + usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data); + + /* + * Data from the device comes with a 1 byte header: + * + * <size of data> <data>... + */ + if (urb->actual_length > 1) { + data_length = data[0]; + if (data_length > (urb->actual_length - 1)) + data_length = urb->actual_length - 1; + tty_insert_flip_string(&port->port, &data[1], data_length); + tty_flip_buffer_push(&port->port); + } else { + dev_dbg(&port->dev, "%s - short packet\n", __func__); + } + +exit: + spin_lock_irqsave(&priv->lock, flags); + + /* Continue trying to always read if we should */ + if (!priv->throttled) { + result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC); + if (result) + dev_err(&port->dev, + "%s - failed resubmitting read urb, error %d\n", + __func__, result); + } else + priv->actually_throttled = true; + spin_unlock_irqrestore(&priv->lock, flags); +} + +static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port) +{ + struct symbol_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + int result = 0; + + spin_lock_irqsave(&priv->lock, flags); + priv->throttled = false; + priv->actually_throttled = false; + spin_unlock_irqrestore(&priv->lock, flags); + + /* Start reading from the device */ + result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); + if (result) + dev_err(&port->dev, + "%s - failed resubmitting read urb, error %d\n", + __func__, result); + return result; +} + +static void symbol_close(struct usb_serial_port *port) +{ + usb_kill_urb(port->interrupt_in_urb); +} + +static void symbol_throttle(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct symbol_private *priv = usb_get_serial_port_data(port); + + spin_lock_irq(&priv->lock); + priv->throttled = true; + spin_unlock_irq(&priv->lock); +} + +static void symbol_unthrottle(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct symbol_private *priv = usb_get_serial_port_data(port); + int result; + bool was_throttled; + + spin_lock_irq(&priv->lock); + priv->throttled = false; + was_throttled = priv->actually_throttled; + priv->actually_throttled = false; + spin_unlock_irq(&priv->lock); + + if (was_throttled) { + result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); + if (result) + dev_err(&port->dev, + "%s - failed submitting read urb, error %d\n", + __func__, result); + } +} + +static int symbol_port_probe(struct usb_serial_port *port) +{ + struct symbol_private *priv; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + + usb_set_serial_port_data(port, priv); + + return 0; +} + +static int symbol_port_remove(struct usb_serial_port *port) +{ + struct symbol_private *priv = usb_get_serial_port_data(port); + + kfree(priv); + + return 0; +} + +static struct usb_serial_driver symbol_device = { + .driver = { + .owner = THIS_MODULE, + .name = "symbol", + }, + .id_table = id_table, + .num_ports = 1, + .num_interrupt_in = 1, + .port_probe = symbol_port_probe, + .port_remove = symbol_port_remove, + .open = symbol_open, + .close = symbol_close, + .throttle = symbol_throttle, + .unthrottle = symbol_unthrottle, + .read_int_callback = symbol_int_callback, +}; + +static struct usb_serial_driver * const serial_drivers[] = { + &symbol_device, NULL +}; + +module_usb_serial_driver(serial_drivers, id_table); + +MODULE_LICENSE("GPL v2"); |