USB: serial: add symbol serial driver

This is for the Symbol 6608 barcode scanner in a fake "HID" mode.

Thanks to Dalibor Grgec for working with me to get this to start to work
properly.

Cc: Dalibor Grgec <dalibor.grgec@zemris.fer.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 350 insertions, 0 deletions

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index b361f05cafac..dbc0781a4163 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -515,6 +515,15 @@ config USB_SERIAL_SIERRAWIRELESS
           To compile this driver as a module, choose M here: the
           module will be called sierra.
 
+config USB_SERIAL_SYMBOL
+        tristate "USB Symbol Barcode driver (serial mode)"
+        help
+          Say Y here if you want to use a Symbol USB Barcode device
+          in serial emulation mode.
+
+          To compile this driver as a module, choose M here: the
+          module will be called symbolserial.
+
 config USB_SERIAL_TI
         tristate "USB TI 3410/5052 Serial Driver"
         help
diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index b75be91eb8f1..222939739ffe 100644
--- a/drivers/usb/serial/Makefile
+++ b/drivers/usb/serial/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_USB_SERIAL_SAFE)			+= safe_serial.o
 obj-$(CONFIG_USB_SERIAL_SIEMENS_MPI)            += siemens_mpi.o
 obj-$(CONFIG_USB_SERIAL_SIERRAWIRELESS)         += sierra.o
 obj-$(CONFIG_USB_SERIAL_SPCP8X5)                += spcp8x5.o
+obj-$(CONFIG_USB_SERIAL_SYMBOL)                 += symbolserial.o
 obj-$(CONFIG_USB_SERIAL_TI)                     += ti_usb_3410_5052.o
 obj-$(CONFIG_USB_SERIAL_VISOR)                  += visor.o
 obj-$(CONFIG_USB_SERIAL_WHITEHEAT)              += whiteheat.o
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c
new file mode 100644
index 000000000000..c5990fd88e2c
--- /dev/null
+++ b/drivers/usb/serial/symbolserial.c
@@ -0,0 +1,340 @@
+/*
+ * Symbol USB barcode to serial driver
+ *
+ * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (C) 2009 Novell Inc.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License version
+ *      2 as published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/tty.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 int debug;
+
+static struct usb_device_id id_table[] = {
+        { USB_DEVICE(0x05e0, 0x0600) },
+        { },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* This structure holds all of the individual device information */
+struct symbol_private {
+        struct usb_device *udev;
+        struct usb_serial *serial;
+        struct usb_serial_port *port;
+        unsigned char *int_buffer;
+        struct urb *int_urb;
+        int buffer_size;
+        u8 bInterval;
+        u8 int_address;
+        spinlock_t lock;        /* protects the following flags */
+        bool throttled;
+        bool actually_throttled;
+        bool rts;
+};
+
+static void symbol_int_callback(struct urb *urb)
+{
+        struct symbol_private *priv = urb->context;
+        unsigned char *data = urb->transfer_buffer;
+        struct usb_serial_port *port = priv->port;
+        int status = urb->status;
+        struct tty_struct *tty;
+        int result;
+        int available_room = 0;
+        int data_length;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        switch (status) {
+        case 0:
+                /* success */
+                break;
+        case -ECONNRESET:
+        case -ENOENT:
+        case -ESHUTDOWN:
+                /* this urb is terminated, clean up */
+                dbg("%s - urb shutting down with status: %d",
+                    __func__, status);
+                return;
+        default:
+                dbg("%s - nonzero urb status received: %d",
+                    __func__, status);
+                goto exit;
+        }
+
+        usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
+                              data);
+
+        if (urb->actual_length > 1) {
+                data_length = urb->actual_length - 1;
+
+                /*
+                 * Data from the device comes with a 1 byte header:
+                 *
+                 * <size of data>data...
+                 *      This is real data to be sent to the tty layer
+                 * we pretty much just ignore the size and send everything
+                 * else to the tty layer.
+                 */
+                tty = tty_port_tty_get(&port->port);
+                if (tty) {
+                        available_room = tty_buffer_request_room(tty,
+                                                        data_length);
+                        if (available_room) {
+                                tty_insert_flip_string(tty, &data[1],
+                                                       available_room);
+                                tty_flip_buffer_push(tty);
+                        }
+                        tty_kref_put(tty);
+                }
+        } else {
+                dev_dbg(&priv->udev->dev,
+                        "Improper ammount of data received from the device, "
+                        "%d bytes", urb->actual_length);
+        }
+
+exit:
+        spin_lock(&priv->lock);
+
+        /* Continue trying to always read if we should */
+        if (!priv->throttled) {
+                usb_fill_int_urb(priv->int_urb, priv->udev,
+                                 usb_rcvintpipe(priv->udev,
+                                                priv->int_address),
+                                 priv->int_buffer, priv->buffer_size,
+                                 symbol_int_callback, priv, priv->bInterval);
+                result = usb_submit_urb(priv->int_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(&priv->lock);
+}
+
+static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port,
+                        struct file *filp)
+{
+        struct symbol_private *priv = usb_get_serial_data(port->serial);
+        unsigned long flags;
+        int result = 0;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        spin_lock_irqsave(&priv->lock, flags);
+        priv->throttled = false;
+        priv->actually_throttled = false;
+        priv->port = port;
+        spin_unlock_irqrestore(&priv->lock, flags);
+
+        /*
+         * Force low_latency on so that our tty_push actually forces the data
+         * through, otherwise it is scheduled, and with high data rates (like
+         * with OHCI) data can get lost.
+         */
+        if (tty)
+                tty->low_latency = 1;
+
+        /* Start reading from the device */
+        usb_fill_int_urb(priv->int_urb, priv->udev,
+                         usb_rcvintpipe(priv->udev, priv->int_address),
+                         priv->int_buffer, priv->buffer_size,
+                         symbol_int_callback, priv, priv->bInterval);
+        result = usb_submit_urb(priv->int_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 tty_struct *tty, struct usb_serial_port *port,
+                          struct file *filp)
+{
+        struct symbol_private *priv = usb_get_serial_data(port->serial);
+
+        dbg("%s - port %d", __func__, port->number);
+
+        /* shutdown our urbs */
+        usb_kill_urb(priv->int_urb);
+}
+
+static void symbol_throttle(struct tty_struct *tty)
+{
+        struct usb_serial_port *port = tty->driver_data;
+        struct symbol_private *priv = usb_get_serial_data(port->serial);
+        unsigned long flags;
+
+        dbg("%s - port %d", __func__, port->number);
+        spin_lock_irqsave(&priv->lock, flags);
+        priv->throttled = true;
+        spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static void symbol_unthrottle(struct tty_struct *tty)
+{
+        struct usb_serial_port *port = tty->driver_data;
+        struct symbol_private *priv = usb_get_serial_data(port->serial);
+        unsigned long flags;
+        int result;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        spin_lock_irqsave(&priv->lock, flags);
+        priv->throttled = false;
+        priv->actually_throttled = false;
+        spin_unlock_irqrestore(&priv->lock, flags);
+
+        priv->int_urb->dev = port->serial->dev;
+        result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
+        if (result)
+                dev_err(&port->dev,
+                        "%s - failed submitting read urb, error %d\n",
+                                                        __func__, result);
+}
+
+static int symbol_startup(struct usb_serial *serial)
+{
+        struct symbol_private *priv;
+        struct usb_host_interface *intf;
+        int i;
+        int retval = -ENOMEM;
+        bool int_in_found = false;
+
+        /* create our private serial structure */
+        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+        if (priv == NULL) {
+                dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
+                return -ENOMEM;
+        }
+        spin_lock_init(&priv->lock);
+        priv->serial = serial;
+        priv->port = serial->port[0];
+        priv->udev = serial->dev;
+
+        /* find our interrupt endpoint */
+        intf = serial->interface->altsetting;
+        for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
+                struct usb_endpoint_descriptor *endpoint;
+
+                endpoint = &intf->endpoint[i].desc;
+                if (!usb_endpoint_is_int_in(endpoint))
+                        continue;
+
+                priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
+                if (!priv->int_urb) {
+                        dev_err(&priv->udev->dev, "out of memory\n");
+                        goto error;
+                }
+
+                priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
+                priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
+                if (!priv->int_buffer) {
+                        dev_err(&priv->udev->dev, "out of memory\n");
+                        goto error;
+                }
+
+                priv->int_address = endpoint->bEndpointAddress;
+                priv->bInterval = endpoint->bInterval;
+
+                /* set up our int urb */
+                usb_fill_int_urb(priv->int_urb, priv->udev,
+                                 usb_rcvintpipe(priv->udev,
+                                                endpoint->bEndpointAddress),
+                                 priv->int_buffer, priv->buffer_size,
+                                 symbol_int_callback, priv, priv->bInterval);
+
+                int_in_found = true;
+                break;
+                }
+
+        if (!int_in_found) {
+                dev_err(&priv->udev->dev,
+                        "Error - the proper endpoints were not found!\n");
+                goto error;
+        }
+
+        usb_set_serial_data(serial, priv);
+        return 0;
+
+error:
+        usb_free_urb(priv->int_urb);
+        kfree(priv->int_buffer);
+        kfree(priv);
+        return retval;
+}
+
+static void symbol_shutdown(struct usb_serial *serial)
+{
+        struct symbol_private *priv = usb_get_serial_data(serial);
+
+        dbg("%s", __func__);
+
+        usb_kill_urb(priv->int_urb);
+        usb_free_urb(priv->int_urb);
+        kfree(priv->int_buffer);
+        kfree(priv);
+        usb_set_serial_data(serial, NULL);
+}
+
+static struct usb_driver symbol_driver = {
+        .name =                 "symbol",
+        .probe =                usb_serial_probe,
+        .disconnect =           usb_serial_disconnect,
+        .id_table =             id_table,
+        .no_dynamic_id =        1,
+};
+
+static struct usb_serial_driver symbol_device = {
+        .driver = {
+                .owner =        THIS_MODULE,
+                .name =         "symbol",
+        },
+        .id_table =             id_table,
+        .usb_driver =           &symbol_driver,
+        .num_ports =            1,
+        .attach =               symbol_startup,
+        .open =                 symbol_open,
+        .close =                symbol_close,
+        .shutdown =             symbol_shutdown,
+        .throttle =             symbol_throttle,
+        .unthrottle =           symbol_unthrottle,
+};
+
+static int __init symbol_init(void)
+{
+        int retval;
+
+        retval = usb_serial_register(&symbol_device);
+        if (retval)
+                return retval;
+        retval = usb_register(&symbol_driver);
+        if (retval)
+                usb_serial_deregister(&symbol_device);
+        return retval;
+}
+
+static void __exit symbol_exit(void)
+{
+        usb_deregister(&symbol_driver);
+        usb_serial_deregister(&symbol_device);
+}
+
+module_init(symbol_init);
+module_exit(symbol_exit);
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");