1 /* 2 * Symbol USB barcode to serial driver 3 * 4 * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de> 5 * Copyright (C) 2009 Novell Inc. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 9 * 2 as published by the Free Software Foundation. 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/tty.h> 15 #include <linux/tty_driver.h> 16 #include <linux/tty_flip.h> 17 #include <linux/module.h> 18 #include <linux/usb.h> 19 #include <linux/usb/serial.h> 20 #include <linux/uaccess.h> 21 22 static int debug; 23 24 static struct usb_device_id id_table[] = { 25 { USB_DEVICE(0x05e0, 0x0600) }, 26 { }, 27 }; 28 MODULE_DEVICE_TABLE(usb, id_table); 29 30 /* This structure holds all of the individual device information */ 31 struct symbol_private { 32 struct usb_device *udev; 33 struct usb_serial *serial; 34 struct usb_serial_port *port; 35 unsigned char *int_buffer; 36 struct urb *int_urb; 37 int buffer_size; 38 u8 bInterval; 39 u8 int_address; 40 spinlock_t lock; /* protects the following flags */ 41 bool throttled; 42 bool actually_throttled; 43 bool rts; 44 }; 45 46 static void symbol_int_callback(struct urb *urb) 47 { 48 struct symbol_private *priv = urb->context; 49 unsigned char *data = urb->transfer_buffer; 50 struct usb_serial_port *port = priv->port; 51 int status = urb->status; 52 struct tty_struct *tty; 53 int result; 54 int available_room = 0; 55 int data_length; 56 57 dbg("%s - port %d", __func__, port->number); 58 59 switch (status) { 60 case 0: 61 /* success */ 62 break; 63 case -ECONNRESET: 64 case -ENOENT: 65 case -ESHUTDOWN: 66 /* this urb is terminated, clean up */ 67 dbg("%s - urb shutting down with status: %d", 68 __func__, status); 69 return; 70 default: 71 dbg("%s - nonzero urb status received: %d", 72 __func__, status); 73 goto exit; 74 } 75 76 usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length, 77 data); 78 79 if (urb->actual_length > 1) { 80 data_length = urb->actual_length - 1; 81 82 /* 83 * Data from the device comes with a 1 byte header: 84 * 85 * <size of data>data... 86 * This is real data to be sent to the tty layer 87 * we pretty much just ignore the size and send everything 88 * else to the tty layer. 89 */ 90 tty = tty_port_tty_get(&port->port); 91 if (tty) { 92 available_room = tty_buffer_request_room(tty, 93 data_length); 94 if (available_room) { 95 tty_insert_flip_string(tty, &data[1], 96 available_room); 97 tty_flip_buffer_push(tty); 98 } 99 tty_kref_put(tty); 100 } 101 } else { 102 dev_dbg(&priv->udev->dev, 103 "Improper ammount of data received from the device, " 104 "%d bytes", urb->actual_length); 105 } 106 107 exit: 108 spin_lock(&priv->lock); 109 110 /* Continue trying to always read if we should */ 111 if (!priv->throttled) { 112 usb_fill_int_urb(priv->int_urb, priv->udev, 113 usb_rcvintpipe(priv->udev, 114 priv->int_address), 115 priv->int_buffer, priv->buffer_size, 116 symbol_int_callback, priv, priv->bInterval); 117 result = usb_submit_urb(priv->int_urb, GFP_ATOMIC); 118 if (result) 119 dev_err(&port->dev, 120 "%s - failed resubmitting read urb, error %d\n", 121 __func__, result); 122 } else 123 priv->actually_throttled = true; 124 spin_unlock(&priv->lock); 125 } 126 127 static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port, 128 struct file *filp) 129 { 130 struct symbol_private *priv = usb_get_serial_data(port->serial); 131 unsigned long flags; 132 int result = 0; 133 134 dbg("%s - port %d", __func__, port->number); 135 136 spin_lock_irqsave(&priv->lock, flags); 137 priv->throttled = false; 138 priv->actually_throttled = false; 139 priv->port = port; 140 spin_unlock_irqrestore(&priv->lock, flags); 141 142 /* Start reading from the device */ 143 usb_fill_int_urb(priv->int_urb, priv->udev, 144 usb_rcvintpipe(priv->udev, priv->int_address), 145 priv->int_buffer, priv->buffer_size, 146 symbol_int_callback, priv, priv->bInterval); 147 result = usb_submit_urb(priv->int_urb, GFP_KERNEL); 148 if (result) 149 dev_err(&port->dev, 150 "%s - failed resubmitting read urb, error %d\n", 151 __func__, result); 152 return result; 153 } 154 155 static void symbol_close(struct tty_struct *tty, struct usb_serial_port *port, 156 struct file *filp) 157 { 158 struct symbol_private *priv = usb_get_serial_data(port->serial); 159 160 dbg("%s - port %d", __func__, port->number); 161 162 /* shutdown our urbs */ 163 usb_kill_urb(priv->int_urb); 164 } 165 166 static void symbol_throttle(struct tty_struct *tty) 167 { 168 struct usb_serial_port *port = tty->driver_data; 169 struct symbol_private *priv = usb_get_serial_data(port->serial); 170 unsigned long flags; 171 172 dbg("%s - port %d", __func__, port->number); 173 spin_lock_irqsave(&priv->lock, flags); 174 priv->throttled = true; 175 spin_unlock_irqrestore(&priv->lock, flags); 176 } 177 178 static void symbol_unthrottle(struct tty_struct *tty) 179 { 180 struct usb_serial_port *port = tty->driver_data; 181 struct symbol_private *priv = usb_get_serial_data(port->serial); 182 unsigned long flags; 183 int result; 184 185 dbg("%s - port %d", __func__, port->number); 186 187 spin_lock_irqsave(&priv->lock, flags); 188 priv->throttled = false; 189 priv->actually_throttled = false; 190 spin_unlock_irqrestore(&priv->lock, flags); 191 192 priv->int_urb->dev = port->serial->dev; 193 result = usb_submit_urb(priv->int_urb, GFP_ATOMIC); 194 if (result) 195 dev_err(&port->dev, 196 "%s - failed submitting read urb, error %d\n", 197 __func__, result); 198 } 199 200 static int symbol_startup(struct usb_serial *serial) 201 { 202 struct symbol_private *priv; 203 struct usb_host_interface *intf; 204 int i; 205 int retval = -ENOMEM; 206 bool int_in_found = false; 207 208 /* create our private serial structure */ 209 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 210 if (priv == NULL) { 211 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__); 212 return -ENOMEM; 213 } 214 spin_lock_init(&priv->lock); 215 priv->serial = serial; 216 priv->port = serial->port[0]; 217 priv->udev = serial->dev; 218 219 /* find our interrupt endpoint */ 220 intf = serial->interface->altsetting; 221 for (i = 0; i < intf->desc.bNumEndpoints; ++i) { 222 struct usb_endpoint_descriptor *endpoint; 223 224 endpoint = &intf->endpoint[i].desc; 225 if (!usb_endpoint_is_int_in(endpoint)) 226 continue; 227 228 priv->int_urb = usb_alloc_urb(0, GFP_KERNEL); 229 if (!priv->int_urb) { 230 dev_err(&priv->udev->dev, "out of memory\n"); 231 goto error; 232 } 233 234 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2; 235 priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL); 236 if (!priv->int_buffer) { 237 dev_err(&priv->udev->dev, "out of memory\n"); 238 goto error; 239 } 240 241 priv->int_address = endpoint->bEndpointAddress; 242 priv->bInterval = endpoint->bInterval; 243 244 /* set up our int urb */ 245 usb_fill_int_urb(priv->int_urb, priv->udev, 246 usb_rcvintpipe(priv->udev, 247 endpoint->bEndpointAddress), 248 priv->int_buffer, priv->buffer_size, 249 symbol_int_callback, priv, priv->bInterval); 250 251 int_in_found = true; 252 break; 253 } 254 255 if (!int_in_found) { 256 dev_err(&priv->udev->dev, 257 "Error - the proper endpoints were not found!\n"); 258 goto error; 259 } 260 261 usb_set_serial_data(serial, priv); 262 return 0; 263 264 error: 265 usb_free_urb(priv->int_urb); 266 kfree(priv->int_buffer); 267 kfree(priv); 268 return retval; 269 } 270 271 static void symbol_shutdown(struct usb_serial *serial) 272 { 273 struct symbol_private *priv = usb_get_serial_data(serial); 274 275 dbg("%s", __func__); 276 277 usb_kill_urb(priv->int_urb); 278 usb_free_urb(priv->int_urb); 279 kfree(priv->int_buffer); 280 kfree(priv); 281 usb_set_serial_data(serial, NULL); 282 } 283 284 static struct usb_driver symbol_driver = { 285 .name = "symbol", 286 .probe = usb_serial_probe, 287 .disconnect = usb_serial_disconnect, 288 .id_table = id_table, 289 .no_dynamic_id = 1, 290 }; 291 292 static struct usb_serial_driver symbol_device = { 293 .driver = { 294 .owner = THIS_MODULE, 295 .name = "symbol", 296 }, 297 .id_table = id_table, 298 .usb_driver = &symbol_driver, 299 .num_ports = 1, 300 .attach = symbol_startup, 301 .open = symbol_open, 302 .close = symbol_close, 303 .shutdown = symbol_shutdown, 304 .throttle = symbol_throttle, 305 .unthrottle = symbol_unthrottle, 306 }; 307 308 static int __init symbol_init(void) 309 { 310 int retval; 311 312 retval = usb_serial_register(&symbol_device); 313 if (retval) 314 return retval; 315 retval = usb_register(&symbol_driver); 316 if (retval) 317 usb_serial_deregister(&symbol_device); 318 return retval; 319 } 320 321 static void __exit symbol_exit(void) 322 { 323 usb_deregister(&symbol_driver); 324 usb_serial_deregister(&symbol_device); 325 } 326 327 module_init(symbol_init); 328 module_exit(symbol_exit); 329 MODULE_LICENSE("GPL"); 330 331 module_param(debug, bool, S_IRUGO | S_IWUSR); 332 MODULE_PARM_DESC(debug, "Debug enabled or not"); 333