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 { 129 struct symbol_private *priv = usb_get_serial_data(port->serial); 130 unsigned long flags; 131 int result = 0; 132 133 dbg("%s - port %d", __func__, port->number); 134 135 spin_lock_irqsave(&priv->lock, flags); 136 priv->throttled = false; 137 priv->actually_throttled = false; 138 priv->port = port; 139 spin_unlock_irqrestore(&priv->lock, flags); 140 141 /* Start reading from the device */ 142 usb_fill_int_urb(priv->int_urb, priv->udev, 143 usb_rcvintpipe(priv->udev, priv->int_address), 144 priv->int_buffer, priv->buffer_size, 145 symbol_int_callback, priv, priv->bInterval); 146 result = usb_submit_urb(priv->int_urb, GFP_KERNEL); 147 if (result) 148 dev_err(&port->dev, 149 "%s - failed resubmitting read urb, error %d\n", 150 __func__, result); 151 return result; 152 } 153 154 static void symbol_close(struct usb_serial_port *port) 155 { 156 struct symbol_private *priv = usb_get_serial_data(port->serial); 157 158 dbg("%s - port %d", __func__, port->number); 159 160 /* shutdown our urbs */ 161 usb_kill_urb(priv->int_urb); 162 } 163 164 static void symbol_throttle(struct tty_struct *tty) 165 { 166 struct usb_serial_port *port = tty->driver_data; 167 struct symbol_private *priv = usb_get_serial_data(port->serial); 168 unsigned long flags; 169 170 dbg("%s - port %d", __func__, port->number); 171 spin_lock_irqsave(&priv->lock, flags); 172 priv->throttled = true; 173 spin_unlock_irqrestore(&priv->lock, flags); 174 } 175 176 static void symbol_unthrottle(struct tty_struct *tty) 177 { 178 struct usb_serial_port *port = tty->driver_data; 179 struct symbol_private *priv = usb_get_serial_data(port->serial); 180 unsigned long flags; 181 int result; 182 183 dbg("%s - port %d", __func__, port->number); 184 185 spin_lock_irqsave(&priv->lock, flags); 186 priv->throttled = false; 187 priv->actually_throttled = false; 188 spin_unlock_irqrestore(&priv->lock, flags); 189 190 priv->int_urb->dev = port->serial->dev; 191 result = usb_submit_urb(priv->int_urb, GFP_ATOMIC); 192 if (result) 193 dev_err(&port->dev, 194 "%s - failed submitting read urb, error %d\n", 195 __func__, result); 196 } 197 198 static int symbol_startup(struct usb_serial *serial) 199 { 200 struct symbol_private *priv; 201 struct usb_host_interface *intf; 202 int i; 203 int retval = -ENOMEM; 204 bool int_in_found = false; 205 206 /* create our private serial structure */ 207 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 208 if (priv == NULL) { 209 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__); 210 return -ENOMEM; 211 } 212 spin_lock_init(&priv->lock); 213 priv->serial = serial; 214 priv->port = serial->port[0]; 215 priv->udev = serial->dev; 216 217 /* find our interrupt endpoint */ 218 intf = serial->interface->altsetting; 219 for (i = 0; i < intf->desc.bNumEndpoints; ++i) { 220 struct usb_endpoint_descriptor *endpoint; 221 222 endpoint = &intf->endpoint[i].desc; 223 if (!usb_endpoint_is_int_in(endpoint)) 224 continue; 225 226 priv->int_urb = usb_alloc_urb(0, GFP_KERNEL); 227 if (!priv->int_urb) { 228 dev_err(&priv->udev->dev, "out of memory\n"); 229 goto error; 230 } 231 232 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2; 233 priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL); 234 if (!priv->int_buffer) { 235 dev_err(&priv->udev->dev, "out of memory\n"); 236 goto error; 237 } 238 239 priv->int_address = endpoint->bEndpointAddress; 240 priv->bInterval = endpoint->bInterval; 241 242 /* set up our int urb */ 243 usb_fill_int_urb(priv->int_urb, priv->udev, 244 usb_rcvintpipe(priv->udev, 245 endpoint->bEndpointAddress), 246 priv->int_buffer, priv->buffer_size, 247 symbol_int_callback, priv, priv->bInterval); 248 249 int_in_found = true; 250 break; 251 } 252 253 if (!int_in_found) { 254 dev_err(&priv->udev->dev, 255 "Error - the proper endpoints were not found!\n"); 256 goto error; 257 } 258 259 usb_set_serial_data(serial, priv); 260 return 0; 261 262 error: 263 usb_free_urb(priv->int_urb); 264 kfree(priv->int_buffer); 265 kfree(priv); 266 return retval; 267 } 268 269 static void symbol_disconnect(struct usb_serial *serial) 270 { 271 struct symbol_private *priv = usb_get_serial_data(serial); 272 273 dbg("%s", __func__); 274 275 usb_kill_urb(priv->int_urb); 276 usb_free_urb(priv->int_urb); 277 } 278 279 static void symbol_release(struct usb_serial *serial) 280 { 281 struct symbol_private *priv = usb_get_serial_data(serial); 282 283 dbg("%s", __func__); 284 285 kfree(priv->int_buffer); 286 kfree(priv); 287 } 288 289 static struct usb_driver symbol_driver = { 290 .name = "symbol", 291 .probe = usb_serial_probe, 292 .disconnect = usb_serial_disconnect, 293 .id_table = id_table, 294 .no_dynamic_id = 1, 295 }; 296 297 static struct usb_serial_driver symbol_device = { 298 .driver = { 299 .owner = THIS_MODULE, 300 .name = "symbol", 301 }, 302 .id_table = id_table, 303 .usb_driver = &symbol_driver, 304 .num_ports = 1, 305 .attach = symbol_startup, 306 .open = symbol_open, 307 .close = symbol_close, 308 .disconnect = symbol_disconnect, 309 .release = symbol_release, 310 .throttle = symbol_throttle, 311 .unthrottle = symbol_unthrottle, 312 }; 313 314 static int __init symbol_init(void) 315 { 316 int retval; 317 318 retval = usb_serial_register(&symbol_device); 319 if (retval) 320 return retval; 321 retval = usb_register(&symbol_driver); 322 if (retval) 323 usb_serial_deregister(&symbol_device); 324 return retval; 325 } 326 327 static void __exit symbol_exit(void) 328 { 329 usb_deregister(&symbol_driver); 330 usb_serial_deregister(&symbol_device); 331 } 332 333 module_init(symbol_init); 334 module_exit(symbol_exit); 335 MODULE_LICENSE("GPL"); 336 337 module_param(debug, bool, S_IRUGO | S_IWUSR); 338 MODULE_PARM_DESC(debug, "Debug enabled or not"); 339