xref: /linux/drivers/usb/serial/generic.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * USB Serial Converter Generic functions
3  *
4  * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License version
8  *	2 as published by the Free Software Foundation.
9  *
10  */
11 
12 #include <linux/config.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/tty.h>
17 #include <linux/tty_flip.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/usb.h>
21 #include <asm/uaccess.h>
22 #include "usb-serial.h"
23 
24 static int debug;
25 
26 #ifdef CONFIG_USB_SERIAL_GENERIC
27 static __u16 vendor  = 0x05f9;
28 static __u16 product = 0xffff;
29 
30 module_param(vendor, ushort, 0);
31 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
32 
33 module_param(product, ushort, 0);
34 MODULE_PARM_DESC(product, "User specified USB idProduct");
35 
36 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
37 
38 /* All of the device info needed for the Generic Serial Converter */
39 struct usb_serial_driver usb_serial_generic_device = {
40 	.driver = {
41 		.owner =	THIS_MODULE,
42 		.name =		"generic",
43 	},
44 	.id_table =		generic_device_ids,
45 	.num_interrupt_in =	NUM_DONT_CARE,
46 	.num_bulk_in =		NUM_DONT_CARE,
47 	.num_bulk_out =		NUM_DONT_CARE,
48 	.num_ports =		1,
49 	.shutdown =		usb_serial_generic_shutdown,
50 };
51 
52 /* we want to look at all devices, as the vendor/product id can change
53  * depending on the command line argument */
54 static struct usb_device_id generic_serial_ids[] = {
55 	{.driver_info = 42},
56 	{}
57 };
58 
59 static int generic_probe(struct usb_interface *interface,
60 			       const struct usb_device_id *id)
61 {
62 	const struct usb_device_id *id_pattern;
63 
64 	id_pattern = usb_match_id(interface, generic_device_ids);
65 	if (id_pattern != NULL)
66 		return usb_serial_probe(interface, id);
67 	return -ENODEV;
68 }
69 
70 static struct usb_driver generic_driver = {
71 	.name =		"usbserial_generic",
72 	.probe =	generic_probe,
73 	.disconnect =	usb_serial_disconnect,
74 	.id_table =	generic_serial_ids,
75 	.no_dynamic_id = 	1,
76 };
77 #endif
78 
79 int usb_serial_generic_register (int _debug)
80 {
81 	int retval = 0;
82 
83 	debug = _debug;
84 #ifdef CONFIG_USB_SERIAL_GENERIC
85 	generic_device_ids[0].idVendor = vendor;
86 	generic_device_ids[0].idProduct = product;
87 	generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
88 
89 	/* register our generic driver with ourselves */
90 	retval = usb_serial_register (&usb_serial_generic_device);
91 	if (retval)
92 		goto exit;
93 	retval = usb_register(&generic_driver);
94 	if (retval)
95 		usb_serial_deregister(&usb_serial_generic_device);
96 exit:
97 #endif
98 	return retval;
99 }
100 
101 void usb_serial_generic_deregister (void)
102 {
103 #ifdef CONFIG_USB_SERIAL_GENERIC
104 	/* remove our generic driver */
105 	usb_deregister(&generic_driver);
106 	usb_serial_deregister (&usb_serial_generic_device);
107 #endif
108 }
109 
110 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
111 {
112 	struct usb_serial *serial = port->serial;
113 	int result = 0;
114 
115 	dbg("%s - port %d", __FUNCTION__, port->number);
116 
117 	/* force low_latency on so that our tty_push actually forces the data through,
118 	   otherwise it is scheduled, and with high data rates (like with OHCI) data
119 	   can get lost. */
120 	if (port->tty)
121 		port->tty->low_latency = 1;
122 
123 	/* if we have a bulk interrupt, start reading from it */
124 	if (serial->num_bulk_in) {
125 		/* Start reading from the device */
126 		usb_fill_bulk_urb (port->read_urb, serial->dev,
127 				   usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
128 				   port->read_urb->transfer_buffer,
129 				   port->read_urb->transfer_buffer_length,
130 				   ((serial->type->read_bulk_callback) ?
131 				     serial->type->read_bulk_callback :
132 				     usb_serial_generic_read_bulk_callback),
133 				   port);
134 		result = usb_submit_urb(port->read_urb, GFP_KERNEL);
135 		if (result)
136 			dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
137 	}
138 
139 	return result;
140 }
141 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
142 
143 static void generic_cleanup (struct usb_serial_port *port)
144 {
145 	struct usb_serial *serial = port->serial;
146 
147 	dbg("%s - port %d", __FUNCTION__, port->number);
148 
149 	if (serial->dev) {
150 		/* shutdown any bulk reads that might be going on */
151 		if (serial->num_bulk_out)
152 			usb_kill_urb(port->write_urb);
153 		if (serial->num_bulk_in)
154 			usb_kill_urb(port->read_urb);
155 	}
156 }
157 
158 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
159 {
160 	dbg("%s - port %d", __FUNCTION__, port->number);
161 	generic_cleanup (port);
162 }
163 
164 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
165 {
166 	struct usb_serial *serial = port->serial;
167 	int result;
168 	unsigned char *data;
169 
170 	dbg("%s - port %d", __FUNCTION__, port->number);
171 
172 	if (count == 0) {
173 		dbg("%s - write request of 0 bytes", __FUNCTION__);
174 		return (0);
175 	}
176 
177 	/* only do something if we have a bulk out endpoint */
178 	if (serial->num_bulk_out) {
179 		spin_lock(&port->lock);
180 		if (port->write_urb_busy) {
181 			spin_unlock(&port->lock);
182 			dbg("%s - already writing", __FUNCTION__);
183 			return 0;
184 		}
185 		port->write_urb_busy = 1;
186 		spin_unlock(&port->lock);
187 
188 		count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
189 
190 		memcpy (port->write_urb->transfer_buffer, buf, count);
191 		data = port->write_urb->transfer_buffer;
192 		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
193 
194 		/* set up our urb */
195 		usb_fill_bulk_urb (port->write_urb, serial->dev,
196 				   usb_sndbulkpipe (serial->dev,
197 						    port->bulk_out_endpointAddress),
198 				   port->write_urb->transfer_buffer, count,
199 				   ((serial->type->write_bulk_callback) ?
200 				     serial->type->write_bulk_callback :
201 				     usb_serial_generic_write_bulk_callback), port);
202 
203 		/* send the data out the bulk port */
204 		port->write_urb_busy = 1;
205 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
206 		if (result) {
207 			dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
208 			/* don't have to grab the lock here, as we will retry if != 0 */
209 			port->write_urb_busy = 0;
210 		} else
211 			result = count;
212 
213 		return result;
214 	}
215 
216 	/* no bulk out, so return 0 bytes written */
217 	return 0;
218 }
219 
220 int usb_serial_generic_write_room (struct usb_serial_port *port)
221 {
222 	struct usb_serial *serial = port->serial;
223 	int room = 0;
224 
225 	dbg("%s - port %d", __FUNCTION__, port->number);
226 
227 	if (serial->num_bulk_out) {
228 		if (!(port->write_urb_busy))
229 			room = port->bulk_out_size;
230 	}
231 
232 	dbg("%s - returns %d", __FUNCTION__, room);
233 	return (room);
234 }
235 
236 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
237 {
238 	struct usb_serial *serial = port->serial;
239 	int chars = 0;
240 
241 	dbg("%s - port %d", __FUNCTION__, port->number);
242 
243 	if (serial->num_bulk_out) {
244 		if (port->write_urb_busy)
245 			chars = port->write_urb->transfer_buffer_length;
246 	}
247 
248 	dbg("%s - returns %d", __FUNCTION__, chars);
249 	return (chars);
250 }
251 
252 void usb_serial_generic_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
253 {
254 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
255 	struct usb_serial *serial = port->serial;
256 	struct tty_struct *tty;
257 	unsigned char *data = urb->transfer_buffer;
258 	int result;
259 
260 	dbg("%s - port %d", __FUNCTION__, port->number);
261 
262 	if (urb->status) {
263 		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
264 		return;
265 	}
266 
267 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
268 
269 	tty = port->tty;
270 	if (tty && urb->actual_length) {
271 		tty_buffer_request_room(tty, urb->actual_length);
272 		tty_insert_flip_string(tty, data, urb->actual_length);
273 	  	tty_flip_buffer_push(tty);
274 	}
275 
276 	/* Continue trying to always read  */
277 	usb_fill_bulk_urb (port->read_urb, serial->dev,
278 			   usb_rcvbulkpipe (serial->dev,
279 				   	    port->bulk_in_endpointAddress),
280 			   port->read_urb->transfer_buffer,
281 			   port->read_urb->transfer_buffer_length,
282 			   ((serial->type->read_bulk_callback) ?
283 			     serial->type->read_bulk_callback :
284 			     usb_serial_generic_read_bulk_callback), port);
285 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
286 	if (result)
287 		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
288 }
289 
290 void usb_serial_generic_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
291 {
292 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
293 
294 	dbg("%s - port %d", __FUNCTION__, port->number);
295 
296 	port->write_urb_busy = 0;
297 	if (urb->status) {
298 		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
299 		return;
300 	}
301 
302 	usb_serial_port_softint(port);
303 }
304 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
305 
306 void usb_serial_generic_shutdown (struct usb_serial *serial)
307 {
308 	int i;
309 
310 	dbg("%s", __FUNCTION__);
311 
312 	/* stop reads and writes on all ports */
313 	for (i=0; i < serial->num_ports; ++i) {
314 		generic_cleanup(serial->port[i]);
315 	}
316 }
317 
318