xref: /linux/drivers/usb/serial/generic.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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_device_type usb_serial_generic_device = {
40 	.owner =		THIS_MODULE,
41 	.name =			"Generic",
42 	.short_name =		"generic",
43 	.id_table =		generic_device_ids,
44 	.num_interrupt_in =	NUM_DONT_CARE,
45 	.num_bulk_in =		NUM_DONT_CARE,
46 	.num_bulk_out =		NUM_DONT_CARE,
47 	.num_ports =		1,
48 	.shutdown =		usb_serial_generic_shutdown,
49 };
50 
51 /* we want to look at all devices, as the vendor/product id can change
52  * depending on the command line argument */
53 static struct usb_device_id generic_serial_ids[] = {
54 	{.driver_info = 42},
55 	{}
56 };
57 
58 static int generic_probe(struct usb_interface *interface,
59 			       const struct usb_device_id *id)
60 {
61 	const struct usb_device_id *id_pattern;
62 
63 	id_pattern = usb_match_id(interface, generic_device_ids);
64 	if (id_pattern != NULL)
65 		return usb_serial_probe(interface, id);
66 	return -ENODEV;
67 }
68 
69 static struct usb_driver generic_driver = {
70 	.owner =	THIS_MODULE,
71 	.name =		"usbserial_generic",
72 	.probe =	generic_probe,
73 	.disconnect =	usb_serial_disconnect,
74 	.id_table =	generic_serial_ids,
75 };
76 #endif
77 
78 int usb_serial_generic_register (int _debug)
79 {
80 	int retval = 0;
81 
82 	debug = _debug;
83 #ifdef CONFIG_USB_SERIAL_GENERIC
84 	generic_device_ids[0].idVendor = vendor;
85 	generic_device_ids[0].idProduct = product;
86 	generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
87 
88 	/* register our generic driver with ourselves */
89 	retval = usb_serial_register (&usb_serial_generic_device);
90 	if (retval)
91 		goto exit;
92 	retval = usb_register(&generic_driver);
93 	if (retval)
94 		usb_serial_deregister(&usb_serial_generic_device);
95 exit:
96 #endif
97 	return retval;
98 }
99 
100 void usb_serial_generic_deregister (void)
101 {
102 #ifdef CONFIG_USB_SERIAL_GENERIC
103 	/* remove our generic driver */
104 	usb_deregister(&generic_driver);
105 	usb_serial_deregister (&usb_serial_generic_device);
106 #endif
107 }
108 
109 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
110 {
111 	struct usb_serial *serial = port->serial;
112 	int result = 0;
113 
114 	dbg("%s - port %d", __FUNCTION__, port->number);
115 
116 	/* force low_latency on so that our tty_push actually forces the data through,
117 	   otherwise it is scheduled, and with high data rates (like with OHCI) data
118 	   can get lost. */
119 	if (port->tty)
120 		port->tty->low_latency = 1;
121 
122 	/* if we have a bulk interrupt, start reading from it */
123 	if (serial->num_bulk_in) {
124 		/* Start reading from the device */
125 		usb_fill_bulk_urb (port->read_urb, serial->dev,
126 				   usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
127 				   port->read_urb->transfer_buffer,
128 				   port->read_urb->transfer_buffer_length,
129 				   ((serial->type->read_bulk_callback) ?
130 				     serial->type->read_bulk_callback :
131 				     usb_serial_generic_read_bulk_callback),
132 				   port);
133 		result = usb_submit_urb(port->read_urb, GFP_KERNEL);
134 		if (result)
135 			dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
136 	}
137 
138 	return result;
139 }
140 
141 static void generic_cleanup (struct usb_serial_port *port)
142 {
143 	struct usb_serial *serial = port->serial;
144 
145 	dbg("%s - port %d", __FUNCTION__, port->number);
146 
147 	if (serial->dev) {
148 		/* shutdown any bulk reads that might be going on */
149 		if (serial->num_bulk_out)
150 			usb_kill_urb(port->write_urb);
151 		if (serial->num_bulk_in)
152 			usb_kill_urb(port->read_urb);
153 	}
154 }
155 
156 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
157 {
158 	dbg("%s - port %d", __FUNCTION__, port->number);
159 	generic_cleanup (port);
160 }
161 
162 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
163 {
164 	struct usb_serial *serial = port->serial;
165 	int result;
166 	unsigned char *data;
167 
168 	dbg("%s - port %d", __FUNCTION__, port->number);
169 
170 	if (count == 0) {
171 		dbg("%s - write request of 0 bytes", __FUNCTION__);
172 		return (0);
173 	}
174 
175 	/* only do something if we have a bulk out endpoint */
176 	if (serial->num_bulk_out) {
177 		spin_lock(&port->lock);
178 		if (port->write_urb_busy) {
179 			spin_unlock(&port->lock);
180 			dbg("%s - already writing", __FUNCTION__);
181 			return 0;
182 		}
183 		port->write_urb_busy = 1;
184 		spin_unlock(&port->lock);
185 
186 		count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
187 
188 		memcpy (port->write_urb->transfer_buffer, buf, count);
189 		data = port->write_urb->transfer_buffer;
190 		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
191 
192 		/* set up our urb */
193 		usb_fill_bulk_urb (port->write_urb, serial->dev,
194 				   usb_sndbulkpipe (serial->dev,
195 						    port->bulk_out_endpointAddress),
196 				   port->write_urb->transfer_buffer, count,
197 				   ((serial->type->write_bulk_callback) ?
198 				     serial->type->write_bulk_callback :
199 				     usb_serial_generic_write_bulk_callback), port);
200 
201 		/* send the data out the bulk port */
202 		port->write_urb_busy = 1;
203 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
204 		if (result) {
205 			dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
206 			/* don't have to grab the lock here, as we will retry if != 0 */
207 			port->write_urb_busy = 0;
208 		} else
209 			result = count;
210 
211 		return result;
212 	}
213 
214 	/* no bulk out, so return 0 bytes written */
215 	return 0;
216 }
217 
218 int usb_serial_generic_write_room (struct usb_serial_port *port)
219 {
220 	struct usb_serial *serial = port->serial;
221 	int room = 0;
222 
223 	dbg("%s - port %d", __FUNCTION__, port->number);
224 
225 	if (serial->num_bulk_out) {
226 		if (port->write_urb_busy)
227 			room = port->bulk_out_size;
228 	}
229 
230 	dbg("%s - returns %d", __FUNCTION__, room);
231 	return (room);
232 }
233 
234 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
235 {
236 	struct usb_serial *serial = port->serial;
237 	int chars = 0;
238 
239 	dbg("%s - port %d", __FUNCTION__, port->number);
240 
241 	if (serial->num_bulk_out) {
242 		if (port->write_urb_busy)
243 			chars = port->write_urb->transfer_buffer_length;
244 	}
245 
246 	dbg("%s - returns %d", __FUNCTION__, chars);
247 	return (chars);
248 }
249 
250 void usb_serial_generic_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
251 {
252 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
253 	struct usb_serial *serial = port->serial;
254 	struct tty_struct *tty;
255 	unsigned char *data = urb->transfer_buffer;
256 	int i;
257 	int result;
258 
259 	dbg("%s - port %d", __FUNCTION__, port->number);
260 
261 	if (urb->status) {
262 		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
263 		return;
264 	}
265 
266 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
267 
268 	tty = port->tty;
269 	if (tty && urb->actual_length) {
270 		for (i = 0; i < urb->actual_length ; ++i) {
271 			/* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
272 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
273 				tty_flip_buffer_push(tty);
274 			}
275 			/* this doesn't actually push the data through unless tty->low_latency is set */
276 			tty_insert_flip_char(tty, data[i], 0);
277 		}
278 	  	tty_flip_buffer_push(tty);
279 	}
280 
281 	/* Continue trying to always read  */
282 	usb_fill_bulk_urb (port->read_urb, serial->dev,
283 			   usb_rcvbulkpipe (serial->dev,
284 				   	    port->bulk_in_endpointAddress),
285 			   port->read_urb->transfer_buffer,
286 			   port->read_urb->transfer_buffer_length,
287 			   ((serial->type->read_bulk_callback) ?
288 			     serial->type->read_bulk_callback :
289 			     usb_serial_generic_read_bulk_callback), port);
290 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
291 	if (result)
292 		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
293 }
294 
295 void usb_serial_generic_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
296 {
297 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
298 
299 	dbg("%s - port %d", __FUNCTION__, port->number);
300 
301 	port->write_urb_busy = 0;
302 	if (urb->status) {
303 		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
304 		return;
305 	}
306 
307 	usb_serial_port_softint((void *)port);
308 
309 	schedule_work(&port->work);
310 }
311 
312 void usb_serial_generic_shutdown (struct usb_serial *serial)
313 {
314 	int i;
315 
316 	dbg("%s", __FUNCTION__);
317 
318 	/* stop reads and writes on all ports */
319 	for (i=0; i < serial->num_ports; ++i) {
320 		generic_cleanup(serial->port[i]);
321 	}
322 }
323 
324