xref: /openbmc/linux/drivers/usb/serial/generic.c (revision 87c2ce3b)
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 
142 static void generic_cleanup (struct usb_serial_port *port)
143 {
144 	struct usb_serial *serial = port->serial;
145 
146 	dbg("%s - port %d", __FUNCTION__, port->number);
147 
148 	if (serial->dev) {
149 		/* shutdown any bulk reads that might be going on */
150 		if (serial->num_bulk_out)
151 			usb_kill_urb(port->write_urb);
152 		if (serial->num_bulk_in)
153 			usb_kill_urb(port->read_urb);
154 	}
155 }
156 
157 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
158 {
159 	dbg("%s - port %d", __FUNCTION__, port->number);
160 	generic_cleanup (port);
161 }
162 
163 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
164 {
165 	struct usb_serial *serial = port->serial;
166 	int result;
167 	unsigned char *data;
168 
169 	dbg("%s - port %d", __FUNCTION__, port->number);
170 
171 	if (count == 0) {
172 		dbg("%s - write request of 0 bytes", __FUNCTION__);
173 		return (0);
174 	}
175 
176 	/* only do something if we have a bulk out endpoint */
177 	if (serial->num_bulk_out) {
178 		spin_lock(&port->lock);
179 		if (port->write_urb_busy) {
180 			spin_unlock(&port->lock);
181 			dbg("%s - already writing", __FUNCTION__);
182 			return 0;
183 		}
184 		port->write_urb_busy = 1;
185 		spin_unlock(&port->lock);
186 
187 		count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
188 
189 		memcpy (port->write_urb->transfer_buffer, buf, count);
190 		data = port->write_urb->transfer_buffer;
191 		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
192 
193 		/* set up our urb */
194 		usb_fill_bulk_urb (port->write_urb, serial->dev,
195 				   usb_sndbulkpipe (serial->dev,
196 						    port->bulk_out_endpointAddress),
197 				   port->write_urb->transfer_buffer, count,
198 				   ((serial->type->write_bulk_callback) ?
199 				     serial->type->write_bulk_callback :
200 				     usb_serial_generic_write_bulk_callback), port);
201 
202 		/* send the data out the bulk port */
203 		port->write_urb_busy = 1;
204 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
205 		if (result) {
206 			dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
207 			/* don't have to grab the lock here, as we will retry if != 0 */
208 			port->write_urb_busy = 0;
209 		} else
210 			result = count;
211 
212 		return result;
213 	}
214 
215 	/* no bulk out, so return 0 bytes written */
216 	return 0;
217 }
218 
219 int usb_serial_generic_write_room (struct usb_serial_port *port)
220 {
221 	struct usb_serial *serial = port->serial;
222 	int room = 0;
223 
224 	dbg("%s - port %d", __FUNCTION__, port->number);
225 
226 	if (serial->num_bulk_out) {
227 		if (!(port->write_urb_busy))
228 			room = port->bulk_out_size;
229 	}
230 
231 	dbg("%s - returns %d", __FUNCTION__, room);
232 	return (room);
233 }
234 
235 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
236 {
237 	struct usb_serial *serial = port->serial;
238 	int chars = 0;
239 
240 	dbg("%s - port %d", __FUNCTION__, port->number);
241 
242 	if (serial->num_bulk_out) {
243 		if (port->write_urb_busy)
244 			chars = port->write_urb->transfer_buffer_length;
245 	}
246 
247 	dbg("%s - returns %d", __FUNCTION__, chars);
248 	return (chars);
249 }
250 
251 void usb_serial_generic_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
252 {
253 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
254 	struct usb_serial *serial = port->serial;
255 	struct tty_struct *tty;
256 	unsigned char *data = urb->transfer_buffer;
257 	int i;
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 		for (i = 0; i < urb->actual_length ; ++i) {
272 			/* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
273 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
274 				tty_flip_buffer_push(tty);
275 			}
276 			/* this doesn't actually push the data through unless tty->low_latency is set */
277 			tty_insert_flip_char(tty, data[i], 0);
278 		}
279 	  	tty_flip_buffer_push(tty);
280 	}
281 
282 	/* Continue trying to always read  */
283 	usb_fill_bulk_urb (port->read_urb, serial->dev,
284 			   usb_rcvbulkpipe (serial->dev,
285 				   	    port->bulk_in_endpointAddress),
286 			   port->read_urb->transfer_buffer,
287 			   port->read_urb->transfer_buffer_length,
288 			   ((serial->type->read_bulk_callback) ?
289 			     serial->type->read_bulk_callback :
290 			     usb_serial_generic_read_bulk_callback), port);
291 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
292 	if (result)
293 		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
294 }
295 
296 void usb_serial_generic_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
297 {
298 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
299 
300 	dbg("%s - port %d", __FUNCTION__, port->number);
301 
302 	port->write_urb_busy = 0;
303 	if (urb->status) {
304 		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
305 		return;
306 	}
307 
308 	usb_serial_port_softint((void *)port);
309 
310 	schedule_work(&port->work);
311 }
312 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
313 
314 void usb_serial_generic_shutdown (struct usb_serial *serial)
315 {
316 	int i;
317 
318 	dbg("%s", __FUNCTION__);
319 
320 	/* stop reads and writes on all ports */
321 	for (i=0; i < serial->num_ports; ++i) {
322 		generic_cleanup(serial->port[i]);
323 	}
324 }
325 
326