xref: /openbmc/linux/drivers/usb/serial/generic.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 		if (port->write_urb->status == -EINPROGRESS) {
178 			dbg("%s - already writing", __FUNCTION__);
179 			return (0);
180 		}
181 
182 		count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
183 
184 		memcpy (port->write_urb->transfer_buffer, buf, count);
185 		data = port->write_urb->transfer_buffer;
186 		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
187 
188 		/* set up our urb */
189 		usb_fill_bulk_urb (port->write_urb, serial->dev,
190 				   usb_sndbulkpipe (serial->dev,
191 						    port->bulk_out_endpointAddress),
192 				   port->write_urb->transfer_buffer, count,
193 				   ((serial->type->write_bulk_callback) ?
194 				     serial->type->write_bulk_callback :
195 				     usb_serial_generic_write_bulk_callback), port);
196 
197 		/* send the data out the bulk port */
198 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
199 		if (result)
200 			dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
201 		else
202 			result = count;
203 
204 		return result;
205 	}
206 
207 	/* no bulk out, so return 0 bytes written */
208 	return (0);
209 }
210 
211 int usb_serial_generic_write_room (struct usb_serial_port *port)
212 {
213 	struct usb_serial *serial = port->serial;
214 	int room = 0;
215 
216 	dbg("%s - port %d", __FUNCTION__, port->number);
217 
218 	if (serial->num_bulk_out) {
219 		if (port->write_urb->status != -EINPROGRESS)
220 			room = port->bulk_out_size;
221 	}
222 
223 	dbg("%s - returns %d", __FUNCTION__, room);
224 	return (room);
225 }
226 
227 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
228 {
229 	struct usb_serial *serial = port->serial;
230 	int chars = 0;
231 
232 	dbg("%s - port %d", __FUNCTION__, port->number);
233 
234 	if (serial->num_bulk_out) {
235 		if (port->write_urb->status == -EINPROGRESS)
236 			chars = port->write_urb->transfer_buffer_length;
237 	}
238 
239 	dbg("%s - returns %d", __FUNCTION__, chars);
240 	return (chars);
241 }
242 
243 void usb_serial_generic_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
244 {
245 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
246 	struct usb_serial *serial = port->serial;
247 	struct tty_struct *tty;
248 	unsigned char *data = urb->transfer_buffer;
249 	int i;
250 	int result;
251 
252 	dbg("%s - port %d", __FUNCTION__, port->number);
253 
254 	if (urb->status) {
255 		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
256 		return;
257 	}
258 
259 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
260 
261 	tty = port->tty;
262 	if (tty && urb->actual_length) {
263 		for (i = 0; i < urb->actual_length ; ++i) {
264 			/* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
265 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
266 				tty_flip_buffer_push(tty);
267 			}
268 			/* this doesn't actually push the data through unless tty->low_latency is set */
269 			tty_insert_flip_char(tty, data[i], 0);
270 		}
271 	  	tty_flip_buffer_push(tty);
272 	}
273 
274 	/* Continue trying to always read  */
275 	usb_fill_bulk_urb (port->read_urb, serial->dev,
276 			   usb_rcvbulkpipe (serial->dev,
277 				   	    port->bulk_in_endpointAddress),
278 			   port->read_urb->transfer_buffer,
279 			   port->read_urb->transfer_buffer_length,
280 			   ((serial->type->read_bulk_callback) ?
281 			     serial->type->read_bulk_callback :
282 			     usb_serial_generic_read_bulk_callback), port);
283 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
284 	if (result)
285 		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
286 }
287 
288 void usb_serial_generic_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
289 {
290 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
291 
292 	dbg("%s - port %d", __FUNCTION__, port->number);
293 
294 	if (urb->status) {
295 		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
296 		return;
297 	}
298 
299 	usb_serial_port_softint((void *)port);
300 
301 	schedule_work(&port->work);
302 }
303 
304 void usb_serial_generic_shutdown (struct usb_serial *serial)
305 {
306 	int i;
307 
308 	dbg("%s", __FUNCTION__);
309 
310 	/* stop reads and writes on all ports */
311 	for (i=0; i < serial->num_ports; ++i) {
312 		generic_cleanup(serial->port[i]);
313 	}
314 }
315 
316