aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/symbolserial.c
blob: e53d2aac35c58229fafd907dde5b19a183217bc0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * Symbol USB barcode to serial driver
 *
 * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (C) 2009 Novell Inc.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>

static bool debug;

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x05e0, 0x0600) },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);

/* This structure holds all of the individual device information */
struct symbol_private {
	struct usb_device *udev;
	struct usb_serial *serial;
	struct usb_serial_port *port;
	unsigned char *int_buffer;
	struct urb *int_urb;
	int buffer_size;
	u8 bInterval;
	u8 int_address;
	spinlock_t lock;	/* protects the following flags */
	bool throttled;
	bool actually_throttled;
	bool rts;
};

static void symbol_int_callback(struct urb *urb)
{
	struct symbol_private *priv = urb->context;
	unsigned char *data = urb->transfer_buffer;
	struct usb_serial_port *port = priv->port;
	int status = urb->status;
	struct tty_struct *tty;
	int result;
	int data_length;

	switch (status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
			__func__, status);
		return;
	default:
		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
			__func__, status);
		goto exit;
	}

	usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
			      data);

	if (urb->actual_length > 1) {
		data_length = urb->actual_length - 1;

		/*
		 * Data from the device comes with a 1 byte header:
		 *
		 * <size of data>data...
		 * 	This is real data to be sent to the tty layer
		 * we pretty much just ignore the size and send everything
		 * else to the tty layer.
		 */
		tty = tty_port_tty_get(&port->port);
		if (tty) {
			tty_insert_flip_string(tty, &data[1], data_length);
			tty_flip_buffer_push(tty);
			tty_kref_put(tty);
		}
	} else {
		dev_dbg(&priv->udev->dev,
			"Improper amount of data received from the device, "
			"%d bytes", urb->actual_length);
	}

exit:
	spin_lock(&priv->lock);

	/* Continue trying to always read if we should */
	if (!priv->throttled) {
		usb_fill_int_urb(priv->int_urb, priv->udev,
				 usb_rcvintpipe(priv->udev,
				 		priv->int_address),
				 priv->int_buffer, priv->buffer_size,
				 symbol_int_callback, priv, priv->bInterval);
		result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
		if (result)
			dev_err(&port->dev,
			    "%s - failed resubmitting read urb, error %d\n",
							__func__, result);
	} else
		priv->actually_throttled = true;
	spin_unlock(&priv->lock);
}

static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct symbol_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;
	int result = 0;

	spin_lock_irqsave(&priv->lock, flags);
	priv->throttled = false;
	priv->actually_throttled = false;
	priv->port = port;
	spin_unlock_irqrestore(&priv->lock, flags);

	/* Start reading from the device */
	usb_fill_int_urb(priv->int_urb, priv->udev,
			 usb_rcvintpipe(priv->udev, priv->int_address),
			 priv->int_buffer, priv->buffer_size,
			 symbol_int_callback, priv, priv->bInterval);
	result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
	if (result)
		dev_err(&port->dev,
			"%s - failed resubmitting read urb, error %d\n",
			__func__, result);
	return result;
}

static void symbol_close(struct usb_serial_port *port)
{
	struct symbol_private *priv = usb_get_serial_data(port->serial);

	/* shutdown our urbs */
	usb_kill_urb(priv->int_urb);
}

static void symbol_throttle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct symbol_private *priv = usb_get_serial_data(port->serial);

	spin_lock_irq(&priv->lock);
	priv->throttled = true;
	spin_unlock_irq(&priv->lock);
}

static void symbol_unthrottle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct symbol_private *priv = usb_get_serial_data(port->serial);
	int result;
	bool was_throttled;

	spin_lock_irq(&priv->lock);
	priv->throttled = false;
	was_throttled = priv->actually_throttled;
	priv->actually_throttled = false;
	spin_unlock_irq(&priv->lock);

	if (was_throttled) {
		result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
		if (result)
			dev_err(&port->dev,
				"%s - failed submitting read urb, error %d\n",
							__func__, result);
	}
}

static int symbol_startup(struct usb_serial *serial)
{
	struct symbol_private *priv;
	struct usb_host_interface *intf;
	int i;
	int retval = -ENOMEM;
	bool int_in_found = false;

	/* create our private serial structure */
	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (priv == NULL) {
		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
		return -ENOMEM;
	}
	spin_lock_init(&priv->lock);
	priv->serial = serial;
	priv->port = serial->port[0];
	priv->udev = serial->dev;

	/* find our interrupt endpoint */
	intf = serial->interface->altsetting;
	for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
		struct usb_endpoint_descriptor *endpoint;

		endpoint = &intf->endpoint[i].desc;
		if (!usb_endpoint_is_int_in(endpoint))
			continue;

		priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!priv->int_urb) {
			dev_err(&priv->udev->dev, "out of memory\n");
			goto error;
		}

		priv->buffer_size = usb_endpoint_maxp(endpoint) * 2;
		priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
		if (!priv->int_buffer) {
			dev_err(&priv->udev->dev, "out of memory\n");
			goto error;
		}

		priv->int_address = endpoint->bEndpointAddress;
		priv->bInterval = endpoint->bInterval;

		/* set up our int urb */
		usb_fill_int_urb(priv->int_urb, priv->udev,
				 usb_rcvintpipe(priv->udev,
				 		endpoint->bEndpointAddress),
				 priv->int_buffer, priv->buffer_size,
				 symbol_int_callback, priv, priv->bInterval);

		int_in_found = true;
		break;
		}

	if (!int_in_found) {
		dev_err(&priv->udev->dev,
			"Error - the proper endpoints were not found!\n");
		goto error;
	}

	usb_set_serial_data(serial, priv);
	return 0;

error:
	usb_free_urb(priv->int_urb);
	kfree(priv->int_buffer);
	kfree(priv);
	return retval;
}

static void symbol_disconnect(struct usb_serial *serial)
{
	struct symbol_private *priv = usb_get_serial_data(serial);

	usb_kill_urb(priv->int_urb);
	usb_free_urb(priv->int_urb);
}

static void symbol_release(struct usb_serial *serial)
{
	struct symbol_private *priv = usb_get_serial_data(serial);

	kfree(priv->int_buffer);
	kfree(priv);
}

static struct usb_serial_driver symbol_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"symbol",
	},
	.id_table =		id_table,
	.num_ports =		1,
	.attach =		symbol_startup,
	.open =			symbol_open,
	.close =		symbol_close,
	.disconnect =		symbol_disconnect,
	.release =		symbol_release,
	.throttle = 		symbol_throttle,
	.unthrottle =		symbol_unthrottle,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&symbol_device, NULL
};

module_usb_serial_driver(serial_drivers, id_table);

MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");