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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Opticon USB barcode to serial driver
4 *
5 * Copyright (C) 2011 - 2012 Johan Hovold <[email protected]>
6 * Copyright (C) 2011 Martin Jansen <[email protected]>
7 * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <[email protected]>
8 * Copyright (C) 2008 - 2009 Novell Inc.
9 */
10
11#include <linux/kernel.h>
12#include <linux/tty.h>
13#include <linux/slab.h>
14#include <linux/tty_flip.h>
15#include <linux/serial.h>
16#include <linux/module.h>
17#include <linux/usb.h>
18#include <linux/usb/serial.h>
19
20#define CONTROL_RTS 0x02
21#define RESEND_CTS_STATE 0x03
22
23/* max number of write urbs in flight */
24#define URB_UPPER_LIMIT 8
25
26/* This driver works for the Opticon 1D barcode reader
27 * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */
28#define DRIVER_DESC "Opticon USB barcode to serial driver (1D)"
29
30static const struct usb_device_id id_table[] = {
31 { USB_DEVICE(0x065a, 0x0009) },
32 { },
33};
34MODULE_DEVICE_TABLE(usb, id_table);
35
36/* This structure holds all of the individual device information */
37struct opticon_private {
38 spinlock_t lock; /* protects the following flags */
39 bool rts;
40 bool cts;
41 int outstanding_urbs;
42 int outstanding_bytes;
43
44 struct usb_anchor anchor;
45};
46
47
48static void opticon_process_data_packet(struct usb_serial_port *port,
49 const unsigned char *buf, size_t len)
50{
51 tty_insert_flip_string(&port->port, buf, len);
52 tty_flip_buffer_push(&port->port);
53}
54
55static void opticon_process_status_packet(struct usb_serial_port *port,
56 const unsigned char *buf, size_t len)
57{
58 struct opticon_private *priv = usb_get_serial_port_data(port);
59 unsigned long flags;
60
61 spin_lock_irqsave(&priv->lock, flags);
62 if (buf[0] == 0x00)
63 priv->cts = false;
64 else
65 priv->cts = true;
66 spin_unlock_irqrestore(&priv->lock, flags);
67}
68
69static void opticon_process_read_urb(struct urb *urb)
70{
71 struct usb_serial_port *port = urb->context;
72 const unsigned char *hdr = urb->transfer_buffer;
73 const unsigned char *data = hdr + 2;
74 size_t data_len = urb->actual_length - 2;
75
76 if (urb->actual_length <= 2) {
77 dev_dbg(&port->dev, "malformed packet received: %d bytes\n",
78 urb->actual_length);
79 return;
80 }
81 /*
82 * Data from the device comes with a 2 byte header:
83 *
84 * <0x00><0x00>data...
85 * This is real data to be sent to the tty layer
86 * <0x00><0x01>level
87 * This is a CTS level change, the third byte is the CTS
88 * value (0 for low, 1 for high).
89 */
90 if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) {
91 opticon_process_data_packet(port, data, data_len);
92 } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) {
93 opticon_process_status_packet(port, data, data_len);
94 } else {
95 dev_dbg(&port->dev, "unknown packet received: %02x %02x\n",
96 hdr[0], hdr[1]);
97 }
98}
99
100static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
101 u8 val)
102{
103 struct usb_serial *serial = port->serial;
104 int retval;
105 u8 *buffer;
106
107 buffer = kzalloc(1, GFP_KERNEL);
108 if (!buffer)
109 return -ENOMEM;
110
111 buffer[0] = val;
112 /* Send the message to the vendor control endpoint
113 * of the connected device */
114 retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
115 requesttype,
116 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
117 0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT);
118 kfree(buffer);
119
120 if (retval < 0)
121 return retval;
122
123 return 0;
124}
125
126static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
127{
128 struct opticon_private *priv = usb_get_serial_port_data(port);
129 unsigned long flags;
130 int res;
131
132 spin_lock_irqsave(&priv->lock, flags);
133 priv->rts = false;
134 spin_unlock_irqrestore(&priv->lock, flags);
135
136 /* Clear RTS line */
137 send_control_msg(port, CONTROL_RTS, 0);
138
139 /* clear the halt status of the endpoint */
140 usb_clear_halt(port->serial->dev, port->read_urb->pipe);
141
142 res = usb_serial_generic_open(tty, port);
143 if (res)
144 return res;
145
146 /* Request CTS line state, sometimes during opening the current
147 * CTS state can be missed. */
148 send_control_msg(port, RESEND_CTS_STATE, 1);
149
150 return res;
151}
152
153static void opticon_close(struct usb_serial_port *port)
154{
155 struct opticon_private *priv = usb_get_serial_port_data(port);
156
157 usb_kill_anchored_urbs(&priv->anchor);
158
159 usb_serial_generic_close(port);
160}
161
162static void opticon_write_control_callback(struct urb *urb)
163{
164 struct usb_serial_port *port = urb->context;
165 struct opticon_private *priv = usb_get_serial_port_data(port);
166 int status = urb->status;
167 unsigned long flags;
168
169 /* free up the transfer buffer, as usb_free_urb() does not do this */
170 kfree(urb->transfer_buffer);
171
172 /* setup packet may be set if we're using it for writing */
173 kfree(urb->setup_packet);
174
175 if (status)
176 dev_dbg(&port->dev,
177 "%s - non-zero urb status received: %d\n",
178 __func__, status);
179
180 spin_lock_irqsave(&priv->lock, flags);
181 --priv->outstanding_urbs;
182 priv->outstanding_bytes -= urb->transfer_buffer_length;
183 spin_unlock_irqrestore(&priv->lock, flags);
184
185 usb_serial_port_softint(port);
186}
187
188static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
189 const unsigned char *buf, int count)
190{
191 struct opticon_private *priv = usb_get_serial_port_data(port);
192 struct usb_serial *serial = port->serial;
193 struct urb *urb;
194 unsigned char *buffer;
195 unsigned long flags;
196 struct usb_ctrlrequest *dr;
197 int ret = -ENOMEM;
198
199 spin_lock_irqsave(&priv->lock, flags);
200 if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
201 spin_unlock_irqrestore(&priv->lock, flags);
202 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
203 return 0;
204 }
205 priv->outstanding_urbs++;
206 priv->outstanding_bytes += count;
207 spin_unlock_irqrestore(&priv->lock, flags);
208
209 buffer = kmemdup(buf, count, GFP_ATOMIC);
210 if (!buffer)
211 goto error_no_buffer;
212
213 urb = usb_alloc_urb(0, GFP_ATOMIC);
214 if (!urb)
215 goto error_no_urb;
216
217 usb_serial_debug_data(&port->dev, __func__, count, buffer);
218
219 /* The connected devices do not have a bulk write endpoint,
220 * to transmit data to de barcode device the control endpoint is used */
221 dr = kmalloc_obj(struct usb_ctrlrequest, GFP_ATOMIC);
222 if (!dr)
223 goto error_no_dr;
224
225 dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
226 dr->bRequest = 0x01;
227 dr->wValue = 0;
228 dr->wIndex = 0;
229 dr->wLength = cpu_to_le16(count);
230
231 usb_fill_control_urb(urb, serial->dev,
232 usb_sndctrlpipe(serial->dev, 0),
233 (unsigned char *)dr, buffer, count,
234 opticon_write_control_callback, port);
235
236 usb_anchor_urb(urb, &priv->anchor);
237
238 /* send it down the pipe */
239 ret = usb_submit_urb(urb, GFP_ATOMIC);
240 if (ret) {
241 dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
242 usb_unanchor_urb(urb);
243 goto error;
244 }
245
246 /* we are done with this urb, so let the host driver
247 * really free it when it is finished with it */
248 usb_free_urb(urb);
249
250 return count;
251error:
252 kfree(dr);
253error_no_dr:
254 usb_free_urb(urb);
255error_no_urb:
256 kfree(buffer);
257error_no_buffer:
258 spin_lock_irqsave(&priv->lock, flags);
259 --priv->outstanding_urbs;
260 priv->outstanding_bytes -= count;
261 spin_unlock_irqrestore(&priv->lock, flags);
262
263 return ret;
264}
265
266static unsigned int opticon_write_room(struct tty_struct *tty)
267{
268 struct usb_serial_port *port = tty->driver_data;
269 struct opticon_private *priv = usb_get_serial_port_data(port);
270 unsigned long flags;
271
272 /*
273 * We really can take almost anything the user throws at us
274 * but let's pick a nice big number to tell the tty
275 * layer that we have lots of free space, unless we don't.
276 */
277 spin_lock_irqsave(&priv->lock, flags);
278 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
279 spin_unlock_irqrestore(&priv->lock, flags);
280 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
281 return 0;
282 }
283 spin_unlock_irqrestore(&priv->lock, flags);
284
285 return 2048;
286}
287
288static unsigned int opticon_chars_in_buffer(struct tty_struct *tty)
289{
290 struct usb_serial_port *port = tty->driver_data;
291 struct opticon_private *priv = usb_get_serial_port_data(port);
292 unsigned long flags;
293 unsigned int count;
294
295 spin_lock_irqsave(&priv->lock, flags);
296 count = priv->outstanding_bytes;
297 spin_unlock_irqrestore(&priv->lock, flags);
298
299 return count;
300}
301
302static int opticon_tiocmget(struct tty_struct *tty)
303{
304 struct usb_serial_port *port = tty->driver_data;
305 struct opticon_private *priv = usb_get_serial_port_data(port);
306 unsigned long flags;
307 int result = 0;
308
309 spin_lock_irqsave(&priv->lock, flags);
310 if (priv->rts)
311 result |= TIOCM_RTS;
312 if (priv->cts)
313 result |= TIOCM_CTS;
314 spin_unlock_irqrestore(&priv->lock, flags);
315
316 dev_dbg(&port->dev, "%s - %x\n", __func__, result);
317 return result;
318}
319
320static int opticon_tiocmset(struct tty_struct *tty,
321 unsigned int set, unsigned int clear)
322{
323 struct usb_serial_port *port = tty->driver_data;
324 struct opticon_private *priv = usb_get_serial_port_data(port);
325 unsigned long flags;
326 bool rts;
327 bool changed = false;
328 int ret;
329
330 /* We only support RTS so we only handle that */
331 spin_lock_irqsave(&priv->lock, flags);
332
333 rts = priv->rts;
334 if (set & TIOCM_RTS)
335 priv->rts = true;
336 if (clear & TIOCM_RTS)
337 priv->rts = false;
338 changed = rts ^ priv->rts;
339 spin_unlock_irqrestore(&priv->lock, flags);
340
341 if (!changed)
342 return 0;
343
344 ret = send_control_msg(port, CONTROL_RTS, !rts);
345 if (ret)
346 return usb_translate_errors(ret);
347
348 return 0;
349}
350
351static int opticon_port_probe(struct usb_serial_port *port)
352{
353 struct opticon_private *priv;
354
355 priv = kzalloc_obj(*priv);
356 if (!priv)
357 return -ENOMEM;
358
359 spin_lock_init(&priv->lock);
360 init_usb_anchor(&priv->anchor);
361
362 usb_set_serial_port_data(port, priv);
363
364 return 0;
365}
366
367static void opticon_port_remove(struct usb_serial_port *port)
368{
369 struct opticon_private *priv = usb_get_serial_port_data(port);
370
371 kfree(priv);
372}
373
374static struct usb_serial_driver opticon_device = {
375 .driver = {
376 .name = "opticon",
377 },
378 .id_table = id_table,
379 .num_ports = 1,
380 .num_bulk_in = 1,
381 .bulk_in_size = 256,
382 .port_probe = opticon_port_probe,
383 .port_remove = opticon_port_remove,
384 .open = opticon_open,
385 .close = opticon_close,
386 .write = opticon_write,
387 .write_room = opticon_write_room,
388 .chars_in_buffer = opticon_chars_in_buffer,
389 .throttle = usb_serial_generic_throttle,
390 .unthrottle = usb_serial_generic_unthrottle,
391 .tiocmget = opticon_tiocmget,
392 .tiocmset = opticon_tiocmset,
393 .process_read_urb = opticon_process_read_urb,
394};
395
396static struct usb_serial_driver * const serial_drivers[] = {
397 &opticon_device, NULL
398};
399
400module_usb_serial_driver(serial_drivers, id_table);
401
402MODULE_DESCRIPTION(DRIVER_DESC);
403MODULE_LICENSE("GPL v2");