1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver
4 *
5 *  Copyright (C) 2001  REINER SCT
6 *  Author: Matthias Bruestle
7 *
8 *  Contact: support@reiner-sct.com (see MAINTAINERS)
9 *
10 *  This program is largely derived from work by the linux-usb group
11 *  and associated source files.  Please see the usb/serial files for
12 *  individual credits and copyrights.
13 *
14 *  Thanks to Greg Kroah-Hartman (greg@kroah.com) for his help and
15 *  patience.
16 *
17 *  In case of problems, please write to the contact e-mail address
18 *  mentioned above.
19 *
20 *  Please note that later models of the cyberjack reader family are
21 *  supported by a libusb-based userspace device driver.
22 *
23 *  Homepage: http://www.reiner-sct.de/support/treiber_cyberjack.php#linux
24 */
25
26
27#include <linux/kernel.h>
28#include <linux/errno.h>
29#include <linux/slab.h>
30#include <linux/tty.h>
31#include <linux/tty_driver.h>
32#include <linux/tty_flip.h>
33#include <linux/module.h>
34#include <linux/spinlock.h>
35#include <linux/uaccess.h>
36#include <linux/usb.h>
37#include <linux/usb/serial.h>
38
39#define CYBERJACK_LOCAL_BUF_SIZE 32
40
41#define DRIVER_AUTHOR "Matthias Bruestle"
42#define DRIVER_DESC "REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver"
43
44
45#define CYBERJACK_VENDOR_ID	0x0C4B
46#define CYBERJACK_PRODUCT_ID	0x0100
47
48/* Function prototypes */
49static int cyberjack_port_probe(struct usb_serial_port *port);
50static void cyberjack_port_remove(struct usb_serial_port *port);
51static int  cyberjack_open(struct tty_struct *tty,
52	struct usb_serial_port *port);
53static void cyberjack_close(struct usb_serial_port *port);
54static int cyberjack_write(struct tty_struct *tty,
55	struct usb_serial_port *port, const unsigned char *buf, int count);
56static unsigned int cyberjack_write_room(struct tty_struct *tty);
57static void cyberjack_read_int_callback(struct urb *urb);
58static void cyberjack_read_bulk_callback(struct urb *urb);
59static void cyberjack_write_bulk_callback(struct urb *urb);
60
61static const struct usb_device_id id_table[] = {
62	{ USB_DEVICE(CYBERJACK_VENDOR_ID, CYBERJACK_PRODUCT_ID) },
63	{ }			/* Terminating entry */
64};
65
66MODULE_DEVICE_TABLE(usb, id_table);
67
68static struct usb_serial_driver cyberjack_device = {
69	.driver = {
70		.owner =	THIS_MODULE,
71		.name =		"cyberjack",
72	},
73	.description =		"Reiner SCT Cyberjack USB card reader",
74	.id_table =		id_table,
75	.num_ports =		1,
76	.num_bulk_out =		1,
77	.port_probe =		cyberjack_port_probe,
78	.port_remove =		cyberjack_port_remove,
79	.open =			cyberjack_open,
80	.close =		cyberjack_close,
81	.write =		cyberjack_write,
82	.write_room =		cyberjack_write_room,
83	.read_int_callback =	cyberjack_read_int_callback,
84	.read_bulk_callback =	cyberjack_read_bulk_callback,
85	.write_bulk_callback =	cyberjack_write_bulk_callback,
86};
87
88static struct usb_serial_driver * const serial_drivers[] = {
89	&cyberjack_device, NULL
90};
91
92struct cyberjack_private {
93	spinlock_t	lock;		/* Lock for SMP */
94	short		rdtodo;		/* Bytes still to read */
95	unsigned char	wrbuf[5*64];	/* Buffer for collecting data to write */
96	short		wrfilled;	/* Overall data size we already got */
97	short		wrsent;		/* Data already sent */
98};
99
100static int cyberjack_port_probe(struct usb_serial_port *port)
101{
102	struct cyberjack_private *priv;
103	int result;
104
105	priv = kmalloc(sizeof(struct cyberjack_private), GFP_KERNEL);
106	if (!priv)
107		return -ENOMEM;
108
109	spin_lock_init(&priv->lock);
110	priv->rdtodo = 0;
111	priv->wrfilled = 0;
112	priv->wrsent = 0;
113
114	usb_set_serial_port_data(port, priv);
115
116	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
117	if (result)
118		dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
119
120	return 0;
121}
122
123static void cyberjack_port_remove(struct usb_serial_port *port)
124{
125	struct cyberjack_private *priv;
126
127	usb_kill_urb(port->interrupt_in_urb);
128
129	priv = usb_get_serial_port_data(port);
130	kfree(priv);
131}
132
133static int  cyberjack_open(struct tty_struct *tty,
134					struct usb_serial_port *port)
135{
136	struct cyberjack_private *priv;
137	unsigned long flags;
138
139	dev_dbg(&port->dev, "%s - usb_clear_halt\n", __func__);
140	usb_clear_halt(port->serial->dev, port->write_urb->pipe);
141
142	priv = usb_get_serial_port_data(port);
143	spin_lock_irqsave(&priv->lock, flags);
144	priv->rdtodo = 0;
145	priv->wrfilled = 0;
146	priv->wrsent = 0;
147	spin_unlock_irqrestore(&priv->lock, flags);
148
149	return 0;
150}
151
152static void cyberjack_close(struct usb_serial_port *port)
153{
154	usb_kill_urb(port->write_urb);
155	usb_kill_urb(port->read_urb);
156}
157
158static int cyberjack_write(struct tty_struct *tty,
159	struct usb_serial_port *port, const unsigned char *buf, int count)
160{
161	struct device *dev = &port->dev;
162	struct cyberjack_private *priv = usb_get_serial_port_data(port);
163	unsigned long flags;
164	int result;
165	int wrexpected;
166
167	if (count == 0) {
168		dev_dbg(dev, "%s - write request of 0 bytes\n", __func__);
169		return 0;
170	}
171
172	if (!test_and_clear_bit(0, &port->write_urbs_free)) {
173		dev_dbg(dev, "%s - already writing\n", __func__);
174		return 0;
175	}
176
177	spin_lock_irqsave(&priv->lock, flags);
178
179	if (count+priv->wrfilled > sizeof(priv->wrbuf)) {
180		/* To much data for buffer. Reset buffer. */
181		priv->wrfilled = 0;
182		spin_unlock_irqrestore(&priv->lock, flags);
183		set_bit(0, &port->write_urbs_free);
184		return 0;
185	}
186
187	/* Copy data */
188	memcpy(priv->wrbuf + priv->wrfilled, buf, count);
189
190	usb_serial_debug_data(dev, __func__, count, priv->wrbuf + priv->wrfilled);
191	priv->wrfilled += count;
192
193	if (priv->wrfilled >= 3) {
194		wrexpected = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
195		dev_dbg(dev, "%s - expected data: %d\n", __func__, wrexpected);
196	} else
197		wrexpected = sizeof(priv->wrbuf);
198
199	if (priv->wrfilled >= wrexpected) {
200		/* We have enough data to begin transmission */
201		int length;
202
203		dev_dbg(dev, "%s - transmitting data (frame 1)\n", __func__);
204		length = (wrexpected > port->bulk_out_size) ?
205					port->bulk_out_size : wrexpected;
206
207		memcpy(port->write_urb->transfer_buffer, priv->wrbuf, length);
208		priv->wrsent = length;
209
210		/* set up our urb */
211		port->write_urb->transfer_buffer_length = length;
212
213		/* send the data out the bulk port */
214		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
215		if (result) {
216			dev_err(&port->dev,
217				"%s - failed submitting write urb, error %d\n",
218				__func__, result);
219			/* Throw away data. No better idea what to do with it. */
220			priv->wrfilled = 0;
221			priv->wrsent = 0;
222			spin_unlock_irqrestore(&priv->lock, flags);
223			set_bit(0, &port->write_urbs_free);
224			return 0;
225		}
226
227		dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent);
228		dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled);
229
230		if (priv->wrsent >= priv->wrfilled) {
231			dev_dbg(dev, "%s - buffer cleaned\n", __func__);
232			memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
233			priv->wrfilled = 0;
234			priv->wrsent = 0;
235		}
236	}
237
238	spin_unlock_irqrestore(&priv->lock, flags);
239
240	return count;
241}
242
243static unsigned int cyberjack_write_room(struct tty_struct *tty)
244{
245	/* FIXME: .... */
246	return CYBERJACK_LOCAL_BUF_SIZE;
247}
248
249static void cyberjack_read_int_callback(struct urb *urb)
250{
251	struct usb_serial_port *port = urb->context;
252	struct cyberjack_private *priv = usb_get_serial_port_data(port);
253	struct device *dev = &port->dev;
254	unsigned char *data = urb->transfer_buffer;
255	int status = urb->status;
256	unsigned long flags;
257	int result;
258
259	/* the urb might have been killed. */
260	if (status)
261		return;
262
263	usb_serial_debug_data(dev, __func__, urb->actual_length, data);
264
265	/* React only to interrupts signaling a bulk_in transfer */
266	if (urb->actual_length == 4 && data[0] == 0x01) {
267		short old_rdtodo;
268
269		/* This is a announcement of coming bulk_ins. */
270		unsigned short size = ((unsigned short)data[3]<<8)+data[2]+3;
271
272		spin_lock_irqsave(&priv->lock, flags);
273
274		old_rdtodo = priv->rdtodo;
275
276		if (old_rdtodo > SHRT_MAX - size) {
277			dev_dbg(dev, "Too many bulk_in urbs to do.\n");
278			spin_unlock_irqrestore(&priv->lock, flags);
279			goto resubmit;
280		}
281
282		/* "+=" is probably more fault tolerant than "=" */
283		priv->rdtodo += size;
284
285		dev_dbg(dev, "%s - rdtodo: %d\n", __func__, priv->rdtodo);
286
287		spin_unlock_irqrestore(&priv->lock, flags);
288
289		if (!old_rdtodo) {
290			result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
291			if (result)
292				dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
293					__func__, result);
294			dev_dbg(dev, "%s - usb_submit_urb(read urb)\n", __func__);
295		}
296	}
297
298resubmit:
299	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
300	if (result)
301		dev_err(&port->dev, "usb_submit_urb(read int) failed\n");
302	dev_dbg(dev, "%s - usb_submit_urb(int urb)\n", __func__);
303}
304
305static void cyberjack_read_bulk_callback(struct urb *urb)
306{
307	struct usb_serial_port *port = urb->context;
308	struct cyberjack_private *priv = usb_get_serial_port_data(port);
309	struct device *dev = &port->dev;
310	unsigned char *data = urb->transfer_buffer;
311	unsigned long flags;
312	short todo;
313	int result;
314	int status = urb->status;
315
316	usb_serial_debug_data(dev, __func__, urb->actual_length, data);
317	if (status) {
318		dev_dbg(dev, "%s - nonzero read bulk status received: %d\n",
319			__func__, status);
320		return;
321	}
322
323	if (urb->actual_length) {
324		tty_insert_flip_string(&port->port, data, urb->actual_length);
325		tty_flip_buffer_push(&port->port);
326	}
327
328	spin_lock_irqsave(&priv->lock, flags);
329
330	/* Reduce urbs to do by one. */
331	priv->rdtodo -= urb->actual_length;
332	/* Just to be sure */
333	if (priv->rdtodo < 0)
334		priv->rdtodo = 0;
335	todo = priv->rdtodo;
336
337	spin_unlock_irqrestore(&priv->lock, flags);
338
339	dev_dbg(dev, "%s - rdtodo: %d\n", __func__, todo);
340
341	/* Continue to read if we have still urbs to do. */
342	if (todo /* || (urb->actual_length==port->bulk_in_endpointAddress)*/) {
343		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
344		if (result)
345			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
346				__func__, result);
347		dev_dbg(dev, "%s - usb_submit_urb(read urb)\n", __func__);
348	}
349}
350
351static void cyberjack_write_bulk_callback(struct urb *urb)
352{
353	struct usb_serial_port *port = urb->context;
354	struct cyberjack_private *priv = usb_get_serial_port_data(port);
355	struct device *dev = &port->dev;
356	int status = urb->status;
357	unsigned long flags;
358	bool resubmitted = false;
359
360	if (status) {
361		dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
362			__func__, status);
363		set_bit(0, &port->write_urbs_free);
364		return;
365	}
366
367	spin_lock_irqsave(&priv->lock, flags);
368
369	/* only do something if we have more data to send */
370	if (priv->wrfilled) {
371		int length, blksize, result;
372
373		dev_dbg(dev, "%s - transmitting data (frame n)\n", __func__);
374
375		length = ((priv->wrfilled - priv->wrsent) > port->bulk_out_size) ?
376			port->bulk_out_size : (priv->wrfilled - priv->wrsent);
377
378		memcpy(port->write_urb->transfer_buffer,
379					priv->wrbuf + priv->wrsent, length);
380		priv->wrsent += length;
381
382		/* set up our urb */
383		port->write_urb->transfer_buffer_length = length;
384
385		/* send the data out the bulk port */
386		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
387		if (result) {
388			dev_err(dev, "%s - failed submitting write urb, error %d\n",
389				__func__, result);
390			/* Throw away data. No better idea what to do with it. */
391			priv->wrfilled = 0;
392			priv->wrsent = 0;
393			goto exit;
394		}
395
396		resubmitted = true;
397
398		dev_dbg(dev, "%s - priv->wrsent=%d\n", __func__, priv->wrsent);
399		dev_dbg(dev, "%s - priv->wrfilled=%d\n", __func__, priv->wrfilled);
400
401		blksize = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
402
403		if (priv->wrsent >= priv->wrfilled ||
404					priv->wrsent >= blksize) {
405			dev_dbg(dev, "%s - buffer cleaned\n", __func__);
406			memset(priv->wrbuf, 0, sizeof(priv->wrbuf));
407			priv->wrfilled = 0;
408			priv->wrsent = 0;
409		}
410	}
411
412exit:
413	spin_unlock_irqrestore(&priv->lock, flags);
414	if (!resubmitted)
415		set_bit(0, &port->write_urbs_free);
416	usb_serial_port_softint(port);
417}
418
419module_usb_serial_driver(serial_drivers, id_table);
420
421MODULE_AUTHOR(DRIVER_AUTHOR);
422MODULE_DESCRIPTION(DRIVER_DESC);
423MODULE_LICENSE("GPL");
424