1 /*
2  * dvb_ca.c: generic DVB functions for EN50221 CAM interfaces
3  *
4  * Copyright (C) 2004 Andrew de Quincey
5  *
6  * Parts of this file were based on sources as follows:
7  *
8  * Copyright (C) 2003 Ralph Metzler <rjkm@metzlerbros.de>
9  *
10  * based on code:
11  *
12  * Copyright (C) 1999-2002 Ralph  Metzler
13  *                       & Marcus Metzler for convergence integrated media GmbH
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * as published by the Free Software Foundation; either version 2
18  * of the License, or (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  * To obtain the license, point your browser to
25  * http://www.gnu.org/copyleft/gpl.html
26  */
27 
28 #define pr_fmt(fmt) "dvb_ca_en50221: " fmt
29 
30 #include <linux/errno.h>
31 #include <linux/slab.h>
32 #include <linux/list.h>
33 #include <linux/module.h>
34 #include <linux/vmalloc.h>
35 #include <linux/delay.h>
36 #include <linux/spinlock.h>
37 #include <linux/sched/signal.h>
38 #include <linux/kthread.h>
39 
40 #include "dvb_ca_en50221.h"
41 #include "dvb_ringbuffer.h"
42 
43 static int dvb_ca_en50221_debug;
44 
45 module_param_named(cam_debug, dvb_ca_en50221_debug, int, 0644);
46 MODULE_PARM_DESC(cam_debug, "enable verbose debug messages");
47 
48 #define dprintk(fmt, arg...) do {					\
49 	if (dvb_ca_en50221_debug)					\
50 		printk(KERN_DEBUG pr_fmt("%s: " fmt), __func__, ##arg);\
51 } while (0)
52 
53 #define INIT_TIMEOUT_SECS 10
54 
55 #define HOST_LINK_BUF_SIZE 0x200
56 
57 #define RX_BUFFER_SIZE 65535
58 
59 #define MAX_RX_PACKETS_PER_ITERATION 10
60 
61 #define CTRLIF_DATA      0
62 #define CTRLIF_COMMAND   1
63 #define CTRLIF_STATUS    1
64 #define CTRLIF_SIZE_LOW  2
65 #define CTRLIF_SIZE_HIGH 3
66 
67 #define CMDREG_HC        1	/* Host control */
68 #define CMDREG_SW        2	/* Size write */
69 #define CMDREG_SR        4	/* Size read */
70 #define CMDREG_RS        8	/* Reset interface */
71 #define CMDREG_FRIE   0x40	/* Enable FR interrupt */
72 #define CMDREG_DAIE   0x80	/* Enable DA interrupt */
73 #define IRQEN (CMDREG_DAIE)
74 
75 #define STATUSREG_RE     1	/* read error */
76 #define STATUSREG_WE     2	/* write error */
77 #define STATUSREG_FR  0x40	/* module free */
78 #define STATUSREG_DA  0x80	/* data available */
79 
80 #define DVB_CA_SLOTSTATE_NONE           0
81 #define DVB_CA_SLOTSTATE_UNINITIALISED  1
82 #define DVB_CA_SLOTSTATE_RUNNING        2
83 #define DVB_CA_SLOTSTATE_INVALID        3
84 #define DVB_CA_SLOTSTATE_WAITREADY      4
85 #define DVB_CA_SLOTSTATE_VALIDATE       5
86 #define DVB_CA_SLOTSTATE_WAITFR         6
87 #define DVB_CA_SLOTSTATE_LINKINIT       7
88 
89 /* Information on a CA slot */
90 struct dvb_ca_slot {
91 	/* current state of the CAM */
92 	int slot_state;
93 
94 	/* mutex used for serializing access to one CI slot */
95 	struct mutex slot_lock;
96 
97 	/* Number of CAMCHANGES that have occurred since last processing */
98 	atomic_t camchange_count;
99 
100 	/* Type of last CAMCHANGE */
101 	int camchange_type;
102 
103 	/* base address of CAM config */
104 	u32 config_base;
105 
106 	/* value to write into Config Control register */
107 	u8 config_option;
108 
109 	/* if 1, the CAM supports DA IRQs */
110 	u8 da_irq_supported:1;
111 
112 	/* size of the buffer to use when talking to the CAM */
113 	int link_buf_size;
114 
115 	/* buffer for incoming packets */
116 	struct dvb_ringbuffer rx_buffer;
117 
118 	/* timer used during various states of the slot */
119 	unsigned long timeout;
120 };
121 
122 /* Private CA-interface information */
123 struct dvb_ca_private {
124 	struct kref refcount;
125 
126 	/* pointer back to the public data structure */
127 	struct dvb_ca_en50221 *pub;
128 
129 	/* the DVB device */
130 	struct dvb_device *dvbdev;
131 
132 	/* Flags describing the interface (DVB_CA_FLAG_*) */
133 	u32 flags;
134 
135 	/* number of slots supported by this CA interface */
136 	unsigned int slot_count;
137 
138 	/* information on each slot */
139 	struct dvb_ca_slot *slot_info;
140 
141 	/* wait queues for read() and write() operations */
142 	wait_queue_head_t wait_queue;
143 
144 	/* PID of the monitoring thread */
145 	struct task_struct *thread;
146 
147 	/* Flag indicating if the CA device is open */
148 	unsigned int open:1;
149 
150 	/* Flag indicating the thread should wake up now */
151 	unsigned int wakeup:1;
152 
153 	/* Delay the main thread should use */
154 	unsigned long delay;
155 
156 	/*
157 	 * Slot to start looking for data to read from in the next user-space
158 	 * read operation
159 	 */
160 	int next_read_slot;
161 
162 	/* mutex serializing ioctls */
163 	struct mutex ioctl_mutex;
164 };
165 
166 static void dvb_ca_private_free(struct dvb_ca_private *ca)
167 {
168 	unsigned int i;
169 
170 	dvb_free_device(ca->dvbdev);
171 	for (i = 0; i < ca->slot_count; i++)
172 		vfree(ca->slot_info[i].rx_buffer.data);
173 
174 	kfree(ca->slot_info);
175 	kfree(ca);
176 }
177 
178 static void dvb_ca_private_release(struct kref *ref)
179 {
180 	struct dvb_ca_private *ca;
181 
182 	ca = container_of(ref, struct dvb_ca_private, refcount);
183 	dvb_ca_private_free(ca);
184 }
185 
186 static void dvb_ca_private_get(struct dvb_ca_private *ca)
187 {
188 	kref_get(&ca->refcount);
189 }
190 
191 static void dvb_ca_private_put(struct dvb_ca_private *ca)
192 {
193 	kref_put(&ca->refcount, dvb_ca_private_release);
194 }
195 
196 static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca);
197 static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
198 				    u8 *ebuf, int ecount);
199 static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
200 				     u8 *ebuf, int ecount);
201 
202 /**
203  * Safely find needle in haystack.
204  *
205  * @haystack: Buffer to look in.
206  * @hlen: Number of bytes in haystack.
207  * @needle: Buffer to find.
208  * @nlen: Number of bytes in needle.
209  * @return Pointer into haystack needle was found at, or NULL if not found.
210  */
211 static char *findstr(char *haystack, int hlen, char *needle, int nlen)
212 {
213 	int i;
214 
215 	if (hlen < nlen)
216 		return NULL;
217 
218 	for (i = 0; i <= hlen - nlen; i++) {
219 		if (!strncmp(haystack + i, needle, nlen))
220 			return haystack + i;
221 	}
222 
223 	return NULL;
224 }
225 
226 /* ************************************************************************** */
227 /* EN50221 physical interface functions */
228 
229 /**
230  * dvb_ca_en50221_check_camstatus - Check CAM status.
231  */
232 static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private *ca, int slot)
233 {
234 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
235 	int slot_status;
236 	int cam_present_now;
237 	int cam_changed;
238 
239 	/* IRQ mode */
240 	if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
241 		return (atomic_read(&sl->camchange_count) != 0);
242 
243 	/* poll mode */
244 	slot_status = ca->pub->poll_slot_status(ca->pub, slot, ca->open);
245 
246 	cam_present_now = (slot_status & DVB_CA_EN50221_POLL_CAM_PRESENT) ? 1 : 0;
247 	cam_changed = (slot_status & DVB_CA_EN50221_POLL_CAM_CHANGED) ? 1 : 0;
248 	if (!cam_changed) {
249 		int cam_present_old = (sl->slot_state != DVB_CA_SLOTSTATE_NONE);
250 
251 		cam_changed = (cam_present_now != cam_present_old);
252 	}
253 
254 	if (cam_changed) {
255 		if (!cam_present_now)
256 			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
257 		else
258 			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
259 		atomic_set(&sl->camchange_count, 1);
260 	} else {
261 		if ((sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
262 		    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
263 			/* move to validate state if reset is completed */
264 			sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
265 		}
266 	}
267 
268 	return cam_changed;
269 }
270 
271 /**
272  * dvb_ca_en50221_wait_if_status - Wait for flags to become set on the STATUS
273  *	 register on a CAM interface, checking for errors and timeout.
274  *
275  * @ca: CA instance.
276  * @slot: Slot on interface.
277  * @waitfor: Flags to wait for.
278  * @timeout_ms: Timeout in milliseconds.
279  *
280  * @return 0 on success, nonzero on error.
281  */
282 static int dvb_ca_en50221_wait_if_status(struct dvb_ca_private *ca, int slot,
283 					 u8 waitfor, int timeout_hz)
284 {
285 	unsigned long timeout;
286 	unsigned long start;
287 
288 	dprintk("%s\n", __func__);
289 
290 	/* loop until timeout elapsed */
291 	start = jiffies;
292 	timeout = jiffies + timeout_hz;
293 	while (1) {
294 		int res;
295 
296 		/* read the status and check for error */
297 		res = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
298 		if (res < 0)
299 			return -EIO;
300 
301 		/* if we got the flags, it was successful! */
302 		if (res & waitfor) {
303 			dprintk("%s succeeded timeout:%lu\n",
304 				__func__, jiffies - start);
305 			return 0;
306 		}
307 
308 		/* check for timeout */
309 		if (time_after(jiffies, timeout))
310 			break;
311 
312 		/* wait for a bit */
313 		usleep_range(1000, 1100);
314 	}
315 
316 	dprintk("%s failed timeout:%lu\n", __func__, jiffies - start);
317 
318 	/* if we get here, we've timed out */
319 	return -ETIMEDOUT;
320 }
321 
322 /**
323  * dvb_ca_en50221_link_init - Initialise the link layer connection to a CAM.
324  *
325  * @ca: CA instance.
326  * @slot: Slot id.
327  *
328  * @return 0 on success, nonzero on failure.
329  */
330 static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot)
331 {
332 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
333 	int ret;
334 	int buf_size;
335 	u8 buf[2];
336 
337 	dprintk("%s\n", __func__);
338 
339 	/* we'll be determining these during this function */
340 	sl->da_irq_supported = 0;
341 
342 	/*
343 	 * set the host link buffer size temporarily. it will be overwritten
344 	 * with the real negotiated size later.
345 	 */
346 	sl->link_buf_size = 2;
347 
348 	/* read the buffer size from the CAM */
349 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
350 					 IRQEN | CMDREG_SR);
351 	if (ret)
352 		return ret;
353 	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ);
354 	if (ret)
355 		return ret;
356 	ret = dvb_ca_en50221_read_data(ca, slot, buf, 2);
357 	if (ret != 2)
358 		return -EIO;
359 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
360 	if (ret)
361 		return ret;
362 
363 	/*
364 	 * store it, and choose the minimum of our buffer and the CAM's buffer
365 	 * size
366 	 */
367 	buf_size = (buf[0] << 8) | buf[1];
368 	if (buf_size > HOST_LINK_BUF_SIZE)
369 		buf_size = HOST_LINK_BUF_SIZE;
370 	sl->link_buf_size = buf_size;
371 	buf[0] = buf_size >> 8;
372 	buf[1] = buf_size & 0xff;
373 	dprintk("Chosen link buffer size of %i\n", buf_size);
374 
375 	/* write the buffer size to the CAM */
376 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
377 					 IRQEN | CMDREG_SW);
378 	if (ret)
379 		return ret;
380 	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10);
381 	if (ret)
382 		return ret;
383 	ret = dvb_ca_en50221_write_data(ca, slot, buf, 2);
384 	if (ret != 2)
385 		return -EIO;
386 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
387 	if (ret)
388 		return ret;
389 
390 	/* success */
391 	return 0;
392 }
393 
394 /**
395  * dvb_ca_en50221_read_tuple - Read a tuple from attribute memory.
396  *
397  * @ca: CA instance.
398  * @slot: Slot id.
399  * @address: Address to read from. Updated.
400  * @tupleType: Tuple id byte. Updated.
401  * @tupleLength: Tuple length. Updated.
402  * @tuple: Dest buffer for tuple (must be 256 bytes). Updated.
403  *
404  * @return 0 on success, nonzero on error.
405  */
406 static int dvb_ca_en50221_read_tuple(struct dvb_ca_private *ca, int slot,
407 				     int *address, int *tuple_type,
408 				     int *tuple_length, u8 *tuple)
409 {
410 	int i;
411 	int _tuple_type;
412 	int _tuple_length;
413 	int _address = *address;
414 
415 	/* grab the next tuple length and type */
416 	_tuple_type = ca->pub->read_attribute_mem(ca->pub, slot, _address);
417 	if (_tuple_type < 0)
418 		return _tuple_type;
419 	if (_tuple_type == 0xff) {
420 		dprintk("END OF CHAIN TUPLE type:0x%x\n", _tuple_type);
421 		*address += 2;
422 		*tuple_type = _tuple_type;
423 		*tuple_length = 0;
424 		return 0;
425 	}
426 	_tuple_length = ca->pub->read_attribute_mem(ca->pub, slot,
427 						    _address + 2);
428 	if (_tuple_length < 0)
429 		return _tuple_length;
430 	_address += 4;
431 
432 	dprintk("TUPLE type:0x%x length:%i\n", _tuple_type, _tuple_length);
433 
434 	/* read in the whole tuple */
435 	for (i = 0; i < _tuple_length; i++) {
436 		tuple[i] = ca->pub->read_attribute_mem(ca->pub, slot,
437 						       _address + (i * 2));
438 		dprintk("  0x%02x: 0x%02x %c\n",
439 			i, tuple[i] & 0xff,
440 			((tuple[i] > 31) && (tuple[i] < 127)) ? tuple[i] : '.');
441 	}
442 	_address += (_tuple_length * 2);
443 
444 	/* success */
445 	*tuple_type = _tuple_type;
446 	*tuple_length = _tuple_length;
447 	*address = _address;
448 	return 0;
449 }
450 
451 /**
452  * dvb_ca_en50221_parse_attributes - Parse attribute memory of a CAM module,
453  *	extracting Config register, and checking it is a DVB CAM module.
454  *
455  * @ca: CA instance.
456  * @slot: Slot id.
457  *
458  * @return 0 on success, <0 on failure.
459  */
460 static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private *ca, int slot)
461 {
462 	struct dvb_ca_slot *sl;
463 	int address = 0;
464 	int tuple_length;
465 	int tuple_type;
466 	u8 tuple[257];
467 	char *dvb_str;
468 	int rasz;
469 	int status;
470 	int got_cftableentry = 0;
471 	int end_chain = 0;
472 	int i;
473 	u16 manfid = 0;
474 	u16 devid = 0;
475 
476 	/* CISTPL_DEVICE_0A */
477 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
478 					   &tuple_length, tuple);
479 	if (status < 0)
480 		return status;
481 	if (tuple_type != 0x1D)
482 		return -EINVAL;
483 
484 	/* CISTPL_DEVICE_0C */
485 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
486 					   &tuple_length, tuple);
487 	if (status < 0)
488 		return status;
489 	if (tuple_type != 0x1C)
490 		return -EINVAL;
491 
492 	/* CISTPL_VERS_1 */
493 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
494 					   &tuple_length, tuple);
495 	if (status < 0)
496 		return status;
497 	if (tuple_type != 0x15)
498 		return -EINVAL;
499 
500 	/* CISTPL_MANFID */
501 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
502 					   &tuple_length, tuple);
503 	if (status < 0)
504 		return status;
505 	if (tuple_type != 0x20)
506 		return -EINVAL;
507 	if (tuple_length != 4)
508 		return -EINVAL;
509 	manfid = (tuple[1] << 8) | tuple[0];
510 	devid = (tuple[3] << 8) | tuple[2];
511 
512 	/* CISTPL_CONFIG */
513 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
514 					   &tuple_length, tuple);
515 	if (status < 0)
516 		return status;
517 	if (tuple_type != 0x1A)
518 		return -EINVAL;
519 	if (tuple_length < 3)
520 		return -EINVAL;
521 
522 	/* extract the configbase */
523 	rasz = tuple[0] & 3;
524 	if (tuple_length < (3 + rasz + 14))
525 		return -EINVAL;
526 	sl = &ca->slot_info[slot];
527 	sl->config_base = 0;
528 	for (i = 0; i < rasz + 1; i++)
529 		sl->config_base |= (tuple[2 + i] << (8 * i));
530 
531 	/* check it contains the correct DVB string */
532 	dvb_str = findstr((char *)tuple, tuple_length, "DVB_CI_V", 8);
533 	if (!dvb_str)
534 		return -EINVAL;
535 	if (tuple_length < ((dvb_str - (char *)tuple) + 12))
536 		return -EINVAL;
537 
538 	/* is it a version we support? */
539 	if (strncmp(dvb_str + 8, "1.00", 4)) {
540 		pr_err("dvb_ca adapter %d: Unsupported DVB CAM module version %c%c%c%c\n",
541 		       ca->dvbdev->adapter->num, dvb_str[8], dvb_str[9],
542 		       dvb_str[10], dvb_str[11]);
543 		return -EINVAL;
544 	}
545 
546 	/* process the CFTABLE_ENTRY tuples, and any after those */
547 	while ((!end_chain) && (address < 0x1000)) {
548 		status = dvb_ca_en50221_read_tuple(ca, slot, &address,
549 						   &tuple_type, &tuple_length,
550 						   tuple);
551 		if (status < 0)
552 			return status;
553 		switch (tuple_type) {
554 		case 0x1B:	/* CISTPL_CFTABLE_ENTRY */
555 			if (tuple_length < (2 + 11 + 17))
556 				break;
557 
558 			/* if we've already parsed one, just use it */
559 			if (got_cftableentry)
560 				break;
561 
562 			/* get the config option */
563 			sl->config_option = tuple[0] & 0x3f;
564 
565 			/* OK, check it contains the correct strings */
566 			if (!findstr((char *)tuple, tuple_length,
567 				     "DVB_HOST", 8) ||
568 			    !findstr((char *)tuple, tuple_length,
569 				     "DVB_CI_MODULE", 13))
570 				break;
571 
572 			got_cftableentry = 1;
573 			break;
574 
575 		case 0x14:	/* CISTPL_NO_LINK */
576 			break;
577 
578 		case 0xFF:	/* CISTPL_END */
579 			end_chain = 1;
580 			break;
581 
582 		default:	/* Unknown tuple type - just skip this tuple */
583 			dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n",
584 				tuple_type, tuple_length);
585 			break;
586 		}
587 	}
588 
589 	if ((address > 0x1000) || (!got_cftableentry))
590 		return -EINVAL;
591 
592 	dprintk("Valid DVB CAM detected MANID:%x DEVID:%x CONFIGBASE:0x%x CONFIGOPTION:0x%x\n",
593 		manfid, devid, sl->config_base, sl->config_option);
594 
595 	/* success! */
596 	return 0;
597 }
598 
599 /**
600  * dvb_ca_en50221_set_configoption - Set CAM's configoption correctly.
601  *
602  * @ca: CA instance.
603  * @slot: Slot containing the CAM.
604  */
605 static int dvb_ca_en50221_set_configoption(struct dvb_ca_private *ca, int slot)
606 {
607 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
608 	int configoption;
609 
610 	dprintk("%s\n", __func__);
611 
612 	/* set the config option */
613 	ca->pub->write_attribute_mem(ca->pub, slot, sl->config_base,
614 				     sl->config_option);
615 
616 	/* check it */
617 	configoption = ca->pub->read_attribute_mem(ca->pub, slot,
618 						   sl->config_base);
619 	dprintk("Set configoption 0x%x, read configoption 0x%x\n",
620 		sl->config_option, configoption & 0x3f);
621 
622 	/* fine! */
623 	return 0;
624 }
625 
626 /**
627  * dvb_ca_en50221_read_data - This function talks to an EN50221 CAM control
628  *	interface. It reads a buffer of data from the CAM. The data can either
629  *	be stored in a supplied buffer, or automatically be added to the slot's
630  *	rx_buffer.
631  *
632  * @ca: CA instance.
633  * @slot: Slot to read from.
634  * @ebuf: If non-NULL, the data will be written to this buffer. If NULL,
635  * the data will be added into the buffering system as a normal fragment.
636  * @ecount: Size of ebuf. Ignored if ebuf is NULL.
637  *
638  * @return Number of bytes read, or < 0 on error
639  */
640 static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
641 				    u8 *ebuf, int ecount)
642 {
643 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
644 	int bytes_read;
645 	int status;
646 	u8 buf[HOST_LINK_BUF_SIZE];
647 	int i;
648 
649 	dprintk("%s\n", __func__);
650 
651 	/* check if we have space for a link buf in the rx_buffer */
652 	if (!ebuf) {
653 		int buf_free;
654 
655 		if (!sl->rx_buffer.data) {
656 			status = -EIO;
657 			goto exit;
658 		}
659 		buf_free = dvb_ringbuffer_free(&sl->rx_buffer);
660 
661 		if (buf_free < (sl->link_buf_size +
662 				DVB_RINGBUFFER_PKTHDRSIZE)) {
663 			status = -EAGAIN;
664 			goto exit;
665 		}
666 	}
667 
668 	if (ca->pub->read_data &&
669 	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT)) {
670 		if (!ebuf)
671 			status = ca->pub->read_data(ca->pub, slot, buf,
672 						    sizeof(buf));
673 		else
674 			status = ca->pub->read_data(ca->pub, slot, buf, ecount);
675 		if (status < 0)
676 			return status;
677 		bytes_read =  status;
678 		if (status == 0)
679 			goto exit;
680 	} else {
681 		/* check if there is data available */
682 		status = ca->pub->read_cam_control(ca->pub, slot,
683 						   CTRLIF_STATUS);
684 		if (status < 0)
685 			goto exit;
686 		if (!(status & STATUSREG_DA)) {
687 			/* no data */
688 			status = 0;
689 			goto exit;
690 		}
691 
692 		/* read the amount of data */
693 		status = ca->pub->read_cam_control(ca->pub, slot,
694 						   CTRLIF_SIZE_HIGH);
695 		if (status < 0)
696 			goto exit;
697 		bytes_read = status << 8;
698 		status = ca->pub->read_cam_control(ca->pub, slot,
699 						   CTRLIF_SIZE_LOW);
700 		if (status < 0)
701 			goto exit;
702 		bytes_read |= status;
703 
704 		/* check it will fit */
705 		if (!ebuf) {
706 			if (bytes_read > sl->link_buf_size) {
707 				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the link buffer size (%i > %i)!\n",
708 				       ca->dvbdev->adapter->num, bytes_read,
709 				       sl->link_buf_size);
710 				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
711 				status = -EIO;
712 				goto exit;
713 			}
714 			if (bytes_read < 2) {
715 				pr_err("dvb_ca adapter %d: CAM sent a buffer that was less than 2 bytes!\n",
716 				       ca->dvbdev->adapter->num);
717 				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
718 				status = -EIO;
719 				goto exit;
720 			}
721 		} else {
722 			if (bytes_read > ecount) {
723 				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the ecount size!\n",
724 				       ca->dvbdev->adapter->num);
725 				status = -EIO;
726 				goto exit;
727 			}
728 		}
729 
730 		/* fill the buffer */
731 		for (i = 0; i < bytes_read; i++) {
732 			/* read byte and check */
733 			status = ca->pub->read_cam_control(ca->pub, slot,
734 							   CTRLIF_DATA);
735 			if (status < 0)
736 				goto exit;
737 
738 			/* OK, store it in the buffer */
739 			buf[i] = status;
740 		}
741 
742 		/* check for read error (RE should now be 0) */
743 		status = ca->pub->read_cam_control(ca->pub, slot,
744 						   CTRLIF_STATUS);
745 		if (status < 0)
746 			goto exit;
747 		if (status & STATUSREG_RE) {
748 			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
749 			status = -EIO;
750 			goto exit;
751 		}
752 	}
753 
754 	/*
755 	 * OK, add it to the receive buffer, or copy into external buffer if
756 	 * supplied
757 	 */
758 	if (!ebuf) {
759 		if (!sl->rx_buffer.data) {
760 			status = -EIO;
761 			goto exit;
762 		}
763 		dvb_ringbuffer_pkt_write(&sl->rx_buffer, buf, bytes_read);
764 	} else {
765 		memcpy(ebuf, buf, bytes_read);
766 	}
767 
768 	dprintk("Received CA packet for slot %i connection id 0x%x last_frag:%i size:0x%x\n", slot,
769 		buf[0], (buf[1] & 0x80) == 0, bytes_read);
770 
771 	/* wake up readers when a last_fragment is received */
772 	if ((buf[1] & 0x80) == 0x00)
773 		wake_up_interruptible(&ca->wait_queue);
774 
775 	status = bytes_read;
776 
777 exit:
778 	return status;
779 }
780 
781 /**
782  * dvb_ca_en50221_write_data - This function talks to an EN50221 CAM control
783  *				interface. It writes a buffer of data to a CAM.
784  *
785  * @ca: CA instance.
786  * @slot: Slot to write to.
787  * @ebuf: The data in this buffer is treated as a complete link-level packet to
788  * be written.
789  * @count: Size of ebuf.
790  *
791  * @return Number of bytes written, or < 0 on error.
792  */
793 static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
794 				     u8 *buf, int bytes_write)
795 {
796 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
797 	int status;
798 	int i;
799 
800 	dprintk("%s\n", __func__);
801 
802 	/* sanity check */
803 	if (bytes_write > sl->link_buf_size)
804 		return -EINVAL;
805 
806 	if (ca->pub->write_data &&
807 	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT))
808 		return ca->pub->write_data(ca->pub, slot, buf, bytes_write);
809 
810 	/*
811 	 * it is possible we are dealing with a single buffer implementation,
812 	 * thus if there is data available for read or if there is even a read
813 	 * already in progress, we do nothing but awake the kernel thread to
814 	 * process the data if necessary.
815 	 */
816 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
817 	if (status < 0)
818 		goto exitnowrite;
819 	if (status & (STATUSREG_DA | STATUSREG_RE)) {
820 		if (status & STATUSREG_DA)
821 			dvb_ca_en50221_thread_wakeup(ca);
822 
823 		status = -EAGAIN;
824 		goto exitnowrite;
825 	}
826 
827 	/* OK, set HC bit */
828 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
829 					    IRQEN | CMDREG_HC);
830 	if (status)
831 		goto exit;
832 
833 	/* check if interface is still free */
834 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
835 	if (status < 0)
836 		goto exit;
837 	if (!(status & STATUSREG_FR)) {
838 		/* it wasn't free => try again later */
839 		status = -EAGAIN;
840 		goto exit;
841 	}
842 
843 	/*
844 	 * It may need some time for the CAM to settle down, or there might
845 	 * be a race condition between the CAM, writing HC and our last
846 	 * check for DA. This happens, if the CAM asserts DA, just after
847 	 * checking DA before we are setting HC. In this case it might be
848 	 * a bug in the CAM to keep the FR bit, the lower layer/HW
849 	 * communication requires a longer timeout or the CAM needs more
850 	 * time internally. But this happens in reality!
851 	 * We need to read the status from the HW again and do the same
852 	 * we did for the previous check for DA
853 	 */
854 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
855 	if (status < 0)
856 		goto exit;
857 
858 	if (status & (STATUSREG_DA | STATUSREG_RE)) {
859 		if (status & STATUSREG_DA)
860 			dvb_ca_en50221_thread_wakeup(ca);
861 
862 		status = -EAGAIN;
863 		goto exit;
864 	}
865 
866 	/* send the amount of data */
867 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH,
868 					    bytes_write >> 8);
869 	if (status)
870 		goto exit;
871 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW,
872 					    bytes_write & 0xff);
873 	if (status)
874 		goto exit;
875 
876 	/* send the buffer */
877 	for (i = 0; i < bytes_write; i++) {
878 		status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA,
879 						    buf[i]);
880 		if (status)
881 			goto exit;
882 	}
883 
884 	/* check for write error (WE should now be 0) */
885 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
886 	if (status < 0)
887 		goto exit;
888 	if (status & STATUSREG_WE) {
889 		sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
890 		status = -EIO;
891 		goto exit;
892 	}
893 	status = bytes_write;
894 
895 	dprintk("Wrote CA packet for slot %i, connection id 0x%x last_frag:%i size:0x%x\n", slot,
896 		buf[0], (buf[1] & 0x80) == 0, bytes_write);
897 
898 exit:
899 	ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
900 
901 exitnowrite:
902 	return status;
903 }
904 
905 /* ************************************************************************** */
906 /* EN50221 higher level functions */
907 
908 /**
909  * dvb_ca_en50221_slot_shutdown - A CAM has been removed => shut it down.
910  *
911  * @ca: CA instance.
912  * @slot: Slot to shut down.
913  */
914 static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private *ca, int slot)
915 {
916 	dprintk("%s\n", __func__);
917 
918 	ca->pub->slot_shutdown(ca->pub, slot);
919 	ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
920 
921 	/*
922 	 * need to wake up all processes to check if they're now trying to
923 	 * write to a defunct CAM
924 	 */
925 	wake_up_interruptible(&ca->wait_queue);
926 
927 	dprintk("Slot %i shutdown\n", slot);
928 
929 	/* success */
930 	return 0;
931 }
932 
933 /**
934  * dvb_ca_en50221_camchange_irq - A CAMCHANGE IRQ has occurred.
935  *
936  * @ca: CA instance.
937  * @slot: Slot concerned.
938  * @change_type: One of the DVB_CA_CAMCHANGE_* values.
939  */
940 void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221 *pubca, int slot,
941 				  int change_type)
942 {
943 	struct dvb_ca_private *ca = pubca->private;
944 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
945 
946 	dprintk("CAMCHANGE IRQ slot:%i change_type:%i\n", slot, change_type);
947 
948 	switch (change_type) {
949 	case DVB_CA_EN50221_CAMCHANGE_REMOVED:
950 	case DVB_CA_EN50221_CAMCHANGE_INSERTED:
951 		break;
952 
953 	default:
954 		return;
955 	}
956 
957 	sl->camchange_type = change_type;
958 	atomic_inc(&sl->camchange_count);
959 	dvb_ca_en50221_thread_wakeup(ca);
960 }
961 EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);
962 
963 /**
964  * dvb_ca_en50221_camready_irq - A CAMREADY IRQ has occurred.
965  *
966  * @ca: CA instance.
967  * @slot: Slot concerned.
968  */
969 void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 *pubca, int slot)
970 {
971 	struct dvb_ca_private *ca = pubca->private;
972 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
973 
974 	dprintk("CAMREADY IRQ slot:%i\n", slot);
975 
976 	if (sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
977 		sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
978 		dvb_ca_en50221_thread_wakeup(ca);
979 	}
980 }
981 EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);
982 
983 /**
984  * dvb_ca_en50221_frda_irq - An FR or DA IRQ has occurred.
985  *
986  * @ca: CA instance.
987  * @slot: Slot concerned.
988  */
989 void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
990 {
991 	struct dvb_ca_private *ca = pubca->private;
992 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
993 	int flags;
994 
995 	dprintk("FR/DA IRQ slot:%i\n", slot);
996 
997 	switch (sl->slot_state) {
998 	case DVB_CA_SLOTSTATE_LINKINIT:
999 		flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
1000 		if (flags & STATUSREG_DA) {
1001 			dprintk("CAM supports DA IRQ\n");
1002 			sl->da_irq_supported = 1;
1003 		}
1004 		break;
1005 
1006 	case DVB_CA_SLOTSTATE_RUNNING:
1007 		if (ca->open)
1008 			dvb_ca_en50221_thread_wakeup(ca);
1009 		break;
1010 	}
1011 }
1012 EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);
1013 
1014 /* ************************************************************************** */
1015 /* EN50221 thread functions */
1016 
1017 /**
1018  * Wake up the DVB CA thread
1019  *
1020  * @ca: CA instance.
1021  */
1022 static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca)
1023 {
1024 	dprintk("%s\n", __func__);
1025 
1026 	ca->wakeup = 1;
1027 	mb();
1028 	wake_up_process(ca->thread);
1029 }
1030 
1031 /**
1032  * Update the delay used by the thread.
1033  *
1034  * @ca: CA instance.
1035  */
1036 static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private *ca)
1037 {
1038 	int delay;
1039 	int curdelay = 100000000;
1040 	int slot;
1041 
1042 	/*
1043 	 * Beware of too high polling frequency, because one polling
1044 	 * call might take several hundred milliseconds until timeout!
1045 	 */
1046 	for (slot = 0; slot < ca->slot_count; slot++) {
1047 		struct dvb_ca_slot *sl = &ca->slot_info[slot];
1048 
1049 		switch (sl->slot_state) {
1050 		default:
1051 		case DVB_CA_SLOTSTATE_NONE:
1052 			delay = HZ * 60;  /* 60s */
1053 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1054 				delay = HZ * 5;  /* 5s */
1055 			break;
1056 		case DVB_CA_SLOTSTATE_INVALID:
1057 			delay = HZ * 60;  /* 60s */
1058 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1059 				delay = HZ / 10;  /* 100ms */
1060 			break;
1061 
1062 		case DVB_CA_SLOTSTATE_UNINITIALISED:
1063 		case DVB_CA_SLOTSTATE_WAITREADY:
1064 		case DVB_CA_SLOTSTATE_VALIDATE:
1065 		case DVB_CA_SLOTSTATE_WAITFR:
1066 		case DVB_CA_SLOTSTATE_LINKINIT:
1067 			delay = HZ / 10;  /* 100ms */
1068 			break;
1069 
1070 		case DVB_CA_SLOTSTATE_RUNNING:
1071 			delay = HZ * 60;  /* 60s */
1072 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1073 				delay = HZ / 10;  /* 100ms */
1074 			if (ca->open) {
1075 				if ((!sl->da_irq_supported) ||
1076 				    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA)))
1077 					delay = HZ / 10;  /* 100ms */
1078 			}
1079 			break;
1080 		}
1081 
1082 		if (delay < curdelay)
1083 			curdelay = delay;
1084 	}
1085 
1086 	ca->delay = curdelay;
1087 }
1088 
1089 /**
1090  * Poll if the CAM is gone.
1091  *
1092  * @ca: CA instance.
1093  * @slot: Slot to process.
1094  * @return: 0 .. no change
1095  *          1 .. CAM state changed
1096  */
1097 
1098 static int dvb_ca_en50221_poll_cam_gone(struct dvb_ca_private *ca, int slot)
1099 {
1100 	int changed = 0;
1101 	int status;
1102 
1103 	/*
1104 	 * we need this extra check for annoying interfaces like the
1105 	 * budget-av
1106 	 */
1107 	if ((!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) &&
1108 	    (ca->pub->poll_slot_status)) {
1109 		status = ca->pub->poll_slot_status(ca->pub, slot, 0);
1110 		if (!(status &
1111 			DVB_CA_EN50221_POLL_CAM_PRESENT)) {
1112 			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
1113 			dvb_ca_en50221_thread_update_delay(ca);
1114 			changed = 1;
1115 		}
1116 	}
1117 	return changed;
1118 }
1119 
1120 /**
1121  * Thread state machine for one CA slot to perform the data transfer.
1122  *
1123  * @ca: CA instance.
1124  * @slot: Slot to process.
1125  */
1126 static void dvb_ca_en50221_thread_state_machine(struct dvb_ca_private *ca,
1127 						int slot)
1128 {
1129 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
1130 	int flags;
1131 	int pktcount;
1132 	void *rxbuf;
1133 
1134 	mutex_lock(&sl->slot_lock);
1135 
1136 	/* check the cam status + deal with CAMCHANGEs */
1137 	while (dvb_ca_en50221_check_camstatus(ca, slot)) {
1138 		/* clear down an old CI slot if necessary */
1139 		if (sl->slot_state != DVB_CA_SLOTSTATE_NONE)
1140 			dvb_ca_en50221_slot_shutdown(ca, slot);
1141 
1142 		/* if a CAM is NOW present, initialise it */
1143 		if (sl->camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED)
1144 			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
1145 
1146 		/* we've handled one CAMCHANGE */
1147 		dvb_ca_en50221_thread_update_delay(ca);
1148 		atomic_dec(&sl->camchange_count);
1149 	}
1150 
1151 	/* CAM state machine */
1152 	switch (sl->slot_state) {
1153 	case DVB_CA_SLOTSTATE_NONE:
1154 	case DVB_CA_SLOTSTATE_INVALID:
1155 		/* no action needed */
1156 		break;
1157 
1158 	case DVB_CA_SLOTSTATE_UNINITIALISED:
1159 		sl->slot_state = DVB_CA_SLOTSTATE_WAITREADY;
1160 		ca->pub->slot_reset(ca->pub, slot);
1161 		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
1162 		break;
1163 
1164 	case DVB_CA_SLOTSTATE_WAITREADY:
1165 		if (time_after(jiffies, sl->timeout)) {
1166 			pr_err("dvb_ca adaptor %d: PC card did not respond :(\n",
1167 			       ca->dvbdev->adapter->num);
1168 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1169 			dvb_ca_en50221_thread_update_delay(ca);
1170 			break;
1171 		}
1172 		/*
1173 		 * no other action needed; will automatically change state when
1174 		 * ready
1175 		 */
1176 		break;
1177 
1178 	case DVB_CA_SLOTSTATE_VALIDATE:
1179 		if (dvb_ca_en50221_parse_attributes(ca, slot) != 0) {
1180 			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
1181 				break;
1182 
1183 			pr_err("dvb_ca adapter %d: Invalid PC card inserted :(\n",
1184 			       ca->dvbdev->adapter->num);
1185 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1186 			dvb_ca_en50221_thread_update_delay(ca);
1187 			break;
1188 		}
1189 		if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
1190 			pr_err("dvb_ca adapter %d: Unable to initialise CAM :(\n",
1191 			       ca->dvbdev->adapter->num);
1192 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1193 			dvb_ca_en50221_thread_update_delay(ca);
1194 			break;
1195 		}
1196 		if (ca->pub->write_cam_control(ca->pub, slot,
1197 					       CTRLIF_COMMAND,
1198 					       CMDREG_RS) != 0) {
1199 			pr_err("dvb_ca adapter %d: Unable to reset CAM IF\n",
1200 			       ca->dvbdev->adapter->num);
1201 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1202 			dvb_ca_en50221_thread_update_delay(ca);
1203 			break;
1204 		}
1205 		dprintk("DVB CAM validated successfully\n");
1206 
1207 		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
1208 		sl->slot_state = DVB_CA_SLOTSTATE_WAITFR;
1209 		ca->wakeup = 1;
1210 		break;
1211 
1212 	case DVB_CA_SLOTSTATE_WAITFR:
1213 		if (time_after(jiffies, sl->timeout)) {
1214 			pr_err("dvb_ca adapter %d: DVB CAM did not respond :(\n",
1215 			       ca->dvbdev->adapter->num);
1216 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1217 			dvb_ca_en50221_thread_update_delay(ca);
1218 			break;
1219 		}
1220 
1221 		flags = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
1222 		if (flags & STATUSREG_FR) {
1223 			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
1224 			ca->wakeup = 1;
1225 		}
1226 		break;
1227 
1228 	case DVB_CA_SLOTSTATE_LINKINIT:
1229 		if (dvb_ca_en50221_link_init(ca, slot) != 0) {
1230 			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
1231 				break;
1232 
1233 			pr_err("dvb_ca adapter %d: DVB CAM link initialisation failed :(\n",
1234 			       ca->dvbdev->adapter->num);
1235 			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
1236 			dvb_ca_en50221_thread_update_delay(ca);
1237 			break;
1238 		}
1239 
1240 		if (!sl->rx_buffer.data) {
1241 			rxbuf = vmalloc(RX_BUFFER_SIZE);
1242 			if (!rxbuf) {
1243 				pr_err("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n",
1244 				       ca->dvbdev->adapter->num);
1245 				sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1246 				dvb_ca_en50221_thread_update_delay(ca);
1247 				break;
1248 			}
1249 			dvb_ringbuffer_init(&sl->rx_buffer, rxbuf,
1250 					    RX_BUFFER_SIZE);
1251 		}
1252 
1253 		ca->pub->slot_ts_enable(ca->pub, slot);
1254 		sl->slot_state = DVB_CA_SLOTSTATE_RUNNING;
1255 		dvb_ca_en50221_thread_update_delay(ca);
1256 		pr_err("dvb_ca adapter %d: DVB CAM detected and initialised successfully\n",
1257 		       ca->dvbdev->adapter->num);
1258 		break;
1259 
1260 	case DVB_CA_SLOTSTATE_RUNNING:
1261 		if (!ca->open)
1262 			break;
1263 
1264 		/* poll slots for data */
1265 		pktcount = 0;
1266 		while (dvb_ca_en50221_read_data(ca, slot, NULL, 0) > 0) {
1267 			if (!ca->open)
1268 				break;
1269 
1270 			/*
1271 			 * if a CAMCHANGE occurred at some point, do not do any
1272 			 * more processing of this slot
1273 			 */
1274 			if (dvb_ca_en50221_check_camstatus(ca, slot)) {
1275 				/*
1276 				 * we don't want to sleep on the next iteration
1277 				 * so we can handle the cam change
1278 				 */
1279 				ca->wakeup = 1;
1280 				break;
1281 			}
1282 
1283 			/* check if we've hit our limit this time */
1284 			if (++pktcount >= MAX_RX_PACKETS_PER_ITERATION) {
1285 				/*
1286 				 * don't sleep; there is likely to be more data
1287 				 * to read
1288 				 */
1289 				ca->wakeup = 1;
1290 				break;
1291 			}
1292 		}
1293 		break;
1294 	}
1295 
1296 	mutex_unlock(&sl->slot_lock);
1297 }
1298 
1299 /**
1300  * Kernel thread which monitors CA slots for CAM changes, and performs data
1301  * transfers.
1302  */
1303 static int dvb_ca_en50221_thread(void *data)
1304 {
1305 	struct dvb_ca_private *ca = data;
1306 	int slot;
1307 
1308 	dprintk("%s\n", __func__);
1309 
1310 	/* choose the correct initial delay */
1311 	dvb_ca_en50221_thread_update_delay(ca);
1312 
1313 	/* main loop */
1314 	while (!kthread_should_stop()) {
1315 		/* sleep for a bit */
1316 		if (!ca->wakeup) {
1317 			set_current_state(TASK_INTERRUPTIBLE);
1318 			schedule_timeout(ca->delay);
1319 			if (kthread_should_stop())
1320 				return 0;
1321 		}
1322 		ca->wakeup = 0;
1323 
1324 		/* go through all the slots processing them */
1325 		for (slot = 0; slot < ca->slot_count; slot++)
1326 			dvb_ca_en50221_thread_state_machine(ca, slot);
1327 	}
1328 
1329 	return 0;
1330 }
1331 
1332 /* ************************************************************************** */
1333 /* EN50221 IO interface functions */
1334 
1335 /**
1336  * Real ioctl implementation.
1337  * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
1338  *
1339  * @inode: Inode concerned.
1340  * @file: File concerned.
1341  * @cmd: IOCTL command.
1342  * @arg: Associated argument.
1343  *
1344  * @return 0 on success, <0 on error.
1345  */
1346 static int dvb_ca_en50221_io_do_ioctl(struct file *file,
1347 				      unsigned int cmd, void *parg)
1348 {
1349 	struct dvb_device *dvbdev = file->private_data;
1350 	struct dvb_ca_private *ca = dvbdev->priv;
1351 	int err = 0;
1352 	int slot;
1353 
1354 	dprintk("%s\n", __func__);
1355 
1356 	if (mutex_lock_interruptible(&ca->ioctl_mutex))
1357 		return -ERESTARTSYS;
1358 
1359 	switch (cmd) {
1360 	case CA_RESET:
1361 		for (slot = 0; slot < ca->slot_count; slot++) {
1362 			struct dvb_ca_slot *sl = &ca->slot_info[slot];
1363 
1364 			mutex_lock(&sl->slot_lock);
1365 			if (sl->slot_state != DVB_CA_SLOTSTATE_NONE) {
1366 				dvb_ca_en50221_slot_shutdown(ca, slot);
1367 				if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
1368 					dvb_ca_en50221_camchange_irq(ca->pub,
1369 								     slot,
1370 								     DVB_CA_EN50221_CAMCHANGE_INSERTED);
1371 			}
1372 			mutex_unlock(&sl->slot_lock);
1373 		}
1374 		ca->next_read_slot = 0;
1375 		dvb_ca_en50221_thread_wakeup(ca);
1376 		break;
1377 
1378 	case CA_GET_CAP: {
1379 		struct ca_caps *caps = parg;
1380 
1381 		caps->slot_num = ca->slot_count;
1382 		caps->slot_type = CA_CI_LINK;
1383 		caps->descr_num = 0;
1384 		caps->descr_type = 0;
1385 		break;
1386 	}
1387 
1388 	case CA_GET_SLOT_INFO: {
1389 		struct ca_slot_info *info = parg;
1390 		struct dvb_ca_slot *sl;
1391 
1392 		slot = info->num;
1393 		if ((slot > ca->slot_count) || (slot < 0)) {
1394 			err = -EINVAL;
1395 			goto out_unlock;
1396 		}
1397 
1398 		info->type = CA_CI_LINK;
1399 		info->flags = 0;
1400 		sl = &ca->slot_info[slot];
1401 		if ((sl->slot_state != DVB_CA_SLOTSTATE_NONE) &&
1402 		    (sl->slot_state != DVB_CA_SLOTSTATE_INVALID)) {
1403 			info->flags = CA_CI_MODULE_PRESENT;
1404 		}
1405 		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING)
1406 			info->flags |= CA_CI_MODULE_READY;
1407 		break;
1408 	}
1409 
1410 	default:
1411 		err = -EINVAL;
1412 		break;
1413 	}
1414 
1415 out_unlock:
1416 	mutex_unlock(&ca->ioctl_mutex);
1417 	return err;
1418 }
1419 
1420 /**
1421  * Wrapper for ioctl implementation.
1422  *
1423  * @inode: Inode concerned.
1424  * @file: File concerned.
1425  * @cmd: IOCTL command.
1426  * @arg: Associated argument.
1427  *
1428  * @return 0 on success, <0 on error.
1429  */
1430 static long dvb_ca_en50221_io_ioctl(struct file *file,
1431 				    unsigned int cmd, unsigned long arg)
1432 {
1433 	return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
1434 }
1435 
1436 /**
1437  * Implementation of write() syscall.
1438  *
1439  * @file: File structure.
1440  * @buf: Source buffer.
1441  * @count: Size of source buffer.
1442  * @ppos: Position in file (ignored).
1443  *
1444  * @return Number of bytes read, or <0 on error.
1445  */
1446 static ssize_t dvb_ca_en50221_io_write(struct file *file,
1447 				       const char __user *buf, size_t count,
1448 				       loff_t *ppos)
1449 {
1450 	struct dvb_device *dvbdev = file->private_data;
1451 	struct dvb_ca_private *ca = dvbdev->priv;
1452 	struct dvb_ca_slot *sl;
1453 	u8 slot, connection_id;
1454 	int status;
1455 	u8 fragbuf[HOST_LINK_BUF_SIZE];
1456 	int fragpos = 0;
1457 	int fraglen;
1458 	unsigned long timeout;
1459 	int written;
1460 
1461 	dprintk("%s\n", __func__);
1462 
1463 	/*
1464 	 * Incoming packet has a 2 byte header.
1465 	 * hdr[0] = slot_id, hdr[1] = connection_id
1466 	 */
1467 	if (count < 2)
1468 		return -EINVAL;
1469 
1470 	/* extract slot & connection id */
1471 	if (copy_from_user(&slot, buf, 1))
1472 		return -EFAULT;
1473 	if (copy_from_user(&connection_id, buf + 1, 1))
1474 		return -EFAULT;
1475 	buf += 2;
1476 	count -= 2;
1477 	sl = &ca->slot_info[slot];
1478 
1479 	/* check if the slot is actually running */
1480 	if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
1481 		return -EINVAL;
1482 
1483 	/* fragment the packets & store in the buffer */
1484 	while (fragpos < count) {
1485 		fraglen = sl->link_buf_size - 2;
1486 		if (fraglen < 0)
1487 			break;
1488 		if (fraglen > HOST_LINK_BUF_SIZE - 2)
1489 			fraglen = HOST_LINK_BUF_SIZE - 2;
1490 		if ((count - fragpos) < fraglen)
1491 			fraglen = count - fragpos;
1492 
1493 		fragbuf[0] = connection_id;
1494 		fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
1495 		status = copy_from_user(fragbuf + 2, buf + fragpos, fraglen);
1496 		if (status) {
1497 			status = -EFAULT;
1498 			goto exit;
1499 		}
1500 
1501 		timeout = jiffies + HZ / 2;
1502 		written = 0;
1503 		while (!time_after(jiffies, timeout)) {
1504 			/*
1505 			 * check the CAM hasn't been removed/reset in the
1506 			 * meantime
1507 			 */
1508 			if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING) {
1509 				status = -EIO;
1510 				goto exit;
1511 			}
1512 
1513 			mutex_lock(&sl->slot_lock);
1514 			status = dvb_ca_en50221_write_data(ca, slot, fragbuf,
1515 							   fraglen + 2);
1516 			mutex_unlock(&sl->slot_lock);
1517 			if (status == (fraglen + 2)) {
1518 				written = 1;
1519 				break;
1520 			}
1521 			if (status != -EAGAIN)
1522 				goto exit;
1523 
1524 			usleep_range(1000, 1100);
1525 		}
1526 		if (!written) {
1527 			status = -EIO;
1528 			goto exit;
1529 		}
1530 
1531 		fragpos += fraglen;
1532 	}
1533 	status = count + 2;
1534 
1535 exit:
1536 	return status;
1537 }
1538 
1539 /**
1540  * Condition for waking up in dvb_ca_en50221_io_read_condition
1541  */
1542 static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
1543 					    int *result, int *_slot)
1544 {
1545 	int slot;
1546 	int slot_count = 0;
1547 	int idx;
1548 	size_t fraglen;
1549 	int connection_id = -1;
1550 	int found = 0;
1551 	u8 hdr[2];
1552 
1553 	slot = ca->next_read_slot;
1554 	while ((slot_count < ca->slot_count) && (!found)) {
1555 		struct dvb_ca_slot *sl = &ca->slot_info[slot];
1556 
1557 		if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
1558 			goto nextslot;
1559 
1560 		if (!sl->rx_buffer.data)
1561 			return 0;
1562 
1563 		idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
1564 		while (idx != -1) {
1565 			dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
1566 			if (connection_id == -1)
1567 				connection_id = hdr[0];
1568 			if ((hdr[0] == connection_id) &&
1569 			    ((hdr[1] & 0x80) == 0)) {
1570 				*_slot = slot;
1571 				found = 1;
1572 				break;
1573 			}
1574 
1575 			idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx,
1576 						      &fraglen);
1577 		}
1578 
1579 nextslot:
1580 		slot = (slot + 1) % ca->slot_count;
1581 		slot_count++;
1582 	}
1583 
1584 	ca->next_read_slot = slot;
1585 	return found;
1586 }
1587 
1588 /**
1589  * Implementation of read() syscall.
1590  *
1591  * @file: File structure.
1592  * @buf: Destination buffer.
1593  * @count: Size of destination buffer.
1594  * @ppos: Position in file (ignored).
1595  *
1596  * @return Number of bytes read, or <0 on error.
1597  */
1598 static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user *buf,
1599 				      size_t count, loff_t *ppos)
1600 {
1601 	struct dvb_device *dvbdev = file->private_data;
1602 	struct dvb_ca_private *ca = dvbdev->priv;
1603 	struct dvb_ca_slot *sl;
1604 	int status;
1605 	int result = 0;
1606 	u8 hdr[2];
1607 	int slot;
1608 	int connection_id = -1;
1609 	size_t idx, idx2;
1610 	int last_fragment = 0;
1611 	size_t fraglen;
1612 	int pktlen;
1613 	int dispose = 0;
1614 
1615 	dprintk("%s\n", __func__);
1616 
1617 	/*
1618 	 * Outgoing packet has a 2 byte header.
1619 	 * hdr[0] = slot_id, hdr[1] = connection_id
1620 	 */
1621 	if (count < 2)
1622 		return -EINVAL;
1623 
1624 	/* wait for some data */
1625 	status = dvb_ca_en50221_io_read_condition(ca, &result, &slot);
1626 	if (status == 0) {
1627 		/* if we're in nonblocking mode, exit immediately */
1628 		if (file->f_flags & O_NONBLOCK)
1629 			return -EWOULDBLOCK;
1630 
1631 		/* wait for some data */
1632 		status = wait_event_interruptible(ca->wait_queue,
1633 						  dvb_ca_en50221_io_read_condition
1634 						  (ca, &result, &slot));
1635 	}
1636 	if ((status < 0) || (result < 0)) {
1637 		if (result)
1638 			return result;
1639 		return status;
1640 	}
1641 
1642 	sl = &ca->slot_info[slot];
1643 	idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
1644 	pktlen = 2;
1645 	do {
1646 		if (idx == -1) {
1647 			pr_err("dvb_ca adapter %d: BUG: read packet ended before last_fragment encountered\n",
1648 			       ca->dvbdev->adapter->num);
1649 			status = -EIO;
1650 			goto exit;
1651 		}
1652 
1653 		dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
1654 		if (connection_id == -1)
1655 			connection_id = hdr[0];
1656 		if (hdr[0] == connection_id) {
1657 			if (pktlen < count) {
1658 				if ((pktlen + fraglen - 2) > count)
1659 					fraglen = count - pktlen;
1660 				else
1661 					fraglen -= 2;
1662 
1663 				status =
1664 				   dvb_ringbuffer_pkt_read_user(&sl->rx_buffer,
1665 								idx, 2,
1666 								buf + pktlen,
1667 								fraglen);
1668 				if (status < 0)
1669 					goto exit;
1670 
1671 				pktlen += fraglen;
1672 			}
1673 
1674 			if ((hdr[1] & 0x80) == 0)
1675 				last_fragment = 1;
1676 			dispose = 1;
1677 		}
1678 
1679 		idx2 = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx, &fraglen);
1680 		if (dispose)
1681 			dvb_ringbuffer_pkt_dispose(&sl->rx_buffer, idx);
1682 		idx = idx2;
1683 		dispose = 0;
1684 	} while (!last_fragment);
1685 
1686 	hdr[0] = slot;
1687 	hdr[1] = connection_id;
1688 	status = copy_to_user(buf, hdr, 2);
1689 	if (status) {
1690 		status = -EFAULT;
1691 		goto exit;
1692 	}
1693 	status = pktlen;
1694 
1695 exit:
1696 	return status;
1697 }
1698 
1699 /**
1700  * Implementation of file open syscall.
1701  *
1702  * @inode: Inode concerned.
1703  * @file: File concerned.
1704  *
1705  * @return 0 on success, <0 on failure.
1706  */
1707 static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
1708 {
1709 	struct dvb_device *dvbdev = file->private_data;
1710 	struct dvb_ca_private *ca = dvbdev->priv;
1711 	int err;
1712 	int i;
1713 
1714 	dprintk("%s\n", __func__);
1715 
1716 	if (!try_module_get(ca->pub->owner))
1717 		return -EIO;
1718 
1719 	err = dvb_generic_open(inode, file);
1720 	if (err < 0) {
1721 		module_put(ca->pub->owner);
1722 		return err;
1723 	}
1724 
1725 	for (i = 0; i < ca->slot_count; i++) {
1726 		struct dvb_ca_slot *sl = &ca->slot_info[i];
1727 
1728 		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING) {
1729 			if (!sl->rx_buffer.data) {
1730 				/*
1731 				 * it is safe to call this here without locks
1732 				 * because ca->open == 0. Data is not read in
1733 				 * this case
1734 				 */
1735 				dvb_ringbuffer_flush(&sl->rx_buffer);
1736 			}
1737 		}
1738 	}
1739 
1740 	ca->open = 1;
1741 	dvb_ca_en50221_thread_update_delay(ca);
1742 	dvb_ca_en50221_thread_wakeup(ca);
1743 
1744 	dvb_ca_private_get(ca);
1745 
1746 	return 0;
1747 }
1748 
1749 /**
1750  * Implementation of file close syscall.
1751  *
1752  * @inode: Inode concerned.
1753  * @file: File concerned.
1754  *
1755  * @return 0 on success, <0 on failure.
1756  */
1757 static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
1758 {
1759 	struct dvb_device *dvbdev = file->private_data;
1760 	struct dvb_ca_private *ca = dvbdev->priv;
1761 	int err;
1762 
1763 	dprintk("%s\n", __func__);
1764 
1765 	/* mark the CA device as closed */
1766 	ca->open = 0;
1767 	dvb_ca_en50221_thread_update_delay(ca);
1768 
1769 	err = dvb_generic_release(inode, file);
1770 
1771 	module_put(ca->pub->owner);
1772 
1773 	dvb_ca_private_put(ca);
1774 
1775 	return err;
1776 }
1777 
1778 /**
1779  * Implementation of poll() syscall.
1780  *
1781  * @file: File concerned.
1782  * @wait: poll wait table.
1783  *
1784  * @return Standard poll mask.
1785  */
1786 static unsigned int dvb_ca_en50221_io_poll(struct file *file, poll_table *wait)
1787 {
1788 	struct dvb_device *dvbdev = file->private_data;
1789 	struct dvb_ca_private *ca = dvbdev->priv;
1790 	unsigned int mask = 0;
1791 	int slot;
1792 	int result = 0;
1793 
1794 	dprintk("%s\n", __func__);
1795 
1796 	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
1797 		mask |= POLLIN;
1798 
1799 	/* if there is something, return now */
1800 	if (mask)
1801 		return mask;
1802 
1803 	/* wait for something to happen */
1804 	poll_wait(file, &ca->wait_queue, wait);
1805 
1806 	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
1807 		mask |= POLLIN;
1808 
1809 	return mask;
1810 }
1811 
1812 static const struct file_operations dvb_ca_fops = {
1813 	.owner = THIS_MODULE,
1814 	.read = dvb_ca_en50221_io_read,
1815 	.write = dvb_ca_en50221_io_write,
1816 	.unlocked_ioctl = dvb_ca_en50221_io_ioctl,
1817 	.open = dvb_ca_en50221_io_open,
1818 	.release = dvb_ca_en50221_io_release,
1819 	.poll = dvb_ca_en50221_io_poll,
1820 	.llseek = noop_llseek,
1821 };
1822 
1823 static const struct dvb_device dvbdev_ca = {
1824 	.priv = NULL,
1825 	.users = 1,
1826 	.readers = 1,
1827 	.writers = 1,
1828 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
1829 	.name = "dvb-ca-en50221",
1830 #endif
1831 	.fops = &dvb_ca_fops,
1832 };
1833 
1834 /* ************************************************************************** */
1835 /* Initialisation/shutdown functions */
1836 
1837 /**
1838  * Initialise a new DVB CA EN50221 interface device.
1839  *
1840  * @dvb_adapter: DVB adapter to attach the new CA device to.
1841  * @ca: The dvb_ca instance.
1842  * @flags: Flags describing the CA device (DVB_CA_FLAG_*).
1843  * @slot_count: Number of slots supported.
1844  *
1845  * @return 0 on success, nonzero on failure
1846  */
1847 int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
1848 			struct dvb_ca_en50221 *pubca, int flags, int slot_count)
1849 {
1850 	int ret;
1851 	struct dvb_ca_private *ca = NULL;
1852 	int i;
1853 
1854 	dprintk("%s\n", __func__);
1855 
1856 	if (slot_count < 1)
1857 		return -EINVAL;
1858 
1859 	/* initialise the system data */
1860 	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1861 	if (!ca) {
1862 		ret = -ENOMEM;
1863 		goto exit;
1864 	}
1865 	kref_init(&ca->refcount);
1866 	ca->pub = pubca;
1867 	ca->flags = flags;
1868 	ca->slot_count = slot_count;
1869 	ca->slot_info = kcalloc(slot_count, sizeof(struct dvb_ca_slot),
1870 				GFP_KERNEL);
1871 	if (!ca->slot_info) {
1872 		ret = -ENOMEM;
1873 		goto free_ca;
1874 	}
1875 	init_waitqueue_head(&ca->wait_queue);
1876 	ca->open = 0;
1877 	ca->wakeup = 0;
1878 	ca->next_read_slot = 0;
1879 	pubca->private = ca;
1880 
1881 	/* register the DVB device */
1882 	ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca,
1883 				  DVB_DEVICE_CA, 0);
1884 	if (ret)
1885 		goto free_slot_info;
1886 
1887 	/* now initialise each slot */
1888 	for (i = 0; i < slot_count; i++) {
1889 		struct dvb_ca_slot *sl = &ca->slot_info[i];
1890 
1891 		memset(sl, 0, sizeof(struct dvb_ca_slot));
1892 		sl->slot_state = DVB_CA_SLOTSTATE_NONE;
1893 		atomic_set(&sl->camchange_count, 0);
1894 		sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
1895 		mutex_init(&sl->slot_lock);
1896 	}
1897 
1898 	mutex_init(&ca->ioctl_mutex);
1899 
1900 	if (signal_pending(current)) {
1901 		ret = -EINTR;
1902 		goto unregister_device;
1903 	}
1904 	mb();
1905 
1906 	/* create a kthread for monitoring this CA device */
1907 	ca->thread = kthread_run(dvb_ca_en50221_thread, ca, "kdvb-ca-%i:%i",
1908 				 ca->dvbdev->adapter->num, ca->dvbdev->id);
1909 	if (IS_ERR(ca->thread)) {
1910 		ret = PTR_ERR(ca->thread);
1911 		pr_err("dvb_ca_init: failed to start kernel_thread (%d)\n",
1912 		       ret);
1913 		goto unregister_device;
1914 	}
1915 	return 0;
1916 
1917 unregister_device:
1918 	dvb_unregister_device(ca->dvbdev);
1919 free_slot_info:
1920 	kfree(ca->slot_info);
1921 free_ca:
1922 	kfree(ca);
1923 exit:
1924 	pubca->private = NULL;
1925 	return ret;
1926 }
1927 EXPORT_SYMBOL(dvb_ca_en50221_init);
1928 
1929 /**
1930  * Release a DVB CA EN50221 interface device.
1931  *
1932  * @ca_dev: The dvb_device_t instance for the CA device.
1933  * @ca: The associated dvb_ca instance.
1934  */
1935 void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
1936 {
1937 	struct dvb_ca_private *ca = pubca->private;
1938 	int i;
1939 
1940 	dprintk("%s\n", __func__);
1941 
1942 	/* shutdown the thread if there was one */
1943 	kthread_stop(ca->thread);
1944 
1945 	for (i = 0; i < ca->slot_count; i++)
1946 		dvb_ca_en50221_slot_shutdown(ca, i);
1947 
1948 	dvb_remove_device(ca->dvbdev);
1949 	dvb_ca_private_put(ca);
1950 	pubca->private = NULL;
1951 }
1952 EXPORT_SYMBOL(dvb_ca_en50221_release);
1953