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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * dvb_ca.c: generic DVB functions for EN50221 CAM interfaces
4  *
5  * Copyright (C) 2004 Andrew de Quincey
6  *
7  * Parts of this file were based on sources as follows:
8  *
9  * Copyright (C) 2003 Ralph Metzler <rjkm@metzlerbros.de>
10  *
11  * based on code:
12  *
13  * Copyright (C) 1999-2002 Ralph  Metzler
14  *                       & Marcus Metzler for convergence integrated media GmbH
15  */
16 
17 #define pr_fmt(fmt) "dvb_ca_en50221: " fmt
18 
19 #include <linux/errno.h>
20 #include <linux/slab.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/nospec.h>
24 #include <linux/vmalloc.h>
25 #include <linux/delay.h>
26 #include <linux/spinlock.h>
27 #include <linux/sched/signal.h>
28 #include <linux/kthread.h>
29 
30 #include <media/dvb_ca_en50221.h>
31 #include <media/dvb_ringbuffer.h>
32 
33 static int dvb_ca_en50221_debug;
34 
35 module_param_named(cam_debug, dvb_ca_en50221_debug, int, 0644);
36 MODULE_PARM_DESC(cam_debug, "enable verbose debug messages");
37 
38 #define dprintk(fmt, arg...) do {					\
39 	if (dvb_ca_en50221_debug)					\
40 		printk(KERN_DEBUG pr_fmt("%s: " fmt), __func__, ##arg);\
41 } while (0)
42 
43 #define INIT_TIMEOUT_SECS 10
44 
45 #define HOST_LINK_BUF_SIZE 0x200
46 
47 #define RX_BUFFER_SIZE 65535
48 
49 #define MAX_RX_PACKETS_PER_ITERATION 10
50 
51 #define CTRLIF_DATA      0
52 #define CTRLIF_COMMAND   1
53 #define CTRLIF_STATUS    1
54 #define CTRLIF_SIZE_LOW  2
55 #define CTRLIF_SIZE_HIGH 3
56 
57 #define CMDREG_HC        1	/* Host control */
58 #define CMDREG_SW        2	/* Size write */
59 #define CMDREG_SR        4	/* Size read */
60 #define CMDREG_RS        8	/* Reset interface */
61 #define CMDREG_FRIE   0x40	/* Enable FR interrupt */
62 #define CMDREG_DAIE   0x80	/* Enable DA interrupt */
63 #define IRQEN (CMDREG_DAIE)
64 
65 #define STATUSREG_RE     1	/* read error */
66 #define STATUSREG_WE     2	/* write error */
67 #define STATUSREG_FR  0x40	/* module free */
68 #define STATUSREG_DA  0x80	/* data available */
69 
70 #define DVB_CA_SLOTSTATE_NONE           0
71 #define DVB_CA_SLOTSTATE_UNINITIALISED  1
72 #define DVB_CA_SLOTSTATE_RUNNING        2
73 #define DVB_CA_SLOTSTATE_INVALID        3
74 #define DVB_CA_SLOTSTATE_WAITREADY      4
75 #define DVB_CA_SLOTSTATE_VALIDATE       5
76 #define DVB_CA_SLOTSTATE_WAITFR         6
77 #define DVB_CA_SLOTSTATE_LINKINIT       7
78 
79 /* Information on a CA slot */
80 struct dvb_ca_slot {
81 	/* current state of the CAM */
82 	int slot_state;
83 
84 	/* mutex used for serializing access to one CI slot */
85 	struct mutex slot_lock;
86 
87 	/* Number of CAMCHANGES that have occurred since last processing */
88 	atomic_t camchange_count;
89 
90 	/* Type of last CAMCHANGE */
91 	int camchange_type;
92 
93 	/* base address of CAM config */
94 	u32 config_base;
95 
96 	/* value to write into Config Control register */
97 	u8 config_option;
98 
99 	/* if 1, the CAM supports DA IRQs */
100 	u8 da_irq_supported:1;
101 
102 	/* size of the buffer to use when talking to the CAM */
103 	int link_buf_size;
104 
105 	/* buffer for incoming packets */
106 	struct dvb_ringbuffer rx_buffer;
107 
108 	/* timer used during various states of the slot */
109 	unsigned long timeout;
110 };
111 
112 /* Private CA-interface information */
113 struct dvb_ca_private {
114 	struct kref refcount;
115 
116 	/* pointer back to the public data structure */
117 	struct dvb_ca_en50221 *pub;
118 
119 	/* the DVB device */
120 	struct dvb_device *dvbdev;
121 
122 	/* Flags describing the interface (DVB_CA_FLAG_*) */
123 	u32 flags;
124 
125 	/* number of slots supported by this CA interface */
126 	unsigned int slot_count;
127 
128 	/* information on each slot */
129 	struct dvb_ca_slot *slot_info;
130 
131 	/* wait queues for read() and write() operations */
132 	wait_queue_head_t wait_queue;
133 
134 	/* PID of the monitoring thread */
135 	struct task_struct *thread;
136 
137 	/* Flag indicating if the CA device is open */
138 	unsigned int open:1;
139 
140 	/* Flag indicating the thread should wake up now */
141 	unsigned int wakeup:1;
142 
143 	/* Delay the main thread should use */
144 	unsigned long delay;
145 
146 	/*
147 	 * Slot to start looking for data to read from in the next user-space
148 	 * read operation
149 	 */
150 	int next_read_slot;
151 
152 	/* mutex serializing ioctls */
153 	struct mutex ioctl_mutex;
154 
155 	/* A mutex used when a device is disconnected */
156 	struct mutex remove_mutex;
157 
158 	/* Whether the device is disconnected */
159 	int exit;
160 };
161 
dvb_ca_private_free(struct dvb_ca_private * ca)162 static void dvb_ca_private_free(struct dvb_ca_private *ca)
163 {
164 	unsigned int i;
165 
166 	dvb_device_put(ca->dvbdev);
167 	for (i = 0; i < ca->slot_count; i++)
168 		vfree(ca->slot_info[i].rx_buffer.data);
169 
170 	kfree(ca->slot_info);
171 	kfree(ca);
172 }
173 
dvb_ca_private_release(struct kref * ref)174 static void dvb_ca_private_release(struct kref *ref)
175 {
176 	struct dvb_ca_private *ca;
177 
178 	ca = container_of(ref, struct dvb_ca_private, refcount);
179 	dvb_ca_private_free(ca);
180 }
181 
dvb_ca_private_get(struct dvb_ca_private * ca)182 static void dvb_ca_private_get(struct dvb_ca_private *ca)
183 {
184 	kref_get(&ca->refcount);
185 }
186 
dvb_ca_private_put(struct dvb_ca_private * ca)187 static void dvb_ca_private_put(struct dvb_ca_private *ca)
188 {
189 	kref_put(&ca->refcount, dvb_ca_private_release);
190 }
191 
192 static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca);
193 static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
194 				    u8 *ebuf, int ecount);
195 static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
196 				     u8 *ebuf, int ecount, int size_write_flag);
197 
198 /**
199  * Safely find needle in haystack.
200  *
201  * @haystack: Buffer to look in.
202  * @hlen: Number of bytes in haystack.
203  * @needle: Buffer to find.
204  * @nlen: Number of bytes in needle.
205  * return: Pointer into haystack needle was found at, or NULL if not found.
206  */
findstr(char * haystack,int hlen,char * needle,int nlen)207 static char *findstr(char *haystack, int hlen, char *needle, int nlen)
208 {
209 	int i;
210 
211 	if (hlen < nlen)
212 		return NULL;
213 
214 	for (i = 0; i <= hlen - nlen; i++) {
215 		if (!strncmp(haystack + i, needle, nlen))
216 			return haystack + i;
217 	}
218 
219 	return NULL;
220 }
221 
222 /* ************************************************************************** */
223 /* EN50221 physical interface functions */
224 
225 /*
226  * dvb_ca_en50221_check_camstatus - Check CAM status.
227  */
dvb_ca_en50221_check_camstatus(struct dvb_ca_private * ca,int slot)228 static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private *ca, int slot)
229 {
230 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
231 	int slot_status;
232 	int cam_present_now;
233 	int cam_changed;
234 
235 	/* IRQ mode */
236 	if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
237 		return (atomic_read(&sl->camchange_count) != 0);
238 
239 	/* poll mode */
240 	slot_status = ca->pub->poll_slot_status(ca->pub, slot, ca->open);
241 
242 	cam_present_now = (slot_status & DVB_CA_EN50221_POLL_CAM_PRESENT) ? 1 : 0;
243 	cam_changed = (slot_status & DVB_CA_EN50221_POLL_CAM_CHANGED) ? 1 : 0;
244 	if (!cam_changed) {
245 		int cam_present_old = (sl->slot_state != DVB_CA_SLOTSTATE_NONE);
246 
247 		cam_changed = (cam_present_now != cam_present_old);
248 	}
249 
250 	if (cam_changed) {
251 		if (!cam_present_now)
252 			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
253 		else
254 			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
255 		atomic_set(&sl->camchange_count, 1);
256 	} else {
257 		if ((sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
258 		    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
259 			/* move to validate state if reset is completed */
260 			sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
261 		}
262 	}
263 
264 	return cam_changed;
265 }
266 
267 /**
268  * dvb_ca_en50221_wait_if_status - Wait for flags to become set on the STATUS
269  *	 register on a CAM interface, checking for errors and timeout.
270  *
271  * @ca: CA instance.
272  * @slot: Slot on interface.
273  * @waitfor: Flags to wait for.
274  * @timeout_hz: Timeout in milliseconds.
275  *
276  * return: 0 on success, nonzero on error.
277  */
dvb_ca_en50221_wait_if_status(struct dvb_ca_private * ca,int slot,u8 waitfor,int timeout_hz)278 static int dvb_ca_en50221_wait_if_status(struct dvb_ca_private *ca, int slot,
279 					 u8 waitfor, int timeout_hz)
280 {
281 	unsigned long timeout;
282 	unsigned long start;
283 
284 	dprintk("%s\n", __func__);
285 
286 	/* loop until timeout elapsed */
287 	start = jiffies;
288 	timeout = jiffies + timeout_hz;
289 	while (1) {
290 		int res;
291 
292 		/* read the status and check for error */
293 		res = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
294 		if (res < 0)
295 			return -EIO;
296 
297 		/* if we got the flags, it was successful! */
298 		if (res & waitfor) {
299 			dprintk("%s succeeded timeout:%lu\n",
300 				__func__, jiffies - start);
301 			return 0;
302 		}
303 
304 		/* check for timeout */
305 		if (time_after(jiffies, timeout))
306 			break;
307 
308 		/* wait for a bit */
309 		usleep_range(1000, 1100);
310 	}
311 
312 	dprintk("%s failed timeout:%lu\n", __func__, jiffies - start);
313 
314 	/* if we get here, we've timed out */
315 	return -ETIMEDOUT;
316 }
317 
318 /**
319  * dvb_ca_en50221_link_init - Initialise the link layer connection to a CAM.
320  *
321  * @ca: CA instance.
322  * @slot: Slot id.
323  *
324  * return: 0 on success, nonzero on failure.
325  */
dvb_ca_en50221_link_init(struct dvb_ca_private * ca,int slot)326 static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot)
327 {
328 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
329 	int ret;
330 	int buf_size;
331 	u8 buf[2];
332 
333 	dprintk("%s\n", __func__);
334 
335 	/* we'll be determining these during this function */
336 	sl->da_irq_supported = 0;
337 
338 	/*
339 	 * set the host link buffer size temporarily. it will be overwritten
340 	 * with the real negotiated size later.
341 	 */
342 	sl->link_buf_size = 2;
343 
344 	/* read the buffer size from the CAM */
345 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
346 					 IRQEN | CMDREG_SR);
347 	if (ret)
348 		return ret;
349 	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ);
350 	if (ret)
351 		return ret;
352 	ret = dvb_ca_en50221_read_data(ca, slot, buf, 2);
353 	if (ret != 2)
354 		return -EIO;
355 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
356 	if (ret)
357 		return ret;
358 
359 	/*
360 	 * store it, and choose the minimum of our buffer and the CAM's buffer
361 	 * size
362 	 */
363 	buf_size = (buf[0] << 8) | buf[1];
364 	if (buf_size > HOST_LINK_BUF_SIZE)
365 		buf_size = HOST_LINK_BUF_SIZE;
366 	sl->link_buf_size = buf_size;
367 	buf[0] = buf_size >> 8;
368 	buf[1] = buf_size & 0xff;
369 	dprintk("Chosen link buffer size of %i\n", buf_size);
370 
371 	/* write the buffer size to the CAM */
372 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
373 					 IRQEN | CMDREG_SW);
374 	if (ret)
375 		return ret;
376 	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10);
377 	if (ret)
378 		return ret;
379 	ret = dvb_ca_en50221_write_data(ca, slot, buf, 2, CMDREG_SW);
380 	if (ret != 2)
381 		return -EIO;
382 	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
383 	if (ret)
384 		return ret;
385 
386 	/* success */
387 	return 0;
388 }
389 
390 /**
391  * dvb_ca_en50221_read_tuple - Read a tuple from attribute memory.
392  *
393  * @ca: CA instance.
394  * @slot: Slot id.
395  * @address: Address to read from. Updated.
396  * @tuple_type: Tuple id byte. Updated.
397  * @tuple_length: Tuple length. Updated.
398  * @tuple: Dest buffer for tuple (must be 256 bytes). Updated.
399  *
400  * return: 0 on success, nonzero on error.
401  */
dvb_ca_en50221_read_tuple(struct dvb_ca_private * ca,int slot,int * address,int * tuple_type,int * tuple_length,u8 * tuple)402 static int dvb_ca_en50221_read_tuple(struct dvb_ca_private *ca, int slot,
403 				     int *address, int *tuple_type,
404 				     int *tuple_length, u8 *tuple)
405 {
406 	int i;
407 	int _tuple_type;
408 	int _tuple_length;
409 	int _address = *address;
410 
411 	/* grab the next tuple length and type */
412 	_tuple_type = ca->pub->read_attribute_mem(ca->pub, slot, _address);
413 	if (_tuple_type < 0)
414 		return _tuple_type;
415 	if (_tuple_type == 0xff) {
416 		dprintk("END OF CHAIN TUPLE type:0x%x\n", _tuple_type);
417 		*address += 2;
418 		*tuple_type = _tuple_type;
419 		*tuple_length = 0;
420 		return 0;
421 	}
422 	_tuple_length = ca->pub->read_attribute_mem(ca->pub, slot,
423 						    _address + 2);
424 	if (_tuple_length < 0)
425 		return _tuple_length;
426 	_address += 4;
427 
428 	dprintk("TUPLE type:0x%x length:%i\n", _tuple_type, _tuple_length);
429 
430 	/* read in the whole tuple */
431 	for (i = 0; i < _tuple_length; i++) {
432 		tuple[i] = ca->pub->read_attribute_mem(ca->pub, slot,
433 						       _address + (i * 2));
434 		dprintk("  0x%02x: 0x%02x %c\n",
435 			i, tuple[i] & 0xff,
436 			((tuple[i] > 31) && (tuple[i] < 127)) ? tuple[i] : '.');
437 	}
438 	_address += (_tuple_length * 2);
439 
440 	/* success */
441 	*tuple_type = _tuple_type;
442 	*tuple_length = _tuple_length;
443 	*address = _address;
444 	return 0;
445 }
446 
447 /**
448  * dvb_ca_en50221_parse_attributes - Parse attribute memory of a CAM module,
449  *	extracting Config register, and checking it is a DVB CAM module.
450  *
451  * @ca: CA instance.
452  * @slot: Slot id.
453  *
454  * return: 0 on success, <0 on failure.
455  */
dvb_ca_en50221_parse_attributes(struct dvb_ca_private * ca,int slot)456 static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private *ca, int slot)
457 {
458 	struct dvb_ca_slot *sl;
459 	int address = 0;
460 	int tuple_length;
461 	int tuple_type;
462 	u8 tuple[257];
463 	char *dvb_str;
464 	int rasz;
465 	int status;
466 	int got_cftableentry = 0;
467 	int end_chain = 0;
468 	int i;
469 	u16 manfid = 0;
470 	u16 devid = 0;
471 
472 	/* CISTPL_DEVICE_0A */
473 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
474 					   &tuple_length, tuple);
475 	if (status < 0)
476 		return status;
477 	if (tuple_type != 0x1D)
478 		return -EINVAL;
479 
480 	/* CISTPL_DEVICE_0C */
481 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
482 					   &tuple_length, tuple);
483 	if (status < 0)
484 		return status;
485 	if (tuple_type != 0x1C)
486 		return -EINVAL;
487 
488 	/* CISTPL_VERS_1 */
489 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
490 					   &tuple_length, tuple);
491 	if (status < 0)
492 		return status;
493 	if (tuple_type != 0x15)
494 		return -EINVAL;
495 
496 	/* CISTPL_MANFID */
497 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
498 					   &tuple_length, tuple);
499 	if (status < 0)
500 		return status;
501 	if (tuple_type != 0x20)
502 		return -EINVAL;
503 	if (tuple_length != 4)
504 		return -EINVAL;
505 	manfid = (tuple[1] << 8) | tuple[0];
506 	devid = (tuple[3] << 8) | tuple[2];
507 
508 	/* CISTPL_CONFIG */
509 	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
510 					   &tuple_length, tuple);
511 	if (status < 0)
512 		return status;
513 	if (tuple_type != 0x1A)
514 		return -EINVAL;
515 	if (tuple_length < 3)
516 		return -EINVAL;
517 
518 	/* extract the configbase */
519 	rasz = tuple[0] & 3;
520 	if (tuple_length < (3 + rasz + 14))
521 		return -EINVAL;
522 	sl = &ca->slot_info[slot];
523 	sl->config_base = 0;
524 	for (i = 0; i < rasz + 1; i++)
525 		sl->config_base |= (tuple[2 + i] << (8 * i));
526 
527 	/* check it contains the correct DVB string */
528 	dvb_str = findstr((char *)tuple, tuple_length, "DVB_CI_V", 8);
529 	if (!dvb_str)
530 		return -EINVAL;
531 	if (tuple_length < ((dvb_str - (char *)tuple) + 12))
532 		return -EINVAL;
533 
534 	/* is it a version we support? */
535 	if (strncmp(dvb_str + 8, "1.00", 4)) {
536 		pr_err("dvb_ca adapter %d: Unsupported DVB CAM module version %c%c%c%c\n",
537 		       ca->dvbdev->adapter->num, dvb_str[8], dvb_str[9],
538 		       dvb_str[10], dvb_str[11]);
539 		return -EINVAL;
540 	}
541 
542 	/* process the CFTABLE_ENTRY tuples, and any after those */
543 	while ((!end_chain) && (address < 0x1000)) {
544 		status = dvb_ca_en50221_read_tuple(ca, slot, &address,
545 						   &tuple_type, &tuple_length,
546 						   tuple);
547 		if (status < 0)
548 			return status;
549 		switch (tuple_type) {
550 		case 0x1B:	/* CISTPL_CFTABLE_ENTRY */
551 			if (tuple_length < (2 + 11 + 17))
552 				break;
553 
554 			/* if we've already parsed one, just use it */
555 			if (got_cftableentry)
556 				break;
557 
558 			/* get the config option */
559 			sl->config_option = tuple[0] & 0x3f;
560 
561 			/* OK, check it contains the correct strings */
562 			if (!findstr((char *)tuple, tuple_length,
563 				     "DVB_HOST", 8) ||
564 			    !findstr((char *)tuple, tuple_length,
565 				     "DVB_CI_MODULE", 13))
566 				break;
567 
568 			got_cftableentry = 1;
569 			break;
570 
571 		case 0x14:	/* CISTPL_NO_LINK */
572 			break;
573 
574 		case 0xFF:	/* CISTPL_END */
575 			end_chain = 1;
576 			break;
577 
578 		default:	/* Unknown tuple type - just skip this tuple */
579 			dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n",
580 				tuple_type, tuple_length);
581 			break;
582 		}
583 	}
584 
585 	if ((address > 0x1000) || (!got_cftableentry))
586 		return -EINVAL;
587 
588 	dprintk("Valid DVB CAM detected MANID:%x DEVID:%x CONFIGBASE:0x%x CONFIGOPTION:0x%x\n",
589 		manfid, devid, sl->config_base, sl->config_option);
590 
591 	/* success! */
592 	return 0;
593 }
594 
595 /**
596  * dvb_ca_en50221_set_configoption - Set CAM's configoption correctly.
597  *
598  * @ca: CA instance.
599  * @slot: Slot containing the CAM.
600  */
dvb_ca_en50221_set_configoption(struct dvb_ca_private * ca,int slot)601 static int dvb_ca_en50221_set_configoption(struct dvb_ca_private *ca, int slot)
602 {
603 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
604 	int configoption;
605 
606 	dprintk("%s\n", __func__);
607 
608 	/* set the config option */
609 	ca->pub->write_attribute_mem(ca->pub, slot, sl->config_base,
610 				     sl->config_option);
611 
612 	/* check it */
613 	configoption = ca->pub->read_attribute_mem(ca->pub, slot,
614 						   sl->config_base);
615 	dprintk("Set configoption 0x%x, read configoption 0x%x\n",
616 		sl->config_option, configoption & 0x3f);
617 
618 	/* fine! */
619 	return 0;
620 }
621 
622 /**
623  * dvb_ca_en50221_read_data - This function talks to an EN50221 CAM control
624  *	interface. It reads a buffer of data from the CAM. The data can either
625  *	be stored in a supplied buffer, or automatically be added to the slot's
626  *	rx_buffer.
627  *
628  * @ca: CA instance.
629  * @slot: Slot to read from.
630  * @ebuf: If non-NULL, the data will be written to this buffer. If NULL,
631  *	  the data will be added into the buffering system as a normal
632  *	  fragment.
633  * @ecount: Size of ebuf. Ignored if ebuf is NULL.
634  *
635  * return: Number of bytes read, or < 0 on error
636  */
dvb_ca_en50221_read_data(struct dvb_ca_private * ca,int slot,u8 * ebuf,int ecount)637 static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
638 				    u8 *ebuf, int ecount)
639 {
640 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
641 	int bytes_read;
642 	int status;
643 	u8 buf[HOST_LINK_BUF_SIZE];
644 	int i;
645 
646 	dprintk("%s\n", __func__);
647 
648 	/* check if we have space for a link buf in the rx_buffer */
649 	if (!ebuf) {
650 		int buf_free;
651 
652 		if (!sl->rx_buffer.data) {
653 			status = -EIO;
654 			goto exit;
655 		}
656 		buf_free = dvb_ringbuffer_free(&sl->rx_buffer);
657 
658 		if (buf_free < (sl->link_buf_size +
659 				DVB_RINGBUFFER_PKTHDRSIZE)) {
660 			status = -EAGAIN;
661 			goto exit;
662 		}
663 	}
664 
665 	if (ca->pub->read_data &&
666 	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT)) {
667 		if (!ebuf)
668 			status = ca->pub->read_data(ca->pub, slot, buf,
669 						    sizeof(buf));
670 		else
671 			status = ca->pub->read_data(ca->pub, slot, buf, ecount);
672 		if (status < 0)
673 			return status;
674 		bytes_read =  status;
675 		if (status == 0)
676 			goto exit;
677 	} else {
678 		/* check if there is data available */
679 		status = ca->pub->read_cam_control(ca->pub, slot,
680 						   CTRLIF_STATUS);
681 		if (status < 0)
682 			goto exit;
683 		if (!(status & STATUSREG_DA)) {
684 			/* no data */
685 			status = 0;
686 			goto exit;
687 		}
688 
689 		/* read the amount of data */
690 		status = ca->pub->read_cam_control(ca->pub, slot,
691 						   CTRLIF_SIZE_HIGH);
692 		if (status < 0)
693 			goto exit;
694 		bytes_read = status << 8;
695 		status = ca->pub->read_cam_control(ca->pub, slot,
696 						   CTRLIF_SIZE_LOW);
697 		if (status < 0)
698 			goto exit;
699 		bytes_read |= status;
700 
701 		/* check it will fit */
702 		if (!ebuf) {
703 			if (bytes_read > sl->link_buf_size) {
704 				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the link buffer size (%i > %i)!\n",
705 				       ca->dvbdev->adapter->num, bytes_read,
706 				       sl->link_buf_size);
707 				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
708 				status = -EIO;
709 				goto exit;
710 			}
711 			if (bytes_read < 2) {
712 				pr_err("dvb_ca adapter %d: CAM sent a buffer that was less than 2 bytes!\n",
713 				       ca->dvbdev->adapter->num);
714 				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
715 				status = -EIO;
716 				goto exit;
717 			}
718 		} else {
719 			if (bytes_read > ecount) {
720 				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the ecount size!\n",
721 				       ca->dvbdev->adapter->num);
722 				status = -EIO;
723 				goto exit;
724 			}
725 		}
726 
727 		/* fill the buffer */
728 		for (i = 0; i < bytes_read; i++) {
729 			/* read byte and check */
730 			status = ca->pub->read_cam_control(ca->pub, slot,
731 							   CTRLIF_DATA);
732 			if (status < 0)
733 				goto exit;
734 
735 			/* OK, store it in the buffer */
736 			buf[i] = status;
737 		}
738 
739 		/* check for read error (RE should now be 0) */
740 		status = ca->pub->read_cam_control(ca->pub, slot,
741 						   CTRLIF_STATUS);
742 		if (status < 0)
743 			goto exit;
744 		if (status & STATUSREG_RE) {
745 			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
746 			status = -EIO;
747 			goto exit;
748 		}
749 	}
750 
751 	/*
752 	 * OK, add it to the receive buffer, or copy into external buffer if
753 	 * supplied
754 	 */
755 	if (!ebuf) {
756 		if (!sl->rx_buffer.data) {
757 			status = -EIO;
758 			goto exit;
759 		}
760 		dvb_ringbuffer_pkt_write(&sl->rx_buffer, buf, bytes_read);
761 	} else {
762 		memcpy(ebuf, buf, bytes_read);
763 	}
764 
765 	dprintk("Received CA packet for slot %i connection id 0x%x last_frag:%i size:0x%x\n", slot,
766 		buf[0], (buf[1] & 0x80) == 0, bytes_read);
767 
768 	/* wake up readers when a last_fragment is received */
769 	if ((buf[1] & 0x80) == 0x00)
770 		wake_up_interruptible(&ca->wait_queue);
771 
772 	status = bytes_read;
773 
774 exit:
775 	return status;
776 }
777 
778 /**
779  * dvb_ca_en50221_write_data - This function talks to an EN50221 CAM control
780  *				interface. It writes a buffer of data to a CAM.
781  *
782  * @ca: CA instance.
783  * @slot: Slot to write to.
784  * @buf: The data in this buffer is treated as a complete link-level packet to
785  *	 be written.
786  * @bytes_write: Size of ebuf.
787  * @size_write_flag: A flag on Command Register which says whether the link size
788  * information will be writen or not.
789  *
790  * return: Number of bytes written, or < 0 on error.
791  */
dvb_ca_en50221_write_data(struct dvb_ca_private * ca,int slot,u8 * buf,int bytes_write,int size_write_flag)792 static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
793 				     u8 *buf, int bytes_write, int size_write_flag)
794 {
795 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
796 	int status;
797 	int i;
798 
799 	dprintk("%s\n", __func__);
800 
801 	/* sanity check */
802 	if (bytes_write > sl->link_buf_size)
803 		return -EINVAL;
804 
805 	if (ca->pub->write_data &&
806 	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT))
807 		return ca->pub->write_data(ca->pub, slot, buf, bytes_write);
808 
809 	/*
810 	 * it is possible we are dealing with a single buffer implementation,
811 	 * thus if there is data available for read or if there is even a read
812 	 * already in progress, we do nothing but awake the kernel thread to
813 	 * process the data if necessary.
814 	 */
815 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
816 	if (status < 0)
817 		goto exitnowrite;
818 	if (status & (STATUSREG_DA | STATUSREG_RE)) {
819 		if (status & STATUSREG_DA)
820 			dvb_ca_en50221_thread_wakeup(ca);
821 
822 		status = -EAGAIN;
823 		goto exitnowrite;
824 	}
825 
826 	/* OK, set HC bit */
827 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
828 					    IRQEN | CMDREG_HC | size_write_flag);
829 	if (status)
830 		goto exit;
831 
832 	/* check if interface is still free */
833 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
834 	if (status < 0)
835 		goto exit;
836 	if (!(status & STATUSREG_FR)) {
837 		/* it wasn't free => try again later */
838 		status = -EAGAIN;
839 		goto exit;
840 	}
841 
842 	/*
843 	 * It may need some time for the CAM to settle down, or there might
844 	 * be a race condition between the CAM, writing HC and our last
845 	 * check for DA. This happens, if the CAM asserts DA, just after
846 	 * checking DA before we are setting HC. In this case it might be
847 	 * a bug in the CAM to keep the FR bit, the lower layer/HW
848 	 * communication requires a longer timeout or the CAM needs more
849 	 * time internally. But this happens in reality!
850 	 * We need to read the status from the HW again and do the same
851 	 * we did for the previous check for DA
852 	 */
853 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
854 	if (status < 0)
855 		goto exit;
856 
857 	if (status & (STATUSREG_DA | STATUSREG_RE)) {
858 		if (status & STATUSREG_DA)
859 			dvb_ca_en50221_thread_wakeup(ca);
860 
861 		status = -EAGAIN;
862 		goto exit;
863 	}
864 
865 	/* send the amount of data */
866 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH,
867 					    bytes_write >> 8);
868 	if (status)
869 		goto exit;
870 	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW,
871 					    bytes_write & 0xff);
872 	if (status)
873 		goto exit;
874 
875 	/* send the buffer */
876 	for (i = 0; i < bytes_write; i++) {
877 		status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA,
878 						    buf[i]);
879 		if (status)
880 			goto exit;
881 	}
882 
883 	/* check for write error (WE should now be 0) */
884 	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
885 	if (status < 0)
886 		goto exit;
887 	if (status & STATUSREG_WE) {
888 		sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
889 		status = -EIO;
890 		goto exit;
891 	}
892 	status = bytes_write;
893 
894 	dprintk("Wrote CA packet for slot %i, connection id 0x%x last_frag:%i size:0x%x\n", slot,
895 		buf[0], (buf[1] & 0x80) == 0, bytes_write);
896 
897 exit:
898 	ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
899 
900 exitnowrite:
901 	return status;
902 }
903 
904 /* ************************************************************************** */
905 /* EN50221 higher level functions */
906 
907 /**
908  * dvb_ca_en50221_slot_shutdown - A CAM has been removed => shut it down.
909  *
910  * @ca: CA instance.
911  * @slot: Slot to shut down.
912  */
dvb_ca_en50221_slot_shutdown(struct dvb_ca_private * ca,int slot)913 static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private *ca, int slot)
914 {
915 	dprintk("%s\n", __func__);
916 
917 	ca->pub->slot_shutdown(ca->pub, slot);
918 	ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
919 
920 	/*
921 	 * need to wake up all processes to check if they're now trying to
922 	 * write to a defunct CAM
923 	 */
924 	wake_up_interruptible(&ca->wait_queue);
925 
926 	dprintk("Slot %i shutdown\n", slot);
927 
928 	/* success */
929 	return 0;
930 }
931 
932 /**
933  * dvb_ca_en50221_camchange_irq - A CAMCHANGE IRQ has occurred.
934  *
935  * @pubca: CA instance.
936  * @slot: Slot concerned.
937  * @change_type: One of the DVB_CA_CAMCHANGE_* values.
938  */
dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221 * pubca,int slot,int change_type)939 void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221 *pubca, int slot,
940 				  int change_type)
941 {
942 	struct dvb_ca_private *ca = pubca->private;
943 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
944 
945 	dprintk("CAMCHANGE IRQ slot:%i change_type:%i\n", slot, change_type);
946 
947 	switch (change_type) {
948 	case DVB_CA_EN50221_CAMCHANGE_REMOVED:
949 	case DVB_CA_EN50221_CAMCHANGE_INSERTED:
950 		break;
951 
952 	default:
953 		return;
954 	}
955 
956 	sl->camchange_type = change_type;
957 	atomic_inc(&sl->camchange_count);
958 	dvb_ca_en50221_thread_wakeup(ca);
959 }
960 EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);
961 
962 /**
963  * dvb_ca_en50221_camready_irq - A CAMREADY IRQ has occurred.
964  *
965  * @pubca: CA instance.
966  * @slot: Slot concerned.
967  */
dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 * pubca,int slot)968 void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 *pubca, int slot)
969 {
970 	struct dvb_ca_private *ca = pubca->private;
971 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
972 
973 	dprintk("CAMREADY IRQ slot:%i\n", slot);
974 
975 	if (sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
976 		sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
977 		dvb_ca_en50221_thread_wakeup(ca);
978 	}
979 }
980 EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);
981 
982 /**
983  * dvb_ca_en50221_frda_irq - An FR or DA IRQ has occurred.
984  *
985  * @pubca: CA instance.
986  * @slot: Slot concerned.
987  */
dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 * pubca,int slot)988 void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
989 {
990 	struct dvb_ca_private *ca = pubca->private;
991 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
992 	int flags;
993 
994 	dprintk("FR/DA IRQ slot:%i\n", slot);
995 
996 	switch (sl->slot_state) {
997 	case DVB_CA_SLOTSTATE_LINKINIT:
998 		flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
999 		if (flags & STATUSREG_DA) {
1000 			dprintk("CAM supports DA IRQ\n");
1001 			sl->da_irq_supported = 1;
1002 		}
1003 		break;
1004 
1005 	case DVB_CA_SLOTSTATE_RUNNING:
1006 		if (ca->open)
1007 			dvb_ca_en50221_thread_wakeup(ca);
1008 		break;
1009 	}
1010 }
1011 EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);
1012 
1013 /* ************************************************************************** */
1014 /* EN50221 thread functions */
1015 
1016 /**
1017  * Wake up the DVB CA thread
1018  *
1019  * @ca: CA instance.
1020  */
dvb_ca_en50221_thread_wakeup(struct dvb_ca_private * ca)1021 static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca)
1022 {
1023 	dprintk("%s\n", __func__);
1024 
1025 	ca->wakeup = 1;
1026 	mb();
1027 	wake_up_process(ca->thread);
1028 }
1029 
1030 /**
1031  * Update the delay used by the thread.
1032  *
1033  * @ca: CA instance.
1034  */
dvb_ca_en50221_thread_update_delay(struct dvb_ca_private * ca)1035 static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private *ca)
1036 {
1037 	int delay;
1038 	int curdelay = 100000000;
1039 	int slot;
1040 
1041 	/*
1042 	 * Beware of too high polling frequency, because one polling
1043 	 * call might take several hundred milliseconds until timeout!
1044 	 */
1045 	for (slot = 0; slot < ca->slot_count; slot++) {
1046 		struct dvb_ca_slot *sl = &ca->slot_info[slot];
1047 
1048 		switch (sl->slot_state) {
1049 		default:
1050 		case DVB_CA_SLOTSTATE_NONE:
1051 			delay = HZ * 60;  /* 60s */
1052 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1053 				delay = HZ * 5;  /* 5s */
1054 			break;
1055 		case DVB_CA_SLOTSTATE_INVALID:
1056 			delay = HZ * 60;  /* 60s */
1057 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1058 				delay = HZ / 10;  /* 100ms */
1059 			break;
1060 
1061 		case DVB_CA_SLOTSTATE_UNINITIALISED:
1062 		case DVB_CA_SLOTSTATE_WAITREADY:
1063 		case DVB_CA_SLOTSTATE_VALIDATE:
1064 		case DVB_CA_SLOTSTATE_WAITFR:
1065 		case DVB_CA_SLOTSTATE_LINKINIT:
1066 			delay = HZ / 10;  /* 100ms */
1067 			break;
1068 
1069 		case DVB_CA_SLOTSTATE_RUNNING:
1070 			delay = HZ * 60;  /* 60s */
1071 			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
1072 				delay = HZ / 10;  /* 100ms */
1073 			if (ca->open) {
1074 				if ((!sl->da_irq_supported) ||
1075 				    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA)))
1076 					delay = HZ / 10;  /* 100ms */
1077 			}
1078 			break;
1079 		}
1080 
1081 		if (delay < curdelay)
1082 			curdelay = delay;
1083 	}
1084 
1085 	ca->delay = curdelay;
1086 }
1087 
1088 /**
1089  * Poll if the CAM is gone.
1090  *
1091  * @ca: CA instance.
1092  * @slot: Slot to process.
1093  * return:: 0 .. no change
1094  *          1 .. CAM state changed
1095  */
1096 
dvb_ca_en50221_poll_cam_gone(struct dvb_ca_private * ca,int slot)1097 static int dvb_ca_en50221_poll_cam_gone(struct dvb_ca_private *ca, int slot)
1098 {
1099 	int changed = 0;
1100 	int status;
1101 
1102 	/*
1103 	 * we need this extra check for annoying interfaces like the
1104 	 * budget-av
1105 	 */
1106 	if ((!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) &&
1107 	    (ca->pub->poll_slot_status)) {
1108 		status = ca->pub->poll_slot_status(ca->pub, slot, 0);
1109 		if (!(status &
1110 			DVB_CA_EN50221_POLL_CAM_PRESENT)) {
1111 			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
1112 			dvb_ca_en50221_thread_update_delay(ca);
1113 			changed = 1;
1114 		}
1115 	}
1116 	return changed;
1117 }
1118 
1119 /**
1120  * Thread state machine for one CA slot to perform the data transfer.
1121  *
1122  * @ca: CA instance.
1123  * @slot: Slot to process.
1124  */
dvb_ca_en50221_thread_state_machine(struct dvb_ca_private * ca,int slot)1125 static void dvb_ca_en50221_thread_state_machine(struct dvb_ca_private *ca,
1126 						int slot)
1127 {
1128 	struct dvb_ca_slot *sl = &ca->slot_info[slot];
1129 	int flags;
1130 	int pktcount;
1131 	void *rxbuf;
1132 
1133 	mutex_lock(&sl->slot_lock);
1134 
1135 	/* check the cam status + deal with CAMCHANGEs */
1136 	while (dvb_ca_en50221_check_camstatus(ca, slot)) {
1137 		/* clear down an old CI slot if necessary */
1138 		if (sl->slot_state != DVB_CA_SLOTSTATE_NONE)
1139 			dvb_ca_en50221_slot_shutdown(ca, slot);
1140 
1141 		/* if a CAM is NOW present, initialise it */
1142 		if (sl->camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED)
1143 			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
1144 
1145 		/* we've handled one CAMCHANGE */
1146 		dvb_ca_en50221_thread_update_delay(ca);
1147 		atomic_dec(&sl->camchange_count);
1148 	}
1149 
1150 	/* CAM state machine */
1151 	switch (sl->slot_state) {
1152 	case DVB_CA_SLOTSTATE_NONE:
1153 	case DVB_CA_SLOTSTATE_INVALID:
1154 		/* no action needed */
1155 		break;
1156 
1157 	case DVB_CA_SLOTSTATE_UNINITIALISED:
1158 		sl->slot_state = DVB_CA_SLOTSTATE_WAITREADY;
1159 		ca->pub->slot_reset(ca->pub, slot);
1160 		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
1161 		break;
1162 
1163 	case DVB_CA_SLOTSTATE_WAITREADY:
1164 		if (time_after(jiffies, sl->timeout)) {
1165 			pr_err("dvb_ca adaptor %d: PC card did not respond :(\n",
1166 			       ca->dvbdev->adapter->num);
1167 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1168 			dvb_ca_en50221_thread_update_delay(ca);
1169 			break;
1170 		}
1171 		/*
1172 		 * no other action needed; will automatically change state when
1173 		 * ready
1174 		 */
1175 		break;
1176 
1177 	case DVB_CA_SLOTSTATE_VALIDATE:
1178 		if (dvb_ca_en50221_parse_attributes(ca, slot) != 0) {
1179 			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
1180 				break;
1181 
1182 			pr_err("dvb_ca adapter %d: Invalid PC card inserted :(\n",
1183 			       ca->dvbdev->adapter->num);
1184 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1185 			dvb_ca_en50221_thread_update_delay(ca);
1186 			break;
1187 		}
1188 		if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
1189 			pr_err("dvb_ca adapter %d: Unable to initialise CAM :(\n",
1190 			       ca->dvbdev->adapter->num);
1191 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1192 			dvb_ca_en50221_thread_update_delay(ca);
1193 			break;
1194 		}
1195 		if (ca->pub->write_cam_control(ca->pub, slot,
1196 					       CTRLIF_COMMAND,
1197 					       CMDREG_RS) != 0) {
1198 			pr_err("dvb_ca adapter %d: Unable to reset CAM IF\n",
1199 			       ca->dvbdev->adapter->num);
1200 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1201 			dvb_ca_en50221_thread_update_delay(ca);
1202 			break;
1203 		}
1204 		dprintk("DVB CAM validated successfully\n");
1205 
1206 		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
1207 		sl->slot_state = DVB_CA_SLOTSTATE_WAITFR;
1208 		ca->wakeup = 1;
1209 		break;
1210 
1211 	case DVB_CA_SLOTSTATE_WAITFR:
1212 		if (time_after(jiffies, sl->timeout)) {
1213 			pr_err("dvb_ca adapter %d: DVB CAM did not respond :(\n",
1214 			       ca->dvbdev->adapter->num);
1215 			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1216 			dvb_ca_en50221_thread_update_delay(ca);
1217 			break;
1218 		}
1219 
1220 		flags = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
1221 		if (flags & STATUSREG_FR) {
1222 			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
1223 			ca->wakeup = 1;
1224 		}
1225 		break;
1226 
1227 	case DVB_CA_SLOTSTATE_LINKINIT:
1228 		if (dvb_ca_en50221_link_init(ca, slot) != 0) {
1229 			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
1230 				break;
1231 
1232 			pr_err("dvb_ca adapter %d: DVB CAM link initialisation failed :(\n",
1233 			       ca->dvbdev->adapter->num);
1234 			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
1235 			dvb_ca_en50221_thread_update_delay(ca);
1236 			break;
1237 		}
1238 
1239 		if (!sl->rx_buffer.data) {
1240 			rxbuf = vmalloc(RX_BUFFER_SIZE);
1241 			if (!rxbuf) {
1242 				pr_err("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n",
1243 				       ca->dvbdev->adapter->num);
1244 				sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
1245 				dvb_ca_en50221_thread_update_delay(ca);
1246 				break;
1247 			}
1248 			dvb_ringbuffer_init(&sl->rx_buffer, rxbuf,
1249 					    RX_BUFFER_SIZE);
1250 		}
1251 
1252 		ca->pub->slot_ts_enable(ca->pub, slot);
1253 		sl->slot_state = DVB_CA_SLOTSTATE_RUNNING;
1254 		dvb_ca_en50221_thread_update_delay(ca);
1255 		pr_info("dvb_ca adapter %d: DVB CAM detected and initialised successfully\n",
1256 			ca->dvbdev->adapter->num);
1257 		break;
1258 
1259 	case DVB_CA_SLOTSTATE_RUNNING:
1260 		if (!ca->open)
1261 			break;
1262 
1263 		/* poll slots for data */
1264 		pktcount = 0;
1265 		while (dvb_ca_en50221_read_data(ca, slot, NULL, 0) > 0) {
1266 			if (!ca->open)
1267 				break;
1268 
1269 			/*
1270 			 * if a CAMCHANGE occurred at some point, do not do any
1271 			 * more processing of this slot
1272 			 */
1273 			if (dvb_ca_en50221_check_camstatus(ca, slot)) {
1274 				/*
1275 				 * we don't want to sleep on the next iteration
1276 				 * so we can handle the cam change
1277 				 */
1278 				ca->wakeup = 1;
1279 				break;
1280 			}
1281 
1282 			/* check if we've hit our limit this time */
1283 			if (++pktcount >= MAX_RX_PACKETS_PER_ITERATION) {
1284 				/*
1285 				 * don't sleep; there is likely to be more data
1286 				 * to read
1287 				 */
1288 				ca->wakeup = 1;
1289 				break;
1290 			}
1291 		}
1292 		break;
1293 	}
1294 
1295 	mutex_unlock(&sl->slot_lock);
1296 }
1297 
1298 /*
1299  * Kernel thread which monitors CA slots for CAM changes, and performs data
1300  * transfers.
1301  */
dvb_ca_en50221_thread(void * data)1302 static int dvb_ca_en50221_thread(void *data)
1303 {
1304 	struct dvb_ca_private *ca = data;
1305 	int slot;
1306 
1307 	dprintk("%s\n", __func__);
1308 
1309 	/* choose the correct initial delay */
1310 	dvb_ca_en50221_thread_update_delay(ca);
1311 
1312 	/* main loop */
1313 	while (!kthread_should_stop()) {
1314 		/* sleep for a bit */
1315 		if (!ca->wakeup) {
1316 			set_current_state(TASK_INTERRUPTIBLE);
1317 			schedule_timeout(ca->delay);
1318 			if (kthread_should_stop())
1319 				return 0;
1320 		}
1321 		ca->wakeup = 0;
1322 
1323 		/* go through all the slots processing them */
1324 		for (slot = 0; slot < ca->slot_count; slot++)
1325 			dvb_ca_en50221_thread_state_machine(ca, slot);
1326 	}
1327 
1328 	return 0;
1329 }
1330 
1331 /* ************************************************************************** */
1332 /* EN50221 IO interface functions */
1333 
1334 /**
1335  * Real ioctl implementation.
1336  * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
1337  *
1338  * @file: File concerned.
1339  * @cmd: IOCTL command.
1340  * @parg: Associated argument.
1341  *
1342  * return: 0 on success, <0 on error.
1343  */
dvb_ca_en50221_io_do_ioctl(struct file * file,unsigned int cmd,void * parg)1344 static int dvb_ca_en50221_io_do_ioctl(struct file *file,
1345 				      unsigned int cmd, void *parg)
1346 {
1347 	struct dvb_device *dvbdev = file->private_data;
1348 	struct dvb_ca_private *ca = dvbdev->priv;
1349 	int err = 0;
1350 	int slot;
1351 
1352 	dprintk("%s\n", __func__);
1353 
1354 	if (mutex_lock_interruptible(&ca->ioctl_mutex))
1355 		return -ERESTARTSYS;
1356 
1357 	switch (cmd) {
1358 	case CA_RESET:
1359 		for (slot = 0; slot < ca->slot_count; slot++) {
1360 			struct dvb_ca_slot *sl = &ca->slot_info[slot];
1361 
1362 			mutex_lock(&sl->slot_lock);
1363 			if (sl->slot_state != DVB_CA_SLOTSTATE_NONE) {
1364 				dvb_ca_en50221_slot_shutdown(ca, slot);
1365 				if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
1366 					dvb_ca_en50221_camchange_irq(ca->pub,
1367 								     slot,
1368 								     DVB_CA_EN50221_CAMCHANGE_INSERTED);
1369 			}
1370 			mutex_unlock(&sl->slot_lock);
1371 		}
1372 		ca->next_read_slot = 0;
1373 		dvb_ca_en50221_thread_wakeup(ca);
1374 		break;
1375 
1376 	case CA_GET_CAP: {
1377 		struct ca_caps *caps = parg;
1378 
1379 		caps->slot_num = ca->slot_count;
1380 		caps->slot_type = CA_CI_LINK;
1381 		caps->descr_num = 0;
1382 		caps->descr_type = 0;
1383 		break;
1384 	}
1385 
1386 	case CA_GET_SLOT_INFO: {
1387 		struct ca_slot_info *info = parg;
1388 		struct dvb_ca_slot *sl;
1389 
1390 		slot = info->num;
1391 		if ((slot >= ca->slot_count) || (slot < 0)) {
1392 			err = -EINVAL;
1393 			goto out_unlock;
1394 		}
1395 
1396 		info->type = CA_CI_LINK;
1397 		info->flags = 0;
1398 		sl = &ca->slot_info[slot];
1399 		if ((sl->slot_state != DVB_CA_SLOTSTATE_NONE) &&
1400 		    (sl->slot_state != DVB_CA_SLOTSTATE_INVALID)) {
1401 			info->flags = CA_CI_MODULE_PRESENT;
1402 		}
1403 		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING)
1404 			info->flags |= CA_CI_MODULE_READY;
1405 		break;
1406 	}
1407 
1408 	default:
1409 		err = -EINVAL;
1410 		break;
1411 	}
1412 
1413 out_unlock:
1414 	mutex_unlock(&ca->ioctl_mutex);
1415 	return err;
1416 }
1417 
1418 /**
1419  * Wrapper for ioctl implementation.
1420  *
1421  * @file: File concerned.
1422  * @cmd: IOCTL command.
1423  * @arg: Associated argument.
1424  *
1425  * return: 0 on success, <0 on error.
1426  */
dvb_ca_en50221_io_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1427 static long dvb_ca_en50221_io_ioctl(struct file *file,
1428 				    unsigned int cmd, unsigned long arg)
1429 {
1430 	return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
1431 }
1432 
1433 /**
1434  * Implementation of write() syscall.
1435  *
1436  * @file: File structure.
1437  * @buf: Source buffer.
1438  * @count: Size of source buffer.
1439  * @ppos: Position in file (ignored).
1440  *
1441  * return: Number of bytes read, or <0 on error.
1442  */
dvb_ca_en50221_io_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1443 static ssize_t dvb_ca_en50221_io_write(struct file *file,
1444 				       const char __user *buf, size_t count,
1445 				       loff_t *ppos)
1446 {
1447 	struct dvb_device *dvbdev = file->private_data;
1448 	struct dvb_ca_private *ca = dvbdev->priv;
1449 	struct dvb_ca_slot *sl;
1450 	u8 slot, connection_id;
1451 	int status;
1452 	u8 fragbuf[HOST_LINK_BUF_SIZE];
1453 	int fragpos = 0;
1454 	int fraglen;
1455 	unsigned long timeout;
1456 	int written;
1457 
1458 	dprintk("%s\n", __func__);
1459 
1460 	/*
1461 	 * Incoming packet has a 2 byte header.
1462 	 * hdr[0] = slot_id, hdr[1] = connection_id
1463 	 */
1464 	if (count < 2)
1465 		return -EINVAL;
1466 
1467 	/* extract slot & connection id */
1468 	if (copy_from_user(&slot, buf, 1))
1469 		return -EFAULT;
1470 	if (copy_from_user(&connection_id, buf + 1, 1))
1471 		return -EFAULT;
1472 	buf += 2;
1473 	count -= 2;
1474 
1475 	if (slot >= ca->slot_count)
1476 		return -EINVAL;
1477 	slot = array_index_nospec(slot, ca->slot_count);
1478 	sl = &ca->slot_info[slot];
1479 
1480 	/* check if the slot is actually running */
1481 	if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
1482 		return -EINVAL;
1483 
1484 	/* fragment the packets & store in the buffer */
1485 	while (fragpos < count) {
1486 		fraglen = sl->link_buf_size - 2;
1487 		if (fraglen < 0)
1488 			break;
1489 		if (fraglen > HOST_LINK_BUF_SIZE - 2)
1490 			fraglen = HOST_LINK_BUF_SIZE - 2;
1491 		if ((count - fragpos) < fraglen)
1492 			fraglen = count - fragpos;
1493 
1494 		fragbuf[0] = connection_id;
1495 		fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
1496 		status = copy_from_user(fragbuf + 2, buf + fragpos, fraglen);
1497 		if (status) {
1498 			status = -EFAULT;
1499 			goto exit;
1500 		}
1501 
1502 		timeout = jiffies + HZ / 2;
1503 		written = 0;
1504 		while (!time_after(jiffies, timeout)) {
1505 			/*
1506 			 * check the CAM hasn't been removed/reset in the
1507 			 * meantime
1508 			 */
1509 			if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING) {
1510 				status = -EIO;
1511 				goto exit;
1512 			}
1513 
1514 			mutex_lock(&sl->slot_lock);
1515 			status = dvb_ca_en50221_write_data(ca, slot, fragbuf,
1516 							   fraglen + 2, 0);
1517 			mutex_unlock(&sl->slot_lock);
1518 			if (status == (fraglen + 2)) {
1519 				written = 1;
1520 				break;
1521 			}
1522 			if (status != -EAGAIN)
1523 				goto exit;
1524 
1525 			usleep_range(1000, 1100);
1526 		}
1527 		if (!written) {
1528 			status = -EIO;
1529 			goto exit;
1530 		}
1531 
1532 		fragpos += fraglen;
1533 	}
1534 	status = count + 2;
1535 
1536 exit:
1537 	return status;
1538 }
1539 
1540 /*
1541  * Condition for waking up in dvb_ca_en50221_io_read_condition
1542  */
dvb_ca_en50221_io_read_condition(struct dvb_ca_private * ca,int * result,int * _slot)1543 static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
1544 					    int *result, int *_slot)
1545 {
1546 	int slot;
1547 	int slot_count = 0;
1548 	int idx;
1549 	size_t fraglen;
1550 	int connection_id = -1;
1551 	int found = 0;
1552 	u8 hdr[2];
1553 
1554 	slot = ca->next_read_slot;
1555 	while ((slot_count < ca->slot_count) && (!found)) {
1556 		struct dvb_ca_slot *sl = &ca->slot_info[slot];
1557 
1558 		if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
1559 			goto nextslot;
1560 
1561 		if (!sl->rx_buffer.data)
1562 			return 0;
1563 
1564 		idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
1565 		while (idx != -1) {
1566 			dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
1567 			if (connection_id == -1)
1568 				connection_id = hdr[0];
1569 			if ((hdr[0] == connection_id) &&
1570 			    ((hdr[1] & 0x80) == 0)) {
1571 				*_slot = slot;
1572 				found = 1;
1573 				break;
1574 			}
1575 
1576 			idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx,
1577 						      &fraglen);
1578 		}
1579 
1580 nextslot:
1581 		slot = (slot + 1) % ca->slot_count;
1582 		slot_count++;
1583 	}
1584 
1585 	ca->next_read_slot = slot;
1586 	return found;
1587 }
1588 
1589 /**
1590  * Implementation of read() syscall.
1591  *
1592  * @file: File structure.
1593  * @buf: Destination buffer.
1594  * @count: Size of destination buffer.
1595  * @ppos: Position in file (ignored).
1596  *
1597  * return: Number of bytes read, or <0 on error.
1598  */
dvb_ca_en50221_io_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1599 static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user *buf,
1600 				      size_t count, loff_t *ppos)
1601 {
1602 	struct dvb_device *dvbdev = file->private_data;
1603 	struct dvb_ca_private *ca = dvbdev->priv;
1604 	struct dvb_ca_slot *sl;
1605 	int status;
1606 	int result = 0;
1607 	u8 hdr[2];
1608 	int slot;
1609 	int connection_id = -1;
1610 	size_t idx, idx2;
1611 	int last_fragment = 0;
1612 	size_t fraglen;
1613 	int pktlen;
1614 	int dispose = 0;
1615 
1616 	dprintk("%s\n", __func__);
1617 
1618 	/*
1619 	 * Outgoing packet has a 2 byte header.
1620 	 * hdr[0] = slot_id, hdr[1] = connection_id
1621 	 */
1622 	if (count < 2)
1623 		return -EINVAL;
1624 
1625 	/* wait for some data */
1626 	status = dvb_ca_en50221_io_read_condition(ca, &result, &slot);
1627 	if (status == 0) {
1628 		/* if we're in nonblocking mode, exit immediately */
1629 		if (file->f_flags & O_NONBLOCK)
1630 			return -EWOULDBLOCK;
1631 
1632 		/* wait for some data */
1633 		status = wait_event_interruptible(ca->wait_queue,
1634 						  dvb_ca_en50221_io_read_condition
1635 						  (ca, &result, &slot));
1636 	}
1637 	if ((status < 0) || (result < 0)) {
1638 		if (result)
1639 			return result;
1640 		return status;
1641 	}
1642 
1643 	sl = &ca->slot_info[slot];
1644 	idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
1645 	pktlen = 2;
1646 	do {
1647 		if (idx == -1) {
1648 			pr_err("dvb_ca adapter %d: BUG: read packet ended before last_fragment encountered\n",
1649 			       ca->dvbdev->adapter->num);
1650 			status = -EIO;
1651 			goto exit;
1652 		}
1653 
1654 		dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
1655 		if (connection_id == -1)
1656 			connection_id = hdr[0];
1657 		if (hdr[0] == connection_id) {
1658 			if (pktlen < count) {
1659 				if ((pktlen + fraglen - 2) > count)
1660 					fraglen = count - pktlen;
1661 				else
1662 					fraglen -= 2;
1663 
1664 				status =
1665 				   dvb_ringbuffer_pkt_read_user(&sl->rx_buffer,
1666 								idx, 2,
1667 								buf + pktlen,
1668 								fraglen);
1669 				if (status < 0)
1670 					goto exit;
1671 
1672 				pktlen += fraglen;
1673 			}
1674 
1675 			if ((hdr[1] & 0x80) == 0)
1676 				last_fragment = 1;
1677 			dispose = 1;
1678 		}
1679 
1680 		idx2 = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx, &fraglen);
1681 		if (dispose)
1682 			dvb_ringbuffer_pkt_dispose(&sl->rx_buffer, idx);
1683 		idx = idx2;
1684 		dispose = 0;
1685 	} while (!last_fragment);
1686 
1687 	hdr[0] = slot;
1688 	hdr[1] = connection_id;
1689 	status = copy_to_user(buf, hdr, 2);
1690 	if (status) {
1691 		status = -EFAULT;
1692 		goto exit;
1693 	}
1694 	status = pktlen;
1695 
1696 exit:
1697 	return status;
1698 }
1699 
1700 /**
1701  * Implementation of file open syscall.
1702  *
1703  * @inode: Inode concerned.
1704  * @file: File concerned.
1705  *
1706  * return: 0 on success, <0 on failure.
1707  */
dvb_ca_en50221_io_open(struct inode * inode,struct file * file)1708 static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
1709 {
1710 	struct dvb_device *dvbdev = file->private_data;
1711 	struct dvb_ca_private *ca = dvbdev->priv;
1712 	int err;
1713 	int i;
1714 
1715 	dprintk("%s\n", __func__);
1716 
1717 	mutex_lock(&ca->remove_mutex);
1718 
1719 	if (ca->exit) {
1720 		mutex_unlock(&ca->remove_mutex);
1721 		return -ENODEV;
1722 	}
1723 
1724 	if (!try_module_get(ca->pub->owner)) {
1725 		mutex_unlock(&ca->remove_mutex);
1726 		return -EIO;
1727 	}
1728 
1729 	err = dvb_generic_open(inode, file);
1730 	if (err < 0) {
1731 		module_put(ca->pub->owner);
1732 		mutex_unlock(&ca->remove_mutex);
1733 		return err;
1734 	}
1735 
1736 	for (i = 0; i < ca->slot_count; i++) {
1737 		struct dvb_ca_slot *sl = &ca->slot_info[i];
1738 
1739 		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING) {
1740 			if (!sl->rx_buffer.data) {
1741 				/*
1742 				 * it is safe to call this here without locks
1743 				 * because ca->open == 0. Data is not read in
1744 				 * this case
1745 				 */
1746 				dvb_ringbuffer_flush(&sl->rx_buffer);
1747 			}
1748 		}
1749 	}
1750 
1751 	ca->open = 1;
1752 	dvb_ca_en50221_thread_update_delay(ca);
1753 	dvb_ca_en50221_thread_wakeup(ca);
1754 
1755 	dvb_ca_private_get(ca);
1756 
1757 	mutex_unlock(&ca->remove_mutex);
1758 	return 0;
1759 }
1760 
1761 /**
1762  * Implementation of file close syscall.
1763  *
1764  * @inode: Inode concerned.
1765  * @file: File concerned.
1766  *
1767  * return: 0 on success, <0 on failure.
1768  */
dvb_ca_en50221_io_release(struct inode * inode,struct file * file)1769 static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
1770 {
1771 	struct dvb_device *dvbdev = file->private_data;
1772 	struct dvb_ca_private *ca = dvbdev->priv;
1773 	int err;
1774 
1775 	dprintk("%s\n", __func__);
1776 
1777 	mutex_lock(&ca->remove_mutex);
1778 
1779 	/* mark the CA device as closed */
1780 	ca->open = 0;
1781 	dvb_ca_en50221_thread_update_delay(ca);
1782 
1783 	err = dvb_generic_release(inode, file);
1784 
1785 	module_put(ca->pub->owner);
1786 
1787 	dvb_ca_private_put(ca);
1788 
1789 	if (dvbdev->users == 1 && ca->exit == 1) {
1790 		mutex_unlock(&ca->remove_mutex);
1791 		wake_up(&dvbdev->wait_queue);
1792 	} else {
1793 		mutex_unlock(&ca->remove_mutex);
1794 	}
1795 
1796 	return err;
1797 }
1798 
1799 /**
1800  * Implementation of poll() syscall.
1801  *
1802  * @file: File concerned.
1803  * @wait: poll wait table.
1804  *
1805  * return: Standard poll mask.
1806  */
dvb_ca_en50221_io_poll(struct file * file,poll_table * wait)1807 static __poll_t dvb_ca_en50221_io_poll(struct file *file, poll_table *wait)
1808 {
1809 	struct dvb_device *dvbdev = file->private_data;
1810 	struct dvb_ca_private *ca = dvbdev->priv;
1811 	__poll_t mask = 0;
1812 	int slot;
1813 	int result = 0;
1814 
1815 	dprintk("%s\n", __func__);
1816 
1817 	poll_wait(file, &ca->wait_queue, wait);
1818 
1819 	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
1820 		mask |= EPOLLIN;
1821 
1822 	/* if there is something, return now */
1823 	if (mask)
1824 		return mask;
1825 
1826 	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
1827 		mask |= EPOLLIN;
1828 
1829 	return mask;
1830 }
1831 
1832 static const struct file_operations dvb_ca_fops = {
1833 	.owner = THIS_MODULE,
1834 	.read = dvb_ca_en50221_io_read,
1835 	.write = dvb_ca_en50221_io_write,
1836 	.unlocked_ioctl = dvb_ca_en50221_io_ioctl,
1837 	.open = dvb_ca_en50221_io_open,
1838 	.release = dvb_ca_en50221_io_release,
1839 	.poll = dvb_ca_en50221_io_poll,
1840 	.llseek = noop_llseek,
1841 };
1842 
1843 static const struct dvb_device dvbdev_ca = {
1844 	.priv = NULL,
1845 	.users = 1,
1846 	.readers = 1,
1847 	.writers = 1,
1848 #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
1849 	.name = "dvb-ca-en50221",
1850 #endif
1851 	.fops = &dvb_ca_fops,
1852 };
1853 
1854 /* ************************************************************************** */
1855 /* Initialisation/shutdown functions */
1856 
1857 /**
1858  * Initialise a new DVB CA EN50221 interface device.
1859  *
1860  * @dvb_adapter: DVB adapter to attach the new CA device to.
1861  * @pubca: The dvb_ca instance.
1862  * @flags: Flags describing the CA device (DVB_CA_FLAG_*).
1863  * @slot_count: Number of slots supported.
1864  *
1865  * return: 0 on success, nonzero on failure
1866  */
dvb_ca_en50221_init(struct dvb_adapter * dvb_adapter,struct dvb_ca_en50221 * pubca,int flags,int slot_count)1867 int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
1868 			struct dvb_ca_en50221 *pubca, int flags, int slot_count)
1869 {
1870 	int ret;
1871 	struct dvb_ca_private *ca = NULL;
1872 	int i;
1873 
1874 	dprintk("%s\n", __func__);
1875 
1876 	if (slot_count < 1)
1877 		return -EINVAL;
1878 
1879 	/* initialise the system data */
1880 	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1881 	if (!ca) {
1882 		ret = -ENOMEM;
1883 		goto exit;
1884 	}
1885 	kref_init(&ca->refcount);
1886 	ca->pub = pubca;
1887 	ca->flags = flags;
1888 	ca->slot_count = slot_count;
1889 	ca->slot_info = kcalloc(slot_count, sizeof(struct dvb_ca_slot),
1890 				GFP_KERNEL);
1891 	if (!ca->slot_info) {
1892 		ret = -ENOMEM;
1893 		goto free_ca;
1894 	}
1895 	init_waitqueue_head(&ca->wait_queue);
1896 	ca->open = 0;
1897 	ca->wakeup = 0;
1898 	ca->next_read_slot = 0;
1899 	pubca->private = ca;
1900 
1901 	/* register the DVB device */
1902 	ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca,
1903 				  DVB_DEVICE_CA, 0);
1904 	if (ret)
1905 		goto free_slot_info;
1906 
1907 	/* now initialise each slot */
1908 	for (i = 0; i < slot_count; i++) {
1909 		struct dvb_ca_slot *sl = &ca->slot_info[i];
1910 
1911 		memset(sl, 0, sizeof(struct dvb_ca_slot));
1912 		sl->slot_state = DVB_CA_SLOTSTATE_NONE;
1913 		atomic_set(&sl->camchange_count, 0);
1914 		sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
1915 		mutex_init(&sl->slot_lock);
1916 	}
1917 
1918 	mutex_init(&ca->ioctl_mutex);
1919 	mutex_init(&ca->remove_mutex);
1920 
1921 	if (signal_pending(current)) {
1922 		ret = -EINTR;
1923 		goto unregister_device;
1924 	}
1925 	mb();
1926 
1927 	/* create a kthread for monitoring this CA device */
1928 	ca->thread = kthread_run(dvb_ca_en50221_thread, ca, "kdvb-ca-%i:%i",
1929 				 ca->dvbdev->adapter->num, ca->dvbdev->id);
1930 	if (IS_ERR(ca->thread)) {
1931 		ret = PTR_ERR(ca->thread);
1932 		pr_err("dvb_ca_init: failed to start kernel_thread (%d)\n",
1933 		       ret);
1934 		goto unregister_device;
1935 	}
1936 	return 0;
1937 
1938 unregister_device:
1939 	dvb_unregister_device(ca->dvbdev);
1940 free_slot_info:
1941 	kfree(ca->slot_info);
1942 free_ca:
1943 	kfree(ca);
1944 exit:
1945 	pubca->private = NULL;
1946 	return ret;
1947 }
1948 EXPORT_SYMBOL(dvb_ca_en50221_init);
1949 
1950 /**
1951  * Release a DVB CA EN50221 interface device.
1952  *
1953  * @pubca: The associated dvb_ca instance.
1954  */
dvb_ca_en50221_release(struct dvb_ca_en50221 * pubca)1955 void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
1956 {
1957 	struct dvb_ca_private *ca = pubca->private;
1958 	int i;
1959 
1960 	dprintk("%s\n", __func__);
1961 
1962 	mutex_lock(&ca->remove_mutex);
1963 	ca->exit = 1;
1964 	mutex_unlock(&ca->remove_mutex);
1965 
1966 	if (ca->dvbdev->users < 1)
1967 		wait_event(ca->dvbdev->wait_queue,
1968 				ca->dvbdev->users == 1);
1969 
1970 	/* shutdown the thread if there was one */
1971 	kthread_stop(ca->thread);
1972 
1973 	for (i = 0; i < ca->slot_count; i++)
1974 		dvb_ca_en50221_slot_shutdown(ca, i);
1975 
1976 	dvb_remove_device(ca->dvbdev);
1977 	dvb_ca_private_put(ca);
1978 	pubca->private = NULL;
1979 }
1980 EXPORT_SYMBOL(dvb_ca_en50221_release);
1981