1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ngene-dvb.c: nGene PCIe bridge driver - DVB functions
4  *
5  * Copyright (C) 2005-2007 Micronas
6  *
7  * Copyright (C) 2008-2009 Ralph Metzler <rjkm@metzlerbros.de>
8  *                         Modifications for new nGene firmware,
9  *                         support for EEPROM-copying,
10  *                         support for new dual DVB-S2 card prototype
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/delay.h>
16 #include <linux/slab.h>
17 #include <linux/poll.h>
18 #include <linux/io.h>
19 #include <asm/div64.h>
20 #include <linux/pci.h>
21 #include <linux/timer.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/firmware.h>
24 #include <linux/vmalloc.h>
25 
26 #include "ngene.h"
27 
28 static int ci_tsfix = 1;
29 module_param(ci_tsfix, int, 0444);
30 MODULE_PARM_DESC(ci_tsfix, "Detect and fix TS buffer offset shifts in conjunction with CI expansions (default: 1/enabled)");
31 
32 /****************************************************************************/
33 /* COMMAND API interface ****************************************************/
34 /****************************************************************************/
35 
36 static ssize_t ts_write(struct file *file, const char __user *buf,
37 			size_t count, loff_t *ppos)
38 {
39 	struct dvb_device *dvbdev = file->private_data;
40 	struct ngene_channel *chan = dvbdev->priv;
41 	struct ngene *dev = chan->dev;
42 
43 	if (wait_event_interruptible(dev->tsout_rbuf.queue,
44 				     dvb_ringbuffer_free
45 				     (&dev->tsout_rbuf) >= count) < 0)
46 		return 0;
47 
48 	dvb_ringbuffer_write_user(&dev->tsout_rbuf, buf, count);
49 
50 	return count;
51 }
52 
53 static ssize_t ts_read(struct file *file, char __user *buf,
54 		       size_t count, loff_t *ppos)
55 {
56 	struct dvb_device *dvbdev = file->private_data;
57 	struct ngene_channel *chan = dvbdev->priv;
58 	struct ngene *dev = chan->dev;
59 	int left, avail;
60 
61 	left = count;
62 	while (left) {
63 		if (wait_event_interruptible(
64 			    dev->tsin_rbuf.queue,
65 			    dvb_ringbuffer_avail(&dev->tsin_rbuf) > 0) < 0)
66 			return -EAGAIN;
67 		avail = dvb_ringbuffer_avail(&dev->tsin_rbuf);
68 		if (avail > left)
69 			avail = left;
70 		dvb_ringbuffer_read_user(&dev->tsin_rbuf, buf, avail);
71 		left -= avail;
72 		buf += avail;
73 	}
74 	return count;
75 }
76 
77 static __poll_t ts_poll(struct file *file, poll_table *wait)
78 {
79 	struct dvb_device *dvbdev = file->private_data;
80 	struct ngene_channel *chan = dvbdev->priv;
81 	struct ngene *dev = chan->dev;
82 	struct dvb_ringbuffer *rbuf = &dev->tsin_rbuf;
83 	struct dvb_ringbuffer *wbuf = &dev->tsout_rbuf;
84 	__poll_t mask = 0;
85 
86 	poll_wait(file, &rbuf->queue, wait);
87 	poll_wait(file, &wbuf->queue, wait);
88 
89 	if (!dvb_ringbuffer_empty(rbuf))
90 		mask |= EPOLLIN | EPOLLRDNORM;
91 	if (dvb_ringbuffer_free(wbuf) >= 188)
92 		mask |= EPOLLOUT | EPOLLWRNORM;
93 
94 	return mask;
95 }
96 
97 static const struct file_operations ci_fops = {
98 	.owner   = THIS_MODULE,
99 	.read    = ts_read,
100 	.write   = ts_write,
101 	.open    = dvb_generic_open,
102 	.release = dvb_generic_release,
103 	.poll    = ts_poll,
104 	.mmap    = NULL,
105 };
106 
107 struct dvb_device ngene_dvbdev_ci = {
108 	.priv    = NULL,
109 	.readers = 1,
110 	.writers = 1,
111 	.users   = 2,
112 	.fops    = &ci_fops,
113 };
114 
115 
116 /****************************************************************************/
117 /* DVB functions and API interface ******************************************/
118 /****************************************************************************/
119 
120 static void swap_buffer(u32 *p, u32 len)
121 {
122 	while (len) {
123 		*p = swab32(*p);
124 		p++;
125 		len -= 4;
126 	}
127 }
128 
129 /* start of filler packet */
130 static u8 fill_ts[] = { 0x47, 0x1f, 0xff, 0x10, TS_FILLER };
131 
132 static int tsin_find_offset(void *buf, u32 len)
133 {
134 	int i, l;
135 
136 	l = len - sizeof(fill_ts);
137 	if (l <= 0)
138 		return -1;
139 
140 	for (i = 0; i < l; i++) {
141 		if (((char *)buf)[i] == 0x47) {
142 			if (!memcmp(buf + i, fill_ts, sizeof(fill_ts)))
143 				return i % 188;
144 		}
145 	}
146 
147 	return -1;
148 }
149 
150 static inline void tsin_copy_stripped(struct ngene *dev, void *buf)
151 {
152 	if (memcmp(buf, fill_ts, sizeof(fill_ts)) != 0) {
153 		if (dvb_ringbuffer_free(&dev->tsin_rbuf) >= 188) {
154 			dvb_ringbuffer_write(&dev->tsin_rbuf, buf, 188);
155 			wake_up(&dev->tsin_rbuf.queue);
156 		}
157 	}
158 }
159 
160 void *tsin_exchange(void *priv, void *buf, u32 len, u32 clock, u32 flags)
161 {
162 	struct ngene_channel *chan = priv;
163 	struct ngene *dev = chan->dev;
164 	int tsoff;
165 
166 	if (flags & DF_SWAP32)
167 		swap_buffer(buf, len);
168 
169 	if (dev->ci.en && chan->number == 2) {
170 		/* blindly copy buffers if ci_tsfix is disabled */
171 		if (!ci_tsfix) {
172 			while (len >= 188) {
173 				tsin_copy_stripped(dev, buf);
174 
175 				buf += 188;
176 				len -= 188;
177 			}
178 			return NULL;
179 		}
180 
181 		/* ci_tsfix = 1 */
182 
183 		/*
184 		 * since the remainder of the TS packet which got cut off
185 		 * in the previous tsin_exchange() run is at the beginning
186 		 * of the new TS buffer, append this to the temp buffer and
187 		 * send it to the DVB ringbuffer afterwards.
188 		 */
189 		if (chan->tsin_offset) {
190 			memcpy(&chan->tsin_buffer[(188 - chan->tsin_offset)],
191 			       buf, chan->tsin_offset);
192 			tsin_copy_stripped(dev, &chan->tsin_buffer);
193 
194 			buf += chan->tsin_offset;
195 			len -= chan->tsin_offset;
196 		}
197 
198 		/*
199 		 * copy TS packets to the DVB ringbuffer and detect new offset
200 		 * shifts by checking for a valid TS SYNC byte
201 		 */
202 		while (len >= 188) {
203 			if (*((char *)buf) != 0x47) {
204 				/*
205 				 * no SYNC header, find new offset shift
206 				 * (max. 188 bytes, tsoff will be mod 188)
207 				 */
208 				tsoff = tsin_find_offset(buf, len);
209 				if (tsoff > 0) {
210 					chan->tsin_offset += tsoff;
211 					chan->tsin_offset %= 188;
212 
213 					buf += tsoff;
214 					len -= tsoff;
215 
216 					dev_info(&dev->pci_dev->dev,
217 						 "%s(): tsin_offset shift by %d on channel %d\n",
218 						 __func__, tsoff,
219 						 chan->number);
220 
221 					/*
222 					 * offset corrected. re-check remaining
223 					 * len for a full TS frame, break and
224 					 * skip to fragment handling if < 188.
225 					 */
226 					if (len < 188)
227 						break;
228 				}
229 			}
230 
231 			tsin_copy_stripped(dev, buf);
232 
233 			buf += 188;
234 			len -= 188;
235 		}
236 
237 		/*
238 		 * if a fragment is left, copy to temp buffer. The remainder
239 		 * will be appended in the next tsin_exchange() iteration.
240 		 */
241 		if (len > 0 && len < 188)
242 			memcpy(&chan->tsin_buffer, buf, len);
243 
244 		return NULL;
245 	}
246 
247 	if (chan->users > 0)
248 		dvb_dmx_swfilter(&chan->demux, buf, len);
249 
250 	return NULL;
251 }
252 
253 void *tsout_exchange(void *priv, void *buf, u32 len, u32 clock, u32 flags)
254 {
255 	struct ngene_channel *chan = priv;
256 	struct ngene *dev = chan->dev;
257 	u32 alen;
258 
259 	alen = dvb_ringbuffer_avail(&dev->tsout_rbuf);
260 	alen -= alen % 188;
261 
262 	if (alen < len)
263 		FillTSBuffer(buf + alen, len - alen, flags);
264 	else
265 		alen = len;
266 	dvb_ringbuffer_read(&dev->tsout_rbuf, buf, alen);
267 	if (flags & DF_SWAP32)
268 		swap_buffer((u32 *)buf, alen);
269 	wake_up_interruptible(&dev->tsout_rbuf.queue);
270 	return buf;
271 }
272 
273 
274 
275 int ngene_start_feed(struct dvb_demux_feed *dvbdmxfeed)
276 {
277 	struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
278 	struct ngene_channel *chan = dvbdmx->priv;
279 
280 	if (chan->users == 0) {
281 		if (!chan->dev->cmd_timeout_workaround || !chan->running)
282 			set_transfer(chan, 1);
283 	}
284 
285 	return ++chan->users;
286 }
287 
288 int ngene_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
289 {
290 	struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
291 	struct ngene_channel *chan = dvbdmx->priv;
292 
293 	if (--chan->users)
294 		return chan->users;
295 
296 	if (!chan->dev->cmd_timeout_workaround)
297 		set_transfer(chan, 0);
298 
299 	return 0;
300 }
301 
302 int my_dvb_dmx_ts_card_init(struct dvb_demux *dvbdemux, char *id,
303 			    int (*start_feed)(struct dvb_demux_feed *),
304 			    int (*stop_feed)(struct dvb_demux_feed *),
305 			    void *priv)
306 {
307 	dvbdemux->priv = priv;
308 
309 	dvbdemux->filternum = 256;
310 	dvbdemux->feednum = 256;
311 	dvbdemux->start_feed = start_feed;
312 	dvbdemux->stop_feed = stop_feed;
313 	dvbdemux->write_to_decoder = NULL;
314 	dvbdemux->dmx.capabilities = (DMX_TS_FILTERING |
315 				      DMX_SECTION_FILTERING |
316 				      DMX_MEMORY_BASED_FILTERING);
317 	return dvb_dmx_init(dvbdemux);
318 }
319 
320 int my_dvb_dmxdev_ts_card_init(struct dmxdev *dmxdev,
321 			       struct dvb_demux *dvbdemux,
322 			       struct dmx_frontend *hw_frontend,
323 			       struct dmx_frontend *mem_frontend,
324 			       struct dvb_adapter *dvb_adapter)
325 {
326 	int ret;
327 
328 	dmxdev->filternum = 256;
329 	dmxdev->demux = &dvbdemux->dmx;
330 	dmxdev->capabilities = 0;
331 	ret = dvb_dmxdev_init(dmxdev, dvb_adapter);
332 	if (ret < 0)
333 		return ret;
334 
335 	hw_frontend->source = DMX_FRONTEND_0;
336 	dvbdemux->dmx.add_frontend(&dvbdemux->dmx, hw_frontend);
337 	mem_frontend->source = DMX_MEMORY_FE;
338 	dvbdemux->dmx.add_frontend(&dvbdemux->dmx, mem_frontend);
339 	return dvbdemux->dmx.connect_frontend(&dvbdemux->dmx, hw_frontend);
340 }
341