xref: /openbmc/linux/drivers/media/i2c/saa6588.c (revision feac8c8b)
1 /*
2     Driver for SAA6588 RDS decoder
3 
4     (c) 2005 Hans J. Koch
5 
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10 
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15 
16     You should have received a copy of the GNU General Public License
17     along with this program; if not, write to the Free Software
18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 
21 
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/i2c.h>
25 #include <linux/types.h>
26 #include <linux/videodev2.h>
27 #include <linux/init.h>
28 #include <linux/errno.h>
29 #include <linux/slab.h>
30 #include <linux/poll.h>
31 #include <linux/wait.h>
32 #include <linux/uaccess.h>
33 
34 #include <media/i2c/saa6588.h>
35 #include <media/v4l2-device.h>
36 
37 
38 /* insmod options */
39 static unsigned int debug;
40 static unsigned int xtal;
41 static unsigned int mmbs;
42 static unsigned int plvl;
43 static unsigned int bufblocks = 100;
44 
45 module_param(debug, int, 0644);
46 MODULE_PARM_DESC(debug, "enable debug messages");
47 module_param(xtal, int, 0);
48 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
49 module_param(mmbs, int, 0);
50 MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
51 module_param(plvl, int, 0);
52 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
53 module_param(bufblocks, int, 0);
54 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
55 
56 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
57 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
58 
59 MODULE_LICENSE("GPL");
60 
61 /* ---------------------------------------------------------------------- */
62 
63 #define UNSET       (-1U)
64 #define PREFIX      "saa6588: "
65 #define dprintk     if (debug) printk
66 
67 struct saa6588 {
68 	struct v4l2_subdev sd;
69 	struct delayed_work work;
70 	spinlock_t lock;
71 	unsigned char *buffer;
72 	unsigned int buf_size;
73 	unsigned int rd_index;
74 	unsigned int wr_index;
75 	unsigned int block_count;
76 	unsigned char last_blocknum;
77 	wait_queue_head_t read_queue;
78 	int data_available_for_read;
79 	u8 sync;
80 };
81 
82 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
83 {
84 	return container_of(sd, struct saa6588, sd);
85 }
86 
87 /* ---------------------------------------------------------------------- */
88 
89 /*
90  * SAA6588 defines
91  */
92 
93 /* Initialization and mode control byte (0w) */
94 
95 /* bit 0+1 (DAC0/DAC1) */
96 #define cModeStandard           0x00
97 #define cModeFastPI             0x01
98 #define cModeReducedRequest     0x02
99 #define cModeInvalid            0x03
100 
101 /* bit 2 (RBDS) */
102 #define cProcessingModeRDS      0x00
103 #define cProcessingModeRBDS     0x04
104 
105 /* bit 3+4 (SYM0/SYM1) */
106 #define cErrCorrectionNone      0x00
107 #define cErrCorrection2Bits     0x08
108 #define cErrCorrection5Bits     0x10
109 #define cErrCorrectionNoneRBDS  0x18
110 
111 /* bit 5 (NWSY) */
112 #define cSyncNormal             0x00
113 #define cSyncRestart            0x20
114 
115 /* bit 6 (TSQD) */
116 #define cSigQualityDetectOFF    0x00
117 #define cSigQualityDetectON     0x40
118 
119 /* bit 7 (SQCM) */
120 #define cSigQualityTriggered    0x00
121 #define cSigQualityContinous    0x80
122 
123 /* Pause level and flywheel control byte (1w) */
124 
125 /* bits 0..5 (FEB0..FEB5) */
126 #define cFlywheelMaxBlocksMask  0x3F
127 #define cFlywheelDefault        0x20
128 
129 /* bits 6+7 (PL0/PL1) */
130 #define cPauseLevel_11mV	0x00
131 #define cPauseLevel_17mV        0x40
132 #define cPauseLevel_27mV        0x80
133 #define cPauseLevel_43mV        0xC0
134 
135 /* Pause time/oscillator frequency/quality detector control byte (1w) */
136 
137 /* bits 0..4 (SQS0..SQS4) */
138 #define cQualityDetectSensMask  0x1F
139 #define cQualityDetectDefault   0x0F
140 
141 /* bit 5 (SOSC) */
142 #define cSelectOscFreqOFF	0x00
143 #define cSelectOscFreqON	0x20
144 
145 /* bit 6+7 (PTF0/PTF1) */
146 #define cOscFreq_4332kHz	0x00
147 #define cOscFreq_8664kHz	0x40
148 #define cOscFreq_12996kHz	0x80
149 #define cOscFreq_17328kHz	0xC0
150 
151 /* ---------------------------------------------------------------------- */
152 
153 static bool block_from_buf(struct saa6588 *s, unsigned char *buf)
154 {
155 	int i;
156 
157 	if (s->rd_index == s->wr_index) {
158 		if (debug > 2)
159 			dprintk(PREFIX "Read: buffer empty.\n");
160 		return false;
161 	}
162 
163 	if (debug > 2) {
164 		dprintk(PREFIX "Read: ");
165 		for (i = s->rd_index; i < s->rd_index + 3; i++)
166 			dprintk("0x%02x ", s->buffer[i]);
167 	}
168 
169 	memcpy(buf, &s->buffer[s->rd_index], 3);
170 
171 	s->rd_index += 3;
172 	if (s->rd_index >= s->buf_size)
173 		s->rd_index = 0;
174 	s->block_count--;
175 
176 	if (debug > 2)
177 		dprintk("%d blocks total.\n", s->block_count);
178 
179 	return true;
180 }
181 
182 static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
183 {
184 	unsigned char __user *buf_ptr = a->buffer;
185 	unsigned char buf[3];
186 	unsigned long flags;
187 	unsigned int rd_blocks;
188 	unsigned int i;
189 
190 	a->result = 0;
191 	if (!a->buffer)
192 		return;
193 
194 	while (!a->nonblocking && !s->data_available_for_read) {
195 		int ret = wait_event_interruptible(s->read_queue,
196 					     s->data_available_for_read);
197 		if (ret == -ERESTARTSYS) {
198 			a->result = -EINTR;
199 			return;
200 		}
201 	}
202 
203 	rd_blocks = a->block_count;
204 	spin_lock_irqsave(&s->lock, flags);
205 	if (rd_blocks > s->block_count)
206 		rd_blocks = s->block_count;
207 	spin_unlock_irqrestore(&s->lock, flags);
208 
209 	if (!rd_blocks)
210 		return;
211 
212 	for (i = 0; i < rd_blocks; i++) {
213 		bool got_block;
214 
215 		spin_lock_irqsave(&s->lock, flags);
216 		got_block = block_from_buf(s, buf);
217 		spin_unlock_irqrestore(&s->lock, flags);
218 		if (!got_block)
219 			break;
220 		if (copy_to_user(buf_ptr, buf, 3)) {
221 			a->result = -EFAULT;
222 			return;
223 		}
224 		buf_ptr += 3;
225 		a->result += 3;
226 	}
227 	spin_lock_irqsave(&s->lock, flags);
228 	s->data_available_for_read = (s->block_count > 0);
229 	spin_unlock_irqrestore(&s->lock, flags);
230 }
231 
232 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
233 {
234 	unsigned int i;
235 
236 	if (debug > 3)
237 		dprintk(PREFIX "New block: ");
238 
239 	for (i = 0; i < 3; ++i) {
240 		if (debug > 3)
241 			dprintk("0x%02x ", blockbuf[i]);
242 		s->buffer[s->wr_index] = blockbuf[i];
243 		s->wr_index++;
244 	}
245 
246 	if (s->wr_index >= s->buf_size)
247 		s->wr_index = 0;
248 
249 	if (s->wr_index == s->rd_index) {
250 		s->rd_index += 3;
251 		if (s->rd_index >= s->buf_size)
252 			s->rd_index = 0;
253 	} else
254 		s->block_count++;
255 
256 	if (debug > 3)
257 		dprintk("%d blocks total.\n", s->block_count);
258 }
259 
260 static void saa6588_i2c_poll(struct saa6588 *s)
261 {
262 	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
263 	unsigned long flags;
264 	unsigned char tmpbuf[6];
265 	unsigned char blocknum;
266 	unsigned char tmp;
267 
268 	/* Although we only need 3 bytes, we have to read at least 6.
269 	   SAA6588 returns garbage otherwise. */
270 	if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
271 		if (debug > 1)
272 			dprintk(PREFIX "read error!\n");
273 		return;
274 	}
275 
276 	s->sync = tmpbuf[0] & 0x10;
277 	if (!s->sync)
278 		return;
279 	blocknum = tmpbuf[0] >> 5;
280 	if (blocknum == s->last_blocknum) {
281 		if (debug > 3)
282 			dprintk("Saw block %d again.\n", blocknum);
283 		return;
284 	}
285 
286 	s->last_blocknum = blocknum;
287 
288 	/*
289 	   Byte order according to v4l2 specification:
290 
291 	   Byte 0: Least Significant Byte of RDS Block
292 	   Byte 1: Most Significant Byte of RDS Block
293 	   Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
294 	   occurred during reception of this block.
295 	   Bit 6: Corrected bit. Indicates that an error was
296 	   corrected for this data block.
297 	   Bits 5-3: Same as bits 0-2.
298 	   Bits 2-0: Block number.
299 
300 	   SAA6588 byte order is Status-MSB-LSB, so we have to swap the
301 	   first and the last of the 3 bytes block.
302 	 */
303 
304 	swap(tmpbuf[2], tmpbuf[0]);
305 
306 	/* Map 'Invalid block E' to 'Invalid Block' */
307 	if (blocknum == 6)
308 		blocknum = V4L2_RDS_BLOCK_INVALID;
309 	/* And if are not in mmbs mode, then 'Block E' is also mapped
310 	   to 'Invalid Block'. As far as I can tell MMBS is discontinued,
311 	   and if there is ever a need to support E blocks, then please
312 	   contact the linux-media mailinglist. */
313 	else if (!mmbs && blocknum == 5)
314 		blocknum = V4L2_RDS_BLOCK_INVALID;
315 	tmp = blocknum;
316 	tmp |= blocknum << 3;	/* Received offset == Offset Name (OK ?) */
317 	if ((tmpbuf[2] & 0x03) == 0x03)
318 		tmp |= V4L2_RDS_BLOCK_ERROR;	 /* uncorrectable error */
319 	else if ((tmpbuf[2] & 0x03) != 0x00)
320 		tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
321 	tmpbuf[2] = tmp;	/* Is this enough ? Should we also check other bits ? */
322 
323 	spin_lock_irqsave(&s->lock, flags);
324 	block_to_buf(s, tmpbuf);
325 	spin_unlock_irqrestore(&s->lock, flags);
326 	s->data_available_for_read = 1;
327 	wake_up_interruptible(&s->read_queue);
328 }
329 
330 static void saa6588_work(struct work_struct *work)
331 {
332 	struct saa6588 *s = container_of(work, struct saa6588, work.work);
333 
334 	saa6588_i2c_poll(s);
335 	schedule_delayed_work(&s->work, msecs_to_jiffies(20));
336 }
337 
338 static void saa6588_configure(struct saa6588 *s)
339 {
340 	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
341 	unsigned char buf[3];
342 	int rc;
343 
344 	buf[0] = cSyncRestart;
345 	if (mmbs)
346 		buf[0] |= cProcessingModeRBDS;
347 
348 	buf[1] = cFlywheelDefault;
349 	switch (plvl) {
350 	case 0:
351 		buf[1] |= cPauseLevel_11mV;
352 		break;
353 	case 1:
354 		buf[1] |= cPauseLevel_17mV;
355 		break;
356 	case 2:
357 		buf[1] |= cPauseLevel_27mV;
358 		break;
359 	case 3:
360 		buf[1] |= cPauseLevel_43mV;
361 		break;
362 	default:		/* nothing */
363 		break;
364 	}
365 
366 	buf[2] = cQualityDetectDefault | cSelectOscFreqON;
367 
368 	switch (xtal) {
369 	case 0:
370 		buf[2] |= cOscFreq_4332kHz;
371 		break;
372 	case 1:
373 		buf[2] |= cOscFreq_8664kHz;
374 		break;
375 	case 2:
376 		buf[2] |= cOscFreq_12996kHz;
377 		break;
378 	case 3:
379 		buf[2] |= cOscFreq_17328kHz;
380 		break;
381 	default:		/* nothing */
382 		break;
383 	}
384 
385 	dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
386 		buf[0], buf[1], buf[2]);
387 
388 	rc = i2c_master_send(client, buf, 3);
389 	if (rc != 3)
390 		printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
391 }
392 
393 /* ---------------------------------------------------------------------- */
394 
395 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
396 {
397 	struct saa6588 *s = to_saa6588(sd);
398 	struct saa6588_command *a = arg;
399 
400 	switch (cmd) {
401 		/* --- close() for /dev/radio --- */
402 	case SAA6588_CMD_CLOSE:
403 		s->data_available_for_read = 1;
404 		wake_up_interruptible(&s->read_queue);
405 		s->data_available_for_read = 0;
406 		a->result = 0;
407 		break;
408 		/* --- read() for /dev/radio --- */
409 	case SAA6588_CMD_READ:
410 		read_from_buf(s, a);
411 		break;
412 		/* --- poll() for /dev/radio --- */
413 	case SAA6588_CMD_POLL:
414 		a->result = 0;
415 		if (s->data_available_for_read)
416 			a->result |= EPOLLIN | EPOLLRDNORM;
417 		poll_wait(a->instance, &s->read_queue, a->event_list);
418 		break;
419 
420 	default:
421 		/* nothing */
422 		return -ENOIOCTLCMD;
423 	}
424 	return 0;
425 }
426 
427 static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
428 {
429 	struct saa6588 *s = to_saa6588(sd);
430 
431 	vt->capability |= V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO;
432 	if (s->sync)
433 		vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
434 	return 0;
435 }
436 
437 static int saa6588_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *vt)
438 {
439 	struct saa6588 *s = to_saa6588(sd);
440 
441 	saa6588_configure(s);
442 	return 0;
443 }
444 
445 /* ----------------------------------------------------------------------- */
446 
447 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
448 	.ioctl = saa6588_ioctl,
449 };
450 
451 static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
452 	.g_tuner = saa6588_g_tuner,
453 	.s_tuner = saa6588_s_tuner,
454 };
455 
456 static const struct v4l2_subdev_ops saa6588_ops = {
457 	.core = &saa6588_core_ops,
458 	.tuner = &saa6588_tuner_ops,
459 };
460 
461 /* ---------------------------------------------------------------------- */
462 
463 static int saa6588_probe(struct i2c_client *client,
464 			 const struct i2c_device_id *id)
465 {
466 	struct saa6588 *s;
467 	struct v4l2_subdev *sd;
468 
469 	v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
470 			client->addr << 1, client->adapter->name);
471 
472 	s = devm_kzalloc(&client->dev, sizeof(*s), GFP_KERNEL);
473 	if (s == NULL)
474 		return -ENOMEM;
475 
476 	s->buf_size = bufblocks * 3;
477 
478 	s->buffer = devm_kzalloc(&client->dev, s->buf_size, GFP_KERNEL);
479 	if (s->buffer == NULL)
480 		return -ENOMEM;
481 	sd = &s->sd;
482 	v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
483 	spin_lock_init(&s->lock);
484 	s->block_count = 0;
485 	s->wr_index = 0;
486 	s->rd_index = 0;
487 	s->last_blocknum = 0xff;
488 	init_waitqueue_head(&s->read_queue);
489 	s->data_available_for_read = 0;
490 
491 	saa6588_configure(s);
492 
493 	/* start polling via eventd */
494 	INIT_DELAYED_WORK(&s->work, saa6588_work);
495 	schedule_delayed_work(&s->work, 0);
496 	return 0;
497 }
498 
499 static int saa6588_remove(struct i2c_client *client)
500 {
501 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
502 	struct saa6588 *s = to_saa6588(sd);
503 
504 	v4l2_device_unregister_subdev(sd);
505 
506 	cancel_delayed_work_sync(&s->work);
507 
508 	return 0;
509 }
510 
511 /* ----------------------------------------------------------------------- */
512 
513 static const struct i2c_device_id saa6588_id[] = {
514 	{ "saa6588", 0 },
515 	{ }
516 };
517 MODULE_DEVICE_TABLE(i2c, saa6588_id);
518 
519 static struct i2c_driver saa6588_driver = {
520 	.driver = {
521 		.name	= "saa6588",
522 	},
523 	.probe		= saa6588_probe,
524 	.remove		= saa6588_remove,
525 	.id_table	= saa6588_id,
526 };
527 
528 module_i2c_driver(saa6588_driver);
529