xref: /openbmc/linux/drivers/media/i2c/saa6588.c (revision 2223cbec)
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 <asm/uaccess.h>
33 
34 #include <media/saa6588.h>
35 #include <media/v4l2-device.h>
36 #include <media/v4l2-chip-ident.h>
37 
38 
39 /* insmod options */
40 static unsigned int debug;
41 static unsigned int xtal;
42 static unsigned int mmbs;
43 static unsigned int plvl;
44 static unsigned int bufblocks = 100;
45 
46 module_param(debug, int, 0644);
47 MODULE_PARM_DESC(debug, "enable debug messages");
48 module_param(xtal, int, 0);
49 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
50 module_param(mmbs, int, 0);
51 MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
52 module_param(plvl, int, 0);
53 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
54 module_param(bufblocks, int, 0);
55 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
56 
57 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
58 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
59 
60 MODULE_LICENSE("GPL");
61 
62 /* ---------------------------------------------------------------------- */
63 
64 #define UNSET       (-1U)
65 #define PREFIX      "saa6588: "
66 #define dprintk     if (debug) printk
67 
68 struct saa6588 {
69 	struct v4l2_subdev sd;
70 	struct delayed_work work;
71 	spinlock_t lock;
72 	unsigned char *buffer;
73 	unsigned int buf_size;
74 	unsigned int rd_index;
75 	unsigned int wr_index;
76 	unsigned int block_count;
77 	unsigned char last_blocknum;
78 	wait_queue_head_t read_queue;
79 	int data_available_for_read;
80 	u8 sync;
81 };
82 
83 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
84 {
85 	return container_of(sd, struct saa6588, sd);
86 }
87 
88 /* ---------------------------------------------------------------------- */
89 
90 /*
91  * SAA6588 defines
92  */
93 
94 /* Initialization and mode control byte (0w) */
95 
96 /* bit 0+1 (DAC0/DAC1) */
97 #define cModeStandard           0x00
98 #define cModeFastPI             0x01
99 #define cModeReducedRequest     0x02
100 #define cModeInvalid            0x03
101 
102 /* bit 2 (RBDS) */
103 #define cProcessingModeRDS      0x00
104 #define cProcessingModeRBDS     0x04
105 
106 /* bit 3+4 (SYM0/SYM1) */
107 #define cErrCorrectionNone      0x00
108 #define cErrCorrection2Bits     0x08
109 #define cErrCorrection5Bits     0x10
110 #define cErrCorrectionNoneRBDS  0x18
111 
112 /* bit 5 (NWSY) */
113 #define cSyncNormal             0x00
114 #define cSyncRestart            0x20
115 
116 /* bit 6 (TSQD) */
117 #define cSigQualityDetectOFF    0x00
118 #define cSigQualityDetectON     0x40
119 
120 /* bit 7 (SQCM) */
121 #define cSigQualityTriggered    0x00
122 #define cSigQualityContinous    0x80
123 
124 /* Pause level and flywheel control byte (1w) */
125 
126 /* bits 0..5 (FEB0..FEB5) */
127 #define cFlywheelMaxBlocksMask  0x3F
128 #define cFlywheelDefault        0x20
129 
130 /* bits 6+7 (PL0/PL1) */
131 #define cPauseLevel_11mV	0x00
132 #define cPauseLevel_17mV        0x40
133 #define cPauseLevel_27mV        0x80
134 #define cPauseLevel_43mV        0xC0
135 
136 /* Pause time/oscillator frequency/quality detector control byte (1w) */
137 
138 /* bits 0..4 (SQS0..SQS4) */
139 #define cQualityDetectSensMask  0x1F
140 #define cQualityDetectDefault   0x0F
141 
142 /* bit 5 (SOSC) */
143 #define cSelectOscFreqOFF	0x00
144 #define cSelectOscFreqON	0x20
145 
146 /* bit 6+7 (PTF0/PTF1) */
147 #define cOscFreq_4332kHz	0x00
148 #define cOscFreq_8664kHz	0x40
149 #define cOscFreq_12996kHz	0x80
150 #define cOscFreq_17328kHz	0xC0
151 
152 /* ---------------------------------------------------------------------- */
153 
154 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
155 {
156 	int i;
157 
158 	if (s->rd_index == s->wr_index) {
159 		if (debug > 2)
160 			dprintk(PREFIX "Read: buffer empty.\n");
161 		return 0;
162 	}
163 
164 	if (debug > 2) {
165 		dprintk(PREFIX "Read: ");
166 		for (i = s->rd_index; i < s->rd_index + 3; i++)
167 			dprintk("0x%02x ", s->buffer[i]);
168 	}
169 
170 	if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
171 		return -EFAULT;
172 
173 	s->rd_index += 3;
174 	if (s->rd_index >= s->buf_size)
175 		s->rd_index = 0;
176 	s->block_count--;
177 
178 	if (debug > 2)
179 		dprintk("%d blocks total.\n", s->block_count);
180 
181 	return 1;
182 }
183 
184 static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
185 {
186 	unsigned long flags;
187 
188 	unsigned char __user *buf_ptr = a->buffer;
189 	unsigned int i;
190 	unsigned int rd_blocks;
191 
192 	a->result = 0;
193 	if (!a->buffer)
194 		return;
195 
196 	while (!s->data_available_for_read) {
197 		int ret = wait_event_interruptible(s->read_queue,
198 					     s->data_available_for_read);
199 		if (ret == -ERESTARTSYS) {
200 			a->result = -EINTR;
201 			return;
202 		}
203 	}
204 
205 	spin_lock_irqsave(&s->lock, flags);
206 	rd_blocks = a->block_count;
207 	if (rd_blocks > s->block_count)
208 		rd_blocks = s->block_count;
209 
210 	if (!rd_blocks) {
211 		spin_unlock_irqrestore(&s->lock, flags);
212 		return;
213 	}
214 
215 	for (i = 0; i < rd_blocks; i++) {
216 		if (block_to_user_buf(s, buf_ptr)) {
217 			buf_ptr += 3;
218 			a->result++;
219 		} else
220 			break;
221 	}
222 	a->result *= 3;
223 	s->data_available_for_read = (s->block_count > 0);
224 	spin_unlock_irqrestore(&s->lock, flags);
225 }
226 
227 static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
228 {
229 	unsigned int i;
230 
231 	if (debug > 3)
232 		dprintk(PREFIX "New block: ");
233 
234 	for (i = 0; i < 3; ++i) {
235 		if (debug > 3)
236 			dprintk("0x%02x ", blockbuf[i]);
237 		s->buffer[s->wr_index] = blockbuf[i];
238 		s->wr_index++;
239 	}
240 
241 	if (s->wr_index >= s->buf_size)
242 		s->wr_index = 0;
243 
244 	if (s->wr_index == s->rd_index) {
245 		s->rd_index += 3;
246 		if (s->rd_index >= s->buf_size)
247 			s->rd_index = 0;
248 	} else
249 		s->block_count++;
250 
251 	if (debug > 3)
252 		dprintk("%d blocks total.\n", s->block_count);
253 }
254 
255 static void saa6588_i2c_poll(struct saa6588 *s)
256 {
257 	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
258 	unsigned long flags;
259 	unsigned char tmpbuf[6];
260 	unsigned char blocknum;
261 	unsigned char tmp;
262 
263 	/* Although we only need 3 bytes, we have to read at least 6.
264 	   SAA6588 returns garbage otherwise. */
265 	if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
266 		if (debug > 1)
267 			dprintk(PREFIX "read error!\n");
268 		return;
269 	}
270 
271 	s->sync = tmpbuf[0] & 0x10;
272 	if (!s->sync)
273 		return;
274 	blocknum = tmpbuf[0] >> 5;
275 	if (blocknum == s->last_blocknum) {
276 		if (debug > 3)
277 			dprintk("Saw block %d again.\n", blocknum);
278 		return;
279 	}
280 
281 	s->last_blocknum = blocknum;
282 
283 	/*
284 	   Byte order according to v4l2 specification:
285 
286 	   Byte 0: Least Significant Byte of RDS Block
287 	   Byte 1: Most Significant Byte of RDS Block
288 	   Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
289 	   occurred during reception of this block.
290 	   Bit 6: Corrected bit. Indicates that an error was
291 	   corrected for this data block.
292 	   Bits 5-3: Same as bits 0-2.
293 	   Bits 2-0: Block number.
294 
295 	   SAA6588 byte order is Status-MSB-LSB, so we have to swap the
296 	   first and the last of the 3 bytes block.
297 	 */
298 
299 	tmp = tmpbuf[2];
300 	tmpbuf[2] = tmpbuf[0];
301 	tmpbuf[0] = tmp;
302 
303 	/* Map 'Invalid block E' to 'Invalid Block' */
304 	if (blocknum == 6)
305 		blocknum = V4L2_RDS_BLOCK_INVALID;
306 	/* And if are not in mmbs mode, then 'Block E' is also mapped
307 	   to 'Invalid Block'. As far as I can tell MMBS is discontinued,
308 	   and if there is ever a need to support E blocks, then please
309 	   contact the linux-media mailinglist. */
310 	else if (!mmbs && blocknum == 5)
311 		blocknum = V4L2_RDS_BLOCK_INVALID;
312 	tmp = blocknum;
313 	tmp |= blocknum << 3;	/* Received offset == Offset Name (OK ?) */
314 	if ((tmpbuf[2] & 0x03) == 0x03)
315 		tmp |= V4L2_RDS_BLOCK_ERROR;	 /* uncorrectable error */
316 	else if ((tmpbuf[2] & 0x03) != 0x00)
317 		tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
318 	tmpbuf[2] = tmp;	/* Is this enough ? Should we also check other bits ? */
319 
320 	spin_lock_irqsave(&s->lock, flags);
321 	block_to_buf(s, tmpbuf);
322 	spin_unlock_irqrestore(&s->lock, flags);
323 	s->data_available_for_read = 1;
324 	wake_up_interruptible(&s->read_queue);
325 }
326 
327 static void saa6588_work(struct work_struct *work)
328 {
329 	struct saa6588 *s = container_of(work, struct saa6588, work.work);
330 
331 	saa6588_i2c_poll(s);
332 	schedule_delayed_work(&s->work, msecs_to_jiffies(20));
333 }
334 
335 static void saa6588_configure(struct saa6588 *s)
336 {
337 	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
338 	unsigned char buf[3];
339 	int rc;
340 
341 	buf[0] = cSyncRestart;
342 	if (mmbs)
343 		buf[0] |= cProcessingModeRBDS;
344 
345 	buf[1] = cFlywheelDefault;
346 	switch (plvl) {
347 	case 0:
348 		buf[1] |= cPauseLevel_11mV;
349 		break;
350 	case 1:
351 		buf[1] |= cPauseLevel_17mV;
352 		break;
353 	case 2:
354 		buf[1] |= cPauseLevel_27mV;
355 		break;
356 	case 3:
357 		buf[1] |= cPauseLevel_43mV;
358 		break;
359 	default:		/* nothing */
360 		break;
361 	}
362 
363 	buf[2] = cQualityDetectDefault | cSelectOscFreqON;
364 
365 	switch (xtal) {
366 	case 0:
367 		buf[2] |= cOscFreq_4332kHz;
368 		break;
369 	case 1:
370 		buf[2] |= cOscFreq_8664kHz;
371 		break;
372 	case 2:
373 		buf[2] |= cOscFreq_12996kHz;
374 		break;
375 	case 3:
376 		buf[2] |= cOscFreq_17328kHz;
377 		break;
378 	default:		/* nothing */
379 		break;
380 	}
381 
382 	dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
383 		buf[0], buf[1], buf[2]);
384 
385 	rc = i2c_master_send(client, buf, 3);
386 	if (rc != 3)
387 		printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
388 }
389 
390 /* ---------------------------------------------------------------------- */
391 
392 static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
393 {
394 	struct saa6588 *s = to_saa6588(sd);
395 	struct saa6588_command *a = arg;
396 
397 	switch (cmd) {
398 		/* --- open() for /dev/radio --- */
399 	case SAA6588_CMD_OPEN:
400 		a->result = 0;	/* return error if chip doesn't work ??? */
401 		break;
402 		/* --- close() for /dev/radio --- */
403 	case SAA6588_CMD_CLOSE:
404 		s->data_available_for_read = 1;
405 		wake_up_interruptible(&s->read_queue);
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 |= POLLIN | POLLRDNORM;
417 		}
418 		poll_wait(a->instance, &s->read_queue, a->event_list);
419 		break;
420 
421 	default:
422 		/* nothing */
423 		return -ENOIOCTLCMD;
424 	}
425 	return 0;
426 }
427 
428 static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
429 {
430 	struct saa6588 *s = to_saa6588(sd);
431 
432 	vt->capability |= V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO;
433 	if (s->sync)
434 		vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
435 	return 0;
436 }
437 
438 static int saa6588_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
439 {
440 	struct saa6588 *s = to_saa6588(sd);
441 
442 	saa6588_configure(s);
443 	return 0;
444 }
445 
446 static int saa6588_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
447 {
448 	struct i2c_client *client = v4l2_get_subdevdata(sd);
449 
450 	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_SAA6588, 0);
451 }
452 
453 /* ----------------------------------------------------------------------- */
454 
455 static const struct v4l2_subdev_core_ops saa6588_core_ops = {
456 	.g_chip_ident = saa6588_g_chip_ident,
457 	.ioctl = saa6588_ioctl,
458 };
459 
460 static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
461 	.g_tuner = saa6588_g_tuner,
462 	.s_tuner = saa6588_s_tuner,
463 };
464 
465 static const struct v4l2_subdev_ops saa6588_ops = {
466 	.core = &saa6588_core_ops,
467 	.tuner = &saa6588_tuner_ops,
468 };
469 
470 /* ---------------------------------------------------------------------- */
471 
472 static int saa6588_probe(struct i2c_client *client,
473 			 const struct i2c_device_id *id)
474 {
475 	struct saa6588 *s;
476 	struct v4l2_subdev *sd;
477 
478 	v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
479 			client->addr << 1, client->adapter->name);
480 
481 	s = kzalloc(sizeof(*s), GFP_KERNEL);
482 	if (s == NULL)
483 		return -ENOMEM;
484 
485 	s->buf_size = bufblocks * 3;
486 
487 	s->buffer = kmalloc(s->buf_size, GFP_KERNEL);
488 	if (s->buffer == NULL) {
489 		kfree(s);
490 		return -ENOMEM;
491 	}
492 	sd = &s->sd;
493 	v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
494 	spin_lock_init(&s->lock);
495 	s->block_count = 0;
496 	s->wr_index = 0;
497 	s->rd_index = 0;
498 	s->last_blocknum = 0xff;
499 	init_waitqueue_head(&s->read_queue);
500 	s->data_available_for_read = 0;
501 
502 	saa6588_configure(s);
503 
504 	/* start polling via eventd */
505 	INIT_DELAYED_WORK(&s->work, saa6588_work);
506 	schedule_delayed_work(&s->work, 0);
507 	return 0;
508 }
509 
510 static int saa6588_remove(struct i2c_client *client)
511 {
512 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
513 	struct saa6588 *s = to_saa6588(sd);
514 
515 	v4l2_device_unregister_subdev(sd);
516 
517 	cancel_delayed_work_sync(&s->work);
518 
519 	kfree(s->buffer);
520 	kfree(s);
521 	return 0;
522 }
523 
524 /* ----------------------------------------------------------------------- */
525 
526 static const struct i2c_device_id saa6588_id[] = {
527 	{ "saa6588", 0 },
528 	{ }
529 };
530 MODULE_DEVICE_TABLE(i2c, saa6588_id);
531 
532 static struct i2c_driver saa6588_driver = {
533 	.driver = {
534 		.owner	= THIS_MODULE,
535 		.name	= "saa6588",
536 	},
537 	.probe		= saa6588_probe,
538 	.remove		= saa6588_remove,
539 	.id_table	= saa6588_id,
540 };
541 
542 module_i2c_driver(saa6588_driver);
543