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/videodev.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
35 #include <media/rds.h>
36
37 /* Addresses to scan */
38 static unsigned short normal_i2c[] = {
39 0x20 >> 1,
40 0x22 >> 1,
41 I2C_CLIENT_END,
42 };
43
44 I2C_CLIENT_INSMOD;
45
46 /* insmod options */
47 static unsigned int debug = 0;
48 static unsigned int xtal = 0;
49 static unsigned int rbds = 0;
50 static unsigned int plvl = 0;
51 static unsigned int bufblocks = 100;
52
53 module_param(debug, int, 0644);
54 MODULE_PARM_DESC(debug, "enable debug messages");
55 module_param(xtal, int, 0);
56 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
57 module_param(rbds, int, 0);
58 MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
59 module_param(plvl, int, 0);
60 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
61 module_param(bufblocks, int, 0);
62 MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
63
64 MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
65 MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
66
67 MODULE_LICENSE("GPL");
68
69 /* ---------------------------------------------------------------------- */
70
71 #define UNSET (-1U)
72 #define PREFIX "saa6588: "
73 #define dprintk if (debug) printk
74
75 struct saa6588 {
76 struct i2c_client client;
77 struct work_struct work;
78 struct timer_list timer;
79 spinlock_t lock;
80 unsigned char *buffer;
81 unsigned int buf_size;
82 unsigned int rd_index;
83 unsigned int wr_index;
84 unsigned int block_count;
85 unsigned char last_blocknum;
86 wait_queue_head_t read_queue;
87 int data_available_for_read;
88 };
89
90 static struct i2c_driver driver;
91 static struct i2c_client client_template;
92
93 /* ---------------------------------------------------------------------- */
94
95 /*
96 * SAA6588 defines
97 */
98
99 /* Initialization and mode control byte (0w) */
100
101 /* bit 0+1 (DAC0/DAC1) */
102 #define cModeStandard 0x00
103 #define cModeFastPI 0x01
104 #define cModeReducedRequest 0x02
105 #define cModeInvalid 0x03
106
107 /* bit 2 (RBDS) */
108 #define cProcessingModeRDS 0x00
109 #define cProcessingModeRBDS 0x04
110
111 /* bit 3+4 (SYM0/SYM1) */
112 #define cErrCorrectionNone 0x00
113 #define cErrCorrection2Bits 0x08
114 #define cErrCorrection5Bits 0x10
115 #define cErrCorrectionNoneRBDS 0x18
116
117 /* bit 5 (NWSY) */
118 #define cSyncNormal 0x00
119 #define cSyncRestart 0x20
120
121 /* bit 6 (TSQD) */
122 #define cSigQualityDetectOFF 0x00
123 #define cSigQualityDetectON 0x40
124
125 /* bit 7 (SQCM) */
126 #define cSigQualityTriggered 0x00
127 #define cSigQualityContinous 0x80
128
129 /* Pause level and flywheel control byte (1w) */
130
131 /* bits 0..5 (FEB0..FEB5) */
132 #define cFlywheelMaxBlocksMask 0x3F
133 #define cFlywheelDefault 0x20
134
135 /* bits 6+7 (PL0/PL1) */
136 #define cPauseLevel_11mV 0x00
137 #define cPauseLevel_17mV 0x40
138 #define cPauseLevel_27mV 0x80
139 #define cPauseLevel_43mV 0xC0
140
141 /* Pause time/oscillator frequency/quality detector control byte (1w) */
142
143 /* bits 0..4 (SQS0..SQS4) */
144 #define cQualityDetectSensMask 0x1F
145 #define cQualityDetectDefault 0x0F
146
147 /* bit 5 (SOSC) */
148 #define cSelectOscFreqOFF 0x00
149 #define cSelectOscFreqON 0x20
150
151 /* bit 6+7 (PTF0/PTF1) */
152 #define cOscFreq_4332kHz 0x00
153 #define cOscFreq_8664kHz 0x40
154 #define cOscFreq_12996kHz 0x80
155 #define cOscFreq_17328kHz 0xC0
156
157 /* ---------------------------------------------------------------------- */
158
159 static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
160 {
161 int i;
162
163 if (s->rd_index == s->wr_index) {
164 if (debug > 2)
165 dprintk(PREFIX "Read: buffer empty.\n");
166 return 0;
167 }
168
169 if (debug > 2) {
170 dprintk(PREFIX "Read: ");
171 for (i = s->rd_index; i < s->rd_index + 3; i++)
172 dprintk("0x%02x ", s->buffer[i]);
173 }
174
175 if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
176 return -EFAULT;
177
178 s->rd_index += 3;
179 if (s->rd_index >= s->buf_size)
180 s->rd_index = 0;
181 s->block_count--;
182
183 if (debug > 2)
184 dprintk("%d blocks total.\n", s->block_count);
185
186 return 1;
187 }
188
189 static void read_from_buf(struct saa6588 *s, struct rds_command *a)
190 {
191 unsigned long flags;
192
193 unsigned char __user *buf_ptr = a->buffer;
194 unsigned int i;
195 unsigned int rd_blocks;
196
197 a->result = 0;
198 if (!a->buffer)
199 return;
200
201 while (!s->data_available_for_read) {
202 int ret = wait_event_interruptible(s->read_queue,
203 s->data_available_for_read);
204 if (ret == -ERESTARTSYS) {
205 a->result = -EINTR;
206 return;
207 }
208 }
209
210 spin_lock_irqsave(&s->lock, flags);
211 rd_blocks = a->block_count;
212 if (rd_blocks > s->block_count)
213 rd_blocks = s->block_count;
214
215 if (!rd_blocks) {
216 spin_unlock_irqrestore(&s->lock, flags);
217 return;
218 }
219
220 for (i = 0; i < rd_blocks; i++) {
221 if (block_to_user_buf(s, buf_ptr)) {
222 buf_ptr += 3;
223 a->result++;
224 } else
225 break;
226 }
227 a->result *= 3;
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 unsigned long flags;
263 unsigned char tmpbuf[6];
264 unsigned char blocknum;
265 unsigned char tmp;
266
267 /* Although we only need 3 bytes, we have to read at least 6.
268 SAA6588 returns garbage otherwise */
269 if (6 != i2c_master_recv(&s->client, &tmpbuf[0], 6)) {
270 if (debug > 1)
271 dprintk(PREFIX "read error!\n");
272 return;
273 }
274
275 blocknum = tmpbuf[0] >> 5;
276 if (blocknum == s->last_blocknum) {
277 if (debug > 3)
278 dprintk("Saw block %d again.\n", blocknum);
279 return;
280 }
281
282 s->last_blocknum = blocknum;
283
284 /*
285 Byte order according to v4l2 specification:
286
287 Byte 0: Least Significant Byte of RDS Block
288 Byte 1: Most Significant Byte of RDS Block
289 Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
290 occurred during reception of this block.
291 Bit 6: Corrected bit. Indicates that an error was
292 corrected for this data block.
293 Bits 5-3: Received Offset. Indicates the offset received
294 by the sync system.
295 Bits 2-0: Offset Name. Indicates the offset applied to this data.
296
297 SAA6588 byte order is Status-MSB-LSB, so we have to swap the
298 first and the last of the 3 bytes block.
299 */
300
301 tmp = tmpbuf[2];
302 tmpbuf[2] = tmpbuf[0];
303 tmpbuf[0] = tmp;
304
305 tmp = blocknum;
306 tmp |= blocknum << 3; /* Received offset == Offset Name (OK ?) */
307 if ((tmpbuf[2] & 0x03) == 0x03)
308 tmp |= 0x80; /* uncorrectable error */
309 else if ((tmpbuf[2] & 0x03) != 0x00)
310 tmp |= 0x40; /* corrected error */
311 tmpbuf[2] = tmp; /* Is this enough ? Should we also check other bits ? */
312
313 spin_lock_irqsave(&s->lock, flags);
314 block_to_buf(s, tmpbuf);
315 spin_unlock_irqrestore(&s->lock, flags);
316 s->data_available_for_read = 1;
317 wake_up_interruptible(&s->read_queue);
318 }
319
320 static void saa6588_timer(unsigned long data)
321 {
322 struct saa6588 *s = (struct saa6588 *)data;
323
324 schedule_work(&s->work);
325 }
326
327 static void saa6588_work(struct work_struct *work)
328 {
329 struct saa6588 *s = container_of(work, struct saa6588, work);
330
331 saa6588_i2c_poll(s);
332 mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
333 }
334
335 static int saa6588_configure(struct saa6588 *s)
336 {
337 unsigned char buf[3];
338 int rc;
339
340 buf[0] = cSyncRestart;
341 if (rbds)
342 buf[0] |= cProcessingModeRBDS;
343
344 buf[1] = cFlywheelDefault;
345 switch (plvl) {
346 case 0:
347 buf[1] |= cPauseLevel_11mV;
348 break;
349 case 1:
350 buf[1] |= cPauseLevel_17mV;
351 break;
352 case 2:
353 buf[1] |= cPauseLevel_27mV;
354 break;
355 case 3:
356 buf[1] |= cPauseLevel_43mV;
357 break;
358 default: /* nothing */
359 break;
360 }
361
362 buf[2] = cQualityDetectDefault | cSelectOscFreqON;
363
364 switch (xtal) {
365 case 0:
366 buf[2] |= cOscFreq_4332kHz;
367 break;
368 case 1:
369 buf[2] |= cOscFreq_8664kHz;
370 break;
371 case 2:
372 buf[2] |= cOscFreq_12996kHz;
373 break;
374 case 3:
375 buf[2] |= cOscFreq_17328kHz;
376 break;
377 default: /* nothing */
378 break;
379 }
380
381 dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
382 buf[0], buf[1], buf[2]);
383
384 if (3 != (rc = i2c_master_send(&s->client, buf, 3)))
385 printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
386
387 return 0;
388 }
389
390 /* ---------------------------------------------------------------------- */
391
392 static int saa6588_attach(struct i2c_adapter *adap, int addr, int kind)
393 {
394 struct saa6588 *s;
395 client_template.adapter = adap;
396 client_template.addr = addr;
397
398 printk(PREFIX "chip found @ 0x%x\n", addr << 1);
399
400 if (NULL == (s = kmalloc(sizeof(*s), GFP_KERNEL)))
401 return -ENOMEM;
402
403 s->buf_size = bufblocks * 3;
404
405 if (NULL == (s->buffer = kmalloc(s->buf_size, GFP_KERNEL))) {
406 kfree(s);
407 return -ENOMEM;
408 }
409 spin_lock_init(&s->lock);
410 s->client = client_template;
411 s->block_count = 0;
412 s->wr_index = 0;
413 s->rd_index = 0;
414 s->last_blocknum = 0xff;
415 init_waitqueue_head(&s->read_queue);
416 s->data_available_for_read = 0;
417 i2c_set_clientdata(&s->client, s);
418 i2c_attach_client(&s->client);
419
420 saa6588_configure(s);
421
422 /* start polling via eventd */
423 INIT_WORK(&s->work, saa6588_work);
424 init_timer(&s->timer);
425 s->timer.function = saa6588_timer;
426 s->timer.data = (unsigned long)s;
427 schedule_work(&s->work);
428 return 0;
429 }
430
431 static int saa6588_probe(struct i2c_adapter *adap)
432 {
433 if (adap->class & I2C_CLASS_TV_ANALOG)
434 return i2c_probe(adap, &addr_data, saa6588_attach);
435 return 0;
436 }
437
438 static int saa6588_detach(struct i2c_client *client)
439 {
440 struct saa6588 *s = i2c_get_clientdata(client);
441
442 del_timer_sync(&s->timer);
443 flush_scheduled_work();
444
445 i2c_detach_client(client);
446 kfree(s->buffer);
447 kfree(s);
448 return 0;
449 }
450
451 static int saa6588_command(struct i2c_client *client, unsigned int cmd,
452 void *arg)
453 {
454 struct saa6588 *s = i2c_get_clientdata(client);
455 struct rds_command *a = (struct rds_command *)arg;
456
457 switch (cmd) {
458 /* --- open() for /dev/radio --- */
459 case RDS_CMD_OPEN:
460 a->result = 0; /* return error if chip doesn't work ??? */
461 break;
462 /* --- close() for /dev/radio --- */
463 case RDS_CMD_CLOSE:
464 s->data_available_for_read = 1;
465 wake_up_interruptible(&s->read_queue);
466 a->result = 0;
467 break;
468 /* --- read() for /dev/radio --- */
469 case RDS_CMD_READ:
470 read_from_buf(s, a);
471 break;
472 /* --- poll() for /dev/radio --- */
473 case RDS_CMD_POLL:
474 a->result = 0;
475 if (s->data_available_for_read) {
476 a->result |= POLLIN | POLLRDNORM;
477 }
478 poll_wait(a->instance, &s->read_queue, a->event_list);
479 break;
480
481 default:
482 /* nothing */
483 break;
484 }
485 return 0;
486 }
487
488 /* ----------------------------------------------------------------------- */
489
490 static struct i2c_driver driver = {
491 .driver = {
492 .name = "saa6588",
493 },
494 .id = -1, /* FIXME */
495 .attach_adapter = saa6588_probe,
496 .detach_client = saa6588_detach,
497 .command = saa6588_command,
498 };
499
500 static struct i2c_client client_template = {
501 .name = "saa6588",
502 .driver = &driver,
503 };
504
505 static int __init saa6588_init_module(void)
506 {
507 return i2c_add_driver(&driver);
508 }
509
510 static void __exit saa6588_cleanup_module(void)
511 {
512 i2c_del_driver(&driver);
513 }
514
515 module_init(saa6588_init_module);
516 module_exit(saa6588_cleanup_module);
517
518 /*
519 * Overrides for Emacs so that we follow Linus's tabbing style.
520 * ---------------------------------------------------------------------------
521 * Local variables:
522 * c-basic-offset: 8
523 * End:
524 */
525
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