saa6588.c revision 6c3d67abdb79ff3e22cd19476c05294274434143 
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 "rds.h"
36
37/* Addresses to scan */
38static unsigned short normal_i2c[] = {
39	0x20 >> 1,
40	0x22 >> 1,
41	I2C_CLIENT_END,
42};
43
44I2C_CLIENT_INSMOD;
45
46/* insmod options */
47static unsigned int debug = 0;
48static unsigned int xtal = 0;
49static unsigned int rbds = 0;
50static unsigned int plvl = 0;
51static unsigned int bufblocks = 100;
52
53MODULE_PARM(debug, "i");
54MODULE_PARM_DESC(debug, "enable debug messages");
55MODULE_PARM(xtal, "i");
56MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
57MODULE_PARM(rbds, "i");
58MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
59MODULE_PARM(plvl, "i");
60MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
61MODULE_PARM(bufblocks, "i");
62MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
63
64MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
65MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
66
67MODULE_LICENSE("GPL");
68
69/* ---------------------------------------------------------------------- */
70
71#define UNSET       (-1U)
72#define PREFIX      "saa6588: "
73#define dprintk     if (debug) printk
74
75struct 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
90static struct i2c_driver driver;
91static 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
159static 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
189static 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		return;
217
218	for (i = 0; i < rd_blocks; i++) {
219		if (block_to_user_buf(s, buf_ptr)) {
220			buf_ptr += 3;
221			a->result++;
222		} else
223			break;
224	}
225	a->result *= 3;
226	s->data_available_for_read = (s->block_count > 0);
227	spin_unlock_irqrestore(&s->lock, flags);
228}
229
230static void block_to_buf(struct saa6588 *s, unsigned char *blockbuf)
231{
232	unsigned int i;
233
234	if (debug > 3)
235		dprintk(PREFIX "New block: ");
236
237	for (i = 0; i < 3; ++i) {
238		if (debug > 3)
239			dprintk("0x%02x ", blockbuf[i]);
240		s->buffer[s->wr_index] = blockbuf[i];
241		s->wr_index++;
242	}
243
244	if (s->wr_index >= s->buf_size)
245		s->wr_index = 0;
246
247	if (s->wr_index == s->rd_index) {
248		s->rd_index += 3;
249		if (s->rd_index >= s->buf_size)
250			s->rd_index = 0;
251	} else
252		s->block_count++;
253
254	if (debug > 3)
255		dprintk("%d blocks total.\n", s->block_count);
256}
257
258static void saa6588_i2c_poll(struct saa6588 *s)
259{
260	unsigned long flags;
261	unsigned char tmpbuf[6];
262	unsigned char blocknum;
263	unsigned char tmp;
264
265	/* Although we only need 3 bytes, we have to read at least 6.
266	   SAA6588 returns garbage otherwise */
267	if (6 != i2c_master_recv(&s->client, &tmpbuf[0], 6)) {
268		if (debug > 1)
269			dprintk(PREFIX "read error!\n");
270		return;
271	}
272
273	blocknum = tmpbuf[0] >> 5;
274	if (blocknum == s->last_blocknum) {
275		if (debug > 3)
276			dprintk("Saw block %d again.\n", blocknum);
277		return;
278	}
279
280	s->last_blocknum = blocknum;
281
282	/*
283	   Byte order according to v4l2 specification:
284
285	   Byte 0: Least Significant Byte of RDS Block
286	   Byte 1: Most Significant Byte of RDS Block
287	   Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
288	   occurred during reception of this block.
289	   Bit 6: Corrected bit. Indicates that an error was
290	   corrected for this data block.
291	   Bits 5-3: Received Offset. Indicates the offset received
292	   by the sync system.
293	   Bits 2-0: Offset Name. Indicates the offset applied to this data.
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	tmp = blocknum;
304	tmp |= blocknum << 3;	/* Received offset == Offset Name (OK ?) */
305	if ((tmpbuf[2] & 0x03) == 0x03)
306		tmp |= 0x80;	/* uncorrectable error */
307	else if ((tmpbuf[2] & 0x03) != 0x00)
308		tmp |= 0x40;	/* corrected error */
309	tmpbuf[2] = tmp;	/* Is this enough ? Should we also check other bits ? */
310
311	spin_lock_irqsave(&s->lock, flags);
312	block_to_buf(s, tmpbuf);
313	spin_unlock_irqrestore(&s->lock, flags);
314	s->data_available_for_read = 1;
315	wake_up_interruptible(&s->read_queue);
316}
317
318static void saa6588_timer(unsigned long data)
319{
320	struct saa6588 *s = (struct saa6588 *)data;
321
322	schedule_work(&s->work);
323}
324
325static void saa6588_work(void *data)
326{
327	struct saa6588 *s = (struct saa6588 *)data;
328
329	saa6588_i2c_poll(s);
330	mod_timer(&s->timer, jiffies + msecs_to_jiffies(20));
331}
332
333static int saa6588_configure(struct saa6588 *s)
334{
335	unsigned char buf[3];
336	int rc;
337
338	buf[0] = cSyncRestart;
339	if (rbds)
340		buf[0] |= cProcessingModeRBDS;
341
342	buf[1] = cFlywheelDefault;
343	switch (plvl) {
344	case 0:
345		buf[1] |= cPauseLevel_11mV;
346		break;
347	case 1:
348		buf[1] |= cPauseLevel_17mV;
349		break;
350	case 2:
351		buf[1] |= cPauseLevel_27mV;
352		break;
353	case 3:
354		buf[1] |= cPauseLevel_43mV;
355		break;
356	default:		/* nothing */
357		break;
358	}
359
360	buf[2] = cQualityDetectDefault | cSelectOscFreqON;
361
362	switch (xtal) {
363	case 0:
364		buf[2] |= cOscFreq_4332kHz;
365		break;
366	case 1:
367		buf[2] |= cOscFreq_8664kHz;
368		break;
369	case 2:
370		buf[2] |= cOscFreq_12996kHz;
371		break;
372	case 3:
373		buf[2] |= cOscFreq_17328kHz;
374		break;
375	default:		/* nothing */
376		break;
377	}
378
379	dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
380		buf[0], buf[1], buf[2]);
381
382	if (3 != (rc = i2c_master_send(&s->client, buf, 3)))
383		printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
384
385	return 0;
386}
387
388/* ---------------------------------------------------------------------- */
389
390static int saa6588_attach(struct i2c_adapter *adap, int addr, int kind)
391{
392	struct saa6588 *s;
393	client_template.adapter = adap;
394	client_template.addr = addr;
395
396	printk(PREFIX "chip found @ 0x%x\n", addr << 1);
397
398	if (NULL == (s = kmalloc(sizeof(*s), GFP_KERNEL)))
399		return -ENOMEM;
400
401	s->buf_size = bufblocks * 3;
402
403	if (NULL == (s->buffer = kmalloc(s->buf_size, GFP_KERNEL))) {
404		kfree(s);
405		return -ENOMEM;
406	}
407	s->client = client_template;
408	s->block_count = 0;
409	s->wr_index = 0;
410	s->rd_index = 0;
411	s->last_blocknum = 0xff;
412	init_waitqueue_head(&s->read_queue);
413	s->data_available_for_read = 0;
414	i2c_set_clientdata(&s->client, s);
415	i2c_attach_client(&s->client);
416
417	saa6588_configure(s);
418
419	/* start polling via eventd */
420	INIT_WORK(&s->work, saa6588_work, s);
421	init_timer(&s->timer);
422	s->timer.function = saa6588_timer;
423	s->timer.data = (unsigned long)s;
424	schedule_work(&s->work);
425
426	return 0;
427}
428
429static int saa6588_probe(struct i2c_adapter *adap)
430{
431#ifdef I2C_CLASS_TV_ANALOG
432	if (adap->class & I2C_CLASS_TV_ANALOG)
433		return i2c_probe(adap, &addr_data, saa6588_attach);
434#else
435	switch (adap->id) {
436	case I2C_HW_B_BT848:
437	case I2C_HW_B_RIVA:
438	case I2C_HW_SAA7134:
439		return i2c_probe(adap, &addr_data, saa6588_attach);
440		break;
441	}
442#endif
443	return 0;
444}
445
446static int saa6588_detach(struct i2c_client *client)
447{
448	struct saa6588 *s = i2c_get_clientdata(client);
449
450	del_timer_sync(&s->timer);
451	flush_scheduled_work();
452
453	i2c_detach_client(client);
454	kfree(s->buffer);
455	kfree(s);
456	return 0;
457}
458
459static int saa6588_command(struct i2c_client *client, unsigned int cmd,
460							void *arg)
461{
462	struct saa6588 *s = i2c_get_clientdata(client);
463	struct rds_command *a = (struct rds_command *)arg;
464
465	switch (cmd) {
466		/* --- open() for /dev/radio --- */
467	case RDS_CMD_OPEN:
468		a->result = 0;	/* return error if chip doesn't work ??? */
469		break;
470		/* --- close() for /dev/radio --- */
471	case RDS_CMD_CLOSE:
472		s->data_available_for_read = 1;
473		wake_up_interruptible(&s->read_queue);
474		a->result = 0;
475		break;
476		/* --- read() for /dev/radio --- */
477	case RDS_CMD_READ:
478		read_from_buf(s, a);
479		break;
480		/* --- poll() for /dev/radio --- */
481	case RDS_CMD_POLL:
482		a->result = 0;
483		if (s->data_available_for_read) {
484			a->result |= POLLIN | POLLRDNORM;
485		}
486		poll_wait(a->instance, &s->read_queue, a->event_list);
487		break;
488
489	default:
490		/* nothing */
491		break;
492	}
493	return 0;
494}
495
496/* ----------------------------------------------------------------------- */
497
498static struct i2c_driver driver = {
499	.owner = THIS_MODULE,
500	.name = "i2c saa6588 driver",
501	.id = -1,		/* FIXME */
502	.flags = I2C_DF_NOTIFY,
503	.attach_adapter = saa6588_probe,
504	.detach_client = saa6588_detach,
505	.command = saa6588_command,
506};
507
508static struct i2c_client client_template = {
509	.name = "saa6588",
510	.flags = I2C_CLIENT_ALLOW_USE,
511	.driver = &driver,
512};
513
514static int __init saa6588_init_module(void)
515{
516	return i2c_add_driver(&driver);
517}
518
519static void __exit saa6588_cleanup_module(void)
520{
521	i2c_del_driver(&driver);
522}
523
524module_init(saa6588_init_module);
525module_exit(saa6588_cleanup_module);
526
527/*
528 * Overrides for Emacs so that we follow Linus's tabbing style.
529 * ---------------------------------------------------------------------------
530 * Local variables:
531 * c-basic-offset: 8
532 * End:
533 */
534