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 */
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_param(debug, int, 0644);
54MODULE_PARM_DESC(debug, "enable debug messages");
55module_param(xtal, int, 0);
56MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
57module_param(rbds, int, 0);
58MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
59module_param(plvl, int, 0);
60MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
61module_param(bufblocks, int, 0);
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		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
232static 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
260static 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
320static void saa6588_timer(unsigned long data)
321{
322	struct saa6588 *s = (struct saa6588 *)data;
323
324	schedule_work(&s->work);
325}
326
327static 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
335static 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
392static 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	s->client = client_template;
410	s->block_count = 0;
411	s->wr_index = 0;
412	s->rd_index = 0;
413	s->last_blocknum = 0xff;
414	init_waitqueue_head(&s->read_queue);
415	s->data_available_for_read = 0;
416	i2c_set_clientdata(&s->client, s);
417	i2c_attach_client(&s->client);
418
419	saa6588_configure(s);
420
421	/* start polling via eventd */
422	INIT_WORK(&s->work, saa6588_work);
423	init_timer(&s->timer);
424	s->timer.function = saa6588_timer;
425	s->timer.data = (unsigned long)s;
426	schedule_work(&s->work);
427	return 0;
428}
429
430static int saa6588_probe(struct i2c_adapter *adap)
431{
432	if (adap->class & I2C_CLASS_TV_ANALOG)
433		return i2c_probe(adap, &addr_data, saa6588_attach);
434	return 0;
435}
436
437static int saa6588_detach(struct i2c_client *client)
438{
439	struct saa6588 *s = i2c_get_clientdata(client);
440
441	del_timer_sync(&s->timer);
442	flush_scheduled_work();
443
444	i2c_detach_client(client);
445	kfree(s->buffer);
446	kfree(s);
447	return 0;
448}
449
450static int saa6588_command(struct i2c_client *client, unsigned int cmd,
451							void *arg)
452{
453	struct saa6588 *s = i2c_get_clientdata(client);
454	struct rds_command *a = (struct rds_command *)arg;
455
456	switch (cmd) {
457		/* --- open() for /dev/radio --- */
458	case RDS_CMD_OPEN:
459		a->result = 0;	/* return error if chip doesn't work ??? */
460		break;
461		/* --- close() for /dev/radio --- */
462	case RDS_CMD_CLOSE:
463		s->data_available_for_read = 1;
464		wake_up_interruptible(&s->read_queue);
465		a->result = 0;
466		break;
467		/* --- read() for /dev/radio --- */
468	case RDS_CMD_READ:
469		read_from_buf(s, a);
470		break;
471		/* --- poll() for /dev/radio --- */
472	case RDS_CMD_POLL:
473		a->result = 0;
474		if (s->data_available_for_read) {
475			a->result |= POLLIN | POLLRDNORM;
476		}
477		poll_wait(a->instance, &s->read_queue, a->event_list);
478		break;
479
480	default:
481		/* nothing */
482		break;
483	}
484	return 0;
485}
486
487/* ----------------------------------------------------------------------- */
488
489static struct i2c_driver driver = {
490	.driver = {
491		.name = "saa6588",
492	},
493	.id = -1,
494	.attach_adapter = saa6588_probe,
495	.detach_client = saa6588_detach,
496	.command = saa6588_command,
497};
498
499static struct i2c_client client_template = {
500	.name = "saa6588",
501	.driver = &driver,
502};
503
504static int __init saa6588_init_module(void)
505{
506	return i2c_add_driver(&driver);
507}
508
509static void __exit saa6588_cleanup_module(void)
510{
511	i2c_del_driver(&driver);
512}
513
514module_init(saa6588_init_module);
515module_exit(saa6588_cleanup_module);
516
517/*
518 * Overrides for Emacs so that we follow Linus's tabbing style.
519 * ---------------------------------------------------------------------------
520 * Local variables:
521 * c-basic-offset: 8
522 * End:
523 */
524