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 */
40static unsigned int debug;
41static unsigned int xtal;
42static unsigned int mmbs;
43static unsigned int plvl;
44static unsigned int bufblocks = 100;
45
46module_param(debug, int, 0644);
47MODULE_PARM_DESC(debug, "enable debug messages");
48module_param(xtal, int, 0);
49MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
50module_param(mmbs, int, 0);
51MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
52module_param(plvl, int, 0);
53MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
54module_param(bufblocks, int, 0);
55MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
56
57MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
58MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
59
60MODULE_LICENSE("GPL");
61
62/* ---------------------------------------------------------------------- */
63
64#define UNSET       (-1U)
65#define PREFIX      "saa6588: "
66#define dprintk     if (debug) printk
67
68struct 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
83static 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
154static 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
184static 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
227static 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
255static 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
327static 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
335static 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
392static 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
428static 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
438static 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
446static 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
455static const struct v4l2_subdev_core_ops saa6588_core_ops = {
456	.g_chip_ident = saa6588_g_chip_ident,
457	.ioctl = saa6588_ioctl,
458};
459
460static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
461	.g_tuner = saa6588_g_tuner,
462	.s_tuner = saa6588_s_tuner,
463};
464
465static const struct v4l2_subdev_ops saa6588_ops = {
466	.core = &saa6588_core_ops,
467	.tuner = &saa6588_tuner_ops,
468};
469
470/* ---------------------------------------------------------------------- */
471
472static 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
510static 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
526static const struct i2c_device_id saa6588_id[] = {
527	{ "saa6588", 0 },
528	{ }
529};
530MODULE_DEVICE_TABLE(i2c, saa6588_id);
531
532static 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
542module_i2c_driver(saa6588_driver);
543