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
37
38/* insmod options */
39static unsigned int debug;
40static unsigned int xtal;
41static unsigned int mmbs;
42static unsigned int plvl;
43static unsigned int bufblocks = 100;
44
45module_param(debug, int, 0644);
46MODULE_PARM_DESC(debug, "enable debug messages");
47module_param(xtal, int, 0);
48MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
49module_param(mmbs, int, 0);
50MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
51module_param(plvl, int, 0);
52MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
53module_param(bufblocks, int, 0);
54MODULE_PARM_DESC(bufblocks, "number of buffered blocks, default 100");
55
56MODULE_DESCRIPTION("v4l2 driver module for SAA6588 RDS decoder");
57MODULE_AUTHOR("Hans J. Koch <koch@hjk-az.de>");
58
59MODULE_LICENSE("GPL");
60
61/* ---------------------------------------------------------------------- */
62
63#define UNSET       (-1U)
64#define PREFIX      "saa6588: "
65#define dprintk     if (debug) printk
66
67struct saa6588 {
68	struct v4l2_subdev sd;
69	struct delayed_work work;
70	spinlock_t lock;
71	unsigned char *buffer;
72	unsigned int buf_size;
73	unsigned int rd_index;
74	unsigned int wr_index;
75	unsigned int block_count;
76	unsigned char last_blocknum;
77	wait_queue_head_t read_queue;
78	int data_available_for_read;
79	u8 sync;
80};
81
82static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
83{
84	return container_of(sd, struct saa6588, sd);
85}
86
87/* ---------------------------------------------------------------------- */
88
89/*
90 * SAA6588 defines
91 */
92
93/* Initialization and mode control byte (0w) */
94
95/* bit 0+1 (DAC0/DAC1) */
96#define cModeStandard           0x00
97#define cModeFastPI             0x01
98#define cModeReducedRequest     0x02
99#define cModeInvalid            0x03
100
101/* bit 2 (RBDS) */
102#define cProcessingModeRDS      0x00
103#define cProcessingModeRBDS     0x04
104
105/* bit 3+4 (SYM0/SYM1) */
106#define cErrCorrectionNone      0x00
107#define cErrCorrection2Bits     0x08
108#define cErrCorrection5Bits     0x10
109#define cErrCorrectionNoneRBDS  0x18
110
111/* bit 5 (NWSY) */
112#define cSyncNormal             0x00
113#define cSyncRestart            0x20
114
115/* bit 6 (TSQD) */
116#define cSigQualityDetectOFF    0x00
117#define cSigQualityDetectON     0x40
118
119/* bit 7 (SQCM) */
120#define cSigQualityTriggered    0x00
121#define cSigQualityContinous    0x80
122
123/* Pause level and flywheel control byte (1w) */
124
125/* bits 0..5 (FEB0..FEB5) */
126#define cFlywheelMaxBlocksMask  0x3F
127#define cFlywheelDefault        0x20
128
129/* bits 6+7 (PL0/PL1) */
130#define cPauseLevel_11mV	0x00
131#define cPauseLevel_17mV        0x40
132#define cPauseLevel_27mV        0x80
133#define cPauseLevel_43mV        0xC0
134
135/* Pause time/oscillator frequency/quality detector control byte (1w) */
136
137/* bits 0..4 (SQS0..SQS4) */
138#define cQualityDetectSensMask  0x1F
139#define cQualityDetectDefault   0x0F
140
141/* bit 5 (SOSC) */
142#define cSelectOscFreqOFF	0x00
143#define cSelectOscFreqON	0x20
144
145/* bit 6+7 (PTF0/PTF1) */
146#define cOscFreq_4332kHz	0x00
147#define cOscFreq_8664kHz	0x40
148#define cOscFreq_12996kHz	0x80
149#define cOscFreq_17328kHz	0xC0
150
151/* ---------------------------------------------------------------------- */
152
153static bool block_from_buf(struct saa6588 *s, unsigned char *buf)
154{
155	int i;
156
157	if (s->rd_index == s->wr_index) {
158		if (debug > 2)
159			dprintk(PREFIX "Read: buffer empty.\n");
160		return false;
161	}
162
163	if (debug > 2) {
164		dprintk(PREFIX "Read: ");
165		for (i = s->rd_index; i < s->rd_index + 3; i++)
166			dprintk("0x%02x ", s->buffer[i]);
167	}
168
169	memcpy(buf, &s->buffer[s->rd_index], 3);
170
171	s->rd_index += 3;
172	if (s->rd_index >= s->buf_size)
173		s->rd_index = 0;
174	s->block_count--;
175
176	if (debug > 2)
177		dprintk("%d blocks total.\n", s->block_count);
178
179	return true;
180}
181
182static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
183{
184	unsigned char __user *buf_ptr = a->buffer;
185	unsigned char buf[3];
186	unsigned long flags;
187	unsigned int rd_blocks;
188	unsigned int i;
189
190	a->result = 0;
191	if (!a->buffer)
192		return;
193
194	while (!a->nonblocking && !s->data_available_for_read) {
195		int ret = wait_event_interruptible(s->read_queue,
196					     s->data_available_for_read);
197		if (ret == -ERESTARTSYS) {
198			a->result = -EINTR;
199			return;
200		}
201	}
202
203	rd_blocks = a->block_count;
204	spin_lock_irqsave(&s->lock, flags);
205	if (rd_blocks > s->block_count)
206		rd_blocks = s->block_count;
207	spin_unlock_irqrestore(&s->lock, flags);
208
209	if (!rd_blocks)
210		return;
211
212	for (i = 0; i < rd_blocks; i++) {
213		bool got_block;
214
215		spin_lock_irqsave(&s->lock, flags);
216		got_block = block_from_buf(s, buf);
217		spin_unlock_irqrestore(&s->lock, flags);
218		if (!got_block)
219			break;
220		if (copy_to_user(buf_ptr, buf, 3)) {
221			a->result = -EFAULT;
222			return;
223		}
224		buf_ptr += 3;
225		a->result += 3;
226	}
227	spin_lock_irqsave(&s->lock, flags);
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	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
263	unsigned long flags;
264	unsigned char tmpbuf[6];
265	unsigned char blocknum;
266	unsigned char tmp;
267
268	/* Although we only need 3 bytes, we have to read at least 6.
269	   SAA6588 returns garbage otherwise. */
270	if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
271		if (debug > 1)
272			dprintk(PREFIX "read error!\n");
273		return;
274	}
275
276	s->sync = tmpbuf[0] & 0x10;
277	if (!s->sync)
278		return;
279	blocknum = tmpbuf[0] >> 5;
280	if (blocknum == s->last_blocknum) {
281		if (debug > 3)
282			dprintk("Saw block %d again.\n", blocknum);
283		return;
284	}
285
286	s->last_blocknum = blocknum;
287
288	/*
289	   Byte order according to v4l2 specification:
290
291	   Byte 0: Least Significant Byte of RDS Block
292	   Byte 1: Most Significant Byte of RDS Block
293	   Byte 2 Bit 7: Error bit. Indicates that an uncorrectable error
294	   occurred during reception of this block.
295	   Bit 6: Corrected bit. Indicates that an error was
296	   corrected for this data block.
297	   Bits 5-3: Same as bits 0-2.
298	   Bits 2-0: Block number.
299
300	   SAA6588 byte order is Status-MSB-LSB, so we have to swap the
301	   first and the last of the 3 bytes block.
302	 */
303
304	tmp = tmpbuf[2];
305	tmpbuf[2] = tmpbuf[0];
306	tmpbuf[0] = tmp;
307
308	/* Map 'Invalid block E' to 'Invalid Block' */
309	if (blocknum == 6)
310		blocknum = V4L2_RDS_BLOCK_INVALID;
311	/* And if are not in mmbs mode, then 'Block E' is also mapped
312	   to 'Invalid Block'. As far as I can tell MMBS is discontinued,
313	   and if there is ever a need to support E blocks, then please
314	   contact the linux-media mailinglist. */
315	else if (!mmbs && blocknum == 5)
316		blocknum = V4L2_RDS_BLOCK_INVALID;
317	tmp = blocknum;
318	tmp |= blocknum << 3;	/* Received offset == Offset Name (OK ?) */
319	if ((tmpbuf[2] & 0x03) == 0x03)
320		tmp |= V4L2_RDS_BLOCK_ERROR;	 /* uncorrectable error */
321	else if ((tmpbuf[2] & 0x03) != 0x00)
322		tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
323	tmpbuf[2] = tmp;	/* Is this enough ? Should we also check other bits ? */
324
325	spin_lock_irqsave(&s->lock, flags);
326	block_to_buf(s, tmpbuf);
327	spin_unlock_irqrestore(&s->lock, flags);
328	s->data_available_for_read = 1;
329	wake_up_interruptible(&s->read_queue);
330}
331
332static void saa6588_work(struct work_struct *work)
333{
334	struct saa6588 *s = container_of(work, struct saa6588, work.work);
335
336	saa6588_i2c_poll(s);
337	schedule_delayed_work(&s->work, msecs_to_jiffies(20));
338}
339
340static void saa6588_configure(struct saa6588 *s)
341{
342	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
343	unsigned char buf[3];
344	int rc;
345
346	buf[0] = cSyncRestart;
347	if (mmbs)
348		buf[0] |= cProcessingModeRBDS;
349
350	buf[1] = cFlywheelDefault;
351	switch (plvl) {
352	case 0:
353		buf[1] |= cPauseLevel_11mV;
354		break;
355	case 1:
356		buf[1] |= cPauseLevel_17mV;
357		break;
358	case 2:
359		buf[1] |= cPauseLevel_27mV;
360		break;
361	case 3:
362		buf[1] |= cPauseLevel_43mV;
363		break;
364	default:		/* nothing */
365		break;
366	}
367
368	buf[2] = cQualityDetectDefault | cSelectOscFreqON;
369
370	switch (xtal) {
371	case 0:
372		buf[2] |= cOscFreq_4332kHz;
373		break;
374	case 1:
375		buf[2] |= cOscFreq_8664kHz;
376		break;
377	case 2:
378		buf[2] |= cOscFreq_12996kHz;
379		break;
380	case 3:
381		buf[2] |= cOscFreq_17328kHz;
382		break;
383	default:		/* nothing */
384		break;
385	}
386
387	dprintk(PREFIX "writing: 0w=0x%02x 1w=0x%02x 2w=0x%02x\n",
388		buf[0], buf[1], buf[2]);
389
390	rc = i2c_master_send(client, buf, 3);
391	if (rc != 3)
392		printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
393}
394
395/* ---------------------------------------------------------------------- */
396
397static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
398{
399	struct saa6588 *s = to_saa6588(sd);
400	struct saa6588_command *a = arg;
401
402	switch (cmd) {
403		/* --- close() for /dev/radio --- */
404	case SAA6588_CMD_CLOSE:
405		s->data_available_for_read = 1;
406		wake_up_interruptible(&s->read_queue);
407		s->data_available_for_read = 0;
408		a->result = 0;
409		break;
410		/* --- read() for /dev/radio --- */
411	case SAA6588_CMD_READ:
412		read_from_buf(s, a);
413		break;
414		/* --- poll() for /dev/radio --- */
415	case SAA6588_CMD_POLL:
416		a->result = 0;
417		if (s->data_available_for_read)
418			a->result |= POLLIN | POLLRDNORM;
419		poll_wait(a->instance, &s->read_queue, a->event_list);
420		break;
421
422	default:
423		/* nothing */
424		return -ENOIOCTLCMD;
425	}
426	return 0;
427}
428
429static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
430{
431	struct saa6588 *s = to_saa6588(sd);
432
433	vt->capability |= V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO;
434	if (s->sync)
435		vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
436	return 0;
437}
438
439static int saa6588_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *vt)
440{
441	struct saa6588 *s = to_saa6588(sd);
442
443	saa6588_configure(s);
444	return 0;
445}
446
447/* ----------------------------------------------------------------------- */
448
449static const struct v4l2_subdev_core_ops saa6588_core_ops = {
450	.ioctl = saa6588_ioctl,
451};
452
453static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
454	.g_tuner = saa6588_g_tuner,
455	.s_tuner = saa6588_s_tuner,
456};
457
458static const struct v4l2_subdev_ops saa6588_ops = {
459	.core = &saa6588_core_ops,
460	.tuner = &saa6588_tuner_ops,
461};
462
463/* ---------------------------------------------------------------------- */
464
465static int saa6588_probe(struct i2c_client *client,
466			 const struct i2c_device_id *id)
467{
468	struct saa6588 *s;
469	struct v4l2_subdev *sd;
470
471	v4l_info(client, "saa6588 found @ 0x%x (%s)\n",
472			client->addr << 1, client->adapter->name);
473
474	s = devm_kzalloc(&client->dev, sizeof(*s), GFP_KERNEL);
475	if (s == NULL)
476		return -ENOMEM;
477
478	s->buf_size = bufblocks * 3;
479
480	s->buffer = devm_kzalloc(&client->dev, s->buf_size, GFP_KERNEL);
481	if (s->buffer == NULL)
482		return -ENOMEM;
483	sd = &s->sd;
484	v4l2_i2c_subdev_init(sd, client, &saa6588_ops);
485	spin_lock_init(&s->lock);
486	s->block_count = 0;
487	s->wr_index = 0;
488	s->rd_index = 0;
489	s->last_blocknum = 0xff;
490	init_waitqueue_head(&s->read_queue);
491	s->data_available_for_read = 0;
492
493	saa6588_configure(s);
494
495	/* start polling via eventd */
496	INIT_DELAYED_WORK(&s->work, saa6588_work);
497	schedule_delayed_work(&s->work, 0);
498	return 0;
499}
500
501static int saa6588_remove(struct i2c_client *client)
502{
503	struct v4l2_subdev *sd = i2c_get_clientdata(client);
504	struct saa6588 *s = to_saa6588(sd);
505
506	v4l2_device_unregister_subdev(sd);
507
508	cancel_delayed_work_sync(&s->work);
509
510	return 0;
511}
512
513/* ----------------------------------------------------------------------- */
514
515static const struct i2c_device_id saa6588_id[] = {
516	{ "saa6588", 0 },
517	{ }
518};
519MODULE_DEVICE_TABLE(i2c, saa6588_id);
520
521static struct i2c_driver saa6588_driver = {
522	.driver = {
523		.owner	= THIS_MODULE,
524		.name	= "saa6588",
525	},
526	.probe		= saa6588_probe,
527	.remove		= saa6588_remove,
528	.id_table	= saa6588_id,
529};
530
531module_i2c_driver(saa6588_driver);
532