aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/radio/si470x/radio-si470x-i2c.c
blob: 5466015346a10be27b191659ff285d20b7d195bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
/*
 * drivers/media/radio/si470x/radio-si470x-i2c.c
 *
 * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
 *
 * Copyright (c) 2009 Samsung Electronics Co.Ltd
 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


/* driver definitions */
#define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 1)
#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
#define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
#define DRIVER_VERSION "1.0.1"

/* kernel includes */
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/interrupt.h>

#include "radio-si470x.h"


/* I2C Device ID List */
static const struct i2c_device_id si470x_i2c_id[] = {
	/* Generic Entry */
	{ "si470x", 0 },
	/* Terminating entry */
	{ }
};
MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);



/**************************************************************************
 * Module Parameters
 **************************************************************************/

/* Radio Nr */
static int radio_nr = -1;
module_param(radio_nr, int, 0444);
MODULE_PARM_DESC(radio_nr, "Radio Nr");

/* RDS buffer blocks */
static unsigned int rds_buf = 100;
module_param(rds_buf, uint, 0444);
MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");

/* RDS maximum block errors */
static unsigned short max_rds_errors = 1;
/* 0 means   0  errors requiring correction */
/* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
/* 2 means 3-5  errors requiring correction */
/* 3 means   6+ errors or errors in checkword, correction not possible */
module_param(max_rds_errors, ushort, 0644);
MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");



/**************************************************************************
 * I2C Definitions
 **************************************************************************/

/* Write starts with the upper byte of register 0x02 */
#define WRITE_REG_NUM		8
#define WRITE_INDEX(i)		(i + 0x02)

/* Read starts with the upper byte of register 0x0a */
#define READ_REG_NUM		RADIO_REGISTER_NUM
#define READ_INDEX(i)		((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)



/**************************************************************************
 * General Driver Functions - REGISTERs
 **************************************************************************/

/*
 * si470x_get_register - read register
 */
int si470x_get_register(struct si470x_device *radio, int regnr)
{
	u16 buf[READ_REG_NUM];
	struct i2c_msg msgs[1] = {
		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
			(void *)buf },
	};

	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
		return -EIO;

	radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);

	return 0;
}


/*
 * si470x_set_register - write register
 */
int si470x_set_register(struct si470x_device *radio, int regnr)
{
	int i;
	u16 buf[WRITE_REG_NUM];
	struct i2c_msg msgs[1] = {
		{ radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
			(void *)buf },
	};

	for (i = 0; i < WRITE_REG_NUM; i++)
		buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);

	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
		return -EIO;

	return 0;
}



/**************************************************************************
 * General Driver Functions - ENTIRE REGISTERS
 **************************************************************************/

/*
 * si470x_get_all_registers - read entire registers
 */
static int si470x_get_all_registers(struct si470x_device *radio)
{
	int i;
	u16 buf[READ_REG_NUM];
	struct i2c_msg msgs[1] = {
		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
			(void *)buf },
	};

	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
		return -EIO;

	for (i = 0; i < READ_REG_NUM; i++)
		radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);

	return 0;
}



/**************************************************************************
 * General Driver Functions - DISCONNECT_CHECK
 **************************************************************************/

/*
 * si470x_disconnect_check - check whether radio disconnects
 */
int si470x_disconnect_check(struct si470x_device *radio)
{
	return 0;
}



/**************************************************************************
 * File Operations Interface
 **************************************************************************/

/*
 * si470x_fops_open - file open
 */
int si470x_fops_open(struct file *file)
{
	struct si470x_device *radio = video_drvdata(file);
	int retval = 0;

	mutex_lock(&radio->lock);
	radio->users++;

	if (radio->users == 1) {
		/* start radio */
		retval = si470x_start(radio);
		if (retval < 0)
			goto done;

		/* enable RDS interrupt */
		radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
		radio->registers[SYSCONFIG1] |= 0x1 << 2;
		retval = si470x_set_register(radio, SYSCONFIG1);
	}

done:
	mutex_unlock(&radio->lock);
	return retval;
}


/*
 * si470x_fops_release - file release
 */
int si470x_fops_release(struct file *file)
{
	struct si470x_device *radio = video_drvdata(file);
	int retval = 0;

	/* safety check */
	if (!radio)
		return -ENODEV;

	mutex_lock(&radio->lock);
	radio->users--;
	if (radio->users == 0)
		/* stop radio */
		retval = si470x_stop(radio);

	mutex_unlock(&radio->lock);

	return retval;
}



/**************************************************************************
 * Video4Linux Interface
 **************************************************************************/

/*
 * si470x_vidioc_querycap - query device capabilities
 */
int si470x_vidioc_querycap(struct file *file, void *priv,
		struct v4l2_capability *capability)
{
	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
	capability->version = DRIVER_KERNEL_VERSION;
	capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
		V4L2_CAP_TUNER | V4L2_CAP_RADIO;

	return 0;
}



/**************************************************************************
 * I2C Interface
 **************************************************************************/

/*
 * si470x_i2c_interrupt_work - rds processing function
 */
static void si470x_i2c_interrupt_work(struct work_struct *work)
{
	struct si470x_device *radio = container_of(work,
			struct si470x_device, radio_work);
	unsigned char regnr;
	unsigned char blocknum;
	unsigned short bler; /* rds block errors */
	unsigned short rds;
	unsigned char tmpbuf[3];
	int retval = 0;

	/* safety checks */
	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
		return;

	/* Update RDS registers */
	for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++) {
		retval = si470x_get_register(radio, STATUSRSSI + regnr);
		if (retval < 0)
			return;
	}

	/* get rds blocks */
	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
		/* No RDS group ready, better luck next time */
		return;

	for (blocknum = 0; blocknum < 4; blocknum++) {
		switch (blocknum) {
		default:
			bler = (radio->registers[STATUSRSSI] &
					STATUSRSSI_BLERA) >> 9;
			rds = radio->registers[RDSA];
			break;
		case 1:
			bler = (radio->registers[READCHAN] &
					READCHAN_BLERB) >> 14;
			rds = radio->registers[RDSB];
			break;
		case 2:
			bler = (radio->registers[READCHAN] &
					READCHAN_BLERC) >> 12;
			rds = radio->registers[RDSC];
			break;
		case 3:
			bler = (radio->registers[READCHAN] &
					READCHAN_BLERD) >> 10;
			rds = radio->registers[RDSD];
			break;
		};

		/* Fill the V4L2 RDS buffer */
		put_unaligned_le16(rds, &tmpbuf);
		tmpbuf[2] = blocknum;		/* offset name */
		tmpbuf[2] |= blocknum << 3;	/* received offset */
		if (bler > max_rds_errors)
			tmpbuf[2] |= 0x80;	/* uncorrectable errors */
		else if (bler > 0)
			tmpbuf[2] |= 0x40;	/* corrected error(s) */

		/* copy RDS block to internal buffer */
		memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
		radio->wr_index += 3;

		/* wrap write pointer */
		if (radio->wr_index >= radio->buf_size)
			radio->wr_index = 0;

		/* check for overflow */
		if (radio->wr_index == radio->rd_index) {
			/* increment and wrap read pointer */
			radio->rd_index += 3;
			if (radio->rd_index >= radio->buf_size)
				radio->rd_index = 0;
		}
	}

	if (radio->wr_index != radio->rd_index)
		wake_up_interruptible(&radio->read_queue);
}


/*
 * si470x_i2c_interrupt - interrupt handler
 */
static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
{
	struct si470x_device *radio = dev_id;

	if (!work_pending(&radio->radio_work))
		schedule_work(&radio->radio_work);

	return IRQ_HANDLED;
}


/*
 * si470x_i2c_probe - probe for the device
 */
static int __devinit si470x_i2c_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
{
	struct si470x_device *radio;
	int retval = 0;
	unsigned char version_warning = 0;

	/* private data allocation and initialization */
	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
	if (!radio) {
		retval = -ENOMEM;
		goto err_initial;
	}

	INIT_WORK(&radio->radio_work, si470x_i2c_interrupt_work);
	radio->users = 0;
	radio->client = client;
	mutex_init(&radio->lock);

	/* video device allocation and initialization */
	radio->videodev = video_device_alloc();
	if (!radio->videodev) {
		retval = -ENOMEM;
		goto err_radio;
	}
	memcpy(radio->videodev, &si470x_viddev_template,
			sizeof(si470x_viddev_template));
	video_set_drvdata(radio->videodev, radio);

	/* power up : need 110ms */
	radio->registers[POWERCFG] = POWERCFG_ENABLE;
	if (si470x_set_register(radio, POWERCFG) < 0) {
		retval = -EIO;
		goto err_all;
	}
	msleep(110);

	/* get device and chip versions */
	if (si470x_get_all_registers(radio) < 0) {
		retval = -EIO;
		goto err_video;
	}
	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
			radio->registers[DEVICEID], radio->registers[CHIPID]);
	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
		dev_warn(&client->dev,
			"This driver is known to work with "
			"firmware version %hu,\n", RADIO_FW_VERSION);
		dev_warn(&client->dev,
			"but the device has firmware version %hu.\n",
			radio->registers[CHIPID] & CHIPID_FIRMWARE);
		version_warning = 1;
	}

	/* give out version warning */
	if (version_warning == 1) {
		dev_warn(&client->dev,
			"If you have some trouble using this driver,\n");
		dev_warn(&client->dev,
			"please report to V4L ML at "
			"linux-media@vger.kernel.org\n");
	}

	/* set initial frequency */
	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */

	/* rds buffer allocation */
	radio->buf_size = rds_buf * 3;
	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
	if (!radio->buffer) {
		retval = -EIO;
		goto err_video;
	}

	/* rds buffer configuration */
	radio->wr_index = 0;
	radio->rd_index = 0;
	init_waitqueue_head(&radio->read_queue);

	retval = request_irq(client->irq, si470x_i2c_interrupt,
			IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
	if (retval) {
		dev_err(&client->dev, "Failed to register interrupt\n");
		goto err_rds;
	}

	/* register video device */
	retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
			radio_nr);
	if (retval) {
		dev_warn(&client->dev, "Could not register video device\n");
		goto err_all;
	}
	i2c_set_clientdata(client, radio);

	return 0;
err_all:
	free_irq(client->irq, radio);
err_rds:
	kfree(radio->buffer);
err_video:
	video_device_release(radio->videodev);
err_radio:
	kfree(radio);
err_initial:
	return retval;
}


/*
 * si470x_i2c_remove - remove the device
 */
static __devexit int si470x_i2c_remove(struct i2c_client *client)
{
	struct si470x_device *radio = i2c_get_clientdata(client);

	free_irq(client->irq, radio);
	cancel_work_sync(&radio->radio_work);
	video_unregister_device(radio->videodev);
	kfree(radio);
	i2c_set_clientdata(client, NULL);

	return 0;
}


#ifdef CONFIG_PM
/*
 * si470x_i2c_suspend - suspend the device
 */
static int si470x_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
{
	struct si470x_device *radio = i2c_get_clientdata(client);

	/* power down */
	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
	if (si470x_set_register(radio, POWERCFG) < 0)
		return -EIO;

	return 0;
}


/*
 * si470x_i2c_resume - resume the device
 */
static int si470x_i2c_resume(struct i2c_client *client)
{
	struct si470x_device *radio = i2c_get_clientdata(client);

	/* power up : need 110ms */
	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
	if (si470x_set_register(radio, POWERCFG) < 0)
		return -EIO;
	msleep(110);

	return 0;
}
#else
#define si470x_i2c_suspend	NULL
#define si470x_i2c_resume	NULL
#endif


/*
 * si470x_i2c_driver - i2c driver interface
 */
static struct i2c_driver si470x_i2c_driver = {
	.driver = {
		.name		= "si470x",
		.owner		= THIS_MODULE,
	},
	.probe			= si470x_i2c_probe,
	.remove			= __devexit_p(si470x_i2c_remove),
	.suspend		= si470x_i2c_suspend,
	.resume			= si470x_i2c_resume,
	.id_table		= si470x_i2c_id,
};



/**************************************************************************
 * Module Interface
 **************************************************************************/

/*
 * si470x_i2c_init - module init
 */
static int __init si470x_i2c_init(void)
{
	printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
	return i2c_add_driver(&si470x_i2c_driver);
}


/*
 * si470x_i2c_exit - module exit
 */
static void __exit si470x_i2c_exit(void)
{
	i2c_del_driver(&si470x_i2c_driver);
}


module_init(si470x_i2c_init);
module_exit(si470x_i2c_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);