xref: /linux/drivers/media/radio/si470x/radio-si470x-i2c.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  * drivers/media/radio/si470x/radio-si470x-i2c.c
3  *
4  * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
5  *
6  * Copyright (c) 2009 Samsung Electronics Co.Ltd
7  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 
24 
25 /* driver definitions */
26 #define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
27 #define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 1)
28 #define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
29 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
30 #define DRIVER_VERSION "1.0.1"
31 
32 /* kernel includes */
33 #include <linux/i2c.h>
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/interrupt.h>
37 
38 #include "radio-si470x.h"
39 
40 
41 /* I2C Device ID List */
42 static const struct i2c_device_id si470x_i2c_id[] = {
43 	/* Generic Entry */
44 	{ "si470x", 0 },
45 	/* Terminating entry */
46 	{ }
47 };
48 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
49 
50 
51 
52 /**************************************************************************
53  * Module Parameters
54  **************************************************************************/
55 
56 /* Radio Nr */
57 static int radio_nr = -1;
58 module_param(radio_nr, int, 0444);
59 MODULE_PARM_DESC(radio_nr, "Radio Nr");
60 
61 /* RDS buffer blocks */
62 static unsigned int rds_buf = 100;
63 module_param(rds_buf, uint, 0444);
64 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
65 
66 /* RDS maximum block errors */
67 static unsigned short max_rds_errors = 1;
68 /* 0 means   0  errors requiring correction */
69 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
70 /* 2 means 3-5  errors requiring correction */
71 /* 3 means   6+ errors or errors in checkword, correction not possible */
72 module_param(max_rds_errors, ushort, 0644);
73 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
74 
75 
76 
77 /**************************************************************************
78  * I2C Definitions
79  **************************************************************************/
80 
81 /* Write starts with the upper byte of register 0x02 */
82 #define WRITE_REG_NUM		8
83 #define WRITE_INDEX(i)		(i + 0x02)
84 
85 /* Read starts with the upper byte of register 0x0a */
86 #define READ_REG_NUM		RADIO_REGISTER_NUM
87 #define READ_INDEX(i)		((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
88 
89 
90 
91 /**************************************************************************
92  * General Driver Functions - REGISTERs
93  **************************************************************************/
94 
95 /*
96  * si470x_get_register - read register
97  */
98 int si470x_get_register(struct si470x_device *radio, int regnr)
99 {
100 	u16 buf[READ_REG_NUM];
101 	struct i2c_msg msgs[1] = {
102 		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
103 			(void *)buf },
104 	};
105 
106 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
107 		return -EIO;
108 
109 	radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
110 
111 	return 0;
112 }
113 
114 
115 /*
116  * si470x_set_register - write register
117  */
118 int si470x_set_register(struct si470x_device *radio, int regnr)
119 {
120 	int i;
121 	u16 buf[WRITE_REG_NUM];
122 	struct i2c_msg msgs[1] = {
123 		{ radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
124 			(void *)buf },
125 	};
126 
127 	for (i = 0; i < WRITE_REG_NUM; i++)
128 		buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
129 
130 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
131 		return -EIO;
132 
133 	return 0;
134 }
135 
136 
137 
138 /**************************************************************************
139  * General Driver Functions - ENTIRE REGISTERS
140  **************************************************************************/
141 
142 /*
143  * si470x_get_all_registers - read entire registers
144  */
145 static int si470x_get_all_registers(struct si470x_device *radio)
146 {
147 	int i;
148 	u16 buf[READ_REG_NUM];
149 	struct i2c_msg msgs[1] = {
150 		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
151 			(void *)buf },
152 	};
153 
154 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
155 		return -EIO;
156 
157 	for (i = 0; i < READ_REG_NUM; i++)
158 		radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
159 
160 	return 0;
161 }
162 
163 
164 
165 /**************************************************************************
166  * General Driver Functions - DISCONNECT_CHECK
167  **************************************************************************/
168 
169 /*
170  * si470x_disconnect_check - check whether radio disconnects
171  */
172 int si470x_disconnect_check(struct si470x_device *radio)
173 {
174 	return 0;
175 }
176 
177 
178 
179 /**************************************************************************
180  * File Operations Interface
181  **************************************************************************/
182 
183 /*
184  * si470x_fops_open - file open
185  */
186 int si470x_fops_open(struct file *file)
187 {
188 	struct si470x_device *radio = video_drvdata(file);
189 	int retval = 0;
190 
191 	mutex_lock(&radio->lock);
192 	radio->users++;
193 
194 	if (radio->users == 1) {
195 		/* start radio */
196 		retval = si470x_start(radio);
197 		if (retval < 0)
198 			goto done;
199 
200 		/* enable RDS interrupt */
201 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
202 		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
203 		radio->registers[SYSCONFIG1] |= 0x1 << 2;
204 		retval = si470x_set_register(radio, SYSCONFIG1);
205 	}
206 
207 done:
208 	mutex_unlock(&radio->lock);
209 	return retval;
210 }
211 
212 
213 /*
214  * si470x_fops_release - file release
215  */
216 int si470x_fops_release(struct file *file)
217 {
218 	struct si470x_device *radio = video_drvdata(file);
219 	int retval = 0;
220 
221 	/* safety check */
222 	if (!radio)
223 		return -ENODEV;
224 
225 	mutex_lock(&radio->lock);
226 	radio->users--;
227 	if (radio->users == 0)
228 		/* stop radio */
229 		retval = si470x_stop(radio);
230 
231 	mutex_unlock(&radio->lock);
232 
233 	return retval;
234 }
235 
236 
237 
238 /**************************************************************************
239  * Video4Linux Interface
240  **************************************************************************/
241 
242 /*
243  * si470x_vidioc_querycap - query device capabilities
244  */
245 int si470x_vidioc_querycap(struct file *file, void *priv,
246 		struct v4l2_capability *capability)
247 {
248 	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
249 	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
250 	capability->version = DRIVER_KERNEL_VERSION;
251 	capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
252 		V4L2_CAP_TUNER | V4L2_CAP_RADIO;
253 
254 	return 0;
255 }
256 
257 
258 
259 /**************************************************************************
260  * I2C Interface
261  **************************************************************************/
262 
263 /*
264  * si470x_i2c_interrupt_work - rds processing function
265  */
266 static void si470x_i2c_interrupt_work(struct work_struct *work)
267 {
268 	struct si470x_device *radio = container_of(work,
269 			struct si470x_device, radio_work);
270 	unsigned char regnr;
271 	unsigned char blocknum;
272 	unsigned short bler; /* rds block errors */
273 	unsigned short rds;
274 	unsigned char tmpbuf[3];
275 	int retval = 0;
276 
277 	/* safety checks */
278 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
279 		return;
280 
281 	/* Update RDS registers */
282 	for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++) {
283 		retval = si470x_get_register(radio, STATUSRSSI + regnr);
284 		if (retval < 0)
285 			return;
286 	}
287 
288 	/* get rds blocks */
289 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
290 		/* No RDS group ready, better luck next time */
291 		return;
292 
293 	for (blocknum = 0; blocknum < 4; blocknum++) {
294 		switch (blocknum) {
295 		default:
296 			bler = (radio->registers[STATUSRSSI] &
297 					STATUSRSSI_BLERA) >> 9;
298 			rds = radio->registers[RDSA];
299 			break;
300 		case 1:
301 			bler = (radio->registers[READCHAN] &
302 					READCHAN_BLERB) >> 14;
303 			rds = radio->registers[RDSB];
304 			break;
305 		case 2:
306 			bler = (radio->registers[READCHAN] &
307 					READCHAN_BLERC) >> 12;
308 			rds = radio->registers[RDSC];
309 			break;
310 		case 3:
311 			bler = (radio->registers[READCHAN] &
312 					READCHAN_BLERD) >> 10;
313 			rds = radio->registers[RDSD];
314 			break;
315 		};
316 
317 		/* Fill the V4L2 RDS buffer */
318 		put_unaligned_le16(rds, &tmpbuf);
319 		tmpbuf[2] = blocknum;		/* offset name */
320 		tmpbuf[2] |= blocknum << 3;	/* received offset */
321 		if (bler > max_rds_errors)
322 			tmpbuf[2] |= 0x80;	/* uncorrectable errors */
323 		else if (bler > 0)
324 			tmpbuf[2] |= 0x40;	/* corrected error(s) */
325 
326 		/* copy RDS block to internal buffer */
327 		memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
328 		radio->wr_index += 3;
329 
330 		/* wrap write pointer */
331 		if (radio->wr_index >= radio->buf_size)
332 			radio->wr_index = 0;
333 
334 		/* check for overflow */
335 		if (radio->wr_index == radio->rd_index) {
336 			/* increment and wrap read pointer */
337 			radio->rd_index += 3;
338 			if (radio->rd_index >= radio->buf_size)
339 				radio->rd_index = 0;
340 		}
341 	}
342 
343 	if (radio->wr_index != radio->rd_index)
344 		wake_up_interruptible(&radio->read_queue);
345 }
346 
347 
348 /*
349  * si470x_i2c_interrupt - interrupt handler
350  */
351 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
352 {
353 	struct si470x_device *radio = dev_id;
354 
355 	if (!work_pending(&radio->radio_work))
356 		schedule_work(&radio->radio_work);
357 
358 	return IRQ_HANDLED;
359 }
360 
361 
362 /*
363  * si470x_i2c_probe - probe for the device
364  */
365 static int __devinit si470x_i2c_probe(struct i2c_client *client,
366 		const struct i2c_device_id *id)
367 {
368 	struct si470x_device *radio;
369 	int retval = 0;
370 	unsigned char version_warning = 0;
371 
372 	/* private data allocation and initialization */
373 	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
374 	if (!radio) {
375 		retval = -ENOMEM;
376 		goto err_initial;
377 	}
378 
379 	INIT_WORK(&radio->radio_work, si470x_i2c_interrupt_work);
380 	radio->users = 0;
381 	radio->client = client;
382 	mutex_init(&radio->lock);
383 
384 	/* video device allocation and initialization */
385 	radio->videodev = video_device_alloc();
386 	if (!radio->videodev) {
387 		retval = -ENOMEM;
388 		goto err_radio;
389 	}
390 	memcpy(radio->videodev, &si470x_viddev_template,
391 			sizeof(si470x_viddev_template));
392 	video_set_drvdata(radio->videodev, radio);
393 
394 	/* power up : need 110ms */
395 	radio->registers[POWERCFG] = POWERCFG_ENABLE;
396 	if (si470x_set_register(radio, POWERCFG) < 0) {
397 		retval = -EIO;
398 		goto err_all;
399 	}
400 	msleep(110);
401 
402 	/* get device and chip versions */
403 	if (si470x_get_all_registers(radio) < 0) {
404 		retval = -EIO;
405 		goto err_video;
406 	}
407 	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
408 			radio->registers[DEVICEID], radio->registers[CHIPID]);
409 	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
410 		dev_warn(&client->dev,
411 			"This driver is known to work with "
412 			"firmware version %hu,\n", RADIO_FW_VERSION);
413 		dev_warn(&client->dev,
414 			"but the device has firmware version %hu.\n",
415 			radio->registers[CHIPID] & CHIPID_FIRMWARE);
416 		version_warning = 1;
417 	}
418 
419 	/* give out version warning */
420 	if (version_warning == 1) {
421 		dev_warn(&client->dev,
422 			"If you have some trouble using this driver,\n");
423 		dev_warn(&client->dev,
424 			"please report to V4L ML at "
425 			"linux-media@vger.kernel.org\n");
426 	}
427 
428 	/* set initial frequency */
429 	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
430 
431 	/* rds buffer allocation */
432 	radio->buf_size = rds_buf * 3;
433 	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
434 	if (!radio->buffer) {
435 		retval = -EIO;
436 		goto err_video;
437 	}
438 
439 	/* rds buffer configuration */
440 	radio->wr_index = 0;
441 	radio->rd_index = 0;
442 	init_waitqueue_head(&radio->read_queue);
443 
444 	retval = request_irq(client->irq, si470x_i2c_interrupt,
445 			IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
446 	if (retval) {
447 		dev_err(&client->dev, "Failed to register interrupt\n");
448 		goto err_rds;
449 	}
450 
451 	/* register video device */
452 	retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
453 			radio_nr);
454 	if (retval) {
455 		dev_warn(&client->dev, "Could not register video device\n");
456 		goto err_all;
457 	}
458 	i2c_set_clientdata(client, radio);
459 
460 	return 0;
461 err_all:
462 	free_irq(client->irq, radio);
463 err_rds:
464 	kfree(radio->buffer);
465 err_video:
466 	video_device_release(radio->videodev);
467 err_radio:
468 	kfree(radio);
469 err_initial:
470 	return retval;
471 }
472 
473 
474 /*
475  * si470x_i2c_remove - remove the device
476  */
477 static __devexit int si470x_i2c_remove(struct i2c_client *client)
478 {
479 	struct si470x_device *radio = i2c_get_clientdata(client);
480 
481 	free_irq(client->irq, radio);
482 	cancel_work_sync(&radio->radio_work);
483 	video_unregister_device(radio->videodev);
484 	kfree(radio);
485 
486 	return 0;
487 }
488 
489 
490 #ifdef CONFIG_PM
491 /*
492  * si470x_i2c_suspend - suspend the device
493  */
494 static int si470x_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
495 {
496 	struct si470x_device *radio = i2c_get_clientdata(client);
497 
498 	/* power down */
499 	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
500 	if (si470x_set_register(radio, POWERCFG) < 0)
501 		return -EIO;
502 
503 	return 0;
504 }
505 
506 
507 /*
508  * si470x_i2c_resume - resume the device
509  */
510 static int si470x_i2c_resume(struct i2c_client *client)
511 {
512 	struct si470x_device *radio = i2c_get_clientdata(client);
513 
514 	/* power up : need 110ms */
515 	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
516 	if (si470x_set_register(radio, POWERCFG) < 0)
517 		return -EIO;
518 	msleep(110);
519 
520 	return 0;
521 }
522 #else
523 #define si470x_i2c_suspend	NULL
524 #define si470x_i2c_resume	NULL
525 #endif
526 
527 
528 /*
529  * si470x_i2c_driver - i2c driver interface
530  */
531 static struct i2c_driver si470x_i2c_driver = {
532 	.driver = {
533 		.name		= "si470x",
534 		.owner		= THIS_MODULE,
535 	},
536 	.probe			= si470x_i2c_probe,
537 	.remove			= __devexit_p(si470x_i2c_remove),
538 	.suspend		= si470x_i2c_suspend,
539 	.resume			= si470x_i2c_resume,
540 	.id_table		= si470x_i2c_id,
541 };
542 
543 
544 
545 /**************************************************************************
546  * Module Interface
547  **************************************************************************/
548 
549 /*
550  * si470x_i2c_init - module init
551  */
552 static int __init si470x_i2c_init(void)
553 {
554 	printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
555 	return i2c_add_driver(&si470x_i2c_driver);
556 }
557 
558 
559 /*
560  * si470x_i2c_exit - module exit
561  */
562 static void __exit si470x_i2c_exit(void)
563 {
564 	i2c_del_driver(&si470x_i2c_driver);
565 }
566 
567 
568 module_init(si470x_i2c_init);
569 module_exit(si470x_i2c_exit);
570 
571 MODULE_LICENSE("GPL");
572 MODULE_AUTHOR(DRIVER_AUTHOR);
573 MODULE_DESCRIPTION(DRIVER_DESC);
574 MODULE_VERSION(DRIVER_VERSION);
575