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_CARD "Silicon Labs Si470x FM Radio Receiver"
28 #define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
29 #define DRIVER_VERSION "1.0.2"
30 
31 /* kernel includes */
32 #include <linux/i2c.h>
33 #include <linux/slab.h>
34 #include <linux/delay.h>
35 #include <linux/interrupt.h>
36 
37 #include "radio-si470x.h"
38 
39 
40 /* I2C Device ID List */
41 static const struct i2c_device_id si470x_i2c_id[] = {
42 	/* Generic Entry */
43 	{ "si470x", 0 },
44 	/* Terminating entry */
45 	{ }
46 };
47 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
48 
49 
50 
51 /**************************************************************************
52  * Module Parameters
53  **************************************************************************/
54 
55 /* Radio Nr */
56 static int radio_nr = -1;
57 module_param(radio_nr, int, 0444);
58 MODULE_PARM_DESC(radio_nr, "Radio Nr");
59 
60 /* RDS buffer blocks */
61 static unsigned int rds_buf = 100;
62 module_param(rds_buf, uint, 0444);
63 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
64 
65 /* RDS maximum block errors */
66 static unsigned short max_rds_errors = 1;
67 /* 0 means   0  errors requiring correction */
68 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
69 /* 2 means 3-5  errors requiring correction */
70 /* 3 means   6+ errors or errors in checkword, correction not possible */
71 module_param(max_rds_errors, ushort, 0644);
72 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
73 
74 
75 
76 /**************************************************************************
77  * I2C Definitions
78  **************************************************************************/
79 
80 /* Write starts with the upper byte of register 0x02 */
81 #define WRITE_REG_NUM		8
82 #define WRITE_INDEX(i)		(i + 0x02)
83 
84 /* Read starts with the upper byte of register 0x0a */
85 #define READ_REG_NUM		RADIO_REGISTER_NUM
86 #define READ_INDEX(i)		((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
87 
88 
89 
90 /**************************************************************************
91  * General Driver Functions - REGISTERs
92  **************************************************************************/
93 
94 /*
95  * si470x_get_register - read register
96  */
97 int si470x_get_register(struct si470x_device *radio, int regnr)
98 {
99 	u16 buf[READ_REG_NUM];
100 	struct i2c_msg msgs[1] = {
101 		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
102 			(void *)buf },
103 	};
104 
105 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
106 		return -EIO;
107 
108 	radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
109 
110 	return 0;
111 }
112 
113 
114 /*
115  * si470x_set_register - write register
116  */
117 int si470x_set_register(struct si470x_device *radio, int regnr)
118 {
119 	int i;
120 	u16 buf[WRITE_REG_NUM];
121 	struct i2c_msg msgs[1] = {
122 		{ radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
123 			(void *)buf },
124 	};
125 
126 	for (i = 0; i < WRITE_REG_NUM; i++)
127 		buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
128 
129 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
130 		return -EIO;
131 
132 	return 0;
133 }
134 
135 
136 
137 /**************************************************************************
138  * General Driver Functions - ENTIRE REGISTERS
139  **************************************************************************/
140 
141 /*
142  * si470x_get_all_registers - read entire registers
143  */
144 static int si470x_get_all_registers(struct si470x_device *radio)
145 {
146 	int i;
147 	u16 buf[READ_REG_NUM];
148 	struct i2c_msg msgs[1] = {
149 		{ radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
150 			(void *)buf },
151 	};
152 
153 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
154 		return -EIO;
155 
156 	for (i = 0; i < READ_REG_NUM; i++)
157 		radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
158 
159 	return 0;
160 }
161 
162 
163 
164 /**************************************************************************
165  * General Driver Functions - DISCONNECT_CHECK
166  **************************************************************************/
167 
168 /*
169  * si470x_disconnect_check - check whether radio disconnects
170  */
171 int si470x_disconnect_check(struct si470x_device *radio)
172 {
173 	return 0;
174 }
175 
176 
177 
178 /**************************************************************************
179  * File Operations Interface
180  **************************************************************************/
181 
182 /*
183  * si470x_fops_open - file open
184  */
185 int si470x_fops_open(struct file *file)
186 {
187 	struct si470x_device *radio = video_drvdata(file);
188 	int retval = 0;
189 
190 	mutex_lock(&radio->lock);
191 	radio->users++;
192 
193 	if (radio->users == 1) {
194 		/* start radio */
195 		retval = si470x_start(radio);
196 		if (retval < 0)
197 			goto done;
198 
199 		/* enable RDS / STC interrupt */
200 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
201 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
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->capabilities = V4L2_CAP_HW_FREQ_SEEK |
251 		V4L2_CAP_TUNER | V4L2_CAP_RADIO;
252 
253 	return 0;
254 }
255 
256 
257 
258 /**************************************************************************
259  * I2C Interface
260  **************************************************************************/
261 
262 /*
263  * si470x_i2c_interrupt - interrupt handler
264  */
265 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
266 {
267 	struct si470x_device *radio = dev_id;
268 	unsigned char regnr;
269 	unsigned char blocknum;
270 	unsigned short bler; /* rds block errors */
271 	unsigned short rds;
272 	unsigned char tmpbuf[3];
273 	int retval = 0;
274 
275 	/* check Seek/Tune Complete */
276 	retval = si470x_get_register(radio, STATUSRSSI);
277 	if (retval < 0)
278 		goto end;
279 
280 	if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
281 		complete(&radio->completion);
282 
283 	/* safety checks */
284 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
285 		goto end;
286 
287 	/* Update RDS registers */
288 	for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
289 		retval = si470x_get_register(radio, STATUSRSSI + regnr);
290 		if (retval < 0)
291 			goto end;
292 	}
293 
294 	/* get rds blocks */
295 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
296 		/* No RDS group ready, better luck next time */
297 		goto end;
298 
299 	for (blocknum = 0; blocknum < 4; blocknum++) {
300 		switch (blocknum) {
301 		default:
302 			bler = (radio->registers[STATUSRSSI] &
303 					STATUSRSSI_BLERA) >> 9;
304 			rds = radio->registers[RDSA];
305 			break;
306 		case 1:
307 			bler = (radio->registers[READCHAN] &
308 					READCHAN_BLERB) >> 14;
309 			rds = radio->registers[RDSB];
310 			break;
311 		case 2:
312 			bler = (radio->registers[READCHAN] &
313 					READCHAN_BLERC) >> 12;
314 			rds = radio->registers[RDSC];
315 			break;
316 		case 3:
317 			bler = (radio->registers[READCHAN] &
318 					READCHAN_BLERD) >> 10;
319 			rds = radio->registers[RDSD];
320 			break;
321 		};
322 
323 		/* Fill the V4L2 RDS buffer */
324 		put_unaligned_le16(rds, &tmpbuf);
325 		tmpbuf[2] = blocknum;		/* offset name */
326 		tmpbuf[2] |= blocknum << 3;	/* received offset */
327 		if (bler > max_rds_errors)
328 			tmpbuf[2] |= 0x80;	/* uncorrectable errors */
329 		else if (bler > 0)
330 			tmpbuf[2] |= 0x40;	/* corrected error(s) */
331 
332 		/* copy RDS block to internal buffer */
333 		memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
334 		radio->wr_index += 3;
335 
336 		/* wrap write pointer */
337 		if (radio->wr_index >= radio->buf_size)
338 			radio->wr_index = 0;
339 
340 		/* check for overflow */
341 		if (radio->wr_index == radio->rd_index) {
342 			/* increment and wrap read pointer */
343 			radio->rd_index += 3;
344 			if (radio->rd_index >= radio->buf_size)
345 				radio->rd_index = 0;
346 		}
347 	}
348 
349 	if (radio->wr_index != radio->rd_index)
350 		wake_up_interruptible(&radio->read_queue);
351 
352 end:
353 	return IRQ_HANDLED;
354 }
355 
356 
357 /*
358  * si470x_i2c_probe - probe for the device
359  */
360 static int __devinit si470x_i2c_probe(struct i2c_client *client,
361 		const struct i2c_device_id *id)
362 {
363 	struct si470x_device *radio;
364 	int retval = 0;
365 	unsigned char version_warning = 0;
366 
367 	/* private data allocation and initialization */
368 	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
369 	if (!radio) {
370 		retval = -ENOMEM;
371 		goto err_initial;
372 	}
373 
374 	radio->users = 0;
375 	radio->client = client;
376 	mutex_init(&radio->lock);
377 
378 	/* video device allocation and initialization */
379 	radio->videodev = video_device_alloc();
380 	if (!radio->videodev) {
381 		retval = -ENOMEM;
382 		goto err_radio;
383 	}
384 	memcpy(radio->videodev, &si470x_viddev_template,
385 			sizeof(si470x_viddev_template));
386 	video_set_drvdata(radio->videodev, radio);
387 
388 	/* power up : need 110ms */
389 	radio->registers[POWERCFG] = POWERCFG_ENABLE;
390 	if (si470x_set_register(radio, POWERCFG) < 0) {
391 		retval = -EIO;
392 		goto err_video;
393 	}
394 	msleep(110);
395 
396 	/* get device and chip versions */
397 	if (si470x_get_all_registers(radio) < 0) {
398 		retval = -EIO;
399 		goto err_video;
400 	}
401 	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
402 			radio->registers[DEVICEID], radio->registers[CHIPID]);
403 	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
404 		dev_warn(&client->dev,
405 			"This driver is known to work with "
406 			"firmware version %hu,\n", RADIO_FW_VERSION);
407 		dev_warn(&client->dev,
408 			"but the device has firmware version %hu.\n",
409 			radio->registers[CHIPID] & CHIPID_FIRMWARE);
410 		version_warning = 1;
411 	}
412 
413 	/* give out version warning */
414 	if (version_warning == 1) {
415 		dev_warn(&client->dev,
416 			"If you have some trouble using this driver,\n");
417 		dev_warn(&client->dev,
418 			"please report to V4L ML at "
419 			"linux-media@vger.kernel.org\n");
420 	}
421 
422 	/* set initial frequency */
423 	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
424 
425 	/* rds buffer allocation */
426 	radio->buf_size = rds_buf * 3;
427 	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
428 	if (!radio->buffer) {
429 		retval = -EIO;
430 		goto err_video;
431 	}
432 
433 	/* rds buffer configuration */
434 	radio->wr_index = 0;
435 	radio->rd_index = 0;
436 	init_waitqueue_head(&radio->read_queue);
437 
438 	/* mark Seek/Tune Complete Interrupt enabled */
439 	radio->stci_enabled = true;
440 	init_completion(&radio->completion);
441 
442 	retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
443 			IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
444 	if (retval) {
445 		dev_err(&client->dev, "Failed to register interrupt\n");
446 		goto err_rds;
447 	}
448 
449 	/* register video device */
450 	retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
451 			radio_nr);
452 	if (retval) {
453 		dev_warn(&client->dev, "Could not register video device\n");
454 		goto err_all;
455 	}
456 	i2c_set_clientdata(client, radio);
457 
458 	return 0;
459 err_all:
460 	free_irq(client->irq, radio);
461 err_rds:
462 	kfree(radio->buffer);
463 err_video:
464 	video_device_release(radio->videodev);
465 err_radio:
466 	kfree(radio);
467 err_initial:
468 	return retval;
469 }
470 
471 
472 /*
473  * si470x_i2c_remove - remove the device
474  */
475 static __devexit int si470x_i2c_remove(struct i2c_client *client)
476 {
477 	struct si470x_device *radio = i2c_get_clientdata(client);
478 
479 	free_irq(client->irq, radio);
480 	video_unregister_device(radio->videodev);
481 	kfree(radio);
482 
483 	return 0;
484 }
485 
486 
487 #ifdef CONFIG_PM
488 /*
489  * si470x_i2c_suspend - suspend the device
490  */
491 static int si470x_i2c_suspend(struct device *dev)
492 {
493 	struct i2c_client *client = to_i2c_client(dev);
494 	struct si470x_device *radio = i2c_get_clientdata(client);
495 
496 	/* power down */
497 	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
498 	if (si470x_set_register(radio, POWERCFG) < 0)
499 		return -EIO;
500 
501 	return 0;
502 }
503 
504 
505 /*
506  * si470x_i2c_resume - resume the device
507  */
508 static int si470x_i2c_resume(struct device *dev)
509 {
510 	struct i2c_client *client = to_i2c_client(dev);
511 	struct si470x_device *radio = i2c_get_clientdata(client);
512 
513 	/* power up : need 110ms */
514 	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
515 	if (si470x_set_register(radio, POWERCFG) < 0)
516 		return -EIO;
517 	msleep(110);
518 
519 	return 0;
520 }
521 
522 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
523 #endif
524 
525 
526 /*
527  * si470x_i2c_driver - i2c driver interface
528  */
529 static struct i2c_driver si470x_i2c_driver = {
530 	.driver = {
531 		.name		= "si470x",
532 		.owner		= THIS_MODULE,
533 #ifdef CONFIG_PM
534 		.pm		= &si470x_i2c_pm,
535 #endif
536 	},
537 	.probe			= si470x_i2c_probe,
538 	.remove			= __devexit_p(si470x_i2c_remove),
539 	.id_table		= si470x_i2c_id,
540 };
541 
542 module_i2c_driver(si470x_i2c_driver);
543 
544 MODULE_LICENSE("GPL");
545 MODULE_AUTHOR(DRIVER_AUTHOR);
546 MODULE_DESCRIPTION(DRIVER_DESC);
547 MODULE_VERSION(DRIVER_VERSION);
548