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  * File Operations Interface
166  **************************************************************************/
167 
168 /*
169  * si470x_fops_open - file open
170  */
171 int si470x_fops_open(struct file *file)
172 {
173 	struct si470x_device *radio = video_drvdata(file);
174 	int retval = v4l2_fh_open(file);
175 
176 	if (retval)
177 		return retval;
178 
179 	if (v4l2_fh_is_singular_file(file)) {
180 		/* start radio */
181 		retval = si470x_start(radio);
182 		if (retval < 0)
183 			goto done;
184 
185 		/* enable RDS / STC interrupt */
186 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
187 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
188 		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
189 		radio->registers[SYSCONFIG1] |= 0x1 << 2;
190 		retval = si470x_set_register(radio, SYSCONFIG1);
191 	}
192 
193 done:
194 	if (retval)
195 		v4l2_fh_release(file);
196 	return retval;
197 }
198 
199 
200 /*
201  * si470x_fops_release - file release
202  */
203 int si470x_fops_release(struct file *file)
204 {
205 	struct si470x_device *radio = video_drvdata(file);
206 
207 	if (v4l2_fh_is_singular_file(file))
208 		/* stop radio */
209 		si470x_stop(radio);
210 
211 	return v4l2_fh_release(file);
212 }
213 
214 
215 
216 /**************************************************************************
217  * Video4Linux Interface
218  **************************************************************************/
219 
220 /*
221  * si470x_vidioc_querycap - query device capabilities
222  */
223 int si470x_vidioc_querycap(struct file *file, void *priv,
224 		struct v4l2_capability *capability)
225 {
226 	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
227 	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
228 	capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
229 		V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
230 	capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
231 
232 	return 0;
233 }
234 
235 
236 
237 /**************************************************************************
238  * I2C Interface
239  **************************************************************************/
240 
241 /*
242  * si470x_i2c_interrupt - interrupt handler
243  */
244 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
245 {
246 	struct si470x_device *radio = dev_id;
247 	unsigned char regnr;
248 	unsigned char blocknum;
249 	unsigned short bler; /* rds block errors */
250 	unsigned short rds;
251 	unsigned char tmpbuf[3];
252 	int retval = 0;
253 
254 	/* check Seek/Tune Complete */
255 	retval = si470x_get_register(radio, STATUSRSSI);
256 	if (retval < 0)
257 		goto end;
258 
259 	if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
260 		complete(&radio->completion);
261 
262 	/* safety checks */
263 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
264 		goto end;
265 
266 	/* Update RDS registers */
267 	for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
268 		retval = si470x_get_register(radio, STATUSRSSI + regnr);
269 		if (retval < 0)
270 			goto end;
271 	}
272 
273 	/* get rds blocks */
274 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
275 		/* No RDS group ready, better luck next time */
276 		goto end;
277 
278 	for (blocknum = 0; blocknum < 4; blocknum++) {
279 		switch (blocknum) {
280 		default:
281 			bler = (radio->registers[STATUSRSSI] &
282 					STATUSRSSI_BLERA) >> 9;
283 			rds = radio->registers[RDSA];
284 			break;
285 		case 1:
286 			bler = (radio->registers[READCHAN] &
287 					READCHAN_BLERB) >> 14;
288 			rds = radio->registers[RDSB];
289 			break;
290 		case 2:
291 			bler = (radio->registers[READCHAN] &
292 					READCHAN_BLERC) >> 12;
293 			rds = radio->registers[RDSC];
294 			break;
295 		case 3:
296 			bler = (radio->registers[READCHAN] &
297 					READCHAN_BLERD) >> 10;
298 			rds = radio->registers[RDSD];
299 			break;
300 		};
301 
302 		/* Fill the V4L2 RDS buffer */
303 		put_unaligned_le16(rds, &tmpbuf);
304 		tmpbuf[2] = blocknum;		/* offset name */
305 		tmpbuf[2] |= blocknum << 3;	/* received offset */
306 		if (bler > max_rds_errors)
307 			tmpbuf[2] |= 0x80;	/* uncorrectable errors */
308 		else if (bler > 0)
309 			tmpbuf[2] |= 0x40;	/* corrected error(s) */
310 
311 		/* copy RDS block to internal buffer */
312 		memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
313 		radio->wr_index += 3;
314 
315 		/* wrap write pointer */
316 		if (radio->wr_index >= radio->buf_size)
317 			radio->wr_index = 0;
318 
319 		/* check for overflow */
320 		if (radio->wr_index == radio->rd_index) {
321 			/* increment and wrap read pointer */
322 			radio->rd_index += 3;
323 			if (radio->rd_index >= radio->buf_size)
324 				radio->rd_index = 0;
325 		}
326 	}
327 
328 	if (radio->wr_index != radio->rd_index)
329 		wake_up_interruptible(&radio->read_queue);
330 
331 end:
332 	return IRQ_HANDLED;
333 }
334 
335 
336 /*
337  * si470x_i2c_probe - probe for the device
338  */
339 static int __devinit si470x_i2c_probe(struct i2c_client *client,
340 		const struct i2c_device_id *id)
341 {
342 	struct si470x_device *radio;
343 	int retval = 0;
344 	unsigned char version_warning = 0;
345 
346 	/* private data allocation and initialization */
347 	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
348 	if (!radio) {
349 		retval = -ENOMEM;
350 		goto err_initial;
351 	}
352 
353 	radio->client = client;
354 	radio->band = 1; /* Default to 76 - 108 MHz */
355 	mutex_init(&radio->lock);
356 	init_completion(&radio->completion);
357 
358 	/* video device initialization */
359 	radio->videodev = si470x_viddev_template;
360 	video_set_drvdata(&radio->videodev, radio);
361 
362 	/* power up : need 110ms */
363 	radio->registers[POWERCFG] = POWERCFG_ENABLE;
364 	if (si470x_set_register(radio, POWERCFG) < 0) {
365 		retval = -EIO;
366 		goto err_radio;
367 	}
368 	msleep(110);
369 
370 	/* get device and chip versions */
371 	if (si470x_get_all_registers(radio) < 0) {
372 		retval = -EIO;
373 		goto err_radio;
374 	}
375 	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
376 			radio->registers[DEVICEID], radio->registers[CHIPID]);
377 	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
378 		dev_warn(&client->dev,
379 			"This driver is known to work with "
380 			"firmware version %hu,\n", RADIO_FW_VERSION);
381 		dev_warn(&client->dev,
382 			"but the device has firmware version %hu.\n",
383 			radio->registers[CHIPID] & CHIPID_FIRMWARE);
384 		version_warning = 1;
385 	}
386 
387 	/* give out version warning */
388 	if (version_warning == 1) {
389 		dev_warn(&client->dev,
390 			"If you have some trouble using this driver,\n");
391 		dev_warn(&client->dev,
392 			"please report to V4L ML at "
393 			"linux-media@vger.kernel.org\n");
394 	}
395 
396 	/* set initial frequency */
397 	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
398 
399 	/* rds buffer allocation */
400 	radio->buf_size = rds_buf * 3;
401 	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
402 	if (!radio->buffer) {
403 		retval = -EIO;
404 		goto err_radio;
405 	}
406 
407 	/* rds buffer configuration */
408 	radio->wr_index = 0;
409 	radio->rd_index = 0;
410 	init_waitqueue_head(&radio->read_queue);
411 
412 	retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
413 			IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
414 	if (retval) {
415 		dev_err(&client->dev, "Failed to register interrupt\n");
416 		goto err_rds;
417 	}
418 
419 	/* register video device */
420 	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
421 			radio_nr);
422 	if (retval) {
423 		dev_warn(&client->dev, "Could not register video device\n");
424 		goto err_all;
425 	}
426 	i2c_set_clientdata(client, radio);
427 
428 	return 0;
429 err_all:
430 	free_irq(client->irq, radio);
431 err_rds:
432 	kfree(radio->buffer);
433 err_radio:
434 	kfree(radio);
435 err_initial:
436 	return retval;
437 }
438 
439 
440 /*
441  * si470x_i2c_remove - remove the device
442  */
443 static __devexit int si470x_i2c_remove(struct i2c_client *client)
444 {
445 	struct si470x_device *radio = i2c_get_clientdata(client);
446 
447 	free_irq(client->irq, radio);
448 	video_unregister_device(&radio->videodev);
449 	kfree(radio);
450 
451 	return 0;
452 }
453 
454 
455 #ifdef CONFIG_PM
456 /*
457  * si470x_i2c_suspend - suspend the device
458  */
459 static int si470x_i2c_suspend(struct device *dev)
460 {
461 	struct i2c_client *client = to_i2c_client(dev);
462 	struct si470x_device *radio = i2c_get_clientdata(client);
463 
464 	/* power down */
465 	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
466 	if (si470x_set_register(radio, POWERCFG) < 0)
467 		return -EIO;
468 
469 	return 0;
470 }
471 
472 
473 /*
474  * si470x_i2c_resume - resume the device
475  */
476 static int si470x_i2c_resume(struct device *dev)
477 {
478 	struct i2c_client *client = to_i2c_client(dev);
479 	struct si470x_device *radio = i2c_get_clientdata(client);
480 
481 	/* power up : need 110ms */
482 	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
483 	if (si470x_set_register(radio, POWERCFG) < 0)
484 		return -EIO;
485 	msleep(110);
486 
487 	return 0;
488 }
489 
490 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
491 #endif
492 
493 
494 /*
495  * si470x_i2c_driver - i2c driver interface
496  */
497 static struct i2c_driver si470x_i2c_driver = {
498 	.driver = {
499 		.name		= "si470x",
500 		.owner		= THIS_MODULE,
501 #ifdef CONFIG_PM
502 		.pm		= &si470x_i2c_pm,
503 #endif
504 	},
505 	.probe			= si470x_i2c_probe,
506 	.remove			= __devexit_p(si470x_i2c_remove),
507 	.id_table		= si470x_i2c_id,
508 };
509 
510 module_i2c_driver(si470x_i2c_driver);
511 
512 MODULE_LICENSE("GPL");
513 MODULE_AUTHOR(DRIVER_AUTHOR);
514 MODULE_DESCRIPTION(DRIVER_DESC);
515 MODULE_VERSION(DRIVER_VERSION);
516