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 		{
102 			.addr = radio->client->addr,
103 			.flags = I2C_M_RD,
104 			.len = sizeof(u16) * READ_REG_NUM,
105 			.buf = (void *)buf
106 		},
107 	};
108 
109 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
110 		return -EIO;
111 
112 	radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
113 
114 	return 0;
115 }
116 
117 
118 /*
119  * si470x_set_register - write register
120  */
121 int si470x_set_register(struct si470x_device *radio, int regnr)
122 {
123 	int i;
124 	u16 buf[WRITE_REG_NUM];
125 	struct i2c_msg msgs[1] = {
126 		{
127 			.addr = radio->client->addr,
128 			.len = sizeof(u16) * WRITE_REG_NUM,
129 			.buf = (void *)buf
130 		},
131 	};
132 
133 	for (i = 0; i < WRITE_REG_NUM; i++)
134 		buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
135 
136 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
137 		return -EIO;
138 
139 	return 0;
140 }
141 
142 
143 
144 /**************************************************************************
145  * General Driver Functions - ENTIRE REGISTERS
146  **************************************************************************/
147 
148 /*
149  * si470x_get_all_registers - read entire registers
150  */
151 static int si470x_get_all_registers(struct si470x_device *radio)
152 {
153 	int i;
154 	u16 buf[READ_REG_NUM];
155 	struct i2c_msg msgs[1] = {
156 		{
157 			.addr = radio->client->addr,
158 			.flags = I2C_M_RD,
159 			.len = sizeof(u16) * READ_REG_NUM,
160 			.buf = (void *)buf
161 		},
162 	};
163 
164 	if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
165 		return -EIO;
166 
167 	for (i = 0; i < READ_REG_NUM; i++)
168 		radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
169 
170 	return 0;
171 }
172 
173 
174 
175 /**************************************************************************
176  * File Operations Interface
177  **************************************************************************/
178 
179 /*
180  * si470x_fops_open - file open
181  */
182 int si470x_fops_open(struct file *file)
183 {
184 	struct si470x_device *radio = video_drvdata(file);
185 	int retval = v4l2_fh_open(file);
186 
187 	if (retval)
188 		return retval;
189 
190 	if (v4l2_fh_is_singular_file(file)) {
191 		/* start radio */
192 		retval = si470x_start(radio);
193 		if (retval < 0)
194 			goto done;
195 
196 		/* enable RDS / STC interrupt */
197 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
198 		radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
199 		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
200 		radio->registers[SYSCONFIG1] |= 0x1 << 2;
201 		retval = si470x_set_register(radio, SYSCONFIG1);
202 	}
203 
204 done:
205 	if (retval)
206 		v4l2_fh_release(file);
207 	return retval;
208 }
209 
210 
211 /*
212  * si470x_fops_release - file release
213  */
214 int si470x_fops_release(struct file *file)
215 {
216 	struct si470x_device *radio = video_drvdata(file);
217 
218 	if (v4l2_fh_is_singular_file(file))
219 		/* stop radio */
220 		si470x_stop(radio);
221 
222 	return v4l2_fh_release(file);
223 }
224 
225 
226 
227 /**************************************************************************
228  * Video4Linux Interface
229  **************************************************************************/
230 
231 /*
232  * si470x_vidioc_querycap - query device capabilities
233  */
234 int si470x_vidioc_querycap(struct file *file, void *priv,
235 		struct v4l2_capability *capability)
236 {
237 	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
238 	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
239 	capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
240 		V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
241 	capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
242 
243 	return 0;
244 }
245 
246 
247 
248 /**************************************************************************
249  * I2C Interface
250  **************************************************************************/
251 
252 /*
253  * si470x_i2c_interrupt - interrupt handler
254  */
255 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
256 {
257 	struct si470x_device *radio = dev_id;
258 	unsigned char regnr;
259 	unsigned char blocknum;
260 	unsigned short bler; /* rds block errors */
261 	unsigned short rds;
262 	unsigned char tmpbuf[3];
263 	int retval = 0;
264 
265 	/* check Seek/Tune Complete */
266 	retval = si470x_get_register(radio, STATUSRSSI);
267 	if (retval < 0)
268 		goto end;
269 
270 	if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
271 		complete(&radio->completion);
272 
273 	/* safety checks */
274 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
275 		goto end;
276 
277 	/* Update RDS registers */
278 	for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
279 		retval = si470x_get_register(radio, STATUSRSSI + regnr);
280 		if (retval < 0)
281 			goto end;
282 	}
283 
284 	/* get rds blocks */
285 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
286 		/* No RDS group ready, better luck next time */
287 		goto end;
288 
289 	for (blocknum = 0; blocknum < 4; blocknum++) {
290 		switch (blocknum) {
291 		default:
292 			bler = (radio->registers[STATUSRSSI] &
293 					STATUSRSSI_BLERA) >> 9;
294 			rds = radio->registers[RDSA];
295 			break;
296 		case 1:
297 			bler = (radio->registers[READCHAN] &
298 					READCHAN_BLERB) >> 14;
299 			rds = radio->registers[RDSB];
300 			break;
301 		case 2:
302 			bler = (radio->registers[READCHAN] &
303 					READCHAN_BLERC) >> 12;
304 			rds = radio->registers[RDSC];
305 			break;
306 		case 3:
307 			bler = (radio->registers[READCHAN] &
308 					READCHAN_BLERD) >> 10;
309 			rds = radio->registers[RDSD];
310 			break;
311 		}
312 
313 		/* Fill the V4L2 RDS buffer */
314 		put_unaligned_le16(rds, &tmpbuf);
315 		tmpbuf[2] = blocknum;		/* offset name */
316 		tmpbuf[2] |= blocknum << 3;	/* received offset */
317 		if (bler > max_rds_errors)
318 			tmpbuf[2] |= 0x80;	/* uncorrectable errors */
319 		else if (bler > 0)
320 			tmpbuf[2] |= 0x40;	/* corrected error(s) */
321 
322 		/* copy RDS block to internal buffer */
323 		memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
324 		radio->wr_index += 3;
325 
326 		/* wrap write pointer */
327 		if (radio->wr_index >= radio->buf_size)
328 			radio->wr_index = 0;
329 
330 		/* check for overflow */
331 		if (radio->wr_index == radio->rd_index) {
332 			/* increment and wrap read pointer */
333 			radio->rd_index += 3;
334 			if (radio->rd_index >= radio->buf_size)
335 				radio->rd_index = 0;
336 		}
337 	}
338 
339 	if (radio->wr_index != radio->rd_index)
340 		wake_up_interruptible(&radio->read_queue);
341 
342 end:
343 	return IRQ_HANDLED;
344 }
345 
346 
347 /*
348  * si470x_i2c_probe - probe for the device
349  */
350 static int si470x_i2c_probe(struct i2c_client *client,
351 			    const struct i2c_device_id *id)
352 {
353 	struct si470x_device *radio;
354 	int retval = 0;
355 	unsigned char version_warning = 0;
356 
357 	/* private data allocation and initialization */
358 	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
359 	if (!radio) {
360 		retval = -ENOMEM;
361 		goto err_initial;
362 	}
363 
364 	radio->client = client;
365 	radio->band = 1; /* Default to 76 - 108 MHz */
366 	mutex_init(&radio->lock);
367 	init_completion(&radio->completion);
368 
369 	/* video device initialization */
370 	radio->videodev = si470x_viddev_template;
371 	video_set_drvdata(&radio->videodev, radio);
372 
373 	/* power up : need 110ms */
374 	radio->registers[POWERCFG] = POWERCFG_ENABLE;
375 	if (si470x_set_register(radio, POWERCFG) < 0) {
376 		retval = -EIO;
377 		goto err_radio;
378 	}
379 	msleep(110);
380 
381 	/* get device and chip versions */
382 	if (si470x_get_all_registers(radio) < 0) {
383 		retval = -EIO;
384 		goto err_radio;
385 	}
386 	dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
387 			radio->registers[DEVICEID], radio->registers[CHIPID]);
388 	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
389 		dev_warn(&client->dev,
390 			"This driver is known to work with "
391 			"firmware version %hu,\n", RADIO_FW_VERSION);
392 		dev_warn(&client->dev,
393 			"but the device has firmware version %hu.\n",
394 			radio->registers[CHIPID] & CHIPID_FIRMWARE);
395 		version_warning = 1;
396 	}
397 
398 	/* give out version warning */
399 	if (version_warning == 1) {
400 		dev_warn(&client->dev,
401 			"If you have some trouble using this driver,\n");
402 		dev_warn(&client->dev,
403 			"please report to V4L ML at "
404 			"linux-media@vger.kernel.org\n");
405 	}
406 
407 	/* set initial frequency */
408 	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
409 
410 	/* rds buffer allocation */
411 	radio->buf_size = rds_buf * 3;
412 	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
413 	if (!radio->buffer) {
414 		retval = -EIO;
415 		goto err_radio;
416 	}
417 
418 	/* rds buffer configuration */
419 	radio->wr_index = 0;
420 	radio->rd_index = 0;
421 	init_waitqueue_head(&radio->read_queue);
422 
423 	retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt,
424 			IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
425 	if (retval) {
426 		dev_err(&client->dev, "Failed to register interrupt\n");
427 		goto err_rds;
428 	}
429 
430 	/* register video device */
431 	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
432 			radio_nr);
433 	if (retval) {
434 		dev_warn(&client->dev, "Could not register video device\n");
435 		goto err_all;
436 	}
437 	i2c_set_clientdata(client, radio);
438 
439 	return 0;
440 err_all:
441 	free_irq(client->irq, radio);
442 err_rds:
443 	kfree(radio->buffer);
444 err_radio:
445 	kfree(radio);
446 err_initial:
447 	return retval;
448 }
449 
450 
451 /*
452  * si470x_i2c_remove - remove the device
453  */
454 static int si470x_i2c_remove(struct i2c_client *client)
455 {
456 	struct si470x_device *radio = i2c_get_clientdata(client);
457 
458 	free_irq(client->irq, radio);
459 	video_unregister_device(&radio->videodev);
460 	kfree(radio);
461 
462 	return 0;
463 }
464 
465 
466 #ifdef CONFIG_PM_SLEEP
467 /*
468  * si470x_i2c_suspend - suspend the device
469  */
470 static int si470x_i2c_suspend(struct device *dev)
471 {
472 	struct i2c_client *client = to_i2c_client(dev);
473 	struct si470x_device *radio = i2c_get_clientdata(client);
474 
475 	/* power down */
476 	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
477 	if (si470x_set_register(radio, POWERCFG) < 0)
478 		return -EIO;
479 
480 	return 0;
481 }
482 
483 
484 /*
485  * si470x_i2c_resume - resume the device
486  */
487 static int si470x_i2c_resume(struct device *dev)
488 {
489 	struct i2c_client *client = to_i2c_client(dev);
490 	struct si470x_device *radio = i2c_get_clientdata(client);
491 
492 	/* power up : need 110ms */
493 	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
494 	if (si470x_set_register(radio, POWERCFG) < 0)
495 		return -EIO;
496 	msleep(110);
497 
498 	return 0;
499 }
500 
501 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
502 #endif
503 
504 
505 /*
506  * si470x_i2c_driver - i2c driver interface
507  */
508 static struct i2c_driver si470x_i2c_driver = {
509 	.driver = {
510 		.name		= "si470x",
511 		.owner		= THIS_MODULE,
512 #ifdef CONFIG_PM_SLEEP
513 		.pm		= &si470x_i2c_pm,
514 #endif
515 	},
516 	.probe			= si470x_i2c_probe,
517 	.remove			= si470x_i2c_remove,
518 	.id_table		= si470x_i2c_id,
519 };
520 
521 module_i2c_driver(si470x_i2c_driver);
522 
523 MODULE_LICENSE("GPL");
524 MODULE_AUTHOR(DRIVER_AUTHOR);
525 MODULE_DESCRIPTION(DRIVER_DESC);
526 MODULE_VERSION(DRIVER_VERSION);
527