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 */
41static const struct i2c_device_id si470x_i2c_id[] = {
42	/* Generic Entry */
43	{ "si470x", 0 },
44	/* Terminating entry */
45	{ }
46};
47MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
48
49
50
51/**************************************************************************
52 * Module Parameters
53 **************************************************************************/
54
55/* Radio Nr */
56static int radio_nr = -1;
57module_param(radio_nr, int, 0444);
58MODULE_PARM_DESC(radio_nr, "Radio Nr");
59
60/* RDS buffer blocks */
61static unsigned int rds_buf = 100;
62module_param(rds_buf, uint, 0444);
63MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
64
65/* RDS maximum block errors */
66static 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 */
71module_param(max_rds_errors, ushort, 0644);
72MODULE_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 */
97int 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 */
121int 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 */
151static 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 */
182int 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
204done:
205	if (retval)
206		v4l2_fh_release(file);
207	return retval;
208}
209
210
211/*
212 * si470x_fops_release - file release
213 */
214int 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 */
234int 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 */
255static 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
342end:
343	return IRQ_HANDLED;
344}
345
346
347/*
348 * si470x_i2c_probe - probe for the device
349 */
350static 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[SI_CHIPID]);
388	if ((radio->registers[SI_CHIPID] & SI_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[SI_CHIPID] & SI_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 | IRQF_ONESHOT, DRIVER_NAME,
425			radio);
426	if (retval) {
427		dev_err(&client->dev, "Failed to register interrupt\n");
428		goto err_rds;
429	}
430
431	/* register video device */
432	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
433			radio_nr);
434	if (retval) {
435		dev_warn(&client->dev, "Could not register video device\n");
436		goto err_all;
437	}
438	i2c_set_clientdata(client, radio);
439
440	return 0;
441err_all:
442	free_irq(client->irq, radio);
443err_rds:
444	kfree(radio->buffer);
445err_radio:
446	kfree(radio);
447err_initial:
448	return retval;
449}
450
451
452/*
453 * si470x_i2c_remove - remove the device
454 */
455static int si470x_i2c_remove(struct i2c_client *client)
456{
457	struct si470x_device *radio = i2c_get_clientdata(client);
458
459	free_irq(client->irq, radio);
460	video_unregister_device(&radio->videodev);
461	kfree(radio);
462
463	return 0;
464}
465
466
467#ifdef CONFIG_PM_SLEEP
468/*
469 * si470x_i2c_suspend - suspend the device
470 */
471static int si470x_i2c_suspend(struct device *dev)
472{
473	struct i2c_client *client = to_i2c_client(dev);
474	struct si470x_device *radio = i2c_get_clientdata(client);
475
476	/* power down */
477	radio->registers[POWERCFG] |= POWERCFG_DISABLE;
478	if (si470x_set_register(radio, POWERCFG) < 0)
479		return -EIO;
480
481	return 0;
482}
483
484
485/*
486 * si470x_i2c_resume - resume the device
487 */
488static int si470x_i2c_resume(struct device *dev)
489{
490	struct i2c_client *client = to_i2c_client(dev);
491	struct si470x_device *radio = i2c_get_clientdata(client);
492
493	/* power up : need 110ms */
494	radio->registers[POWERCFG] |= POWERCFG_ENABLE;
495	if (si470x_set_register(radio, POWERCFG) < 0)
496		return -EIO;
497	msleep(110);
498
499	return 0;
500}
501
502static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
503#endif
504
505
506/*
507 * si470x_i2c_driver - i2c driver interface
508 */
509static struct i2c_driver si470x_i2c_driver = {
510	.driver = {
511		.name		= "si470x",
512		.owner		= THIS_MODULE,
513#ifdef CONFIG_PM_SLEEP
514		.pm		= &si470x_i2c_pm,
515#endif
516	},
517	.probe			= si470x_i2c_probe,
518	.remove			= si470x_i2c_remove,
519	.id_table		= si470x_i2c_id,
520};
521
522module_i2c_driver(si470x_i2c_driver);
523
524MODULE_LICENSE("GPL");
525MODULE_AUTHOR(DRIVER_AUTHOR);
526MODULE_DESCRIPTION(DRIVER_DESC);
527MODULE_VERSION(DRIVER_VERSION);
528