2 * drivers/media/radio/si470x/radio-si470x-i2c.c
4 * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
6 * Copyright (c) 2009 Samsung Electronics Co.Ltd
7 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
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.
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.
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
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"
33 #include <linux/i2c.h>
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/interrupt.h>
38 #include "radio-si470x.h"
41 /* I2C Device ID List */
42 static const struct i2c_device_id si470x_i2c_id[] = {
45 /* Terminating entry */
48 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
52 /**************************************************************************
54 **************************************************************************/
57 static int radio_nr = -1;
58 module_param(radio_nr, int, 0444);
59 MODULE_PARM_DESC(radio_nr, "Radio Nr");
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*");
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*");
77 /**************************************************************************
79 **************************************************************************/
81 /* Write starts with the upper byte of register 0x02 */
82 #define WRITE_REG_NUM 8
83 #define WRITE_INDEX(i) (i + 0x02)
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)
91 /**************************************************************************
92 * General Driver Functions - REGISTERs
93 **************************************************************************/
96 * si470x_get_register - read register
98 int si470x_get_register(struct si470x_device *radio, int regnr)
100 u16 buf[READ_REG_NUM];
101 struct i2c_msg msgs[1] = {
102 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
106 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
109 radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
116 * si470x_set_register - write register
118 int si470x_set_register(struct si470x_device *radio, int regnr)
121 u16 buf[WRITE_REG_NUM];
122 struct i2c_msg msgs[1] = {
123 { radio->client->addr, 0, sizeof(u16) * WRITE_REG_NUM,
127 for (i = 0; i < WRITE_REG_NUM; i++)
128 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
130 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
138 /**************************************************************************
139 * General Driver Functions - ENTIRE REGISTERS
140 **************************************************************************/
143 * si470x_get_all_registers - read entire registers
145 static int si470x_get_all_registers(struct si470x_device *radio)
148 u16 buf[READ_REG_NUM];
149 struct i2c_msg msgs[1] = {
150 { radio->client->addr, I2C_M_RD, sizeof(u16) * READ_REG_NUM,
154 if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
157 for (i = 0; i < READ_REG_NUM; i++)
158 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
165 /**************************************************************************
166 * General Driver Functions - DISCONNECT_CHECK
167 **************************************************************************/
170 * si470x_disconnect_check - check whether radio disconnects
172 int si470x_disconnect_check(struct si470x_device *radio)
179 /**************************************************************************
180 * File Operations Interface
181 **************************************************************************/
184 * si470x_fops_open - file open
186 int si470x_fops_open(struct file *file)
188 struct si470x_device *radio = video_drvdata(file);
191 mutex_lock(&radio->lock);
194 if (radio->users == 1) {
196 retval = si470x_start(radio);
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);
208 mutex_unlock(&radio->lock);
214 * si470x_fops_release - file release
216 int si470x_fops_release(struct file *file)
218 struct si470x_device *radio = video_drvdata(file);
225 mutex_lock(&radio->lock);
227 if (radio->users == 0)
229 retval = si470x_stop(radio);
231 mutex_unlock(&radio->lock);
238 /**************************************************************************
239 * Video4Linux Interface
240 **************************************************************************/
243 * si470x_vidioc_querycap - query device capabilities
245 int si470x_vidioc_querycap(struct file *file, void *priv,
246 struct v4l2_capability *capability)
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;
259 /**************************************************************************
261 **************************************************************************/
264 * si470x_i2c_interrupt_work - rds processing function
266 static void si470x_i2c_interrupt_work(struct work_struct *work)
268 struct si470x_device *radio = container_of(work,
269 struct si470x_device, radio_work);
271 unsigned char blocknum;
272 unsigned short bler; /* rds block errors */
274 unsigned char tmpbuf[3];
278 if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
281 /* Update RDS registers */
282 for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++) {
283 retval = si470x_get_register(radio, STATUSRSSI + regnr);
289 if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
290 /* No RDS group ready, better luck next time */
293 for (blocknum = 0; blocknum < 4; blocknum++) {
296 bler = (radio->registers[STATUSRSSI] &
297 STATUSRSSI_BLERA) >> 9;
298 rds = radio->registers[RDSA];
301 bler = (radio->registers[READCHAN] &
302 READCHAN_BLERB) >> 14;
303 rds = radio->registers[RDSB];
306 bler = (radio->registers[READCHAN] &
307 READCHAN_BLERC) >> 12;
308 rds = radio->registers[RDSC];
311 bler = (radio->registers[READCHAN] &
312 READCHAN_BLERD) >> 10;
313 rds = radio->registers[RDSD];
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 */
324 tmpbuf[2] |= 0x40; /* corrected error(s) */
326 /* copy RDS block to internal buffer */
327 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
328 radio->wr_index += 3;
330 /* wrap write pointer */
331 if (radio->wr_index >= radio->buf_size)
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)
343 if (radio->wr_index != radio->rd_index)
344 wake_up_interruptible(&radio->read_queue);
349 * si470x_i2c_interrupt - interrupt handler
351 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
353 struct si470x_device *radio = dev_id;
355 if (!work_pending(&radio->radio_work))
356 schedule_work(&radio->radio_work);
363 * si470x_i2c_probe - probe for the device
365 static int __devinit si470x_i2c_probe(struct i2c_client *client,
366 const struct i2c_device_id *id)
368 struct si470x_device *radio;
370 unsigned char version_warning = 0;
372 /* private data allocation and initialization */
373 radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
379 INIT_WORK(&radio->radio_work, si470x_i2c_interrupt_work);
381 radio->client = client;
382 mutex_init(&radio->lock);
384 /* video device allocation and initialization */
385 radio->videodev = video_device_alloc();
386 if (!radio->videodev) {
390 memcpy(radio->videodev, &si470x_viddev_template,
391 sizeof(si470x_viddev_template));
392 video_set_drvdata(radio->videodev, radio);
394 /* power up : need 110ms */
395 radio->registers[POWERCFG] = POWERCFG_ENABLE;
396 if (si470x_set_register(radio, POWERCFG) < 0) {
402 /* get device and chip versions */
403 if (si470x_get_all_registers(radio) < 0) {
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);
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");
428 /* set initial frequency */
429 si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
431 /* rds buffer allocation */
432 radio->buf_size = rds_buf * 3;
433 radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
434 if (!radio->buffer) {
439 /* rds buffer configuration */
442 init_waitqueue_head(&radio->read_queue);
444 retval = request_irq(client->irq, si470x_i2c_interrupt,
445 IRQF_TRIGGER_FALLING, DRIVER_NAME, radio);
447 dev_err(&client->dev, "Failed to register interrupt\n");
451 /* register video device */
452 retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
455 dev_warn(&client->dev, "Could not register video device\n");
458 i2c_set_clientdata(client, radio);
462 free_irq(client->irq, radio);
464 kfree(radio->buffer);
466 video_device_release(radio->videodev);
475 * si470x_i2c_remove - remove the device
477 static __devexit int si470x_i2c_remove(struct i2c_client *client)
479 struct si470x_device *radio = i2c_get_clientdata(client);
481 free_irq(client->irq, radio);
482 cancel_work_sync(&radio->radio_work);
483 video_unregister_device(radio->videodev);
485 i2c_set_clientdata(client, NULL);
493 * si470x_i2c_suspend - suspend the device
495 static int si470x_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
497 struct si470x_device *radio = i2c_get_clientdata(client);
500 radio->registers[POWERCFG] |= POWERCFG_DISABLE;
501 if (si470x_set_register(radio, POWERCFG) < 0)
509 * si470x_i2c_resume - resume the device
511 static int si470x_i2c_resume(struct i2c_client *client)
513 struct si470x_device *radio = i2c_get_clientdata(client);
515 /* power up : need 110ms */
516 radio->registers[POWERCFG] |= POWERCFG_ENABLE;
517 if (si470x_set_register(radio, POWERCFG) < 0)
524 #define si470x_i2c_suspend NULL
525 #define si470x_i2c_resume NULL
530 * si470x_i2c_driver - i2c driver interface
532 static struct i2c_driver si470x_i2c_driver = {
535 .owner = THIS_MODULE,
537 .probe = si470x_i2c_probe,
538 .remove = __devexit_p(si470x_i2c_remove),
539 .suspend = si470x_i2c_suspend,
540 .resume = si470x_i2c_resume,
541 .id_table = si470x_i2c_id,
546 /**************************************************************************
548 **************************************************************************/
551 * si470x_i2c_init - module init
553 static int __init si470x_i2c_init(void)
555 printk(KERN_INFO DRIVER_DESC ", Version " DRIVER_VERSION "\n");
556 return i2c_add_driver(&si470x_i2c_driver);
561 * si470x_i2c_exit - module exit
563 static void __exit si470x_i2c_exit(void)
565 i2c_del_driver(&si470x_i2c_driver);
569 module_init(si470x_i2c_init);
570 module_exit(si470x_i2c_exit);
572 MODULE_LICENSE("GPL");
573 MODULE_AUTHOR(DRIVER_AUTHOR);
574 MODULE_DESCRIPTION(DRIVER_DESC);
575 MODULE_VERSION(DRIVER_VERSION);