1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * drivers/media/radio/si470x/radio-si470x-i2c.c
4 *
5 * I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
6 *
7 * Copyright (c) 2009 Samsung Electronics Co.Ltd
8 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
9 */
10
11
12/* driver definitions */
13#define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
14#define DRIVER_CARD "Silicon Labs Si470x FM Radio"
15#define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
16#define DRIVER_VERSION "1.0.2"
17
18/* kernel includes */
19#include <linux/i2c.h>
20#include <linux/slab.h>
21#include <linux/delay.h>
22#include <linux/gpio/consumer.h>
23#include <linux/interrupt.h>
24
25#include "radio-si470x.h"
26
27
28/* I2C Device ID List */
29static const struct i2c_device_id si470x_i2c_id[] = {
30 /* Generic Entry */
31 { "si470x", 0 },
32 /* Terminating entry */
33 { }
34};
35MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
36
37
38/**************************************************************************
39 * Module Parameters
40 **************************************************************************/
41
42/* Radio Nr */
43static int radio_nr = -1;
44module_param(radio_nr, int, 0444);
45MODULE_PARM_DESC(radio_nr, "Radio Nr");
46
47/* RDS buffer blocks */
48static unsigned int rds_buf = 100;
49module_param(rds_buf, uint, 0444);
50MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
51
52/* RDS maximum block errors */
53static unsigned short max_rds_errors = 1;
54/* 0 means 0 errors requiring correction */
55/* 1 means 1-2 errors requiring correction (used by original USBRadio.exe) */
56/* 2 means 3-5 errors requiring correction */
57/* 3 means 6+ errors or errors in checkword, correction not possible */
58module_param(max_rds_errors, ushort, 0644);
59MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
60
61
62
63/**************************************************************************
64 * I2C Definitions
65 **************************************************************************/
66
67/* Write starts with the upper byte of register 0x02 */
68#define WRITE_REG_NUM 8
69#define WRITE_INDEX(i) (i + 0x02)
70
71/* Read starts with the upper byte of register 0x0a */
72#define READ_REG_NUM RADIO_REGISTER_NUM
73#define READ_INDEX(i) ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
74
75
76
77/**************************************************************************
78 * General Driver Functions - REGISTERs
79 **************************************************************************/
80
81/*
82 * si470x_get_register - read register
83 */
84static int si470x_get_register(struct si470x_device *radio, int regnr)
85{
86 __be16 buf[READ_REG_NUM];
87 struct i2c_msg msgs[1] = {
88 {
89 .addr = radio->client->addr,
90 .flags = I2C_M_RD,
91 .len = sizeof(u16) * READ_REG_NUM,
92 .buf = (void *)buf
93 },
94 };
95
96 if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1)
97 return -EIO;
98
99 radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
100
101 return 0;
102}
103
104
105/*
106 * si470x_set_register - write register
107 */
108static int si470x_set_register(struct si470x_device *radio, int regnr)
109{
110 int i;
111 __be16 buf[WRITE_REG_NUM];
112 struct i2c_msg msgs[1] = {
113 {
114 .addr = radio->client->addr,
115 .len = sizeof(u16) * WRITE_REG_NUM,
116 .buf = (void *)buf
117 },
118 };
119
120 for (i = 0; i < WRITE_REG_NUM; i++)
121 buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
122
123 if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1)
124 return -EIO;
125
126 return 0;
127}
128
129
130
131/**************************************************************************
132 * General Driver Functions - ENTIRE REGISTERS
133 **************************************************************************/
134
135/*
136 * si470x_get_all_registers - read entire registers
137 */
138static int si470x_get_all_registers(struct si470x_device *radio)
139{
140 int i;
141 __be16 buf[READ_REG_NUM];
142 struct i2c_msg msgs[1] = {
143 {
144 .addr = radio->client->addr,
145 .flags = I2C_M_RD,
146 .len = sizeof(u16) * READ_REG_NUM,
147 .buf = (void *)buf
148 },
149 };
150
151 if (i2c_transfer(adap: radio->client->adapter, msgs, num: 1) != 1)
152 return -EIO;
153
154 for (i = 0; i < READ_REG_NUM; i++)
155 radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
156
157 return 0;
158}
159
160
161
162/**************************************************************************
163 * File Operations Interface
164 **************************************************************************/
165
166/*
167 * si470x_fops_open - file open
168 */
169static int si470x_fops_open(struct file *file)
170{
171 struct si470x_device *radio = video_drvdata(file);
172 int retval = v4l2_fh_open(filp: file);
173
174 if (retval)
175 return retval;
176
177 if (v4l2_fh_is_singular_file(filp: file)) {
178 /* start radio */
179 retval = si470x_start(radio);
180 if (retval < 0)
181 goto done;
182
183 /* enable RDS / STC interrupt */
184 radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
185 radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
186 radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
187 radio->registers[SYSCONFIG1] |= 0x1 << 2;
188 retval = si470x_set_register(radio, SYSCONFIG1);
189 }
190
191done:
192 if (retval)
193 v4l2_fh_release(filp: file);
194 return retval;
195}
196
197
198/*
199 * si470x_fops_release - file release
200 */
201static int si470x_fops_release(struct file *file)
202{
203 struct si470x_device *radio = video_drvdata(file);
204
205 if (v4l2_fh_is_singular_file(filp: file))
206 /* stop radio */
207 si470x_stop(radio);
208
209 return v4l2_fh_release(filp: file);
210}
211
212
213
214/**************************************************************************
215 * Video4Linux Interface
216 **************************************************************************/
217
218/*
219 * si470x_vidioc_querycap - query device capabilities
220 */
221static int si470x_vidioc_querycap(struct file *file, void *priv,
222 struct v4l2_capability *capability)
223{
224 strscpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
225 strscpy(capability->card, DRIVER_CARD, sizeof(capability->card));
226 return 0;
227}
228
229
230
231/**************************************************************************
232 * I2C Interface
233 **************************************************************************/
234
235/*
236 * si470x_i2c_interrupt - interrupt handler
237 */
238static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
239{
240 struct si470x_device *radio = dev_id;
241 unsigned char regnr;
242 unsigned char blocknum;
243 unsigned short bler; /* rds block errors */
244 unsigned short rds;
245 unsigned char tmpbuf[3];
246 int retval = 0;
247
248 /* check Seek/Tune Complete */
249 retval = si470x_get_register(radio, STATUSRSSI);
250 if (retval < 0)
251 goto end;
252
253 if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
254 complete(&radio->completion);
255
256 /* safety checks */
257 if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
258 goto end;
259
260 /* Update RDS registers */
261 for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
262 retval = si470x_get_register(radio, STATUSRSSI + regnr);
263 if (retval < 0)
264 goto end;
265 }
266
267 /* get rds blocks */
268 if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
269 /* No RDS group ready, better luck next time */
270 goto end;
271
272 for (blocknum = 0; blocknum < 4; blocknum++) {
273 switch (blocknum) {
274 default:
275 bler = (radio->registers[STATUSRSSI] &
276 STATUSRSSI_BLERA) >> 9;
277 rds = radio->registers[RDSA];
278 break;
279 case 1:
280 bler = (radio->registers[READCHAN] &
281 READCHAN_BLERB) >> 14;
282 rds = radio->registers[RDSB];
283 break;
284 case 2:
285 bler = (radio->registers[READCHAN] &
286 READCHAN_BLERC) >> 12;
287 rds = radio->registers[RDSC];
288 break;
289 case 3:
290 bler = (radio->registers[READCHAN] &
291 READCHAN_BLERD) >> 10;
292 rds = radio->registers[RDSD];
293 break;
294 }
295
296 /* Fill the V4L2 RDS buffer */
297 put_unaligned_le16(val: rds, p: &tmpbuf);
298 tmpbuf[2] = blocknum; /* offset name */
299 tmpbuf[2] |= blocknum << 3; /* received offset */
300 if (bler > max_rds_errors)
301 tmpbuf[2] |= 0x80; /* uncorrectable errors */
302 else if (bler > 0)
303 tmpbuf[2] |= 0x40; /* corrected error(s) */
304
305 /* copy RDS block to internal buffer */
306 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
307 radio->wr_index += 3;
308
309 /* wrap write pointer */
310 if (radio->wr_index >= radio->buf_size)
311 radio->wr_index = 0;
312
313 /* check for overflow */
314 if (radio->wr_index == radio->rd_index) {
315 /* increment and wrap read pointer */
316 radio->rd_index += 3;
317 if (radio->rd_index >= radio->buf_size)
318 radio->rd_index = 0;
319 }
320 }
321
322 if (radio->wr_index != radio->rd_index)
323 wake_up_interruptible(&radio->read_queue);
324
325end:
326 return IRQ_HANDLED;
327}
328
329
330/*
331 * si470x_i2c_probe - probe for the device
332 */
333static int si470x_i2c_probe(struct i2c_client *client)
334{
335 struct si470x_device *radio;
336 int retval = 0;
337
338 /* private data allocation and initialization */
339 radio = devm_kzalloc(dev: &client->dev, size: sizeof(*radio), GFP_KERNEL);
340 if (!radio) {
341 retval = -ENOMEM;
342 goto err_initial;
343 }
344
345 radio->client = client;
346 radio->band = 1; /* Default to 76 - 108 MHz */
347 mutex_init(&radio->lock);
348 init_completion(x: &radio->completion);
349
350 radio->get_register = si470x_get_register;
351 radio->set_register = si470x_set_register;
352 radio->fops_open = si470x_fops_open;
353 radio->fops_release = si470x_fops_release;
354 radio->vidioc_querycap = si470x_vidioc_querycap;
355
356 retval = v4l2_device_register(dev: &client->dev, v4l2_dev: &radio->v4l2_dev);
357 if (retval < 0) {
358 dev_err(&client->dev, "couldn't register v4l2_device\n");
359 goto err_initial;
360 }
361
362 v4l2_ctrl_handler_init(&radio->hdl, 2);
363 v4l2_ctrl_new_std(hdl: &radio->hdl, ops: &si470x_ctrl_ops,
364 V4L2_CID_AUDIO_MUTE, min: 0, max: 1, step: 1, def: 1);
365 v4l2_ctrl_new_std(hdl: &radio->hdl, ops: &si470x_ctrl_ops,
366 V4L2_CID_AUDIO_VOLUME, min: 0, max: 15, step: 1, def: 15);
367 if (radio->hdl.error) {
368 retval = radio->hdl.error;
369 dev_err(&client->dev, "couldn't register control\n");
370 goto err_all;
371 }
372
373 /* video device initialization */
374 radio->videodev = si470x_viddev_template;
375 radio->videodev.ctrl_handler = &radio->hdl;
376 radio->videodev.lock = &radio->lock;
377 radio->videodev.v4l2_dev = &radio->v4l2_dev;
378 radio->videodev.release = video_device_release_empty;
379 radio->videodev.device_caps =
380 V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | V4L2_CAP_TUNER |
381 V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
382 video_set_drvdata(vdev: &radio->videodev, data: radio);
383
384 radio->gpio_reset = devm_gpiod_get_optional(dev: &client->dev, con_id: "reset",
385 flags: GPIOD_OUT_LOW);
386 if (IS_ERR(ptr: radio->gpio_reset)) {
387 retval = PTR_ERR(ptr: radio->gpio_reset);
388 dev_err(&client->dev, "Failed to request gpio: %d\n", retval);
389 goto err_all;
390 }
391
392 if (radio->gpio_reset)
393 gpiod_set_value(desc: radio->gpio_reset, value: 1);
394
395 /* power up : need 110ms */
396 radio->registers[POWERCFG] = POWERCFG_ENABLE;
397 if (si470x_set_register(radio, POWERCFG) < 0) {
398 retval = -EIO;
399 goto err_all;
400 }
401 msleep(msecs: 110);
402
403 /* get device and chip versions */
404 if (si470x_get_all_registers(radio) < 0) {
405 retval = -EIO;
406 goto err_all;
407 }
408 dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
409 radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
410 if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
411 dev_warn(&client->dev,
412 "This driver is known to work with firmware version %u, but the device has firmware version %u.\n"
413 "If you have some trouble using this driver, please report to V4L ML at linux-media@vger.kernel.org\n",
414 RADIO_FW_VERSION,
415 radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
416 }
417
418 /* set initial frequency */
419 si470x_set_freq(radio, freq: 87.5 * FREQ_MUL); /* available in all regions */
420
421 /* rds buffer allocation */
422 radio->buf_size = rds_buf * 3;
423 radio->buffer = devm_kmalloc(dev: &client->dev, size: radio->buf_size, GFP_KERNEL);
424 if (!radio->buffer) {
425 retval = -EIO;
426 goto err_all;
427 }
428
429 /* rds buffer configuration */
430 radio->wr_index = 0;
431 radio->rd_index = 0;
432 init_waitqueue_head(&radio->read_queue);
433
434 retval = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, NULL,
435 thread_fn: si470x_i2c_interrupt,
436 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
437 DRIVER_NAME, dev_id: radio);
438 if (retval) {
439 dev_err(&client->dev, "Failed to register interrupt\n");
440 goto err_all;
441 }
442
443 /* register video device */
444 retval = video_register_device(vdev: &radio->videodev, type: VFL_TYPE_RADIO,
445 nr: radio_nr);
446 if (retval) {
447 dev_warn(&client->dev, "Could not register video device\n");
448 goto err_all;
449 }
450 i2c_set_clientdata(client, data: radio);
451
452 return 0;
453err_all:
454 v4l2_ctrl_handler_free(hdl: &radio->hdl);
455 v4l2_device_unregister(v4l2_dev: &radio->v4l2_dev);
456err_initial:
457 return retval;
458}
459
460
461/*
462 * si470x_i2c_remove - remove the device
463 */
464static void si470x_i2c_remove(struct i2c_client *client)
465{
466 struct si470x_device *radio = i2c_get_clientdata(client);
467
468 video_unregister_device(vdev: &radio->videodev);
469
470 if (radio->gpio_reset)
471 gpiod_set_value(desc: radio->gpio_reset, value: 0);
472
473 v4l2_ctrl_handler_free(hdl: &radio->hdl);
474 v4l2_device_unregister(v4l2_dev: &radio->v4l2_dev);
475}
476
477
478#ifdef CONFIG_PM_SLEEP
479/*
480 * si470x_i2c_suspend - suspend the device
481 */
482static int si470x_i2c_suspend(struct device *dev)
483{
484 struct i2c_client *client = to_i2c_client(dev);
485 struct si470x_device *radio = i2c_get_clientdata(client);
486
487 /* power down */
488 radio->registers[POWERCFG] |= POWERCFG_DISABLE;
489 if (si470x_set_register(radio, POWERCFG) < 0)
490 return -EIO;
491
492 return 0;
493}
494
495
496/*
497 * si470x_i2c_resume - resume the device
498 */
499static int si470x_i2c_resume(struct device *dev)
500{
501 struct i2c_client *client = to_i2c_client(dev);
502 struct si470x_device *radio = i2c_get_clientdata(client);
503
504 /* power up : need 110ms */
505 radio->registers[POWERCFG] |= POWERCFG_ENABLE;
506 if (si470x_set_register(radio, POWERCFG) < 0)
507 return -EIO;
508 msleep(msecs: 110);
509
510 return 0;
511}
512
513static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
514#endif
515
516#if IS_ENABLED(CONFIG_OF)
517static const struct of_device_id si470x_of_match[] = {
518 { .compatible = "silabs,si470x" },
519 { },
520};
521MODULE_DEVICE_TABLE(of, si470x_of_match);
522#endif
523
524/*
525 * si470x_i2c_driver - i2c driver interface
526 */
527static struct i2c_driver si470x_i2c_driver = {
528 .driver = {
529 .name = "si470x",
530 .of_match_table = of_match_ptr(si470x_of_match),
531#ifdef CONFIG_PM_SLEEP
532 .pm = &si470x_i2c_pm,
533#endif
534 },
535 .probe = si470x_i2c_probe,
536 .remove = si470x_i2c_remove,
537 .id_table = si470x_i2c_id,
538};
539
540module_i2c_driver(si470x_i2c_driver);
541
542MODULE_LICENSE("GPL");
543MODULE_AUTHOR(DRIVER_AUTHOR);
544MODULE_DESCRIPTION(DRIVER_DESC);
545MODULE_VERSION(DRIVER_VERSION);
546

source code of linux/drivers/media/radio/si470x/radio-si470x-i2c.c