drivers/media/radio/si470x/radio-si470x-i2c.c

   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 */
  29 static const struct i2c_device_id si470x_i2c_id[] = {
  30         /* Generic Entry */
  31         { "si470x", 0 },
  32         /* Terminating entry */
  33         { }
  34 };
  35 MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
  36
  37
  38 /**************************************************************************
  39  * Module Parameters
  40  **************************************************************************/
  41
  42 /* Radio Nr */
  43 static int radio_nr = -1;
  44 module_param(radio_nr, int, 0444);
  45 MODULE_PARM_DESC(radio_nr, "Radio Nr");
  46
  47 /* RDS buffer blocks */
  48 static unsigned int rds_buf = 100;
  49 module_param(rds_buf, uint, 0444);
  50 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  51
  52 /* RDS maximum block errors */
  53 static 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 */
  58 module_param(max_rds_errors, ushort, 0644);
  59 MODULE_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  */
  84 static 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(radio->client->adapter, msgs, 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  */
 108 static 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(radio->client->adapter, msgs, 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  */
 138 static 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(radio->client->adapter, msgs, 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  */
 169 static int si470x_fops_open(struct file *file)
 170 {
 171         struct si470x_device *radio = video_drvdata(file);
 172         int retval = v4l2_fh_open(file);
 173
 174         if (retval)
 175                 return retval;
 176
 177         if (v4l2_fh_is_singular_file(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
 191 done:
 192         if (retval)
 193                 v4l2_fh_release(file);
 194         return retval;
 195 }
 196
 197
 198 /*
 199  * si470x_fops_release - file release
 200  */
 201 static int si470x_fops_release(struct file *file)
 202 {
 203         struct si470x_device *radio = video_drvdata(file);
 204
 205         if (v4l2_fh_is_singular_file(file))
 206                 /* stop radio */
 207                 si470x_stop(radio);
 208
 209         return v4l2_fh_release(file);
 210 }
 211
 212
 213
 214 /**************************************************************************
 215  * Video4Linux Interface
 216  **************************************************************************/
 217
 218 /*
 219  * si470x_vidioc_querycap - query device capabilities
 220  */
 221 static 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  */
 238 static 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(rds, &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
 325 end:
 326         return IRQ_HANDLED;
 327 }
 328
 329
 330 /*
 331  * si470x_i2c_probe - probe for the device
 332  */
 333 static 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(&client->dev, 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(&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(&client->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(&radio->hdl, &si470x_ctrl_ops,
 364                         V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 365         v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
 366                         V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 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(&radio->videodev, radio);
 383
 384         radio->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
 385                                                     GPIOD_OUT_LOW);
 386         if (IS_ERR(radio->gpio_reset)) {
 387                 retval = PTR_ERR(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(radio->gpio_reset, 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(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, 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(&client->dev, 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(&client->dev, client->irq, NULL,
 435                                            si470x_i2c_interrupt,
 436                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 437                                            DRIVER_NAME, 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(&radio->videodev, VFL_TYPE_RADIO,
 445                         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, radio);
 451
 452         return 0;
 453 err_all:
 454         v4l2_ctrl_handler_free(&radio->hdl);
 455         v4l2_device_unregister(&radio->v4l2_dev);
 456 err_initial:
 457         return retval;
 458 }
 459
 460
 461 /*
 462  * si470x_i2c_remove - remove the device
 463  */
 464 static void si470x_i2c_remove(struct i2c_client *client)
 465 {
 466         struct si470x_device *radio = i2c_get_clientdata(client);
 467
 468         video_unregister_device(&radio->videodev);
 469
 470         if (radio->gpio_reset)
 471                 gpiod_set_value(radio->gpio_reset, 0);
 472
 473         v4l2_ctrl_handler_free(&radio->hdl);
 474         v4l2_device_unregister(&radio->v4l2_dev);
 475 }
 476
 477
 478 #ifdef CONFIG_PM_SLEEP
 479 /*
 480  * si470x_i2c_suspend - suspend the device
 481  */
 482 static 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  */
 499 static 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(110);
 509
 510         return 0;
 511 }
 512
 513 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 514 #endif
 515
 516 #if IS_ENABLED(CONFIG_OF)
 517 static const struct of_device_id si470x_of_match[] = {
 518         { .compatible = "silabs,si470x" },
 519         { },
 520 };
 521 MODULE_DEVICE_TABLE(of, si470x_of_match);
 522 #endif
 523
 524 /*
 525  * si470x_i2c_driver - i2c driver interface
 526  */
 527 static 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
 540 module_i2c_driver(si470x_i2c_driver);
 541
 542 MODULE_LICENSE("GPL");
 543 MODULE_AUTHOR(DRIVER_AUTHOR);
 544 MODULE_DESCRIPTION(DRIVER_DESC);
 545 MODULE_VERSION(DRIVER_VERSION);