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 Receiver"
  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         capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
 227                 V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
 228         capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
 229
 230         return 0;
 231 }
 232
 233
 234
 235 /**************************************************************************
 236  * I2C Interface
 237  **************************************************************************/
 238
 239 /*
 240  * si470x_i2c_interrupt - interrupt handler
 241  */
 242 static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
 243 {
 244         struct si470x_device *radio = dev_id;
 245         unsigned char regnr;
 246         unsigned char blocknum;
 247         unsigned short bler; /* rds block errors */
 248         unsigned short rds;
 249         unsigned char tmpbuf[3];
 250         int retval = 0;
 251
 252         /* check Seek/Tune Complete */
 253         retval = si470x_get_register(radio, STATUSRSSI);
 254         if (retval < 0)
 255                 goto end;
 256
 257         if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
 258                 complete(&radio->completion);
 259
 260         /* safety checks */
 261         if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
 262                 goto end;
 263
 264         /* Update RDS registers */
 265         for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
 266                 retval = si470x_get_register(radio, STATUSRSSI + regnr);
 267                 if (retval < 0)
 268                         goto end;
 269         }
 270
 271         /* get rds blocks */
 272         if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
 273                 /* No RDS group ready, better luck next time */
 274                 goto end;
 275
 276         for (blocknum = 0; blocknum < 4; blocknum++) {
 277                 switch (blocknum) {
 278                 default:
 279                         bler = (radio->registers[STATUSRSSI] &
 280                                         STATUSRSSI_BLERA) >> 9;
 281                         rds = radio->registers[RDSA];
 282                         break;
 283                 case 1:
 284                         bler = (radio->registers[READCHAN] &
 285                                         READCHAN_BLERB) >> 14;
 286                         rds = radio->registers[RDSB];
 287                         break;
 288                 case 2:
 289                         bler = (radio->registers[READCHAN] &
 290                                         READCHAN_BLERC) >> 12;
 291                         rds = radio->registers[RDSC];
 292                         break;
 293                 case 3:
 294                         bler = (radio->registers[READCHAN] &
 295                                         READCHAN_BLERD) >> 10;
 296                         rds = radio->registers[RDSD];
 297                         break;
 298                 }
 299
 300                 /* Fill the V4L2 RDS buffer */
 301                 put_unaligned_le16(rds, &tmpbuf);
 302                 tmpbuf[2] = blocknum;           /* offset name */
 303                 tmpbuf[2] |= blocknum << 3;     /* received offset */
 304                 if (bler > max_rds_errors)
 305                         tmpbuf[2] |= 0x80;      /* uncorrectable errors */
 306                 else if (bler > 0)
 307                         tmpbuf[2] |= 0x40;      /* corrected error(s) */
 308
 309                 /* copy RDS block to internal buffer */
 310                 memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
 311                 radio->wr_index += 3;
 312
 313                 /* wrap write pointer */
 314                 if (radio->wr_index >= radio->buf_size)
 315                         radio->wr_index = 0;
 316
 317                 /* check for overflow */
 318                 if (radio->wr_index == radio->rd_index) {
 319                         /* increment and wrap read pointer */
 320                         radio->rd_index += 3;
 321                         if (radio->rd_index >= radio->buf_size)
 322                                 radio->rd_index = 0;
 323                 }
 324         }
 325
 326         if (radio->wr_index != radio->rd_index)
 327                 wake_up_interruptible(&radio->read_queue);
 328
 329 end:
 330         return IRQ_HANDLED;
 331 }
 332
 333
 334 /*
 335  * si470x_i2c_probe - probe for the device
 336  */
 337 static int si470x_i2c_probe(struct i2c_client *client,
 338                             const struct i2c_device_id *id)
 339 {
 340         struct si470x_device *radio;
 341         int retval = 0;
 342         unsigned char version_warning = 0;
 343
 344         /* private data allocation and initialization */
 345         radio = devm_kzalloc(&client->dev, sizeof(*radio), GFP_KERNEL);
 346         if (!radio) {
 347                 retval = -ENOMEM;
 348                 goto err_initial;
 349         }
 350
 351         radio->client = client;
 352         radio->band = 1; /* Default to 76 - 108 MHz */
 353         mutex_init(&radio->lock);
 354         init_completion(&radio->completion);
 355
 356         radio->get_register = si470x_get_register;
 357         radio->set_register = si470x_set_register;
 358         radio->fops_open = si470x_fops_open;
 359         radio->fops_release = si470x_fops_release;
 360         radio->vidioc_querycap = si470x_vidioc_querycap;
 361
 362         retval = v4l2_device_register(&client->dev, &radio->v4l2_dev);
 363         if (retval < 0) {
 364                 dev_err(&client->dev, "couldn't register v4l2_device\n");
 365                 goto err_initial;
 366         }
 367
 368         v4l2_ctrl_handler_init(&radio->hdl, 2);
 369         v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
 370                         V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 371         v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
 372                         V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
 373         if (radio->hdl.error) {
 374                 retval = radio->hdl.error;
 375                 dev_err(&client->dev, "couldn't register control\n");
 376                 goto err_dev;
 377         }
 378
 379         /* video device initialization */
 380         radio->videodev = si470x_viddev_template;
 381         radio->videodev.ctrl_handler = &radio->hdl;
 382         radio->videodev.lock = &radio->lock;
 383         radio->videodev.v4l2_dev = &radio->v4l2_dev;
 384         radio->videodev.release = video_device_release_empty;
 385         video_set_drvdata(&radio->videodev, radio);
 386
 387         radio->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
 388                                                     GPIOD_OUT_LOW);
 389         if (IS_ERR(radio->gpio_reset)) {
 390                 retval = PTR_ERR(radio->gpio_reset);
 391                 dev_err(&client->dev, "Failed to request gpio: %d\n", retval);
 392                 goto err_all;
 393         }
 394
 395         if (radio->gpio_reset)
 396                 gpiod_set_value(radio->gpio_reset, 1);
 397
 398         /* power up : need 110ms */
 399         radio->registers[POWERCFG] = POWERCFG_ENABLE;
 400         if (si470x_set_register(radio, POWERCFG) < 0) {
 401                 retval = -EIO;
 402                 goto err_all;
 403         }
 404         msleep(110);
 405
 406         /* get device and chip versions */
 407         if (si470x_get_all_registers(radio) < 0) {
 408                 retval = -EIO;
 409                 goto err_all;
 410         }
 411         dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
 412                         radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
 413         if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
 414                 dev_warn(&client->dev,
 415                         "This driver is known to work with firmware version %hu,\n",
 416                         RADIO_FW_VERSION);
 417                 dev_warn(&client->dev,
 418                         "but the device has firmware version %hu.\n",
 419                         radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
 420                 version_warning = 1;
 421         }
 422
 423         /* give out version warning */
 424         if (version_warning == 1) {
 425                 dev_warn(&client->dev,
 426                         "If you have some trouble using this driver,\n");
 427                 dev_warn(&client->dev,
 428                         "please report to V4L ML at linux-media@vger.kernel.org\n");
 429         }
 430
 431         /* set initial frequency */
 432         si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
 433
 434         /* rds buffer allocation */
 435         radio->buf_size = rds_buf * 3;
 436         radio->buffer = devm_kmalloc(&client->dev, radio->buf_size, GFP_KERNEL);
 437         if (!radio->buffer) {
 438                 retval = -EIO;
 439                 goto err_all;
 440         }
 441
 442         /* rds buffer configuration */
 443         radio->wr_index = 0;
 444         radio->rd_index = 0;
 445         init_waitqueue_head(&radio->read_queue);
 446
 447         retval = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 448                                            si470x_i2c_interrupt,
 449                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 450                                            DRIVER_NAME, radio);
 451         if (retval) {
 452                 dev_err(&client->dev, "Failed to register interrupt\n");
 453                 goto err_all;
 454         }
 455
 456         /* register video device */
 457         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 458                         radio_nr);
 459         if (retval) {
 460                 dev_warn(&client->dev, "Could not register video device\n");
 461                 goto err_all;
 462         }
 463         i2c_set_clientdata(client, radio);
 464
 465         return 0;
 466 err_all:
 467         v4l2_ctrl_handler_free(&radio->hdl);
 468 err_dev:
 469         v4l2_device_unregister(&radio->v4l2_dev);
 470 err_initial:
 471         return retval;
 472 }
 473
 474
 475 /*
 476  * si470x_i2c_remove - remove the device
 477  */
 478 static int si470x_i2c_remove(struct i2c_client *client)
 479 {
 480         struct si470x_device *radio = i2c_get_clientdata(client);
 481
 482         video_unregister_device(&radio->videodev);
 483
 484         if (radio->gpio_reset)
 485                 gpiod_set_value(radio->gpio_reset, 0);
 486
 487         return 0;
 488 }
 489
 490
 491 #ifdef CONFIG_PM_SLEEP
 492 /*
 493  * si470x_i2c_suspend - suspend the device
 494  */
 495 static int si470x_i2c_suspend(struct device *dev)
 496 {
 497         struct i2c_client *client = to_i2c_client(dev);
 498         struct si470x_device *radio = i2c_get_clientdata(client);
 499
 500         /* power down */
 501         radio->registers[POWERCFG] |= POWERCFG_DISABLE;
 502         if (si470x_set_register(radio, POWERCFG) < 0)
 503                 return -EIO;
 504
 505         return 0;
 506 }
 507
 508
 509 /*
 510  * si470x_i2c_resume - resume the device
 511  */
 512 static int si470x_i2c_resume(struct device *dev)
 513 {
 514         struct i2c_client *client = to_i2c_client(dev);
 515         struct si470x_device *radio = i2c_get_clientdata(client);
 516
 517         /* power up : need 110ms */
 518         radio->registers[POWERCFG] |= POWERCFG_ENABLE;
 519         if (si470x_set_register(radio, POWERCFG) < 0)
 520                 return -EIO;
 521         msleep(110);
 522
 523         return 0;
 524 }
 525
 526 static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
 527 #endif
 528
 529 #if IS_ENABLED(CONFIG_OF)
 530 static const struct of_device_id si470x_of_match[] = {
 531         { .compatible = "silabs,si470x" },
 532         { },
 533 };
 534 MODULE_DEVICE_TABLE(of, si470x_of_match);
 535 #endif
 536
 537 /*
 538  * si470x_i2c_driver - i2c driver interface
 539  */
 540 static struct i2c_driver si470x_i2c_driver = {
 541         .driver = {
 542                 .name           = "si470x",
 543                 .of_match_table = of_match_ptr(si470x_of_match),
 544 #ifdef CONFIG_PM_SLEEP
 545                 .pm             = &si470x_i2c_pm,
 546 #endif
 547         },
 548         .probe                  = si470x_i2c_probe,
 549         .remove                 = si470x_i2c_remove,
 550         .id_table               = si470x_i2c_id,
 551 };
 552
 553 module_i2c_driver(si470x_i2c_driver);
 554
 555 MODULE_LICENSE("GPL");
 556 MODULE_AUTHOR(DRIVER_AUTHOR);
 557 MODULE_DESCRIPTION(DRIVER_DESC);
 558 MODULE_VERSION(DRIVER_VERSION);