root/drivers/media/radio/si4713/radio-usb-si4713.c

DEFINITIONS

1. to_si4713_dev
2. vidioc_querycap
3. vidioc_g_modulator
4. vidioc_s_modulator
5. vidioc_s_frequency
6. vidioc_g_frequency
7. usb_si4713_video_device_release
8. si4713_send_startup_command
9. si4713_start_seq
10. send_command
11. si4713_i2c_read
12. si4713_i2c_write
13. si4713_transfer
14. si4713_functionality
15. si4713_register_i2c_adapter
16. usb_si4713_probe
17. usb_si4713_disconnect

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates.
   4  * All rights reserved.
   5  */
   6 
   7 /* kernel includes */
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/usb.h>
  11 #include <linux/init.h>
  12 #include <linux/slab.h>
  13 #include <linux/input.h>
  14 #include <linux/mutex.h>
  15 #include <linux/i2c.h>
  16 /* V4l includes */
  17 #include <linux/videodev2.h>
  18 #include <media/v4l2-common.h>
  19 #include <media/v4l2-device.h>
  20 #include <media/v4l2-ioctl.h>
  21 #include <media/v4l2-event.h>
  22 #include <linux/platform_data/media/si4713.h>
  23 
  24 #include "si4713.h"
  25 
  26 /* driver and module definitions */
  27 MODULE_AUTHOR("Dinesh Ram <dinesh.ram@cern.ch>");
  28 MODULE_DESCRIPTION("Si4713 FM Transmitter USB driver");
  29 MODULE_LICENSE("GPL v2");
  30 
  31 /* The Device announces itself as Cygnal Integrated Products, Inc. */
  32 #define USB_SI4713_VENDOR               0x10c4
  33 #define USB_SI4713_PRODUCT              0x8244
  34 
  35 #define BUFFER_LENGTH                   64
  36 #define USB_TIMEOUT                     1000
  37 #define USB_RESP_TIMEOUT                50000
  38 
  39 /* USB Device ID List */
  40 static const struct usb_device_id usb_si4713_usb_device_table[] = {
  41         {USB_DEVICE_AND_INTERFACE_INFO(USB_SI4713_VENDOR, USB_SI4713_PRODUCT,
  42                                                         USB_CLASS_HID, 0, 0) },
  43         { }                                             /* Terminating entry */
  44 };
  45 
  46 MODULE_DEVICE_TABLE(usb, usb_si4713_usb_device_table);
  47 
  48 struct si4713_usb_device {
  49         struct usb_device       *usbdev;
  50         struct usb_interface    *intf;
  51         struct video_device     vdev;
  52         struct v4l2_device      v4l2_dev;
  53         struct v4l2_subdev      *v4l2_subdev;
  54         struct mutex            lock;
  55         struct i2c_adapter      i2c_adapter;
  56 
  57         u8                      *buffer;
  58 };
  59 
  60 static inline struct si4713_usb_device *to_si4713_dev(struct v4l2_device *v4l2_dev)
  61 {
  62         return container_of(v4l2_dev, struct si4713_usb_device, v4l2_dev);
  63 }
  64 
  65 static int vidioc_querycap(struct file *file, void *priv,
  66                                         struct v4l2_capability *v)
  67 {
  68         struct si4713_usb_device *radio = video_drvdata(file);
  69 
  70         strscpy(v->driver, "radio-usb-si4713", sizeof(v->driver));
  71         strscpy(v->card, "Si4713 FM Transmitter", sizeof(v->card));
  72         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
  73         return 0;
  74 }
  75 
  76 static int vidioc_g_modulator(struct file *file, void *priv,
  77                                 struct v4l2_modulator *vm)
  78 {
  79         struct si4713_usb_device *radio = video_drvdata(file);
  80 
  81         return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_modulator, vm);
  82 }
  83 
  84 static int vidioc_s_modulator(struct file *file, void *priv,
  85                                 const struct v4l2_modulator *vm)
  86 {
  87         struct si4713_usb_device *radio = video_drvdata(file);
  88 
  89         return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_modulator, vm);
  90 }
  91 
  92 static int vidioc_s_frequency(struct file *file, void *priv,
  93                                 const struct v4l2_frequency *vf)
  94 {
  95         struct si4713_usb_device *radio = video_drvdata(file);
  96 
  97         return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_frequency, vf);
  98 }
  99 
 100 static int vidioc_g_frequency(struct file *file, void *priv,
 101                                 struct v4l2_frequency *vf)
 102 {
 103         struct si4713_usb_device *radio = video_drvdata(file);
 104 
 105         return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_frequency, vf);
 106 }
 107 
 108 static const struct v4l2_ioctl_ops usb_si4713_ioctl_ops = {
 109         .vidioc_querycap          = vidioc_querycap,
 110         .vidioc_g_modulator       = vidioc_g_modulator,
 111         .vidioc_s_modulator       = vidioc_s_modulator,
 112         .vidioc_g_frequency       = vidioc_g_frequency,
 113         .vidioc_s_frequency       = vidioc_s_frequency,
 114         .vidioc_log_status        = v4l2_ctrl_log_status,
 115         .vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
 116         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 117 };
 118 
 119 /* File system interface */
 120 static const struct v4l2_file_operations usb_si4713_fops = {
 121         .owner          = THIS_MODULE,
 122         .open           = v4l2_fh_open,
 123         .release        = v4l2_fh_release,
 124         .poll           = v4l2_ctrl_poll,
 125         .unlocked_ioctl = video_ioctl2,
 126 };
 127 
 128 static void usb_si4713_video_device_release(struct v4l2_device *v4l2_dev)
 129 {
 130         struct si4713_usb_device *radio = to_si4713_dev(v4l2_dev);
 131         struct i2c_adapter *adapter = &radio->i2c_adapter;
 132 
 133         i2c_del_adapter(adapter);
 134         v4l2_device_unregister(&radio->v4l2_dev);
 135         kfree(radio->buffer);
 136         kfree(radio);
 137 }
 138 
 139 /*
 140  * This command sequence emulates the behaviour of the Windows driver.
 141  * The structure of these commands was determined by sniffing the
 142  * usb traffic of the device during startup.
 143  * Most likely, these commands make some queries to the device.
 144  * Commands are sent to enquire parameters like the bus mode,
 145  * component revision, boot mode, the device serial number etc.
 146  *
 147  * These commands are necessary to be sent in this order during startup.
 148  * The device fails to powerup if these commands are not sent.
 149  *
 150  * The complete list of startup commands is given in the start_seq table below.
 151  */
 152 static int si4713_send_startup_command(struct si4713_usb_device *radio)
 153 {
 154         unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
 155         u8 *buffer = radio->buffer;
 156         int retval;
 157 
 158         /* send the command */
 159         retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 160                                         0x09, 0x21, 0x033f, 0, radio->buffer,
 161                                         BUFFER_LENGTH, USB_TIMEOUT);
 162         if (retval < 0)
 163                 return retval;
 164 
 165         for (;;) {
 166                 /* receive the response */
 167                 retval = usb_control_msg(radio->usbdev, usb_rcvctrlpipe(radio->usbdev, 0),
 168                                 0x01, 0xa1, 0x033f, 0, radio->buffer,
 169                                 BUFFER_LENGTH, USB_TIMEOUT);
 170                 if (retval < 0)
 171                         return retval;
 172                 if (!radio->buffer[1]) {
 173                         /* USB traffic sniffing showed that some commands require
 174                          * additional checks. */
 175                         switch (buffer[1]) {
 176                         case 0x32:
 177                                 if (radio->buffer[2] == 0)
 178                                         return 0;
 179                                 break;
 180                         case 0x14:
 181                         case 0x12:
 182                                 if (radio->buffer[2] & SI4713_CTS)
 183                                         return 0;
 184                                 break;
 185                         case 0x06:
 186                                 if ((radio->buffer[2] & SI4713_CTS) && radio->buffer[9] == 0x08)
 187                                         return 0;
 188                                 break;
 189                         default:
 190                                 return 0;
 191                         }
 192                 }
 193                 if (time_is_before_jiffies(until_jiffies))
 194                         return -EIO;
 195                 msleep(3);
 196         }
 197 
 198         return retval;
 199 }
 200 
 201 struct si4713_start_seq_table {
 202         int len;
 203         u8 payload[8];
 204 };
 205 
 206 /*
 207  * Some of the startup commands that could be recognized are :
 208  * (0x03): Get serial number of the board (Response : CB000-00-00)
 209  * (0x06, 0x03, 0x03, 0x08, 0x01, 0x0f) : Get Component revision
 210  */
 211 static const struct si4713_start_seq_table start_seq[] = {
 212 
 213         { 1, { 0x03 } },
 214         { 2, { 0x32, 0x7f } },
 215         { 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
 216         { 2, { 0x14, 0x02 } },
 217         { 2, { 0x09, 0x90 } },
 218         { 3, { 0x08, 0x90, 0xfa } },
 219         { 2, { 0x36, 0x01 } },
 220         { 2, { 0x05, 0x03 } },
 221         { 7, { 0x06, 0x00, 0x06, 0x0e, 0x01, 0x0f, 0x05 } },
 222         { 1, { 0x12 } },
 223         /* Commands that are sent after pressing the 'Initialize'
 224                 button in the windows application */
 225         { 1, { 0x03 } },
 226         { 1, { 0x01 } },
 227         { 2, { 0x09, 0x90 } },
 228         { 3, { 0x08, 0x90, 0xfa } },
 229         { 1, { 0x34 } },
 230         { 2, { 0x35, 0x01 } },
 231         { 2, { 0x36, 0x01 } },
 232         { 2, { 0x30, 0x09 } },
 233         { 4, { 0x30, 0x06, 0x00, 0xe2 } },
 234         { 3, { 0x31, 0x01, 0x30 } },
 235         { 3, { 0x31, 0x04, 0x09 } },
 236         { 2, { 0x05, 0x02 } },
 237         { 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
 238 };
 239 
 240 static int si4713_start_seq(struct si4713_usb_device *radio)
 241 {
 242         int retval = 0;
 243         int i;
 244 
 245         radio->buffer[0] = 0x3f;
 246 
 247         for (i = 0; i < ARRAY_SIZE(start_seq); i++) {
 248                 int len = start_seq[i].len;
 249                 const u8 *payload = start_seq[i].payload;
 250 
 251                 memcpy(radio->buffer + 1, payload, len);
 252                 memset(radio->buffer + len + 1, 0, BUFFER_LENGTH - 1 - len);
 253                 retval = si4713_send_startup_command(radio);
 254         }
 255 
 256         return retval;
 257 }
 258 
 259 static struct i2c_board_info si4713_board_info = {
 260         I2C_BOARD_INFO("si4713", SI4713_I2C_ADDR_BUSEN_HIGH),
 261 };
 262 
 263 struct si4713_command_table {
 264         int command_id;
 265         u8 payload[8];
 266 };
 267 
 268 /*
 269  * Structure of a command :
 270  *      Byte 1 : 0x3f (always)
 271  *      Byte 2 : 0x06 (send a command)
 272  *      Byte 3 : Unknown
 273  *      Byte 4 : Number of arguments + 1 (for the command byte)
 274  *      Byte 5 : Number of response bytes
 275  */
 276 static struct si4713_command_table command_table[] = {
 277 
 278         { SI4713_CMD_POWER_UP,          { 0x00, SI4713_PWUP_NARGS + 1, SI4713_PWUP_NRESP} },
 279         { SI4713_CMD_GET_REV,           { 0x03, 0x01, SI4713_GETREV_NRESP } },
 280         { SI4713_CMD_POWER_DOWN,        { 0x00, 0x01, SI4713_PWDN_NRESP} },
 281         { SI4713_CMD_SET_PROPERTY,      { 0x00, SI4713_SET_PROP_NARGS + 1, SI4713_SET_PROP_NRESP } },
 282         { SI4713_CMD_GET_PROPERTY,      { 0x00, SI4713_GET_PROP_NARGS + 1, SI4713_GET_PROP_NRESP } },
 283         { SI4713_CMD_TX_TUNE_FREQ,      { 0x03, SI4713_TXFREQ_NARGS + 1, SI4713_TXFREQ_NRESP } },
 284         { SI4713_CMD_TX_TUNE_POWER,     { 0x03, SI4713_TXPWR_NARGS + 1, SI4713_TXPWR_NRESP } },
 285         { SI4713_CMD_TX_TUNE_MEASURE,   { 0x03, SI4713_TXMEA_NARGS + 1, SI4713_TXMEA_NRESP } },
 286         { SI4713_CMD_TX_TUNE_STATUS,    { 0x00, SI4713_TXSTATUS_NARGS + 1, SI4713_TXSTATUS_NRESP } },
 287         { SI4713_CMD_TX_ASQ_STATUS,     { 0x03, SI4713_ASQSTATUS_NARGS + 1, SI4713_ASQSTATUS_NRESP } },
 288         { SI4713_CMD_GET_INT_STATUS,    { 0x03, 0x01, SI4713_GET_STATUS_NRESP } },
 289         { SI4713_CMD_TX_RDS_BUFF,       { 0x03, SI4713_RDSBUFF_NARGS + 1, SI4713_RDSBUFF_NRESP } },
 290         { SI4713_CMD_TX_RDS_PS,         { 0x00, SI4713_RDSPS_NARGS + 1, SI4713_RDSPS_NRESP } },
 291 };
 292 
 293 static int send_command(struct si4713_usb_device *radio, u8 *payload, char *data, int len)
 294 {
 295         int retval;
 296 
 297         radio->buffer[0] = 0x3f;
 298         radio->buffer[1] = 0x06;
 299 
 300         memcpy(radio->buffer + 2, payload, 3);
 301         memcpy(radio->buffer + 5, data, len);
 302         memset(radio->buffer + 5 + len, 0, BUFFER_LENGTH - 5 - len);
 303 
 304         /* send the command */
 305         retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 306                                         0x09, 0x21, 0x033f, 0, radio->buffer,
 307                                         BUFFER_LENGTH, USB_TIMEOUT);
 308 
 309         return retval < 0 ? retval : 0;
 310 }
 311 
 312 static int si4713_i2c_read(struct si4713_usb_device *radio, char *data, int len)
 313 {
 314         unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
 315         int retval;
 316 
 317         /* receive the response */
 318         for (;;) {
 319                 retval = usb_control_msg(radio->usbdev,
 320                                         usb_rcvctrlpipe(radio->usbdev, 0),
 321                                         0x01, 0xa1, 0x033f, 0, radio->buffer,
 322                                         BUFFER_LENGTH, USB_TIMEOUT);
 323                 if (retval < 0)
 324                         return retval;
 325 
 326                 /*
 327                  * Check that we get a valid reply back (buffer[1] == 0) and
 328                  * that CTS is set before returning, otherwise we wait and try
 329                  * again. The i2c driver also does the CTS check, but the timeouts
 330                  * used there are much too small for this USB driver, so we wait
 331                  * for it here.
 332                  */
 333                 if (radio->buffer[1] == 0 && (radio->buffer[2] & SI4713_CTS)) {
 334                         memcpy(data, radio->buffer + 2, len);
 335                         return 0;
 336                 }
 337                 if (time_is_before_jiffies(until_jiffies)) {
 338                         /* Zero the status value, ensuring CTS isn't set */
 339                         data[0] = 0;
 340                         return 0;
 341                 }
 342                 msleep(3);
 343         }
 344 }
 345 
 346 static int si4713_i2c_write(struct si4713_usb_device *radio, char *data, int len)
 347 {
 348         int retval = -EINVAL;
 349         int i;
 350 
 351         if (len > BUFFER_LENGTH - 5)
 352                 return -EINVAL;
 353 
 354         for (i = 0; i < ARRAY_SIZE(command_table); i++) {
 355                 if (data[0] == command_table[i].command_id)
 356                         retval = send_command(radio, command_table[i].payload,
 357                                                 data, len);
 358         }
 359 
 360         return retval < 0 ? retval : 0;
 361 }
 362 
 363 static int si4713_transfer(struct i2c_adapter *i2c_adapter,
 364                                 struct i2c_msg *msgs, int num)
 365 {
 366         struct si4713_usb_device *radio = i2c_get_adapdata(i2c_adapter);
 367         int retval = -EINVAL;
 368         int i;
 369 
 370         for (i = 0; i < num; i++) {
 371                 if (msgs[i].flags & I2C_M_RD)
 372                         retval = si4713_i2c_read(radio, msgs[i].buf, msgs[i].len);
 373                 else
 374                         retval = si4713_i2c_write(radio, msgs[i].buf, msgs[i].len);
 375                 if (retval)
 376                         break;
 377         }
 378 
 379         return retval ? retval : num;
 380 }
 381 
 382 static u32 si4713_functionality(struct i2c_adapter *adapter)
 383 {
 384         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 385 }
 386 
 387 static const struct i2c_algorithm si4713_algo = {
 388         .master_xfer   = si4713_transfer,
 389         .functionality = si4713_functionality,
 390 };
 391 
 392 /* This name value shows up in the sysfs filename associated
 393                 with this I2C adapter */
 394 static const struct i2c_adapter si4713_i2c_adapter_template = {
 395         .name   = "si4713-i2c",
 396         .owner  = THIS_MODULE,
 397         .algo   = &si4713_algo,
 398 };
 399 
 400 static int si4713_register_i2c_adapter(struct si4713_usb_device *radio)
 401 {
 402         radio->i2c_adapter = si4713_i2c_adapter_template;
 403         /* set up sysfs linkage to our parent device */
 404         radio->i2c_adapter.dev.parent = &radio->usbdev->dev;
 405         i2c_set_adapdata(&radio->i2c_adapter, radio);
 406 
 407         return i2c_add_adapter(&radio->i2c_adapter);
 408 }
 409 
 410 /* check if the device is present and register with v4l and usb if it is */
 411 static int usb_si4713_probe(struct usb_interface *intf,
 412                                 const struct usb_device_id *id)
 413 {
 414         struct si4713_usb_device *radio;
 415         struct i2c_adapter *adapter;
 416         struct v4l2_subdev *sd;
 417         int retval = -ENOMEM;
 418 
 419         dev_info(&intf->dev, "Si4713 development board discovered: (%04X:%04X)\n",
 420                         id->idVendor, id->idProduct);
 421 
 422         /* Initialize local device structure */
 423         radio = kzalloc(sizeof(struct si4713_usb_device), GFP_KERNEL);
 424         if (radio)
 425                 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 426 
 427         if (!radio || !radio->buffer) {
 428                 dev_err(&intf->dev, "kmalloc for si4713_usb_device failed\n");
 429                 kfree(radio);
 430                 return -ENOMEM;
 431         }
 432 
 433         mutex_init(&radio->lock);
 434 
 435         radio->usbdev = interface_to_usbdev(intf);
 436         radio->intf = intf;
 437         usb_set_intfdata(intf, &radio->v4l2_dev);
 438 
 439         retval = si4713_start_seq(radio);
 440         if (retval < 0)
 441                 goto err_v4l2;
 442 
 443         retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 444         if (retval < 0) {
 445                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 446                 goto err_v4l2;
 447         }
 448 
 449         retval = si4713_register_i2c_adapter(radio);
 450         if (retval < 0) {
 451                 dev_err(&intf->dev, "could not register i2c device\n");
 452                 goto err_i2cdev;
 453         }
 454 
 455         adapter = &radio->i2c_adapter;
 456         sd = v4l2_i2c_new_subdev_board(&radio->v4l2_dev, adapter,
 457                                           &si4713_board_info, NULL);
 458         radio->v4l2_subdev = sd;
 459         if (!sd) {
 460                 dev_err(&intf->dev, "cannot get v4l2 subdevice\n");
 461                 retval = -ENODEV;
 462                 goto del_adapter;
 463         }
 464 
 465         radio->vdev.ctrl_handler = sd->ctrl_handler;
 466         radio->v4l2_dev.release = usb_si4713_video_device_release;
 467         strscpy(radio->vdev.name, radio->v4l2_dev.name,
 468                 sizeof(radio->vdev.name));
 469         radio->vdev.v4l2_dev = &radio->v4l2_dev;
 470         radio->vdev.fops = &usb_si4713_fops;
 471         radio->vdev.ioctl_ops = &usb_si4713_ioctl_ops;
 472         radio->vdev.lock = &radio->lock;
 473         radio->vdev.release = video_device_release_empty;
 474         radio->vdev.vfl_dir = VFL_DIR_TX;
 475         radio->vdev.device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
 476 
 477         video_set_drvdata(&radio->vdev, radio);
 478 
 479         retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
 480         if (retval < 0) {
 481                 dev_err(&intf->dev, "could not register video device\n");
 482                 goto del_adapter;
 483         }
 484 
 485         dev_info(&intf->dev, "V4L2 device registered as %s\n",
 486                         video_device_node_name(&radio->vdev));
 487 
 488         return 0;
 489 
 490 del_adapter:
 491         i2c_del_adapter(adapter);
 492 err_i2cdev:
 493         v4l2_device_unregister(&radio->v4l2_dev);
 494 err_v4l2:
 495         kfree(radio->buffer);
 496         kfree(radio);
 497         return retval;
 498 }
 499 
 500 static void usb_si4713_disconnect(struct usb_interface *intf)
 501 {
 502         struct si4713_usb_device *radio = to_si4713_dev(usb_get_intfdata(intf));
 503 
 504         dev_info(&intf->dev, "Si4713 development board now disconnected\n");
 505 
 506         mutex_lock(&radio->lock);
 507         usb_set_intfdata(intf, NULL);
 508         video_unregister_device(&radio->vdev);
 509         v4l2_device_disconnect(&radio->v4l2_dev);
 510         mutex_unlock(&radio->lock);
 511         v4l2_device_put(&radio->v4l2_dev);
 512 }
 513 
 514 /* USB subsystem interface */
 515 static struct usb_driver usb_si4713_driver = {
 516         .name                   = "radio-usb-si4713",
 517         .probe                  = usb_si4713_probe,
 518         .disconnect             = usb_si4713_disconnect,
 519         .id_table               = usb_si4713_usb_device_table,
 520 };
 521 
 522 module_usb_driver(usb_si4713_driver);