drivers/media/radio/radio-keene.c

   1 /*
   2  * Copyright (c) 2012 Hans Verkuil <hverkuil@xs4all.nl>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  */
  18
  19 /* kernel includes */
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/input.h>
  25 #include <linux/videodev2.h>
  26 #include <media/v4l2-device.h>
  27 #include <media/v4l2-ioctl.h>
  28 #include <media/v4l2-ctrls.h>
  29 #include <media/v4l2-event.h>
  30 #include <linux/usb.h>
  31 #include <linux/mutex.h>
  32
  33 /* driver and module definitions */
  34 MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
  35 MODULE_DESCRIPTION("Keene FM Transmitter driver");
  36 MODULE_LICENSE("GPL");
  37
  38 /* Actually, it advertises itself as a Logitech */
  39 #define USB_KEENE_VENDOR 0x046d
  40 #define USB_KEENE_PRODUCT 0x0a0e
  41
  42 /* Probably USB_TIMEOUT should be modified in module parameter */
  43 #define BUFFER_LENGTH 8
  44 #define USB_TIMEOUT 500
  45
  46 /* Frequency limits in MHz */
  47 #define FREQ_MIN  76U
  48 #define FREQ_MAX 108U
  49 #define FREQ_MUL 16000U
  50
  51 /* USB Device ID List */
  52 static struct usb_device_id usb_keene_device_table[] = {
  53         {USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
  54                                                         USB_CLASS_HID, 0, 0) },
  55         { }                                             /* Terminating entry */
  56 };
  57
  58 MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
  59
  60 struct keene_device {
  61         struct usb_device *usbdev;
  62         struct usb_interface *intf;
  63         struct video_device vdev;
  64         struct v4l2_device v4l2_dev;
  65         struct v4l2_ctrl_handler hdl;
  66         struct mutex lock;
  67
  68         u8 *buffer;
  69         unsigned curfreq;
  70         u8 tx;
  71         u8 pa;
  72         bool stereo;
  73         bool muted;
  74         bool preemph_75_us;
  75 };
  76
  77 static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
  78 {
  79         return container_of(v4l2_dev, struct keene_device, v4l2_dev);
  80 }
  81
  82 /* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
  83 static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
  84 {
  85         unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
  86         int ret;
  87
  88         radio->buffer[0] = 0x00;
  89         radio->buffer[1] = 0x50;
  90         radio->buffer[2] = (freq_send >> 8) & 0xff;
  91         radio->buffer[3] = freq_send & 0xff;
  92         radio->buffer[4] = radio->pa;
  93         /* If bit 4 is set, then tune to the frequency.
  94            If bit 3 is set, then unmute; if bit 2 is set, then mute.
  95            If bit 1 is set, then enter idle mode; if bit 0 is set,
  96            then enter transmit mode.
  97          */
  98         radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
  99                                                         (freq ? 0x10 : 0);
 100         radio->buffer[6] = 0x00;
 101         radio->buffer[7] = 0x00;
 102
 103         ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 104                 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
 105
 106         if (ret < 0) {
 107                 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
 108                 return ret;
 109         }
 110         if (freq)
 111                 radio->curfreq = freq;
 112         return 0;
 113 }
 114
 115 /* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
 116 static int keene_cmd_set(struct keene_device *radio)
 117 {
 118         int ret;
 119
 120         radio->buffer[0] = 0x00;
 121         radio->buffer[1] = 0x51;
 122         radio->buffer[2] = radio->tx;
 123         /* If bit 0 is set, then transmit mono, otherwise stereo.
 124            If bit 2 is set, then enable 75 us preemphasis, otherwise
 125            it is 50 us. */
 126         radio->buffer[3] = (!radio->stereo) | (radio->preemph_75_us ? 4 : 0);
 127         radio->buffer[4] = 0x00;
 128         radio->buffer[5] = 0x00;
 129         radio->buffer[6] = 0x00;
 130         radio->buffer[7] = 0x00;
 131
 132         ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 133                 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
 134
 135         if (ret < 0) {
 136                 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
 137                 return ret;
 138         }
 139         return 0;
 140 }
 141
 142 /* Handle unplugging the device.
 143  * We call video_unregister_device in any case.
 144  * The last function called in this procedure is
 145  * usb_keene_device_release.
 146  */
 147 static void usb_keene_disconnect(struct usb_interface *intf)
 148 {
 149         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 150
 151         mutex_lock(&radio->lock);
 152         usb_set_intfdata(intf, NULL);
 153         video_unregister_device(&radio->vdev);
 154         v4l2_device_disconnect(&radio->v4l2_dev);
 155         mutex_unlock(&radio->lock);
 156         v4l2_device_put(&radio->v4l2_dev);
 157 }
 158
 159 static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
 160 {
 161         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 162
 163         return keene_cmd_main(radio, 0, false);
 164 }
 165
 166 static int usb_keene_resume(struct usb_interface *intf)
 167 {
 168         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 169
 170         mdelay(50);
 171         keene_cmd_set(radio);
 172         keene_cmd_main(radio, radio->curfreq, true);
 173         return 0;
 174 }
 175
 176 static int vidioc_querycap(struct file *file, void *priv,
 177                                         struct v4l2_capability *v)
 178 {
 179         struct keene_device *radio = video_drvdata(file);
 180
 181         strlcpy(v->driver, "radio-keene", sizeof(v->driver));
 182         strlcpy(v->card, "Keene FM Transmitter", sizeof(v->card));
 183         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 184         v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
 185         v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
 186         return 0;
 187 }
 188
 189 static int vidioc_g_modulator(struct file *file, void *priv,
 190                                 struct v4l2_modulator *v)
 191 {
 192         struct keene_device *radio = video_drvdata(file);
 193
 194         if (v->index > 0)
 195                 return -EINVAL;
 196
 197         strlcpy(v->name, "FM", sizeof(v->name));
 198         v->rangelow = FREQ_MIN * FREQ_MUL;
 199         v->rangehigh = FREQ_MAX * FREQ_MUL;
 200         v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
 201         v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
 202         return 0;
 203 }
 204
 205 static int vidioc_s_modulator(struct file *file, void *priv,
 206                                 const struct v4l2_modulator *v)
 207 {
 208         struct keene_device *radio = video_drvdata(file);
 209
 210         if (v->index > 0)
 211                 return -EINVAL;
 212
 213         radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
 214         return keene_cmd_set(radio);
 215 }
 216
 217 static int vidioc_s_frequency(struct file *file, void *priv,
 218                                 const struct v4l2_frequency *f)
 219 {
 220         struct keene_device *radio = video_drvdata(file);
 221         unsigned freq = f->frequency;
 222
 223         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 224                 return -EINVAL;
 225         freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
 226         return keene_cmd_main(radio, freq, true);
 227 }
 228
 229 static int vidioc_g_frequency(struct file *file, void *priv,
 230                                 struct v4l2_frequency *f)
 231 {
 232         struct keene_device *radio = video_drvdata(file);
 233
 234         if (f->tuner != 0)
 235                 return -EINVAL;
 236         f->type = V4L2_TUNER_RADIO;
 237         f->frequency = radio->curfreq;
 238         return 0;
 239 }
 240
 241 static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
 242 {
 243         static const u8 db2tx[] = {
 244              /*  -15,  -12,   -9,   -6,   -3,    0 dB */
 245                 0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
 246              /*    3,    6,    9,   12,   15,   18 dB */
 247                 0x21, 0x31, 0x20, 0x30, 0x40, 0x50
 248         };
 249         struct keene_device *radio =
 250                 container_of(ctrl->handler, struct keene_device, hdl);
 251
 252         switch (ctrl->id) {
 253         case V4L2_CID_AUDIO_MUTE:
 254                 radio->muted = ctrl->val;
 255                 return keene_cmd_main(radio, 0, true);
 256
 257         case V4L2_CID_TUNE_POWER_LEVEL:
 258                 /* To go from dBuV to the register value we apply the
 259                    following formula: */
 260                 radio->pa = (ctrl->val - 71) * 100 / 62;
 261                 return keene_cmd_main(radio, 0, true);
 262
 263         case V4L2_CID_TUNE_PREEMPHASIS:
 264                 radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
 265                 return keene_cmd_set(radio);
 266
 267         case V4L2_CID_AUDIO_COMPRESSION_GAIN:
 268                 radio->tx = db2tx[(ctrl->val - ctrl->minimum) / ctrl->step];
 269                 return keene_cmd_set(radio);
 270         }
 271         return -EINVAL;
 272 }
 273
 274 /* File system interface */
 275 static const struct v4l2_file_operations usb_keene_fops = {
 276         .owner          = THIS_MODULE,
 277         .open           = v4l2_fh_open,
 278         .release        = v4l2_fh_release,
 279         .poll           = v4l2_ctrl_poll,
 280         .unlocked_ioctl = video_ioctl2,
 281 };
 282
 283 static const struct v4l2_ctrl_ops keene_ctrl_ops = {
 284         .s_ctrl = keene_s_ctrl,
 285 };
 286
 287 static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
 288         .vidioc_querycap    = vidioc_querycap,
 289         .vidioc_g_modulator = vidioc_g_modulator,
 290         .vidioc_s_modulator = vidioc_s_modulator,
 291         .vidioc_g_frequency = vidioc_g_frequency,
 292         .vidioc_s_frequency = vidioc_s_frequency,
 293         .vidioc_log_status = v4l2_ctrl_log_status,
 294         .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 295         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 296 };
 297
 298 static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
 299 {
 300         struct keene_device *radio = to_keene_dev(v4l2_dev);
 301
 302         /* free rest memory */
 303         v4l2_ctrl_handler_free(&radio->hdl);
 304         kfree(radio->buffer);
 305         kfree(radio);
 306 }
 307
 308 /* check if the device is present and register with v4l and usb if it is */
 309 static int usb_keene_probe(struct usb_interface *intf,
 310                                 const struct usb_device_id *id)
 311 {
 312         struct usb_device *dev = interface_to_usbdev(intf);
 313         struct keene_device *radio;
 314         struct v4l2_ctrl_handler *hdl;
 315         int retval = 0;
 316
 317         /*
 318          * The Keene FM transmitter USB device has the same USB ID as
 319          * the Logitech AudioHub Speaker, but it should ignore the hid.
 320          * Check if the name is that of the Keene device.
 321          * If not, then someone connected the AudioHub and we shouldn't
 322          * attempt to handle this driver.
 323          * For reference: the product name of the AudioHub is
 324          * "AudioHub Speaker".
 325          */
 326         if (dev->product && strcmp(dev->product, "B-LINK USB Audio  "))
 327                 return -ENODEV;
 328
 329         radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
 330         if (radio)
 331                 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 332
 333         if (!radio || !radio->buffer) {
 334                 dev_err(&intf->dev, "kmalloc for keene_device failed\n");
 335                 kfree(radio);
 336                 retval = -ENOMEM;
 337                 goto err;
 338         }
 339
 340         hdl = &radio->hdl;
 341         v4l2_ctrl_handler_init(hdl, 4);
 342         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
 343                         0, 1, 1, 0);
 344         v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
 345                         V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
 346         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
 347                         84, 118, 1, 118);
 348         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
 349                         -15, 18, 3, 0);
 350         radio->pa = 118;
 351         radio->tx = 0x32;
 352         radio->stereo = true;
 353         if (hdl->error) {
 354                 retval = hdl->error;
 355
 356                 v4l2_ctrl_handler_free(hdl);
 357                 goto err_v4l2;
 358         }
 359         retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 360         if (retval < 0) {
 361                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 362                 goto err_v4l2;
 363         }
 364
 365         mutex_init(&radio->lock);
 366
 367         radio->v4l2_dev.ctrl_handler = hdl;
 368         radio->v4l2_dev.release = usb_keene_video_device_release;
 369         strlcpy(radio->vdev.name, radio->v4l2_dev.name,
 370                 sizeof(radio->vdev.name));
 371         radio->vdev.v4l2_dev = &radio->v4l2_dev;
 372         radio->vdev.fops = &usb_keene_fops;
 373         radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
 374         radio->vdev.lock = &radio->lock;
 375         radio->vdev.release = video_device_release_empty;
 376         radio->vdev.vfl_dir = VFL_DIR_TX;
 377
 378         radio->usbdev = interface_to_usbdev(intf);
 379         radio->intf = intf;
 380         usb_set_intfdata(intf, &radio->v4l2_dev);
 381
 382         video_set_drvdata(&radio->vdev, radio);
 383         set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
 384
 385         /* at least 11ms is needed in order to settle hardware */
 386         msleep(20);
 387         keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
 388
 389         retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
 390         if (retval < 0) {
 391                 dev_err(&intf->dev, "could not register video device\n");
 392                 goto err_vdev;
 393         }
 394         v4l2_ctrl_handler_setup(hdl);
 395         dev_info(&intf->dev, "V4L2 device registered as %s\n",
 396                         video_device_node_name(&radio->vdev));
 397         return 0;
 398
 399 err_vdev:
 400         v4l2_device_unregister(&radio->v4l2_dev);
 401 err_v4l2:
 402         kfree(radio->buffer);
 403         kfree(radio);
 404 err:
 405         return retval;
 406 }
 407
 408 /* USB subsystem interface */
 409 static struct usb_driver usb_keene_driver = {
 410         .name                   = "radio-keene",
 411         .probe                  = usb_keene_probe,
 412         .disconnect             = usb_keene_disconnect,
 413         .id_table               = usb_keene_device_table,
 414         .suspend                = usb_keene_suspend,
 415         .resume                 = usb_keene_resume,
 416         .reset_resume           = usb_keene_resume,
 417 };
 418
 419 static int __init keene_init(void)
 420 {
 421         int retval = usb_register(&usb_keene_driver);
 422
 423         if (retval)
 424                 pr_err(KBUILD_MODNAME
 425                         ": usb_register failed. Error number %d\n", retval);
 426
 427         return retval;
 428 }
 429
 430 static void __exit keene_exit(void)
 431 {
 432         usb_deregister(&usb_keene_driver);
 433 }
 434
 435 module_init(keene_init);
 436 module_exit(keene_exit);
 437