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
  15 /* kernel includes */
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/input.h>
  21 #include <linux/videodev2.h>
  22 #include <media/v4l2-device.h>
  23 #include <media/v4l2-ioctl.h>
  24 #include <media/v4l2-ctrls.h>
  25 #include <media/v4l2-event.h>
  26 #include <linux/usb.h>
  27 #include <linux/mutex.h>
  28
  29 /* driver and module definitions */
  30 MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
  31 MODULE_DESCRIPTION("Keene FM Transmitter driver");
  32 MODULE_LICENSE("GPL");
  33
  34 /* Actually, it advertises itself as a Logitech */
  35 #define USB_KEENE_VENDOR 0x046d
  36 #define USB_KEENE_PRODUCT 0x0a0e
  37
  38 /* Probably USB_TIMEOUT should be modified in module parameter */
  39 #define BUFFER_LENGTH 8
  40 #define USB_TIMEOUT 500
  41
  42 /* Frequency limits in MHz */
  43 #define FREQ_MIN  76U
  44 #define FREQ_MAX 108U
  45 #define FREQ_MUL 16000U
  46
  47 /* USB Device ID List */
  48 static struct usb_device_id usb_keene_device_table[] = {
  49         {USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
  50                                                         USB_CLASS_HID, 0, 0) },
  51         { }                                             /* Terminating entry */
  52 };
  53
  54 MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
  55
  56 struct keene_device {
  57         struct usb_device *usbdev;
  58         struct usb_interface *intf;
  59         struct video_device vdev;
  60         struct v4l2_device v4l2_dev;
  61         struct v4l2_ctrl_handler hdl;
  62         struct mutex lock;
  63
  64         u8 *buffer;
  65         unsigned curfreq;
  66         u8 tx;
  67         u8 pa;
  68         bool stereo;
  69         bool muted;
  70         bool preemph_75_us;
  71 };
  72
  73 static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
  74 {
  75         return container_of(v4l2_dev, struct keene_device, v4l2_dev);
  76 }
  77
  78 /* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
  79 static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
  80 {
  81         unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
  82         int ret;
  83
  84         radio->buffer[0] = 0x00;
  85         radio->buffer[1] = 0x50;
  86         radio->buffer[2] = (freq_send >> 8) & 0xff;
  87         radio->buffer[3] = freq_send & 0xff;
  88         radio->buffer[4] = radio->pa;
  89         /* If bit 4 is set, then tune to the frequency.
  90            If bit 3 is set, then unmute; if bit 2 is set, then mute.
  91            If bit 1 is set, then enter idle mode; if bit 0 is set,
  92            then enter transmit mode.
  93          */
  94         radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
  95                                                         (freq ? 0x10 : 0);
  96         radio->buffer[6] = 0x00;
  97         radio->buffer[7] = 0x00;
  98
  99         ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 100                 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
 101
 102         if (ret < 0) {
 103                 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
 104                 return ret;
 105         }
 106         if (freq)
 107                 radio->curfreq = freq;
 108         return 0;
 109 }
 110
 111 /* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
 112 static int keene_cmd_set(struct keene_device *radio)
 113 {
 114         int ret;
 115
 116         radio->buffer[0] = 0x00;
 117         radio->buffer[1] = 0x51;
 118         radio->buffer[2] = radio->tx;
 119         /* If bit 0 is set, then transmit mono, otherwise stereo.
 120            If bit 2 is set, then enable 75 us preemphasis, otherwise
 121            it is 50 us. */
 122         radio->buffer[3] = (radio->stereo ? 0 : 1) | (radio->preemph_75_us ? 4 : 0);
 123         radio->buffer[4] = 0x00;
 124         radio->buffer[5] = 0x00;
 125         radio->buffer[6] = 0x00;
 126         radio->buffer[7] = 0x00;
 127
 128         ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
 129                 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
 130
 131         if (ret < 0) {
 132                 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
 133                 return ret;
 134         }
 135         return 0;
 136 }
 137
 138 /* Handle unplugging the device.
 139  * We call video_unregister_device in any case.
 140  * The last function called in this procedure is
 141  * usb_keene_device_release.
 142  */
 143 static void usb_keene_disconnect(struct usb_interface *intf)
 144 {
 145         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 146
 147         mutex_lock(&radio->lock);
 148         usb_set_intfdata(intf, NULL);
 149         video_unregister_device(&radio->vdev);
 150         v4l2_device_disconnect(&radio->v4l2_dev);
 151         mutex_unlock(&radio->lock);
 152         v4l2_device_put(&radio->v4l2_dev);
 153 }
 154
 155 static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
 156 {
 157         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 158
 159         return keene_cmd_main(radio, 0, false);
 160 }
 161
 162 static int usb_keene_resume(struct usb_interface *intf)
 163 {
 164         struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
 165
 166         mdelay(50);
 167         keene_cmd_set(radio);
 168         keene_cmd_main(radio, radio->curfreq, true);
 169         return 0;
 170 }
 171
 172 static int vidioc_querycap(struct file *file, void *priv,
 173                                         struct v4l2_capability *v)
 174 {
 175         struct keene_device *radio = video_drvdata(file);
 176
 177         strlcpy(v->driver, "radio-keene", sizeof(v->driver));
 178         strlcpy(v->card, "Keene FM Transmitter", sizeof(v->card));
 179         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 180         v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
 181         v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
 182         return 0;
 183 }
 184
 185 static int vidioc_g_modulator(struct file *file, void *priv,
 186                                 struct v4l2_modulator *v)
 187 {
 188         struct keene_device *radio = video_drvdata(file);
 189
 190         if (v->index > 0)
 191                 return -EINVAL;
 192
 193         strlcpy(v->name, "FM", sizeof(v->name));
 194         v->rangelow = FREQ_MIN * FREQ_MUL;
 195         v->rangehigh = FREQ_MAX * FREQ_MUL;
 196         v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
 197         v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
 198         return 0;
 199 }
 200
 201 static int vidioc_s_modulator(struct file *file, void *priv,
 202                                 const struct v4l2_modulator *v)
 203 {
 204         struct keene_device *radio = video_drvdata(file);
 205
 206         if (v->index > 0)
 207                 return -EINVAL;
 208
 209         radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
 210         return keene_cmd_set(radio);
 211 }
 212
 213 static int vidioc_s_frequency(struct file *file, void *priv,
 214                                 const struct v4l2_frequency *f)
 215 {
 216         struct keene_device *radio = video_drvdata(file);
 217         unsigned freq = f->frequency;
 218
 219         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 220                 return -EINVAL;
 221         freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
 222         return keene_cmd_main(radio, freq, true);
 223 }
 224
 225 static int vidioc_g_frequency(struct file *file, void *priv,
 226                                 struct v4l2_frequency *f)
 227 {
 228         struct keene_device *radio = video_drvdata(file);
 229
 230         if (f->tuner != 0)
 231                 return -EINVAL;
 232         f->type = V4L2_TUNER_RADIO;
 233         f->frequency = radio->curfreq;
 234         return 0;
 235 }
 236
 237 static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
 238 {
 239         static const u8 db2tx[] = {
 240              /*  -15,  -12,   -9,   -6,   -3,    0 dB */
 241                 0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
 242              /*    3,    6,    9,   12,   15,   18 dB */
 243                 0x21, 0x31, 0x20, 0x30, 0x40, 0x50
 244         };
 245         struct keene_device *radio =
 246                 container_of(ctrl->handler, struct keene_device, hdl);
 247
 248         switch (ctrl->id) {
 249         case V4L2_CID_AUDIO_MUTE:
 250                 radio->muted = ctrl->val;
 251                 return keene_cmd_main(radio, 0, true);
 252
 253         case V4L2_CID_TUNE_POWER_LEVEL:
 254                 /* To go from dBuV to the register value we apply the
 255                    following formula: */
 256                 radio->pa = (ctrl->val - 71) * 100 / 62;
 257                 return keene_cmd_main(radio, 0, true);
 258
 259         case V4L2_CID_TUNE_PREEMPHASIS:
 260                 radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
 261                 return keene_cmd_set(radio);
 262
 263         case V4L2_CID_AUDIO_COMPRESSION_GAIN:
 264                 radio->tx = db2tx[(ctrl->val - (s32)ctrl->minimum) / (s32)ctrl->step];
 265                 return keene_cmd_set(radio);
 266         }
 267         return -EINVAL;
 268 }
 269
 270 /* File system interface */
 271 static const struct v4l2_file_operations usb_keene_fops = {
 272         .owner          = THIS_MODULE,
 273         .open           = v4l2_fh_open,
 274         .release        = v4l2_fh_release,
 275         .poll           = v4l2_ctrl_poll,
 276         .unlocked_ioctl = video_ioctl2,
 277 };
 278
 279 static const struct v4l2_ctrl_ops keene_ctrl_ops = {
 280         .s_ctrl = keene_s_ctrl,
 281 };
 282
 283 static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
 284         .vidioc_querycap    = vidioc_querycap,
 285         .vidioc_g_modulator = vidioc_g_modulator,
 286         .vidioc_s_modulator = vidioc_s_modulator,
 287         .vidioc_g_frequency = vidioc_g_frequency,
 288         .vidioc_s_frequency = vidioc_s_frequency,
 289         .vidioc_log_status = v4l2_ctrl_log_status,
 290         .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 291         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 292 };
 293
 294 static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
 295 {
 296         struct keene_device *radio = to_keene_dev(v4l2_dev);
 297
 298         /* free rest memory */
 299         v4l2_ctrl_handler_free(&radio->hdl);
 300         kfree(radio->buffer);
 301         kfree(radio);
 302 }
 303
 304 /* check if the device is present and register with v4l and usb if it is */
 305 static int usb_keene_probe(struct usb_interface *intf,
 306                                 const struct usb_device_id *id)
 307 {
 308         struct usb_device *dev = interface_to_usbdev(intf);
 309         struct keene_device *radio;
 310         struct v4l2_ctrl_handler *hdl;
 311         int retval = 0;
 312
 313         /*
 314          * The Keene FM transmitter USB device has the same USB ID as
 315          * the Logitech AudioHub Speaker, but it should ignore the hid.
 316          * Check if the name is that of the Keene device.
 317          * If not, then someone connected the AudioHub and we shouldn't
 318          * attempt to handle this driver.
 319          * For reference: the product name of the AudioHub is
 320          * "AudioHub Speaker".
 321          */
 322         if (dev->product && strcmp(dev->product, "B-LINK USB Audio  "))
 323                 return -ENODEV;
 324
 325         radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
 326         if (radio)
 327                 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 328
 329         if (!radio || !radio->buffer) {
 330                 dev_err(&intf->dev, "kmalloc for keene_device failed\n");
 331                 kfree(radio);
 332                 retval = -ENOMEM;
 333                 goto err;
 334         }
 335
 336         hdl = &radio->hdl;
 337         v4l2_ctrl_handler_init(hdl, 4);
 338         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
 339                         0, 1, 1, 0);
 340         v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
 341                         V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
 342         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
 343                         84, 118, 1, 118);
 344         v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
 345                         -15, 18, 3, 0);
 346         radio->pa = 118;
 347         radio->tx = 0x32;
 348         radio->stereo = true;
 349         if (hdl->error) {
 350                 retval = hdl->error;
 351
 352                 v4l2_ctrl_handler_free(hdl);
 353                 goto err_v4l2;
 354         }
 355         retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 356         if (retval < 0) {
 357                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 358                 goto err_v4l2;
 359         }
 360
 361         mutex_init(&radio->lock);
 362
 363         radio->v4l2_dev.ctrl_handler = hdl;
 364         radio->v4l2_dev.release = usb_keene_video_device_release;
 365         strlcpy(radio->vdev.name, radio->v4l2_dev.name,
 366                 sizeof(radio->vdev.name));
 367         radio->vdev.v4l2_dev = &radio->v4l2_dev;
 368         radio->vdev.fops = &usb_keene_fops;
 369         radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
 370         radio->vdev.lock = &radio->lock;
 371         radio->vdev.release = video_device_release_empty;
 372         radio->vdev.vfl_dir = VFL_DIR_TX;
 373
 374         radio->usbdev = interface_to_usbdev(intf);
 375         radio->intf = intf;
 376         usb_set_intfdata(intf, &radio->v4l2_dev);
 377
 378         video_set_drvdata(&radio->vdev, radio);
 379
 380         /* at least 11ms is needed in order to settle hardware */
 381         msleep(20);
 382         keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
 383
 384         retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
 385         if (retval < 0) {
 386                 dev_err(&intf->dev, "could not register video device\n");
 387                 goto err_vdev;
 388         }
 389         v4l2_ctrl_handler_setup(hdl);
 390         dev_info(&intf->dev, "V4L2 device registered as %s\n",
 391                         video_device_node_name(&radio->vdev));
 392         return 0;
 393
 394 err_vdev:
 395         v4l2_device_unregister(&radio->v4l2_dev);
 396 err_v4l2:
 397         kfree(radio->buffer);
 398         kfree(radio);
 399 err:
 400         return retval;
 401 }
 402
 403 /* USB subsystem interface */
 404 static struct usb_driver usb_keene_driver = {
 405         .name                   = "radio-keene",
 406         .probe                  = usb_keene_probe,
 407         .disconnect             = usb_keene_disconnect,
 408         .id_table               = usb_keene_device_table,
 409         .suspend                = usb_keene_suspend,
 410         .resume                 = usb_keene_resume,
 411         .reset_resume           = usb_keene_resume,
 412 };
 413
 414 module_usb_driver(usb_keene_driver);
 415