linux/drivers/media/radio/radio-keene.c
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   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 */
  34MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
  35MODULE_DESCRIPTION("Keene FM Transmitter driver");
  36MODULE_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 */
  52static 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
  58MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
  59
  60struct 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
  77static 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. */
  83static 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). */
 116static 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 ? 0 : 1) | (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 */
 147static 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
 159static 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
 166static 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
 176static 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
 189static 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
 205static 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
 217static 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
 229static 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
 241static 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 - (s32)ctrl->minimum) / (s32)ctrl->step];
 269                return keene_cmd_set(radio);
 270        }
 271        return -EINVAL;
 272}
 273
 274/* File system interface */
 275static 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
 283static const struct v4l2_ctrl_ops keene_ctrl_ops = {
 284        .s_ctrl = keene_s_ctrl,
 285};
 286
 287static 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
 298static 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 */
 309static 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
 384        /* at least 11ms is needed in order to settle hardware */
 385        msleep(20);
 386        keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
 387
 388        retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
 389        if (retval < 0) {
 390                dev_err(&intf->dev, "could not register video device\n");
 391                goto err_vdev;
 392        }
 393        v4l2_ctrl_handler_setup(hdl);
 394        dev_info(&intf->dev, "V4L2 device registered as %s\n",
 395                        video_device_node_name(&radio->vdev));
 396        return 0;
 397
 398err_vdev:
 399        v4l2_device_unregister(&radio->v4l2_dev);
 400err_v4l2:
 401        kfree(radio->buffer);
 402        kfree(radio);
 403err:
 404        return retval;
 405}
 406
 407/* USB subsystem interface */
 408static struct usb_driver usb_keene_driver = {
 409        .name                   = "radio-keene",
 410        .probe                  = usb_keene_probe,
 411        .disconnect             = usb_keene_disconnect,
 412        .id_table               = usb_keene_device_table,
 413        .suspend                = usb_keene_suspend,
 414        .resume                 = usb_keene_resume,
 415        .reset_resume           = usb_keene_resume,
 416};
 417
 418module_usb_driver(usb_keene_driver);
 419
 420