radio-mr800.c

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/*
 * A driver for the AverMedia MR 800 USB FM radio. This device plugs
 * into both the USB and an analog audio input, so this thing
 * only deals with initialization and frequency setting, the
 * audio data has to be handled by a sound driver.
 *
 * Copyright (c) 2008 Alexey Klimov <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
 * Big thanks to authors and contributors of dsbr100.c and radio-si470x.c
 *
 * When work was looked pretty good, i discover this:
 * http://av-usbradio.sourceforge.net/index.php
 * http://sourceforge.net/projects/av-usbradio/
 * Latest release of theirs project was in 2005.
 * Probably, this driver could be improved through using their
 * achievements (specifications given).
 * Also, Faidon Liambotis <[email protected]> wrote nice driver for this radio
 * in 2007. He allowed to use his driver to improve current mr800 radio driver.
 * http://kerneltrap.org/mailarchive/linux-usb-devel/2007/10/11/342492
 *
 * Version 0.01:    First working version.
 *          It's required to blacklist AverMedia USB Radio
 *          in usbhid/hid-quirks.c
 * Version 0.10:    A lot of cleanups and fixes: unpluging the device,
 *          few mutex locks were added, codinstyle issues, etc.
 *          Added stereo support. Thanks to
 *          Douglas Schilling Landgraf <[email protected]> and
 *          David Ellingsworth <[email protected]>
 *          for discussion, help and support.
 * Version 0.11:    Converted to v4l2_device.
 *
 * Many things to do:
 *  - Correct power management of device (suspend & resume)
 *  - Add code for scanning and smooth tuning
 *  - Add code for sensitivity value
 *  - Correct mistakes
 *  - In Japan another FREQ_MIN and FREQ_MAX
 */

/* kernel includes */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <linux/usb.h>
#include <linux/mutex.h>

/* driver and module definitions */
#define DRIVER_AUTHOR "Alexey Klimov <[email protected]>"
#define DRIVER_DESC "AverMedia MR 800 USB FM radio driver"
#define DRIVER_VERSION "0.1.2"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);

#define USB_AMRADIO_VENDOR 0x07ca
#define USB_AMRADIO_PRODUCT 0xb800

/* dev_warn macro with driver name */
#define MR800_DRIVER_NAME "radio-mr800"
#define amradio_dev_warn(dev, fmt, arg...)              \
        dev_warn(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

#define amradio_dev_err(dev, fmt, arg...) \
        dev_err(dev, MR800_DRIVER_NAME " - " fmt, ##arg)

/* Probably USB_TIMEOUT should be modified in module parameter */
#define BUFFER_LENGTH 8
#define USB_TIMEOUT 500

/* Frequency limits in MHz -- these are European values.  For Japanese
devices, that would be 76 and 91.  */
#define FREQ_MIN  87.5
#define FREQ_MAX 108.0
#define FREQ_MUL 16000

/*
 * Commands that device should understand
 * List isn't full and will be updated with implementation of new functions
 */
#define AMRADIO_SET_FREQ    0xa4
#define AMRADIO_GET_READY_FLAG  0xa5
#define AMRADIO_GET_SIGNAL  0xa7
#define AMRADIO_GET_FREQ    0xa8
#define AMRADIO_SET_SEARCH_UP   0xa9
#define AMRADIO_SET_SEARCH_DOWN 0xaa
#define AMRADIO_SET_MUTE    0xab
#define AMRADIO_SET_RIGHT_MUTE  0xac
#define AMRADIO_SET_LEFT_MUTE   0xad
#define AMRADIO_SET_MONO    0xae
#define AMRADIO_SET_SEARCH_LVL  0xb0
#define AMRADIO_STOP_SEARCH 0xb1

/* Comfortable defines for amradio_set_stereo */
#define WANT_STEREO     0x00
#define WANT_MONO       0x01

/* module parameter */
static int radio_nr = -1;
module_param(radio_nr, int, 0);
MODULE_PARM_DESC(radio_nr, "Radio Nr");

/* Data for one (physical) device */
struct amradio_device {
    /* reference to USB and video device */
    struct usb_device *usbdev;
    struct usb_interface *intf;
    struct video_device vdev;
    struct v4l2_device v4l2_dev;
    struct v4l2_ctrl_handler hdl;

    u8 *buffer;
    struct mutex lock;  /* buffer locking */
    int curfreq;
    int stereo;
    int muted;
};

static inline struct amradio_device *to_amradio_dev(struct v4l2_device *v4l2_dev)
{
    return container_of(v4l2_dev, struct amradio_device, v4l2_dev);
}

static int amradio_send_cmd(struct amradio_device *radio, u8 cmd, u8 arg,
        u8 *extra, u8 extralen, bool reply)
{
    int retval;
    int size;

    radio->buffer[0] = 0x00;
    radio->buffer[1] = 0x55;
    radio->buffer[2] = 0xaa;
    radio->buffer[3] = extralen;
    radio->buffer[4] = cmd;
    radio->buffer[5] = arg;
    radio->buffer[6] = 0x00;
    radio->buffer[7] = extra || reply ? 8 : 0;

    retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
        radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);

    if (retval < 0 || size != BUFFER_LENGTH) {
        if (video_is_registered(&radio->vdev))
            amradio_dev_warn(&radio->vdev.dev,
                    "cmd %02x failed\n", cmd);
        return retval ? retval : -EIO;
    }
    if (!extra && !reply)
        return 0;

    if (extra) {
        memcpy(radio->buffer, extra, extralen);
        memset(radio->buffer + extralen, 0, 8 - extralen);
        retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
            radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
    } else {
        memset(radio->buffer, 0, 8);
        retval = usb_bulk_msg(radio->usbdev, usb_rcvbulkpipe(radio->usbdev, 0x81),
            radio->buffer, BUFFER_LENGTH, &size, USB_TIMEOUT);
    }
    if (retval == 0 && size == BUFFER_LENGTH)
        return 0;
    if (video_is_registered(&radio->vdev) && cmd != AMRADIO_GET_READY_FLAG)
        amradio_dev_warn(&radio->vdev.dev, "follow-up to cmd %02x failed\n", cmd);
    return retval ? retval : -EIO;
}

/* switch on/off the radio. Send 8 bytes to device */
static int amradio_set_mute(struct amradio_device *radio, bool mute)
{
    int ret = amradio_send_cmd(radio,
            AMRADIO_SET_MUTE, mute, NULL, 0, false);

    if (!ret)
        radio->muted = mute;
    return ret;
}

/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
static int amradio_set_freq(struct amradio_device *radio, int freq)
{
    unsigned short freq_send = 0x10 + (freq >> 3) / 25;
    u8 buf[3];
    int retval;

    /* frequency is calculated from freq_send and placed in first 2 bytes */
    buf[0] = (freq_send >> 8) & 0xff;
    buf[1] = freq_send & 0xff;
    buf[2] = 0x01;

    retval = amradio_send_cmd(radio, AMRADIO_SET_FREQ, 0, buf, 3, false);
    if (retval)
        return retval;
    radio->curfreq = freq;
    msleep(40);
    return 0;
}

static int amradio_set_stereo(struct amradio_device *radio, bool stereo)
{
    int ret = amradio_send_cmd(radio,
            AMRADIO_SET_MONO, !stereo, NULL, 0, false);

    if (!ret)
        radio->stereo = stereo;
    return ret;
}

static int amradio_get_stat(struct amradio_device *radio, bool *is_stereo, u32 *signal)
{
    int ret = amradio_send_cmd(radio,
            AMRADIO_GET_SIGNAL, 0, NULL, 0, true);

    if (ret)
        return ret;
    *is_stereo = radio->buffer[2] >> 7;
    *signal = (radio->buffer[3] & 0xf0) << 8;
    return 0;
}

/* Handle unplugging the device.
 * We call video_unregister_device in any case.
 * The last function called in this procedure is
 * usb_amradio_device_release.
 */
static void usb_amradio_disconnect(struct usb_interface *intf)
{
    struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));

    mutex_lock(&radio->lock);
    video_unregister_device(&radio->vdev);
    amradio_set_mute(radio, true);
    usb_set_intfdata(intf, NULL);
    v4l2_device_disconnect(&radio->v4l2_dev);
    mutex_unlock(&radio->lock);
    v4l2_device_put(&radio->v4l2_dev);
}

/* vidioc_querycap - query device capabilities */
static int vidioc_querycap(struct file *file, void *priv,
                    struct v4l2_capability *v)
{
    struct amradio_device *radio = video_drvdata(file);

    strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
    strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
    usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
    v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER |
                    V4L2_CAP_HW_FREQ_SEEK;
    v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
    return 0;
}

/* vidioc_g_tuner - get tuner attributes */
static int vidioc_g_tuner(struct file *file, void *priv,
                struct v4l2_tuner *v)
{
    struct amradio_device *radio = video_drvdata(file);
    bool is_stereo = false;
    int retval;

    if (v->index > 0)
        return -EINVAL;

    v->signal = 0;
    retval = amradio_get_stat(radio, &is_stereo, &v->signal);
    if (retval)
        return retval;

    strcpy(v->name, "FM");
    v->type = V4L2_TUNER_RADIO;
    v->rangelow = FREQ_MIN * FREQ_MUL;
    v->rangehigh = FREQ_MAX * FREQ_MUL;
    v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
        V4L2_TUNER_CAP_HWSEEK_WRAP;
    v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
    v->audmode = radio->stereo ?
        V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
    return 0;
}

/* vidioc_s_tuner - set tuner attributes */
static int vidioc_s_tuner(struct file *file, void *priv,
                struct v4l2_tuner *v)
{
    struct amradio_device *radio = video_drvdata(file);

    if (v->index > 0)
        return -EINVAL;

    /* mono/stereo selector */
    switch (v->audmode) {
    case V4L2_TUNER_MODE_MONO:
        return amradio_set_stereo(radio, WANT_MONO);
    default:
        return amradio_set_stereo(radio, WANT_STEREO);
    }
}

/* vidioc_s_frequency - set tuner radio frequency */
static int vidioc_s_frequency(struct file *file, void *priv,
                struct v4l2_frequency *f)
{
    struct amradio_device *radio = video_drvdata(file);

    if (f->tuner != 0)
        return -EINVAL;
    return amradio_set_freq(radio, clamp_t(unsigned, f->frequency,
                FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
}

/* vidioc_g_frequency - get tuner radio frequency */
static int vidioc_g_frequency(struct file *file, void *priv,
                struct v4l2_frequency *f)
{
    struct amradio_device *radio = video_drvdata(file);

    if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
        return -EINVAL;
    f->type = V4L2_TUNER_RADIO;
    f->frequency = radio->curfreq;

    return 0;
}

static int vidioc_s_hw_freq_seek(struct file *file, void *priv,
        const struct v4l2_hw_freq_seek *seek)
{
    static u8 buf[8] = {
        0x3d, 0x32, 0x0f, 0x08, 0x3d, 0x32, 0x0f, 0x08
    };
    struct amradio_device *radio = video_drvdata(file);
    unsigned long timeout;
    int retval;

    if (seek->tuner != 0 || !seek->wrap_around)
        return -EINVAL;

    if (file->f_flags & O_NONBLOCK)
        return -EWOULDBLOCK;

    retval = amradio_send_cmd(radio,
            AMRADIO_SET_SEARCH_LVL, 0, buf, 8, false);
    if (retval)
        return retval;
    amradio_set_freq(radio, radio->curfreq);
    retval = amradio_send_cmd(radio,
        seek->seek_upward ? AMRADIO_SET_SEARCH_UP : AMRADIO_SET_SEARCH_DOWN,
        0, NULL, 0, false);
    if (retval)
        return retval;
    timeout = jiffies + msecs_to_jiffies(30000);
    for (;;) {
        if (time_after(jiffies, timeout)) {
            retval = -ENODATA;
            break;
        }
        if (schedule_timeout_interruptible(msecs_to_jiffies(10))) {
            retval = -ERESTARTSYS;
            break;
        }
        retval = amradio_send_cmd(radio, AMRADIO_GET_READY_FLAG,
                0, NULL, 0, true);
        if (retval)
            continue;
        amradio_send_cmd(radio, AMRADIO_GET_FREQ, 0, NULL, 0, true);
        if (radio->buffer[1] || radio->buffer[2]) {
            radio->curfreq = (radio->buffer[1] << 8) | radio->buffer[2];
            radio->curfreq = (radio->curfreq - 0x10) * 200;
            amradio_send_cmd(radio, AMRADIO_STOP_SEARCH,
                    0, NULL, 0, false);
            amradio_set_freq(radio, radio->curfreq);
            retval = 0;
            break;
        }
    }
    amradio_send_cmd(radio, AMRADIO_STOP_SEARCH, 0, NULL, 0, false);
    amradio_set_freq(radio, radio->curfreq);
    return retval;
}

static int usb_amradio_s_ctrl(struct v4l2_ctrl *ctrl)
{
    struct amradio_device *radio =
        container_of(ctrl->handler, struct amradio_device, hdl);

    switch (ctrl->id) {
    case V4L2_CID_AUDIO_MUTE:
        return amradio_set_mute(radio, ctrl->val);
    }

    return -EINVAL;
}

static int usb_amradio_init(struct amradio_device *radio)
{
    int retval;

    retval = amradio_set_mute(radio, true);
    if (retval)
        goto out_err;
    retval = amradio_set_stereo(radio, true);
    if (retval)
        goto out_err;
    retval = amradio_set_freq(radio, radio->curfreq);
    if (retval)
        goto out_err;
    return 0;

out_err:
    amradio_dev_err(&radio->vdev.dev, "initialization failed\n");
    return retval;
}

/* Suspend device - stop device. Need to be checked and fixed */
static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));

    mutex_lock(&radio->lock);
    if (!radio->muted) {
        amradio_set_mute(radio, true);
        radio->muted = false;
    }
    mutex_unlock(&radio->lock);

    dev_info(&intf->dev, "going into suspend..\n");
    return 0;
}

/* Resume device - start device. Need to be checked and fixed */
static int usb_amradio_resume(struct usb_interface *intf)
{
    struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));

    mutex_lock(&radio->lock);
    amradio_set_stereo(radio, radio->stereo);
    amradio_set_freq(radio, radio->curfreq);

    if (!radio->muted)
        amradio_set_mute(radio, false);

    mutex_unlock(&radio->lock);

    dev_info(&intf->dev, "coming out of suspend..\n");
    return 0;
}

static const struct v4l2_ctrl_ops usb_amradio_ctrl_ops = {
    .s_ctrl = usb_amradio_s_ctrl,
};

/* File system interface */
static const struct v4l2_file_operations usb_amradio_fops = {
    .owner      = THIS_MODULE,
    .open       = v4l2_fh_open,
    .release    = v4l2_fh_release,
    .poll       = v4l2_ctrl_poll,
    .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
    .vidioc_querycap    = vidioc_querycap,
    .vidioc_g_tuner     = vidioc_g_tuner,
    .vidioc_s_tuner     = vidioc_s_tuner,
    .vidioc_g_frequency = vidioc_g_frequency,
    .vidioc_s_frequency = vidioc_s_frequency,
    .vidioc_s_hw_freq_seek = vidioc_s_hw_freq_seek,
    .vidioc_log_status  = v4l2_ctrl_log_status,
    .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
    .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static void usb_amradio_release(struct v4l2_device *v4l2_dev)
{
    struct amradio_device *radio = to_amradio_dev(v4l2_dev);

    /* free rest memory */
    v4l2_ctrl_handler_free(&radio->hdl);
    v4l2_device_unregister(&radio->v4l2_dev);
    kfree(radio->buffer);
    kfree(radio);
}

/* check if the device is present and register with v4l and usb if it is */
static int usb_amradio_probe(struct usb_interface *intf,
                const struct usb_device_id *id)
{
    struct amradio_device *radio;
    int retval = 0;

    radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);

    if (!radio) {
        dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
        retval = -ENOMEM;
        goto err;
    }

    radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);

    if (!radio->buffer) {
        dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
        retval = -ENOMEM;
        goto err_nobuf;
    }

    retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
    if (retval < 0) {
        dev_err(&intf->dev, "couldn't register v4l2_device\n");
        goto err_v4l2;
    }

    v4l2_ctrl_handler_init(&radio->hdl, 1);
    v4l2_ctrl_new_std(&radio->hdl, &usb_amradio_ctrl_ops,
              V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
    if (radio->hdl.error) {
        retval = radio->hdl.error;
        dev_err(&intf->dev, "couldn't register control\n");
        goto err_ctrl;
    }
    mutex_init(&radio->lock);

    radio->v4l2_dev.ctrl_handler = &radio->hdl;
    radio->v4l2_dev.release = usb_amradio_release;
    strlcpy(radio->vdev.name, radio->v4l2_dev.name,
        sizeof(radio->vdev.name));
    radio->vdev.v4l2_dev = &radio->v4l2_dev;
    radio->vdev.fops = &usb_amradio_fops;
    radio->vdev.ioctl_ops = &usb_amradio_ioctl_ops;
    radio->vdev.release = video_device_release_empty;
    radio->vdev.lock = &radio->lock;
    set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);

    radio->usbdev = interface_to_usbdev(intf);
    radio->intf = intf;
    usb_set_intfdata(intf, &radio->v4l2_dev);
    radio->curfreq = 95.16 * FREQ_MUL;

    video_set_drvdata(&radio->vdev, radio);
    retval = usb_amradio_init(radio);
    if (retval)
        goto err_vdev;

    retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
                    radio_nr);
    if (retval < 0) {
        dev_err(&intf->dev, "could not register video device\n");
        goto err_vdev;
    }

    return 0;

err_vdev:
    v4l2_ctrl_handler_free(&radio->hdl);
err_ctrl:
    v4l2_device_unregister(&radio->v4l2_dev);
err_v4l2:
    kfree(radio->buffer);
err_nobuf:
    kfree(radio);
err:
    return retval;
}

/* USB Device ID List */
static struct usb_device_id usb_amradio_device_table[] = {
    { USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
                            USB_CLASS_HID, 0, 0) },
    { }                     /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);

/* USB subsystem interface */
static struct usb_driver usb_amradio_driver = {
    .name           = MR800_DRIVER_NAME,
    .probe          = usb_amradio_probe,
    .disconnect     = usb_amradio_disconnect,
    .suspend        = usb_amradio_suspend,
    .resume         = usb_amradio_resume,
    .reset_resume       = usb_amradio_resume,
    .id_table       = usb_amradio_device_table,
};

module_usb_driver(usb_amradio_driver);