linux-stable/drivers/media/radio/radio-mr800.c
Hans Verkuil 9c84d89bf1 [media] radio-mr800: fix locking order
Don't hold the lock before unregistering the device, since when the
device is unregistered the datastruct containing the lock may be freed
(if the refcount went to 0).

Also fixed the framework documentation that erroneously suggested the
wrong locking order as well.

Reported-by: David Ellingsworth <david@identd.dyndns.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: David Ellingsworth <david@identd.dyndns.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-10-21 01:18:15 -02:00

675 lines
18 KiB
C

/*
* 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 <klimov.linux@gmail.com>
*
* 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 <paravoid@debian.org> 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 <dougsland@gmail.com> and
* David Ellingsworth <david@identd.dyndns.org>
* 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/smp_lock.h>
#include <linux/input.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <linux/usb.h>
#include <linux/version.h> /* for KERNEL_VERSION MACRO */
#include <linux/mutex.h>
/* driver and module definitions */
#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
#define DRIVER_DESC "AverMedia MR 800 USB FM radio driver"
#define DRIVER_VERSION "0.11"
#define RADIO_VERSION KERNEL_VERSION(0, 1, 1)
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
#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 isnt full and will be updated with implementation of new functions
*/
#define AMRADIO_SET_FREQ 0xa4
#define AMRADIO_SET_MUTE 0xab
#define AMRADIO_SET_MONO 0xae
/* Comfortable defines for amradio_set_mute */
#define AMRADIO_START 0x00
#define AMRADIO_STOP 0x01
/* 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");
static int usb_amradio_probe(struct usb_interface *intf,
const struct usb_device_id *id);
static void usb_amradio_disconnect(struct usb_interface *intf);
static int usb_amradio_open(struct file *file);
static int usb_amradio_close(struct file *file);
static int usb_amradio_suspend(struct usb_interface *intf,
pm_message_t message);
static int usb_amradio_resume(struct usb_interface *intf);
/* 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 videodev;
struct v4l2_device v4l2_dev;
unsigned char *buffer;
struct mutex lock; /* buffer locking */
int curfreq;
int stereo;
int muted;
int initialized;
};
static inline struct amradio_device *to_amradio_dev(struct v4l2_device *v4l2_dev)
{
return container_of(v4l2_dev, struct amradio_device, v4l2_dev);
}
/* 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,
.supports_autosuspend = 1,
};
/* switch on/off the radio. Send 8 bytes to device */
static int amradio_set_mute(struct amradio_device *radio, char argument)
{
int retval;
int size;
radio->buffer[0] = 0x00;
radio->buffer[1] = 0x55;
radio->buffer[2] = 0xaa;
radio->buffer[3] = 0x00;
radio->buffer[4] = AMRADIO_SET_MUTE;
radio->buffer[5] = argument;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x00;
retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
if (retval < 0 || size != BUFFER_LENGTH) {
amradio_dev_warn(&radio->videodev.dev, "set mute failed\n");
return retval;
}
radio->muted = argument;
return retval;
}
/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
static int amradio_setfreq(struct amradio_device *radio, int freq)
{
int retval;
int size;
unsigned short freq_send = 0x10 + (freq >> 3) / 25;
radio->buffer[0] = 0x00;
radio->buffer[1] = 0x55;
radio->buffer[2] = 0xaa;
radio->buffer[3] = 0x03;
radio->buffer[4] = AMRADIO_SET_FREQ;
radio->buffer[5] = 0x00;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x08;
retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
if (retval < 0 || size != BUFFER_LENGTH)
goto out_err;
/* frequency is calculated from freq_send and placed in first 2 bytes */
radio->buffer[0] = (freq_send >> 8) & 0xff;
radio->buffer[1] = freq_send & 0xff;
radio->buffer[2] = 0x01;
radio->buffer[3] = 0x00;
radio->buffer[4] = 0x00;
/* 5 and 6 bytes of buffer already = 0x00 */
radio->buffer[7] = 0x00;
retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
if (retval < 0 || size != BUFFER_LENGTH)
goto out_err;
radio->curfreq = freq;
goto out;
out_err:
amradio_dev_warn(&radio->videodev.dev, "set frequency failed\n");
out:
return retval;
}
static int amradio_set_stereo(struct amradio_device *radio, char argument)
{
int retval;
int size;
radio->buffer[0] = 0x00;
radio->buffer[1] = 0x55;
radio->buffer[2] = 0xaa;
radio->buffer[3] = 0x00;
radio->buffer[4] = AMRADIO_SET_MONO;
radio->buffer[5] = argument;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x00;
retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
if (retval < 0 || size != BUFFER_LENGTH) {
amradio_dev_warn(&radio->videodev.dev, "set stereo failed\n");
return retval;
}
if (argument == WANT_STEREO)
radio->stereo = 1;
else
radio->stereo = 0;
return retval;
}
/* 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);
v4l2_device_disconnect(&radio->v4l2_dev);
mutex_unlock(&radio->lock);
video_unregister_device(&radio->videodev);
}
/* vidioc_querycap - query device capabilities */
static int vidioc_querycap(struct file *file, void *priv,
struct v4l2_capability *v)
{
struct amradio_device *radio = file->private_data;
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->version = RADIO_VERSION;
v->capabilities = V4L2_CAP_TUNER;
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 = file->private_data;
int retval;
if (v->index > 0)
return -EINVAL;
/* TODO: Add function which look is signal stereo or not
* amradio_getstat(radio);
*/
/* we call amradio_set_stereo to set radio->stereo
* Honestly, amradio_getstat should cover this in future and
* amradio_set_stereo shouldn't be here
*/
retval = amradio_set_stereo(radio, WANT_STEREO);
strcpy(v->name, "FM");
v->type = V4L2_TUNER_RADIO;
v->rangelow = FREQ_MIN * FREQ_MUL;
v->rangehigh = FREQ_MAX * FREQ_MUL;
v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
v->capability = V4L2_TUNER_CAP_LOW;
if (radio->stereo)
v->audmode = V4L2_TUNER_MODE_STEREO;
else
v->audmode = V4L2_TUNER_MODE_MONO;
v->signal = 0xffff; /* Can't get the signal strength, sad.. */
v->afc = 0; /* Don't know what is this */
return retval;
}
/* vidioc_s_tuner - set tuner attributes */
static int vidioc_s_tuner(struct file *file, void *priv,
struct v4l2_tuner *v)
{
struct amradio_device *radio = file->private_data;
int retval = -EINVAL;
if (v->index > 0)
return -EINVAL;
/* mono/stereo selector */
switch (v->audmode) {
case V4L2_TUNER_MODE_MONO:
retval = amradio_set_stereo(radio, WANT_MONO);
break;
case V4L2_TUNER_MODE_STEREO:
retval = amradio_set_stereo(radio, WANT_STEREO);
break;
}
return retval;
}
/* 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 = file->private_data;
if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
return -EINVAL;
return amradio_setfreq(radio, f->frequency);
}
/* 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 = file->private_data;
if (f->tuner != 0)
return -EINVAL;
f->type = V4L2_TUNER_RADIO;
f->frequency = radio->curfreq;
return 0;
}
/* vidioc_queryctrl - enumerate control items */
static int vidioc_queryctrl(struct file *file, void *priv,
struct v4l2_queryctrl *qc)
{
switch (qc->id) {
case V4L2_CID_AUDIO_MUTE:
return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
}
return -EINVAL;
}
/* vidioc_g_ctrl - get the value of a control */
static int vidioc_g_ctrl(struct file *file, void *priv,
struct v4l2_control *ctrl)
{
struct amradio_device *radio = file->private_data;
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
ctrl->value = radio->muted;
return 0;
}
return -EINVAL;
}
/* vidioc_s_ctrl - set the value of a control */
static int vidioc_s_ctrl(struct file *file, void *priv,
struct v4l2_control *ctrl)
{
struct amradio_device *radio = file->private_data;
int retval = -EINVAL;
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
if (ctrl->value)
retval = amradio_set_mute(radio, AMRADIO_STOP);
else
retval = amradio_set_mute(radio, AMRADIO_START);
break;
}
return retval;
}
/* vidioc_g_audio - get audio attributes */
static int vidioc_g_audio(struct file *file, void *priv,
struct v4l2_audio *a)
{
if (a->index > 1)
return -EINVAL;
strcpy(a->name, "Radio");
a->capability = V4L2_AUDCAP_STEREO;
return 0;
}
/* vidioc_s_audio - set audio attributes */
static int vidioc_s_audio(struct file *file, void *priv,
struct v4l2_audio *a)
{
if (a->index != 0)
return -EINVAL;
return 0;
}
/* vidioc_g_input - get input */
static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
{
*i = 0;
return 0;
}
/* vidioc_s_input - set input */
static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
{
if (i != 0)
return -EINVAL;
return 0;
}
static int usb_amradio_init(struct amradio_device *radio)
{
int retval;
retval = amradio_set_mute(radio, AMRADIO_STOP);
if (retval)
goto out_err;
retval = amradio_set_stereo(radio, WANT_STEREO);
if (retval)
goto out_err;
radio->initialized = 1;
goto out;
out_err:
amradio_dev_err(&radio->videodev.dev, "initialization failed\n");
out:
return retval;
}
/* open device - amradio_start() and amradio_setfreq() */
static int usb_amradio_open(struct file *file)
{
struct amradio_device *radio = video_drvdata(file);
int retval;
file->private_data = radio;
retval = usb_autopm_get_interface(radio->intf);
if (retval)
return retval;
if (unlikely(!radio->initialized)) {
retval = usb_amradio_init(radio);
if (retval)
usb_autopm_put_interface(radio->intf);
}
return retval;
}
/*close device */
static int usb_amradio_close(struct file *file)
{
struct amradio_device *radio = file->private_data;
usb_autopm_put_interface(radio->intf);
return 0;
}
/* 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));
if (!radio->muted && radio->initialized) {
amradio_set_mute(radio, AMRADIO_STOP);
radio->muted = 0;
}
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));
if (unlikely(!radio->initialized))
return 0;
if (radio->stereo)
amradio_set_stereo(radio, WANT_STEREO);
else
amradio_set_stereo(radio, WANT_MONO);
amradio_setfreq(radio, radio->curfreq);
if (!radio->muted)
amradio_set_mute(radio, AMRADIO_START);
dev_info(&intf->dev, "coming out of suspend..\n");
return 0;
}
/* File system interface */
static const struct v4l2_file_operations usb_amradio_fops = {
.owner = THIS_MODULE,
.open = usb_amradio_open,
.release = usb_amradio_close,
.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_queryctrl = vidioc_queryctrl,
.vidioc_g_ctrl = vidioc_g_ctrl,
.vidioc_s_ctrl = vidioc_s_ctrl,
.vidioc_g_audio = vidioc_g_audio,
.vidioc_s_audio = vidioc_s_audio,
.vidioc_g_input = vidioc_g_input,
.vidioc_s_input = vidioc_s_input,
};
static void usb_amradio_video_device_release(struct video_device *videodev)
{
struct amradio_device *radio = video_get_drvdata(videodev);
/* free rest memory */
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;
}
mutex_init(&radio->lock);
strlcpy(radio->videodev.name, radio->v4l2_dev.name,
sizeof(radio->videodev.name));
radio->videodev.v4l2_dev = &radio->v4l2_dev;
radio->videodev.fops = &usb_amradio_fops;
radio->videodev.ioctl_ops = &usb_amradio_ioctl_ops;
radio->videodev.release = usb_amradio_video_device_release;
radio->videodev.lock = &radio->lock;
radio->usbdev = interface_to_usbdev(intf);
radio->intf = intf;
radio->curfreq = 95.16 * FREQ_MUL;
video_set_drvdata(&radio->videodev, radio);
retval = video_register_device(&radio->videodev, 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_device_unregister(&radio->v4l2_dev);
err_v4l2:
kfree(radio->buffer);
err_nobuf:
kfree(radio);
err:
return retval;
}
static int __init amradio_init(void)
{
int retval = usb_register(&usb_amradio_driver);
pr_info(KBUILD_MODNAME
": version " DRIVER_VERSION " " DRIVER_DESC "\n");
if (retval)
pr_err(KBUILD_MODNAME
": usb_register failed. Error number %d\n", retval);
return retval;
}
static void __exit amradio_exit(void)
{
usb_deregister(&usb_amradio_driver);
}
module_init(amradio_init);
module_exit(amradio_exit);