https://github.com/torvalds/linux
Tip revision: ce9ecca0238b140b88f43859b211c9fdfd8e5b70 authored by Linus Torvalds on 17 September 2023, 21:40:24 UTC
Linux 6.6-rc2
Linux 6.6-rc2
Tip revision: ce9ecca
radio-ma901.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for the MasterKit MA901 USB FM radio. This device plugs
* into the USB port and an analog audio input or headphones, so this thing
* only deals with initialization, frequency setting, volume.
*
* Copyright (c) 2012 Alexey Klimov <klimov.linux@gmail.com>
*/
#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>
#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
#define DRIVER_DESC "Masterkit MA901 USB FM radio driver"
#define DRIVER_VERSION "0.0.1"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);
#define USB_MA901_VENDOR 0x16c0
#define USB_MA901_PRODUCT 0x05df
/* dev_warn macro with driver name */
#define MA901_DRIVER_NAME "radio-ma901"
#define ma901radio_dev_warn(dev, fmt, arg...) \
dev_warn(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
#define ma901radio_dev_err(dev, fmt, arg...) \
dev_err(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
/* Probably USB_TIMEOUT should be modified in module parameter */
#define BUFFER_LENGTH 8
#define USB_TIMEOUT 500
#define FREQ_MIN 87.5
#define FREQ_MAX 108.0
#define FREQ_MUL 16000
#define MA901_VOLUME_MAX 16
#define MA901_VOLUME_MIN 0
/* Commands that device should understand
* List isn't full and will be updated with implementation of new functions
*/
#define MA901_RADIO_SET_FREQ 0x03
#define MA901_RADIO_SET_VOLUME 0x04
#define MA901_RADIO_SET_MONO_STEREO 0x05
/* Comfortable defines for ma901radio_set_stereo */
#define MA901_WANT_STEREO 0x50
#define MA901_WANT_MONO 0xd0
/* module parameter */
static int radio_nr = -1;
module_param(radio_nr, int, 0);
MODULE_PARM_DESC(radio_nr, "Radio file number");
/* Data for one (physical) device */
struct ma901radio_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;
u16 volume;
int stereo;
bool muted;
};
static inline struct ma901radio_device *to_ma901radio_dev(struct v4l2_device *v4l2_dev)
{
return container_of(v4l2_dev, struct ma901radio_device, v4l2_dev);
}
/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
static int ma901radio_set_freq(struct ma901radio_device *radio, int freq)
{
unsigned int freq_send = 0x300 + (freq >> 5) / 25;
int retval;
radio->buffer[0] = 0x0a;
radio->buffer[1] = MA901_RADIO_SET_FREQ;
radio->buffer[2] = ((freq_send >> 8) & 0xff) + 0x80;
radio->buffer[3] = freq_send & 0xff;
radio->buffer[4] = 0x00;
radio->buffer[5] = 0x00;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x00;
retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
9, 0x21, 0x0300, 0,
radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
if (retval < 0)
return retval;
radio->curfreq = freq;
return 0;
}
static int ma901radio_set_volume(struct ma901radio_device *radio, u16 vol_to_set)
{
int retval;
radio->buffer[0] = 0x0a;
radio->buffer[1] = MA901_RADIO_SET_VOLUME;
radio->buffer[2] = 0xc2;
radio->buffer[3] = vol_to_set + 0x20;
radio->buffer[4] = 0x00;
radio->buffer[5] = 0x00;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x00;
retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
9, 0x21, 0x0300, 0,
radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
if (retval < 0)
return retval;
radio->volume = vol_to_set;
return retval;
}
static int ma901_set_stereo(struct ma901radio_device *radio, u8 stereo)
{
int retval;
radio->buffer[0] = 0x0a;
radio->buffer[1] = MA901_RADIO_SET_MONO_STEREO;
radio->buffer[2] = stereo;
radio->buffer[3] = 0x00;
radio->buffer[4] = 0x00;
radio->buffer[5] = 0x00;
radio->buffer[6] = 0x00;
radio->buffer[7] = 0x00;
retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
9, 0x21, 0x0300, 0,
radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
if (retval < 0)
return retval;
if (stereo == MA901_WANT_STEREO)
radio->stereo = V4L2_TUNER_MODE_STEREO;
else
radio->stereo = V4L2_TUNER_MODE_MONO;
return retval;
}
/* Handle unplugging the device.
* We call video_unregister_device in any case.
* The last function called in this procedure is
* usb_ma901radio_device_release.
*/
static void usb_ma901radio_disconnect(struct usb_interface *intf)
{
struct ma901radio_device *radio = to_ma901radio_dev(usb_get_intfdata(intf));
mutex_lock(&radio->lock);
video_unregister_device(&radio->vdev);
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 ma901radio_device *radio = video_drvdata(file);
strscpy(v->driver, "radio-ma901", sizeof(v->driver));
strscpy(v->card, "Masterkit MA901 USB FM Radio", sizeof(v->card));
usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
return 0;
}
/* vidioc_g_tuner - get tuner attributes */
static int vidioc_g_tuner(struct file *file, void *priv,
struct v4l2_tuner *v)
{
struct ma901radio_device *radio = video_drvdata(file);
if (v->index > 0)
return -EINVAL;
v->signal = 0;
/* TODO: the same words like in _probe() goes here.
* When receiving of stats will be implemented then we can call
* ma901radio_get_stat().
* retval = ma901radio_get_stat(radio, &is_stereo, &v->signal);
*/
strscpy(v->name, "FM", sizeof(v->name));
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;
/* 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,
const struct v4l2_tuner *v)
{
struct ma901radio_device *radio = video_drvdata(file);
if (v->index > 0)
return -EINVAL;
/* mono/stereo selector */
switch (v->audmode) {
case V4L2_TUNER_MODE_MONO:
return ma901_set_stereo(radio, MA901_WANT_MONO);
default:
return ma901_set_stereo(radio, MA901_WANT_STEREO);
}
}
/* vidioc_s_frequency - set tuner radio frequency */
static int vidioc_s_frequency(struct file *file, void *priv,
const struct v4l2_frequency *f)
{
struct ma901radio_device *radio = video_drvdata(file);
if (f->tuner != 0)
return -EINVAL;
return ma901radio_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 ma901radio_device *radio = video_drvdata(file);
if (f->tuner != 0)
return -EINVAL;
f->frequency = radio->curfreq;
return 0;
}
static int usb_ma901radio_s_ctrl(struct v4l2_ctrl *ctrl)
{
struct ma901radio_device *radio =
container_of(ctrl->handler, struct ma901radio_device, hdl);
switch (ctrl->id) {
case V4L2_CID_AUDIO_VOLUME: /* set volume */
return ma901radio_set_volume(radio, (u16)ctrl->val);
}
return -EINVAL;
}
/* TODO: Should we really need to implement suspend and resume functions?
* Radio has it's own memory and will continue playing if power is present
* on usb port and on resume it will start to play again based on freq, volume
* values in device memory.
*/
static int usb_ma901radio_suspend(struct usb_interface *intf, pm_message_t message)
{
return 0;
}
static int usb_ma901radio_resume(struct usb_interface *intf)
{
return 0;
}
static const struct v4l2_ctrl_ops usb_ma901radio_ctrl_ops = {
.s_ctrl = usb_ma901radio_s_ctrl,
};
/* File system interface */
static const struct v4l2_file_operations usb_ma901radio_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_ma901radio_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_log_status = v4l2_ctrl_log_status,
.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};
static void usb_ma901radio_release(struct v4l2_device *v4l2_dev)
{
struct ma901radio_device *radio = to_ma901radio_dev(v4l2_dev);
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_ma901radio_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usb_device *dev = interface_to_usbdev(intf);
struct ma901radio_device *radio;
int retval = 0;
/* Masterkit MA901 usb radio has the same USB ID as many others
* Atmel V-USB devices. Let's make additional checks to be sure
* that this is our device.
*/
if (dev->product && dev->manufacturer &&
(strncmp(dev->product, "MA901", 5) != 0
|| strncmp(dev->manufacturer, "www.masterkit.ru", 16) != 0))
return -ENODEV;
radio = kzalloc(sizeof(struct ma901radio_device), GFP_KERNEL);
if (!radio) {
dev_err(&intf->dev, "kzalloc for ma901radio_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);
/* TODO:It looks like this radio doesn't have mute/unmute control
* and windows program just emulate it using volume control.
* Let's plan to do the same in this driver.
*
* v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
* V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
*/
v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
V4L2_CID_AUDIO_VOLUME, MA901_VOLUME_MIN,
MA901_VOLUME_MAX, 1, MA901_VOLUME_MAX);
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_ma901radio_release;
strscpy(radio->vdev.name, radio->v4l2_dev.name,
sizeof(radio->vdev.name));
radio->vdev.v4l2_dev = &radio->v4l2_dev;
radio->vdev.fops = &usb_ma901radio_fops;
radio->vdev.ioctl_ops = &usb_ma901radio_ioctl_ops;
radio->vdev.release = video_device_release_empty;
radio->vdev.lock = &radio->lock;
radio->vdev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
radio->usbdev = interface_to_usbdev(intf);
radio->intf = intf;
usb_set_intfdata(intf, &radio->v4l2_dev);
radio->curfreq = 95.21 * FREQ_MUL;
video_set_drvdata(&radio->vdev, radio);
/* TODO: we can get some statistics (freq, volume) from device
* but it's not implemented yet. After insertion in usb-port radio
* setups frequency and starts playing without any initialization.
* So we don't call usb_ma901radio_init/get_stat() here.
* retval = usb_ma901radio_init(radio);
*/
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 const struct usb_device_id usb_ma901radio_device_table[] = {
{ USB_DEVICE_AND_INTERFACE_INFO(USB_MA901_VENDOR, USB_MA901_PRODUCT,
USB_CLASS_HID, 0, 0) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, usb_ma901radio_device_table);
/* USB subsystem interface */
static struct usb_driver usb_ma901radio_driver = {
.name = MA901_DRIVER_NAME,
.probe = usb_ma901radio_probe,
.disconnect = usb_ma901radio_disconnect,
.suspend = usb_ma901radio_suspend,
.resume = usb_ma901radio_resume,
.reset_resume = usb_ma901radio_resume,
.id_table = usb_ma901radio_device_table,
};
module_usb_driver(usb_ma901radio_driver);