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[ALSA] usb-audio - add mixer control notifications 

USB generic driver
Add support for the optional status interrupt endpoint in audio control
interfaces, and translate USB status notifications into ALSA mixer
control notifications.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
hifive-unleashed-5.1
Clemens Ladisch 2005-04-29 16:26:14 +02:00 committed by Jaroslav Kysela
parent 84957a8ab0
commit 6639b6c236
1 changed files with 98 additions and 3 deletions
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101
sound/usb/usbmixer.c
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@ -55,6 +55,8 @@ struct usb_mixer_interface {
unsigned int ctrlif;
struct list_head list;
unsigned int ignore_ctl_error;
struct urb *urb;
usb_mixer_elem_info_t **id_elems; /* array[256], indexed by unit id */
};
@ -83,13 +85,15 @@ struct usb_mixer_build {
struct usb_mixer_elem_info {
struct usb_mixer_interface *mixer;
usb_mixer_elem_info_t *next_id_elem; /* list of controls with same id */
snd_ctl_elem_id_t *elem_id;
unsigned int id;
unsigned int control; /* CS or ICN (high byte) */
unsigned int cmask; /* channel mask bitmap: 0 = master */
int channels;
int val_type;
int min, max, res;
unsigned int initialized: 1;
u8 initialized;
};
@ -414,6 +418,7 @@ static int check_matrix_bitmap(unsigned char *bmap, int ich, int och, int num_ou
static int add_control_to_empty(mixer_build_t *state, snd_kcontrol_t *kctl)
{
usb_mixer_elem_info_t *cval = kctl->private_data;
int err;
while (snd_ctl_find_id(state->chip->card, &kctl->id))
@ -421,8 +426,12 @@ static int add_control_to_empty(mixer_build_t *state, snd_kcontrol_t *kctl)
if ((err = snd_ctl_add(state->chip->card, kctl)) < 0) {
snd_printd(KERN_ERR "cannot add control (err = %d)\n", err);
snd_ctl_free_one(kctl);
return err;
}
return err;
cval->elem_id = &kctl->id;
cval->next_id_elem = state->mixer->id_elems[cval->id];
state->mixer->id_elems[cval->id] = cval;
return 0;
}
@ -1522,6 +1531,11 @@ static int parse_audio_unit(mixer_build_t *state, int unitid)
static void snd_usb_mixer_free(struct usb_mixer_interface *mixer)
{
kfree(mixer->id_elems);
if (mixer->urb) {
kfree(mixer->urb->transfer_buffer);
usb_free_urb(mixer->urb);
}
kfree(mixer);
}
@ -1580,6 +1594,76 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
return 0;
}
static void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer,
int unitid)
{
usb_mixer_elem_info_t *info;
for (info = mixer->id_elems[unitid]; info; info = info->next_id_elem)
snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
info->elem_id);
}
static void snd_usb_mixer_status_complete(struct urb *urb, struct pt_regs *regs)
{
struct usb_mixer_interface *mixer = urb->context;
if (urb->status == 0) {
u8 *buf = urb->transfer_buffer;
int i;
for (i = urb->actual_length; i >= 2; buf += 2, i -= 2) {
snd_printd(KERN_DEBUG "status interrupt: %02x %02x\n",
buf[0], buf[1]);
/* ignore any notifications not from the control interface */
if ((buf[0] & 0x0f) != 0)
continue;
if (!(buf[0] & 0x40))
snd_usb_mixer_notify_id(mixer, buf[1]);
}
}
if (urb->status != -ENOENT && urb->status != -ECONNRESET) {
urb->dev = mixer->chip->dev;
usb_submit_urb(urb, GFP_ATOMIC);
}
}
/* create the handler for the optional status interrupt endpoint */
static int snd_usb_mixer_status_create(struct usb_mixer_interface *mixer)
{
struct usb_host_interface *hostif;
struct usb_endpoint_descriptor *ep;
void *transfer_buffer;
int buffer_length;
unsigned int epnum;
hostif = &usb_ifnum_to_if(mixer->chip->dev, mixer->ctrlif)->altsetting[0];
/* we need one interrupt input endpoint */
if (get_iface_desc(hostif)->bNumEndpoints < 1)
return 0;
ep = get_endpoint(hostif, 0);
if ((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != USB_DIR_IN ||
(ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT)
return 0;
epnum = ep->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
buffer_length = le16_to_cpu(ep->wMaxPacketSize);
transfer_buffer = kmalloc(buffer_length, GFP_KERNEL);
if (!transfer_buffer)
return -ENOMEM;
mixer->urb = usb_alloc_urb(0, GFP_KERNEL);
if (!mixer->urb) {
kfree(transfer_buffer);
return -ENOMEM;
}
usb_fill_int_urb(mixer->urb, mixer->chip->dev,
usb_rcvintpipe(mixer->chip->dev, epnum),
transfer_buffer, buffer_length,
snd_usb_mixer_status_complete, mixer, ep->bInterval);
usb_submit_urb(mixer->urb, GFP_KERNEL);
return 0;
}
int snd_usb_create_mixer(snd_usb_audio_t *chip, int ctrlif)
{
static snd_device_ops_t dev_ops = {
@ -1598,8 +1682,14 @@ int snd_usb_create_mixer(snd_usb_audio_t *chip, int ctrlif)
#ifdef IGNORE_CTL_ERROR
mixer->ignore_ctl_error = 1;
#endif
mixer->id_elems = kcalloc(256, sizeof(*mixer->id_elems), GFP_KERNEL);
if (!mixer->id_elems) {
kfree(mixer);
return -ENOMEM;
}
if ((err = snd_usb_mixer_controls(mixer)) < 0) {
if ((err = snd_usb_mixer_controls(mixer)) < 0 ||
(err = snd_usb_mixer_status_create(mixer)) < 0) {
snd_usb_mixer_free(mixer);
return err;
}
@ -1615,4 +1705,9 @@ int snd_usb_create_mixer(snd_usb_audio_t *chip, int ctrlif)
void snd_usb_mixer_disconnect(struct list_head *p)
{
struct usb_mixer_interface *mixer;
mixer = list_entry(p, struct usb_mixer_interface, list);
if (mixer->urb)
usb_kill_urb(mixer->urb);
}