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ALSA: virtio: add support for audio controls

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Implementation of support for audio controls in accordance with the
extension of the virtio sound device specification [1] planned for
virtio-v1.3-cs01.

The device can announce the VIRTIO_SND_F_CTLS feature. If the feature is
negotiated, then an additional field appears in the configuration space:

  struct virtio_snd_config {
    ...
    /* number of available control elements */
    __le32 controls;
  };

The driver can send the following requests to manage audio controls:

  enum {
    ...
    /* control element request types */
    VIRTIO_SND_R_CTL_INFO = 0x0300,
    VIRTIO_SND_R_CTL_ENUM_ITEMS,
    VIRTIO_SND_R_CTL_READ,
    VIRTIO_SND_R_CTL_WRITE,
    VIRTIO_SND_R_CTL_TLV_READ,
    VIRTIO_SND_R_CTL_TLV_WRITE,
    VIRTIO_SND_R_CTL_TLV_COMMAND,
    ...
  };

And the device can send the following audio control event notification:

  enum {
    ...
    /* control element event types */
    VIRTIO_SND_EVT_CTL_NOTIFY = 0x1200,
    ...
  };

See additional details in [1].

[1] https://lists.oasis-open.org/archives/virtio-comment/202104/msg00013.html

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
Link: https://lore.kernel.org/r/20240115133654.576068-2-aiswarya.cyriac@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Anton Yakovlev 2024-01-15 14:36:54 +01:00 committed by Takashi Iwai
parent a097812310
commit d6568e3de4
5 changed files with 664 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

154
include/uapi/linux/virtio_snd.h
View File

@ -7,6 +7,14 @@
#include <linux/virtio_types.h>
/*******************************************************************************
* FEATURE BITS
*/
enum {
/* device supports control elements */
VIRTIO_SND_F_CTLS = 0
};
/*******************************************************************************
* CONFIGURATION SPACE
*/
@ -17,6 +25,8 @@ struct virtio_snd_config {
__le32 streams;
/* # of available channel maps */
__le32 chmaps;
/* # of available control elements */
__le32 controls;
};
enum {
@ -55,6 +65,15 @@ enum {
/* channel map control request types */
VIRTIO_SND_R_CHMAP_INFO = 0x0200,
/* control element request types */
VIRTIO_SND_R_CTL_INFO = 0x0300,
VIRTIO_SND_R_CTL_ENUM_ITEMS,
VIRTIO_SND_R_CTL_READ,
VIRTIO_SND_R_CTL_WRITE,
VIRTIO_SND_R_CTL_TLV_READ,
VIRTIO_SND_R_CTL_TLV_WRITE,
VIRTIO_SND_R_CTL_TLV_COMMAND,
/* jack event types */
VIRTIO_SND_EVT_JACK_CONNECTED = 0x1000,
VIRTIO_SND_EVT_JACK_DISCONNECTED,
@ -63,6 +82,9 @@ enum {
VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED = 0x1100,
VIRTIO_SND_EVT_PCM_XRUN,
/* control element event types */
VIRTIO_SND_EVT_CTL_NOTIFY = 0x1200,
/* common status codes */
VIRTIO_SND_S_OK = 0x8000,
VIRTIO_SND_S_BAD_MSG,
@ -331,4 +353,136 @@ struct virtio_snd_chmap_info {
__u8 positions[VIRTIO_SND_CHMAP_MAX_SIZE];
};
/*******************************************************************************
* CONTROL ELEMENTS MESSAGES
*/
struct virtio_snd_ctl_hdr {
/* VIRTIO_SND_R_CTL_XXX */
struct virtio_snd_hdr hdr;
/* 0 ... virtio_snd_config::controls - 1 */
__le32 control_id;
};
/* supported roles for control elements */
enum {
VIRTIO_SND_CTL_ROLE_UNDEFINED = 0,
VIRTIO_SND_CTL_ROLE_VOLUME,
VIRTIO_SND_CTL_ROLE_MUTE,
VIRTIO_SND_CTL_ROLE_GAIN
};
/* supported value types for control elements */
enum {
VIRTIO_SND_CTL_TYPE_BOOLEAN = 0,
VIRTIO_SND_CTL_TYPE_INTEGER,
VIRTIO_SND_CTL_TYPE_INTEGER64,
VIRTIO_SND_CTL_TYPE_ENUMERATED,
VIRTIO_SND_CTL_TYPE_BYTES,
VIRTIO_SND_CTL_TYPE_IEC958
};
/* supported access rights for control elements */
enum {
VIRTIO_SND_CTL_ACCESS_READ = 0,
VIRTIO_SND_CTL_ACCESS_WRITE,
VIRTIO_SND_CTL_ACCESS_VOLATILE,
VIRTIO_SND_CTL_ACCESS_INACTIVE,
VIRTIO_SND_CTL_ACCESS_TLV_READ,
VIRTIO_SND_CTL_ACCESS_TLV_WRITE,
VIRTIO_SND_CTL_ACCESS_TLV_COMMAND
};
struct virtio_snd_ctl_info {
/* common header */
struct virtio_snd_info hdr;
/* element role (VIRTIO_SND_CTL_ROLE_XXX) */
__le32 role;
/* element value type (VIRTIO_SND_CTL_TYPE_XXX) */
__le32 type;
/* element access right bit map (1 << VIRTIO_SND_CTL_ACCESS_XXX) */
__le32 access;
/* # of members in the element value */
__le32 count;
/* index for an element with a non-unique name */
__le32 index;
/* name identifier string for the element */
__u8 name[44];
/* additional information about the element's value */
union {
/* VIRTIO_SND_CTL_TYPE_INTEGER */
struct {
/* minimum supported value */
__le32 min;
/* maximum supported value */
__le32 max;
/* fixed step size for value (0 = variable size) */
__le32 step;
} integer;
/* VIRTIO_SND_CTL_TYPE_INTEGER64 */
struct {
/* minimum supported value */
__le64 min;
/* maximum supported value */
__le64 max;
/* fixed step size for value (0 = variable size) */
__le64 step;
} integer64;
/* VIRTIO_SND_CTL_TYPE_ENUMERATED */
struct {
/* # of options supported for value */
__le32 items;
} enumerated;
} value;
};
struct virtio_snd_ctl_enum_item {
/* option name */
__u8 item[64];
};
struct virtio_snd_ctl_iec958 {
/* AES/IEC958 channel status bits */
__u8 status[24];
/* AES/IEC958 subcode bits */
__u8 subcode[147];
/* nothing */
__u8 pad;
/* AES/IEC958 subframe bits */
__u8 dig_subframe[4];
};
struct virtio_snd_ctl_value {
union {
/* VIRTIO_SND_CTL_TYPE_BOOLEAN|INTEGER value */
__le32 integer[128];
/* VIRTIO_SND_CTL_TYPE_INTEGER64 value */
__le64 integer64[64];
/* VIRTIO_SND_CTL_TYPE_ENUMERATED value (option indexes) */
__le32 enumerated[128];
/* VIRTIO_SND_CTL_TYPE_BYTES value */
__u8 bytes[512];
/* VIRTIO_SND_CTL_TYPE_IEC958 value */
struct virtio_snd_ctl_iec958 iec958;
} value;
};
/* supported event reason types */
enum {
/* element's value has changed */
VIRTIO_SND_CTL_EVT_MASK_VALUE = 0,
/* element's information has changed */
VIRTIO_SND_CTL_EVT_MASK_INFO,
/* element's metadata has changed */
VIRTIO_SND_CTL_EVT_MASK_TLV
};
struct virtio_snd_ctl_event {
/* VIRTIO_SND_EVT_CTL_NOTIFY */
struct virtio_snd_hdr hdr;
/* 0 ... virtio_snd_config::controls - 1 */
__le16 control_id;
/* event reason bit map (1 << VIRTIO_SND_CTL_EVT_MASK_XXX) */
__le16 mask;
};
#endif /* VIRTIO_SND_IF_H */

1
sound/virtio/Makefile
View File

@ -7,6 +7,7 @@ virtio_snd-objs := \
virtio_chmap.o \
virtio_ctl_msg.o \
virtio_jack.o \
virtio_kctl.o \
virtio_pcm.o \
virtio_pcm_msg.o \
virtio_pcm_ops.o

21
sound/virtio/virtio_card.c
View File

@ -64,6 +64,9 @@ static void virtsnd_event_dispatch(struct virtio_snd *snd,
case VIRTIO_SND_EVT_PCM_XRUN:
virtsnd_pcm_event(snd, event);
break;
case VIRTIO_SND_EVT_CTL_NOTIFY:
virtsnd_kctl_event(snd, event);
break;
}
}
@ -233,6 +236,12 @@ static int virtsnd_build_devs(struct virtio_snd *snd)
if (rc)
return rc;
if (virtio_has_feature(vdev, VIRTIO_SND_F_CTLS)) {
rc = virtsnd_kctl_parse_cfg(snd);
if (rc)
return rc;
}
if (snd->njacks) {
rc = virtsnd_jack_build_devs(snd);
if (rc)
@ -251,6 +260,12 @@ static int virtsnd_build_devs(struct virtio_snd *snd)
return rc;
}
if (snd->nkctls) {
rc = virtsnd_kctl_build_devs(snd);
if (rc)
return rc;
}
return snd_card_register(snd->card);
}
@ -417,10 +432,16 @@ static const struct virtio_device_id id_table[] = {
{ 0 },
};
static unsigned int features[] = {
VIRTIO_SND_F_CTLS
};
static struct virtio_driver virtsnd_driver = {
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.validate = virtsnd_validate,
.probe = virtsnd_probe,
.remove = virtsnd_remove,

22
sound/virtio/virtio_card.h
View File

@ -31,6 +31,16 @@ struct virtio_snd_queue {
struct virtqueue *vqueue;
};
/**
* struct virtio_kctl - VirtIO control element.
* @kctl: ALSA control element.
* @items: Items for the ENUMERATED element type.
*/
struct virtio_kctl {
struct snd_kcontrol *kctl;
struct virtio_snd_ctl_enum_item *items;
};
/**
* struct virtio_snd - VirtIO sound card device.
* @vdev: Underlying virtio device.
@ -45,6 +55,9 @@ struct virtio_snd_queue {
* @nsubstreams: Number of PCM substreams.
* @chmaps: VirtIO channel maps.
* @nchmaps: Number of channel maps.
* @kctl_infos: VirtIO control element information.
* @kctls: VirtIO control elements.
* @nkctls: Number of control elements.
*/
struct virtio_snd {
struct virtio_device *vdev;
@ -59,6 +72,9 @@ struct virtio_snd {
u32 nsubstreams;
struct virtio_snd_chmap_info *chmaps;
u32 nchmaps;
struct virtio_snd_ctl_info *kctl_infos;
struct virtio_kctl *kctls;
u32 nkctls;
};
/* Message completion timeout in milliseconds (module parameter). */
@ -108,4 +124,10 @@ int virtsnd_chmap_parse_cfg(struct virtio_snd *snd);
int virtsnd_chmap_build_devs(struct virtio_snd *snd);
int virtsnd_kctl_parse_cfg(struct virtio_snd *snd);
int virtsnd_kctl_build_devs(struct virtio_snd *snd);
void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event);
#endif /* VIRTIO_SND_CARD_H */

466
sound/virtio/virtio_kctl.c Normal file
View File

@ -0,0 +1,466 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* virtio-snd: Virtio sound device
* Copyright (C) 2022 OpenSynergy GmbH
*/
#include <sound/control.h>
#include <linux/virtio_config.h>
#include "virtio_card.h"
/* Map for converting VirtIO types to ALSA types. */
static const snd_ctl_elem_type_t g_v2a_type_map[] = {
[VIRTIO_SND_CTL_TYPE_BOOLEAN] = SNDRV_CTL_ELEM_TYPE_BOOLEAN,
[VIRTIO_SND_CTL_TYPE_INTEGER] = SNDRV_CTL_ELEM_TYPE_INTEGER,
[VIRTIO_SND_CTL_TYPE_INTEGER64] = SNDRV_CTL_ELEM_TYPE_INTEGER64,
[VIRTIO_SND_CTL_TYPE_ENUMERATED] = SNDRV_CTL_ELEM_TYPE_ENUMERATED,
[VIRTIO_SND_CTL_TYPE_BYTES] = SNDRV_CTL_ELEM_TYPE_BYTES,
[VIRTIO_SND_CTL_TYPE_IEC958] = SNDRV_CTL_ELEM_TYPE_IEC958
};
/* Map for converting VirtIO access rights to ALSA access rights. */
static const unsigned int g_v2a_access_map[] = {
[VIRTIO_SND_CTL_ACCESS_READ] = SNDRV_CTL_ELEM_ACCESS_READ,
[VIRTIO_SND_CTL_ACCESS_WRITE] = SNDRV_CTL_ELEM_ACCESS_WRITE,
[VIRTIO_SND_CTL_ACCESS_VOLATILE] = SNDRV_CTL_ELEM_ACCESS_VOLATILE,
[VIRTIO_SND_CTL_ACCESS_INACTIVE] = SNDRV_CTL_ELEM_ACCESS_INACTIVE,
[VIRTIO_SND_CTL_ACCESS_TLV_READ] = SNDRV_CTL_ELEM_ACCESS_TLV_READ,
[VIRTIO_SND_CTL_ACCESS_TLV_WRITE] = SNDRV_CTL_ELEM_ACCESS_TLV_WRITE,
[VIRTIO_SND_CTL_ACCESS_TLV_COMMAND] = SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND
};
/* Map for converting VirtIO event masks to ALSA event masks. */
static const unsigned int g_v2a_mask_map[] = {
[VIRTIO_SND_CTL_EVT_MASK_VALUE] = SNDRV_CTL_EVENT_MASK_VALUE,
[VIRTIO_SND_CTL_EVT_MASK_INFO] = SNDRV_CTL_EVENT_MASK_INFO,
[VIRTIO_SND_CTL_EVT_MASK_TLV] = SNDRV_CTL_EVENT_MASK_TLV
};
/**
* virtsnd_kctl_info() - Returns information about the control.
* @kcontrol: ALSA control element.
* @uinfo: Element information.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_kctl_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
struct virtio_snd *snd = kcontrol->private_data;
struct virtio_kctl *kctl = &snd->kctls[kcontrol->private_value];
struct virtio_snd_ctl_info *kinfo =
&snd->kctl_infos[kcontrol->private_value];
unsigned int i;
uinfo->type = g_v2a_type_map[le32_to_cpu(kinfo->type)];
uinfo->count = le32_to_cpu(kinfo->count);
switch (uinfo->type) {
case SNDRV_CTL_ELEM_TYPE_INTEGER:
uinfo->value.integer.min =
le32_to_cpu(kinfo->value.integer.min);
uinfo->value.integer.max =
le32_to_cpu(kinfo->value.integer.max);
uinfo->value.integer.step =
le32_to_cpu(kinfo->value.integer.step);
break;
case SNDRV_CTL_ELEM_TYPE_INTEGER64:
uinfo->value.integer64.min =
le64_to_cpu(kinfo->value.integer64.min);
uinfo->value.integer64.max =
le64_to_cpu(kinfo->value.integer64.max);
uinfo->value.integer64.step =
le64_to_cpu(kinfo->value.integer64.step);
break;
case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
uinfo->value.enumerated.items =
le32_to_cpu(kinfo->value.enumerated.items);
i = uinfo->value.enumerated.item;
if (i >= uinfo->value.enumerated.items)
return -EINVAL;
strscpy(uinfo->value.enumerated.name, kctl->items[i].item,
sizeof(uinfo->value.enumerated.name));
break;
}
return 0;
}
/**
* virtsnd_kctl_get() - Read the value from the control.
* @kcontrol: ALSA control element.
* @uvalue: Element value.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_kctl_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *uvalue)
{
struct virtio_snd *snd = kcontrol->private_data;
struct virtio_snd_ctl_info *kinfo =
&snd->kctl_infos[kcontrol->private_value];
unsigned int type = le32_to_cpu(kinfo->type);
unsigned int count = le32_to_cpu(kinfo->count);
struct virtio_snd_msg *msg;
struct virtio_snd_ctl_hdr *hdr;
struct virtio_snd_ctl_value *kvalue;
size_t request_size = sizeof(*hdr);
size_t response_size = sizeof(struct virtio_snd_hdr) + sizeof(*kvalue);
unsigned int i;
int rc;
msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
if (!msg)
return -ENOMEM;
virtsnd_ctl_msg_ref(msg);
hdr = virtsnd_ctl_msg_request(msg);
hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_READ);
hdr->control_id = cpu_to_le32(kcontrol->private_value);
rc = virtsnd_ctl_msg_send_sync(snd, msg);
if (rc)
goto on_failure;
kvalue = (void *)((u8 *)virtsnd_ctl_msg_response(msg) +
sizeof(struct virtio_snd_hdr));
switch (type) {
case VIRTIO_SND_CTL_TYPE_BOOLEAN:
case VIRTIO_SND_CTL_TYPE_INTEGER:
for (i = 0; i < count; ++i)
uvalue->value.integer.value[i] =
le32_to_cpu(kvalue->value.integer[i]);
break;
case VIRTIO_SND_CTL_TYPE_INTEGER64:
for (i = 0; i < count; ++i)
uvalue->value.integer64.value[i] =
le64_to_cpu(kvalue->value.integer64[i]);
break;
case VIRTIO_SND_CTL_TYPE_ENUMERATED:
for (i = 0; i < count; ++i)
uvalue->value.enumerated.item[i] =
le32_to_cpu(kvalue->value.enumerated[i]);
break;
case VIRTIO_SND_CTL_TYPE_BYTES:
memcpy(uvalue->value.bytes.data, kvalue->value.bytes, count);
break;
case VIRTIO_SND_CTL_TYPE_IEC958:
memcpy(&uvalue->value.iec958, &kvalue->value.iec958,
sizeof(uvalue->value.iec958));
break;
}
on_failure:
virtsnd_ctl_msg_unref(msg);
return rc;
}
/**
* virtsnd_kctl_put() - Write the value to the control.
* @kcontrol: ALSA control element.
* @uvalue: Element value.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_kctl_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *uvalue)
{
struct virtio_snd *snd = kcontrol->private_data;
struct virtio_snd_ctl_info *kinfo =
&snd->kctl_infos[kcontrol->private_value];
unsigned int type = le32_to_cpu(kinfo->type);
unsigned int count = le32_to_cpu(kinfo->count);
struct virtio_snd_msg *msg;
struct virtio_snd_ctl_hdr *hdr;
struct virtio_snd_ctl_value *kvalue;
size_t request_size = sizeof(*hdr) + sizeof(*kvalue);
size_t response_size = sizeof(struct virtio_snd_hdr);
unsigned int i;
msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = virtsnd_ctl_msg_request(msg);
hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_WRITE);
hdr->control_id = cpu_to_le32(kcontrol->private_value);
kvalue = (void *)((u8 *)hdr + sizeof(*hdr));
switch (type) {
case VIRTIO_SND_CTL_TYPE_BOOLEAN:
case VIRTIO_SND_CTL_TYPE_INTEGER:
for (i = 0; i < count; ++i)
kvalue->value.integer[i] =
cpu_to_le32(uvalue->value.integer.value[i]);
break;
case VIRTIO_SND_CTL_TYPE_INTEGER64:
for (i = 0; i < count; ++i)
kvalue->value.integer64[i] =
cpu_to_le64(uvalue->value.integer64.value[i]);
break;
case VIRTIO_SND_CTL_TYPE_ENUMERATED:
for (i = 0; i < count; ++i)
kvalue->value.enumerated[i] =
cpu_to_le32(uvalue->value.enumerated.item[i]);
break;
case VIRTIO_SND_CTL_TYPE_BYTES:
memcpy(kvalue->value.bytes, uvalue->value.bytes.data, count);
break;
case VIRTIO_SND_CTL_TYPE_IEC958:
memcpy(&kvalue->value.iec958, &uvalue->value.iec958,
sizeof(kvalue->value.iec958));
break;
}
return virtsnd_ctl_msg_send_sync(snd, msg);
}
/**
* virtsnd_kctl_tlv_op() - Perform an operation on the control's metadata.
* @kcontrol: ALSA control element.
* @op_flag: Operation code (SNDRV_CTL_TLV_OP_XXX).
* @size: Size of the TLV data in bytes.
* @utlv: TLV data.
*
* Context: Process context.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_kctl_tlv_op(struct snd_kcontrol *kcontrol, int op_flag,
unsigned int size, unsigned int __user *utlv)
{
struct virtio_snd *snd = kcontrol->private_data;
struct virtio_snd_msg *msg;
struct virtio_snd_ctl_hdr *hdr;
unsigned int *tlv;
struct scatterlist sg;
int rc;
msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), sizeof(struct virtio_snd_hdr),
GFP_KERNEL);
if (!msg)
return -ENOMEM;
tlv = kzalloc(size, GFP_KERNEL);
if (!tlv) {
virtsnd_ctl_msg_unref(msg);
return -ENOMEM;
}
sg_init_one(&sg, tlv, size);
hdr = virtsnd_ctl_msg_request(msg);
hdr->control_id = cpu_to_le32(kcontrol->private_value);
switch (op_flag) {
case SNDRV_CTL_TLV_OP_READ:
hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_READ);
rc = virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
if (!rc) {
if (copy_to_user(utlv, tlv, size))
rc = -EFAULT;
}
break;
case SNDRV_CTL_TLV_OP_WRITE:
case SNDRV_CTL_TLV_OP_CMD:
if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_WRITE);
else
hdr->hdr.code =
cpu_to_le32(VIRTIO_SND_R_CTL_TLV_COMMAND);
if (copy_from_user(tlv, utlv, size))
rc = -EFAULT;
else
rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
break;
}
kfree(tlv);
return rc;
}
/**
* virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
* @snd: VirtIO sound device.
* @cid: Control element ID.
*
* This function is called during initial device initialization.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
static int virtsnd_kctl_get_enum_items(struct virtio_snd *snd, unsigned int cid)
{
struct virtio_device *vdev = snd->vdev;
struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
struct virtio_kctl *kctl = &snd->kctls[cid];
struct virtio_snd_msg *msg;
struct virtio_snd_ctl_hdr *hdr;
unsigned int n = le32_to_cpu(kinfo->value.enumerated.items);
struct scatterlist sg;
msg = virtsnd_ctl_msg_alloc(sizeof(*hdr),
sizeof(struct virtio_snd_hdr), GFP_KERNEL);
if (!msg)
return -ENOMEM;
kctl->items = devm_kcalloc(&vdev->dev, n, sizeof(*kctl->items),
GFP_KERNEL);
if (!kctl->items) {
virtsnd_ctl_msg_unref(msg);
return -ENOMEM;
}
sg_init_one(&sg, kctl->items, n * sizeof(*kctl->items));
hdr = virtsnd_ctl_msg_request(msg);
hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_ENUM_ITEMS);
hdr->control_id = cpu_to_le32(cid);
return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false);
}
/**
* virtsnd_kctl_parse_cfg() - Parse the control element configuration.
* @snd: VirtIO sound device.
*
* This function is called during initial device initialization.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
int virtsnd_kctl_parse_cfg(struct virtio_snd *snd)
{
struct virtio_device *vdev = snd->vdev;
u32 i;
int rc;
virtio_cread_le(vdev, struct virtio_snd_config, controls,
&snd->nkctls);
if (!snd->nkctls)
return 0;
snd->kctl_infos = devm_kcalloc(&vdev->dev, snd->nkctls,
sizeof(*snd->kctl_infos), GFP_KERNEL);
if (!snd->kctl_infos)
return -ENOMEM;
snd->kctls = devm_kcalloc(&vdev->dev, snd->nkctls, sizeof(*snd->kctls),
GFP_KERNEL);
if (!snd->kctls)
return -ENOMEM;
rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CTL_INFO, 0, snd->nkctls,
sizeof(*snd->kctl_infos), snd->kctl_infos);
if (rc)
return rc;
for (i = 0; i < snd->nkctls; ++i) {
struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[i];
unsigned int type = le32_to_cpu(kinfo->type);
if (type == VIRTIO_SND_CTL_TYPE_ENUMERATED) {
rc = virtsnd_kctl_get_enum_items(snd, i);
if (rc)
return rc;
}
}
return 0;
}
/**
* virtsnd_kctl_build_devs() - Build ALSA control elements.
* @snd: VirtIO sound device.
*
* Context: Any context that permits to sleep.
* Return: 0 on success, -errno on failure.
*/
int virtsnd_kctl_build_devs(struct virtio_snd *snd)
{
unsigned int cid;
for (cid = 0; cid < snd->nkctls; ++cid) {
struct virtio_snd_ctl_info *kinfo = &snd->kctl_infos[cid];
struct virtio_kctl *kctl = &snd->kctls[cid];
struct snd_kcontrol_new kctl_new;
unsigned int i;
int rc;
memset(&kctl_new, 0, sizeof(kctl_new));
kctl_new.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
kctl_new.name = kinfo->name;
kctl_new.index = le32_to_cpu(kinfo->index);
for (i = 0; i < ARRAY_SIZE(g_v2a_access_map); ++i)
if (le32_to_cpu(kinfo->access) & (1 << i))
kctl_new.access |= g_v2a_access_map[i];
if (kctl_new.access & (SNDRV_CTL_ELEM_ACCESS_TLV_READ |
SNDRV_CTL_ELEM_ACCESS_TLV_WRITE |
SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND)) {
kctl_new.access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
kctl_new.tlv.c = virtsnd_kctl_tlv_op;
}
kctl_new.info = virtsnd_kctl_info;
kctl_new.get = virtsnd_kctl_get;
kctl_new.put = virtsnd_kctl_put;
kctl_new.private_value = cid;
kctl->kctl = snd_ctl_new1(&kctl_new, snd);
if (!kctl->kctl)
return -ENOMEM;
rc = snd_ctl_add(snd->card, kctl->kctl);
if (rc)
return rc;
}
return 0;
}
/**
* virtsnd_kctl_event() - Handle the control element event notification.
* @snd: VirtIO sound device.
* @event: VirtIO sound event.
*
* Context: Interrupt context.
*/
void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event)
{
struct virtio_snd_ctl_event *kevent =
(struct virtio_snd_ctl_event *)event;
struct virtio_kctl *kctl;
unsigned int cid = le16_to_cpu(kevent->control_id);
unsigned int mask = 0;
unsigned int i;
if (cid >= snd->nkctls)
return;
for (i = 0; i < ARRAY_SIZE(g_v2a_mask_map); ++i)
if (le16_to_cpu(kevent->mask) & (1 << i))
mask |= g_v2a_mask_map[i];
kctl = &snd->kctls[cid];
snd_ctl_notify(snd->card, mask, &kctl->kctl->id);
}