Implementation of support for audio controls in accordance with the proposed extension of the virtio sound device specification [1].

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 --- include/uapi/linux/virtio_snd.h | 154 +++++++++++ sound/virtio/Makefile | 1 + sound/virtio/virtio_card.c | 21 ++ sound/virtio/virtio_card.h | 22 ++ sound/virtio/virtio_kctl.c | 464 ++++++++++++++++++++++++++++++++ 5 files changed, 662 insertions(+) create mode 100644 sound/virtio/virtio_kctl.c

diff --git a/include/uapi/linux/virtio_snd.h b/include/uapi/linux/virtio_snd.h index dfe49547a7b0..5f4100c2cf04 100644 --- a/include/uapi/linux/virtio_snd.h +++ b/include/uapi/linux/virtio_snd.h @@ -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 */ diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile index 2742bddb8874..a839f8c8b5e6 100644 --- a/sound/virtio/Makefile +++ b/sound/virtio/Makefile @@ -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 diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c index e2847c040f75..61df3476cf70 100644 --- a/sound/virtio/virtio_card.c +++ b/sound/virtio/virtio_card.c @@ -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; } }

@@ -235,6 +238,12 @@ 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) @@ -253,6 +262,12 @@ 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); }

@@ -419,10 +434,16 @@ 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, diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h index 86ef3941895e..3ceee4e416fc 100644 --- a/sound/virtio/virtio_card.h +++ b/sound/virtio/virtio_card.h @@ -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 */ diff --git a/sound/virtio/virtio_kctl.c b/sound/virtio/virtio_kctl.c new file mode 100644 index 000000000000..16c48abe0ca1 --- /dev/null +++ b/sound/virtio/virtio_kctl.c @@ -0,0 +1,464 @@ +// 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: + i = uinfo->value.enumerated.item; + if (i >= le32_to_cpu(kinfo->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); +}