// 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 = snd_kcontrol_chip(kcontrol);
        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 = snd_kcontrol_chip(kcontrol);
        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 = snd_kcontrol_chip(kcontrol);
        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 = snd_kcontrol_chip(kcontrol);
        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) {
                rc = -ENOMEM;
                goto on_msg_unref;
        }

        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;
                        goto on_msg_unref;
                } else {
                        rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
                }

                break;
        default:
                rc = -EINVAL;
                /* We never get here - we listed all values for op_flag */
                WARN_ON(1);
                goto on_msg_unref;
        }
        kfree(tlv);
        return rc;

on_msg_unref:
        virtsnd_ctl_msg_unref(msg);
        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);
}