// SPDX-License-Identifier: GPL-2.0
// hdac_component.c - routines for sync between HD-A core and DRM driver

#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/component.h>
#include <sound/core.h>
#include <sound/hdaudio.h>
#include <sound/hda_component.h>
#include <sound/hda_register.h>

static void hdac_acomp_release(struct device *dev, void *res)
{
}

static struct drm_audio_component *hdac_get_acomp(struct device *dev)
{
        return devres_find(dev, hdac_acomp_release, NULL, NULL);
}

/**
 * snd_hdac_set_codec_wakeup - Enable / disable HDMI/DP codec wakeup
 * @bus: HDA core bus
 * @enable: enable or disable the wakeup
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function should be called during the chip reset, also called at
 * resume for updating STATESTS register read.
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
{
        struct drm_audio_component *acomp = bus->audio_component;

        if (!acomp || !acomp->ops)
                return -ENODEV;

        if (!acomp->ops->codec_wake_override)
                return 0;

        dev_dbg(bus->dev, "%s codec wakeup\n",
                enable ? "enable" : "disable");

        acomp->ops->codec_wake_override(acomp->dev, enable);

        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);

/**
 * snd_hdac_display_power - Power up / down the power refcount
 * @bus: HDA core bus
 * @enable: power up or down
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function manages a refcount and calls the get_power() and
 * put_power() ops accordingly, toggling the codec wakeup, too.
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
{
        struct drm_audio_component *acomp = bus->audio_component;

        if (!acomp || !acomp->ops)
                return -ENODEV;

        dev_dbg(bus->dev, "display power %s\n",
                enable ? "enable" : "disable");

        if (enable) {
                if (!bus->drm_power_refcount++) {
                        if (acomp->ops->get_power)
                                acomp->ops->get_power(acomp->dev);
                        snd_hdac_set_codec_wakeup(bus, true);
                        snd_hdac_set_codec_wakeup(bus, false);
                }
        } else {
                WARN_ON(!bus->drm_power_refcount);
                if (!--bus->drm_power_refcount)
                        if (acomp->ops->put_power)
                                acomp->ops->put_power(acomp->dev);
        }

        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_display_power);

/**
 * snd_hdac_sync_audio_rate - Set N/CTS based on the sample rate
 * @codec: HDA codec
 * @nid: the pin widget NID
 * @dev_id: device identifier
 * @rate: the sample rate to set
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function sets N/CTS value based on the given sample rate.
 * Returns zero for success, or a negative error code.
 */
int snd_hdac_sync_audio_rate(struct hdac_device *codec, hda_nid_t nid,
                             int dev_id, int rate)
{
        struct hdac_bus *bus = codec->bus;
        struct drm_audio_component *acomp = bus->audio_component;
        int port, pipe;

        if (!acomp || !acomp->ops || !acomp->ops->sync_audio_rate)
                return -ENODEV;
        port = nid;
        if (acomp->audio_ops && acomp->audio_ops->pin2port) {
                port = acomp->audio_ops->pin2port(codec, nid);
                if (port < 0)
                        return -EINVAL;
        }
        pipe = dev_id;
        return acomp->ops->sync_audio_rate(acomp->dev, port, pipe, rate);
}
EXPORT_SYMBOL_GPL(snd_hdac_sync_audio_rate);

/**
 * snd_hdac_acomp_get_eld - Get the audio state and ELD via component
 * @codec: HDA codec
 * @nid: the pin widget NID
 * @dev_id: device identifier
 * @audio_enabled: the pointer to store the current audio state
 * @buffer: the buffer pointer to store ELD bytes
 * @max_bytes: the max bytes to be stored on @buffer
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function queries the current state of the audio on the given
 * digital port and fetches the ELD bytes onto the given buffer.
 * It returns the number of bytes for the total ELD data, zero for
 * invalid ELD, or a negative error code.
 *
 * The return size is the total bytes required for the whole ELD bytes,
 * thus it may be over @max_bytes.  If it's over @max_bytes, it implies
 * that only a part of ELD bytes have been fetched.
 */
int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
                           bool *audio_enabled, char *buffer, int max_bytes)
{
        struct hdac_bus *bus = codec->bus;
        struct drm_audio_component *acomp = bus->audio_component;
        int port, pipe;

        if (!acomp || !acomp->ops || !acomp->ops->get_eld)
                return -ENODEV;

        port = nid;
        if (acomp->audio_ops && acomp->audio_ops->pin2port) {
                port = acomp->audio_ops->pin2port(codec, nid);
                if (port < 0)
                        return -EINVAL;
        }
        pipe = dev_id;
        return acomp->ops->get_eld(acomp->dev, port, pipe, audio_enabled,
                                   buffer, max_bytes);
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_get_eld);

static int hdac_component_master_bind(struct device *dev)
{
        struct drm_audio_component *acomp = hdac_get_acomp(dev);
        int ret;

        if (WARN_ON(!acomp))
                return -EINVAL;

        ret = component_bind_all(dev, acomp);
        if (ret < 0)
                return ret;

        if (WARN_ON(!(acomp->dev && acomp->ops))) {
                ret = -EINVAL;
                goto out_unbind;
        }

        /* pin the module to avoid dynamic unbinding, but only if given */
        if (!try_module_get(acomp->ops->owner)) {
                ret = -ENODEV;
                goto out_unbind;
        }

        if (acomp->audio_ops && acomp->audio_ops->master_bind) {
                ret = acomp->audio_ops->master_bind(dev, acomp);
                if (ret < 0)
                        goto module_put;
        }

        return 0;

 module_put:
        module_put(acomp->ops->owner);
out_unbind:
        component_unbind_all(dev, acomp);

        return ret;
}

static void hdac_component_master_unbind(struct device *dev)
{
        struct drm_audio_component *acomp = hdac_get_acomp(dev);

        if (acomp->audio_ops && acomp->audio_ops->master_unbind)
                acomp->audio_ops->master_unbind(dev, acomp);
        module_put(acomp->ops->owner);
        component_unbind_all(dev, acomp);
        WARN_ON(acomp->ops || acomp->dev);
}

static const struct component_master_ops hdac_component_master_ops = {
        .bind = hdac_component_master_bind,
        .unbind = hdac_component_master_unbind,
};

/**
 * snd_hdac_acomp_register_notifier - Register audio component ops
 * @bus: HDA core bus
 * @aops: audio component ops
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function sets the given ops to be called by the graphics driver.
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_acomp_register_notifier(struct hdac_bus *bus,
                                    const struct drm_audio_component_audio_ops *aops)
{
        if (!bus->audio_component)
                return -ENODEV;

        bus->audio_component->audio_ops = aops;
        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_register_notifier);

/**
 * snd_hdac_acomp_init - Initialize audio component
 * @bus: HDA core bus
 * @match_master: match function for finding components
 * @extra_size: Extra bytes to allocate
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function initializes and sets up the audio component to communicate
 * with graphics driver.
 *
 * Unlike snd_hdac_i915_init(), this function doesn't synchronize with the
 * binding with the DRM component.  Each caller needs to sync via master_bind
 * audio_ops.
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_acomp_init(struct hdac_bus *bus,
                        const struct drm_audio_component_audio_ops *aops,
                        int (*match_master)(struct device *, void *),
                        size_t extra_size)
{
        struct component_match *match = NULL;
        struct device *dev = bus->dev;
        struct drm_audio_component *acomp;
        int ret;

        if (WARN_ON(hdac_get_acomp(dev)))
                return -EBUSY;

        acomp = devres_alloc(hdac_acomp_release, sizeof(*acomp) + extra_size,
                             GFP_KERNEL);
        if (!acomp)
                return -ENOMEM;
        acomp->audio_ops = aops;
        bus->audio_component = acomp;
        devres_add(dev, acomp);

        component_match_add(dev, &match, match_master, bus);
        ret = component_master_add_with_match(dev, &hdac_component_master_ops,
                                              match);
        if (ret < 0)
                goto out_err;

        return 0;

out_err:
        bus->audio_component = NULL;
        devres_destroy(dev, hdac_acomp_release, NULL, NULL);
        dev_info(dev, "failed to add audio component master (%d)\n", ret);

        return ret;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_init);

/**
 * snd_hdac_acomp_exit - Finalize audio component
 * @bus: HDA core bus
 *
 * This function is supposed to be used only by a HD-audio controller
 * driver that needs the interaction with graphics driver.
 *
 * This function releases the audio component that has been used.
 *
 * Returns zero for success or a negative error code.
 */
int snd_hdac_acomp_exit(struct hdac_bus *bus)
{
        struct device *dev = bus->dev;
        struct drm_audio_component *acomp = bus->audio_component;

        if (!acomp)
                return 0;

        WARN_ON(bus->drm_power_refcount);
        if (bus->drm_power_refcount > 0 && acomp->ops)
                acomp->ops->put_power(acomp->dev);

        component_master_del(dev, &hdac_component_master_ops);

        bus->audio_component = NULL;
        devres_destroy(dev, hdac_acomp_release, NULL, NULL);

        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_acomp_exit);