// SPDX-License-Identifier: GPL-2.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES.
// All rights reserved.
//
// ADMA bandwidth calculation

#include <linux/interconnect.h>
#include <linux/module.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include "tegra_isomgr_bw.h"
#include "tegra210_admaif.h"

#define MAX_SAMPLE_RATE         192     /* KHz*/
#define MAX_BYTES_PER_SAMPLE    4

int tegra_isomgr_adma_setbw(struct snd_pcm_substream *substream,
                            struct snd_soc_dai *dai, bool is_running)
{
        struct device *dev = dai->dev;
        struct tegra_admaif *admaif = snd_soc_dai_get_drvdata(dai);
        struct tegra_adma_isomgr *adma_isomgr = admaif->adma_isomgr;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm *pcm = substream->pcm;
        u32 type = substream->stream, bandwidth = 0;
        int sample_bytes;

        if (!adma_isomgr)
                return 0;

        if (!runtime || !pcm)
                return -EINVAL;

        if (pcm->device >= adma_isomgr->max_pcm_device) {
                dev_err(dev, "%s: PCM device number %d is greater than %d\n", __func__,
                        pcm->device, adma_isomgr->max_pcm_device);
                return -EINVAL;
        }

        /*
         * No action if  stream is running and bandwidth is already set or
         * stream is not running and bandwidth is already reset
         */
        if ((adma_isomgr->bw_per_dev[type][pcm->device] && is_running) ||
            (!adma_isomgr->bw_per_dev[type][pcm->device] && !is_running))
                return 0;

        if (is_running) {
                sample_bytes = snd_pcm_format_width(runtime->format) / 8;
                if (sample_bytes < 0)
                        return sample_bytes;

                /* KB/s kilo bytes per sec */
                bandwidth = runtime->channels * (runtime->rate / 1000) *
                                sample_bytes;
        }

        mutex_lock(&adma_isomgr->mutex);

        if (is_running) {
                if (bandwidth + adma_isomgr->current_bandwidth > adma_isomgr->max_bw)
                        bandwidth = adma_isomgr->max_bw - adma_isomgr->current_bandwidth;

                adma_isomgr->current_bandwidth += bandwidth;
        } else {
                adma_isomgr->current_bandwidth -= adma_isomgr->bw_per_dev[type][pcm->device];
        }

        mutex_unlock(&adma_isomgr->mutex);

        adma_isomgr->bw_per_dev[type][pcm->device] = bandwidth;

        dev_dbg(dev, "Setting up bandwidth to %d KBps\n", adma_isomgr->current_bandwidth);

        return icc_set_bw(adma_isomgr->icc_path_handle,
                          adma_isomgr->current_bandwidth, adma_isomgr->max_bw);
}

int tegra_isomgr_adma_register(struct device *dev)
{
        struct tegra_admaif *admaif = dev_get_drvdata(dev);
        struct tegra_adma_isomgr *adma_isomgr;
        int i;

        adma_isomgr = devm_kzalloc(dev, sizeof(struct tegra_adma_isomgr), GFP_KERNEL);
        if (!adma_isomgr)
                return -ENOMEM;

        adma_isomgr->icc_path_handle = devm_of_icc_get(dev, "write");
        if (IS_ERR(adma_isomgr->icc_path_handle))
                return dev_err_probe(dev, PTR_ERR(adma_isomgr->icc_path_handle),
                                "failed to acquire interconnect path\n");

        /* Either INTERCONNECT config OR interconnect property is not defined */
        if (!adma_isomgr->icc_path_handle) {
                devm_kfree(dev, adma_isomgr);
                return 0;
        }

        adma_isomgr->max_pcm_device = admaif->soc_data->num_ch;
        adma_isomgr->max_bw = STREAM_TYPE * MAX_SAMPLE_RATE * MAX_BYTES_PER_SAMPLE *
                              admaif->soc_data->max_stream_ch * adma_isomgr->max_pcm_device;

        for (i = 0; i < STREAM_TYPE; i++) {
                adma_isomgr->bw_per_dev[i] = devm_kzalloc(dev, adma_isomgr->max_pcm_device *
                                                          sizeof(u32), GFP_KERNEL);
                if (!adma_isomgr->bw_per_dev[i])
                        return -ENOMEM;
        }

        adma_isomgr->current_bandwidth = 0;
        mutex_init(&adma_isomgr->mutex);
        admaif->adma_isomgr = adma_isomgr;

        return 0;
}

void tegra_isomgr_adma_unregister(struct device *dev)
{
        struct tegra_admaif *admaif = dev_get_drvdata(dev);

        if (!admaif->adma_isomgr)
                return;

        mutex_destroy(&admaif->adma_isomgr->mutex);
}

MODULE_AUTHOR("Mohan Kumar <mkumard@nvidia.com>");
MODULE_DESCRIPTION("Tegra ADMA Bandwidth Request driver");
MODULE_LICENSE("GPL");