// SPDX-License-Identifier: GPL-2.0-only
/*
 * K3 DTHE V2 crypto accelerator driver
 *
 * Copyright (C) Texas Instruments 2025 - https://www.ti.com
 * Author: T Pratham <t-pratham@ti.com>
 */

#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <crypto/engine.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>

#include "dthev2-common.h"

#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/scatterlist.h>

#define DRIVER_NAME     "dthev2"

static struct dthe_list dthe_dev_list = {
        .dev_list = LIST_HEAD_INIT(dthe_dev_list.dev_list),
        .lock = __SPIN_LOCK_UNLOCKED(dthe_dev_list.lock),
};

struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx)
{
        struct dthe_data *dev_data;

        if (ctx->dev_data)
                return ctx->dev_data;

        spin_lock_bh(&dthe_dev_list.lock);
        dev_data = list_first_entry(&dthe_dev_list.dev_list, struct dthe_data, list);
        if (dev_data)
                list_move_tail(&dev_data->list, &dthe_dev_list.dev_list);
        spin_unlock_bh(&dthe_dev_list.lock);

        return dev_data;
}

static int dthe_dma_init(struct dthe_data *dev_data)
{
        int ret;
        struct dma_slave_config cfg;

        dev_data->dma_aes_rx = NULL;
        dev_data->dma_aes_tx = NULL;
        dev_data->dma_sha_tx = NULL;

        dev_data->dma_aes_rx = dma_request_chan(dev_data->dev, "rx");
        if (IS_ERR(dev_data->dma_aes_rx)) {
                return dev_err_probe(dev_data->dev, PTR_ERR(dev_data->dma_aes_rx),
                                     "Unable to request rx DMA channel\n");
        }

        dev_data->dma_aes_tx = dma_request_chan(dev_data->dev, "tx1");
        if (IS_ERR(dev_data->dma_aes_tx)) {
                ret = dev_err_probe(dev_data->dev, PTR_ERR(dev_data->dma_aes_tx),
                                    "Unable to request tx1 DMA channel\n");
                goto err_dma_aes_tx;
        }

        dev_data->dma_sha_tx = dma_request_chan(dev_data->dev, "tx2");
        if (IS_ERR(dev_data->dma_sha_tx)) {
                ret = dev_err_probe(dev_data->dev, PTR_ERR(dev_data->dma_sha_tx),
                                    "Unable to request tx2 DMA channel\n");
                goto err_dma_sha_tx;
        }

        memzero_explicit(&cfg, sizeof(cfg));

        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.src_maxburst = 4;

        ret = dmaengine_slave_config(dev_data->dma_aes_rx, &cfg);
        if (ret) {
                dev_err(dev_data->dev, "Can't configure IN dmaengine slave: %d\n", ret);
                goto err_dma_config;
        }

        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.dst_maxburst = 4;

        ret = dmaengine_slave_config(dev_data->dma_aes_tx, &cfg);
        if (ret) {
                dev_err(dev_data->dev, "Can't configure OUT dmaengine slave: %d\n", ret);
                goto err_dma_config;
        }

        return 0;

err_dma_config:
        dma_release_channel(dev_data->dma_sha_tx);
err_dma_sha_tx:
        dma_release_channel(dev_data->dma_aes_tx);
err_dma_aes_tx:
        dma_release_channel(dev_data->dma_aes_rx);

        return ret;
}

static int dthe_register_algs(void)
{
        return dthe_register_aes_algs();
}

static void dthe_unregister_algs(void)
{
        dthe_unregister_aes_algs();
}

static int dthe_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct dthe_data *dev_data;
        int ret;

        dev_data = devm_kzalloc(dev, sizeof(*dev_data), GFP_KERNEL);
        if (!dev_data)
                return -ENOMEM;

        dev_data->dev = dev;
        dev_data->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(dev_data->regs))
                return PTR_ERR(dev_data->regs);

        platform_set_drvdata(pdev, dev_data);

        spin_lock(&dthe_dev_list.lock);
        list_add(&dev_data->list, &dthe_dev_list.dev_list);
        spin_unlock(&dthe_dev_list.lock);

        ret = dthe_dma_init(dev_data);
        if (ret)
                goto probe_dma_err;

        dev_data->engine = crypto_engine_alloc_init(dev, 1);
        if (!dev_data->engine) {
                ret = -ENOMEM;
                goto probe_engine_err;
        }

        ret = crypto_engine_start(dev_data->engine);
        if (ret) {
                dev_err(dev, "Failed to start crypto engine\n");
                goto probe_engine_start_err;
        }

        ret = dthe_register_algs();
        if (ret) {
                dev_err(dev, "Failed to register algs\n");
                goto probe_engine_start_err;
        }

        return 0;

probe_engine_start_err:
        crypto_engine_exit(dev_data->engine);
probe_engine_err:
        dma_release_channel(dev_data->dma_aes_rx);
        dma_release_channel(dev_data->dma_aes_tx);
        dma_release_channel(dev_data->dma_sha_tx);
probe_dma_err:
        spin_lock(&dthe_dev_list.lock);
        list_del(&dev_data->list);
        spin_unlock(&dthe_dev_list.lock);

        return ret;
}

static void dthe_remove(struct platform_device *pdev)
{
        struct dthe_data *dev_data = platform_get_drvdata(pdev);

        spin_lock(&dthe_dev_list.lock);
        list_del(&dev_data->list);
        spin_unlock(&dthe_dev_list.lock);

        dthe_unregister_algs();

        crypto_engine_exit(dev_data->engine);

        dma_release_channel(dev_data->dma_aes_rx);
        dma_release_channel(dev_data->dma_aes_tx);
        dma_release_channel(dev_data->dma_sha_tx);
}

static const struct of_device_id dthe_of_match[] = {
        { .compatible = "ti,am62l-dthev2", },
        {},
};
MODULE_DEVICE_TABLE(of, dthe_of_match);

static struct platform_driver dthe_driver = {
        .probe  = dthe_probe,
        .remove = dthe_remove,
        .driver = {
                .name           = DRIVER_NAME,
                .of_match_table = dthe_of_match,
        },
};

module_platform_driver(dthe_driver);

MODULE_AUTHOR("T Pratham <t-pratham@ti.com>");
MODULE_DESCRIPTION("Texas Instruments DTHE V2 driver");
MODULE_LICENSE("GPL");