/*
 * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/sha.h>

#include "core.h"
#include "cipher.h"
#include "sha.h"

#define QCE_MAJOR_VERSION5      0x05
#define QCE_QUEUE_LENGTH        1

static const struct qce_algo_ops *qce_ops[] = {
        &ablkcipher_ops,
        &ahash_ops,
};

static void qce_unregister_algs(struct qce_device *qce)
{
        const struct qce_algo_ops *ops;
        int i;

        for (i = 0; i < ARRAY_SIZE(qce_ops); i++) {
                ops = qce_ops[i];
                ops->unregister_algs(qce);
        }
}

static int qce_register_algs(struct qce_device *qce)
{
        const struct qce_algo_ops *ops;
        int i, ret = -ENODEV;

        for (i = 0; i < ARRAY_SIZE(qce_ops); i++) {
                ops = qce_ops[i];
                ret = ops->register_algs(qce);
                if (ret)
                        break;
        }

        return ret;
}

static int qce_handle_request(struct crypto_async_request *async_req)
{
        int ret = -EINVAL, i;
        const struct qce_algo_ops *ops;
        u32 type = crypto_tfm_alg_type(async_req->tfm);

        for (i = 0; i < ARRAY_SIZE(qce_ops); i++) {
                ops = qce_ops[i];
                if (type != ops->type)
                        continue;
                ret = ops->async_req_handle(async_req);
                break;
        }

        return ret;
}

static int qce_handle_queue(struct qce_device *qce,
                            struct crypto_async_request *req)
{
        struct crypto_async_request *async_req, *backlog;
        unsigned long flags;
        int ret = 0, err;

        spin_lock_irqsave(&qce->lock, flags);

        if (req)
                ret = crypto_enqueue_request(&qce->queue, req);

        /* busy, do not dequeue request */
        if (qce->req) {
                spin_unlock_irqrestore(&qce->lock, flags);
                return ret;
        }

        backlog = crypto_get_backlog(&qce->queue);
        async_req = crypto_dequeue_request(&qce->queue);
        if (async_req)
                qce->req = async_req;

        spin_unlock_irqrestore(&qce->lock, flags);

        if (!async_req)
                return ret;

        if (backlog) {
                spin_lock_bh(&qce->lock);
                backlog->complete(backlog, -EINPROGRESS);
                spin_unlock_bh(&qce->lock);
        }

        err = qce_handle_request(async_req);
        if (err) {
                qce->result = err;
                tasklet_schedule(&qce->done_tasklet);
        }

        return ret;
}

static void qce_tasklet_req_done(unsigned long data)
{
        struct qce_device *qce = (struct qce_device *)data;
        struct crypto_async_request *req;
        unsigned long flags;

        spin_lock_irqsave(&qce->lock, flags);
        req = qce->req;
        qce->req = NULL;
        spin_unlock_irqrestore(&qce->lock, flags);

        if (req)
                req->complete(req, qce->result);

        qce_handle_queue(qce, NULL);
}

static int qce_async_request_enqueue(struct qce_device *qce,
                                     struct crypto_async_request *req)
{
        return qce_handle_queue(qce, req);
}

static void qce_async_request_done(struct qce_device *qce, int ret)
{
        qce->result = ret;
        tasklet_schedule(&qce->done_tasklet);
}

static int qce_check_version(struct qce_device *qce)
{
        u32 major, minor, step;

        qce_get_version(qce, &major, &minor, &step);

        /*
         * the driver does not support v5 with minor 0 because it has special
         * alignment requirements.
         */
        if (major != QCE_MAJOR_VERSION5 || minor == 0)
                return -ENODEV;

        qce->burst_size = QCE_BAM_BURST_SIZE;
        qce->pipe_pair_id = 1;

        dev_dbg(qce->dev, "Crypto device found, version %d.%d.%d\n",
                major, minor, step);

        return 0;
}

static int qce_crypto_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct qce_device *qce;
        struct resource *res;
        int ret;

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

        qce->dev = dev;
        platform_set_drvdata(pdev, qce);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        qce->base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(qce->base))
                return PTR_ERR(qce->base);

        ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
        if (ret < 0)
                return ret;

        qce->core = devm_clk_get(qce->dev, "core");
        if (IS_ERR(qce->core))
                return PTR_ERR(qce->core);

        qce->iface = devm_clk_get(qce->dev, "iface");
        if (IS_ERR(qce->iface))
                return PTR_ERR(qce->iface);

        qce->bus = devm_clk_get(qce->dev, "bus");
        if (IS_ERR(qce->bus))
                return PTR_ERR(qce->bus);

        ret = clk_prepare_enable(qce->core);
        if (ret)
                return ret;

        ret = clk_prepare_enable(qce->iface);
        if (ret)
                goto err_clks_core;

        ret = clk_prepare_enable(qce->bus);
        if (ret)
                goto err_clks_iface;

        ret = qce_dma_request(qce->dev, &qce->dma);
        if (ret)
                goto err_clks;

        ret = qce_check_version(qce);
        if (ret)
                goto err_clks;

        spin_lock_init(&qce->lock);
        tasklet_init(&qce->done_tasklet, qce_tasklet_req_done,
                     (unsigned long)qce);
        crypto_init_queue(&qce->queue, QCE_QUEUE_LENGTH);

        qce->async_req_enqueue = qce_async_request_enqueue;
        qce->async_req_done = qce_async_request_done;

        ret = qce_register_algs(qce);
        if (ret)
                goto err_dma;

        return 0;

err_dma:
        qce_dma_release(&qce->dma);
err_clks:
        clk_disable_unprepare(qce->bus);
err_clks_iface:
        clk_disable_unprepare(qce->iface);
err_clks_core:
        clk_disable_unprepare(qce->core);
        return ret;
}

static int qce_crypto_remove(struct platform_device *pdev)
{
        struct qce_device *qce = platform_get_drvdata(pdev);

        tasklet_kill(&qce->done_tasklet);
        qce_unregister_algs(qce);
        qce_dma_release(&qce->dma);
        clk_disable_unprepare(qce->bus);
        clk_disable_unprepare(qce->iface);
        clk_disable_unprepare(qce->core);
        return 0;
}

static const struct of_device_id qce_crypto_of_match[] = {
        { .compatible = "qcom,crypto-v5.1", },
        {}
};
MODULE_DEVICE_TABLE(of, qce_crypto_of_match);

static struct platform_driver qce_crypto_driver = {
        .probe = qce_crypto_probe,
        .remove = qce_crypto_remove,
        .driver = {
                .name = KBUILD_MODNAME,
                .of_match_table = qce_crypto_of_match,
        },
};
module_platform_driver(qce_crypto_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Qualcomm crypto engine driver");
MODULE_ALIAS("platform:" KBUILD_MODNAME);
MODULE_AUTHOR("The Linux Foundation");