/*
 * Crypto acceleration support for Rockchip RK3288
 *
 * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
 *
 * Author: Zain Wang <zain.wang@rock-chips.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * Some ideas are from marvell-cesa.c and s5p-sss.c driver.
 */

#include "rk3288_crypto.h"
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/clk.h>
#include <linux/crypto.h>
#include <linux/reset.h>

static int rk_crypto_enable_clk(struct rk_crypto_info *dev)
{
	int err;

	err = clk_prepare_enable(dev->sclk);
	if (err) {
		dev_err(dev->dev, "[%s:%d], Couldn't enable clock sclk\n",
			__func__, __LINE__);
		goto err_return;
	}
	err = clk_prepare_enable(dev->aclk);
	if (err) {
		dev_err(dev->dev, "[%s:%d], Couldn't enable clock aclk\n",
			__func__, __LINE__);
		goto err_aclk;
	}
	err = clk_prepare_enable(dev->hclk);
	if (err) {
		dev_err(dev->dev, "[%s:%d], Couldn't enable clock hclk\n",
			__func__, __LINE__);
		goto err_hclk;
	}
	err = clk_prepare_enable(dev->dmaclk);
	if (err) {
		dev_err(dev->dev, "[%s:%d], Couldn't enable clock dmaclk\n",
			__func__, __LINE__);
		goto err_dmaclk;
	}
	return err;
err_dmaclk:
	clk_disable_unprepare(dev->hclk);
err_hclk:
	clk_disable_unprepare(dev->aclk);
err_aclk:
	clk_disable_unprepare(dev->sclk);
err_return:
	return err;
}

static void rk_crypto_disable_clk(struct rk_crypto_info *dev)
{
	clk_disable_unprepare(dev->dmaclk);
	clk_disable_unprepare(dev->hclk);
	clk_disable_unprepare(dev->aclk);
	clk_disable_unprepare(dev->sclk);
}

static int check_alignment(struct scatterlist *sg_src,
			   struct scatterlist *sg_dst,
			   int align_mask)
{
	int in, out, align;

	in = IS_ALIGNED((uint32_t)sg_src->offset, 4) &&
	     IS_ALIGNED((uint32_t)sg_src->length, align_mask);
	if (!sg_dst)
		return in;
	out = IS_ALIGNED((uint32_t)sg_dst->offset, 4) &&
	      IS_ALIGNED((uint32_t)sg_dst->length, align_mask);
	align = in && out;

	return (align && (sg_src->length == sg_dst->length));
}

static int rk_load_data(struct rk_crypto_info *dev,
			struct scatterlist *sg_src,
			struct scatterlist *sg_dst)
{
	unsigned int count;

	dev->aligned = dev->aligned ?
		check_alignment(sg_src, sg_dst, dev->align_size) :
		dev->aligned;
	if (dev->aligned) {
		count = min(dev->left_bytes, sg_src->length);
		dev->left_bytes -= count;

		if (!dma_map_sg(dev->dev, sg_src, 1, DMA_TO_DEVICE)) {
			dev_err(dev->dev, "[%s:%d] dma_map_sg(src)  error\n",
				__func__, __LINE__);
			return -EINVAL;
		}
		dev->addr_in = sg_dma_address(sg_src);

		if (sg_dst) {
			if (!dma_map_sg(dev->dev, sg_dst, 1, DMA_FROM_DEVICE)) {
				dev_err(dev->dev,
					"[%s:%d] dma_map_sg(dst)  error\n",
					__func__, __LINE__);
				dma_unmap_sg(dev->dev, sg_src, 1,
					     DMA_TO_DEVICE);
				return -EINVAL;
			}
			dev->addr_out = sg_dma_address(sg_dst);
		}
	} else {
		count = (dev->left_bytes > PAGE_SIZE) ?
			PAGE_SIZE : dev->left_bytes;

		if (!sg_pcopy_to_buffer(dev->first, dev->nents,
					dev->addr_vir, count,
					dev->total - dev->left_bytes)) {
			dev_err(dev->dev, "[%s:%d] pcopy err\n",
				__func__, __LINE__);
			return -EINVAL;
		}
		dev->left_bytes -= count;
		sg_init_one(&dev->sg_tmp, dev->addr_vir, count);
		if (!dma_map_sg(dev->dev, &dev->sg_tmp, 1, DMA_TO_DEVICE)) {
			dev_err(dev->dev, "[%s:%d] dma_map_sg(sg_tmp)  error\n",
				__func__, __LINE__);
			return -ENOMEM;
		}
		dev->addr_in = sg_dma_address(&dev->sg_tmp);

		if (sg_dst) {
			if (!dma_map_sg(dev->dev, &dev->sg_tmp, 1,
					DMA_FROM_DEVICE)) {
				dev_err(dev->dev,
					"[%s:%d] dma_map_sg(sg_tmp)  error\n",
					__func__, __LINE__);
				dma_unmap_sg(dev->dev, &dev->sg_tmp, 1,
					     DMA_TO_DEVICE);
				return -ENOMEM;
			}
			dev->addr_out = sg_dma_address(&dev->sg_tmp);
		}
	}
	dev->count = count;
	return 0;
}

static void rk_unload_data(struct rk_crypto_info *dev)
{
	struct scatterlist *sg_in, *sg_out;

	sg_in = dev->aligned ? dev->sg_src : &dev->sg_tmp;
	dma_unmap_sg(dev->dev, sg_in, 1, DMA_TO_DEVICE);

	if (dev->sg_dst) {
		sg_out = dev->aligned ? dev->sg_dst : &dev->sg_tmp;
		dma_unmap_sg(dev->dev, sg_out, 1, DMA_FROM_DEVICE);
	}
}

static irqreturn_t rk_crypto_irq_handle(int irq, void *dev_id)
{
	struct rk_crypto_info *dev  = platform_get_drvdata(dev_id);
	u32 interrupt_status;
	int err = 0;

	spin_lock(&dev->lock);
	interrupt_status = CRYPTO_READ(dev, RK_CRYPTO_INTSTS);
	CRYPTO_WRITE(dev, RK_CRYPTO_INTSTS, interrupt_status);
	if (interrupt_status & 0x0a) {
		dev_warn(dev->dev, "DMA Error\n");
		err = -EFAULT;
	} else if (interrupt_status & 0x05) {
		err = dev->update(dev);
	}
	if (err)
		dev->complete(dev, err);
	spin_unlock(&dev->lock);
	return IRQ_HANDLED;
}

static void rk_crypto_tasklet_cb(unsigned long data)
{
	struct rk_crypto_info *dev = (struct rk_crypto_info *)data;
	struct crypto_async_request *async_req, *backlog;
	unsigned long flags;
	int err = 0;

	spin_lock_irqsave(&dev->lock, flags);
	backlog   = crypto_get_backlog(&dev->queue);
	async_req = crypto_dequeue_request(&dev->queue);
	spin_unlock_irqrestore(&dev->lock, flags);
	if (!async_req) {
		dev_err(dev->dev, "async_req is NULL !!\n");
		return;
	}
	if (backlog) {
		backlog->complete(backlog, -EINPROGRESS);
		backlog = NULL;
	}

	if (crypto_tfm_alg_type(async_req->tfm) == CRYPTO_ALG_TYPE_ABLKCIPHER)
		dev->ablk_req = ablkcipher_request_cast(async_req);
	err = dev->start(dev);
	if (err)
		dev->complete(dev, err);
}

static struct rk_crypto_tmp *rk_cipher_algs[] = {
	&rk_ecb_aes_alg,
	&rk_cbc_aes_alg,
	&rk_ecb_des_alg,
	&rk_cbc_des_alg,
	&rk_ecb_des3_ede_alg,
	&rk_cbc_des3_ede_alg,
};

static int rk_crypto_register(struct rk_crypto_info *crypto_info)
{
	unsigned int i, k;
	int err = 0;

	for (i = 0; i < ARRAY_SIZE(rk_cipher_algs); i++) {
		rk_cipher_algs[i]->dev = crypto_info;
		err = crypto_register_alg(&rk_cipher_algs[i]->alg);
		if (err)
			goto err_cipher_algs;
	}
	return 0;

err_cipher_algs:
	for (k = 0; k < i; k++)
		crypto_unregister_alg(&rk_cipher_algs[k]->alg);
	return err;
}

static void rk_crypto_unregister(void)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(rk_cipher_algs); i++)
		crypto_unregister_alg(&rk_cipher_algs[i]->alg);
}

static void rk_crypto_action(void *data)
{
	struct rk_crypto_info *crypto_info = data;

	reset_control_assert(crypto_info->rst);
}

static const struct of_device_id crypto_of_id_table[] = {
	{ .compatible = "rockchip,rk3288-crypto" },
	{}
};
MODULE_DEVICE_TABLE(of, crypto_of_id_table);

static int rk_crypto_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct device *dev = &pdev->dev;
	struct rk_crypto_info *crypto_info;
	int err = 0;

	crypto_info = devm_kzalloc(&pdev->dev,
				   sizeof(*crypto_info), GFP_KERNEL);
	if (!crypto_info) {
		err = -ENOMEM;
		goto err_crypto;
	}

	crypto_info->rst = devm_reset_control_get(dev, "crypto-rst");
	if (IS_ERR(crypto_info->rst)) {
		err = PTR_ERR(crypto_info->rst);
		goto err_crypto;
	}

	reset_control_assert(crypto_info->rst);
	usleep_range(10, 20);
	reset_control_deassert(crypto_info->rst);

	err = devm_add_action(dev, rk_crypto_action, crypto_info);
	if (err) {
		reset_control_assert(crypto_info->rst);
		goto err_crypto;
	}

	spin_lock_init(&crypto_info->lock);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	crypto_info->reg = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(crypto_info->reg)) {
		err = PTR_ERR(crypto_info->reg);
		goto err_crypto;
	}

	crypto_info->aclk = devm_clk_get(&pdev->dev, "aclk");
	if (IS_ERR(crypto_info->aclk)) {
		err = PTR_ERR(crypto_info->aclk);
		goto err_crypto;
	}

	crypto_info->hclk = devm_clk_get(&pdev->dev, "hclk");
	if (IS_ERR(crypto_info->hclk)) {
		err = PTR_ERR(crypto_info->hclk);
		goto err_crypto;
	}

	crypto_info->sclk = devm_clk_get(&pdev->dev, "sclk");
	if (IS_ERR(crypto_info->sclk)) {
		err = PTR_ERR(crypto_info->sclk);
		goto err_crypto;
	}

	crypto_info->dmaclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(crypto_info->dmaclk)) {
		err = PTR_ERR(crypto_info->dmaclk);
		goto err_crypto;
	}

	crypto_info->irq = platform_get_irq(pdev, 0);
	if (crypto_info->irq < 0) {
		dev_warn(crypto_info->dev,
			 "control Interrupt is not available.\n");
		err = crypto_info->irq;
		goto err_crypto;
	}

	err = devm_request_irq(&pdev->dev, crypto_info->irq,
			       rk_crypto_irq_handle, IRQF_SHARED,
			       "rk-crypto", pdev);

	if (err) {
		dev_err(crypto_info->dev, "irq request failed.\n");
		goto err_crypto;
	}

	crypto_info->dev = &pdev->dev;
	platform_set_drvdata(pdev, crypto_info);

	tasklet_init(&crypto_info->crypto_tasklet,
		     rk_crypto_tasklet_cb, (unsigned long)crypto_info);
	crypto_init_queue(&crypto_info->queue, 50);

	crypto_info->enable_clk = rk_crypto_enable_clk;
	crypto_info->disable_clk = rk_crypto_disable_clk;
	crypto_info->load_data = rk_load_data;
	crypto_info->unload_data = rk_unload_data;

	err = rk_crypto_register(crypto_info);
	if (err) {
		dev_err(dev, "err in register alg");
		goto err_register_alg;
	}

	dev_info(dev, "Crypto Accelerator successfully registered\n");
	return 0;

err_register_alg:
	tasklet_kill(&crypto_info->crypto_tasklet);
err_crypto:
	return err;
}

static int rk_crypto_remove(struct platform_device *pdev)
{
	struct rk_crypto_info *crypto_tmp = platform_get_drvdata(pdev);

	rk_crypto_unregister();
	tasklet_kill(&crypto_tmp->crypto_tasklet);
	return 0;
}

static struct platform_driver crypto_driver = {
	.probe		= rk_crypto_probe,
	.remove		= rk_crypto_remove,
	.driver		= {
		.name	= "rk3288-crypto",
		.of_match_table	= crypto_of_id_table,
	},
};

module_platform_driver(crypto_driver);

MODULE_AUTHOR("Zain Wang <zain.wang@rock-chips.com>");
MODULE_DESCRIPTION("Support for Rockchip's cryptographic engine");
MODULE_LICENSE("GPL");