/*
 * The driver of sunxi emce.
 *
 * Copyright (C) 2016 Allwinner.
 *
 * zhouhuacai <zhouhuacai@allwinnertech.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <linux/clk.h>
#include <linux/clk/sunxi.h>
#include <linux/dma-mapping.h>
#include <crypto/hash.h>
#include <linux/delay.h>
#include "sunxi_emce.h"

#ifdef CONFIG_OF
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>

static const struct of_device_id sunxi_emce_of_match[] = {
	{.compatible = "allwinner,sunxi-emce",},
	{},
};

MODULE_DEVICE_TABLE(of, sunxi_emce_of_match);
#endif

#define STORAGE_NAND 0
#define STORAGE_EMMC 2

static int boot_type_cmdline = -1;
struct sunxi_emce_t *emce_dev;
struct task_des *task_des_buf;
dma_addr_t task_des_addr;

static unsigned int boot_type_parse(char *boot_type)
{
	long int ret;
	int tmp;

	tmp = kstrtol(boot_type, 0, &ret);
	if (ret == STORAGE_NAND)
		return 0;
	if (ret == STORAGE_EMMC)
		return 1;
	return -1;
}

static int __init early_boot_type(char *boot_type)
{
	pr_debug("%s(%s)\n", __func__, boot_type);
	boot_type_cmdline = boot_type_parse(boot_type);
	return 0;
}
early_param("boot_type", early_boot_type);

void sunxi_emce_dump(void *addr, u32 size)
{
	int i;

	pr_cont("=========dump:size:0x%x=========\n", size);
	for (i = 0; i < size; i += 4) {
		if (!(i&0xf))
			pr_cont("\n0x%p : ", (addr + i));
		pr_cont("%08x ", readl(addr + i));
	}
	pr_cont("\n");
}

static DEFINE_MUTEX(emce_lock);

static void emce_dev_lock(void)
{
	mutex_lock(&emce_lock);
}

static void emce_dev_unlock(void)
{
	mutex_unlock(&emce_lock);
}

static int sunxi_emce_gen_salt(const u8 *mkey,
			u32 mklen, u8 *skey, u32 *sklen)
{
	int ret = 0;
	struct scatterlist sg = {0};
	struct crypto_ahash *tfm = NULL;
	struct ahash_request *req = NULL;

	EMCE_ENTER();
	tfm = crypto_alloc_ahash("sha256", CRYPTO_ALG_TYPE_AHASH, CRYPTO_ALG_TYPE_AHASH_MASK);
	if (IS_ERR(tfm)) {
		ret = PTR_ERR(tfm);
		EMCE_ERR("Failed to alloc sha256 tfm. %p\n", tfm);
		goto out2;
	}

	req = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!req)
		EMCE_ERR("Failed to alloc ahash request!\n");

	ahash_request_set_callback(req, 0, NULL, NULL);

	sg_init_one(&sg, mkey, mklen);
	ahash_request_set_crypt(req, &sg, skey, mklen);
	ret = crypto_ahash_digest(req);
	if (ret) {
		EMCE_ERR("Failed to do SHA256(), mklen: %d\n", mklen);
		goto out1;
	}
	*sklen = EMCE_SALT_KEY_LEN;

out1:
	ahash_request_free(req);
	crypto_free_ahash(tfm);
out2:
	return ret;
}

static inline void sunxi_emce_set_bit(void __iomem *reg_addr,
				u32 mask, u32 bit, u32 val)
{
	u32 reg_val = 0;

	reg_val = readl(reg_addr);
	reg_val &= (~mask);
	reg_val |= (val << bit);
	writel(reg_val, reg_addr);
}

static inline u32 sunxi_emce_get_bit(void __iomem *reg_addr, u32 mask, u32 bit)
{
	u32 reg_val = 0;

	reg_val = readl(reg_addr);
	reg_val &= mask;

	return reg_val >> bit;
}

static void emce_get_key_len(u32 key1_len, u32 key2_len,
		struct sunxi_emce_regs *reg)
{

	if (reg) {
		switch (key1_len) {
		case 128:
			reg->key1_len = EMCE_KEY_128_BIT;
			break;
		case 192:
			reg->key1_len = EMCE_KEY_192_BIT;
			break;
		case 256:
			reg->key1_len = EMCE_KEY_256_BIT;
			break;
		default:
			break;
		}

		switch (key2_len) {
		case 128:
			reg->key2_len = EMCE_KEY_128_BIT;
			break;
		case 192:
			reg->key2_len = EMCE_KEY_192_BIT;
			break;
		case 256:
			reg->key2_len = EMCE_KEY_256_BIT;
			break;
		default:
			break;
		}
	}
}

static int sunxi_emce_set_cfg(enum cfg_cmd cmd, u32 para)
{
	int ret = 0;
	void __iomem *reg_addr = emce_dev->base_addr + EMCE_MODE;

	EMCE_ENTER();
	emce_dev_lock();
	switch (cmd) {
	case EMCE_SET_SECTOR_SIZE:
		sunxi_emce_set_bit(reg_addr, EMCE_SECTOR_SIZE_MASK,
				EMCE_SECTOR_SIZE_BIT, para);
		break;
	case EMCE_SET_IV_LEN:
		sunxi_emce_set_bit(reg_addr, EMCE_IV_LEN_MASK,
				EMCE_IV_LEN_BIT, para);
		break;
	case EMCE_SET_KEY_LEN:
		sunxi_emce_set_bit(reg_addr, EMCE_KEY_LEN_MASK,
				EMCE_KEY_LEN_BIT, para);
		break;
	case EMCE_SET_MODE:
		sunxi_emce_set_bit(reg_addr, EMCE_MODE_MASK,
				EMCE_MODE_BIT, para);
		break;
	default:
		EMCE_ERR("Unsupport cmd %d\n", cmd);
		break;
	}
	emce_dev_unlock();

	return ret;
}

void sunxi_emce_set_mode(u32 para)
{
	if (emce_dev->emce_vision == EMCE_VISION_1)
		sunxi_emce_set_cfg(EMCE_SET_MODE, para);
	else
		emce_dev->regs.crypto_mode = para;
}
EXPORT_SYMBOL_GPL(sunxi_emce_set_mode);

void sunxi_emce_set_task_des(int data_len, int bypass)
{
	struct sunxi_emce_regs *reg = &emce_dev->regs;
	int i;

	if (emce_dev->emce_vision == EMCE_VISION_1)
		return;
	sunxi_emce_set_mode(0x1);
	task_des_buf->com_ctrl =
		(reg->key2_len << 12) | (reg->key1_len << 8) |
			(reg->crypto_mode << 4) | bypass;
	task_des_buf->data_len = data_len / 4;
	for (i = 0; i < 8; i++) {
		task_des_buf->key1[i] = reg->emce_key[i];
		task_des_buf->key2[i] = reg->emce_salt[i];
	}
	task_des_buf->next_task = 0x0;
	emce_writel(emce_dev, EMCE_TASK_DES_ADD, (u32)(task_des_addr));
	udelay(10);

}
EXPORT_SYMBOL_GPL(sunxi_emce_set_task_des);

void sunxi_emce_set_task_load(int para)
{
	if (emce_dev->emce_vision == EMCE_VISION_1)
		return;
	emce_writel(emce_dev, EMCE_TASK_LOAD, para);
}
EXPORT_SYMBOL_GPL(sunxi_emce_set_task_load);

void sunxi_emce_set_sector_size(u32 para)
{
	sunxi_emce_set_cfg(EMCE_SET_SECTOR_SIZE, para);
}
EXPORT_SYMBOL_GPL(sunxi_emce_set_sector_size);

void sunxi_emce_set_key_len(u32 para)
{
	sunxi_emce_set_cfg(EMCE_SET_KEY_LEN, para);
	sunxi_emce_set_cfg(EMCE_SET_IV_LEN, para);
}

static void sunxi_emce_set_cur_controller(struct sunxi_emce_t *emce_pdev, u32 para)
{
	void __iomem *reg_addr = emce_pdev->base_addr + EMCE_MODE;

	sunxi_emce_set_bit(reg_addr, EMCE_CUR_CTR_MASK, EMCE_CUR_CTR_BIT, para);
}

static void sunxi_emce_set_masterkey(const u8 *mkey, u32 klen)
{
	int i = 0;
	void __iomem *reg_addr = emce_dev->base_addr + EMCE_MASTER_KEY_OFFSET;

	if ((mkey == NULL) || (klen <= 0))
		EMCE_ERR("sunxi emce masterkey error\n ");

	for (i = 0; i < klen; i = i + 4)
		writel(*(u32 *)(mkey + i), (reg_addr + i));
}

static void sunxi_emce_set_saltkey(const u8 *skey, u32 klen)
{
	int i = 0;
	void __iomem *reg_addr = emce_dev->base_addr + EMCE_SALT_KEY_OFFSET;

	if ((skey == NULL) || (klen <= 0))
		EMCE_ERR("sunxi emce saltkey error\n ");

	for (i = 0; i < klen; i = i + 4)
		writel((*(u32 *)(skey + i)), reg_addr + i);
}

int sunxi_emce_set_key(const u8 *mkey, u32 len)
{
	u8 saltkey[EMCE_SALT_KEY_LEN];
	u32 skey_len = 0;
	struct sunxi_emce_regs *reg = &emce_dev->regs;
	int ret = 0;
	int i;

	EMCE_ENTER();
	if ((mkey == NULL) || (len <= 0))
		EMCE_ERR("sunxi emce key error\n ");


	if (emce_dev->emce_vision == EMCE_VISION_1) {
		ret = sunxi_emce_gen_salt(mkey, len, saltkey, &skey_len);
		if (!ret) {
			sunxi_emce_set_saltkey(saltkey, skey_len);
			sunxi_emce_set_masterkey(mkey, len);
		}

	} else {
		ret = sunxi_emce_gen_salt(mkey, len, saltkey, &skey_len);
		if (!ret) {
			for (i = 0; i < len; i = i + 4)
				reg->emce_key[(i >> 2)] = *(u32 *)(mkey + i);
			for (i = 0; i < skey_len; i = i + 4)
				reg->emce_salt[(i >> 2)] = *(u32 *)(saltkey + i);
		}
		emce_get_key_len(len, skey_len, reg);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(sunxi_emce_set_key);

static int sunxi_emce_get_version(void)
{
	emce_dev->emce_vision = readl(emce_dev->base_addr + EMCE_VER);
	pr_info("[EMCE]:VER:0x%x\n", emce_dev->emce_vision);
	return emce_dev->emce_vision;
}

static void sunxi_emce_show_cur_controller(u32 cur_controller)
{
	if (cur_controller)
		pr_info("[EMCE]:Current Controller is EMMC!\n");
	else
		pr_info("[EMCE]:Current Controller is NAND!\n");
}

static int sunxi_emce_hw_init(struct sunxi_emce_t *emce)
{
	struct device_node *pnode = emce->pdev->dev.of_node;
	struct clk *pclk = NULL;
	int ret = 0;

#if (defined CONFIG_FPGA_V4_PLATFORM) | (defined CONFIG_FPGA_V7_PLATFORM)
	emce->mclk = of_clk_get(pnode, 0);
	if (IS_ERR_OR_NULL(emce->mclk)) {
		EMCE_ERR("Unable to get mclk, return %x\n",
				PTR_RET(emce->mclk));
		return PTR_RET(emce->mclk);
	}
#else
	pclk = of_clk_get(pnode, 1);
	if (IS_ERR_OR_NULL(pclk)) {
		EMCE_ERR("Unable to get pclk, return %x\n", PTR_RET(pclk));
		return PTR_RET(pclk);
	}

	emce->mclk = of_clk_get(pnode, 0);
	if (IS_ERR_OR_NULL(emce->mclk)) {
		EMCE_ERR("Unable to get mclk, return %x\n",
				PTR_RET(emce->mclk));
		return PTR_RET(emce->mclk);
	}

	if (of_property_read_u32(pnode, "clock-frequency",
				&emce->gen_clkrate)) {
		EMCE_ERR("Unable to get clock-frequency.\n");
		return -EINVAL;
	}

	ret = clk_set_parent(emce->mclk, pclk);
	if (ret) {
		EMCE_ERR("clk_set_parent() failed! return %d\n", ret);
		return ret;
	}

	ret = clk_set_rate(emce->mclk, emce->gen_clkrate);
	if (ret) {
		EMCE_ERR("clk_set_rate(%d) failed! return %d\n",
				emce->gen_clkrate, ret);
		return ret;
	}

	EMCE_DBG("[EMCE]: mclk %luMHz, pclk %luMHz\n",
			clk_get_rate(emce->mclk)/1000000,
			clk_get_rate(pclk)/1000000);
#endif
	if (clk_prepare_enable(emce->mclk)) {
		EMCE_ERR("Couldn't enable module clock\n");
		return -EBUSY;
	}


	/*just for fpga*/
#if (defined CONFIG_FPGA_V4_PLATFORM) | (defined CONFIG_FPGA_V7_PLATFORM)
	void __iomem *ccmu_gat_reg = NULL;
	ccmu_gat_reg = ioremap(0x3001804, 0x1);
	writel((readl(ccmu_gat_reg) | (0x1 << 24)), ccmu_gat_reg);
	pr_info("[EMCE] ccmu mask gating %08x\n", readl(ccmu_gat_reg));
#endif
	if (boot_type_cmdline != -1) {
		sunxi_emce_set_cur_controller(emce, boot_type_cmdline);
		sunxi_emce_show_cur_controller(boot_type_cmdline);
	} else {
		pr_info("[EMCE]:Unsupport Current Storage!\n");
		return -EINVAL;
	}
	clk_put(pclk);

	return ret;
}

static int sunxi_emce_hw_exit(struct sunxi_emce_t *emce)
{
	EMCE_EXIT();
	clk_disable_unprepare(emce->mclk);
	clk_put(emce->mclk);
	emce->mclk = NULL;

	return 0;
}

static int sunxi_emce_res_request(struct platform_device *pdev)
{
	struct device_node *np = NULL;
	struct sunxi_emce_t *emce = platform_get_drvdata(pdev);

	np = pdev->dev.of_node;
	if (!of_device_is_available(np)) {
		EMCE_ERR("sunxi emce is disable\n");
		return -EPERM;
	}
	emce->base_addr = of_iomap(np, 0);
	if (emce->base_addr != 0)
		EMCE_DBG("sunxi emce reg base: %p !\n", emce->base_addr);
	else {
		EMCE_ERR("Failed to ioremap() io memory region.\n");
		return -EBUSY;
	}

	return 0;
}
static int sunxi_emce_res_release(struct sunxi_emce_t *emce)
{
	iounmap(emce->base_addr);
	return 0;
}

static void emce_get_cur_ctl_str(struct sunxi_emce_t *emce, char *str)
{
	if (str == NULL)
		return;

	if (!sunxi_emce_get_bit(emce->base_addr + EMCE_MODE,
			EMCE_CUR_CTR_MASK, EMCE_CUR_CTR_BIT))
		sprintf(str, "%s", "NDFC");
	else
		sprintf(str, "%s", "SMHC");
}

static void emce_get_key_len_str(u32 val, char *str)
{
	if (str == NULL)
		return;
	if (emce_dev->emce_vision == EMCE_VISION_1) {
		switch (val) {
		case EMCE_KEY_128_BIT:
			sprintf(str, "%s", "128bit");
			break;
		case EMCE_KEY_192_BIT:
			sprintf(str, "%s", "192bit");
			break;
		case EMCE_KEY_256_BIT:
			sprintf(str, "%s", "256bit");
			break;
		default:
			sprintf(str, "%s", "reserved");
			break;
		}
	}
}

static void emce_get_mode(struct sunxi_emce_t *emce, char *str)
{
	if (str == NULL)
		return;
	if (emce_dev->emce_vision == EMCE_VISION_1) {
		if (!sunxi_emce_get_bit(emce->base_addr + EMCE_MODE,
			EMCE_MODE_MASK, EMCE_MODE_BIT))
			sprintf(str, "%s", "ECB");
		else
			sprintf(str, "%s", "CBC");
	}
}

static ssize_t sunxi_emce_info_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	u32 iv_len;
	u32 key_len;
	char cur_ctl_str[MAXNAME];
	char iv_len_str[MAXNAME];
	char key_len_str[MAXNAME];
	char mode_str[MAXNAME];
	struct platform_device *pdev;
	struct sunxi_emce_t *emce;

	pdev = container_of(dev, struct platform_device, dev);
	emce = platform_get_drvdata(pdev);
	iv_len = sunxi_emce_get_bit(emce->base_addr + EMCE_MODE,
				EMCE_IV_LEN_MASK, EMCE_IV_LEN_BIT),
	key_len = sunxi_emce_get_bit(emce->base_addr + EMCE_MODE,
				EMCE_KEY_LEN_MASK, EMCE_KEY_LEN_BIT),

	emce_get_cur_ctl_str(emce, cur_ctl_str);
	emce_get_mode(emce, mode_str);
	emce_get_key_len_str(iv_len, iv_len_str);
	emce_get_key_len_str(key_len, key_len_str);

	return snprintf(buf, PAGE_SIZE,
		"pdev->id   = %d\n"
		"pdev->name = %s\n"
		"module clk rate = %ld Mhz\n"
		"IO membase = 0x%p\n"
		"sector size = 0x%x\n"
		"cur controller = %s\n"
		"AES IV len = %s\n"
		"key len = %s\n"
		"mode = %s\n"
		"emce version = 0x%x\n",
		pdev->id, pdev->name,
		(clk_get_rate(emce->mclk)/1000000), emce->base_addr,
		sunxi_emce_get_bit(emce->base_addr + EMCE_MODE,
				EMCE_SECTOR_SIZE_MASK, EMCE_SECTOR_SIZE_BIT),
		cur_ctl_str, iv_len_str, key_len_str, mode_str,
		readl(emce->base_addr + EMCE_VER));
}

static struct device_attribute sunxi_emce_info_attr =
	__ATTR(info, S_IRUGO, sunxi_emce_info_show, NULL);

static int sunxi_emce_sysfs_create(struct platform_device *_pdev)
{
	int ret;

	ret = device_create_file(&_pdev->dev, &sunxi_emce_info_attr);
	return ret;
}

static void sunxi_emce_sysfs_remove(struct platform_device *_pdev)
{
	device_remove_file(&_pdev->dev, &sunxi_emce_info_attr);
}

static int sunxi_emce_probe(struct platform_device *pdev)
{
	u32 ret = 0;
	struct sunxi_emce_t *emce = NULL;

	emce = devm_kzalloc(&pdev->dev, sizeof(struct sunxi_emce_t), GFP_KERNEL);
	if (emce == NULL) {
		EMCE_ERR("Unable to allocate emce_data\n");
		return -ENOMEM;
	}
	snprintf(emce->dev_name, sizeof(emce->dev_name), SUNXI_EMCE_DEV_NAME);
	platform_set_drvdata(pdev, emce);

	ret = sunxi_emce_res_request(pdev);
	if (ret != 0)
		goto err0;

	emce->pdev = pdev;

	ret = sunxi_emce_hw_init(emce);
	if (ret != 0) {
		EMCE_ERR("emce hw init failed!\n");
		goto err1;
	}
	emce_dev = emce;

	ret = sunxi_emce_get_version();
	if (!ret) {
		EMCE_ERR("sunxi emce version error\n");
		ret = -ENXIO;
		goto err1;
	}

	task_des_buf = dma_alloc_coherent(&pdev->dev, PAGE_SIZE, &task_des_addr, GFP_KERNEL);
	if (!task_des_buf) {
		EMCE_ERR("%s: Counld not allocate buffer\n", __func__);
		ret = -ENOMEM;
		goto err1;
	}

	ret = sunxi_emce_sysfs_create(pdev);
	if (ret) {
		EMCE_ERR("%s:create sys fs failed\n", __func__);
		goto err_free_buf;
	}

	return 0;

err_free_buf:
	dma_free_coherent(&pdev->dev, PAGE_SIZE, task_des_buf, task_des_addr);
err1:
	sunxi_emce_res_release(emce);
err0:
	platform_set_drvdata(pdev, NULL);

	return ret;
}

static int sunxi_emce_remove(struct platform_device *pdev)
{
	struct sunxi_emce_t *emce = platform_get_drvdata(pdev);

	sunxi_emce_sysfs_remove(pdev);
	sunxi_emce_hw_exit(emce);
	dma_free_coherent(&pdev->dev, PAGE_SIZE, task_des_buf, task_des_addr);
	sunxi_emce_res_release(emce);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static void sunxi_emce_regs_save(struct sunxi_emce_t *emce)
{
	int i;
	struct sunxi_emce_regs *regs = &emce->regs;

	if (emce_dev->emce_vision == EMCE_VISION_1) {
		for (i = 0; i < 8; i++) {
			regs->emce_key[i] =
				emce_readl(emce, (EMCE_MASTER_KEY_OFFSET + 4 * i));
			regs->emce_salt[i] =
				emce_readl(emce, (EMCE_SALT_KEY_OFFSET + 4 * i));
		}
	}
	regs->emce_mode = emce_readl(emce, EMCE_MODE);

}

static void sunxi_emce_regs_restore(struct sunxi_emce_t *emce)
{
	int i;
	struct sunxi_emce_regs *regs = &emce->regs;

	if (emce_dev->emce_vision == EMCE_VISION_1) {
		for (i = 0; i < 8; i++) {
			emce_writel(emce, (EMCE_MASTER_KEY_OFFSET + 4 * i),
				    regs->emce_key[i]);
			emce_writel(emce, (EMCE_SALT_KEY_OFFSET + 4 * i),
				    regs->emce_salt[i]);
		}
	}
	emce_writel(emce, EMCE_MODE, regs->emce_mode);

}
#ifdef CONFIG_PM
static int sunxi_emce_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct sunxi_emce_t *emce = platform_get_drvdata(pdev);

	pr_info("[EMCE]:suspend enter...\n");
	sunxi_emce_regs_save(emce);
	sunxi_emce_hw_exit(emce);

	return 0;
}

static int sunxi_emce_resume(struct device *dev)
{
	int ret = 0;
	struct platform_device *pdev = to_platform_device(dev);
	struct sunxi_emce_t *emce = platform_get_drvdata(pdev);

	pr_info("[EMCE]:resume enter...\n");
	ret = sunxi_emce_hw_init(emce);
	sunxi_emce_regs_restore(emce);

	return ret;
}

static const struct dev_pm_ops sunxi_emce_dev_pm_ops = {
	.suspend = sunxi_emce_suspend,
	.resume  = sunxi_emce_resume,
};

#define SUNXI_EMCE_DEV_PM_OPS (&sunxi_emce_dev_pm_ops)
#else
#define SUNXI_EMCE_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

static struct platform_driver sunxi_emce_driver = {
	.probe   = sunxi_emce_probe,
	.remove  = sunxi_emce_remove,
	.driver = {
		.name	= SUNXI_EMCE_DEV_NAME,
		.owner	= THIS_MODULE,
		.pm		= SUNXI_EMCE_DEV_PM_OPS,
		.of_match_table = sunxi_emce_of_match,
	},
};

static int __init sunxi_emce_init(void)
{
	int ret = 0;

	EMCE_DBG("Sunxi EMCE init ...\n");
	ret = platform_driver_register(&sunxi_emce_driver);
	if (ret < 0)
		EMCE_ERR("platform_driver_register() failed, return %d\n", ret);

	return ret;
}

static void __exit sunxi_emce_exit(void)
{
	platform_driver_unregister(&sunxi_emce_driver);
}

module_init(sunxi_emce_init);
module_exit(sunxi_emce_exit);

MODULE_AUTHOR("zhouhuacai");
MODULE_DESCRIPTION("SUNXI EMCE Driver");
MODULE_ALIAS("platform:"SUNXI_EMCE_DEV_NAME);
MODULE_LICENSE("GPL");