/* SPDX-License-Identifier: GPL-2.0 */
/*
 * amlogic.h - hardware cryptographic offloader for Amlogic SoC
 *
 * Copyright (C) 2018-2019 Corentin LABBE <clabbe@baylibre.com>
 */
#include <crypto/aes.h>
#include <crypto/engine.h>
#include <crypto/skcipher.h>
#include <linux/debugfs.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>

#define MODE_KEY 1
#define MODE_AES_128 0x8
#define MODE_AES_192 0x9
#define MODE_AES_256 0xa

#define MESON_DECRYPT 0
#define MESON_ENCRYPT 1

#define MESON_OPMODE_ECB 0
#define MESON_OPMODE_CBC 1

#define MAXFLOW 2

#define MAXDESC 64

#define DESC_LAST BIT(18)
#define DESC_ENCRYPTION BIT(28)
#define DESC_OWN BIT(31)

/*
 * struct meson_desc - Descriptor for DMA operations
 * Note that without datasheet, some are unknown
 * @t_status:   Descriptor of the cipher operation (see description below)
 * @t_src:      Physical address of data to read
 * @t_dst:      Physical address of data to write
 * t_status is segmented like this:
 * @len:        0-16    length of data to operate
 * @irq:        17      Ignored by hardware
 * @eoc:        18      End means the descriptor is the last
 * @loop:       19      Unknown
 * @mode:       20-23   Type of algorithm (AES, SHA)
 * @begin:      24      Unknown
 * @end:        25      Unknown
 * @op_mode:    26-27   Blockmode (CBC, ECB)
 * @enc:        28      0 means decryption, 1 is for encryption
 * @block:      29      Unknown
 * @error:      30      Unknown
 * @owner:      31      owner of the descriptor, 1 own by HW
 */
struct meson_desc {
        __le32 t_status;
        __le32 t_src;
        __le32 t_dst;
};

/*
 * struct meson_flow - Information used by each flow
 * @engine:     ptr to the crypto_engine for this flow
 * @keylen:     keylen for this flow operation
 * @complete:   completion for the current task on this flow
 * @status:     set to 1 by interrupt if task is done
 * @t_phy:      Physical address of task
 * @tl:         pointer to the current ce_task for this flow
 * @stat_req:   number of request done by this flow
 */
struct meson_flow {
        struct crypto_engine *engine;
        struct completion complete;
        int status;
        unsigned int keylen;
        dma_addr_t t_phy;
        struct meson_desc *tl;
#ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
        unsigned long stat_req;
#endif
};

/*
 * struct meson_dev - main container for all this driver information
 * @base:       base address of amlogic-crypto
 * @busclk:     bus clock for amlogic-crypto
 * @dev:        the platform device
 * @chanlist:   array of all flow
 * @flow:       flow to use in next request
 * @irqs:       IRQ numbers for amlogic-crypto
 * @dbgfs_dir:  Debugfs dentry for statistic directory
 * @dbgfs_stats: Debugfs dentry for statistic counters
 */
struct meson_dev {
        void __iomem *base;
        struct clk *busclk;
        struct device *dev;
        struct meson_flow *chanlist;
        atomic_t flow;
        int irqs[MAXFLOW];
#ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
        struct dentry *dbgfs_dir;
#endif
};

/*
 * struct meson_cipher_req_ctx - context for a skcipher request
 * @op_dir:     direction (encrypt vs decrypt) for this request
 * @flow:       the flow to use for this request
 */
struct meson_cipher_req_ctx {
        u32 op_dir;
        int flow;
        struct skcipher_request fallback_req;   // keep at the end
};

/*
 * struct meson_cipher_tfm_ctx - context for a skcipher TFM
 * @key:                pointer to key data
 * @keylen:             len of the key
 * @keymode:            The keymode(type and size of key) associated with this TFM
 * @mc:                 pointer to the private data of driver handling this TFM
 * @fallback_tfm:       pointer to the fallback TFM
 */
struct meson_cipher_tfm_ctx {
        u32 *key;
        u32 keylen;
        u32 keymode;
        struct meson_dev *mc;
        struct crypto_skcipher *fallback_tfm;
};

/*
 * struct meson_alg_template - crypto_alg template
 * @type:               the CRYPTO_ALG_TYPE for this template
 * @blockmode:          the type of block operation
 * @mc:                 pointer to the meson_dev structure associated with this template
 * @alg:                one of sub struct must be used
 * @stat_req:           number of request done on this template
 * @stat_fb:            total of all data len done on this template
 */
struct meson_alg_template {
        u32 type;
        u32 blockmode;
        union {
                struct skcipher_engine_alg skcipher;
        } alg;
        struct meson_dev *mc;
#ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
        unsigned long stat_req;
        unsigned long stat_fb;
#endif
};

int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
                     unsigned int keylen);
int meson_cipher_init(struct crypto_tfm *tfm);
void meson_cipher_exit(struct crypto_tfm *tfm);
int meson_skdecrypt(struct skcipher_request *areq);
int meson_skencrypt(struct skcipher_request *areq);
int meson_handle_cipher_request(struct crypto_engine *engine, void *areq);