IRQ中斷以及tasklet的示例代碼

drivers/crypto/atmel-sha.c IRQ中斷以及tasklet的示例代碼

/*
 * Cryptographic API.
 *
 * Support for ATMEL SHA1/SHA256 HW acceleration.
 *
 * Copyright (c) 2012 Eukr茅a Electromatique - ATMEL
 * Author: Nicolas Royer <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * Some ideas are from omap-sham.c drivers.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/hw_random.h>
#include <linux/platform_device.h>

#include <linux/device.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/of_device.h>
#include <linux/delay.h>
#include <linux/crypto.h>
#include <linux/cryptohash.h>
#include <crypto/scatterwalk.h>
#include <crypto/algapi.h>
#include <crypto/sha.h>
#include <crypto/hash.h>
#include <crypto/internal/hash.h>
#include <linux/platform_data/crypto-atmel.h>
#include "atmel-sha-regs.h"

/* SHA flags */
#define SHA_FLAGS_BUSY          BIT(0)
#define SHA_FLAGS_FINAL         BIT(1)
#define SHA_FLAGS_DMA_ACTIVE    BIT(2)
#define SHA_FLAGS_OUTPUT_READY  BIT(3)
#define SHA_FLAGS_INIT          BIT(4)
#define SHA_FLAGS_CPU           BIT(5)
#define SHA_FLAGS_DMA_READY     BIT(6)

#define SHA_FLAGS_FINUP     BIT(16)
#define SHA_FLAGS_SG        BIT(17)
#define SHA_FLAGS_ALGO_MASK GENMASK(22, 18)
#define SHA_FLAGS_SHA1      BIT(18)
#define SHA_FLAGS_SHA224    BIT(19)
#define SHA_FLAGS_SHA256    BIT(20)
#define SHA_FLAGS_SHA384    BIT(21)
#define SHA_FLAGS_SHA512    BIT(22)
#define SHA_FLAGS_ERROR     BIT(23)
#define SHA_FLAGS_PAD       BIT(24)
#define SHA_FLAGS_RESTORE   BIT(25)

#define SHA_OP_UPDATE   1
#define SHA_OP_FINAL    2

#define SHA_BUFFER_LEN      (PAGE_SIZE / 16)

#define ATMEL_SHA_DMA_THRESHOLD     56

struct atmel_sha_caps {
    bool    has_dma;
    bool    has_dualbuff;
    bool    has_sha224;
    bool    has_sha_384_512;
    bool    has_uihv;
};

struct atmel_sha_dev;

/*
 * .statesize = sizeof(struct atmel_sha_reqctx) must be <= PAGE_SIZE / 8 as
 * tested by the ahash_prepare_alg() function.
 */
struct atmel_sha_reqctx {
    struct atmel_sha_dev    *dd;
    unsigned long   flags;
    unsigned long   op;

    u8  digest[SHA512_DIGEST_SIZE] __aligned(sizeof(u32));
    u64 digcnt[2];
    size_t  bufcnt;
    size_t  buflen;
    dma_addr_t  dma_addr;

    /* walk state */
    struct scatterlist  *sg;
    unsigned int    offset; /* offset in current sg */
    unsigned int    total;  /* total request */

    size_t block_size;

    u8 buffer[SHA_BUFFER_LEN + SHA512_BLOCK_SIZE] __aligned(sizeof(u32));
};

struct atmel_sha_ctx {
    struct atmel_sha_dev    *dd;

    unsigned long       flags;
};

#define ATMEL_SHA_QUEUE_LENGTH  50

struct atmel_sha_dma {
    struct dma_chan         *chan;
    struct dma_slave_config dma_conf;
};

struct atmel_sha_dev {
    struct list_head    list;
    unsigned long       phys_base;
    struct device       *dev;
    struct clk          *iclk;
    int                 irq;
    void __iomem        *io_base;

    spinlock_t      lock;
    int         err;
    struct tasklet_struct   done_task;
    struct tasklet_struct   queue_task;

    unsigned long       flags;
    struct crypto_queue queue;
    struct ahash_request    *req;

    struct atmel_sha_dma    dma_lch_in;

    struct atmel_sha_caps   caps;

    u32 hw_version;
};

struct atmel_sha_drv {
    struct list_head    dev_list;
    spinlock_t      lock;
};

static struct atmel_sha_drv atmel_sha = {
    .dev_list = LIST_HEAD_INIT(atmel_sha.dev_list),
    .lock = __SPIN_LOCK_UNLOCKED(atmel_sha.lock),
};

static inline u32 atmel_sha_read(struct atmel_sha_dev *dd, u32 offset)
{
    return readl_relaxed(dd->io_base + offset);
}

static inline void atmel_sha_write(struct atmel_sha_dev *dd,
                    u32 offset, u32 value)
{
    writel_relaxed(value, dd->io_base + offset);
}

static size_t atmel_sha_append_sg(struct atmel_sha_reqctx *ctx)
{
    size_t count;

    while ((ctx->bufcnt < ctx->buflen) && ctx->total) {
        count = min(ctx->sg->length - ctx->offset, ctx->total);
        count = min(count, ctx->buflen - ctx->bufcnt);

        if (count <= 0) {
            /*
            * Check if count <= 0 because the buffer is full or
            * because the sg length is 0. In the latest case,
            * check if there is another sg in the list, a 0 length
            * sg doesn't necessarily mean the end of the sg list.
            */
            if ((ctx->sg->length == 0) && !sg_is_last(ctx->sg)) {
                ctx->sg = sg_next(ctx->sg);
                continue;
            } else {
                break;
            }
        }

        scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, ctx->sg,
            ctx->offset, count, 0);

        ctx->bufcnt += count;
        ctx->offset += count;
        ctx->total -= count;

        if (ctx->offset == ctx->sg->length) {
            ctx->sg = sg_next(ctx->sg);
            if (ctx->sg)
                ctx->offset = 0;
            else
                ctx->total = 0;
        }
    }

    return 0;
}

/*
 * The purpose of this padding is to ensure that the padded message is a
 * multiple of 512 bits (SHA1/SHA224/SHA256) or 1024 bits (SHA384/SHA512).
 * The bit "1" is appended at the end of the message followed by
 * "padlen-1" zero bits. Then a 64 bits block (SHA1/SHA224/SHA256) or
 * 128 bits block (SHA384/SHA512) equals to the message length in bits
 * is appended.
 *
 * For SHA1/SHA224/SHA256, padlen is calculated as followed:
 *  - if message length < 56 bytes then padlen = 56 - message length
 *  - else padlen = 64 + 56 - message length
 *
 * For SHA384/SHA512, padlen is calculated as followed:
 *  - if message length < 112 bytes then padlen = 112 - message length
 *  - else padlen = 128 + 112 - message length
 */
static void atmel_sha_fill_padding(struct atmel_sha_reqctx *ctx, int length)
{
    unsigned int index, padlen;
    u64 bits[2];
    u64 size[2];

    size[0] = ctx->digcnt[0];
    size[1] = ctx->digcnt[1];

    size[0] += ctx->bufcnt;
    if (size[0] < ctx->bufcnt)
        size[1]++;

    size[0] += length;
    if (size[0]  < length)
        size[1]++;

    bits[1] = cpu_to_be64(size[0] << 3);
    bits[0] = cpu_to_be64(size[1] << 3 | size[0] >> 61);

    if (ctx->flags & (SHA_FLAGS_SHA384 | SHA_FLAGS_SHA512)) {
        index = ctx->bufcnt & 0x7f;
        padlen = (index < 112) ? (112 - index) : ((128+112) - index);
        *(ctx->buffer + ctx->bufcnt) = 0x80;
        memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
        memcpy(ctx->buffer + ctx->bufcnt + padlen, bits, 16);
        ctx->bufcnt += padlen + 16;
        ctx->flags |= SHA_FLAGS_PAD;
    } else {
        index = ctx->bufcnt & 0x3f;
        padlen = (index < 56) ? (56 - index) : ((64+56) - index);
        *(ctx->buffer + ctx->bufcnt) = 0x80;
        memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
        memcpy(ctx->buffer + ctx->bufcnt + padlen, &bits[1], 8);
        ctx->bufcnt += padlen + 8;
        ctx->flags |= SHA_FLAGS_PAD;
    }
}

static int atmel_sha_init(struct ahash_request *req)
{
    struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
    struct atmel_sha_ctx *tctx = crypto_ahash_ctx(tfm);
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    struct atmel_sha_dev *dd = NULL;
    struct atmel_sha_dev *tmp;

    spin_lock_bh(&atmel_sha.lock);
    if (!tctx->dd) {
        list_for_each_entry(tmp, &atmel_sha.dev_list, list) {
            dd = tmp;
            break;
        }
        tctx->dd = dd;
    } else {
        dd = tctx->dd;
    }

    spin_unlock_bh(&atmel_sha.lock);

    ctx->dd = dd;

    ctx->flags = 0;

    dev_dbg(dd->dev, "init: digest size: %d\n",
        crypto_ahash_digestsize(tfm));

    switch (crypto_ahash_digestsize(tfm)) {
    case SHA1_DIGEST_SIZE:
        ctx->flags |= SHA_FLAGS_SHA1;
        ctx->block_size = SHA1_BLOCK_SIZE;
        break;
    case SHA224_DIGEST_SIZE:
        ctx->flags |= SHA_FLAGS_SHA224;
        ctx->block_size = SHA224_BLOCK_SIZE;
        break;
    case SHA256_DIGEST_SIZE:
        ctx->flags |= SHA_FLAGS_SHA256;
        ctx->block_size = SHA256_BLOCK_SIZE;
        break;
    case SHA384_DIGEST_SIZE:
        ctx->flags |= SHA_FLAGS_SHA384;
        ctx->block_size = SHA384_BLOCK_SIZE;
        break;
    case SHA512_DIGEST_SIZE:
        ctx->flags |= SHA_FLAGS_SHA512;
        ctx->block_size = SHA512_BLOCK_SIZE;
        break;
    default:
        return -EINVAL;
        break;
    }

    ctx->bufcnt = 0;
    ctx->digcnt[0] = 0;
    ctx->digcnt[1] = 0;
    ctx->buflen = SHA_BUFFER_LEN;

    return 0;
}

static void atmel_sha_write_ctrl(struct atmel_sha_dev *dd, int dma)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    u32 valmr = SHA_MR_MODE_AUTO;
    unsigned int i, hashsize = 0;

    if (likely(dma)) {
        if (!dd->caps.has_dma)
            atmel_sha_write(dd, SHA_IER, SHA_INT_TXBUFE);
        valmr = SHA_MR_MODE_PDC;
        if (dd->caps.has_dualbuff)
            valmr |= SHA_MR_DUALBUFF;
    } else {
        atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
    }

    switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
    case SHA_FLAGS_SHA1:
        valmr |= SHA_MR_ALGO_SHA1;
        hashsize = SHA1_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA224:
        valmr |= SHA_MR_ALGO_SHA224;
        hashsize = SHA256_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA256:
        valmr |= SHA_MR_ALGO_SHA256;
        hashsize = SHA256_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA384:
        valmr |= SHA_MR_ALGO_SHA384;
        hashsize = SHA512_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA512:
        valmr |= SHA_MR_ALGO_SHA512;
        hashsize = SHA512_DIGEST_SIZE;
        break;

    default:
        break;
    }

    /* Setting CR_FIRST only for the first iteration */
    if (!(ctx->digcnt[0] || ctx->digcnt[1])) {
        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
    } else if (dd->caps.has_uihv && (ctx->flags & SHA_FLAGS_RESTORE)) {
        const u32 *hash = (const u32 *)ctx->digest;

        /*
         * Restore the hardware context: update the User Initialize
         * Hash Value (UIHV) with the value saved when the latest
         * 'update' operation completed on this very same crypto
         * request.
         */
        ctx->flags &= ~SHA_FLAGS_RESTORE;
        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
        for (i = 0; i < hashsize / sizeof(u32); ++i)
            atmel_sha_write(dd, SHA_REG_DIN(i), hash[i]);
        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
        valmr |= SHA_MR_UIHV;
    }
    /*
     * WARNING: If the UIHV feature is not available, the hardware CANNOT
     * process concurrent requests: the internal registers used to store
     * the hash/digest are still set to the partial digest output values
     * computed during the latest round.
     */

    atmel_sha_write(dd, SHA_MR, valmr);
}

static int atmel_sha_xmit_cpu(struct atmel_sha_dev *dd, const u8 *buf,
                  size_t length, int final)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    int count, len32;
    const u32 *buffer = (const u32 *)buf;

    dev_dbg(dd->dev, "xmit_cpu: digcnt: 0x%llx 0x%llx, length: %d, final: %d\n",
        ctx->digcnt[1], ctx->digcnt[0], length, final);

    atmel_sha_write_ctrl(dd, 0);

    /* should be non-zero before next lines to disable clocks later */
    ctx->digcnt[0] += length;
    if (ctx->digcnt[0] < length)
        ctx->digcnt[1]++;

    if (final)
        dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

    len32 = DIV_ROUND_UP(length, sizeof(u32));

    dd->flags |= SHA_FLAGS_CPU;

    for (count = 0; count < len32; count++)
        atmel_sha_write(dd, SHA_REG_DIN(count), buffer[count]);

    return -EINPROGRESS;
}

static int atmel_sha_xmit_pdc(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
        size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    int len32;

    dev_dbg(dd->dev, "xmit_pdc: digcnt: 0x%llx 0x%llx, length: %d, final: %d\n",
        ctx->digcnt[1], ctx->digcnt[0], length1, final);

    len32 = DIV_ROUND_UP(length1, sizeof(u32));
    atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTDIS);
    atmel_sha_write(dd, SHA_TPR, dma_addr1);
    atmel_sha_write(dd, SHA_TCR, len32);

    len32 = DIV_ROUND_UP(length2, sizeof(u32));
    atmel_sha_write(dd, SHA_TNPR, dma_addr2);
    atmel_sha_write(dd, SHA_TNCR, len32);

    atmel_sha_write_ctrl(dd, 1);

    /* should be non-zero before next lines to disable clocks later */
    ctx->digcnt[0] += length1;
    if (ctx->digcnt[0] < length1)
        ctx->digcnt[1]++;

    if (final)
        dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

    dd->flags |=  SHA_FLAGS_DMA_ACTIVE;

    /* Start DMA transfer */
    atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTEN);

    return -EINPROGRESS;
}

static void atmel_sha_dma_callback(void *data)
{
    struct atmel_sha_dev *dd = data;

    /* dma_lch_in - completed - wait DATRDY */
    atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
}

static int atmel_sha_xmit_dma(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
        size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    struct dma_async_tx_descriptor  *in_desc;
    struct scatterlist sg[2];

    dev_dbg(dd->dev, "xmit_dma: digcnt: 0x%llx 0x%llx, length: %d, final: %d\n",
        ctx->digcnt[1], ctx->digcnt[0], length1, final);

    dd->dma_lch_in.dma_conf.src_maxburst = 16;
    dd->dma_lch_in.dma_conf.dst_maxburst = 16;

    dmaengine_slave_config(dd->dma_lch_in.chan, &dd->dma_lch_in.dma_conf);

    if (length2) {
        sg_init_table(sg, 2);
        sg_dma_address(&sg[0]) = dma_addr1;
        sg_dma_len(&sg[0]) = length1;
        sg_dma_address(&sg[1]) = dma_addr2;
        sg_dma_len(&sg[1]) = length2;
        in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 2,
            DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
    } else {
        sg_init_table(sg, 1);
        sg_dma_address(&sg[0]) = dma_addr1;
        sg_dma_len(&sg[0]) = length1;
        in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 1,
            DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
    }
    if (!in_desc)
        return -EINVAL;

    in_desc->callback = atmel_sha_dma_callback;
    in_desc->callback_param = dd;

    atmel_sha_write_ctrl(dd, 1);

    /* should be non-zero before next lines to disable clocks later */
    ctx->digcnt[0] += length1;
    if (ctx->digcnt[0] < length1)
        ctx->digcnt[1]++;

    if (final)
        dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

    dd->flags |=  SHA_FLAGS_DMA_ACTIVE;

    /* Start DMA transfer */
    dmaengine_submit(in_desc);
    dma_async_issue_pending(dd->dma_lch_in.chan);

    return -EINPROGRESS;
}

static int atmel_sha_xmit_start(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
        size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
    if (dd->caps.has_dma)
        return atmel_sha_xmit_dma(dd, dma_addr1, length1,
                dma_addr2, length2, final);
    else
        return atmel_sha_xmit_pdc(dd, dma_addr1, length1,
                dma_addr2, length2, final);
}

static int atmel_sha_update_cpu(struct atmel_sha_dev *dd)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    int bufcnt;

    atmel_sha_append_sg(ctx);
    atmel_sha_fill_padding(ctx, 0);
    bufcnt = ctx->bufcnt;
    ctx->bufcnt = 0;

    return atmel_sha_xmit_cpu(dd, ctx->buffer, bufcnt, 1);
}

static int atmel_sha_xmit_dma_map(struct atmel_sha_dev *dd,
                    struct atmel_sha_reqctx *ctx,
                    size_t length, int final)
{
    ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
                ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
    if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
        dev_err(dd->dev, "dma %u bytes error\n", ctx->buflen +
                ctx->block_size);
        return -EINVAL;
    }

    ctx->flags &= ~SHA_FLAGS_SG;

    /* next call does not fail... so no unmap in the case of error */
    return atmel_sha_xmit_start(dd, ctx->dma_addr, length, 0, 0, final);
}

static int atmel_sha_update_dma_slow(struct atmel_sha_dev *dd)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    unsigned int final;
    size_t count;

    atmel_sha_append_sg(ctx);

    final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;

    dev_dbg(dd->dev, "slow: bufcnt: %u, digcnt: 0x%llx 0x%llx, final: %d\n",
         ctx->bufcnt, ctx->digcnt[1], ctx->digcnt[0], final);

    if (final)
        atmel_sha_fill_padding(ctx, 0);

    if (final || (ctx->bufcnt == ctx->buflen)) {
        count = ctx->bufcnt;
        ctx->bufcnt = 0;
        return atmel_sha_xmit_dma_map(dd, ctx, count, final);
    }

    return 0;
}

static int atmel_sha_update_dma_start(struct atmel_sha_dev *dd)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
    unsigned int length, final, tail;
    struct scatterlist *sg;
    unsigned int count;

    if (!ctx->total)
        return 0;

    if (ctx->bufcnt || ctx->offset)
        return atmel_sha_update_dma_slow(dd);

    dev_dbg(dd->dev, "fast: digcnt: 0x%llx 0x%llx, bufcnt: %u, total: %u\n",
        ctx->digcnt[1], ctx->digcnt[0], ctx->bufcnt, ctx->total);

    sg = ctx->sg;

    if (!IS_ALIGNED(sg->offset, sizeof(u32)))
        return atmel_sha_update_dma_slow(dd);

    if (!sg_is_last(sg) && !IS_ALIGNED(sg->length, ctx->block_size))
        /* size is not ctx->block_size aligned */
        return atmel_sha_update_dma_slow(dd);

    length = min(ctx->total, sg->length);

    if (sg_is_last(sg)) {
        if (!(ctx->flags & SHA_FLAGS_FINUP)) {
            /* not last sg must be ctx->block_size aligned */
            tail = length & (ctx->block_size - 1);
            length -= tail;
        }
    }

    ctx->total -= length;
    ctx->offset = length; /* offset where to start slow */

    final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;

    /* Add padding */
    if (final) {
        tail = length & (ctx->block_size - 1);
        length -= tail;
        ctx->total += tail;
        ctx->offset = length; /* offset where to start slow */

        sg = ctx->sg;
        atmel_sha_append_sg(ctx);

        atmel_sha_fill_padding(ctx, length);

        ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
            ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
        if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
            dev_err(dd->dev, "dma %u bytes error\n",
                ctx->buflen + ctx->block_size);
            return -EINVAL;
        }

        if (length == 0) {
            ctx->flags &= ~SHA_FLAGS_SG;
            count = ctx->bufcnt;
            ctx->bufcnt = 0;
            return atmel_sha_xmit_start(dd, ctx->dma_addr, count, 0,
                    0, final);
        } else {
            ctx->sg = sg;
            if (!dma_map_sg(dd->dev, ctx->sg, 1,
                DMA_TO_DEVICE)) {
                    dev_err(dd->dev, "dma_map_sg  error\n");
                    return -EINVAL;
            }

            ctx->flags |= SHA_FLAGS_SG;

            count = ctx->bufcnt;
            ctx->bufcnt = 0;
            return atmel_sha_xmit_start(dd, sg_dma_address(ctx->sg),
                    length, ctx->dma_addr, count, final);
        }
    }

    if (!dma_map_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE)) {
        dev_err(dd->dev, "dma_map_sg  error\n");
        return -EINVAL;
    }

    ctx->flags |= SHA_FLAGS_SG;

    /* next call does not fail... so no unmap in the case of error */
    return atmel_sha_xmit_start(dd, sg_dma_address(ctx->sg), length, 0,
                                0, final);
}

static int atmel_sha_update_dma_stop(struct atmel_sha_dev *dd)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);

    if (ctx->flags & SHA_FLAGS_SG) {
        dma_unmap_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE);
        if (ctx->sg->length == ctx->offset) {
            ctx->sg = sg_next(ctx->sg);
            if (ctx->sg)
                ctx->offset = 0;
        }
        if (ctx->flags & SHA_FLAGS_PAD) {
            dma_unmap_single(dd->dev, ctx->dma_addr,
                ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
        }
    } else {
        dma_unmap_single(dd->dev, ctx->dma_addr, ctx->buflen +
                        ctx->block_size, DMA_TO_DEVICE);
    }

    return 0;
}

static int atmel_sha_update_req(struct atmel_sha_dev *dd)
{
    struct ahash_request *req = dd->req;
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    int err;

    dev_dbg(dd->dev, "update_req: total: %u, digcnt: 0x%llx 0x%llx\n",
        ctx->total, ctx->digcnt[1], ctx->digcnt[0]);

    if (ctx->flags & SHA_FLAGS_CPU)
        err = atmel_sha_update_cpu(dd);
    else
        err = atmel_sha_update_dma_start(dd);

    /* wait for dma completion before can take more data */
    dev_dbg(dd->dev, "update: err: %d, digcnt: 0x%llx 0%llx\n",
            err, ctx->digcnt[1], ctx->digcnt[0]);

    return err;
}

static int atmel_sha_final_req(struct atmel_sha_dev *dd)
{
    struct ahash_request *req = dd->req;
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    int err = 0;
    int count;

    if (ctx->bufcnt >= ATMEL_SHA_DMA_THRESHOLD) {
        atmel_sha_fill_padding(ctx, 0);
        count = ctx->bufcnt;
        ctx->bufcnt = 0;
        err = atmel_sha_xmit_dma_map(dd, ctx, count, 1);
    }
    /* faster to handle last block with cpu */
    else {
        atmel_sha_fill_padding(ctx, 0);
        count = ctx->bufcnt;
        ctx->bufcnt = 0;
        err = atmel_sha_xmit_cpu(dd, ctx->buffer, count, 1);
    }

    dev_dbg(dd->dev, "final_req: err: %d\n", err);

    return err;
}

static void atmel_sha_copy_hash(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    u32 *hash = (u32 *)ctx->digest;
    unsigned int i, hashsize;

    switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
    case SHA_FLAGS_SHA1:
        hashsize = SHA1_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA224:
    case SHA_FLAGS_SHA256:
        hashsize = SHA256_DIGEST_SIZE;
        break;

    case SHA_FLAGS_SHA384:
    case SHA_FLAGS_SHA512:
        hashsize = SHA512_DIGEST_SIZE;
        break;

    default:
        /* Should not happen... */
        return;
    }

    for (i = 0; i < hashsize / sizeof(u32); ++i)
        hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
    ctx->flags |= SHA_FLAGS_RESTORE;
}

static void atmel_sha_copy_ready_hash(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

    if (!req->result)
        return;

    if (ctx->flags & SHA_FLAGS_SHA1)
        memcpy(req->result, ctx->digest, SHA1_DIGEST_SIZE);
    else if (ctx->flags & SHA_FLAGS_SHA224)
        memcpy(req->result, ctx->digest, SHA224_DIGEST_SIZE);
    else if (ctx->flags & SHA_FLAGS_SHA256)
        memcpy(req->result, ctx->digest, SHA256_DIGEST_SIZE);
    else if (ctx->flags & SHA_FLAGS_SHA384)
        memcpy(req->result, ctx->digest, SHA384_DIGEST_SIZE);
    else
        memcpy(req->result, ctx->digest, SHA512_DIGEST_SIZE);
}

static int atmel_sha_finish(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    struct atmel_sha_dev *dd = ctx->dd;

    if (ctx->digcnt[0] || ctx->digcnt[1])
        atmel_sha_copy_ready_hash(req);

    dev_dbg(dd->dev, "digcnt: 0x%llx 0x%llx, bufcnt: %d\n", ctx->digcnt[1],
        ctx->digcnt[0], ctx->bufcnt);

    return 0;
}

static void atmel_sha_finish_req(struct ahash_request *req, int err)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    struct atmel_sha_dev *dd = ctx->dd;

    if (!err) {
        atmel_sha_copy_hash(req);
        if (SHA_FLAGS_FINAL & dd->flags)
            err = atmel_sha_finish(req);
    } else {
        ctx->flags |= SHA_FLAGS_ERROR;
    }

    /* atomic operation is not needed here */
    dd->flags &= ~(SHA_FLAGS_BUSY | SHA_FLAGS_FINAL | SHA_FLAGS_CPU |
            SHA_FLAGS_DMA_READY | SHA_FLAGS_OUTPUT_READY);

    clk_disable(dd->iclk);

    if (req->base.complete)
        req->base.complete(&req->base, err);

    /* handle new request */
    tasklet_schedule(&dd->queue_task);
}

static int atmel_sha_hw_init(struct atmel_sha_dev *dd)
{
    int err;

    err = clk_enable(dd->iclk);
    if (err)
        return err;

    if (!(SHA_FLAGS_INIT & dd->flags)) {
        atmel_sha_write(dd, SHA_CR, SHA_CR_SWRST);
        dd->flags |= SHA_FLAGS_INIT;
        dd->err = 0;
    }

    return 0;
}

static inline unsigned int atmel_sha_get_version(struct atmel_sha_dev *dd)
{
    return atmel_sha_read(dd, SHA_HW_VERSION) & 0x00000fff;
}

static void atmel_sha_hw_version_init(struct atmel_sha_dev *dd)
{
    atmel_sha_hw_init(dd);

    dd->hw_version = atmel_sha_get_version(dd);

    dev_info(dd->dev,
            "version: 0x%x\n", dd->hw_version);

    clk_disable(dd->iclk);
}

static int atmel_sha_handle_queue(struct atmel_sha_dev *dd,
                  struct ahash_request *req)
{
    struct crypto_async_request *async_req, *backlog;
    struct atmel_sha_reqctx *ctx;
    unsigned long flags;
    int err = 0, ret = 0;

    spin_lock_irqsave(&dd->lock, flags);
    if (req)
        ret = ahash_enqueue_request(&dd->queue, req);

    if (SHA_FLAGS_BUSY & dd->flags) {
        spin_unlock_irqrestore(&dd->lock, flags);
        return ret;
    }

    backlog = crypto_get_backlog(&dd->queue);
    async_req = crypto_dequeue_request(&dd->queue);
    if (async_req)
        dd->flags |= SHA_FLAGS_BUSY;

    spin_unlock_irqrestore(&dd->lock, flags);

    if (!async_req)
        return ret;

    if (backlog)
        backlog->complete(backlog, -EINPROGRESS);

    req = ahash_request_cast(async_req);
    dd->req = req;
    ctx = ahash_request_ctx(req);

    dev_dbg(dd->dev, "handling new req, op: %lu, nbytes: %d\n",
                        ctx->op, req->nbytes);

    err = atmel_sha_hw_init(dd);

    if (err)
        goto err1;

    if (ctx->op == SHA_OP_UPDATE) {
        err = atmel_sha_update_req(dd);
        if (err != -EINPROGRESS && (ctx->flags & SHA_FLAGS_FINUP))
            /* no final() after finup() */
            err = atmel_sha_final_req(dd);
    } else if (ctx->op == SHA_OP_FINAL) {
        err = atmel_sha_final_req(dd);
    }

err1:
    if (err != -EINPROGRESS)
        /* done_task will not finish it, so do it here */
        atmel_sha_finish_req(req, err);

    dev_dbg(dd->dev, "exit, err: %d\n", err);

    return ret;
}

static int atmel_sha_enqueue(struct ahash_request *req, unsigned int op)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
    struct atmel_sha_dev *dd = tctx->dd;

    ctx->op = op;

    return atmel_sha_handle_queue(dd, req);
}

static int atmel_sha_update(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

    if (!req->nbytes)
        return 0;

    ctx->total = req->nbytes;
    ctx->sg = req->src;
    ctx->offset = 0;

    if (ctx->flags & SHA_FLAGS_FINUP) {
        if (ctx->bufcnt + ctx->total < ATMEL_SHA_DMA_THRESHOLD)
            /* faster to use CPU for short transfers */
            ctx->flags |= SHA_FLAGS_CPU;
    } else if (ctx->bufcnt + ctx->total < ctx->buflen) {
        atmel_sha_append_sg(ctx);
        return 0;
    }
    return atmel_sha_enqueue(req, SHA_OP_UPDATE);
}

static int atmel_sha_final(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

    ctx->flags |= SHA_FLAGS_FINUP;

    if (ctx->flags & SHA_FLAGS_ERROR)
        return 0; /* uncompleted hash is not needed */

    if (ctx->flags & SHA_FLAGS_PAD)
        /* copy ready hash (+ finalize hmac) */
        return atmel_sha_finish(req);

    return atmel_sha_enqueue(req, SHA_OP_FINAL);
}

static int atmel_sha_finup(struct ahash_request *req)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
    int err1, err2;

    ctx->flags |= SHA_FLAGS_FINUP;

    err1 = atmel_sha_update(req);
    if (err1 == -EINPROGRESS || err1 == -EBUSY)
        return err1;

    /*
     * final() has to be always called to cleanup resources
     * even if udpate() failed, except EINPROGRESS
     */
    err2 = atmel_sha_final(req);

    return err1 ?: err2;
}

static int atmel_sha_digest(struct ahash_request *req)
{
    return atmel_sha_init(req) ?: atmel_sha_finup(req);
}


static int atmel_sha_export(struct ahash_request *req, void *out)
{
    const struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

    memcpy(out, ctx, sizeof(*ctx));
    return 0;
}

static int atmel_sha_import(struct ahash_request *req, const void *in)
{
    struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

    memcpy(ctx, in, sizeof(*ctx));
    return 0;
}

static int atmel_sha_cra_init(struct crypto_tfm *tfm)
{
    crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
                 sizeof(struct atmel_sha_reqctx));

    return 0;
}

static struct ahash_alg sha_1_256_algs[] = {
{
    .init       = atmel_sha_init,
    .update     = atmel_sha_update,
    .final      = atmel_sha_final,
    .finup      = atmel_sha_finup,
    .digest     = atmel_sha_digest,
    .export     = atmel_sha_export,
    .import     = atmel_sha_import,
    .halg = {
        .digestsize = SHA1_DIGEST_SIZE,
        .statesize  = sizeof(struct atmel_sha_reqctx),
        .base   = {
            .cra_name       = "sha1",
            .cra_driver_name    = "atmel-sha1",
            .cra_priority       = 100,
            .cra_flags      = CRYPTO_ALG_ASYNC,
            .cra_blocksize      = SHA1_BLOCK_SIZE,
            .cra_ctxsize        = sizeof(struct atmel_sha_ctx),
            .cra_alignmask      = 0,
            .cra_module     = THIS_MODULE,
            .cra_init       = atmel_sha_cra_init,
        }
    }
},
{
    .init       = atmel_sha_init,
    .update     = atmel_sha_update,
    .final      = atmel_sha_final,
    .finup      = atmel_sha_finup,
    .digest     = atmel_sha_digest,
    .export     = atmel_sha_export,
    .import     = atmel_sha_import,
    .halg = {
        .digestsize = SHA256_DIGEST_SIZE,
        .statesize  = sizeof(struct atmel_sha_reqctx),
        .base   = {
            .cra_name       = "sha256",
            .cra_driver_name    = "atmel-sha256",
            .cra_priority       = 100,
            .cra_flags      = CRYPTO_ALG_ASYNC,
            .cra_blocksize      = SHA256_BLOCK_SIZE,
            .cra_ctxsize        = sizeof(struct atmel_sha_ctx),
            .cra_alignmask      = 0,
            .cra_module     = THIS_MODULE,
            .cra_init       = atmel_sha_cra_init,
        }
    }
},
};

static struct ahash_alg sha_224_alg = {
    .init       = atmel_sha_init,
    .update     = atmel_sha_update,
    .final      = atmel_sha_final,
    .finup      = atmel_sha_finup,
    .digest     = atmel_sha_digest,
    .export     = atmel_sha_export,
    .import     = atmel_sha_import,
    .halg = {
        .digestsize = SHA224_DIGEST_SIZE,
        .statesize  = sizeof(struct atmel_sha_reqctx),
        .base   = {
            .cra_name       = "sha224",
            .cra_driver_name    = "atmel-sha224",
            .cra_priority       = 100,
            .cra_flags      = CRYPTO_ALG_ASYNC,
            .cra_blocksize      = SHA224_BLOCK_SIZE,
            .cra_ctxsize        = sizeof(struct atmel_sha_ctx),
            .cra_alignmask      = 0,
            .cra_module     = THIS_MODULE,
            .cra_init       = atmel_sha_cra_init,
        }
    }
};

static struct ahash_alg sha_384_512_algs[] = {
{
    .init       = atmel_sha_init,
    .update     = atmel_sha_update,
    .final      = atmel_sha_final,
    .finup      = atmel_sha_finup,
    .digest     = atmel_sha_digest,
    .export     = atmel_sha_export,
    .import     = atmel_sha_import,
    .halg = {
        .digestsize = SHA384_DIGEST_SIZE,
        .statesize  = sizeof(struct atmel_sha_reqctx),
        .base   = {
            .cra_name       = "sha384",
            .cra_driver_name    = "atmel-sha384",
            .cra_priority       = 100,
            .cra_flags      = CRYPTO_ALG_ASYNC,
            .cra_blocksize      = SHA384_BLOCK_SIZE,
            .cra_ctxsize        = sizeof(struct atmel_sha_ctx),
            .cra_alignmask      = 0x3,
            .cra_module     = THIS_MODULE,
            .cra_init       = atmel_sha_cra_init,
        }
    }
},
{
    .init       = atmel_sha_init,
    .update     = atmel_sha_update,
    .final      = atmel_sha_final,
    .finup      = atmel_sha_finup,
    .digest     = atmel_sha_digest,
    .export     = atmel_sha_export,
    .import     = atmel_sha_import,
    .halg = {
        .digestsize = SHA512_DIGEST_SIZE,
        .statesize  = sizeof(struct atmel_sha_reqctx),
        .base   = {
            .cra_name       = "sha512",
            .cra_driver_name    = "atmel-sha512",
            .cra_priority       = 100,
            .cra_flags      = CRYPTO_ALG_ASYNC,
            .cra_blocksize      = SHA512_BLOCK_SIZE,
            .cra_ctxsize        = sizeof(struct atmel_sha_ctx),
            .cra_alignmask      = 0x3,
            .cra_module     = THIS_MODULE,
            .cra_init       = atmel_sha_cra_init,
        }
    }
},
};

static void atmel_sha_queue_task(unsigned long data)
{
    struct atmel_sha_dev *dd = (struct atmel_sha_dev *)data;

    atmel_sha_handle_queue(dd, NULL);
}

static void atmel_sha_done_task(unsigned long data)
{
    struct atmel_sha_dev *dd = (struct atmel_sha_dev *)data;
    int err = 0;

    if (SHA_FLAGS_CPU & dd->flags) {
        if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
            dd->flags &= ~SHA_FLAGS_OUTPUT_READY;
            goto finish;
        }
    } else if (SHA_FLAGS_DMA_READY & dd->flags) {
        if (SHA_FLAGS_DMA_ACTIVE & dd->flags) {
            dd->flags &= ~SHA_FLAGS_DMA_ACTIVE;
            atmel_sha_update_dma_stop(dd);
            if (dd->err) {
                err = dd->err;
                goto finish;
            }
        }
        if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
            /* hash or semi-hash ready */
            dd->flags &= ~(SHA_FLAGS_DMA_READY |
                        SHA_FLAGS_OUTPUT_READY);
            err = atmel_sha_update_dma_start(dd);
            if (err != -EINPROGRESS)
                goto finish;
        }
    }
    return;

finish:
    /* finish curent request */
    atmel_sha_finish_req(dd->req, err);
}

static irqreturn_t atmel_sha_irq(int irq, void *dev_id)
{
    struct atmel_sha_dev *sha_dd = dev_id;
    u32 reg;

    reg = atmel_sha_read(sha_dd, SHA_ISR);
    if (reg & atmel_sha_read(sha_dd, SHA_IMR)) {
        atmel_sha_write(sha_dd, SHA_IDR, reg);
        if (SHA_FLAGS_BUSY & sha_dd->flags) {
            sha_dd->flags |= SHA_FLAGS_OUTPUT_READY;
            if (!(SHA_FLAGS_CPU & sha_dd->flags))
                sha_dd->flags |= SHA_FLAGS_DMA_READY;
            tasklet_schedule(&sha_dd->done_task);
        } else {
            dev_warn(sha_dd->dev, "SHA interrupt when no active requests.\n");
        }
        return IRQ_HANDLED;
    }

    return IRQ_NONE;
}

static void atmel_sha_unregister_algs(struct atmel_sha_dev *dd)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(sha_1_256_algs); i++)
        crypto_unregister_ahash(&sha_1_256_algs[i]);

    if (dd->caps.has_sha224)
        crypto_unregister_ahash(&sha_224_alg);

    if (dd->caps.has_sha_384_512) {
        for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++)
            crypto_unregister_ahash(&sha_384_512_algs[i]);
    }
}

static int atmel_sha_register_algs(struct atmel_sha_dev *dd)
{
    int err, i, j;

    for (i = 0; i < ARRAY_SIZE(sha_1_256_algs); i++) {
        err = crypto_register_ahash(&sha_1_256_algs[i]);
        if (err)
            goto err_sha_1_256_algs;
    }

    if (dd->caps.has_sha224) {
        err = crypto_register_ahash(&sha_224_alg);
        if (err)
            goto err_sha_224_algs;
    }

    if (dd->caps.has_sha_384_512) {
        for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++) {
            err = crypto_register_ahash(&sha_384_512_algs[i]);
            if (err)
                goto err_sha_384_512_algs;
        }
    }

    return 0;

err_sha_384_512_algs:
    for (j = 0; j < i; j++)
        crypto_unregister_ahash(&sha_384_512_algs[j]);
    crypto_unregister_ahash(&sha_224_alg);
err_sha_224_algs:
    i = ARRAY_SIZE(sha_1_256_algs);
err_sha_1_256_algs:
    for (j = 0; j < i; j++)
        crypto_unregister_ahash(&sha_1_256_algs[j]);

    return err;
}

static bool atmel_sha_filter(struct dma_chan *chan, void *slave)
{
    struct at_dma_slave *sl = slave;

    if (sl && sl->dma_dev == chan->device->dev) {
        chan->private = sl;
        return true;
    } else {
        return false;
    }
}

static int atmel_sha_dma_init(struct atmel_sha_dev *dd,
                struct crypto_platform_data *pdata)
{
    int err = -ENOMEM;
    dma_cap_mask_t mask_in;

    /* Try to grab DMA channel */
    dma_cap_zero(mask_in);
    dma_cap_set(DMA_SLAVE, mask_in);

    dd->dma_lch_in.chan = dma_request_slave_channel_compat(mask_in,
            atmel_sha_filter, &pdata->dma_slave->rxdata, dd->dev, "tx");
    if (!dd->dma_lch_in.chan) {
        dev_warn(dd->dev, "no DMA channel available\n");
        return err;
    }

    dd->dma_lch_in.dma_conf.direction = DMA_MEM_TO_DEV;
    dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
        SHA_REG_DIN(0);
    dd->dma_lch_in.dma_conf.src_maxburst = 1;
    dd->dma_lch_in.dma_conf.src_addr_width =
        DMA_SLAVE_BUSWIDTH_4_BYTES;
    dd->dma_lch_in.dma_conf.dst_maxburst = 1;
    dd->dma_lch_in.dma_conf.dst_addr_width =
        DMA_SLAVE_BUSWIDTH_4_BYTES;
    dd->dma_lch_in.dma_conf.device_fc = false;

    return 0;
}

static void atmel_sha_dma_cleanup(struct atmel_sha_dev *dd)
{
    dma_release_channel(dd->dma_lch_in.chan);
}

static void atmel_sha_get_cap(struct atmel_sha_dev *dd)
{

    dd->caps.has_dma = 0;
    dd->caps.has_dualbuff = 0;
    dd->caps.has_sha224 = 0;
    dd->caps.has_sha_384_512 = 0;
    dd->caps.has_uihv = 0;

    /* keep only major version number */
    switch (dd->hw_version & 0xff0) {
    case 0x510:
        dd->caps.has_dma = 1;
        dd->caps.has_dualbuff = 1;
        dd->caps.has_sha224 = 1;
        dd->caps.has_sha_384_512 = 1;
        dd->caps.has_uihv = 1;
        break;
    case 0x420:
        dd->caps.has_dma = 1;
        dd->caps.has_dualbuff = 1;
        dd->caps.has_sha224 = 1;
        dd->caps.has_sha_384_512 = 1;
        dd->caps.has_uihv = 1;
        break;
    case 0x410:
        dd->caps.has_dma = 1;
        dd->caps.has_dualbuff = 1;
        dd->caps.has_sha224 = 1;
        dd->caps.has_sha_384_512 = 1;
        break;
    case 0x400:
        dd->caps.has_dma = 1;
        dd->caps.has_dualbuff = 1;
        dd->caps.has_sha224 = 1;
        break;
    case 0x320:
        break;
    default:
        dev_warn(dd->dev,
                "Unmanaged sha version, set minimum capabilities\n");
        break;
    }
}

#if defined(CONFIG_OF)
static const struct of_device_id atmel_sha_dt_ids[] = {
    { .compatible = "atmel,at91sam9g46-sha" },
    { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, atmel_sha_dt_ids);

static struct crypto_platform_data *atmel_sha_of_init(struct platform_device *pdev)
{
    struct device_node *np = pdev->dev.of_node;
    struct crypto_platform_data *pdata;

    if (!np) {
        dev_err(&pdev->dev, "device node not found\n");
        return ERR_PTR(-EINVAL);
    }

    pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
    if (!pdata) {
        dev_err(&pdev->dev, "could not allocate memory for pdata\n");
        return ERR_PTR(-ENOMEM);
    }

    pdata->dma_slave = devm_kzalloc(&pdev->dev,
                    sizeof(*(pdata->dma_slave)),
                    GFP_KERNEL);
    if (!pdata->dma_slave) {
        dev_err(&pdev->dev, "could not allocate memory for dma_slave\n");
        return ERR_PTR(-ENOMEM);
    }

    return pdata;
}
#else /* CONFIG_OF */
static inline struct crypto_platform_data *atmel_sha_of_init(struct platform_device *dev)
{
    return ERR_PTR(-EINVAL);
}
#endif

static int atmel_sha_probe(struct platform_device *pdev)
{
    struct atmel_sha_dev *sha_dd;
    struct crypto_platform_data *pdata;
    struct device *dev = &pdev->dev;
    struct resource *sha_res;
    int err;

    sha_dd = devm_kzalloc(&pdev->dev, sizeof(*sha_dd), GFP_KERNEL);
    if (sha_dd == NULL) {
        dev_err(dev, "unable to alloc data struct.\n");
        err = -ENOMEM;
        goto sha_dd_err;
    }

    sha_dd->dev = dev;

    platform_set_drvdata(pdev, sha_dd);

    INIT_LIST_HEAD(&sha_dd->list);
    spin_lock_init(&sha_dd->lock);

    tasklet_init(&sha_dd->done_task, atmel_sha_done_task,
                    (unsigned long)sha_dd);
    tasklet_init(&sha_dd->queue_task, atmel_sha_queue_task,
                    (unsigned long)sha_dd);

    crypto_init_queue(&sha_dd->queue, ATMEL_SHA_QUEUE_LENGTH);

    sha_dd->irq = -1;

    /* Get the base address */
    sha_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!sha_res) {
        dev_err(dev, "no MEM resource info\n");
        err = -ENODEV;
        goto res_err;
    }
    sha_dd->phys_base = sha_res->start;

    /* Get the IRQ */
    sha_dd->irq = platform_get_irq(pdev,  0);
    if (sha_dd->irq < 0) {
        dev_err(dev, "no IRQ resource info\n");
        err = sha_dd->irq;
        goto res_err;
    }

    err = devm_request_irq(&pdev->dev, sha_dd->irq, atmel_sha_irq,
                   IRQF_SHARED, "atmel-sha", sha_dd);
    if (err) {
        dev_err(dev, "unable to request sha irq.\n");
        goto res_err;
    }

    /* Initializing the clock */
    sha_dd->iclk = devm_clk_get(&pdev->dev, "sha_clk");
    if (IS_ERR(sha_dd->iclk)) {
        dev_err(dev, "clock initialization failed.\n");
        err = PTR_ERR(sha_dd->iclk);
        goto res_err;
    }

    sha_dd->io_base = devm_ioremap_resource(&pdev->dev, sha_res);
    if (IS_ERR(sha_dd->io_base)) {
        dev_err(dev, "can't ioremap\n");
        err = PTR_ERR(sha_dd->io_base);
        goto res_err;
    }

    err = clk_prepare(sha_dd->iclk);
    if (err)
        goto res_err;

    atmel_sha_hw_version_init(sha_dd);

    atmel_sha_get_cap(sha_dd);

    if (sha_dd->caps.has_dma) {
        pdata = pdev->dev.platform_data;
        if (!pdata) {
            pdata = atmel_sha_of_init(pdev);
            if (IS_ERR(pdata)) {
                dev_err(&pdev->dev, "platform data not available\n");
                err = PTR_ERR(pdata);
                goto iclk_unprepare;
            }
        }
        if (!pdata->dma_slave) {
            err = -ENXIO;
            goto iclk_unprepare;
        }
        err = atmel_sha_dma_init(sha_dd, pdata);
        if (err)
            goto err_sha_dma;

        dev_info(dev, "using %s for DMA transfers\n",
                dma_chan_name(sha_dd->dma_lch_in.chan));
    }

    spin_lock(&atmel_sha.lock);
    list_add_tail(&sha_dd->list, &atmel_sha.dev_list);
    spin_unlock(&atmel_sha.lock);

    err = atmel_sha_register_algs(sha_dd);
    if (err)
        goto err_algs;

    dev_info(dev, "Atmel SHA1/SHA256%s%s\n",
            sha_dd->caps.has_sha224 ? "/SHA224" : "",
            sha_dd->caps.has_sha_384_512 ? "/SHA384/SHA512" : "");

    return 0;

err_algs:
    spin_lock(&atmel_sha.lock);
    list_del(&sha_dd->list);
    spin_unlock(&atmel_sha.lock);
    if (sha_dd->caps.has_dma)
        atmel_sha_dma_cleanup(sha_dd);
err_sha_dma:
iclk_unprepare:
    clk_unprepare(sha_dd->iclk);
res_err:
    tasklet_kill(&sha_dd->queue_task);
    tasklet_kill(&sha_dd->done_task);
sha_dd_err:
    dev_err(dev, "initialization failed.\n");

    return err;
}

static int atmel_sha_remove(struct platform_device *pdev)
{
    static struct atmel_sha_dev *sha_dd;

    sha_dd = platform_get_drvdata(pdev);
    if (!sha_dd)
        return -ENODEV;
    spin_lock(&atmel_sha.lock);
    list_del(&sha_dd->list);
    spin_unlock(&atmel_sha.lock);

    atmel_sha_unregister_algs(sha_dd);

    tasklet_kill(&sha_dd->queue_task);
    tasklet_kill(&sha_dd->done_task);

    if (sha_dd->caps.has_dma)
        atmel_sha_dma_cleanup(sha_dd);

    clk_unprepare(sha_dd->iclk);

    return 0;
}

static struct platform_driver atmel_sha_driver = {
    .probe      = atmel_sha_probe,
    .remove     = atmel_sha_remove,
    .driver     = {
        .name   = "atmel_sha",
        .of_match_table = of_match_ptr(atmel_sha_dt_ids),
    },
};

module_platform_driver(atmel_sha_driver);

MODULE_DESCRIPTION("Atmel SHA (1/256/224/384/512) hw acceleration support.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Nicolas Royer - Eukr茅a Electromatique");
發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章