crypto: bfin_crc - CRC hardware driver for BF60x family processors.
authorSonic Zhang <sonic.zhang@analog.com>
Mon, 4 Jun 2012 04:24:47 +0000 (12:24 +0800)
committerHerbert Xu <herbert@gondor.apana.org.au>
Tue, 12 Jun 2012 08:37:19 +0000 (16:37 +0800)
The CRC peripheral is a hardware block used to compute the CRC of the block
of data. This is based on a CRC32 engine which computes the CRC value of 32b
data words presented to it. For data words of < 32b in size, this driver
pack 0 automatically into 32b data units. This driver implements the async
hash crypto framework API.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
drivers/crypto/Kconfig
drivers/crypto/Makefile
drivers/crypto/bfin_crc.c [new file with mode: 0644]

index 1092a770482e53ce8597b39c9bba9dfa647db572..dd4d5af6c31f1bb5a6b01699b0864016f92ece55 100644 (file)
@@ -325,4 +325,11 @@ if CRYPTO_DEV_UX500
        source "drivers/crypto/ux500/Kconfig"
 endif # if CRYPTO_DEV_UX500
 
+config CRYPTO_DEV_BFIN_CRC
+       tristate "Support for Blackfin CRC hardware"
+       depends on BF60x
+       help
+         Newer Blackfin processors have CRC hardware. Select this if you
+         want to use the Blackfin CRC module.
+
 endif # CRYPTO_HW
index 01390325d72dd06fb1fbb6d362d12df4582229e4..d5062bb7a1f248160ecbe60bd10c4dc971a08dc9 100644 (file)
@@ -14,4 +14,5 @@ obj-$(CONFIG_CRYPTO_DEV_OMAP_AES) += omap-aes.o
 obj-$(CONFIG_CRYPTO_DEV_PICOXCELL) += picoxcell_crypto.o
 obj-$(CONFIG_CRYPTO_DEV_S5P) += s5p-sss.o
 obj-$(CONFIG_CRYPTO_DEV_TEGRA_AES) += tegra-aes.o
-obj-$(CONFIG_CRYPTO_DEV_UX500) += ux500/
\ No newline at end of file
+obj-$(CONFIG_CRYPTO_DEV_UX500) += ux500/
+obj-$(CONFIG_CRYPTO_DEV_BFIN_CRC) += bfin_crc.o
diff --git a/drivers/crypto/bfin_crc.c b/drivers/crypto/bfin_crc.c
new file mode 100644 (file)
index 0000000..5398580
--- /dev/null
@@ -0,0 +1,780 @@
+/*
+ * Cryptographic API.
+ *
+ * Support Blackfin CRC HW acceleration.
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/unaligned/access_ok.h>
+#include <linux/crypto.h>
+#include <linux/cryptohash.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/algapi.h>
+#include <crypto/hash.h>
+#include <crypto/internal/hash.h>
+
+#include <asm/blackfin.h>
+#include <asm/bfin_crc.h>
+#include <asm/dma.h>
+#include <asm/portmux.h>
+
+#define CRC_CCRYPTO_QUEUE_LENGTH       5
+
+#define DRIVER_NAME "bfin-hmac-crc"
+#define CHKSUM_DIGEST_SIZE      4
+#define CHKSUM_BLOCK_SIZE       1
+
+#define CRC_MAX_DMA_DESC       100
+
+#define CRC_CRYPTO_STATE_UPDATE                1
+#define CRC_CRYPTO_STATE_FINALUPDATE   2
+#define CRC_CRYPTO_STATE_FINISH                3
+
+struct bfin_crypto_crc {
+       struct list_head        list;
+       struct device           *dev;
+       spinlock_t              lock;
+
+       int                     irq;
+       int                     dma_ch;
+       u32                     poly;
+       volatile struct crc_register *regs;
+
+       struct ahash_request    *req; /* current request in operation */
+       struct dma_desc_array   *sg_cpu; /* virt addr of sg dma descriptors */
+       dma_addr_t              sg_dma; /* phy addr of sg dma descriptors */
+       u8                      *sg_mid_buf;
+
+       struct tasklet_struct   done_task;
+       struct crypto_queue     queue; /* waiting requests */
+
+       u8                      busy:1; /* crc device in operation flag */
+};
+
+static struct bfin_crypto_crc_list {
+       struct list_head        dev_list;
+       spinlock_t              lock;
+} crc_list;
+
+struct bfin_crypto_crc_reqctx {
+       struct bfin_crypto_crc  *crc;
+
+       unsigned int            total;  /* total request bytes */
+       size_t                  sg_buflen; /* bytes for this update */
+       unsigned int            sg_nents;
+       struct scatterlist      *sg; /* sg list head for this update*/
+       struct scatterlist      bufsl[2]; /* chained sg list */
+
+       size_t                  bufnext_len;
+       size_t                  buflast_len;
+       u8                      bufnext[CHKSUM_DIGEST_SIZE]; /* extra bytes for next udpate */
+       u8                      buflast[CHKSUM_DIGEST_SIZE]; /* extra bytes from last udpate */
+
+       u8                      flag;
+};
+
+struct bfin_crypto_crc_ctx {
+       struct bfin_crypto_crc  *crc;
+       u32                     key;
+};
+
+
+/*
+ * derive number of elements in scatterlist
+ */
+static int sg_count(struct scatterlist *sg_list)
+{
+       struct scatterlist *sg = sg_list;
+       int sg_nents = 1;
+
+       if (sg_list == NULL)
+               return 0;
+
+       while (!sg_is_last(sg)) {
+               sg_nents++;
+               sg = scatterwalk_sg_next(sg);
+       }
+
+       return sg_nents;
+}
+
+/*
+ * get element in scatter list by given index
+ */
+static struct scatterlist *sg_get(struct scatterlist *sg_list, unsigned int nents,
+                               unsigned int index)
+{
+       struct scatterlist *sg = NULL;
+       int i;
+
+       for_each_sg(sg_list, sg, nents, i)
+               if (i == index)
+                       break;
+
+       return sg;
+}
+
+static int bfin_crypto_crc_init_hw(struct bfin_crypto_crc *crc, u32 key)
+{
+       crc->regs->datacntrld = 0;
+       crc->regs->control = MODE_CALC_CRC << OPMODE_OFFSET;
+       crc->regs->curresult = key;
+
+       /* setup CRC interrupts */
+       crc->regs->status = CMPERRI | DCNTEXPI;
+       crc->regs->intrenset = CMPERRI | DCNTEXPI;
+       SSYNC();
+
+       return 0;
+}
+
+static int bfin_crypto_crc_init(struct ahash_request *req)
+{
+       struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+       struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
+       struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
+       struct bfin_crypto_crc *crc;
+
+       dev_dbg(crc->dev, "crc_init\n");
+       spin_lock_bh(&crc_list.lock);
+       list_for_each_entry(crc, &crc_list.dev_list, list) {
+               crc_ctx->crc = crc;
+               break;
+       }
+       spin_unlock_bh(&crc_list.lock);
+
+       if (sg_count(req->src) > CRC_MAX_DMA_DESC) {
+               dev_dbg(crc->dev, "init: requested sg list is too big > %d\n",
+                       CRC_MAX_DMA_DESC);
+               return -EINVAL;
+       }
+
+       ctx->crc = crc;
+       ctx->bufnext_len = 0;
+       ctx->buflast_len = 0;
+       ctx->sg_buflen = 0;
+       ctx->total = 0;
+       ctx->flag = 0;
+
+       /* init crc results */
+       put_unaligned_le32(crc_ctx->key, req->result);
+
+       dev_dbg(crc->dev, "init: digest size: %d\n",
+               crypto_ahash_digestsize(tfm));
+
+       return bfin_crypto_crc_init_hw(crc, crc_ctx->key);
+}
+
+static void bfin_crypto_crc_config_dma(struct bfin_crypto_crc *crc)
+{
+       struct scatterlist *sg;
+       struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(crc->req);
+       int i = 0, j = 0;
+       unsigned long dma_config;
+       unsigned int dma_count;
+       unsigned int dma_addr;
+       unsigned int mid_dma_count = 0;
+       int dma_mod;
+
+       dma_map_sg(crc->dev, ctx->sg, ctx->sg_nents, DMA_TO_DEVICE);
+
+       for_each_sg(ctx->sg, sg, ctx->sg_nents, j) {
+               dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 | DMAEN | PSIZE_32;
+               dma_addr = sg_dma_address(sg);
+               /* deduce extra bytes in last sg */
+               if (sg_is_last(sg))
+                       dma_count = sg_dma_len(sg) - ctx->bufnext_len;
+               else
+                       dma_count = sg_dma_len(sg);
+
+               if (mid_dma_count) {
+                       /* Append last middle dma buffer to 4 bytes with first
+                          bytes in current sg buffer. Move addr of current
+                          sg and deduce the length of current sg.
+                        */
+                       memcpy(crc->sg_mid_buf +((i-1) << 2) + mid_dma_count,
+                               (void *)dma_addr,
+                               CHKSUM_DIGEST_SIZE - mid_dma_count);
+                       dma_addr += CHKSUM_DIGEST_SIZE - mid_dma_count;
+                       dma_count -= CHKSUM_DIGEST_SIZE - mid_dma_count;
+               }
+               /* chop current sg dma len to multiple of 32 bits */
+               mid_dma_count = dma_count % 4;
+               dma_count &= ~0x3;
+
+               if (dma_addr % 4 == 0) {
+                       dma_config |= WDSIZE_32;
+                       dma_count >>= 2;
+                       dma_mod = 4;
+               } else if (dma_addr % 2 == 0) {
+                       dma_config |= WDSIZE_16;
+                       dma_count >>= 1;
+                       dma_mod = 2;
+               } else {
+                       dma_config |= WDSIZE_8;
+                       dma_mod = 1;
+               }
+
+               crc->sg_cpu[i].start_addr = dma_addr;
+               crc->sg_cpu[i].cfg = dma_config;
+               crc->sg_cpu[i].x_count = dma_count;
+               crc->sg_cpu[i].x_modify = dma_mod;
+               dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
+                       "cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
+                       i, crc->sg_cpu[i].start_addr,
+                       crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
+                       crc->sg_cpu[i].x_modify);
+               i++;
+
+               if (mid_dma_count) {
+                       /* copy extra bytes to next middle dma buffer */
+                       dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 |
+                               DMAEN | PSIZE_32 | WDSIZE_32;
+                       memcpy(crc->sg_mid_buf + (i << 2),
+                               (void *)(dma_addr + (dma_count << 2)),
+                               mid_dma_count);
+                       /* setup new dma descriptor for next middle dma */
+                       crc->sg_cpu[i].start_addr = dma_map_single(crc->dev,
+                                       crc->sg_mid_buf + (i << 2),
+                                       CHKSUM_DIGEST_SIZE, DMA_TO_DEVICE);
+                       crc->sg_cpu[i].cfg = dma_config;
+                       crc->sg_cpu[i].x_count = 1;
+                       crc->sg_cpu[i].x_modify = CHKSUM_DIGEST_SIZE;
+                       dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
+                               "cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
+                               i, crc->sg_cpu[i].start_addr,
+                               crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
+                               crc->sg_cpu[i].x_modify);
+                       i++;
+               }
+       }
+
+       dma_config = DMAFLOW_ARRAY | RESTART | NDSIZE_3 | DMAEN | PSIZE_32 | WDSIZE_32;
+       /* For final update req, append the buffer for next update as well*/
+       if (ctx->bufnext_len && (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE ||
+               ctx->flag == CRC_CRYPTO_STATE_FINISH)) {
+               crc->sg_cpu[i].start_addr = dma_map_single(crc->dev, ctx->bufnext,
+                                               CHKSUM_DIGEST_SIZE, DMA_TO_DEVICE);
+               crc->sg_cpu[i].cfg = dma_config;
+               crc->sg_cpu[i].x_count = 1;
+               crc->sg_cpu[i].x_modify = CHKSUM_DIGEST_SIZE;
+               dev_dbg(crc->dev, "%d: crc_dma: start_addr:0x%lx, "
+                       "cfg:0x%lx, x_count:0x%lx, x_modify:0x%lx\n",
+                       i, crc->sg_cpu[i].start_addr,
+                       crc->sg_cpu[i].cfg, crc->sg_cpu[i].x_count,
+                       crc->sg_cpu[i].x_modify);
+               i++;
+       }
+
+       if (i == 0)
+               return;
+
+       flush_dcache_range((unsigned int)crc->sg_cpu,
+                       (unsigned int)crc->sg_cpu +
+                       i * sizeof(struct dma_desc_array));
+
+       /* Set the last descriptor to stop mode */
+       crc->sg_cpu[i - 1].cfg &= ~(DMAFLOW | NDSIZE);
+       crc->sg_cpu[i - 1].cfg |= DI_EN;
+       set_dma_curr_desc_addr(crc->dma_ch, (unsigned long *)crc->sg_dma);
+       set_dma_x_count(crc->dma_ch, 0);
+       set_dma_x_modify(crc->dma_ch, 0);
+       SSYNC();
+       set_dma_config(crc->dma_ch, dma_config);
+}
+
+static int bfin_crypto_crc_handle_queue(struct bfin_crypto_crc *crc,
+                                 struct ahash_request *req)
+{
+       struct crypto_async_request *async_req, *backlog;
+       struct bfin_crypto_crc_reqctx *ctx;
+       struct scatterlist *sg;
+       int ret = 0;
+       int nsg, i, j;
+       unsigned int nextlen;
+       unsigned long flags;
+
+       spin_lock_irqsave(&crc->lock, flags);
+       if (req)
+               ret = ahash_enqueue_request(&crc->queue, req);
+       if (crc->busy) {
+               spin_unlock_irqrestore(&crc->lock, flags);
+               return ret;
+       }
+       backlog = crypto_get_backlog(&crc->queue);
+       async_req = crypto_dequeue_request(&crc->queue);
+       if (async_req)
+               crc->busy = 1;
+       spin_unlock_irqrestore(&crc->lock, flags);
+
+       if (!async_req)
+               return ret;
+
+       if (backlog)
+               backlog->complete(backlog, -EINPROGRESS);
+
+       req = ahash_request_cast(async_req);
+       crc->req = req;
+       ctx = ahash_request_ctx(req);
+       ctx->sg = NULL;
+       ctx->sg_buflen = 0;
+       ctx->sg_nents = 0;
+
+       dev_dbg(crc->dev, "handling new req, flag=%u, nbytes: %d\n",
+                                               ctx->flag, req->nbytes);
+
+       if (ctx->flag == CRC_CRYPTO_STATE_FINISH) {
+               if (ctx->bufnext_len == 0) {
+                       crc->busy = 0;
+                       return 0;
+               }
+
+               /* Pack last crc update buffer to 32bit */
+               memset(ctx->bufnext + ctx->bufnext_len, 0,
+                               CHKSUM_DIGEST_SIZE - ctx->bufnext_len);
+       } else {
+               /* Pack small data which is less than 32bit to buffer for next update. */
+               if (ctx->bufnext_len + req->nbytes < CHKSUM_DIGEST_SIZE) {
+                       memcpy(ctx->bufnext + ctx->bufnext_len,
+                               sg_virt(req->src), req->nbytes);
+                       ctx->bufnext_len += req->nbytes;
+                       if (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE &&
+                               ctx->bufnext_len) {
+                               goto finish_update;
+                       } else {
+                               crc->busy = 0;
+                               return 0;
+                       }
+               }
+
+               if (ctx->bufnext_len) {
+                       /* Chain in extra bytes of last update */
+                       ctx->buflast_len = ctx->bufnext_len;
+                       memcpy(ctx->buflast, ctx->bufnext, ctx->buflast_len);
+
+                       nsg = ctx->sg_buflen ? 2 : 1;
+                       sg_init_table(ctx->bufsl, nsg);
+                       sg_set_buf(ctx->bufsl, ctx->buflast, ctx->buflast_len);
+                       if (nsg > 1)
+                               scatterwalk_sg_chain(ctx->bufsl, nsg,
+                                               req->src);
+                       ctx->sg = ctx->bufsl;
+               } else
+                       ctx->sg = req->src;
+
+               /* Chop crc buffer size to multiple of 32 bit */
+               nsg = ctx->sg_nents = sg_count(ctx->sg);
+               ctx->sg_buflen = ctx->buflast_len + req->nbytes;
+               ctx->bufnext_len = ctx->sg_buflen % 4;
+               ctx->sg_buflen &= ~0x3;
+
+               if (ctx->bufnext_len) {
+                       /* copy extra bytes to buffer for next update */
+                       memset(ctx->bufnext, 0, CHKSUM_DIGEST_SIZE);
+                       nextlen = ctx->bufnext_len;
+                       for (i = nsg - 1; i >= 0; i--) {
+                               sg = sg_get(ctx->sg, nsg, i);
+                               j = min(nextlen, sg_dma_len(sg));
+                               memcpy(ctx->bufnext + nextlen - j,
+                                       sg_virt(sg) + sg_dma_len(sg) - j, j);
+                               if (j == sg_dma_len(sg))
+                                       ctx->sg_nents--;
+                               nextlen -= j;
+                               if (nextlen == 0)
+                                       break;
+                       }
+               }
+       }
+
+finish_update:
+       if (ctx->bufnext_len && (ctx->flag == CRC_CRYPTO_STATE_FINALUPDATE ||
+               ctx->flag == CRC_CRYPTO_STATE_FINISH))
+               ctx->sg_buflen += CHKSUM_DIGEST_SIZE;
+
+       /* set CRC data count before start DMA */
+       crc->regs->datacnt = ctx->sg_buflen >> 2;
+
+       /* setup and enable CRC DMA */
+       bfin_crypto_crc_config_dma(crc);
+
+       /* finally kick off CRC operation */
+       crc->regs->control |= BLKEN;
+       SSYNC();
+
+       return -EINPROGRESS;
+}
+
+static int bfin_crypto_crc_update(struct ahash_request *req)
+{
+       struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
+
+       if (!req->nbytes)
+               return 0;
+
+       dev_dbg(ctx->crc->dev, "crc_update\n");
+       ctx->total += req->nbytes;
+       ctx->flag = CRC_CRYPTO_STATE_UPDATE;
+
+       return bfin_crypto_crc_handle_queue(ctx->crc, req);
+}
+
+static int bfin_crypto_crc_final(struct ahash_request *req)
+{
+       struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+       struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
+       struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
+
+       dev_dbg(ctx->crc->dev, "crc_final\n");
+       ctx->flag = CRC_CRYPTO_STATE_FINISH;
+       crc_ctx->key = 0;
+
+       return bfin_crypto_crc_handle_queue(ctx->crc, req);
+}
+
+static int bfin_crypto_crc_finup(struct ahash_request *req)
+{
+       struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+       struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
+       struct bfin_crypto_crc_reqctx *ctx = ahash_request_ctx(req);
+
+       dev_dbg(ctx->crc->dev, "crc_finishupdate\n");
+       ctx->total += req->nbytes;
+       ctx->flag = CRC_CRYPTO_STATE_FINALUPDATE;
+       crc_ctx->key = 0;
+
+       return bfin_crypto_crc_handle_queue(ctx->crc, req);
+}
+
+static int bfin_crypto_crc_digest(struct ahash_request *req)
+{
+       int ret;
+
+       ret = bfin_crypto_crc_init(req);
+       if (ret)
+               return ret;
+
+       return bfin_crypto_crc_finup(req);
+}
+
+static int bfin_crypto_crc_setkey(struct crypto_ahash *tfm, const u8 *key,
+                       unsigned int keylen)
+{
+       struct bfin_crypto_crc_ctx *crc_ctx = crypto_ahash_ctx(tfm);
+
+       dev_dbg(crc_ctx->crc->dev, "crc_setkey\n");
+       if (keylen != CHKSUM_DIGEST_SIZE) {
+               crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+               return -EINVAL;
+       }
+
+       crc_ctx->key = get_unaligned_le32(key);
+
+       return 0;
+}
+
+static int bfin_crypto_crc_cra_init(struct crypto_tfm *tfm)
+{
+       struct bfin_crypto_crc_ctx *crc_ctx = crypto_tfm_ctx(tfm);
+
+       crc_ctx->key = 0;
+       crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+                                sizeof(struct bfin_crypto_crc_reqctx));
+
+       return 0;
+}
+
+static void bfin_crypto_crc_cra_exit(struct crypto_tfm *tfm)
+{
+}
+
+static struct ahash_alg algs = {
+       .init           = bfin_crypto_crc_init,
+       .update         = bfin_crypto_crc_update,
+       .final          = bfin_crypto_crc_final,
+       .finup          = bfin_crypto_crc_finup,
+       .digest         = bfin_crypto_crc_digest,
+       .setkey         = bfin_crypto_crc_setkey,
+       .halg.digestsize        = CHKSUM_DIGEST_SIZE,
+       .halg.base      = {
+               .cra_name               = "hmac(crc32)",
+               .cra_driver_name        = DRIVER_NAME,
+               .cra_priority           = 100,
+               .cra_flags              = CRYPTO_ALG_TYPE_AHASH |
+                                               CRYPTO_ALG_ASYNC,
+               .cra_blocksize          = CHKSUM_BLOCK_SIZE,
+               .cra_ctxsize            = sizeof(struct bfin_crypto_crc_ctx),
+               .cra_alignmask          = 3,
+               .cra_module             = THIS_MODULE,
+               .cra_init               = bfin_crypto_crc_cra_init,
+               .cra_exit               = bfin_crypto_crc_cra_exit,
+       }
+};
+
+static void bfin_crypto_crc_done_task(unsigned long data)
+{
+       struct bfin_crypto_crc *crc = (struct bfin_crypto_crc *)data;
+
+       bfin_crypto_crc_handle_queue(crc, NULL);
+}
+
+static irqreturn_t bfin_crypto_crc_handler(int irq, void *dev_id)
+{
+       struct bfin_crypto_crc *crc = dev_id;
+
+       if (crc->regs->status & DCNTEXP) {
+               crc->regs->status = DCNTEXP;
+               SSYNC();
+
+               /* prepare results */
+               put_unaligned_le32(crc->regs->result, crc->req->result);
+
+               crc->regs->control &= ~BLKEN;
+               crc->busy = 0;
+
+               if (crc->req->base.complete)
+                       crc->req->base.complete(&crc->req->base, 0);
+
+               tasklet_schedule(&crc->done_task);
+
+               return IRQ_HANDLED;
+       } else
+               return IRQ_NONE;
+}
+
+#ifdef CONFIG_PM
+/**
+ *     bfin_crypto_crc_suspend - suspend crc device
+ *     @pdev: device being suspended
+ *     @state: requested suspend state
+ */
+static int bfin_crypto_crc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+       struct bfin_crypto_crc *crc = platform_get_drvdata(pdev);
+       int i = 100000;
+
+       while ((crc->regs->control & BLKEN) && --i)
+               cpu_relax();
+
+       if (i == 0)
+               return -EBUSY;
+
+       return 0;
+}
+#else
+# define bfin_crypto_crc_suspend NULL
+#endif
+
+#define bfin_crypto_crc_resume NULL
+
+/**
+ *     bfin_crypto_crc_probe - Initialize module
+ *
+ */
+static int __devinit bfin_crypto_crc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct resource *res;
+       struct bfin_crypto_crc *crc;
+       unsigned int timeout = 100000;
+       int ret;
+
+       crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+       if (!crc) {
+               dev_err(&pdev->dev, "fail to malloc bfin_crypto_crc\n");
+               return -ENOMEM;
+       }
+
+       crc->dev = dev;
+
+       INIT_LIST_HEAD(&crc->list);
+       spin_lock_init(&crc->lock);
+       tasklet_init(&crc->done_task, bfin_crypto_crc_done_task, (unsigned long)crc);
+       crypto_init_queue(&crc->queue, CRC_CCRYPTO_QUEUE_LENGTH);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (res == NULL) {
+               dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
+               ret = -ENOENT;
+               goto out_error_free_mem;
+       }
+
+       crc->regs = ioremap(res->start, resource_size(res));
+       if (!crc->regs) {
+               dev_err(&pdev->dev, "Cannot map CRC IO\n");
+               ret = -ENXIO;
+               goto out_error_free_mem;
+       }
+
+       crc->irq = platform_get_irq(pdev, 0);
+       if (crc->irq < 0) {
+               dev_err(&pdev->dev, "No CRC DCNTEXP IRQ specified\n");
+               ret = -ENOENT;
+               goto out_error_unmap;
+       }
+
+       ret = request_irq(crc->irq, bfin_crypto_crc_handler, IRQF_SHARED, dev_name(dev), crc);
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to request blackfin crc irq\n");
+               goto out_error_unmap;
+       }
+
+       res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+       if (res == NULL) {
+               dev_err(&pdev->dev, "No CRC DMA channel specified\n");
+               ret = -ENOENT;
+               goto out_error_irq;
+       }
+       crc->dma_ch = res->start;
+
+       ret = request_dma(crc->dma_ch, dev_name(dev));
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to attach Blackfin CRC DMA channel\n");
+               goto out_error_irq;
+       }
+
+       crc->sg_cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE, &crc->sg_dma, GFP_KERNEL);
+       if (crc->sg_cpu == NULL) {
+               ret = -ENOMEM;
+               goto out_error_dma;
+       }
+       /*
+        * need at most CRC_MAX_DMA_DESC sg + CRC_MAX_DMA_DESC middle  +
+        * 1 last + 1 next dma descriptors
+        */
+       crc->sg_mid_buf = (u8 *)(crc->sg_cpu + ((CRC_MAX_DMA_DESC + 1) << 1));
+
+       crc->regs->control = 0;
+       SSYNC();
+       crc->regs->poly = crc->poly = (u32)pdev->dev.platform_data;
+       SSYNC();
+
+       while (!(crc->regs->status & LUTDONE) && (--timeout) > 0)
+               cpu_relax();
+
+       if (timeout == 0)
+               dev_info(&pdev->dev, "init crc poly timeout\n");
+
+       spin_lock(&crc_list.lock);
+       list_add(&crc->list, &crc_list.dev_list);
+       spin_unlock(&crc_list.lock);
+
+       platform_set_drvdata(pdev, crc);
+
+       ret = crypto_register_ahash(&algs);
+       if (ret) {
+               spin_lock(&crc_list.lock);
+               list_del(&crc->list);
+               spin_unlock(&crc_list.lock);
+               dev_err(&pdev->dev, "Cann't register crypto ahash device\n");
+               goto out_error_dma;
+       }
+
+       dev_info(&pdev->dev, "initialized\n");
+
+       return 0;
+
+out_error_dma:
+       if (crc->sg_cpu)
+               dma_free_coherent(&pdev->dev, PAGE_SIZE, crc->sg_cpu, crc->sg_dma);
+       free_dma(crc->dma_ch);
+out_error_irq:
+       free_irq(crc->irq, crc->dev);
+out_error_unmap:
+       iounmap((void *)crc->regs);
+out_error_free_mem:
+       kfree(crc);
+
+       return ret;
+}
+
+/**
+ *     bfin_crypto_crc_remove - Initialize module
+ *
+ */
+static int __devexit bfin_crypto_crc_remove(struct platform_device *pdev)
+{
+       struct bfin_crypto_crc *crc = platform_get_drvdata(pdev);
+
+       if (!crc)
+               return -ENODEV;
+
+       spin_lock(&crc_list.lock);
+       list_del(&crc->list);
+       spin_unlock(&crc_list.lock);
+
+       crypto_unregister_ahash(&algs);
+       tasklet_kill(&crc->done_task);
+       iounmap((void *)crc->regs);
+       free_dma(crc->dma_ch);
+       if (crc->irq > 0)
+               free_irq(crc->irq, crc->dev);
+       kfree(crc);
+
+       return 0;
+}
+
+static struct platform_driver bfin_crypto_crc_driver = {
+       .probe     = bfin_crypto_crc_probe,
+       .remove    = __devexit_p(bfin_crypto_crc_remove),
+       .suspend   = bfin_crypto_crc_suspend,
+       .resume    = bfin_crypto_crc_resume,
+       .driver    = {
+               .name  = DRIVER_NAME,
+               .owner = THIS_MODULE,
+       },
+};
+
+/**
+ *     bfin_crypto_crc_mod_init - Initialize module
+ *
+ *     Checks the module params and registers the platform driver.
+ *     Real work is in the platform probe function.
+ */
+static int __init bfin_crypto_crc_mod_init(void)
+{
+       int ret;
+
+       pr_info("Blackfin hardware CRC crypto driver\n");
+
+       INIT_LIST_HEAD(&crc_list.dev_list);
+       spin_lock_init(&crc_list.lock);
+
+       ret = platform_driver_register(&bfin_crypto_crc_driver);
+       if (ret) {
+               pr_info(KERN_ERR "unable to register driver\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+/**
+ *     bfin_crypto_crc_mod_exit - Deinitialize module
+ */
+static void __exit bfin_crypto_crc_mod_exit(void)
+{
+       platform_driver_unregister(&bfin_crypto_crc_driver);
+}
+
+module_init(bfin_crypto_crc_mod_init);
+module_exit(bfin_crypto_crc_mod_exit);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Blackfin CRC hardware crypto driver");
+MODULE_LICENSE("GPL");