crypto: omap-des - Add omap-des driver for OMAP4/AM43xx

Add omap-des driver with platform data for OMAP4/AM43xx. Support added for DES
ECB and CBC modes. Also add support for 3DES operation where 3 64-bit keys are
used to perform a DES encrypt-decrypt-encrypt (des3_ede) operation on a buffer.

Tests have been conducted with the CRYPTO test manager, and functionality is
verified at different page length alignments.

Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 1218 insertions, 0 deletions

diff --git a/drivers/crypto/omap-des.c b/drivers/crypto/omap-des.c
new file mode 100644
index 00000000000..006d9144485
--- /dev/null
+++ b/drivers/crypto/omap-des.c
@@ -0,0 +1,1218 @@
+/*
+ * Support for OMAP DES and Triple DES HW acceleration.
+ *
+ * Copyright (c) 2013 Texas Instruments Incorporated
+ * Author: Joel Fernandes <joelf@ti.com>
+ *
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#ifdef DEBUG
+#define prn(num) printk(#num "=%d\n", num)
+#define prx(num) printk(#num "=%x\n", num)
+#else
+#define prn(num) do { } while (0)
+#define prx(num)  do { } while (0)
+#endif
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/omap-dma.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/crypto.h>
+#include <linux/interrupt.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/des.h>
+
+#define DST_MAXBURST			2
+
+#define DES_BLOCK_WORDS		(DES_BLOCK_SIZE >> 2)
+
+#define _calc_walked(inout) (dd->inout##_walk.offset - dd->inout##_sg->offset)
+
+#define DES_REG_KEY(dd, x)		((dd)->pdata->key_ofs - \
+						((x ^ 0x01) * 0x04))
+
+#define DES_REG_IV(dd, x)		((dd)->pdata->iv_ofs + ((x) * 0x04))
+
+#define DES_REG_CTRL(dd)		((dd)->pdata->ctrl_ofs)
+#define DES_REG_CTRL_CBC		BIT(4)
+#define DES_REG_CTRL_TDES		BIT(3)
+#define DES_REG_CTRL_DIRECTION		BIT(2)
+#define DES_REG_CTRL_INPUT_READY	BIT(1)
+#define DES_REG_CTRL_OUTPUT_READY	BIT(0)
+
+#define DES_REG_DATA_N(dd, x)		((dd)->pdata->data_ofs + ((x) * 0x04))
+
+#define DES_REG_REV(dd)			((dd)->pdata->rev_ofs)
+
+#define DES_REG_MASK(dd)		((dd)->pdata->mask_ofs)
+
+#define DES_REG_LENGTH_N(x)		(0x24 + ((x) * 0x04))
+
+#define DES_REG_IRQ_STATUS(dd)         ((dd)->pdata->irq_status_ofs)
+#define DES_REG_IRQ_ENABLE(dd)         ((dd)->pdata->irq_enable_ofs)
+#define DES_REG_IRQ_DATA_IN            BIT(1)
+#define DES_REG_IRQ_DATA_OUT           BIT(2)
+
+#define FLAGS_MODE_MASK		0x000f
+#define FLAGS_ENCRYPT		BIT(0)
+#define FLAGS_CBC		BIT(1)
+#define FLAGS_INIT		BIT(4)
+#define FLAGS_BUSY		BIT(6)
+
+struct omap_des_ctx {
+	struct omap_des_dev *dd;
+
+	int		keylen;
+	u32		key[(3 * DES_KEY_SIZE) / sizeof(u32)];
+	unsigned long	flags;
+};
+
+struct omap_des_reqctx {
+	unsigned long mode;
+};
+
+#define OMAP_DES_QUEUE_LENGTH	1
+#define OMAP_DES_CACHE_SIZE	0
+
+struct omap_des_algs_info {
+	struct crypto_alg	*algs_list;
+	unsigned int		size;
+	unsigned int		registered;
+};
+
+struct omap_des_pdata {
+	struct omap_des_algs_info	*algs_info;
+	unsigned int	algs_info_size;
+
+	void		(*trigger)(struct omap_des_dev *dd, int length);
+
+	u32		key_ofs;
+	u32		iv_ofs;
+	u32		ctrl_ofs;
+	u32		data_ofs;
+	u32		rev_ofs;
+	u32		mask_ofs;
+	u32             irq_enable_ofs;
+	u32             irq_status_ofs;
+
+	u32		dma_enable_in;
+	u32		dma_enable_out;
+	u32		dma_start;
+
+	u32		major_mask;
+	u32		major_shift;
+	u32		minor_mask;
+	u32		minor_shift;
+};
+
+struct omap_des_dev {
+	struct list_head	list;
+	unsigned long		phys_base;
+	void __iomem		*io_base;
+	struct omap_des_ctx	*ctx;
+	struct device		*dev;
+	unsigned long		flags;
+	int			err;
+
+	/* spinlock used for queues */
+	spinlock_t		lock;
+	struct crypto_queue	queue;
+
+	struct tasklet_struct	done_task;
+	struct tasklet_struct	queue_task;
+
+	struct ablkcipher_request	*req;
+	/*
+	 * total is used by PIO mode for book keeping so introduce
+	 * variable total_save as need it to calc page_order
+	 */
+	size_t                          total;
+	size_t                          total_save;
+
+	struct scatterlist		*in_sg;
+	struct scatterlist		*out_sg;
+
+	/* Buffers for copying for unaligned cases */
+	struct scatterlist		in_sgl;
+	struct scatterlist		out_sgl;
+	struct scatterlist		*orig_out;
+	int				sgs_copied;
+
+	struct scatter_walk		in_walk;
+	struct scatter_walk		out_walk;
+	int			dma_in;
+	struct dma_chan		*dma_lch_in;
+	int			dma_out;
+	struct dma_chan		*dma_lch_out;
+	int			in_sg_len;
+	int			out_sg_len;
+	int			pio_only;
+	const struct omap_des_pdata	*pdata;
+};
+
+/* keep registered devices data here */
+static LIST_HEAD(dev_list);
+static DEFINE_SPINLOCK(list_lock);
+
+#ifdef DEBUG
+#define omap_des_read(dd, offset)                               \
+	({                                                              \
+	 int _read_ret;                                          \
+	 _read_ret = __raw_readl(dd->io_base + offset);          \
+	 pr_err("omap_des_read(" #offset "=%#x)= %#x\n",       \
+		 offset, _read_ret);                            \
+	 _read_ret;                                              \
+	 })
+#else
+static inline u32 omap_des_read(struct omap_des_dev *dd, u32 offset)
+{
+	return __raw_readl(dd->io_base + offset);
+}
+#endif
+
+#ifdef DEBUG
+#define omap_des_write(dd, offset, value)                               \
+	do {                                                            \
+		pr_err("omap_des_write(" #offset "=%#x) value=%#x\n", \
+				offset, value);                                \
+		__raw_writel(value, dd->io_base + offset);              \
+	} while (0)
+#else
+static inline void omap_des_write(struct omap_des_dev *dd, u32 offset,
+		u32 value)
+{
+	__raw_writel(value, dd->io_base + offset);
+}
+#endif
+
+static inline void omap_des_write_mask(struct omap_des_dev *dd, u32 offset,
+					u32 value, u32 mask)
+{
+	u32 val;
+
+	val = omap_des_read(dd, offset);
+	val &= ~mask;
+	val |= value;
+	omap_des_write(dd, offset, val);
+}
+
+static void omap_des_write_n(struct omap_des_dev *dd, u32 offset,
+					u32 *value, int count)
+{
+	for (; count--; value++, offset += 4)
+		omap_des_write(dd, offset, *value);
+}
+
+static int omap_des_hw_init(struct omap_des_dev *dd)
+{
+	/*
+	 * clocks are enabled when request starts and disabled when finished.
+	 * It may be long delays between requests.
+	 * Device might go to off mode to save power.
+	 */
+	pm_runtime_get_sync(dd->dev);
+
+	if (!(dd->flags & FLAGS_INIT)) {
+		dd->flags |= FLAGS_INIT;
+		dd->err = 0;
+	}
+
+	return 0;
+}
+
+static int omap_des_write_ctrl(struct omap_des_dev *dd)
+{
+	unsigned int key32;
+	int i, err;
+	u32 val = 0, mask = 0;
+
+	err = omap_des_hw_init(dd);
+	if (err)
+		return err;
+
+	key32 = dd->ctx->keylen / sizeof(u32);
+
+	/* it seems a key should always be set even if it has not changed */
+	for (i = 0; i < key32; i++) {
+		omap_des_write(dd, DES_REG_KEY(dd, i),
+			       __le32_to_cpu(dd->ctx->key[i]));
+	}
+
+	if ((dd->flags & FLAGS_CBC) && dd->req->info)
+		omap_des_write_n(dd, DES_REG_IV(dd, 0), dd->req->info, 2);
+
+	if (dd->flags & FLAGS_CBC)
+		val |= DES_REG_CTRL_CBC;
+	if (dd->flags & FLAGS_ENCRYPT)
+		val |= DES_REG_CTRL_DIRECTION;
+	if (key32 == 6)
+		val |= DES_REG_CTRL_TDES;
+
+	mask |= DES_REG_CTRL_CBC | DES_REG_CTRL_DIRECTION | DES_REG_CTRL_TDES;
+
+	omap_des_write_mask(dd, DES_REG_CTRL(dd), val, mask);
+
+	return 0;
+}
+
+static void omap_des_dma_trigger_omap4(struct omap_des_dev *dd, int length)
+{
+	u32 mask, val;
+
+	omap_des_write(dd, DES_REG_LENGTH_N(0), length);
+
+	val = dd->pdata->dma_start;
+
+	if (dd->dma_lch_out != NULL)
+		val |= dd->pdata->dma_enable_out;
+	if (dd->dma_lch_in != NULL)
+		val |= dd->pdata->dma_enable_in;
+
+	mask = dd->pdata->dma_enable_out | dd->pdata->dma_enable_in |
+	       dd->pdata->dma_start;
+
+	omap_des_write_mask(dd, DES_REG_MASK(dd), val, mask);
+}
+
+static void omap_des_dma_stop(struct omap_des_dev *dd)
+{
+	u32 mask;
+
+	mask = dd->pdata->dma_enable_out | dd->pdata->dma_enable_in |
+	       dd->pdata->dma_start;
+
+	omap_des_write_mask(dd, DES_REG_MASK(dd), 0, mask);
+}
+
+static struct omap_des_dev *omap_des_find_dev(struct omap_des_ctx *ctx)
+{
+	struct omap_des_dev *dd = NULL, *tmp;
+
+	spin_lock_bh(&list_lock);
+	if (!ctx->dd) {
+		list_for_each_entry(tmp, &dev_list, list) {
+			/* FIXME: take fist available des core */
+			dd = tmp;
+			break;
+		}
+		ctx->dd = dd;
+	} else {
+		/* already found before */
+		dd = ctx->dd;
+	}
+	spin_unlock_bh(&list_lock);
+
+	return dd;
+}
+
+static void omap_des_dma_out_callback(void *data)
+{
+	struct omap_des_dev *dd = data;
+
+	/* dma_lch_out - completed */
+	tasklet_schedule(&dd->done_task);
+}
+
+static int omap_des_dma_init(struct omap_des_dev *dd)
+{
+	int err = -ENOMEM;
+	dma_cap_mask_t mask;
+
+	dd->dma_lch_out = NULL;
+	dd->dma_lch_in = NULL;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	dd->dma_lch_in = dma_request_slave_channel_compat(mask,
+							  omap_dma_filter_fn,
+							  &dd->dma_in,
+							  dd->dev, "rx");
+	if (!dd->dma_lch_in) {
+		dev_err(dd->dev, "Unable to request in DMA channel\n");
+		goto err_dma_in;
+	}
+
+	dd->dma_lch_out = dma_request_slave_channel_compat(mask,
+							   omap_dma_filter_fn,
+							   &dd->dma_out,
+							   dd->dev, "tx");
+	if (!dd->dma_lch_out) {
+		dev_err(dd->dev, "Unable to request out DMA channel\n");
+		goto err_dma_out;
+	}
+
+	return 0;
+
+err_dma_out:
+	dma_release_channel(dd->dma_lch_in);
+err_dma_in:
+	if (err)
+		pr_err("error: %d\n", err);
+	return err;
+}
+
+static void omap_des_dma_cleanup(struct omap_des_dev *dd)
+{
+	dma_release_channel(dd->dma_lch_out);
+	dma_release_channel(dd->dma_lch_in);
+}
+
+static void sg_copy_buf(void *buf, struct scatterlist *sg,
+			      unsigned int start, unsigned int nbytes, int out)
+{
+	struct scatter_walk walk;
+
+	if (!nbytes)
+		return;
+
+	scatterwalk_start(&walk, sg);
+	scatterwalk_advance(&walk, start);
+	scatterwalk_copychunks(buf, &walk, nbytes, out);
+	scatterwalk_done(&walk, out, 0);
+}
+
+static int omap_des_crypt_dma(struct crypto_tfm *tfm,
+		struct scatterlist *in_sg, struct scatterlist *out_sg,
+		int in_sg_len, int out_sg_len)
+{
+	struct omap_des_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct omap_des_dev *dd = ctx->dd;
+	struct dma_async_tx_descriptor *tx_in, *tx_out;
+	struct dma_slave_config cfg;
+	int ret;
+
+	if (dd->pio_only) {
+		scatterwalk_start(&dd->in_walk, dd->in_sg);
+		scatterwalk_start(&dd->out_walk, dd->out_sg);
+
+		/* Enable DATAIN interrupt and let it take
+		   care of the rest */
+		omap_des_write(dd, DES_REG_IRQ_ENABLE(dd), 0x2);
+		return 0;
+	}
+
+	dma_sync_sg_for_device(dd->dev, dd->in_sg, in_sg_len, DMA_TO_DEVICE);
+
+	memset(&cfg, 0, sizeof(cfg));
+
+	cfg.src_addr = dd->phys_base + DES_REG_DATA_N(dd, 0);
+	cfg.dst_addr = dd->phys_base + DES_REG_DATA_N(dd, 0);
+	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	cfg.src_maxburst = DST_MAXBURST;
+	cfg.dst_maxburst = DST_MAXBURST;
+
+	/* IN */
+	ret = dmaengine_slave_config(dd->dma_lch_in, &cfg);
+	if (ret) {
+		dev_err(dd->dev, "can't configure IN dmaengine slave: %d\n",
+			ret);
+		return ret;
+	}
+
+	tx_in = dmaengine_prep_slave_sg(dd->dma_lch_in, in_sg, in_sg_len,
+					DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!tx_in) {
+		dev_err(dd->dev, "IN prep_slave_sg() failed\n");
+		return -EINVAL;
+	}
+
+	/* No callback necessary */
+	tx_in->callback_param = dd;
+
+	/* OUT */
+	ret = dmaengine_slave_config(dd->dma_lch_out, &cfg);
+	if (ret) {
+		dev_err(dd->dev, "can't configure OUT dmaengine slave: %d\n",
+			ret);
+		return ret;
+	}
+
+	tx_out = dmaengine_prep_slave_sg(dd->dma_lch_out, out_sg, out_sg_len,
+					DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!tx_out) {
+		dev_err(dd->dev, "OUT prep_slave_sg() failed\n");
+		return -EINVAL;
+	}
+
+	tx_out->callback = omap_des_dma_out_callback;
+	tx_out->callback_param = dd;
+
+	dmaengine_submit(tx_in);
+	dmaengine_submit(tx_out);
+
+	dma_async_issue_pending(dd->dma_lch_in);
+	dma_async_issue_pending(dd->dma_lch_out);
+
+	/* start DMA */
+	dd->pdata->trigger(dd, dd->total);
+
+	return 0;
+}
+
+static int omap_des_crypt_dma_start(struct omap_des_dev *dd)
+{
+	struct crypto_tfm *tfm = crypto_ablkcipher_tfm(
+					crypto_ablkcipher_reqtfm(dd->req));
+	int err;
+
+	pr_debug("total: %d\n", dd->total);
+
+	if (!dd->pio_only) {
+		err = dma_map_sg(dd->dev, dd->in_sg, dd->in_sg_len,
+				 DMA_TO_DEVICE);
+		if (!err) {
+			dev_err(dd->dev, "dma_map_sg() error\n");
+			return -EINVAL;
+		}
+
+		err = dma_map_sg(dd->dev, dd->out_sg, dd->out_sg_len,
+				 DMA_FROM_DEVICE);
+		if (!err) {
+			dev_err(dd->dev, "dma_map_sg() error\n");
+			return -EINVAL;
+		}
+	}
+
+	err = omap_des_crypt_dma(tfm, dd->in_sg, dd->out_sg, dd->in_sg_len,
+				 dd->out_sg_len);
+	if (err && !dd->pio_only) {
+		dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
+		dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len,
+			     DMA_FROM_DEVICE);
+	}
+
+	return err;
+}
+
+static void omap_des_finish_req(struct omap_des_dev *dd, int err)
+{
+	struct ablkcipher_request *req = dd->req;
+
+	pr_debug("err: %d\n", err);
+
+	pm_runtime_put(dd->dev);
+	dd->flags &= ~FLAGS_BUSY;
+
+	req->base.complete(&req->base, err);
+}
+
+static int omap_des_crypt_dma_stop(struct omap_des_dev *dd)
+{
+	int err = 0;
+
+	pr_debug("total: %d\n", dd->total);
+
+	omap_des_dma_stop(dd);
+
+	dmaengine_terminate_all(dd->dma_lch_in);
+	dmaengine_terminate_all(dd->dma_lch_out);
+
+	dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
+	dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len, DMA_FROM_DEVICE);
+
+	return err;
+}
+
+int omap_des_copy_needed(struct scatterlist *sg)
+{
+	while (sg) {
+		if (!IS_ALIGNED(sg->offset, 4))
+			return -1;
+		if (!IS_ALIGNED(sg->length, DES_BLOCK_SIZE))
+			return -1;
+		sg = sg_next(sg);
+	}
+	return 0;
+}
+
+int omap_des_copy_sgs(struct omap_des_dev *dd)
+{
+	void *buf_in, *buf_out;
+	int pages;
+
+	pages = dd->total >> PAGE_SHIFT;
+
+	if (dd->total & (PAGE_SIZE-1))
+		pages++;
+
+	BUG_ON(!pages);
+
+	buf_in = (void *)__get_free_pages(GFP_ATOMIC, pages);
+	buf_out = (void *)__get_free_pages(GFP_ATOMIC, pages);
+
+	if (!buf_in || !buf_out) {
+		pr_err("Couldn't allocated pages for unaligned cases.\n");
+		return -1;
+	}
+
+	dd->orig_out = dd->out_sg;
+
+	sg_copy_buf(buf_in, dd->in_sg, 0, dd->total, 0);
+
+	sg_init_table(&dd->in_sgl, 1);
+	sg_set_buf(&dd->in_sgl, buf_in, dd->total);
+	dd->in_sg = &dd->in_sgl;
+
+	sg_init_table(&dd->out_sgl, 1);
+	sg_set_buf(&dd->out_sgl, buf_out, dd->total);
+	dd->out_sg = &dd->out_sgl;
+
+	return 0;
+}
+
+static int omap_des_handle_queue(struct omap_des_dev *dd,
+			       struct ablkcipher_request *req)
+{
+	struct crypto_async_request *async_req, *backlog;
+	struct omap_des_ctx *ctx;
+	struct omap_des_reqctx *rctx;
+	unsigned long flags;
+	int err, ret = 0;
+
+	spin_lock_irqsave(&dd->lock, flags);
+	if (req)
+		ret = ablkcipher_enqueue_request(&dd->queue, req);
+	if (dd->flags & FLAGS_BUSY) {
+		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 |= FLAGS_BUSY;
+	spin_unlock_irqrestore(&dd->lock, flags);
+
+	if (!async_req)
+		return ret;
+
+	if (backlog)
+		backlog->complete(backlog, -EINPROGRESS);
+
+	req = ablkcipher_request_cast(async_req);
+
+	/* assign new request to device */
+	dd->req = req;
+	dd->total = req->nbytes;
+	dd->total_save = req->nbytes;
+	dd->in_sg = req->src;
+	dd->out_sg = req->dst;
+
+	if (omap_des_copy_needed(dd->in_sg) ||
+	    omap_des_copy_needed(dd->out_sg)) {
+		if (omap_des_copy_sgs(dd))
+			pr_err("Failed to copy SGs for unaligned cases\n");
+		dd->sgs_copied = 1;
+	} else {
+		dd->sgs_copied = 0;
+	}
+
+	dd->in_sg_len = scatterwalk_bytes_sglen(dd->in_sg, dd->total);
+	dd->out_sg_len = scatterwalk_bytes_sglen(dd->out_sg, dd->total);
+	BUG_ON(dd->in_sg_len < 0 || dd->out_sg_len < 0);
+
+	rctx = ablkcipher_request_ctx(req);
+	ctx = crypto_ablkcipher_ctx(crypto_ablkcipher_reqtfm(req));
+	rctx->mode &= FLAGS_MODE_MASK;
+	dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode;
+
+	dd->ctx = ctx;
+	ctx->dd = dd;
+
+	err = omap_des_write_ctrl(dd);
+	if (!err)
+		err = omap_des_crypt_dma_start(dd);
+	if (err) {
+		/* des_task will not finish it, so do it here */
+		omap_des_finish_req(dd, err);
+		tasklet_schedule(&dd->queue_task);
+	}
+
+	return ret; /* return ret, which is enqueue return value */
+}
+
+static void omap_des_done_task(unsigned long data)
+{
+	struct omap_des_dev *dd = (struct omap_des_dev *)data;
+	void *buf_in, *buf_out;
+	int pages;
+
+	pr_debug("enter done_task\n");
+
+	if (!dd->pio_only) {
+		dma_sync_sg_for_device(dd->dev, dd->out_sg, dd->out_sg_len,
+				       DMA_FROM_DEVICE);
+		dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
+		dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len,
+			     DMA_FROM_DEVICE);
+		omap_des_crypt_dma_stop(dd);
+	}
+
+	if (dd->sgs_copied) {
+		buf_in = sg_virt(&dd->in_sgl);
+		buf_out = sg_virt(&dd->out_sgl);
+
+		sg_copy_buf(buf_out, dd->orig_out, 0, dd->total_save, 1);
+
+		pages = get_order(dd->total_save);
+		free_pages((unsigned long)buf_in, pages);
+		free_pages((unsigned long)buf_out, pages);
+	}
+
+	omap_des_finish_req(dd, 0);
+	omap_des_handle_queue(dd, NULL);
+
+	pr_debug("exit\n");
+}
+
+static void omap_des_queue_task(unsigned long data)
+{
+	struct omap_des_dev *dd = (struct omap_des_dev *)data;
+
+	omap_des_handle_queue(dd, NULL);
+}
+
+static int omap_des_crypt(struct ablkcipher_request *req, unsigned long mode)
+{
+	struct omap_des_ctx *ctx = crypto_ablkcipher_ctx(
+			crypto_ablkcipher_reqtfm(req));
+	struct omap_des_reqctx *rctx = ablkcipher_request_ctx(req);
+	struct omap_des_dev *dd;
+
+	pr_debug("nbytes: %d, enc: %d, cbc: %d\n", req->nbytes,
+		 !!(mode & FLAGS_ENCRYPT),
+		 !!(mode & FLAGS_CBC));
+
+	if (!IS_ALIGNED(req->nbytes, DES_BLOCK_SIZE)) {
+		pr_err("request size is not exact amount of DES blocks\n");
+		return -EINVAL;
+	}
+
+	dd = omap_des_find_dev(ctx);
+	if (!dd)
+		return -ENODEV;
+
+	rctx->mode = mode;
+
+	return omap_des_handle_queue(dd, req);
+}
+
+/* ********************** ALG API ************************************ */
+
+static int omap_des_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+			   unsigned int keylen)
+{
+	struct omap_des_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+
+	if (keylen != DES_KEY_SIZE && keylen != (3*DES_KEY_SIZE))
+		return -EINVAL;
+
+	pr_debug("enter, keylen: %d\n", keylen);
+
+	memcpy(ctx->key, key, keylen);
+	ctx->keylen = keylen;
+
+	return 0;
+}
+
+static int omap_des_ecb_encrypt(struct ablkcipher_request *req)
+{
+	return omap_des_crypt(req, FLAGS_ENCRYPT);
+}
+
+static int omap_des_ecb_decrypt(struct ablkcipher_request *req)
+{
+	return omap_des_crypt(req, 0);
+}
+
+static int omap_des_cbc_encrypt(struct ablkcipher_request *req)
+{
+	return omap_des_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC);
+}
+
+static int omap_des_cbc_decrypt(struct ablkcipher_request *req)
+{
+	return omap_des_crypt(req, FLAGS_CBC);
+}
+
+static int omap_des_cra_init(struct crypto_tfm *tfm)
+{
+	pr_debug("enter\n");
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct omap_des_reqctx);
+
+	return 0;
+}
+
+static void omap_des_cra_exit(struct crypto_tfm *tfm)
+{
+	pr_debug("enter\n");
+}
+
+/* ********************** ALGS ************************************ */
+
+static struct crypto_alg algs_ecb_cbc[] = {
+{
+	.cra_name		= "ecb(des)",
+	.cra_driver_name	= "ecb-des-omap",
+	.cra_priority		= 100,
+	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_ASYNC,
+	.cra_blocksize		= DES_BLOCK_SIZE,
+	.cra_ctxsize		= sizeof(struct omap_des_ctx),
+	.cra_alignmask		= 0,
+	.cra_type		= &crypto_ablkcipher_type,
+	.cra_module		= THIS_MODULE,
+	.cra_init		= omap_des_cra_init,
+	.cra_exit		= omap_des_cra_exit,
+	.cra_u.ablkcipher = {
+		.min_keysize	= DES_KEY_SIZE,
+		.max_keysize	= DES_KEY_SIZE,
+		.setkey		= omap_des_setkey,
+		.encrypt	= omap_des_ecb_encrypt,
+		.decrypt	= omap_des_ecb_decrypt,
+	}
+},
+{
+	.cra_name		= "cbc(des)",
+	.cra_driver_name	= "cbc-des-omap",
+	.cra_priority		= 100,
+	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_ASYNC,
+	.cra_blocksize		= DES_BLOCK_SIZE,
+	.cra_ctxsize		= sizeof(struct omap_des_ctx),
+	.cra_alignmask		= 0,
+	.cra_type		= &crypto_ablkcipher_type,
+	.cra_module		= THIS_MODULE,
+	.cra_init		= omap_des_cra_init,
+	.cra_exit		= omap_des_cra_exit,
+	.cra_u.ablkcipher = {
+		.min_keysize	= DES_KEY_SIZE,
+		.max_keysize	= DES_KEY_SIZE,
+		.ivsize		= DES_BLOCK_SIZE,
+		.setkey		= omap_des_setkey,
+		.encrypt	= omap_des_cbc_encrypt,
+		.decrypt	= omap_des_cbc_decrypt,
+	}
+},
+{
+	.cra_name		= "ecb(des3_ede)",
+	.cra_driver_name	= "ecb-des3-omap",
+	.cra_priority		= 100,
+	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_ASYNC,
+	.cra_blocksize		= DES_BLOCK_SIZE,
+	.cra_ctxsize		= sizeof(struct omap_des_ctx),
+	.cra_alignmask		= 0,
+	.cra_type		= &crypto_ablkcipher_type,
+	.cra_module		= THIS_MODULE,
+	.cra_init		= omap_des_cra_init,
+	.cra_exit		= omap_des_cra_exit,
+	.cra_u.ablkcipher = {
+		.min_keysize	= 3*DES_KEY_SIZE,
+		.max_keysize	= 3*DES_KEY_SIZE,
+		.setkey		= omap_des_setkey,
+		.encrypt	= omap_des_ecb_encrypt,
+		.decrypt	= omap_des_ecb_decrypt,
+	}
+},
+{
+	.cra_name		= "cbc(des3_ede)",
+	.cra_driver_name	= "cbc-des3-omap",
+	.cra_priority		= 100,
+	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_ASYNC,
+	.cra_blocksize		= DES_BLOCK_SIZE,
+	.cra_ctxsize		= sizeof(struct omap_des_ctx),
+	.cra_alignmask		= 0,
+	.cra_type		= &crypto_ablkcipher_type,
+	.cra_module		= THIS_MODULE,
+	.cra_init		= omap_des_cra_init,
+	.cra_exit		= omap_des_cra_exit,
+	.cra_u.ablkcipher = {
+		.min_keysize	= 3*DES_KEY_SIZE,
+		.max_keysize	= 3*DES_KEY_SIZE,
+		.ivsize		= DES_BLOCK_SIZE,
+		.setkey		= omap_des_setkey,
+		.encrypt	= omap_des_cbc_encrypt,
+		.decrypt	= omap_des_cbc_decrypt,
+	}
+}
+};
+
+static struct omap_des_algs_info omap_des_algs_info_ecb_cbc[] = {
+	{
+		.algs_list	= algs_ecb_cbc,
+		.size		= ARRAY_SIZE(algs_ecb_cbc),
+	},
+};
+
+#ifdef CONFIG_OF
+static const struct omap_des_pdata omap_des_pdata_omap4 = {
+	.algs_info	= omap_des_algs_info_ecb_cbc,
+	.algs_info_size	= ARRAY_SIZE(omap_des_algs_info_ecb_cbc),
+	.trigger	= omap_des_dma_trigger_omap4,
+	.key_ofs	= 0x14,
+	.iv_ofs		= 0x18,
+	.ctrl_ofs	= 0x20,
+	.data_ofs	= 0x28,
+	.rev_ofs	= 0x30,
+	.mask_ofs	= 0x34,
+	.irq_status_ofs = 0x3c,
+	.irq_enable_ofs = 0x40,
+	.dma_enable_in	= BIT(5),
+	.dma_enable_out	= BIT(6),
+	.major_mask	= 0x0700,
+	.major_shift	= 8,
+	.minor_mask	= 0x003f,
+	.minor_shift	= 0,
+};
+
+static irqreturn_t omap_des_irq(int irq, void *dev_id)
+{
+	struct omap_des_dev *dd = dev_id;
+	u32 status, i;
+	u32 *src, *dst;
+
+	status = omap_des_read(dd, DES_REG_IRQ_STATUS(dd));
+	if (status & DES_REG_IRQ_DATA_IN) {
+		omap_des_write(dd, DES_REG_IRQ_ENABLE(dd), 0x0);
+
+		BUG_ON(!dd->in_sg);
+
+		BUG_ON(_calc_walked(in) > dd->in_sg->length);
+
+		src = sg_virt(dd->in_sg) + _calc_walked(in);
+
+		for (i = 0; i < DES_BLOCK_WORDS; i++) {
+			omap_des_write(dd, DES_REG_DATA_N(dd, i), *src);
+
+			scatterwalk_advance(&dd->in_walk, 4);
+			if (dd->in_sg->length == _calc_walked(in)) {
+				dd->in_sg = scatterwalk_sg_next(dd->in_sg);
+				if (dd->in_sg) {
+					scatterwalk_start(&dd->in_walk,
+							  dd->in_sg);
+					src = sg_virt(dd->in_sg) +
+					      _calc_walked(in);
+				}
+			} else {
+				src++;
+			}
+		}
+
+		/* Clear IRQ status */
+		status &= ~DES_REG_IRQ_DATA_IN;
+		omap_des_write(dd, DES_REG_IRQ_STATUS(dd), status);
+
+		/* Enable DATA_OUT interrupt */
+		omap_des_write(dd, DES_REG_IRQ_ENABLE(dd), 0x4);
+
+	} else if (status & DES_REG_IRQ_DATA_OUT) {
+		omap_des_write(dd, DES_REG_IRQ_ENABLE(dd), 0x0);
+
+		BUG_ON(!dd->out_sg);
+
+		BUG_ON(_calc_walked(out) > dd->out_sg->length);
+
+		dst = sg_virt(dd->out_sg) + _calc_walked(out);
+
+		for (i = 0; i < DES_BLOCK_WORDS; i++) {
+			*dst = omap_des_read(dd, DES_REG_DATA_N(dd, i));
+			scatterwalk_advance(&dd->out_walk, 4);
+			if (dd->out_sg->length == _calc_walked(out)) {
+				dd->out_sg = scatterwalk_sg_next(dd->out_sg);
+				if (dd->out_sg) {
+					scatterwalk_start(&dd->out_walk,
+							  dd->out_sg);
+					dst = sg_virt(dd->out_sg) +
+					      _calc_walked(out);
+				}
+			} else {
+				dst++;
+			}
+		}
+
+		dd->total -= DES_BLOCK_SIZE;
+
+		BUG_ON(dd->total < 0);
+
+		/* Clear IRQ status */
+		status &= ~DES_REG_IRQ_DATA_OUT;
+		omap_des_write(dd, DES_REG_IRQ_STATUS(dd), status);
+
+		if (!dd->total)
+			/* All bytes read! */
+			tasklet_schedule(&dd->done_task);
+		else
+			/* Enable DATA_IN interrupt for next block */
+			omap_des_write(dd, DES_REG_IRQ_ENABLE(dd), 0x2);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct of_device_id omap_des_of_match[] = {
+	{
+		.compatible	= "ti,omap4-des",
+		.data		= &omap_des_pdata_omap4,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, omap_des_of_match);
+
+static int omap_des_get_of(struct omap_des_dev *dd,
+		struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_device(of_match_ptr(omap_des_of_match), &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "no compatible OF match\n");
+		return -EINVAL;
+	}
+
+	dd->dma_out = -1; /* Dummy value that's unused */
+	dd->dma_in = -1; /* Dummy value that's unused */
+	dd->pdata = match->data;
+
+	return 0;
+}
+#else
+static int omap_des_get_of(struct omap_des_dev *dd,
+		struct device *dev)
+{
+	return -EINVAL;
+}
+#endif
+
+static int omap_des_get_pdev(struct omap_des_dev *dd,
+		struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *r;
+	int err = 0;
+
+	/* Get the DMA out channel */
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!r) {
+		dev_err(dev, "no DMA out resource info\n");
+		err = -ENODEV;
+		goto err;
+	}
+	dd->dma_out = r->start;
+
+	/* Get the DMA in channel */
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+	if (!r) {
+		dev_err(dev, "no DMA in resource info\n");
+		err = -ENODEV;
+		goto err;
+	}
+	dd->dma_in = r->start;
+
+	/* non-DT devices get pdata from pdev */
+	dd->pdata = pdev->dev.platform_data;
+
+err:
+	return err;
+}
+
+static int omap_des_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct omap_des_dev *dd;
+	struct crypto_alg *algp;
+	struct resource *res;
+	int err = -ENOMEM, i, j, irq = -1;
+	u32 reg;
+
+	dd = devm_kzalloc(dev, sizeof(struct omap_des_dev), GFP_KERNEL);
+	if (dd == NULL) {
+		dev_err(dev, "unable to alloc data struct.\n");
+		goto err_data;
+	}
+	dd->dev = dev;
+	platform_set_drvdata(pdev, dd);
+
+	spin_lock_init(&dd->lock);
+	crypto_init_queue(&dd->queue, OMAP_DES_QUEUE_LENGTH);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "no MEM resource info\n");
+		goto err_res;
+	}
+
+	err = (dev->of_node) ? omap_des_get_of(dd, pdev) :
+			       omap_des_get_pdev(dd, pdev);
+	if (err)
+		goto err_res;
+
+	dd->io_base = devm_request_and_ioremap(dev, res);
+	if (!dd->io_base) {
+		dev_err(dev, "can't ioremap\n");
+		err = -ENOMEM;
+		goto err_res;
+	}
+	dd->phys_base = res->start;
+
+	pm_runtime_enable(dev);
+	pm_runtime_get_sync(dev);
+
+	omap_des_dma_stop(dd);
+
+	reg = omap_des_read(dd, DES_REG_REV(dd));
+
+	pm_runtime_put_sync(dev);
+
+	dev_info(dev, "OMAP DES hw accel rev: %u.%u\n",
+		 (reg & dd->pdata->major_mask) >> dd->pdata->major_shift,
+		 (reg & dd->pdata->minor_mask) >> dd->pdata->minor_shift);
+
+	tasklet_init(&dd->done_task, omap_des_done_task, (unsigned long)dd);
+	tasklet_init(&dd->queue_task, omap_des_queue_task, (unsigned long)dd);
+
+	err = omap_des_dma_init(dd);
+	if (err && DES_REG_IRQ_STATUS(dd) && DES_REG_IRQ_ENABLE(dd)) {
+		dd->pio_only = 1;
+
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0) {
+			dev_err(dev, "can't get IRQ resource\n");
+			goto err_irq;
+		}
+
+		err = devm_request_irq(dev, irq, omap_des_irq, 0,
+				dev_name(dev), dd);
+		if (err) {
+			dev_err(dev, "Unable to grab omap-des IRQ\n");
+			goto err_irq;
+		}
+	}
+
+
+	INIT_LIST_HEAD(&dd->list);
+	spin_lock(&list_lock);
+	list_add_tail(&dd->list, &dev_list);
+	spin_unlock(&list_lock);
+
+	for (i = 0; i < dd->pdata->algs_info_size; i++) {
+		for (j = 0; j < dd->pdata->algs_info[i].size; j++) {
+			algp = &dd->pdata->algs_info[i].algs_list[j];
+
+			pr_debug("reg alg: %s\n", algp->cra_name);
+			INIT_LIST_HEAD(&algp->cra_list);
+
+			err = crypto_register_alg(algp);
+			if (err)
+				goto err_algs;
+
+			dd->pdata->algs_info[i].registered++;
+		}
+	}
+
+	return 0;
+err_algs:
+	for (i = dd->pdata->algs_info_size - 1; i >= 0; i--)
+		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)
+			crypto_unregister_alg(
+					&dd->pdata->algs_info[i].algs_list[j]);
+	if (!dd->pio_only)
+		omap_des_dma_cleanup(dd);
+err_irq:
+	tasklet_kill(&dd->done_task);
+	tasklet_kill(&dd->queue_task);
+	pm_runtime_disable(dev);
+err_res:
+	dd = NULL;
+err_data:
+	dev_err(dev, "initialization failed.\n");
+	return err;
+}
+
+static int omap_des_remove(struct platform_device *pdev)
+{
+	struct omap_des_dev *dd = platform_get_drvdata(pdev);
+	int i, j;
+
+	if (!dd)
+		return -ENODEV;
+
+	spin_lock(&list_lock);
+	list_del(&dd->list);
+	spin_unlock(&list_lock);
+
+	for (i = dd->pdata->algs_info_size - 1; i >= 0; i--)
+		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)
+			crypto_unregister_alg(
+					&dd->pdata->algs_info[i].algs_list[j]);
+
+	tasklet_kill(&dd->done_task);
+	tasklet_kill(&dd->queue_task);
+	omap_des_dma_cleanup(dd);
+	pm_runtime_disable(dd->dev);
+	dd = NULL;
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int omap_des_suspend(struct device *dev)
+{
+	pm_runtime_put_sync(dev);
+	return 0;
+}
+
+static int omap_des_resume(struct device *dev)
+{
+	pm_runtime_get_sync(dev);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops omap_des_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(omap_des_suspend, omap_des_resume)
+};
+
+static struct platform_driver omap_des_driver = {
+	.probe	= omap_des_probe,
+	.remove	= omap_des_remove,
+	.driver	= {
+		.name	= "omap-des",
+		.owner	= THIS_MODULE,
+		.pm	= &omap_des_pm_ops,
+		.of_match_table	= of_match_ptr(omap_des_of_match),
+	},
+};
+
+module_platform_driver(omap_des_driver);
+
+MODULE_DESCRIPTION("OMAP DES hw acceleration support.");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes <joelf@ti.com>");