[]..

+
+#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		(1 << 4)
+#define DES_REG_CTRL_TDES		(1 << 3)
+#define DES_REG_CTRL_DIRECTION		(1 << 2)
+#define DES_REG_CTRL_INPUT_READY	(1 << 1)
+#define DES_REG_CTRL_OUTPUT_READY	(1 << 0)

Why not use bitops like you have done below.

+
+#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_pdata {
+	struct omap_des_algs_info	*algs_info;
+	unsigned int	algs_info_size;
+
+	void		(*trigger)(struct omap_des_dev *dd, int length);

Is this really used? How does a DT platform pass function pointers?

+
+	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);
+

[]..

+
+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);

You seem to do a pm_runtime_get_sync() in omap_des_write_ctrl() and a
pm_runtime_put() here and not a pm_runtime_put_sync()?

+	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;
+}
+

[]..

+
+#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_res_of(struct omap_des_dev *dd,
+		struct device *dev, struct resource *res)
+{
+	struct device_node *node = dev->of_node;
+	const struct of_device_id *match;
+	int err = 0;
+
+	match = of_match_device(of_match_ptr(omap_des_of_match), dev);
+	if (!match) {
+		dev_err(dev, "no compatible OF match\n");
+		err = -EINVAL;
+		goto err;
+	}
+
+	err = of_address_to_resource(node, 0, res);

Do you really need to do this? DT should have already populated
a resource for you based on the 'reg' property.

+	if (err < 0) {
+		dev_err(dev, "can't translate OF node address\n");
+		err = -EINVAL;
+		goto err;
+	}
+
+	dd->dma_out = -1; /* Dummy value that's unused */
+	dd->dma_in = -1; /* Dummy value that's unused */
+
+	dd->pdata = match->data;
+
+err:
+	return err;
+}
+#else
+static const struct of_device_id omap_des_of_match[] = {
+	{},
+};

you don't need this if you use of_match_ptr()

+
+static int omap_des_get_res_of(struct omap_des_dev *dd,
+		struct device *dev, struct resource *res)
+{
+	return -EINVAL;
+}
+#endif
+
+static int omap_des_get_res_pdev(struct omap_des_dev *dd,
+		struct platform_device *pdev, struct resource *res)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *r;
+	int err = 0;
+
+	/* Get the base address */
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r) {
+		dev_err(dev, "no MEM resource info\n");
+		err = -ENODEV;
+		goto err;
+	}
+	memcpy(res, r, sizeof(*res));

I don't think you need any of this. Regardless of a DT or a
non-DT platform, you should be able to do a platform_get_resource()
for mem resources.

+
+	/* 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);
+
+	err = (dev->of_node) ? omap_des_get_res_of(dd, dev, &res) :
+			       omap_des_get_res_pdev(dd, pdev, &res);
+	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);

I know you seemed to have taken this from the omap-aes driver, but this
does not seem correct. Your system suspend callbacks shouldn't
really be using pm_runtime apis.
On OMAPs this is handled by the pm_domain level callbacks, in case
your device is not runtime suspended during system suspend.

+	return 0;
+}
+
+static int omap_des_resume(struct device *dev)
+{
+	pm_runtime_get_sync(dev);

Same here.
Btw, has the omap-aes or this driver been tested with system
suspend on any platfoms?

+	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	= omap_des_of_match,

You could use of_match_ptr() here and avoid having the empty
omap_des_of_match defined.

+	},
+};
+
+module_platform_driver(omap_des_driver);
+
+MODULE_DESCRIPTION("OMAP DES hw acceleration support.");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joel Fernandes [off-list ref]");