Merge branch 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM DMA engine updates from Russell King:
 "This looks scary at first glance, but what it is is:
   - a rework of the sa11x0 DMA engine driver merged during the previous
     cycle, to extract a common set of helper functions for DMA engine
     implementations.
   - conversion of amba-pl08x.c to use these helper functions.
   - addition of OMAP DMA engine driver (using these helper functions),
     and conversion of some of the OMAP DMA users to use DMA engine.

  Nothing in the helper functions is ARM specific, so I hope that other
  implementations can consolidate some of their code by making use of
  these helpers.

  This has been sitting in linux-next most of the merge cycle, and has
  been tested by several OMAP folk.  I've tested it on sa11x0 platforms,
  and given it my best shot on my broken platforms which have the
  amba-pl08x controller.

  The last point is the addition to feature-removal-schedule.txt, which
  will have a merge conflict.  Between myself and TI, we're planning to
  remove the old TI DMA implementation next year."

Fix up trivial add/add conflicts in Documentation/feature-removal-schedule.txt
and drivers/dma/{Kconfig,Makefile}

* 'dmaengine' of git://git.linaro.org/people/rmk/linux-arm: (53 commits)
  ARM: 7481/1: OMAP2+: omap2plus_defconfig: enable OMAP DMA engine
  ARM: 7464/1: mmc: omap_hsmmc: ensure probe returns error if DMA channel request fails
  Add feature removal of old OMAP private DMA implementation
  mtd: omap2: remove private DMA API implementation
  mtd: omap2: add DMA engine support
  spi: omap2-mcspi: remove private DMA API implementation
  spi: omap2-mcspi: add DMA engine support
  ARM: omap: remove mmc platform data dma_mask and initialization
  mmc: omap: remove private DMA API implementation
  mmc: omap: add DMA engine support
  mmc: omap_hsmmc: remove private DMA API implementation
  mmc: omap_hsmmc: add DMA engine support
  dmaengine: omap: add support for cyclic DMA
  dmaengine: omap: add support for setting fi
  dmaengine: omap: add support for returning residue in tx_state method
  dmaengine: add OMAP DMA engine driver
  dmaengine: sa11x0-dma: add cyclic DMA support
  dmaengine: sa11x0-dma: fix DMA residue support
  dmaengine: PL08x: ensure all descriptors are freed when channel is released
  dmaengine: PL08x: get rid of write only pool_ctr and free_txd locking
  ...

1 files changed, 669 insertions, 0 deletions

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
new file mode 100644
index 000000000000..ae0561826137
--- /dev/null
+++ b/drivers/dma/omap-dma.c
@@ -0,0 +1,669 @@
+/*
+ * OMAP DMAengine support
+ *
+ * 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.
+ */
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/omap-dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "virt-dma.h"
+#include <plat/dma.h>
+
+struct omap_dmadev {
+	struct dma_device ddev;
+	spinlock_t lock;
+	struct tasklet_struct task;
+	struct list_head pending;
+};
+
+struct omap_chan {
+	struct virt_dma_chan vc;
+	struct list_head node;
+
+	struct dma_slave_config	cfg;
+	unsigned dma_sig;
+	bool cyclic;
+
+	int dma_ch;
+	struct omap_desc *desc;
+	unsigned sgidx;
+};
+
+struct omap_sg {
+	dma_addr_t addr;
+	uint32_t en;		/* number of elements (24-bit) */
+	uint32_t fn;		/* number of frames (16-bit) */
+};
+
+struct omap_desc {
+	struct virt_dma_desc vd;
+	enum dma_transfer_direction dir;
+	dma_addr_t dev_addr;
+
+	int16_t fi;		/* for OMAP_DMA_SYNC_PACKET */
+	uint8_t es;		/* OMAP_DMA_DATA_TYPE_xxx */
+	uint8_t sync_mode;	/* OMAP_DMA_SYNC_xxx */
+	uint8_t sync_type;	/* OMAP_DMA_xxx_SYNC* */
+	uint8_t periph_port;	/* Peripheral port */
+
+	unsigned sglen;
+	struct omap_sg sg[0];
+};
+
+static const unsigned es_bytes[] = {
+	[OMAP_DMA_DATA_TYPE_S8] = 1,
+	[OMAP_DMA_DATA_TYPE_S16] = 2,
+	[OMAP_DMA_DATA_TYPE_S32] = 4,
+};
+
+static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
+{
+	return container_of(d, struct omap_dmadev, ddev);
+}
+
+static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct omap_chan, vc.chan);
+}
+
+static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
+{
+	return container_of(t, struct omap_desc, vd.tx);
+}
+
+static void omap_dma_desc_free(struct virt_dma_desc *vd)
+{
+	kfree(container_of(vd, struct omap_desc, vd));
+}
+
+static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
+	unsigned idx)
+{
+	struct omap_sg *sg = d->sg + idx;
+
+	if (d->dir == DMA_DEV_TO_MEM)
+		omap_set_dma_dest_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
+			OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
+	else
+		omap_set_dma_src_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
+			OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
+
+	omap_set_dma_transfer_params(c->dma_ch, d->es, sg->en, sg->fn,
+		d->sync_mode, c->dma_sig, d->sync_type);
+
+	omap_start_dma(c->dma_ch);
+}
+
+static void omap_dma_start_desc(struct omap_chan *c)
+{
+	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
+	struct omap_desc *d;
+
+	if (!vd) {
+		c->desc = NULL;
+		return;
+	}
+
+	list_del(&vd->node);
+
+	c->desc = d = to_omap_dma_desc(&vd->tx);
+	c->sgidx = 0;
+
+	if (d->dir == DMA_DEV_TO_MEM)
+		omap_set_dma_src_params(c->dma_ch, d->periph_port,
+			OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
+	else
+		omap_set_dma_dest_params(c->dma_ch, d->periph_port,
+			OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
+
+	omap_dma_start_sg(c, d, 0);
+}
+
+static void omap_dma_callback(int ch, u16 status, void *data)
+{
+	struct omap_chan *c = data;
+	struct omap_desc *d;
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	d = c->desc;
+	if (d) {
+		if (!c->cyclic) {
+			if (++c->sgidx < d->sglen) {
+				omap_dma_start_sg(c, d, c->sgidx);
+			} else {
+				omap_dma_start_desc(c);
+				vchan_cookie_complete(&d->vd);
+			}
+		} else {
+			vchan_cyclic_callback(&d->vd);
+		}
+	}
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+}
+
+/*
+ * This callback schedules all pending channels.  We could be more
+ * clever here by postponing allocation of the real DMA channels to
+ * this point, and freeing them when our virtual channel becomes idle.
+ *
+ * We would then need to deal with 'all channels in-use'
+ */
+static void omap_dma_sched(unsigned long data)
+{
+	struct omap_dmadev *d = (struct omap_dmadev *)data;
+	LIST_HEAD(head);
+
+	spin_lock_irq(&d->lock);
+	list_splice_tail_init(&d->pending, &head);
+	spin_unlock_irq(&d->lock);
+
+	while (!list_empty(&head)) {
+		struct omap_chan *c = list_first_entry(&head,
+			struct omap_chan, node);
+
+		spin_lock_irq(&c->vc.lock);
+		list_del_init(&c->node);
+		omap_dma_start_desc(c);
+		spin_unlock_irq(&c->vc.lock);
+	}
+}
+
+static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+
+	dev_info(c->vc.chan.device->dev, "allocating channel for %u\n", c->dma_sig);
+
+	return omap_request_dma(c->dma_sig, "DMA engine",
+		omap_dma_callback, c, &c->dma_ch);
+}
+
+static void omap_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+
+	vchan_free_chan_resources(&c->vc);
+	omap_free_dma(c->dma_ch);
+
+	dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig);
+}
+
+static size_t omap_dma_sg_size(struct omap_sg *sg)
+{
+	return sg->en * sg->fn;
+}
+
+static size_t omap_dma_desc_size(struct omap_desc *d)
+{
+	unsigned i;
+	size_t size;
+
+	for (size = i = 0; i < d->sglen; i++)
+		size += omap_dma_sg_size(&d->sg[i]);
+
+	return size * es_bytes[d->es];
+}
+
+static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
+{
+	unsigned i;
+	size_t size, es_size = es_bytes[d->es];
+
+	for (size = i = 0; i < d->sglen; i++) {
+		size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
+
+		if (size)
+			size += this_size;
+		else if (addr >= d->sg[i].addr &&
+			 addr < d->sg[i].addr + this_size)
+			size += d->sg[i].addr + this_size - addr;
+	}
+	return size;
+}
+
+static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
+	dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+	struct virt_dma_desc *vd;
+	enum dma_status ret;
+	unsigned long flags;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (ret == DMA_SUCCESS || !txstate)
+		return ret;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	vd = vchan_find_desc(&c->vc, cookie);
+	if (vd) {
+		txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
+	} else if (c->desc && c->desc->vd.tx.cookie == cookie) {
+		struct omap_desc *d = c->desc;
+		dma_addr_t pos;
+
+		if (d->dir == DMA_MEM_TO_DEV)
+			pos = omap_get_dma_src_pos(c->dma_ch);
+		else if (d->dir == DMA_DEV_TO_MEM)
+			pos = omap_get_dma_dst_pos(c->dma_ch);
+		else
+			pos = 0;
+
+		txstate->residue = omap_dma_desc_size_pos(d, pos);
+	} else {
+		txstate->residue = 0;
+	}
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+
+	return ret;
+}
+
+static void omap_dma_issue_pending(struct dma_chan *chan)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	if (vchan_issue_pending(&c->vc) && !c->desc) {
+		struct omap_dmadev *d = to_omap_dma_dev(chan->device);
+		spin_lock(&d->lock);
+		if (list_empty(&c->node))
+			list_add_tail(&c->node, &d->pending);
+		spin_unlock(&d->lock);
+		tasklet_schedule(&d->task);
+	}
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+}
+
+static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
+	struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
+	enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+	enum dma_slave_buswidth dev_width;
+	struct scatterlist *sgent;
+	struct omap_desc *d;
+	dma_addr_t dev_addr;
+	unsigned i, j = 0, es, en, frame_bytes, sync_type;
+	u32 burst;
+
+	if (dir == DMA_DEV_TO_MEM) {
+		dev_addr = c->cfg.src_addr;
+		dev_width = c->cfg.src_addr_width;
+		burst = c->cfg.src_maxburst;
+		sync_type = OMAP_DMA_SRC_SYNC;
+	} else if (dir == DMA_MEM_TO_DEV) {
+		dev_addr = c->cfg.dst_addr;
+		dev_width = c->cfg.dst_addr_width;
+		burst = c->cfg.dst_maxburst;
+		sync_type = OMAP_DMA_DST_SYNC;
+	} else {
+		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
+		return NULL;
+	}
+
+	/* Bus width translates to the element size (ES) */
+	switch (dev_width) {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		es = OMAP_DMA_DATA_TYPE_S8;
+		break;
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		es = OMAP_DMA_DATA_TYPE_S16;
+		break;
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		es = OMAP_DMA_DATA_TYPE_S32;
+		break;
+	default: /* not reached */
+		return NULL;
+	}
+
+	/* Now allocate and setup the descriptor. */
+	d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
+	if (!d)
+		return NULL;
+
+	d->dir = dir;
+	d->dev_addr = dev_addr;
+	d->es = es;
+	d->sync_mode = OMAP_DMA_SYNC_FRAME;
+	d->sync_type = sync_type;
+	d->periph_port = OMAP_DMA_PORT_TIPB;
+
+	/*
+	 * Build our scatterlist entries: each contains the address,
+	 * the number of elements (EN) in each frame, and the number of
+	 * frames (FN).  Number of bytes for this entry = ES * EN * FN.
+	 *
+	 * Burst size translates to number of elements with frame sync.
+	 * Note: DMA engine defines burst to be the number of dev-width
+	 * transfers.
+	 */
+	en = burst;
+	frame_bytes = es_bytes[es] * en;
+	for_each_sg(sgl, sgent, sglen, i) {
+		d->sg[j].addr = sg_dma_address(sgent);
+		d->sg[j].en = en;
+		d->sg[j].fn = sg_dma_len(sgent) / frame_bytes;
+		j++;
+	}
+
+	d->sglen = j;
+
+	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
+}
+
+static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
+	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+	size_t period_len, enum dma_transfer_direction dir, void *context)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+	enum dma_slave_buswidth dev_width;
+	struct omap_desc *d;
+	dma_addr_t dev_addr;
+	unsigned es, sync_type;
+	u32 burst;
+
+	if (dir == DMA_DEV_TO_MEM) {
+		dev_addr = c->cfg.src_addr;
+		dev_width = c->cfg.src_addr_width;
+		burst = c->cfg.src_maxburst;
+		sync_type = OMAP_DMA_SRC_SYNC;
+	} else if (dir == DMA_MEM_TO_DEV) {
+		dev_addr = c->cfg.dst_addr;
+		dev_width = c->cfg.dst_addr_width;
+		burst = c->cfg.dst_maxburst;
+		sync_type = OMAP_DMA_DST_SYNC;
+	} else {
+		dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
+		return NULL;
+	}
+
+	/* Bus width translates to the element size (ES) */
+	switch (dev_width) {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		es = OMAP_DMA_DATA_TYPE_S8;
+		break;
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		es = OMAP_DMA_DATA_TYPE_S16;
+		break;
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		es = OMAP_DMA_DATA_TYPE_S32;
+		break;
+	default: /* not reached */
+		return NULL;
+	}
+
+	/* Now allocate and setup the descriptor. */
+	d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
+	if (!d)
+		return NULL;
+
+	d->dir = dir;
+	d->dev_addr = dev_addr;
+	d->fi = burst;
+	d->es = es;
+	d->sync_mode = OMAP_DMA_SYNC_PACKET;
+	d->sync_type = sync_type;
+	d->periph_port = OMAP_DMA_PORT_MPUI;
+	d->sg[0].addr = buf_addr;
+	d->sg[0].en = period_len / es_bytes[es];
+	d->sg[0].fn = buf_len / period_len;
+	d->sglen = 1;
+
+	if (!c->cyclic) {
+		c->cyclic = true;
+		omap_dma_link_lch(c->dma_ch, c->dma_ch);
+		omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ);
+		omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ);
+	}
+
+	if (!cpu_class_is_omap1()) {
+		omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
+		omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
+	}
+
+	return vchan_tx_prep(&c->vc, &d->vd, DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+}
+
+static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg)
+{
+	if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
+	    cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
+		return -EINVAL;
+
+	memcpy(&c->cfg, cfg, sizeof(c->cfg));
+
+	return 0;
+}
+
+static int omap_dma_terminate_all(struct omap_chan *c)
+{
+	struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+
+	/* Prevent this channel being scheduled */
+	spin_lock(&d->lock);
+	list_del_init(&c->node);
+	spin_unlock(&d->lock);
+
+	/*
+	 * Stop DMA activity: we assume the callback will not be called
+	 * after omap_stop_dma() returns (even if it does, it will see
+	 * c->desc is NULL and exit.)
+	 */
+	if (c->desc) {
+		c->desc = NULL;
+		omap_stop_dma(c->dma_ch);
+	}
+
+	if (c->cyclic) {
+		c->cyclic = false;
+		omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
+	}
+
+	vchan_get_all_descriptors(&c->vc, &head);
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+	vchan_dma_desc_free_list(&c->vc, &head);
+
+	return 0;
+}
+
+static int omap_dma_pause(struct omap_chan *c)
+{
+	/* FIXME: not supported by platform private API */
+	return -EINVAL;
+}
+
+static int omap_dma_resume(struct omap_chan *c)
+{
+	/* FIXME: not supported by platform private API */
+	return -EINVAL;
+}
+
+static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+	unsigned long arg)
+{
+	struct omap_chan *c = to_omap_dma_chan(chan);
+	int ret;
+
+	switch (cmd) {
+	case DMA_SLAVE_CONFIG:
+		ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg);
+		break;
+
+	case DMA_TERMINATE_ALL:
+		ret = omap_dma_terminate_all(c);
+		break;
+
+	case DMA_PAUSE:
+		ret = omap_dma_pause(c);
+		break;
+
+	case DMA_RESUME:
+		ret = omap_dma_resume(c);
+		break;
+
+	default:
+		ret = -ENXIO;
+		break;
+	}
+
+	return ret;
+}
+
+static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
+{
+	struct omap_chan *c;
+
+	c = kzalloc(sizeof(*c), GFP_KERNEL);
+	if (!c)
+		return -ENOMEM;
+
+	c->dma_sig = dma_sig;
+	c->vc.desc_free = omap_dma_desc_free;
+	vchan_init(&c->vc, &od->ddev);
+	INIT_LIST_HEAD(&c->node);
+
+	od->ddev.chancnt++;
+
+	return 0;
+}
+
+static void omap_dma_free(struct omap_dmadev *od)
+{
+	tasklet_kill(&od->task);
+	while (!list_empty(&od->ddev.channels)) {
+		struct omap_chan *c = list_first_entry(&od->ddev.channels,
+			struct omap_chan, vc.chan.device_node);
+
+		list_del(&c->vc.chan.device_node);
+		tasklet_kill(&c->vc.task);
+		kfree(c);
+	}
+	kfree(od);
+}
+
+static int omap_dma_probe(struct platform_device *pdev)
+{
+	struct omap_dmadev *od;
+	int rc, i;
+
+	od = kzalloc(sizeof(*od), GFP_KERNEL);
+	if (!od)
+		return -ENOMEM;
+
+	dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
+	dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
+	od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
+	od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
+	od->ddev.device_tx_status = omap_dma_tx_status;
+	od->ddev.device_issue_pending = omap_dma_issue_pending;
+	od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
+	od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
+	od->ddev.device_control = omap_dma_control;
+	od->ddev.dev = &pdev->dev;
+	INIT_LIST_HEAD(&od->ddev.channels);
+	INIT_LIST_HEAD(&od->pending);
+	spin_lock_init(&od->lock);
+
+	tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
+
+	for (i = 0; i < 127; i++) {
+		rc = omap_dma_chan_init(od, i);
+		if (rc) {
+			omap_dma_free(od);
+			return rc;
+		}
+	}
+
+	rc = dma_async_device_register(&od->ddev);
+	if (rc) {
+		pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
+			rc);
+		omap_dma_free(od);
+	} else {
+		platform_set_drvdata(pdev, od);
+	}
+
+	dev_info(&pdev->dev, "OMAP DMA engine driver\n");
+
+	return rc;
+}
+
+static int omap_dma_remove(struct platform_device *pdev)
+{
+	struct omap_dmadev *od = platform_get_drvdata(pdev);
+
+	dma_async_device_unregister(&od->ddev);
+	omap_dma_free(od);
+
+	return 0;
+}
+
+static struct platform_driver omap_dma_driver = {
+	.probe	= omap_dma_probe,
+	.remove	= omap_dma_remove,
+	.driver = {
+		.name = "omap-dma-engine",
+		.owner = THIS_MODULE,
+	},
+};
+
+bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+	if (chan->device->dev->driver == &omap_dma_driver.driver) {
+		struct omap_chan *c = to_omap_dma_chan(chan);
+		unsigned req = *(unsigned *)param;
+
+		return req == c->dma_sig;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
+
+static struct platform_device *pdev;
+
+static const struct platform_device_info omap_dma_dev_info = {
+	.name = "omap-dma-engine",
+	.id = -1,
+	.dma_mask = DMA_BIT_MASK(32),
+};
+
+static int omap_dma_init(void)
+{
+	int rc = platform_driver_register(&omap_dma_driver);
+
+	if (rc == 0) {
+		pdev = platform_device_register_full(&omap_dma_dev_info);
+		if (IS_ERR(pdev)) {
+			platform_driver_unregister(&omap_dma_driver);
+			rc = PTR_ERR(pdev);
+		}
+	}
+	return rc;
+}
+subsys_initcall(omap_dma_init);
+
+static void __exit omap_dma_exit(void)
+{
+	platform_device_unregister(pdev);
+	platform_driver_unregister(&omap_dma_driver);
+}
+module_exit(omap_dma_exit);
+
+MODULE_AUTHOR("Russell King");
+MODULE_LICENSE("GPL");