rapidio/tsi721: add DMA engine support

Adds support for DMA Engine API into Tsi721 mport driver.

Includes following changes for Tsi721 driver:
- Modifies BDMA register offset definitions to support per-channel handling
- Separates BDMA channel reserved for RIO Maintenance requests
- Adds DMA Engine callback routines

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 823 insertions, 0 deletions

diff --git a/drivers/rapidio/devices/tsi721_dma.c b/drivers/rapidio/devices/tsi721_dma.c
new file mode 100644
index 00000000000..92e06a5c62e
--- /dev/null
+++ b/drivers/rapidio/devices/tsi721_dma.c
@@ -0,0 +1,823 @@
+/*
+ * DMA Engine support for Tsi721 PCIExpress-to-SRIO bridge
+ *
+ * Copyright 2011 Integrated Device Technology, Inc.
+ * Alexandre Bounine <alexandre.bounine@idt.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rio.h>
+#include <linux/rio_drv.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/delay.h>
+
+#include "tsi721.h"
+
+static inline struct tsi721_bdma_chan *to_tsi721_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct tsi721_bdma_chan, dchan);
+}
+
+static inline struct tsi721_device *to_tsi721(struct dma_device *ddev)
+{
+	return container_of(ddev, struct rio_mport, dma)->priv;
+}
+
+static inline
+struct tsi721_tx_desc *to_tsi721_desc(struct dma_async_tx_descriptor *txd)
+{
+	return container_of(txd, struct tsi721_tx_desc, txd);
+}
+
+static inline
+struct tsi721_tx_desc *tsi721_dma_first_active(
+				struct tsi721_bdma_chan *bdma_chan)
+{
+	return list_first_entry(&bdma_chan->active_list,
+				struct tsi721_tx_desc, desc_node);
+}
+
+static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_dma_desc *bd_ptr;
+	struct device *dev = bdma_chan->dchan.device->dev;
+	u64		*sts_ptr;
+	dma_addr_t	bd_phys;
+	dma_addr_t	sts_phys;
+	int		sts_size;
+	int		bd_num = bdma_chan->bd_num;
+
+	dev_dbg(dev, "Init Block DMA Engine, CH%d\n", bdma_chan->id);
+
+	/* Allocate space for DMA descriptors */
+	bd_ptr = dma_zalloc_coherent(dev,
+				bd_num * sizeof(struct tsi721_dma_desc),
+				&bd_phys, GFP_KERNEL);
+	if (!bd_ptr)
+		return -ENOMEM;
+
+	bdma_chan->bd_phys = bd_phys;
+	bdma_chan->bd_base = bd_ptr;
+
+	dev_dbg(dev, "DMA descriptors @ %p (phys = %llx)\n",
+		bd_ptr, (unsigned long long)bd_phys);
+
+	/* Allocate space for descriptor status FIFO */
+	sts_size = (bd_num >= TSI721_DMA_MINSTSSZ) ?
+					bd_num : TSI721_DMA_MINSTSSZ;
+	sts_size = roundup_pow_of_two(sts_size);
+	sts_ptr = dma_zalloc_coherent(dev,
+				     sts_size * sizeof(struct tsi721_dma_sts),
+				     &sts_phys, GFP_KERNEL);
+	if (!sts_ptr) {
+		/* Free space allocated for DMA descriptors */
+		dma_free_coherent(dev,
+				  bd_num * sizeof(struct tsi721_dma_desc),
+				  bd_ptr, bd_phys);
+		bdma_chan->bd_base = NULL;
+		return -ENOMEM;
+	}
+
+	bdma_chan->sts_phys = sts_phys;
+	bdma_chan->sts_base = sts_ptr;
+	bdma_chan->sts_size = sts_size;
+
+	dev_dbg(dev,
+		"desc status FIFO @ %p (phys = %llx) size=0x%x\n",
+		sts_ptr, (unsigned long long)sts_phys, sts_size);
+
+	/* Initialize DMA descriptors ring */
+	bd_ptr[bd_num - 1].type_id = cpu_to_le32(DTYPE3 << 29);
+	bd_ptr[bd_num - 1].next_lo = cpu_to_le32((u64)bd_phys &
+						 TSI721_DMAC_DPTRL_MASK);
+	bd_ptr[bd_num - 1].next_hi = cpu_to_le32((u64)bd_phys >> 32);
+
+	/* Setup DMA descriptor pointers */
+	iowrite32(((u64)bd_phys >> 32),
+		bdma_chan->regs + TSI721_DMAC_DPTRH);
+	iowrite32(((u64)bd_phys & TSI721_DMAC_DPTRL_MASK),
+		bdma_chan->regs + TSI721_DMAC_DPTRL);
+
+	/* Setup descriptor status FIFO */
+	iowrite32(((u64)sts_phys >> 32),
+		bdma_chan->regs + TSI721_DMAC_DSBH);
+	iowrite32(((u64)sts_phys & TSI721_DMAC_DSBL_MASK),
+		bdma_chan->regs + TSI721_DMAC_DSBL);
+	iowrite32(TSI721_DMAC_DSSZ_SIZE(sts_size),
+		bdma_chan->regs + TSI721_DMAC_DSSZ);
+
+	/* Clear interrupt bits */
+	iowrite32(TSI721_DMAC_INT_ALL,
+		bdma_chan->regs + TSI721_DMAC_INT);
+
+	ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+
+	/* Toggle DMA channel initialization */
+	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
+	ioread32(bdma_chan->regs + TSI721_DMAC_CTL);
+	bdma_chan->wr_count = bdma_chan->wr_count_next = 0;
+	bdma_chan->sts_rdptr = 0;
+	udelay(10);
+
+	return 0;
+}
+
+static int tsi721_bdma_ch_free(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 ch_stat;
+
+	if (bdma_chan->bd_base == NULL)
+		return 0;
+
+	/* Check if DMA channel still running */
+	ch_stat = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+	if (ch_stat & TSI721_DMAC_STS_RUN)
+		return -EFAULT;
+
+	/* Put DMA channel into init state */
+	iowrite32(TSI721_DMAC_CTL_INIT,	bdma_chan->regs + TSI721_DMAC_CTL);
+
+	/* Free space allocated for DMA descriptors */
+	dma_free_coherent(bdma_chan->dchan.device->dev,
+		bdma_chan->bd_num * sizeof(struct tsi721_dma_desc),
+		bdma_chan->bd_base, bdma_chan->bd_phys);
+	bdma_chan->bd_base = NULL;
+
+	/* Free space allocated for status FIFO */
+	dma_free_coherent(bdma_chan->dchan.device->dev,
+		bdma_chan->sts_size * sizeof(struct tsi721_dma_sts),
+		bdma_chan->sts_base, bdma_chan->sts_phys);
+	bdma_chan->sts_base = NULL;
+	return 0;
+}
+
+static void
+tsi721_bdma_interrupt_enable(struct tsi721_bdma_chan *bdma_chan, int enable)
+{
+	if (enable) {
+		/* Clear pending BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INT);
+		ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+		/* Enable BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INTE);
+	} else {
+		/* Disable BDMA channel interrupts */
+		iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
+		/* Clear pending BDMA channel interrupts */
+		iowrite32(TSI721_DMAC_INT_ALL,
+			bdma_chan->regs + TSI721_DMAC_INT);
+	}
+
+}
+
+static bool tsi721_dma_is_idle(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 sts;
+
+	sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+	return ((sts & TSI721_DMAC_STS_RUN) == 0);
+}
+
+void tsi721_bdma_handler(struct tsi721_bdma_chan *bdma_chan)
+{
+	/* Disable BDMA channel interrupts */
+	iowrite32(0, bdma_chan->regs + TSI721_DMAC_INTE);
+
+	tasklet_schedule(&bdma_chan->tasklet);
+}
+
+#ifdef CONFIG_PCI_MSI
+/**
+ * tsi721_omsg_msix - MSI-X interrupt handler for BDMA channels
+ * @irq: Linux interrupt number
+ * @ptr: Pointer to interrupt-specific data (BDMA channel structure)
+ *
+ * Handles BDMA channel interrupts signaled using MSI-X.
+ */
+static irqreturn_t tsi721_bdma_msix(int irq, void *ptr)
+{
+	struct tsi721_bdma_chan *bdma_chan = ptr;
+
+	tsi721_bdma_handler(bdma_chan);
+	return IRQ_HANDLED;
+}
+#endif /* CONFIG_PCI_MSI */
+
+/* Must be called with the spinlock held */
+static void tsi721_start_dma(struct tsi721_bdma_chan *bdma_chan)
+{
+	if (!tsi721_dma_is_idle(bdma_chan)) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"BUG: Attempt to start non-idle channel\n");
+		return;
+	}
+
+	if (bdma_chan->wr_count == bdma_chan->wr_count_next) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"BUG: Attempt to start DMA with no BDs ready\n");
+		return;
+	}
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"tx_chan: %p, chan: %d, regs: %p\n",
+		bdma_chan, bdma_chan->dchan.chan_id, bdma_chan->regs);
+
+	iowrite32(bdma_chan->wr_count_next,
+		bdma_chan->regs + TSI721_DMAC_DWRCNT);
+	ioread32(bdma_chan->regs + TSI721_DMAC_DWRCNT);
+
+	bdma_chan->wr_count = bdma_chan->wr_count_next;
+}
+
+static void tsi721_desc_put(struct tsi721_bdma_chan *bdma_chan,
+			    struct tsi721_tx_desc *desc)
+{
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"Put desc: %p into free list\n", desc);
+
+	if (desc) {
+		spin_lock_bh(&bdma_chan->lock);
+		list_splice_init(&desc->tx_list, &bdma_chan->free_list);
+		list_add(&desc->desc_node, &bdma_chan->free_list);
+		bdma_chan->wr_count_next = bdma_chan->wr_count;
+		spin_unlock_bh(&bdma_chan->lock);
+	}
+}
+
+static
+struct tsi721_tx_desc *tsi721_desc_get(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_tx_desc *tx_desc, *_tx_desc;
+	struct tsi721_tx_desc *ret = NULL;
+	int i;
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_for_each_entry_safe(tx_desc, _tx_desc,
+				 &bdma_chan->free_list, desc_node) {
+		if (async_tx_test_ack(&tx_desc->txd)) {
+			list_del(&tx_desc->desc_node);
+			ret = tx_desc;
+			break;
+		}
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"desc %p not ACKed\n", tx_desc);
+	}
+
+	i = bdma_chan->wr_count_next % bdma_chan->bd_num;
+	if (i == bdma_chan->bd_num - 1) {
+		i = 0;
+		bdma_chan->wr_count_next++; /* skip link descriptor */
+	}
+
+	bdma_chan->wr_count_next++;
+	tx_desc->txd.phys = bdma_chan->bd_phys +
+				i * sizeof(struct tsi721_dma_desc);
+	tx_desc->hw_desc = &((struct tsi721_dma_desc *)bdma_chan->bd_base)[i];
+
+	spin_unlock_bh(&bdma_chan->lock);
+
+	return ret;
+}
+
+static int
+tsi721_fill_desc(struct tsi721_bdma_chan *bdma_chan,
+	struct tsi721_tx_desc *desc, struct scatterlist *sg,
+	enum dma_rtype rtype, u32 sys_size)
+{
+	struct tsi721_dma_desc *bd_ptr = desc->hw_desc;
+	u64 rio_addr;
+
+	if (sg_dma_len(sg) > TSI721_DMAD_BCOUNT1 + 1) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"SG element is too large\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"desc: 0x%llx, addr: 0x%llx len: 0x%x\n",
+		(u64)desc->txd.phys, (unsigned long long)sg_dma_address(sg),
+		sg_dma_len(sg));
+
+	dev_dbg(bdma_chan->dchan.device->dev,
+		"bd_ptr = %p did=%d raddr=0x%llx\n",
+		bd_ptr, desc->destid, desc->rio_addr);
+
+	/* Initialize DMA descriptor */
+	bd_ptr->type_id = cpu_to_le32((DTYPE1 << 29) |
+					(rtype << 19) | desc->destid);
+	if (desc->interrupt)
+		bd_ptr->type_id |= cpu_to_le32(TSI721_DMAD_IOF);
+	bd_ptr->bcount = cpu_to_le32(((desc->rio_addr & 0x3) << 30) |
+					(sys_size << 26) | sg_dma_len(sg));
+	rio_addr = (desc->rio_addr >> 2) |
+				((u64)(desc->rio_addr_u & 0x3) << 62);
+	bd_ptr->raddr_lo = cpu_to_le32(rio_addr & 0xffffffff);
+	bd_ptr->raddr_hi = cpu_to_le32(rio_addr >> 32);
+	bd_ptr->t1.bufptr_lo = cpu_to_le32(
+					(u64)sg_dma_address(sg) & 0xffffffff);
+	bd_ptr->t1.bufptr_hi = cpu_to_le32((u64)sg_dma_address(sg) >> 32);
+	bd_ptr->t1.s_dist = 0;
+	bd_ptr->t1.s_size = 0;
+
+	return 0;
+}
+
+static void tsi721_dma_chain_complete(struct tsi721_bdma_chan *bdma_chan,
+				      struct tsi721_tx_desc *desc)
+{
+	struct dma_async_tx_descriptor *txd = &desc->txd;
+	dma_async_tx_callback callback = txd->callback;
+	void *param = txd->callback_param;
+
+	list_splice_init(&desc->tx_list, &bdma_chan->free_list);
+	list_move(&desc->desc_node, &bdma_chan->free_list);
+	bdma_chan->completed_cookie = txd->cookie;
+
+	if (callback)
+		callback(param);
+}
+
+static void tsi721_dma_complete_all(struct tsi721_bdma_chan *bdma_chan)
+{
+	struct tsi721_tx_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	BUG_ON(!tsi721_dma_is_idle(bdma_chan));
+
+	if (!list_empty(&bdma_chan->queue))
+		tsi721_start_dma(bdma_chan);
+
+	list_splice_init(&bdma_chan->active_list, &list);
+	list_splice_init(&bdma_chan->queue, &bdma_chan->active_list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		tsi721_dma_chain_complete(bdma_chan, desc);
+}
+
+static void tsi721_clr_stat(struct tsi721_bdma_chan *bdma_chan)
+{
+	u32 srd_ptr;
+	u64 *sts_ptr;
+	int i, j;
+
+	/* Check and clear descriptor status FIFO entries */
+	srd_ptr = bdma_chan->sts_rdptr;
+	sts_ptr = bdma_chan->sts_base;
+	j = srd_ptr * 8;
+	while (sts_ptr[j]) {
+		for (i = 0; i < 8 && sts_ptr[j]; i++, j++)
+			sts_ptr[j] = 0;
+
+		++srd_ptr;
+		srd_ptr %= bdma_chan->sts_size;
+		j = srd_ptr * 8;
+	}
+
+	iowrite32(srd_ptr, bdma_chan->regs + TSI721_DMAC_DSRP);
+	bdma_chan->sts_rdptr = srd_ptr;
+}
+
+static void tsi721_advance_work(struct tsi721_bdma_chan *bdma_chan)
+{
+	if (list_empty(&bdma_chan->active_list) ||
+		list_is_singular(&bdma_chan->active_list)) {
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"%s: Active_list empty\n", __func__);
+		tsi721_dma_complete_all(bdma_chan);
+	} else {
+		dev_dbg(bdma_chan->dchan.device->dev,
+			"%s: Active_list NOT empty\n", __func__);
+		tsi721_dma_chain_complete(bdma_chan,
+					tsi721_dma_first_active(bdma_chan));
+		tsi721_start_dma(bdma_chan);
+	}
+}
+
+static void tsi721_dma_tasklet(unsigned long data)
+{
+	struct tsi721_bdma_chan *bdma_chan = (struct tsi721_bdma_chan *)data;
+	u32 dmac_int, dmac_sts;
+
+	dmac_int = ioread32(bdma_chan->regs + TSI721_DMAC_INT);
+	dev_dbg(bdma_chan->dchan.device->dev, "%s: DMAC%d_INT = 0x%x\n",
+		__func__, bdma_chan->id, dmac_int);
+	/* Clear channel interrupts */
+	iowrite32(dmac_int, bdma_chan->regs + TSI721_DMAC_INT);
+
+	if (dmac_int & TSI721_DMAC_INT_ERR) {
+		dmac_sts = ioread32(bdma_chan->regs + TSI721_DMAC_STS);
+		dev_err(bdma_chan->dchan.device->dev,
+			"%s: DMA ERROR - DMAC%d_STS = 0x%x\n",
+			__func__, bdma_chan->id, dmac_sts);
+	}
+
+	if (dmac_int & TSI721_DMAC_INT_STFULL) {
+		dev_err(bdma_chan->dchan.device->dev,
+			"%s: DMAC%d descriptor status FIFO is full\n",
+			__func__, bdma_chan->id);
+	}
+
+	if (dmac_int & (TSI721_DMAC_INT_DONE | TSI721_DMAC_INT_IOFDONE)) {
+		tsi721_clr_stat(bdma_chan);
+		spin_lock(&bdma_chan->lock);
+		tsi721_advance_work(bdma_chan);
+		spin_unlock(&bdma_chan->lock);
+	}
+
+	/* Re-Enable BDMA channel interrupts */
+	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
+}
+
+static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
+{
+	struct tsi721_tx_desc *desc = to_tsi721_desc(txd);
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(txd->chan);
+	dma_cookie_t cookie;
+
+	spin_lock_bh(&bdma_chan->lock);
+
+	cookie = txd->chan->cookie;
+	if (++cookie < 0)
+		cookie = 1;
+	txd->chan->cookie = cookie;
+	txd->cookie = cookie;
+
+	if (list_empty(&bdma_chan->active_list)) {
+		list_add_tail(&desc->desc_node, &bdma_chan->active_list);
+		tsi721_start_dma(bdma_chan);
+	} else {
+		list_add_tail(&desc->desc_node, &bdma_chan->queue);
+	}
+
+	spin_unlock_bh(&bdma_chan->lock);
+	return cookie;
+}
+
+static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+#ifdef CONFIG_PCI_MSI
+	struct tsi721_device *priv = to_tsi721(dchan->device);
+#endif
+	struct tsi721_tx_desc *desc = NULL;
+	LIST_HEAD(tmp_list);
+	int i;
+	int rc;
+
+	if (bdma_chan->bd_base)
+		return bdma_chan->bd_num - 1;
+
+	/* Initialize BDMA channel */
+	if (tsi721_bdma_ch_init(bdma_chan)) {
+		dev_err(dchan->device->dev, "Unable to initialize data DMA"
+			" channel %d, aborting\n", bdma_chan->id);
+		return -ENOMEM;
+	}
+
+	/* Alocate matching number of logical descriptors */
+	desc = kcalloc((bdma_chan->bd_num - 1), sizeof(struct tsi721_tx_desc),
+			GFP_KERNEL);
+	if (!desc) {
+		dev_err(dchan->device->dev,
+			"Failed to allocate logical descriptors\n");
+		rc = -ENOMEM;
+		goto err_out;
+	}
+
+	bdma_chan->tx_desc = desc;
+
+	for (i = 0; i < bdma_chan->bd_num - 1; i++) {
+		dma_async_tx_descriptor_init(&desc[i].txd, dchan);
+		desc[i].txd.tx_submit = tsi721_tx_submit;
+		desc[i].txd.flags = DMA_CTRL_ACK;
+		INIT_LIST_HEAD(&desc[i].tx_list);
+		list_add_tail(&desc[i].desc_node, &tmp_list);
+	}
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_splice(&tmp_list, &bdma_chan->free_list);
+	bdma_chan->completed_cookie = dchan->cookie = 1;
+	spin_unlock_bh(&bdma_chan->lock);
+
+#ifdef CONFIG_PCI_MSI
+	if (priv->flags & TSI721_USING_MSIX) {
+		/* Request interrupt service if we are in MSI-X mode */
+		rc = request_irq(
+			priv->msix[TSI721_VECT_DMA0_DONE +
+				   bdma_chan->id].vector,
+			tsi721_bdma_msix, 0,
+			priv->msix[TSI721_VECT_DMA0_DONE +
+				   bdma_chan->id].irq_name,
+			(void *)bdma_chan);
+
+		if (rc) {
+			dev_dbg(dchan->device->dev,
+				"Unable to allocate MSI-X interrupt for "
+				"BDMA%d-DONE\n", bdma_chan->id);
+			goto err_out;
+		}
+
+		rc = request_irq(priv->msix[TSI721_VECT_DMA0_INT +
+					    bdma_chan->id].vector,
+				tsi721_bdma_msix, 0,
+				priv->msix[TSI721_VECT_DMA0_INT +
+					   bdma_chan->id].irq_name,
+				(void *)bdma_chan);
+
+		if (rc)	{
+			dev_dbg(dchan->device->dev,
+				"Unable to allocate MSI-X interrupt for "
+				"BDMA%d-INT\n", bdma_chan->id);
+			free_irq(
+				priv->msix[TSI721_VECT_DMA0_DONE +
+					   bdma_chan->id].vector,
+				(void *)bdma_chan);
+			rc = -EIO;
+			goto err_out;
+		}
+	}
+#endif /* CONFIG_PCI_MSI */
+
+	tasklet_enable(&bdma_chan->tasklet);
+	tsi721_bdma_interrupt_enable(bdma_chan, 1);
+
+	return bdma_chan->bd_num - 1;
+
+err_out:
+	kfree(desc);
+	tsi721_bdma_ch_free(bdma_chan);
+	return rc;
+}
+
+static void tsi721_free_chan_resources(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+#ifdef CONFIG_PCI_MSI
+	struct tsi721_device *priv = to_tsi721(dchan->device);
+#endif
+	LIST_HEAD(list);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (bdma_chan->bd_base == NULL)
+		return;
+
+	BUG_ON(!list_empty(&bdma_chan->active_list));
+	BUG_ON(!list_empty(&bdma_chan->queue));
+
+	tasklet_disable(&bdma_chan->tasklet);
+
+	spin_lock_bh(&bdma_chan->lock);
+	list_splice_init(&bdma_chan->free_list, &list);
+	spin_unlock_bh(&bdma_chan->lock);
+
+	tsi721_bdma_interrupt_enable(bdma_chan, 0);
+
+#ifdef CONFIG_PCI_MSI
+	if (priv->flags & TSI721_USING_MSIX) {
+		free_irq(priv->msix[TSI721_VECT_DMA0_DONE +
+				    bdma_chan->id].vector, (void *)bdma_chan);
+		free_irq(priv->msix[TSI721_VECT_DMA0_INT +
+				    bdma_chan->id].vector, (void *)bdma_chan);
+	}
+#endif /* CONFIG_PCI_MSI */
+
+	tsi721_bdma_ch_free(bdma_chan);
+	kfree(bdma_chan->tx_desc);
+}
+
+static
+enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
+				 struct dma_tx_state *txstate)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	dma_cookie_t		last_used;
+	dma_cookie_t		last_completed;
+	int			ret;
+
+	spin_lock_bh(&bdma_chan->lock);
+	last_completed = bdma_chan->completed_cookie;
+	last_used = dchan->cookie;
+	spin_unlock_bh(&bdma_chan->lock);
+
+	ret = dma_async_is_complete(cookie, last_completed, last_used);
+
+	dma_set_tx_state(txstate, last_completed, last_used, 0);
+
+	dev_dbg(dchan->device->dev,
+		"%s: exit, ret: %d, last_completed: %d, last_used: %d\n",
+		__func__, ret, last_completed, last_used);
+
+	return ret;
+}
+
+static void tsi721_issue_pending(struct dma_chan *dchan)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (tsi721_dma_is_idle(bdma_chan)) {
+		spin_lock_bh(&bdma_chan->lock);
+		tsi721_advance_work(bdma_chan);
+		spin_unlock_bh(&bdma_chan->lock);
+	} else
+		dev_dbg(dchan->device->dev,
+			"%s: DMA channel still busy\n", __func__);
+}
+
+static
+struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
+			struct scatterlist *sgl, unsigned int sg_len,
+			enum dma_transfer_direction dir, unsigned long flags,
+			void *tinfo)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	struct tsi721_tx_desc *desc = NULL;
+	struct tsi721_tx_desc *first = NULL;
+	struct scatterlist *sg;
+	struct rio_dma_ext *rext = tinfo;
+	u64 rio_addr = rext->rio_addr; /* limited to 64-bit rio_addr for now */
+	unsigned int i;
+	u32 sys_size = dma_to_mport(dchan->device)->sys_size;
+	enum dma_rtype rtype;
+
+	if (!sgl || !sg_len) {
+		dev_err(dchan->device->dev, "%s: No SG list\n", __func__);
+		return NULL;
+	}
+
+	if (dir == DMA_DEV_TO_MEM)
+		rtype = NREAD;
+	else if (dir == DMA_MEM_TO_DEV) {
+		switch (rext->wr_type) {
+		case RDW_ALL_NWRITE:
+			rtype = ALL_NWRITE;
+			break;
+		case RDW_ALL_NWRITE_R:
+			rtype = ALL_NWRITE_R;
+			break;
+		case RDW_LAST_NWRITE_R:
+		default:
+			rtype = LAST_NWRITE_R;
+			break;
+		}
+	} else {
+		dev_err(dchan->device->dev,
+			"%s: Unsupported DMA direction option\n", __func__);
+		return NULL;
+	}
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		int err;
+
+		dev_dbg(dchan->device->dev, "%s: sg #%d\n", __func__, i);
+		desc = tsi721_desc_get(bdma_chan);
+		if (!desc) {
+			dev_err(dchan->device->dev,
+				"Not enough descriptors available\n");
+			goto err_desc_get;
+		}
+
+		if (sg_is_last(sg))
+			desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
+		else
+			desc->interrupt = false;
+
+		desc->destid = rext->destid;
+		desc->rio_addr = rio_addr;
+		desc->rio_addr_u = 0;
+
+		err = tsi721_fill_desc(bdma_chan, desc, sg, rtype, sys_size);
+		if (err) {
+			dev_err(dchan->device->dev,
+				"Failed to build desc: %d\n", err);
+			goto err_desc_get;
+		}
+
+		rio_addr += sg_dma_len(sg);
+
+		if (!first)
+			first = desc;
+		else
+			list_add_tail(&desc->desc_node, &first->tx_list);
+	}
+
+	first->txd.cookie = -EBUSY;
+	desc->txd.flags = flags;
+
+	return &first->txd;
+
+err_desc_get:
+	tsi721_desc_put(bdma_chan, first);
+	return NULL;
+}
+
+static int tsi721_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
+			     unsigned long arg)
+{
+	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
+	struct tsi721_tx_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	dev_dbg(dchan->device->dev, "%s: Entry\n", __func__);
+
+	if (cmd != DMA_TERMINATE_ALL)
+		return -ENXIO;
+
+	spin_lock_bh(&bdma_chan->lock);
+
+	/* make sure to stop the transfer */
+	iowrite32(TSI721_DMAC_CTL_SUSP, bdma_chan->regs + TSI721_DMAC_CTL);
+
+	list_splice_init(&bdma_chan->active_list, &list);
+	list_splice_init(&bdma_chan->queue, &list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		tsi721_dma_chain_complete(bdma_chan, desc);
+
+	spin_unlock_bh(&bdma_chan->lock);
+
+	return 0;
+}
+
+int __devinit tsi721_register_dma(struct tsi721_device *priv)
+{
+	int i;
+	int nr_channels = TSI721_DMA_MAXCH;
+	int err;
+	struct rio_mport *mport = priv->mport;
+
+	mport->dma.dev = &priv->pdev->dev;
+	mport->dma.chancnt = nr_channels;
+
+	INIT_LIST_HEAD(&mport->dma.channels);
+
+	for (i = 0; i < nr_channels; i++) {
+		struct tsi721_bdma_chan *bdma_chan = &priv->bdma[i];
+
+		if (i == TSI721_DMACH_MAINT)
+			continue;
+
+		bdma_chan->bd_num = 64;
+		bdma_chan->regs = priv->regs + TSI721_DMAC_BASE(i);
+
+		bdma_chan->dchan.device = &mport->dma;
+		bdma_chan->dchan.cookie = 1;
+		bdma_chan->dchan.chan_id = i;
+		bdma_chan->id = i;
+
+		spin_lock_init(&bdma_chan->lock);
+
+		INIT_LIST_HEAD(&bdma_chan->active_list);
+		INIT_LIST_HEAD(&bdma_chan->queue);
+		INIT_LIST_HEAD(&bdma_chan->free_list);
+
+		tasklet_init(&bdma_chan->tasklet, tsi721_dma_tasklet,
+			     (unsigned long)bdma_chan);
+		tasklet_disable(&bdma_chan->tasklet);
+		list_add_tail(&bdma_chan->dchan.device_node,
+			      &mport->dma.channels);
+	}
+
+	dma_cap_zero(mport->dma.cap_mask);
+	dma_cap_set(DMA_PRIVATE, mport->dma.cap_mask);
+	dma_cap_set(DMA_SLAVE, mport->dma.cap_mask);
+
+	mport->dma.device_alloc_chan_resources = tsi721_alloc_chan_resources;
+	mport->dma.device_free_chan_resources = tsi721_free_chan_resources;
+	mport->dma.device_tx_status = tsi721_tx_status;
+	mport->dma.device_issue_pending = tsi721_issue_pending;
+	mport->dma.device_prep_slave_sg = tsi721_prep_rio_sg;
+	mport->dma.device_control = tsi721_device_control;
+
+	err = dma_async_device_register(&mport->dma);
+	if (err)
+		dev_err(&priv->pdev->dev, "Failed to register DMA device\n");
+
+	return err;
+}