1 files changed, 0 insertions, 627 deletions

diff --git a/target/linux/ramips/patches-3.18/0054-DMA-ralink-add-rt2880-dma-engine.patch b/target/linux/ramips/patches-3.18/0054-DMA-ralink-add-rt2880-dma-engine.patch
deleted file mode 100644
index fa0f42f108..0000000000
--- a/target/linux/ramips/patches-3.18/0054-DMA-ralink-add-rt2880-dma-engine.patch
+++ /dev/null
@@ -1,627 +0,0 @@
-From cf93418a4bd5e69f069a65da92537bd4d6191223 Mon Sep 17 00:00:00 2001
-From: John Crispin <blogic@openwrt.org>
-Date: Sun, 27 Jul 2014 09:29:51 +0100
-Subject: [PATCH 54/57] DMA: ralink: add rt2880 dma engine
-
-Signed-off-by: John Crispin <blogic@openwrt.org>
----
- drivers/dma/Kconfig       |    6 +
- drivers/dma/Makefile      |    1 +
- drivers/dma/dmaengine.c   |   26 ++
- drivers/dma/ralink-gdma.c |  577 +++++++++++++++++++++++++++++++++++++++++++++
- include/linux/dmaengine.h |    1 +
- 5 files changed, 611 insertions(+)
- create mode 100644 drivers/dma/ralink-gdma.c
-
---- a/drivers/dma/Kconfig
-+++ b/drivers/dma/Kconfig
-@@ -409,6 +409,12 @@ config NBPFAXI_DMA
- 	help
- 	  Support for "Type-AXI" NBPF DMA IPs from Renesas
- 
-+config DMA_RALINK
-+	tristate "RALINK DMA support"
-+	depends on RALINK && SOC_MT7620
-+	select DMA_ENGINE
-+	select DMA_VIRTUAL_CHANNELS
-+
- config DMA_ENGINE
- 	bool
- 
---- a/drivers/dma/Makefile
-+++ b/drivers/dma/Makefile
-@@ -49,3 +49,4 @@ obj-y += xilinx/
- obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
- obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
- obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
-+obj-$(CONFIG_DMA_RALINK) += ralink-gdma.o
---- /dev/null
-+++ b/drivers/dma/ralink-gdma.c
-@@ -0,0 +1,577 @@
-+/*
-+ *  Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de>
-+ *  GDMA4740 DMAC support
-+ *
-+ *  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.
-+ *
-+ *  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.,
-+ *  675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ */
-+
-+#include <linux/dmaengine.h>
-+#include <linux/dma-mapping.h>
-+#include <linux/err.h>
-+#include <linux/init.h>
-+#include <linux/list.h>
-+#include <linux/module.h>
-+#include <linux/platform_device.h>
-+#include <linux/slab.h>
-+#include <linux/spinlock.h>
-+#include <linux/irq.h>
-+#include <linux/of_dma.h>
-+
-+#include "virt-dma.h"
-+
-+#define GDMA_NR_CHANS			16
-+
-+#define GDMA_REG_SRC_ADDR(x)		(0x00 + (x) * 0x10)
-+#define GDMA_REG_DST_ADDR(x)		(0x04 + (x) * 0x10)
-+
-+#define GDMA_REG_CTRL0(x)		(0x08 + (x) * 0x10)
-+#define GDMA_REG_CTRL0_TX_MASK		0xffff
-+#define GDMA_REG_CTRL0_TX_SHIFT		16
-+#define GDMA_REG_CTRL0_CURR_MASK	0xff
-+#define GDMA_REG_CTRL0_CURR_SHIFT	8
-+#define	GDMA_REG_CTRL0_SRC_ADDR_FIXED	BIT(7)
-+#define GDMA_REG_CTRL0_DST_ADDR_FIXED	BIT(6)
-+#define GDMA_REG_CTRL0_BURST_MASK	0x7
-+#define GDMA_REG_CTRL0_BURST_SHIFT	3
-+#define	GDMA_REG_CTRL0_DONE_INT		BIT(2)
-+#define	GDMA_REG_CTRL0_ENABLE		BIT(1)
-+#define	GDMA_REG_CTRL0_HW_MODE		0
-+
-+#define GDMA_REG_CTRL1(x)		(0x0c + (x) * 0x10)
-+#define GDMA_REG_CTRL1_SEG_MASK		0xf
-+#define GDMA_REG_CTRL1_SEG_SHIFT	22
-+#define GDMA_REG_CTRL1_REQ_MASK		0x3f
-+#define GDMA_REG_CTRL1_SRC_REQ_SHIFT	16
-+#define GDMA_REG_CTRL1_DST_REQ_SHIFT	8
-+#define GDMA_REG_CTRL1_CONTINOUS	BIT(14)
-+#define GDMA_REG_CTRL1_NEXT_MASK	0x1f
-+#define GDMA_REG_CTRL1_NEXT_SHIFT	3
-+#define GDMA_REG_CTRL1_COHERENT		BIT(2)
-+#define GDMA_REG_CTRL1_FAIL		BIT(1)
-+#define GDMA_REG_CTRL1_MASK		BIT(0)
-+
-+#define GDMA_REG_UNMASK_INT		0x200
-+#define GDMA_REG_DONE_INT		0x204
-+
-+#define GDMA_REG_GCT			0x220
-+#define GDMA_REG_GCT_CHAN_MASK		0x3
-+#define GDMA_REG_GCT_CHAN_SHIFT		3
-+#define GDMA_REG_GCT_VER_MASK		0x3
-+#define GDMA_REG_GCT_VER_SHIFT		1
-+#define GDMA_REG_GCT_ARBIT_RR		BIT(0)
-+
-+enum gdma_dma_transfer_size {
-+	GDMA_TRANSFER_SIZE_4BYTE	= 0,
-+	GDMA_TRANSFER_SIZE_8BYTE	= 1,
-+	GDMA_TRANSFER_SIZE_16BYTE	= 2,
-+	GDMA_TRANSFER_SIZE_32BYTE	= 3,
-+};
-+
-+struct gdma_dma_sg {
-+	dma_addr_t addr;
-+	unsigned int len;
-+};
-+
-+struct gdma_dma_desc {
-+	struct virt_dma_desc vdesc;
-+
-+	enum dma_transfer_direction direction;
-+	bool cyclic;
-+
-+	unsigned int num_sgs;
-+	struct gdma_dma_sg sg[];
-+};
-+
-+struct gdma_dmaengine_chan {
-+	struct virt_dma_chan vchan;
-+	unsigned int id;
-+
-+	dma_addr_t fifo_addr;
-+	unsigned int transfer_shift;
-+
-+	struct gdma_dma_desc *desc;
-+	unsigned int next_sg;
-+};
-+
-+struct gdma_dma_dev {
-+	struct dma_device ddev;
-+	void __iomem *base;
-+	struct clk *clk;
-+
-+	struct gdma_dmaengine_chan chan[GDMA_NR_CHANS];
-+};
-+
-+static struct gdma_dma_dev *gdma_dma_chan_get_dev(
-+	struct gdma_dmaengine_chan *chan)
-+{
-+	return container_of(chan->vchan.chan.device, struct gdma_dma_dev,
-+		ddev);
-+}
-+
-+static struct gdma_dmaengine_chan *to_gdma_dma_chan(struct dma_chan *c)
-+{
-+	return container_of(c, struct gdma_dmaengine_chan, vchan.chan);
-+}
-+
-+static struct gdma_dma_desc *to_gdma_dma_desc(struct virt_dma_desc *vdesc)
-+{
-+	return container_of(vdesc, struct gdma_dma_desc, vdesc);
-+}
-+
-+static inline uint32_t gdma_dma_read(struct gdma_dma_dev *dma_dev,
-+	unsigned int reg)
-+{
-+	return readl(dma_dev->base + reg);
-+}
-+
-+static inline void gdma_dma_write(struct gdma_dma_dev *dma_dev,
-+	unsigned reg, uint32_t val)
-+{
-+	//printk("gdma --> %p = 0x%08X\n", dma_dev->base + reg, val);
-+	writel(val, dma_dev->base + reg);
-+}
-+
-+static inline void gdma_dma_write_mask(struct gdma_dma_dev *dma_dev,
-+	unsigned int reg, uint32_t val, uint32_t mask)
-+{
-+	uint32_t tmp;
-+
-+	tmp = gdma_dma_read(dma_dev, reg);
-+	tmp &= ~mask;
-+	tmp |= val;
-+	gdma_dma_write(dma_dev, reg, tmp);
-+}
-+
-+static struct gdma_dma_desc *gdma_dma_alloc_desc(unsigned int num_sgs)
-+{
-+	return kzalloc(sizeof(struct gdma_dma_desc) +
-+		sizeof(struct gdma_dma_sg) * num_sgs, GFP_ATOMIC);
-+}
-+
-+static enum gdma_dma_transfer_size gdma_dma_maxburst(u32 maxburst)
-+{
-+	if (maxburst <= 7)
-+		return GDMA_TRANSFER_SIZE_4BYTE;
-+	else if (maxburst <= 15)
-+		return GDMA_TRANSFER_SIZE_8BYTE;
-+	else if (maxburst <= 31)
-+		return GDMA_TRANSFER_SIZE_16BYTE;
-+
-+	return GDMA_TRANSFER_SIZE_32BYTE;
-+}
-+
-+static int gdma_dma_slave_config(struct dma_chan *c,
-+	const struct dma_slave_config *config)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
-+	enum gdma_dma_transfer_size transfer_size;
-+	uint32_t flags;
-+	uint32_t ctrl0, ctrl1;
-+
-+	switch (config->direction) {
-+	case DMA_MEM_TO_DEV:
-+		ctrl1 = 32 << GDMA_REG_CTRL1_SRC_REQ_SHIFT;
-+		ctrl1 |= config->slave_id << GDMA_REG_CTRL1_DST_REQ_SHIFT;
-+		flags = GDMA_REG_CTRL0_DST_ADDR_FIXED;
-+		transfer_size = gdma_dma_maxburst(config->dst_maxburst);
-+		chan->fifo_addr = config->dst_addr;
-+		break;
-+
-+	case DMA_DEV_TO_MEM:
-+		ctrl1 = config->slave_id << GDMA_REG_CTRL1_SRC_REQ_SHIFT;
-+		ctrl1 |= 32 << GDMA_REG_CTRL1_DST_REQ_SHIFT;
-+		flags = GDMA_REG_CTRL0_SRC_ADDR_FIXED;
-+		transfer_size = gdma_dma_maxburst(config->src_maxburst);
-+		chan->fifo_addr = config->src_addr;
-+		break;
-+
-+	default:
-+		return -EINVAL;
-+	}
-+
-+	chan->transfer_shift = 1 + transfer_size;
-+
-+	ctrl0 = flags | GDMA_REG_CTRL0_HW_MODE;
-+	ctrl0 |= GDMA_REG_CTRL0_DONE_INT;
-+
-+	ctrl1 &= ~(GDMA_REG_CTRL1_NEXT_MASK << GDMA_REG_CTRL1_NEXT_SHIFT);
-+	ctrl1 |= chan->id << GDMA_REG_CTRL1_NEXT_SHIFT;
-+	ctrl1 |= GDMA_REG_CTRL1_FAIL;
-+	ctrl1 &= ~GDMA_REG_CTRL1_CONTINOUS;
-+	gdma_dma_write(dma_dev, GDMA_REG_CTRL0(chan->id), ctrl0);
-+	gdma_dma_write(dma_dev, GDMA_REG_CTRL1(chan->id), ctrl1);
-+
-+	return 0;
-+}
-+
-+static int gdma_dma_terminate_all(struct dma_chan *c)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
-+	unsigned long flags;
-+	LIST_HEAD(head);
-+
-+	spin_lock_irqsave(&chan->vchan.lock, flags);
-+	gdma_dma_write_mask(dma_dev, GDMA_REG_CTRL0(chan->id), 0,
-+			GDMA_REG_CTRL0_ENABLE);
-+	chan->desc = NULL;
-+	vchan_get_all_descriptors(&chan->vchan, &head);
-+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
-+
-+	vchan_dma_desc_free_list(&chan->vchan, &head);
-+
-+	return 0;
-+}
-+
-+static int gdma_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
-+	unsigned long arg)
-+{
-+	struct dma_slave_config *config = (struct dma_slave_config *)arg;
-+
-+	switch (cmd) {
-+	case DMA_SLAVE_CONFIG:
-+		return gdma_dma_slave_config(chan, config);
-+	case DMA_TERMINATE_ALL:
-+		return gdma_dma_terminate_all(chan);
-+	default:
-+		return -ENOSYS;
-+	}
-+}
-+
-+static int gdma_dma_start_transfer(struct gdma_dmaengine_chan *chan)
-+{
-+	struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
-+	dma_addr_t src_addr, dst_addr;
-+	struct virt_dma_desc *vdesc;
-+	struct gdma_dma_sg *sg;
-+
-+	gdma_dma_write_mask(dma_dev, GDMA_REG_CTRL0(chan->id), 0,
-+			GDMA_REG_CTRL0_ENABLE);
-+
-+	if (!chan->desc) {
-+		vdesc = vchan_next_desc(&chan->vchan);
-+		if (!vdesc)
-+			return 0;
-+		chan->desc = to_gdma_dma_desc(vdesc);
-+		chan->next_sg = 0;
-+	}
-+
-+	if (chan->next_sg == chan->desc->num_sgs)
-+		chan->next_sg = 0;
-+
-+	sg = &chan->desc->sg[chan->next_sg];
-+
-+	if (chan->desc->direction == DMA_MEM_TO_DEV) {
-+		src_addr = sg->addr;
-+		dst_addr = chan->fifo_addr;
-+	} else {
-+		src_addr = chan->fifo_addr;
-+		dst_addr = sg->addr;
-+	}
-+	gdma_dma_write(dma_dev, GDMA_REG_SRC_ADDR(chan->id), src_addr);
-+	gdma_dma_write(dma_dev, GDMA_REG_DST_ADDR(chan->id), dst_addr);
-+	gdma_dma_write_mask(dma_dev, GDMA_REG_CTRL0(chan->id),
-+			(sg->len << GDMA_REG_CTRL0_TX_SHIFT) | GDMA_REG_CTRL0_ENABLE,
-+			GDMA_REG_CTRL0_TX_MASK << GDMA_REG_CTRL0_TX_SHIFT);
-+	chan->next_sg++;
-+	gdma_dma_write_mask(dma_dev, GDMA_REG_CTRL1(chan->id), 0, GDMA_REG_CTRL1_MASK);
-+
-+	return 0;
-+}
-+
-+static void gdma_dma_chan_irq(struct gdma_dmaengine_chan *chan)
-+{
-+	spin_lock(&chan->vchan.lock);
-+	if (chan->desc) {
-+		if (chan->desc && chan->desc->cyclic) {
-+			vchan_cyclic_callback(&chan->desc->vdesc);
-+		} else {
-+			if (chan->next_sg == chan->desc->num_sgs) {
-+				chan->desc = NULL;
-+				vchan_cookie_complete(&chan->desc->vdesc);
-+			}
-+		}
-+	}
-+	gdma_dma_start_transfer(chan);
-+	spin_unlock(&chan->vchan.lock);
-+}
-+
-+static irqreturn_t gdma_dma_irq(int irq, void *devid)
-+{
-+	struct gdma_dma_dev *dma_dev = devid;
-+	uint32_t unmask, done;
-+	unsigned int i;
-+
-+	unmask = gdma_dma_read(dma_dev, GDMA_REG_UNMASK_INT);
-+	gdma_dma_write(dma_dev, GDMA_REG_UNMASK_INT, unmask);
-+	done = gdma_dma_read(dma_dev, GDMA_REG_DONE_INT);
-+
-+	for (i = 0; i < GDMA_NR_CHANS; ++i)
-+		if (done & BIT(i))
-+			gdma_dma_chan_irq(&dma_dev->chan[i]);
-+	gdma_dma_write(dma_dev, GDMA_REG_DONE_INT, done);
-+
-+	return IRQ_HANDLED;
-+}
-+
-+static void gdma_dma_issue_pending(struct dma_chan *c)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	unsigned long flags;
-+
-+	spin_lock_irqsave(&chan->vchan.lock, flags);
-+	if (vchan_issue_pending(&chan->vchan) && !chan->desc)
-+		gdma_dma_start_transfer(chan);
-+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
-+}
-+
-+static struct dma_async_tx_descriptor *gdma_dma_prep_slave_sg(
-+	struct dma_chan *c, struct scatterlist *sgl,
-+	unsigned int sg_len, enum dma_transfer_direction direction,
-+	unsigned long flags, void *context)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	struct gdma_dma_desc *desc;
-+	struct scatterlist *sg;
-+	unsigned int i;
-+
-+	desc = gdma_dma_alloc_desc(sg_len);
-+	if (!desc)
-+		return NULL;
-+
-+	for_each_sg(sgl, sg, sg_len, i) {
-+		desc->sg[i].addr = sg_dma_address(sg);
-+		desc->sg[i].len = sg_dma_len(sg);
-+	}
-+
-+	desc->num_sgs = sg_len;
-+	desc->direction = direction;
-+	desc->cyclic = false;
-+
-+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
-+}
-+
-+static struct dma_async_tx_descriptor *gdma_dma_prep_dma_cyclic(
-+	struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
-+	size_t period_len, enum dma_transfer_direction direction,
-+	unsigned long flags, void *context)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	struct gdma_dma_desc *desc;
-+	unsigned int num_periods, i;
-+
-+	if (buf_len % period_len)
-+		return NULL;
-+
-+	num_periods = buf_len / period_len;
-+
-+	desc = gdma_dma_alloc_desc(num_periods);
-+	if (!desc)
-+		return NULL;
-+
-+	for (i = 0; i < num_periods; i++) {
-+		desc->sg[i].addr = buf_addr;
-+		desc->sg[i].len = period_len;
-+		buf_addr += period_len;
-+	}
-+
-+	desc->num_sgs = num_periods;
-+	desc->direction = direction;
-+	desc->cyclic = true;
-+
-+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
-+}
-+
-+static size_t gdma_dma_desc_residue(struct gdma_dmaengine_chan *chan,
-+	struct gdma_dma_desc *desc, unsigned int next_sg)
-+{
-+	struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
-+	unsigned int residue, count;
-+	unsigned int i;
-+
-+	residue = 0;
-+
-+	for (i = next_sg; i < desc->num_sgs; i++)
-+		residue += desc->sg[i].len;
-+
-+	if (next_sg != 0) {
-+		count = gdma_dma_read(dma_dev, GDMA_REG_CTRL0(chan->id));
-+		count >>= GDMA_REG_CTRL0_CURR_SHIFT;
-+		count &= GDMA_REG_CTRL0_CURR_MASK;
-+		residue += count << chan->transfer_shift;
-+	}
-+
-+	return residue;
-+}
-+
-+static enum dma_status gdma_dma_tx_status(struct dma_chan *c,
-+	dma_cookie_t cookie, struct dma_tx_state *state)
-+{
-+	struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
-+	struct virt_dma_desc *vdesc;
-+	enum dma_status status;
-+	unsigned long flags;
-+
-+	status = dma_cookie_status(c, cookie, state);
-+	if (status == DMA_SUCCESS || !state)
-+		return status;
-+
-+	spin_lock_irqsave(&chan->vchan.lock, flags);
-+	vdesc = vchan_find_desc(&chan->vchan, cookie);
-+	if (cookie == chan->desc->vdesc.tx.cookie) {
-+		state->residue = gdma_dma_desc_residue(chan, chan->desc,
-+				chan->next_sg);
-+	} else if (vdesc) {
-+		state->residue = gdma_dma_desc_residue(chan,
-+				to_gdma_dma_desc(vdesc), 0);
-+	} else {
-+		state->residue = 0;
-+	}
-+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
-+
-+	return status;
-+}
-+
-+static int gdma_dma_alloc_chan_resources(struct dma_chan *c)
-+{
-+	return 0;
-+}
-+
-+static void gdma_dma_free_chan_resources(struct dma_chan *c)
-+{
-+	vchan_free_chan_resources(to_virt_chan(c));
-+}
-+
-+static void gdma_dma_desc_free(struct virt_dma_desc *vdesc)
-+{
-+	kfree(container_of(vdesc, struct gdma_dma_desc, vdesc));
-+}
-+
-+static struct dma_chan *
-+of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
-+			struct of_dma *ofdma)
-+{
-+	struct gdma_dma_dev *dma_dev = ofdma->of_dma_data;
-+	unsigned int request = dma_spec->args[0];
-+
-+	if (request >= GDMA_NR_CHANS)
-+		return NULL;
-+
-+	return dma_get_slave_channel(&(dma_dev->chan[request].vchan.chan));
-+}
-+
-+static int gdma_dma_probe(struct platform_device *pdev)
-+{
-+	struct gdma_dmaengine_chan *chan;
-+	struct gdma_dma_dev *dma_dev;
-+	struct dma_device *dd;
-+	unsigned int i;
-+	struct resource *res;
-+	uint32_t gct;
-+	int ret;
-+	int irq;
-+
-+
-+	dma_dev = devm_kzalloc(&pdev->dev, sizeof(*dma_dev), GFP_KERNEL);
-+	if (!dma_dev)
-+		return -EINVAL;
-+
-+	dd = &dma_dev->ddev;
-+
-+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-+	dma_dev->base = devm_ioremap_resource(&pdev->dev, res);
-+	if (IS_ERR(dma_dev->base))
-+		return PTR_ERR(dma_dev->base);
-+
-+	dma_cap_set(DMA_SLAVE, dd->cap_mask);
-+	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
-+	dd->device_alloc_chan_resources = gdma_dma_alloc_chan_resources;
-+	dd->device_free_chan_resources = gdma_dma_free_chan_resources;
-+	dd->device_tx_status = gdma_dma_tx_status;
-+	dd->device_issue_pending = gdma_dma_issue_pending;
-+	dd->device_prep_slave_sg = gdma_dma_prep_slave_sg;
-+	dd->device_prep_dma_cyclic = gdma_dma_prep_dma_cyclic;
-+	dd->device_control = gdma_dma_control;
-+	dd->dev = &pdev->dev;
-+	dd->chancnt = GDMA_NR_CHANS;
-+	INIT_LIST_HEAD(&dd->channels);
-+
-+	for (i = 0; i < dd->chancnt; i++) {
-+		chan = &dma_dev->chan[i];
-+		chan->id = i;
-+		chan->vchan.desc_free = gdma_dma_desc_free;
-+		vchan_init(&chan->vchan, dd);
-+	}
-+
-+	ret = dma_async_device_register(dd);
-+	if (ret)
-+		return ret;
-+
-+	ret = of_dma_controller_register(pdev->dev.of_node,
-+		of_dma_xlate_by_chan_id, dma_dev);
-+	if (ret)
-+		goto err_unregister;
-+
-+	irq = platform_get_irq(pdev, 0);
-+	ret = request_irq(irq, gdma_dma_irq, 0, dev_name(&pdev->dev), dma_dev);
-+	if (ret)
-+		goto err_unregister;
-+
-+	gdma_dma_write(dma_dev, GDMA_REG_UNMASK_INT, 0);
-+	gdma_dma_write(dma_dev, GDMA_REG_DONE_INT, BIT(dd->chancnt) - 1);
-+
-+	gct = gdma_dma_read(dma_dev, GDMA_REG_GCT);
-+	dev_info(&pdev->dev, "revision: %d, channels: %d\n",
-+		(gct >> GDMA_REG_GCT_VER_SHIFT) & GDMA_REG_GCT_VER_MASK,
-+		8 << ((gct >> GDMA_REG_GCT_CHAN_SHIFT) & GDMA_REG_GCT_CHAN_MASK));
-+	platform_set_drvdata(pdev, dma_dev);
-+
-+	gdma_dma_write(dma_dev, GDMA_REG_GCT, GDMA_REG_GCT_ARBIT_RR);
-+
-+	return 0;
-+
-+err_unregister:
-+	dma_async_device_unregister(dd);
-+	return ret;
-+}
-+
-+static int gdma_dma_remove(struct platform_device *pdev)
-+{
-+	struct gdma_dma_dev *dma_dev = platform_get_drvdata(pdev);
-+	int irq = platform_get_irq(pdev, 0);
-+
-+	free_irq(irq, dma_dev);
-+        of_dma_controller_free(pdev->dev.of_node);
-+	dma_async_device_unregister(&dma_dev->ddev);
-+
-+	return 0;
-+}
-+
-+static const struct of_device_id gdma_of_match_table[] = {
-+	{ .compatible = "ralink,rt2880-gdma" },
-+	{ },
-+};
-+
-+static struct platform_driver gdma_dma_driver = {
-+	.probe = gdma_dma_probe,
-+	.remove = gdma_dma_remove,
-+	.driver = {
-+		.name = "gdma-rt2880",
-+		.owner = THIS_MODULE,
-+		.of_match_table = gdma_of_match_table,
-+	},
-+};
-+module_platform_driver(gdma_dma_driver);
-+
-+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
-+MODULE_DESCRIPTION("GDMA4740 DMA driver");
-+MODULE_LICENSE("GPLv2");
---- a/include/linux/dmaengine.h
-+++ b/include/linux/dmaengine.h
-@@ -1058,6 +1058,7 @@ struct dma_chan *dma_request_slave_chann
- 						  const char *name);
- struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
- void dma_release_channel(struct dma_chan *chan);
-+struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
- #else
- static inline struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
- {