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-rw-r--r--target/linux/ramips/patches-4.3/0047-DMA-ralink-add-rt2880-dma-engine.patch628
1 files changed, 0 insertions, 628 deletions
diff --git a/target/linux/ramips/patches-4.3/0047-DMA-ralink-add-rt2880-dma-engine.patch b/target/linux/ramips/patches-4.3/0047-DMA-ralink-add-rt2880-dma-engine.patch
deleted file mode 100644
index 3362d4b5fc..0000000000
--- a/target/linux/ramips/patches-4.3/0047-DMA-ralink-add-rt2880-dma-engine.patch
+++ /dev/null
@@ -1,628 +0,0 @@
-From f1c4d9e622c800e1f38b3818f933ec7597d1ccfb Mon Sep 17 00:00:00 2001
-From: John Crispin <blogic@openwrt.org>
-Date: Sun, 27 Jul 2014 09:29:51 +0100
-Subject: [PATCH 47/53] DMA: ralink: add rt2880 dma engine
-
-Signed-off-by: John Crispin <blogic@openwrt.org>
----
- drivers/dma/Kconfig | 6 +
- drivers/dma/Makefile | 1 +
- drivers/dma/ralink-gdma.c | 577 +++++++++++++++++++++++++++++++++++++++++++++
- include/linux/dmaengine.h | 1 +
- 4 files changed, 585 insertions(+)
- create mode 100644 drivers/dma/ralink-gdma.c
-
---- a/drivers/dma/Kconfig
-+++ b/drivers/dma/Kconfig
-@@ -40,6 +40,12 @@ config ASYNC_TX_ENABLE_CHANNEL_SWITCH
- config ARCH_HAS_ASYNC_TX_FIND_CHANNEL
- bool
-
-+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
-@@ -65,5 +65,6 @@ obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-
- obj-$(CONFIG_TI_EDMA) += edma.o
- obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
- obj-$(CONFIG_ZX_DMA) += zx296702_dma.o
-+obj-$(CONFIG_DMA_RALINK) += ralink-gdma.o
-
- obj-y += xilinx/
---- /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
-@@ -496,6 +496,7 @@ static inline void dma_set_unmap(struct
- struct dmaengine_unmap_data *
- dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags);
- void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap);
-+struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
- #else
- static inline void dma_set_unmap(struct dma_async_tx_descriptor *tx,
- struct dmaengine_unmap_data *unmap)