[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/dma/sun6i-dma.c b/src/kernel/linux/v4.14/drivers/dma/sun6i-dma.c
new file mode 100644
index 0000000..bcd496e
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/dma/sun6i-dma.c
@@ -0,0 +1,1250 @@
+/*
+ * Copyright (C) 2013-2014 Allwinner Tech Co., Ltd
+ * Author: Sugar <shuge@allwinnertech.com>
+ *
+ * Copyright (C) 2014 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.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.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "virt-dma.h"
+
+/*
+ * Common registers
+ */
+#define DMA_IRQ_EN(x)		((x) * 0x04)
+#define DMA_IRQ_HALF			BIT(0)
+#define DMA_IRQ_PKG			BIT(1)
+#define DMA_IRQ_QUEUE			BIT(2)
+
+#define DMA_IRQ_CHAN_NR			8
+#define DMA_IRQ_CHAN_WIDTH		4
+
+
+#define DMA_IRQ_STAT(x)		((x) * 0x04 + 0x10)
+
+#define DMA_STAT		0x30
+
+/*
+ * sun8i specific registers
+ */
+#define SUN8I_DMA_GATE		0x20
+#define SUN8I_DMA_GATE_ENABLE	0x4
+
+/*
+ * Channels specific registers
+ */
+#define DMA_CHAN_ENABLE		0x00
+#define DMA_CHAN_ENABLE_START		BIT(0)
+#define DMA_CHAN_ENABLE_STOP		0
+
+#define DMA_CHAN_PAUSE		0x04
+#define DMA_CHAN_PAUSE_PAUSE		BIT(1)
+#define DMA_CHAN_PAUSE_RESUME		0
+
+#define DMA_CHAN_LLI_ADDR	0x08
+
+#define DMA_CHAN_CUR_CFG	0x0c
+#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & 0x1f)
+#define DMA_CHAN_CFG_SRC_IO_MODE	BIT(5)
+#define DMA_CHAN_CFG_SRC_LINEAR_MODE	(0 << 5)
+#define DMA_CHAN_CFG_SRC_BURST(x)	(((x) & 0x3) << 7)
+#define DMA_CHAN_CFG_SRC_WIDTH(x)	(((x) & 0x3) << 9)
+
+#define DMA_CHAN_CFG_DST_DRQ(x)		(DMA_CHAN_CFG_SRC_DRQ(x) << 16)
+#define DMA_CHAN_CFG_DST_IO_MODE	(DMA_CHAN_CFG_SRC_IO_MODE << 16)
+#define DMA_CHAN_CFG_DST_LINEAR_MODE	(DMA_CHAN_CFG_SRC_LINEAR_MODE << 16)
+#define DMA_CHAN_CFG_DST_BURST(x)	(DMA_CHAN_CFG_SRC_BURST(x) << 16)
+#define DMA_CHAN_CFG_DST_WIDTH(x)	(DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
+
+#define DMA_CHAN_CUR_SRC	0x10
+
+#define DMA_CHAN_CUR_DST	0x14
+
+#define DMA_CHAN_CUR_CNT	0x18
+
+#define DMA_CHAN_CUR_PARA	0x1c
+
+
+/*
+ * Various hardware related defines
+ */
+#define LLI_LAST_ITEM	0xfffff800
+#define NORMAL_WAIT	8
+#define DRQ_SDRAM	1
+
+/*
+ * Hardware channels / ports representation
+ *
+ * The hardware is used in several SoCs, with differing numbers
+ * of channels and endpoints. This structure ties those numbers
+ * to a certain compatible string.
+ */
+struct sun6i_dma_config {
+	u32 nr_max_channels;
+	u32 nr_max_requests;
+	u32 nr_max_vchans;
+	/*
+	 * In the datasheets/user manuals of newer Allwinner SoCs, a special
+	 * bit (bit 2 at register 0x20) is present.
+	 * It's named "DMA MCLK interface circuit auto gating bit" in the
+	 * documents, and the footnote of this register says that this bit
+	 * should be set up when initializing the DMA controller.
+	 * Allwinner A23/A33 user manuals do not have this bit documented,
+	 * however these SoCs really have and need this bit, as seen in the
+	 * BSP kernel source code.
+	 */
+	bool gate_needed;
+};
+
+/*
+ * Hardware representation of the LLI
+ *
+ * The hardware will be fed the physical address of this structure,
+ * and read its content in order to start the transfer.
+ */
+struct sun6i_dma_lli {
+	u32			cfg;
+	u32			src;
+	u32			dst;
+	u32			len;
+	u32			para;
+	u32			p_lli_next;
+
+	/*
+	 * This field is not used by the DMA controller, but will be
+	 * used by the CPU to go through the list (mostly for dumping
+	 * or freeing it).
+	 */
+	struct sun6i_dma_lli	*v_lli_next;
+};
+
+
+struct sun6i_desc {
+	struct virt_dma_desc	vd;
+	dma_addr_t		p_lli;
+	struct sun6i_dma_lli	*v_lli;
+};
+
+struct sun6i_pchan {
+	u32			idx;
+	void __iomem		*base;
+	struct sun6i_vchan	*vchan;
+	struct sun6i_desc	*desc;
+	struct sun6i_desc	*done;
+};
+
+struct sun6i_vchan {
+	struct virt_dma_chan	vc;
+	struct list_head	node;
+	struct dma_slave_config	cfg;
+	struct sun6i_pchan	*phy;
+	u8			port;
+	u8			irq_type;
+	bool			cyclic;
+};
+
+struct sun6i_dma_dev {
+	struct dma_device	slave;
+	void __iomem		*base;
+	struct clk		*clk;
+	int			irq;
+	spinlock_t		lock;
+	struct reset_control	*rstc;
+	struct tasklet_struct	task;
+	atomic_t		tasklet_shutdown;
+	struct list_head	pending;
+	struct dma_pool		*pool;
+	struct sun6i_pchan	*pchans;
+	struct sun6i_vchan	*vchans;
+	const struct sun6i_dma_config *cfg;
+};
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+	return &chan->dev->device;
+}
+
+static inline struct sun6i_dma_dev *to_sun6i_dma_dev(struct dma_device *d)
+{
+	return container_of(d, struct sun6i_dma_dev, slave);
+}
+
+static inline struct sun6i_vchan *to_sun6i_vchan(struct dma_chan *chan)
+{
+	return container_of(chan, struct sun6i_vchan, vc.chan);
+}
+
+static inline struct sun6i_desc *
+to_sun6i_desc(struct dma_async_tx_descriptor *tx)
+{
+	return container_of(tx, struct sun6i_desc, vd.tx);
+}
+
+static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
+{
+	dev_dbg(sdev->slave.dev, "Common register:\n"
+		"\tmask0(%04x): 0x%08x\n"
+		"\tmask1(%04x): 0x%08x\n"
+		"\tpend0(%04x): 0x%08x\n"
+		"\tpend1(%04x): 0x%08x\n"
+		"\tstats(%04x): 0x%08x\n",
+		DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
+		DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
+		DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
+		DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
+		DMA_STAT, readl(sdev->base + DMA_STAT));
+}
+
+static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
+					    struct sun6i_pchan *pchan)
+{
+	phys_addr_t reg = virt_to_phys(pchan->base);
+
+	dev_dbg(sdev->slave.dev, "Chan %d reg: %pa\n"
+		"\t___en(%04x): \t0x%08x\n"
+		"\tpause(%04x): \t0x%08x\n"
+		"\tstart(%04x): \t0x%08x\n"
+		"\t__cfg(%04x): \t0x%08x\n"
+		"\t__src(%04x): \t0x%08x\n"
+		"\t__dst(%04x): \t0x%08x\n"
+		"\tcount(%04x): \t0x%08x\n"
+		"\t_para(%04x): \t0x%08x\n\n",
+		pchan->idx, &reg,
+		DMA_CHAN_ENABLE,
+		readl(pchan->base + DMA_CHAN_ENABLE),
+		DMA_CHAN_PAUSE,
+		readl(pchan->base + DMA_CHAN_PAUSE),
+		DMA_CHAN_LLI_ADDR,
+		readl(pchan->base + DMA_CHAN_LLI_ADDR),
+		DMA_CHAN_CUR_CFG,
+		readl(pchan->base + DMA_CHAN_CUR_CFG),
+		DMA_CHAN_CUR_SRC,
+		readl(pchan->base + DMA_CHAN_CUR_SRC),
+		DMA_CHAN_CUR_DST,
+		readl(pchan->base + DMA_CHAN_CUR_DST),
+		DMA_CHAN_CUR_CNT,
+		readl(pchan->base + DMA_CHAN_CUR_CNT),
+		DMA_CHAN_CUR_PARA,
+		readl(pchan->base + DMA_CHAN_CUR_PARA));
+}
+
+static inline s8 convert_burst(u32 maxburst)
+{
+	switch (maxburst) {
+	case 1:
+		return 0;
+	case 8:
+		return 2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width)
+{
+	if ((addr_width < DMA_SLAVE_BUSWIDTH_1_BYTE) ||
+	    (addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
+		return -EINVAL;
+
+	return addr_width >> 1;
+}
+
+static size_t sun6i_get_chan_size(struct sun6i_pchan *pchan)
+{
+	struct sun6i_desc *txd = pchan->desc;
+	struct sun6i_dma_lli *lli;
+	size_t bytes;
+	dma_addr_t pos;
+
+	pos = readl(pchan->base + DMA_CHAN_LLI_ADDR);
+	bytes = readl(pchan->base + DMA_CHAN_CUR_CNT);
+
+	if (pos == LLI_LAST_ITEM)
+		return bytes;
+
+	for (lli = txd->v_lli; lli; lli = lli->v_lli_next) {
+		if (lli->p_lli_next == pos) {
+			for (lli = lli->v_lli_next; lli; lli = lli->v_lli_next)
+				bytes += lli->len;
+			break;
+		}
+	}
+
+	return bytes;
+}
+
+static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
+			       struct sun6i_dma_lli *next,
+			       dma_addr_t next_phy,
+			       struct sun6i_desc *txd)
+{
+	if ((!prev && !txd) || !next)
+		return NULL;
+
+	if (!prev) {
+		txd->p_lli = next_phy;
+		txd->v_lli = next;
+	} else {
+		prev->p_lli_next = next_phy;
+		prev->v_lli_next = next;
+	}
+
+	next->p_lli_next = LLI_LAST_ITEM;
+	next->v_lli_next = NULL;
+
+	return next;
+}
+
+static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
+				      struct sun6i_dma_lli *lli)
+{
+	phys_addr_t p_lli = virt_to_phys(lli);
+
+	dev_dbg(chan2dev(&vchan->vc.chan),
+		"\n\tdesc:   p - %pa v - 0x%p\n"
+		"\t\tc - 0x%08x s - 0x%08x d - 0x%08x\n"
+		"\t\tl - 0x%08x p - 0x%08x n - 0x%08x\n",
+		&p_lli, lli,
+		lli->cfg, lli->src, lli->dst,
+		lli->len, lli->para, lli->p_lli_next);
+}
+
+static void sun6i_dma_free_desc(struct virt_dma_desc *vd)
+{
+	struct sun6i_desc *txd = to_sun6i_desc(&vd->tx);
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device);
+	struct sun6i_dma_lli *v_lli, *v_next;
+	dma_addr_t p_lli, p_next;
+
+	if (unlikely(!txd))
+		return;
+
+	p_lli = txd->p_lli;
+	v_lli = txd->v_lli;
+
+	while (v_lli) {
+		v_next = v_lli->v_lli_next;
+		p_next = v_lli->p_lli_next;
+
+		dma_pool_free(sdev->pool, v_lli, p_lli);
+
+		v_lli = v_next;
+		p_lli = p_next;
+	}
+
+	kfree(txd);
+}
+
+static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
+	struct virt_dma_desc *desc = vchan_next_desc(&vchan->vc);
+	struct sun6i_pchan *pchan = vchan->phy;
+	u32 irq_val, irq_reg, irq_offset;
+
+	if (!pchan)
+		return -EAGAIN;
+
+	if (!desc) {
+		pchan->desc = NULL;
+		pchan->done = NULL;
+		return -EAGAIN;
+	}
+
+	list_del(&desc->node);
+
+	pchan->desc = to_sun6i_desc(&desc->tx);
+	pchan->done = NULL;
+
+	sun6i_dma_dump_lli(vchan, pchan->desc->v_lli);
+
+	irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
+	irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
+
+	vchan->irq_type = vchan->cyclic ? DMA_IRQ_PKG : DMA_IRQ_QUEUE;
+
+	irq_val = readl(sdev->base + DMA_IRQ_EN(irq_reg));
+	irq_val &= ~((DMA_IRQ_HALF | DMA_IRQ_PKG | DMA_IRQ_QUEUE) <<
+			(irq_offset * DMA_IRQ_CHAN_WIDTH));
+	irq_val |= vchan->irq_type << (irq_offset * DMA_IRQ_CHAN_WIDTH);
+	writel(irq_val, sdev->base + DMA_IRQ_EN(irq_reg));
+
+	writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
+	writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
+
+	sun6i_dma_dump_com_regs(sdev);
+	sun6i_dma_dump_chan_regs(sdev, pchan);
+
+	return 0;
+}
+
+static void sun6i_dma_tasklet(unsigned long data)
+{
+	struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
+	const struct sun6i_dma_config *cfg = sdev->cfg;
+	struct sun6i_vchan *vchan;
+	struct sun6i_pchan *pchan;
+	unsigned int pchan_alloc = 0;
+	unsigned int pchan_idx;
+
+	list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) {
+		spin_lock_irq(&vchan->vc.lock);
+
+		pchan = vchan->phy;
+
+		if (pchan && pchan->done) {
+			if (sun6i_dma_start_desc(vchan)) {
+				/*
+				 * No current txd associated with this channel
+				 */
+				dev_dbg(sdev->slave.dev, "pchan %u: free\n",
+					pchan->idx);
+
+				/* Mark this channel free */
+				vchan->phy = NULL;
+				pchan->vchan = NULL;
+			}
+		}
+		spin_unlock_irq(&vchan->vc.lock);
+	}
+
+	spin_lock_irq(&sdev->lock);
+	for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
+		pchan = &sdev->pchans[pchan_idx];
+
+		if (pchan->vchan || list_empty(&sdev->pending))
+			continue;
+
+		vchan = list_first_entry(&sdev->pending,
+					 struct sun6i_vchan, node);
+
+		/* Remove from pending channels */
+		list_del_init(&vchan->node);
+		pchan_alloc |= BIT(pchan_idx);
+
+		/* Mark this channel allocated */
+		pchan->vchan = vchan;
+		vchan->phy = pchan;
+		dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n",
+			pchan->idx, &vchan->vc);
+	}
+	spin_unlock_irq(&sdev->lock);
+
+	for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
+		if (!(pchan_alloc & BIT(pchan_idx)))
+			continue;
+
+		pchan = sdev->pchans + pchan_idx;
+		vchan = pchan->vchan;
+		if (vchan) {
+			spin_lock_irq(&vchan->vc.lock);
+			sun6i_dma_start_desc(vchan);
+			spin_unlock_irq(&vchan->vc.lock);
+		}
+	}
+}
+
+static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
+{
+	struct sun6i_dma_dev *sdev = dev_id;
+	struct sun6i_vchan *vchan;
+	struct sun6i_pchan *pchan;
+	int i, j, ret = IRQ_NONE;
+	u32 status;
+
+	for (i = 0; i < sdev->cfg->nr_max_channels / DMA_IRQ_CHAN_NR; i++) {
+		status = readl(sdev->base + DMA_IRQ_STAT(i));
+		if (!status)
+			continue;
+
+		dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
+			i ? "high" : "low", status);
+
+		writel(status, sdev->base + DMA_IRQ_STAT(i));
+
+		for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
+			pchan = sdev->pchans + j;
+			vchan = pchan->vchan;
+			if (vchan && (status & vchan->irq_type)) {
+				if (vchan->cyclic) {
+					vchan_cyclic_callback(&pchan->desc->vd);
+				} else {
+					spin_lock(&vchan->vc.lock);
+					vchan_cookie_complete(&pchan->desc->vd);
+					pchan->done = pchan->desc;
+					spin_unlock(&vchan->vc.lock);
+				}
+			}
+
+			status = status >> DMA_IRQ_CHAN_WIDTH;
+		}
+
+		if (!atomic_read(&sdev->tasklet_shutdown))
+			tasklet_schedule(&sdev->task);
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static int set_config(struct sun6i_dma_dev *sdev,
+			struct dma_slave_config *sconfig,
+			enum dma_transfer_direction direction,
+			u32 *p_cfg)
+{
+	s8 src_width, dst_width, src_burst, dst_burst;
+
+	switch (direction) {
+	case DMA_MEM_TO_DEV:
+		src_burst = convert_burst(sconfig->src_maxburst ?
+					sconfig->src_maxburst : 8);
+		src_width = convert_buswidth(sconfig->src_addr_width !=
+						DMA_SLAVE_BUSWIDTH_UNDEFINED ?
+				sconfig->src_addr_width :
+				DMA_SLAVE_BUSWIDTH_4_BYTES);
+		dst_burst = convert_burst(sconfig->dst_maxburst);
+		dst_width = convert_buswidth(sconfig->dst_addr_width);
+		break;
+	case DMA_DEV_TO_MEM:
+		src_burst = convert_burst(sconfig->src_maxburst);
+		src_width = convert_buswidth(sconfig->src_addr_width);
+		dst_burst = convert_burst(sconfig->dst_maxburst ?
+					sconfig->dst_maxburst : 8);
+		dst_width = convert_buswidth(sconfig->dst_addr_width !=
+						DMA_SLAVE_BUSWIDTH_UNDEFINED ?
+				sconfig->dst_addr_width :
+				DMA_SLAVE_BUSWIDTH_4_BYTES);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (src_burst < 0)
+		return src_burst;
+	if (src_width < 0)
+		return src_width;
+	if (dst_burst < 0)
+		return dst_burst;
+	if (dst_width < 0)
+		return dst_width;
+
+	*p_cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
+		DMA_CHAN_CFG_SRC_WIDTH(src_width) |
+		DMA_CHAN_CFG_DST_BURST(dst_burst) |
+		DMA_CHAN_CFG_DST_WIDTH(dst_width);
+
+	return 0;
+}
+
+static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
+		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+		size_t len, unsigned long flags)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct sun6i_dma_lli *v_lli;
+	struct sun6i_desc *txd;
+	dma_addr_t p_lli;
+	s8 burst, width;
+
+	dev_dbg(chan2dev(chan),
+		"%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
+		__func__, vchan->vc.chan.chan_id, &dest, &src, len, flags);
+
+	if (!len)
+		return NULL;
+
+	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+	if (!txd)
+		return NULL;
+
+	v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
+	if (!v_lli) {
+		dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
+		goto err_txd_free;
+	}
+
+	v_lli->src = src;
+	v_lli->dst = dest;
+	v_lli->len = len;
+	v_lli->para = NORMAL_WAIT;
+
+	burst = convert_burst(8);
+	width = convert_buswidth(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	v_lli->cfg = DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
+		DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
+		DMA_CHAN_CFG_DST_LINEAR_MODE |
+		DMA_CHAN_CFG_SRC_LINEAR_MODE |
+		DMA_CHAN_CFG_SRC_BURST(burst) |
+		DMA_CHAN_CFG_SRC_WIDTH(width) |
+		DMA_CHAN_CFG_DST_BURST(burst) |
+		DMA_CHAN_CFG_DST_WIDTH(width);
+
+	sun6i_dma_lli_add(NULL, v_lli, p_lli, txd);
+
+	sun6i_dma_dump_lli(vchan, v_lli);
+
+	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_txd_free:
+	kfree(txd);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction dir,
+		unsigned long flags, void *context)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct dma_slave_config *sconfig = &vchan->cfg;
+	struct sun6i_dma_lli *v_lli, *prev = NULL;
+	struct sun6i_desc *txd;
+	struct scatterlist *sg;
+	dma_addr_t p_lli;
+	u32 lli_cfg;
+	int i, ret;
+
+	if (!sgl)
+		return NULL;
+
+	ret = set_config(sdev, sconfig, dir, &lli_cfg);
+	if (ret) {
+		dev_err(chan2dev(chan), "Invalid DMA configuration\n");
+		return NULL;
+	}
+
+	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+	if (!txd)
+		return NULL;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
+		if (!v_lli)
+			goto err_lli_free;
+
+		v_lli->len = sg_dma_len(sg);
+		v_lli->para = NORMAL_WAIT;
+
+		if (dir == DMA_MEM_TO_DEV) {
+			v_lli->src = sg_dma_address(sg);
+			v_lli->dst = sconfig->dst_addr;
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_IO_MODE |
+				DMA_CHAN_CFG_SRC_LINEAR_MODE |
+				DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
+				DMA_CHAN_CFG_DST_DRQ(vchan->port);
+
+			dev_dbg(chan2dev(chan),
+				"%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
+				__func__, vchan->vc.chan.chan_id,
+				&sconfig->dst_addr, &sg_dma_address(sg),
+				sg_dma_len(sg), flags);
+
+		} else {
+			v_lli->src = sconfig->src_addr;
+			v_lli->dst = sg_dma_address(sg);
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_LINEAR_MODE |
+				DMA_CHAN_CFG_SRC_IO_MODE |
+				DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
+				DMA_CHAN_CFG_SRC_DRQ(vchan->port);
+
+			dev_dbg(chan2dev(chan),
+				"%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
+				__func__, vchan->vc.chan.chan_id,
+				&sg_dma_address(sg), &sconfig->src_addr,
+				sg_dma_len(sg), flags);
+		}
+
+		prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
+	}
+
+	dev_dbg(chan2dev(chan), "First: %pad\n", &txd->p_lli);
+	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
+		sun6i_dma_dump_lli(vchan, prev);
+
+	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_lli_free:
+	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
+		dma_pool_free(sdev->pool, prev, virt_to_phys(prev));
+	kfree(txd);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *sun6i_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,
+					unsigned long flags)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct dma_slave_config *sconfig = &vchan->cfg;
+	struct sun6i_dma_lli *v_lli, *prev = NULL;
+	struct sun6i_desc *txd;
+	dma_addr_t p_lli;
+	u32 lli_cfg;
+	unsigned int i, periods = buf_len / period_len;
+	int ret;
+
+	ret = set_config(sdev, sconfig, dir, &lli_cfg);
+	if (ret) {
+		dev_err(chan2dev(chan), "Invalid DMA configuration\n");
+		return NULL;
+	}
+
+	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+	if (!txd)
+		return NULL;
+
+	for (i = 0; i < periods; i++) {
+		v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
+		if (!v_lli) {
+			dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
+			goto err_lli_free;
+		}
+
+		v_lli->len = period_len;
+		v_lli->para = NORMAL_WAIT;
+
+		if (dir == DMA_MEM_TO_DEV) {
+			v_lli->src = buf_addr + period_len * i;
+			v_lli->dst = sconfig->dst_addr;
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_IO_MODE |
+				DMA_CHAN_CFG_SRC_LINEAR_MODE |
+				DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
+				DMA_CHAN_CFG_DST_DRQ(vchan->port);
+		} else {
+			v_lli->src = sconfig->src_addr;
+			v_lli->dst = buf_addr + period_len * i;
+			v_lli->cfg = lli_cfg |
+				DMA_CHAN_CFG_DST_LINEAR_MODE |
+				DMA_CHAN_CFG_SRC_IO_MODE |
+				DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
+				DMA_CHAN_CFG_SRC_DRQ(vchan->port);
+		}
+
+		prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
+	}
+
+	prev->p_lli_next = txd->p_lli;		/* cyclic list */
+
+	vchan->cyclic = true;
+
+	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_lli_free:
+	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
+		dma_pool_free(sdev->pool, prev, virt_to_phys(prev));
+	kfree(txd);
+	return NULL;
+}
+
+static int sun6i_dma_config(struct dma_chan *chan,
+			    struct dma_slave_config *config)
+{
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+
+	memcpy(&vchan->cfg, config, sizeof(*config));
+
+	return 0;
+}
+
+static int sun6i_dma_pause(struct dma_chan *chan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct sun6i_pchan *pchan = vchan->phy;
+
+	dev_dbg(chan2dev(chan), "vchan %p: pause\n", &vchan->vc);
+
+	if (pchan) {
+		writel(DMA_CHAN_PAUSE_PAUSE,
+		       pchan->base + DMA_CHAN_PAUSE);
+	} else {
+		spin_lock(&sdev->lock);
+		list_del_init(&vchan->node);
+		spin_unlock(&sdev->lock);
+	}
+
+	return 0;
+}
+
+static int sun6i_dma_resume(struct dma_chan *chan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct sun6i_pchan *pchan = vchan->phy;
+	unsigned long flags;
+
+	dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	if (pchan) {
+		writel(DMA_CHAN_PAUSE_RESUME,
+		       pchan->base + DMA_CHAN_PAUSE);
+	} else if (!list_empty(&vchan->vc.desc_issued)) {
+		spin_lock(&sdev->lock);
+		list_add_tail(&vchan->node, &sdev->pending);
+		spin_unlock(&sdev->lock);
+	}
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+	return 0;
+}
+
+static int sun6i_dma_terminate_all(struct dma_chan *chan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct sun6i_pchan *pchan = vchan->phy;
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock(&sdev->lock);
+	list_del_init(&vchan->node);
+	spin_unlock(&sdev->lock);
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	if (vchan->cyclic) {
+		vchan->cyclic = false;
+		if (pchan && pchan->desc) {
+			struct virt_dma_desc *vd = &pchan->desc->vd;
+			struct virt_dma_chan *vc = &vchan->vc;
+
+			list_add_tail(&vd->node, &vc->desc_completed);
+		}
+	}
+
+	vchan_get_all_descriptors(&vchan->vc, &head);
+
+	if (pchan) {
+		writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
+		writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
+
+		vchan->phy = NULL;
+		pchan->vchan = NULL;
+		pchan->desc = NULL;
+		pchan->done = NULL;
+	}
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+	vchan_dma_desc_free_list(&vchan->vc, &head);
+
+	return 0;
+}
+
+static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan,
+					   dma_cookie_t cookie,
+					   struct dma_tx_state *state)
+{
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	struct sun6i_pchan *pchan = vchan->phy;
+	struct sun6i_dma_lli *lli;
+	struct virt_dma_desc *vd;
+	struct sun6i_desc *txd;
+	enum dma_status ret;
+	unsigned long flags;
+	size_t bytes = 0;
+
+	ret = dma_cookie_status(chan, cookie, state);
+	if (ret == DMA_COMPLETE || !state)
+		return ret;
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	vd = vchan_find_desc(&vchan->vc, cookie);
+	txd = to_sun6i_desc(&vd->tx);
+
+	if (vd) {
+		for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next)
+			bytes += lli->len;
+	} else if (!pchan || !pchan->desc) {
+		bytes = 0;
+	} else {
+		bytes = sun6i_get_chan_size(pchan);
+	}
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+	dma_set_residue(state, bytes);
+
+	return ret;
+}
+
+static void sun6i_dma_issue_pending(struct dma_chan *chan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vchan->vc.lock, flags);
+
+	if (vchan_issue_pending(&vchan->vc)) {
+		spin_lock(&sdev->lock);
+
+		if (!vchan->phy && list_empty(&vchan->node)) {
+			list_add_tail(&vchan->node, &sdev->pending);
+			tasklet_schedule(&sdev->task);
+			dev_dbg(chan2dev(chan), "vchan %p: issued\n",
+				&vchan->vc);
+		}
+
+		spin_unlock(&sdev->lock);
+	} else {
+		dev_dbg(chan2dev(chan), "vchan %p: nothing to issue\n",
+			&vchan->vc);
+	}
+
+	spin_unlock_irqrestore(&vchan->vc.lock, flags);
+}
+
+static void sun6i_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&sdev->lock, flags);
+	list_del_init(&vchan->node);
+	spin_unlock_irqrestore(&sdev->lock, flags);
+
+	vchan_free_chan_resources(&vchan->vc);
+}
+
+static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
+					   struct of_dma *ofdma)
+{
+	struct sun6i_dma_dev *sdev = ofdma->of_dma_data;
+	struct sun6i_vchan *vchan;
+	struct dma_chan *chan;
+	u8 port = dma_spec->args[0];
+
+	if (port > sdev->cfg->nr_max_requests)
+		return NULL;
+
+	chan = dma_get_any_slave_channel(&sdev->slave);
+	if (!chan)
+		return NULL;
+
+	vchan = to_sun6i_vchan(chan);
+	vchan->port = port;
+
+	return chan;
+}
+
+static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
+{
+	/* Disable all interrupts from DMA */
+	writel(0, sdev->base + DMA_IRQ_EN(0));
+	writel(0, sdev->base + DMA_IRQ_EN(1));
+
+	/* Prevent spurious interrupts from scheduling the tasklet */
+	atomic_inc(&sdev->tasklet_shutdown);
+
+	/* Make sure we won't have any further interrupts */
+	devm_free_irq(sdev->slave.dev, sdev->irq, sdev);
+
+	/* Actually prevent the tasklet from being scheduled */
+	tasklet_kill(&sdev->task);
+}
+
+static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
+{
+	int i;
+
+	for (i = 0; i < sdev->cfg->nr_max_vchans; i++) {
+		struct sun6i_vchan *vchan = &sdev->vchans[i];
+
+		list_del(&vchan->vc.chan.device_node);
+		tasklet_kill(&vchan->vc.task);
+	}
+}
+
+/*
+ * For A31:
+ *
+ * There's 16 physical channels that can work in parallel.
+ *
+ * However we have 30 different endpoints for our requests.
+ *
+ * Since the channels are able to handle only an unidirectional
+ * transfer, we need to allocate more virtual channels so that
+ * everyone can grab one channel.
+ *
+ * Some devices can't work in both direction (mostly because it
+ * wouldn't make sense), so we have a bit fewer virtual channels than
+ * 2 channels per endpoints.
+ */
+
+static struct sun6i_dma_config sun6i_a31_dma_cfg = {
+	.nr_max_channels = 16,
+	.nr_max_requests = 30,
+	.nr_max_vchans   = 53,
+};
+
+/*
+ * The A23 only has 8 physical channels, a maximum DRQ port id of 24,
+ * and a total of 37 usable source and destination endpoints.
+ */
+
+static struct sun6i_dma_config sun8i_a23_dma_cfg = {
+	.nr_max_channels = 8,
+	.nr_max_requests = 24,
+	.nr_max_vchans   = 37,
+	.gate_needed	 = true,
+};
+
+static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
+	.nr_max_channels = 8,
+	.nr_max_requests = 28,
+	.nr_max_vchans   = 39,
+};
+
+/*
+ * The H3 has 12 physical channels, a maximum DRQ port id of 27,
+ * and a total of 34 usable source and destination endpoints.
+ */
+
+static struct sun6i_dma_config sun8i_h3_dma_cfg = {
+	.nr_max_channels = 12,
+	.nr_max_requests = 27,
+	.nr_max_vchans   = 34,
+};
+
+/*
+ * The V3s have only 8 physical channels, a maximum DRQ port id of 23,
+ * and a total of 24 usable source and destination endpoints.
+ */
+
+static struct sun6i_dma_config sun8i_v3s_dma_cfg = {
+	.nr_max_channels = 8,
+	.nr_max_requests = 23,
+	.nr_max_vchans   = 24,
+	.gate_needed	 = true,
+};
+
+static const struct of_device_id sun6i_dma_match[] = {
+	{ .compatible = "allwinner,sun6i-a31-dma", .data = &sun6i_a31_dma_cfg },
+	{ .compatible = "allwinner,sun8i-a23-dma", .data = &sun8i_a23_dma_cfg },
+	{ .compatible = "allwinner,sun8i-a83t-dma", .data = &sun8i_a83t_dma_cfg },
+	{ .compatible = "allwinner,sun8i-h3-dma", .data = &sun8i_h3_dma_cfg },
+	{ .compatible = "allwinner,sun8i-v3s-dma", .data = &sun8i_v3s_dma_cfg },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun6i_dma_match);
+
+static int sun6i_dma_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *device;
+	struct sun6i_dma_dev *sdc;
+	struct resource *res;
+	int ret, i;
+
+	sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
+	if (!sdc)
+		return -ENOMEM;
+
+	device = of_match_device(sun6i_dma_match, &pdev->dev);
+	if (!device)
+		return -ENODEV;
+	sdc->cfg = device->data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sdc->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(sdc->base))
+		return PTR_ERR(sdc->base);
+
+	sdc->irq = platform_get_irq(pdev, 0);
+	if (sdc->irq < 0) {
+		dev_err(&pdev->dev, "Cannot claim IRQ\n");
+		return sdc->irq;
+	}
+
+	sdc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sdc->clk)) {
+		dev_err(&pdev->dev, "No clock specified\n");
+		return PTR_ERR(sdc->clk);
+	}
+
+	sdc->rstc = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(sdc->rstc)) {
+		dev_err(&pdev->dev, "No reset controller specified\n");
+		return PTR_ERR(sdc->rstc);
+	}
+
+	sdc->pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
+				     sizeof(struct sun6i_dma_lli), 4, 0);
+	if (!sdc->pool) {
+		dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, sdc);
+	INIT_LIST_HEAD(&sdc->pending);
+	spin_lock_init(&sdc->lock);
+
+	dma_cap_set(DMA_PRIVATE, sdc->slave.cap_mask);
+	dma_cap_set(DMA_MEMCPY, sdc->slave.cap_mask);
+	dma_cap_set(DMA_SLAVE, sdc->slave.cap_mask);
+	dma_cap_set(DMA_CYCLIC, sdc->slave.cap_mask);
+
+	INIT_LIST_HEAD(&sdc->slave.channels);
+	sdc->slave.device_free_chan_resources	= sun6i_dma_free_chan_resources;
+	sdc->slave.device_tx_status		= sun6i_dma_tx_status;
+	sdc->slave.device_issue_pending		= sun6i_dma_issue_pending;
+	sdc->slave.device_prep_slave_sg		= sun6i_dma_prep_slave_sg;
+	sdc->slave.device_prep_dma_memcpy	= sun6i_dma_prep_dma_memcpy;
+	sdc->slave.device_prep_dma_cyclic	= sun6i_dma_prep_dma_cyclic;
+	sdc->slave.copy_align			= DMAENGINE_ALIGN_4_BYTES;
+	sdc->slave.device_config		= sun6i_dma_config;
+	sdc->slave.device_pause			= sun6i_dma_pause;
+	sdc->slave.device_resume		= sun6i_dma_resume;
+	sdc->slave.device_terminate_all		= sun6i_dma_terminate_all;
+	sdc->slave.src_addr_widths		= BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+						  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+						  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	sdc->slave.dst_addr_widths		= BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+						  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+						  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+	sdc->slave.directions			= BIT(DMA_DEV_TO_MEM) |
+						  BIT(DMA_MEM_TO_DEV);
+	sdc->slave.residue_granularity		= DMA_RESIDUE_GRANULARITY_BURST;
+	sdc->slave.dev = &pdev->dev;
+
+	sdc->pchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_channels,
+				   sizeof(struct sun6i_pchan), GFP_KERNEL);
+	if (!sdc->pchans)
+		return -ENOMEM;
+
+	sdc->vchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_vchans,
+				   sizeof(struct sun6i_vchan), GFP_KERNEL);
+	if (!sdc->vchans)
+		return -ENOMEM;
+
+	tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
+
+	for (i = 0; i < sdc->cfg->nr_max_channels; i++) {
+		struct sun6i_pchan *pchan = &sdc->pchans[i];
+
+		pchan->idx = i;
+		pchan->base = sdc->base + 0x100 + i * 0x40;
+	}
+
+	for (i = 0; i < sdc->cfg->nr_max_vchans; i++) {
+		struct sun6i_vchan *vchan = &sdc->vchans[i];
+
+		INIT_LIST_HEAD(&vchan->node);
+		vchan->vc.desc_free = sun6i_dma_free_desc;
+		vchan_init(&vchan->vc, &sdc->slave);
+	}
+
+	ret = reset_control_deassert(sdc->rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't deassert the device from reset\n");
+		goto err_chan_free;
+	}
+
+	ret = clk_prepare_enable(sdc->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't enable the clock\n");
+		goto err_reset_assert;
+	}
+
+	ret = devm_request_irq(&pdev->dev, sdc->irq, sun6i_dma_interrupt, 0,
+			       dev_name(&pdev->dev), sdc);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot request IRQ\n");
+		goto err_clk_disable;
+	}
+
+	ret = dma_async_device_register(&sdc->slave);
+	if (ret) {
+		dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
+		goto err_irq_disable;
+	}
+
+	ret = of_dma_controller_register(pdev->dev.of_node, sun6i_dma_of_xlate,
+					 sdc);
+	if (ret) {
+		dev_err(&pdev->dev, "of_dma_controller_register failed\n");
+		goto err_dma_unregister;
+	}
+
+	if (sdc->cfg->gate_needed)
+		writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE);
+
+	return 0;
+
+err_dma_unregister:
+	dma_async_device_unregister(&sdc->slave);
+err_irq_disable:
+	sun6i_kill_tasklet(sdc);
+err_clk_disable:
+	clk_disable_unprepare(sdc->clk);
+err_reset_assert:
+	reset_control_assert(sdc->rstc);
+err_chan_free:
+	sun6i_dma_free(sdc);
+	return ret;
+}
+
+static int sun6i_dma_remove(struct platform_device *pdev)
+{
+	struct sun6i_dma_dev *sdc = platform_get_drvdata(pdev);
+
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&sdc->slave);
+
+	sun6i_kill_tasklet(sdc);
+
+	clk_disable_unprepare(sdc->clk);
+	reset_control_assert(sdc->rstc);
+
+	sun6i_dma_free(sdc);
+
+	return 0;
+}
+
+static struct platform_driver sun6i_dma_driver = {
+	.probe		= sun6i_dma_probe,
+	.remove		= sun6i_dma_remove,
+	.driver = {
+		.name		= "sun6i-dma",
+		.of_match_table	= sun6i_dma_match,
+	},
+};
+module_platform_driver(sun6i_dma_driver);
+
+MODULE_DESCRIPTION("Allwinner A31 DMA Controller Driver");
+MODULE_AUTHOR("Sugar <shuge@allwinnertech.com>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_LICENSE("GPL");