dmaengine: at_hdmac: Convert driver to use virt-dma
authorTudor Ambarus <tudor.ambarus@microchip.com>
Tue, 25 Oct 2022 09:03:06 +0000 (12:03 +0300)
committerVinod Koul <vkoul@kernel.org>
Fri, 11 Nov 2022 06:45:09 +0000 (12:15 +0530)
Convert the driver to use the core virt-dma. The driver will be easier to
maintain as it uses the list handling and the tasklet from virt-dma.

With the conversion replace the election of a new transfer in the tasklet
with the election of the new transfer in the interrupt handler. With this
we have a shorter idle window as we remove the scheduling latency of the
tasklet. I chose to do this while doing the conversion to virt-dma,
because if I made a prerequisite patch with the new transfer election in
the irq handler, I would have to duplicate some virt-dma code in the
at_hdmac driver that would end up being removed at the virt-dma conversion
anyway. So do this in a single step.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-33-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/dma/Kconfig
drivers/dma/at_hdmac.c

index ea81d82..b9d54f2 100644 (file)
@@ -97,6 +97,7 @@ config AT_HDMAC
        tristate "Atmel AHB DMA support"
        depends on ARCH_AT91
        select DMA_ENGINE
+       select DMA_VIRTUAL_CHANNELS
        help
          Support the Atmel AHB DMA controller.
 
index 143d75c..8858470 100644 (file)
@@ -3,6 +3,7 @@
  * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
  *
  * Copyright (C) 2008 Atmel Corporation
+ * Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
  *
  * This supports the Atmel AHB DMA Controller found in several Atmel SoCs.
  * The only Atmel DMA Controller that is not covered by this driver is the one
@@ -25,6 +26,7 @@
 #include <linux/slab.h>
 
 #include "dmaengine.h"
+#include "virt-dma.h"
 
 /*
  * Glossary
@@ -201,24 +203,30 @@ struct at_lli {
 };
 
 /**
+ * struct atdma_sg - atdma scatter gather entry
+ * @len: length of the current Linked List Item.
+ * @lli: linked list item that is passed to the DMA controller
+ * @lli_phys: physical address of the LLI.
+ */
+struct atdma_sg {
+       unsigned int len;
+       struct at_lli *lli;
+       dma_addr_t lli_phys;
+};
+
+/**
  * struct at_desc - software descriptor
- * @at_lli: hardware lli structure
- * @txd: support for the async_tx api
- * @desc_node: node on the channed descriptors list
- * @len: descriptor byte count
+ * @vd: pointer to the virtual dma descriptor.
+ * @atchan: pointer to the atmel dma channel.
  * @total_len: total transaction byte count
+ * @sg_len: number of sg entries.
+ * @sg: array of sgs.
  */
 struct at_desc {
-       /* FIRST values the hardware uses */
-       struct at_lli                   lli;
-
-       /* THEN values for driver housekeeping */
-       struct list_head                tx_list;
-       struct dma_async_tx_descriptor  txd;
-       struct list_head                desc_node;
-       size_t                          len;
+       struct                          virt_dma_desc vd;
+       struct                          at_dma_chan *atchan;
        size_t                          total_len;
-
+       unsigned int                    sglen;
        /* Interleaved data */
        size_t                          boundary;
        size_t                          dst_hole;
@@ -228,15 +236,9 @@ struct at_desc {
        bool                            memset_buffer;
        dma_addr_t                      memset_paddr;
        int                             *memset_vaddr;
+       struct atdma_sg                 sg[];
 };
 
-static inline struct at_desc *
-txd_to_at_desc(struct dma_async_tx_descriptor *txd)
-{
-       return container_of(txd, struct at_desc, txd);
-}
-
-
 /*--  Channels  --------------------------------------------------------*/
 
 /**
@@ -245,49 +247,40 @@ txd_to_at_desc(struct dma_async_tx_descriptor *txd)
  * Manipulated with atomic operations.
  */
 enum atc_status {
-       ATC_IS_ERROR = 0,
        ATC_IS_PAUSED = 1,
        ATC_IS_CYCLIC = 24,
 };
 
 /**
  * struct at_dma_chan - internal representation of an Atmel HDMAC channel
- * @dma_chan: common dmaengine channel object members
+ * @vc: virtual dma channel entry.
+ * @atdma: pointer to the driver data.
  * @ch_regs: memory mapped register base
  * @mask: channel index in a mask
  * @per_if: peripheral interface
  * @mem_if: memory interface
  * @status: transmit status information from irq/prep* functions
  *                to tasklet (use atomic operations)
- * @tasklet: bottom half to finish transaction work
  * @save_cfg: configuration register that is saved on suspend/resume cycle
  * @save_dscr: for cyclic operations, preserve next descriptor address in
  *             the cyclic list on suspend/resume cycle
  * @dma_sconfig: configuration for slave transfers, passed via
  * .device_config
- * @lock: serializes enqueue/dequeue operations to descriptors lists
- * @active_list: list of descriptors dmaengine is being running on
- * @queue: list of descriptors ready to be submitted to engine
- * @free_list: list of descriptors usable by the channel
+ * @desc: pointer to the atmel dma descriptor.
  */
 struct at_dma_chan {
-       struct dma_chan         dma_chan;
+       struct virt_dma_chan    vc;
+       struct at_dma           *atdma;
        void __iomem            *ch_regs;
        u8                      mask;
        u8                      per_if;
        u8                      mem_if;
        unsigned long           status;
-       struct tasklet_struct   tasklet;
        u32                     save_cfg;
        u32                     save_dscr;
-       struct dma_slave_config dma_sconfig;
-
-       spinlock_t              lock;
-
-       /* these other elements are all protected by lock */
-       struct list_head        active_list;
-       struct list_head        queue;
-       struct list_head        free_list;
+       struct dma_slave_config dma_sconfig;
+       bool                    cyclic;
+       struct at_desc          *desc;
 };
 
 #define        channel_readl(atchan, name) \
@@ -296,11 +289,6 @@ struct at_dma_chan {
 #define        channel_writel(atchan, name, val) \
        __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)
 
-static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
-{
-       return container_of(dchan, struct at_dma_chan, dma_chan);
-}
-
 /*
  * Fix sconfig's burst size according to at_hdmac. We need to convert them as:
  * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
@@ -342,7 +330,7 @@ static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
  * @clk: dma controller clock
  * @save_imr: interrupt mask register that is saved on suspend/resume cycle
  * @all_chan_mask: all channels availlable in a mask
- * @dma_desc_pool: base of DMA descriptor region (DMA address)
+ * @lli_pool: hw lli table
  * @chan: channels table to store at_dma_chan structures
  */
 struct at_dma {
@@ -353,7 +341,7 @@ struct at_dma {
 
        u8                      all_chan_mask;
 
-       struct dma_pool         *dma_desc_pool;
+       struct dma_pool         *lli_pool;
        struct dma_pool         *memset_pool;
        /* AT THE END channels table */
        struct at_dma_chan      chan[];
@@ -364,6 +352,16 @@ struct at_dma {
 #define        dma_writel(atdma, name, val) \
        __raw_writel((val), (atdma)->regs + AT_DMA_##name)
 
+static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t)
+{
+       return container_of(t, struct at_desc, vd.tx);
+}
+
+static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan)
+{
+       return container_of(chan, struct at_dma_chan, vc.chan);
+}
+
 static inline struct at_dma *to_at_dma(struct dma_device *ddev)
 {
        return container_of(ddev, struct at_dma, dma_device);
@@ -380,15 +378,15 @@ static struct device *chan2dev(struct dma_chan *chan)
 #if defined(VERBOSE_DEBUG)
 static void vdbg_dump_regs(struct at_dma_chan *atchan)
 {
-       struct at_dma   *atdma = to_at_dma(atchan->dma_chan.device);
+       struct at_dma   *atdma = to_at_dma(atchan->vc.chan.device);
 
-       dev_err(chan2dev(&atchan->dma_chan),
+       dev_err(chan2dev(&atchan->vc.chan),
                "  channel %d : imr = 0x%x, chsr = 0x%x\n",
-               atchan->dma_chan.chan_id,
+               atchan->vc.chan.chan_id,
                dma_readl(atdma, EBCIMR),
                dma_readl(atdma, CHSR));
 
-       dev_err(chan2dev(&atchan->dma_chan),
+       dev_err(chan2dev(&atchan->vc.chan),
                "  channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
                channel_readl(atchan, SADDR),
                channel_readl(atchan, DADDR),
@@ -403,7 +401,7 @@ static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
 
 static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
 {
-       dev_crit(chan2dev(&atchan->dma_chan),
+       dev_crit(chan2dev(&atchan->vc.chan),
                 "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
                 &lli->saddr, &lli->daddr,
                 lli->ctrla, lli->ctrlb, &lli->dscr);
@@ -440,7 +438,7 @@ static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
  */
 static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
 {
-       struct at_dma   *atdma = to_at_dma(atchan->dma_chan.device);
+       struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);
 
        return !!(dma_readl(atdma, CHSR) & atchan->mask);
 }
@@ -464,18 +462,19 @@ static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
 }
 
 /**
- * set_desc_eol - set end-of-link to descriptor so it will end transfer
+ * set_lli_eol - set end-of-link to descriptor so it will end transfer
  * @desc: descriptor, signle or at the end of a chain, to end chain on
+ * @i: index of the atmel scatter gather entry that is at the end of the chain.
  */
-static void set_desc_eol(struct at_desc *desc)
+static void set_lli_eol(struct at_desc *desc, unsigned int i)
 {
-       u32 ctrlb = desc->lli.ctrlb;
+       u32 ctrlb = desc->sg[i].lli->ctrlb;
 
        ctrlb &= ~ATC_IEN;
        ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;
 
-       desc->lli.ctrlb = ctrlb;
-       desc->lli.dscr = 0;
+       desc->sg[i].lli->ctrlb = ctrlb;
+       desc->sg[i].lli->dscr = 0;
 }
 
 #define        ATC_DEFAULT_CFG         FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO)
@@ -518,13 +517,6 @@ struct at_dma_slave {
        u32                     cfg;
 };
 
-/* prototypes */
-static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
-static void atc_issue_pending(struct dma_chan *chan);
-
-
-/*----------------------------------------------------------------------*/
-
 static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
                                                size_t len)
 {
@@ -540,196 +532,72 @@ static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
        return width;
 }
 
-static struct at_desc *atc_first_active(struct at_dma_chan *atchan)
+static void atdma_lli_chain(struct at_desc *desc, unsigned int i)
 {
-       return list_first_entry(&atchan->active_list,
-                               struct at_desc, desc_node);
-}
+       struct atdma_sg *atdma_sg = &desc->sg[i];
 
-static struct at_desc *atc_first_queued(struct at_dma_chan *atchan)
-{
-       return list_first_entry(&atchan->queue,
-                               struct at_desc, desc_node);
-}
-
-/**
- * atc_alloc_descriptor - allocate and return an initialized descriptor
- * @chan: the channel to allocate descriptors for
- * @gfp_flags: GFP allocation flags
- *
- * Note: The ack-bit is positioned in the descriptor flag at creation time
- *       to make initial allocation more convenient. This bit will be cleared
- *       and control will be given to client at usage time (during
- *       preparation functions).
- */
-static struct at_desc *atc_alloc_descriptor(struct dma_chan *chan,
-                                           gfp_t gfp_flags)
-{
-       struct at_desc  *desc = NULL;
-       struct at_dma   *atdma = to_at_dma(chan->device);
-       dma_addr_t phys;
-
-       desc = dma_pool_zalloc(atdma->dma_desc_pool, gfp_flags, &phys);
-       if (desc) {
-               INIT_LIST_HEAD(&desc->tx_list);
-               dma_async_tx_descriptor_init(&desc->txd, chan);
-               /* txd.flags will be overwritten in prep functions */
-               desc->txd.flags = DMA_CTRL_ACK;
-               desc->txd.tx_submit = atc_tx_submit;
-               desc->txd.phys = phys;
-       }
-
-       return desc;
-}
-
-/**
- * atc_desc_get - get an unused descriptor from free_list
- * @atchan: channel we want a new descriptor for
- */
-static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
-{
-       struct at_desc *desc, *_desc;
-       struct at_desc *ret = NULL;
-       unsigned long flags;
-       unsigned int i = 0;
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
-               i++;
-               if (async_tx_test_ack(&desc->txd)) {
-                       list_del(&desc->desc_node);
-                       ret = desc;
-                       break;
-               }
-               dev_dbg(chan2dev(&atchan->dma_chan),
-                               "desc %p not ACKed\n", desc);
-       }
-       spin_unlock_irqrestore(&atchan->lock, flags);
-       dev_vdbg(chan2dev(&atchan->dma_chan),
-               "scanned %u descriptors on freelist\n", i);
-
-       /* no more descriptor available in initial pool: create one more */
-       if (!ret)
-               ret = atc_alloc_descriptor(&atchan->dma_chan, GFP_NOWAIT);
-
-       return ret;
-}
-
-/**
- * atc_desc_put - move a descriptor, including any children, to the free list
- * @atchan: channel we work on
- * @desc: descriptor, at the head of a chain, to move to free list
- */
-static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
-{
-       if (desc) {
-               struct at_desc *child;
-               unsigned long flags;
-
-               spin_lock_irqsave(&atchan->lock, flags);
-               list_for_each_entry(child, &desc->tx_list, desc_node)
-                       dev_vdbg(chan2dev(&atchan->dma_chan),
-                                       "moving child desc %p to freelist\n",
-                                       child);
-               list_splice_init(&desc->tx_list, &atchan->free_list);
-               dev_vdbg(chan2dev(&atchan->dma_chan),
-                        "moving desc %p to freelist\n", desc);
-               list_add(&desc->desc_node, &atchan->free_list);
-               spin_unlock_irqrestore(&atchan->lock, flags);
-       }
-}
-
-/**
- * atc_desc_chain - build chain adding a descriptor
- * @first: address of first descriptor of the chain
- * @prev: address of previous descriptor of the chain
- * @desc: descriptor to queue
- *
- * Called from prep_* functions
- */
-static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
-                          struct at_desc *desc)
-{
-       if (!(*first)) {
-               *first = desc;
-       } else {
-               /* inform the HW lli about chaining */
-               (*prev)->lli.dscr = desc->txd.phys;
-               /* insert the link descriptor to the LD ring */
-               list_add_tail(&desc->desc_node,
-                               &(*first)->tx_list);
-       }
-       *prev = desc;
+       if (i)
+               desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys;
 }
 
 /**
  * atc_dostart - starts the DMA engine for real
  * @atchan: the channel we want to start
- * @first: first descriptor in the list we want to begin with
- *
- * Called with atchan->lock held and bh disabled
  */
-static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
+static void atc_dostart(struct at_dma_chan *atchan)
 {
-       struct at_dma   *atdma = to_at_dma(atchan->dma_chan.device);
+       struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc);
+       struct at_desc *desc;
 
-       /* ASSERT:  channel is idle */
-       if (atc_chan_is_enabled(atchan)) {
-               dev_err(chan2dev(&atchan->dma_chan),
-                       "BUG: Attempted to start non-idle channel\n");
-               dev_err(chan2dev(&atchan->dma_chan),
-                       "  channel: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
-                       channel_readl(atchan, SADDR),
-                       channel_readl(atchan, DADDR),
-                       channel_readl(atchan, CTRLA),
-                       channel_readl(atchan, CTRLB),
-                       channel_readl(atchan, DSCR));
-
-               /* The tasklet will hopefully advance the queue... */
+       if (!vd) {
+               atchan->desc = NULL;
                return;
        }
 
        vdbg_dump_regs(atchan);
 
+       list_del(&vd->node);
+       atchan->desc = desc = to_atdma_desc(&vd->tx);
+
        channel_writel(atchan, SADDR, 0);
        channel_writel(atchan, DADDR, 0);
        channel_writel(atchan, CTRLA, 0);
        channel_writel(atchan, CTRLB, 0);
-       channel_writel(atchan, DSCR, first->txd.phys);
-       channel_writel(atchan, SPIP, FIELD_PREP(ATC_SPIP_HOLE,
-                                               first->src_hole) |
-                      FIELD_PREP(ATC_SPIP_BOUNDARY, first->boundary));
-       channel_writel(atchan, DPIP, FIELD_PREP(ATC_DPIP_HOLE,
-                                               first->dst_hole) |
-                      FIELD_PREP(ATC_DPIP_BOUNDARY, first->boundary));
+       channel_writel(atchan, DSCR, desc->sg[0].lli_phys);
+       channel_writel(atchan, SPIP,
+                      FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) |
+                      FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary));
+       channel_writel(atchan, DPIP,
+                      FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) |
+                      FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary));
+
        /* Don't allow CPU to reorder channel enable. */
        wmb();
-       dma_writel(atdma, CHER, atchan->mask);
+       dma_writel(atchan->atdma, CHER, atchan->mask);
 
        vdbg_dump_regs(atchan);
 }
 
-/*
- * atc_get_desc_by_cookie - get the descriptor of a cookie
- * @atchan: the DMA channel
- * @cookie: the cookie to get the descriptor for
- */
-static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
-                                               dma_cookie_t cookie)
+static void atdma_desc_free(struct virt_dma_desc *vd)
 {
-       struct at_desc *desc, *_desc;
+       struct at_dma *atdma = to_at_dma(vd->tx.chan->device);
+       struct at_desc *desc = to_atdma_desc(&vd->tx);
+       unsigned int i;
 
-       list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) {
-               if (desc->txd.cookie == cookie)
-                       return desc;
+       for (i = 0; i < desc->sglen; i++) {
+               if (desc->sg[i].lli)
+                       dma_pool_free(atdma->lli_pool, desc->sg[i].lli,
+                                     desc->sg[i].lli_phys);
        }
 
-       list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
-               if (desc->txd.cookie == cookie)
-                       return desc;
+       /* If the transfer was a memset, free our temporary buffer */
+       if (desc->memset_buffer) {
+               dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
+                             desc->memset_paddr);
+               desc->memset_buffer = false;
        }
 
-       return NULL;
+       kfree(desc);
 }
 
 /**
@@ -756,20 +624,19 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
 /**
  * atc_get_llis_residue - Get residue for a hardware linked list transfer
  *
- * Calculate the residue by removing the length of the child descriptors already
- * transferred from the total length. To get the current child descriptor we can
- * use the value of the channel's DSCR register and compare it against the value
- * of the hardware linked list structure of each child descriptor.
+ * Calculate the residue by removing the length of the Linked List Item (LLI)
+ * already transferred from the total length. To get the current LLI we can use
+ * the value of the channel's DSCR register and compare it against the DSCR
+ * value of each LLI.
  *
  * The CTRLA register provides us with the amount of data already read from the
- * source for the current child descriptor. So we can compute a more accurate
- * residue by also removing the number of bytes corresponding to this amount of
- * data.
+ * source for the LLI. So we can compute a more accurate residue by also
+ * removing the number of bytes corresponding to this amount of data.
  *
  * However, the DSCR and CTRLA registers cannot be read both atomically. Hence a
- * race condition may occur: the first read register may refer to one child
- * descriptor whereas the second read may refer to a later child descriptor in
- * the list because of the DMA transfer progression inbetween the two reads.
+ * race condition may occur: the first read register may refer to one LLI
+ * whereas the second read may refer to a later LLI in the list because of the
+ * DMA transfer progression inbetween the two reads.
  *
  * One solution could have been to pause the DMA transfer, read the DSCR and
  * CTRLA then resume the DMA transfer. Nonetheless, this approach presents some
@@ -786,12 +653,11 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
  * Then we'd rather use another solution: the DSCR is read a first time, the
  * CTRLA is read in turn, next the DSCR is read a second time. If the two
  * consecutive read values of the DSCR are the same then we assume both refers
- * to the very same child descriptor as well as the CTRLA value read inbetween
- * does. For cyclic tranfers, the assumption is that a full loop is "not so
- * fast". If the two DSCR values are different, we read again the CTRLA then the
- * DSCR till two consecutive read values from DSCR are equal or till the
- * maximum trials is reach. This algorithm is very unlikely not to find a stable
- * value for DSCR.
+ * to the very same LLI as well as the CTRLA value read inbetween does. For
+ * cyclic tranfers, the assumption is that a full loop is "not so fast". If the
+ * two DSCR values are different, we read again the CTRLA then the DSCR till two
+ * consecutive read values from DSCR are equal or till the maximum trials is
+ * reach. This algorithm is very unlikely not to find a stable value for DSCR.
  * @atchan: pointer to an atmel hdmac channel.
  * @desc: pointer to the descriptor for which the residue is calculated.
  * @residue: residue to be set to dma_tx_state.
@@ -800,7 +666,6 @@ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
 static int atc_get_llis_residue(struct at_dma_chan *atchan,
                                struct at_desc *desc, u32 *residue)
 {
-       struct at_desc *child;
        u32 len, ctrla, dscr;
        unsigned int i;
 
@@ -836,24 +701,25 @@ static int atc_get_llis_residue(struct at_dma_chan *atchan,
                return -ETIMEDOUT;
 
        /* For the first descriptor we can be more accurate. */
-       if (desc->lli.dscr == dscr) {
+       if (desc->sg[0].lli->dscr == dscr) {
                *residue = atc_calc_bytes_left(len, ctrla);
                return 0;
        }
+       len -= desc->sg[0].len;
 
-       len -= desc->len;
-       list_for_each_entry(child, &desc->tx_list, desc_node) {
-               if (child->lli.dscr == dscr)
+       for (i = 1; i < desc->sglen; i++) {
+               if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr)
                        break;
-               len -= child->len;
+               len -= desc->sg[i].len;
        }
 
        /*
-        * For the current descriptor in the chain we can calculate the
-        * remaining bytes using the channel's register.
+        * For the current LLI in the chain we can calculate the remaining bytes
+        * using the channel's CTRLA register.
         */
        *residue = atc_calc_bytes_left(len, ctrla);
        return 0;
+
 }
 
 /**
@@ -867,139 +733,42 @@ static int atc_get_llis_residue(struct at_dma_chan *atchan,
 static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie,
                           u32 *residue)
 {
-       struct at_dma_chan      *atchan = to_at_dma_chan(chan);
-       struct at_desc *desc_first = atc_first_active(atchan);
-       struct at_desc *desc;
+       struct at_dma_chan *atchan = to_at_dma_chan(chan);
+       struct virt_dma_desc *vd;
+       struct at_desc *desc = NULL;
        u32 len, ctrla;
 
-       /*
-        * If the cookie doesn't match to the currently running transfer then
-        * we can return the total length of the associated DMA transfer,
-        * because it is still queued.
-        */
-       desc = atc_get_desc_by_cookie(atchan, cookie);
-       if (desc == NULL)
+       vd = vchan_find_desc(&atchan->vc, cookie);
+       if (vd)
+               desc = to_atdma_desc(&vd->tx);
+       else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie)
+               desc = atchan->desc;
+
+       if (!desc)
                return -EINVAL;
-       else if (desc != desc_first)
-               return desc->total_len;
 
-       if (desc_first->lli.dscr)
+       if (desc->sg[0].lli->dscr)
                /* hardware linked list transfer */
-               return atc_get_llis_residue(atchan, desc_first, residue);
+               return atc_get_llis_residue(atchan, desc, residue);
 
        /* single transfer */
-       len = desc_first->total_len;
+       len = desc->total_len;
        ctrla = channel_readl(atchan, CTRLA);
        *residue = atc_calc_bytes_left(len, ctrla);
        return 0;
 }
 
 /**
- * atc_chain_complete - finish work for one transaction chain
- * @atchan: channel we work on
- * @desc: descriptor at the head of the chain we want do complete
- */
-static void
-atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
-{
-       struct dma_async_tx_descriptor  *txd = &desc->txd;
-       struct at_dma                   *atdma = to_at_dma(atchan->dma_chan.device);
-       unsigned long flags;
-
-       dev_vdbg(chan2dev(&atchan->dma_chan),
-               "descriptor %u complete\n", txd->cookie);
-
-       spin_lock_irqsave(&atchan->lock, flags);
-
-       /* mark the descriptor as complete for non cyclic cases only */
-       if (!atc_chan_is_cyclic(atchan))
-               dma_cookie_complete(txd);
-
-       spin_unlock_irqrestore(&atchan->lock, flags);
-
-       dma_descriptor_unmap(txd);
-       /* for cyclic transfers,
-        * no need to replay callback function while stopping */
-       if (!atc_chan_is_cyclic(atchan))
-               dmaengine_desc_get_callback_invoke(txd, NULL);
-
-       dma_run_dependencies(txd);
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       /* move children to free_list */
-       list_splice_init(&desc->tx_list, &atchan->free_list);
-       /* add myself to free_list */
-       list_add(&desc->desc_node, &atchan->free_list);
-       spin_unlock_irqrestore(&atchan->lock, flags);
-
-       /* If the transfer was a memset, free our temporary buffer */
-       if (desc->memset_buffer) {
-               dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
-                             desc->memset_paddr);
-               desc->memset_buffer = false;
-       }
-}
-
-/**
- * atc_advance_work - at the end of a transaction, move forward
- * @atchan: channel where the transaction ended
- */
-static void atc_advance_work(struct at_dma_chan *atchan)
-{
-       struct at_desc *desc;
-       unsigned long flags;
-
-       dev_vdbg(chan2dev(&atchan->dma_chan), "advance_work\n");
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
-               return spin_unlock_irqrestore(&atchan->lock, flags);
-
-       desc = atc_first_active(atchan);
-       /* Remove the transfer node from the active list. */
-       list_del_init(&desc->desc_node);
-       spin_unlock_irqrestore(&atchan->lock, flags);
-       atc_chain_complete(atchan, desc);
-
-       /* advance work */
-       spin_lock_irqsave(&atchan->lock, flags);
-       if (!list_empty(&atchan->active_list)) {
-               desc = atc_first_queued(atchan);
-               list_move_tail(&desc->desc_node, &atchan->active_list);
-               atc_dostart(atchan, desc);
-       }
-       spin_unlock_irqrestore(&atchan->lock, flags);
-}
-
-
-/**
  * atc_handle_error - handle errors reported by DMA controller
- * @atchan: channel where error occurs
+ * @atchan: channel where error occurs.
+ * @i: channel index
  */
-static void atc_handle_error(struct at_dma_chan *atchan)
+static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i)
 {
-       struct at_desc *bad_desc;
-       struct at_desc *desc;
-       struct at_desc *child;
-       unsigned long flags;
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       /*
-        * The descriptor currently at the head of the active list is
-        * broked. Since we don't have any way to report errors, we'll
-        * just have to scream loudly and try to carry on.
-        */
-       bad_desc = atc_first_active(atchan);
-       list_del_init(&bad_desc->desc_node);
-
-       /* Try to restart the controller */
-       if (!list_empty(&atchan->active_list)) {
-               desc = atc_first_queued(atchan);
-               list_move_tail(&desc->desc_node, &atchan->active_list);
-               atc_dostart(atchan, desc);
-       }
+       struct at_desc *desc = atchan->desc;
 
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       /* Disable channel on AHB error */
+       dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask);
 
        /*
         * KERN_CRITICAL may seem harsh, but since this only happens
@@ -1008,47 +777,37 @@ static void atc_handle_error(struct at_dma_chan *atchan)
         * controller flagged an error instead of scribbling over
         * random memory locations.
         */
-       dev_crit(chan2dev(&atchan->dma_chan),
-                       "Bad descriptor submitted for DMA!\n");
-       dev_crit(chan2dev(&atchan->dma_chan),
-                       "  cookie: %d\n", bad_desc->txd.cookie);
-       atc_dump_lli(atchan, &bad_desc->lli);
-       list_for_each_entry(child, &bad_desc->tx_list, desc_node)
-               atc_dump_lli(atchan, &child->lli);
-
-       /* Pretend the descriptor completed successfully */
-       atc_chain_complete(atchan, bad_desc);
-}
-
-/**
- * atc_handle_cyclic - at the end of a period, run callback function
- * @atchan: channel used for cyclic operations
- */
-static void atc_handle_cyclic(struct at_dma_chan *atchan)
-{
-       struct at_desc                  *first = atc_first_active(atchan);
-       struct dma_async_tx_descriptor  *txd = &first->txd;
-
-       dev_vdbg(chan2dev(&atchan->dma_chan),
-                       "new cyclic period llp 0x%08x\n",
-                       channel_readl(atchan, DSCR));
-
-       dmaengine_desc_get_callback_invoke(txd, NULL);
+       dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n");
+       dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n",
+                desc->vd.tx.cookie);
+       for (i = 0; i < desc->sglen; i++)
+               atc_dump_lli(atchan, desc->sg[i].lli);
 }
 
-/*--  IRQ & Tasklet  ---------------------------------------------------*/
-
-static void atc_tasklet(struct tasklet_struct *t)
+static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending,
+                                  unsigned int i)
 {
-       struct at_dma_chan *atchan = from_tasklet(atchan, t, tasklet);
+       struct at_desc *desc;
 
-       if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
-               return atc_handle_error(atchan);
+       spin_lock(&atchan->vc.lock);
+       desc = atchan->desc;
 
-       if (atc_chan_is_cyclic(atchan))
-               return atc_handle_cyclic(atchan);
+       if (desc) {
+               if (pending & AT_DMA_ERR(i)) {
+                       atc_handle_error(atchan, i);
+                       /* Pretend the descriptor completed successfully */
+               }
 
-       atc_advance_work(atchan);
+               if (atc_chan_is_cyclic(atchan)) {
+                       vchan_cyclic_callback(&desc->vd);
+               } else {
+                       vchan_cookie_complete(&desc->vd);
+                       atchan->desc = NULL;
+                       if (!(atc_chan_is_enabled(atchan)))
+                               atc_dostart(atchan);
+               }
+       }
+       spin_unlock(&atchan->vc.lock);
 }
 
 static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
@@ -1073,17 +832,10 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
 
                for (i = 0; i < atdma->dma_device.chancnt; i++) {
                        atchan = &atdma->chan[i];
-                       if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
-                               if (pending & AT_DMA_ERR(i)) {
-                                       /* Disable channel on AHB error */
-                                       dma_writel(atdma, CHDR,
-                                               AT_DMA_RES(i) | atchan->mask);
-                                       /* Give information to tasklet */
-                                       set_bit(ATC_IS_ERROR, &atchan->status);
-                               }
-                               tasklet_schedule(&atchan->tasklet);
-                               ret = IRQ_HANDLED;
-                       }
+                       if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))))
+                               continue;
+                       atdma_handle_chan_done(atchan, pending, i);
+                       ret = IRQ_HANDLED;
                }
 
        } while (pending);
@@ -1091,35 +843,7 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
        return ret;
 }
 
-
 /*--  DMA Engine API  --------------------------------------------------*/
-
-/**
- * atc_tx_submit - set the prepared descriptor(s) to be executed by the engine
- * @tx: descriptor at the head of the transaction chain
- *
- * Queue chain if DMA engine is working already
- *
- * Cookie increment and adding to active_list or queue must be atomic
- */
-static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx)
-{
-       struct at_desc          *desc = txd_to_at_desc(tx);
-       struct at_dma_chan      *atchan = to_at_dma_chan(tx->chan);
-       dma_cookie_t            cookie;
-       unsigned long           flags;
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       cookie = dma_cookie_assign(tx);
-
-       list_add_tail(&desc->desc_node, &atchan->queue);
-       spin_unlock_irqrestore(&atchan->lock, flags);
-
-       dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
-                desc->txd.cookie);
-       return cookie;
-}
-
 /**
  * atc_prep_dma_interleaved - prepare memory to memory interleaved operation
  * @chan: the channel to prepare operation on
@@ -1131,9 +855,12 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
                         struct dma_interleaved_template *xt,
                         unsigned long flags)
 {
+       struct at_dma           *atdma = to_at_dma(chan->device);
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct data_chunk       *first;
-       struct at_desc          *desc = NULL;
+       struct atdma_sg         *atdma_sg;
+       struct at_desc          *desc;
+       struct at_lli           *lli;
        size_t                  xfer_count;
        unsigned int            dwidth;
        u32                     ctrla;
@@ -1172,8 +899,7 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
                len += chunk->size;
        }
 
-       dwidth = atc_get_xfer_width(xt->src_start,
-                                   xt->dst_start, len);
+       dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len);
 
        xfer_count = len >> dwidth;
        if (xfer_count > ATC_BTSIZE_MAX) {
@@ -1190,32 +916,34 @@ atc_prep_dma_interleaved(struct dma_chan *chan,
                ATC_SRC_PIP | ATC_DST_PIP |
                FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);
 
-       /* create the transfer */
-       desc = atc_desc_get(atchan);
-       if (!desc) {
-               dev_err(chan2dev(chan),
-                       "%s: couldn't allocate our descriptor\n", __func__);
+       desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
+       if (!desc)
+               return NULL;
+       desc->sglen = 1;
+
+       atdma_sg = desc->sg;
+       atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+                                      &atdma_sg->lli_phys);
+       if (!atdma_sg->lli) {
+               kfree(desc);
                return NULL;
        }
+       lli = atdma_sg->lli;
 
-       desc->lli.saddr = xt->src_start;
-       desc->lli.daddr = xt->dst_start;
-       desc->lli.ctrla = ctrla | xfer_count;
-       desc->lli.ctrlb = ctrlb;
+       lli->saddr = xt->src_start;
+       lli->daddr = xt->dst_start;
+       lli->ctrla = ctrla | xfer_count;
+       lli->ctrlb = ctrlb;
 
        desc->boundary = first->size >> dwidth;
        desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1;
        desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1;
 
-       desc->txd.cookie = -EBUSY;
-       desc->total_len = desc->len = len;
-
-       /* set end-of-link to the last link descriptor of list*/
-       set_desc_eol(desc);
-
-       desc->txd.flags = flags; /* client is in control of this ack */
+       atdma_sg->len = len;
+       desc->total_len = len;
 
-       return &desc->txd;
+       set_lli_eol(desc, 0);
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 }
 
 /**
@@ -1230,25 +958,32 @@ static struct dma_async_tx_descriptor *
 atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
                size_t len, unsigned long flags)
 {
+       struct at_dma           *atdma = to_at_dma(chan->device);
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_desc          *desc = NULL;
-       struct at_desc          *first = NULL;
-       struct at_desc          *prev = NULL;
        size_t                  xfer_count;
        size_t                  offset;
+       size_t                  sg_len;
        unsigned int            src_width;
        unsigned int            dst_width;
+       unsigned int            i;
        u32                     ctrla;
        u32                     ctrlb;
 
-       dev_vdbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
-                       &dest, &src, len, flags);
+       dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
+               &dest, &src, len, flags);
 
        if (unlikely(!len)) {
-               dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
+               dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
                return NULL;
        }
 
+       sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX);
+       desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+       if (!desc)
+               return NULL;
+       desc->sglen = sg_len;
+
        ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
                FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
                FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
@@ -1263,50 +998,49 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
        ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) |
                FIELD_PREP(ATC_DST_WIDTH, dst_width);
 
-       for (offset = 0; offset < len; offset += xfer_count << src_width) {
-               xfer_count = min_t(size_t, (len - offset) >> src_width,
-                               ATC_BTSIZE_MAX);
+       for (offset = 0, i = 0; offset < len;
+            offset += xfer_count << src_width, i++) {
+               struct atdma_sg *atdma_sg = &desc->sg[i];
+               struct at_lli *lli;
 
-               desc = atc_desc_get(atchan);
-               if (!desc)
+               atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+                                              &atdma_sg->lli_phys);
+               if (!atdma_sg->lli)
                        goto err_desc_get;
+               lli = atdma_sg->lli;
+
+               xfer_count = min_t(size_t, (len - offset) >> src_width,
+                                  ATC_BTSIZE_MAX);
 
-               desc->lli.saddr = src + offset;
-               desc->lli.daddr = dest + offset;
-               desc->lli.ctrla = ctrla | xfer_count;
-               desc->lli.ctrlb = ctrlb;
+               lli->saddr = src + offset;
+               lli->daddr = dest + offset;
+               lli->ctrla = ctrla | xfer_count;
+               lli->ctrlb = ctrlb;
 
-               desc->txd.cookie = 0;
-               desc->len = xfer_count << src_width;
+               desc->sg[i].len = xfer_count << src_width;
 
-               atc_desc_chain(&first, &prev, desc);
+               atdma_lli_chain(desc, i);
        }
 
-       /* First descriptor of the chain embedds additional information */
-       first->txd.cookie = -EBUSY;
-       first->total_len = len;
+       desc->total_len = len;
 
        /* set end-of-link to the last link descriptor of list*/
-       set_desc_eol(desc);
-
-       first->txd.flags = flags; /* client is in control of this ack */
+       set_lli_eol(desc, i - 1);
 
-       return &first->txd;
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 
 err_desc_get:
-       atc_desc_put(atchan, first);
+       atdma_desc_free(&desc->vd);
        return NULL;
 }
 
-static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
-                                             dma_addr_t psrc,
-                                             dma_addr_t pdst,
-                                             size_t len)
+static int atdma_create_memset_lli(struct dma_chan *chan,
+                                  struct atdma_sg *atdma_sg,
+                                  dma_addr_t psrc, dma_addr_t pdst, size_t len)
 {
-       struct at_dma_chan *atchan = to_at_dma_chan(chan);
-       struct at_desc *desc;
+       struct at_dma *atdma = to_at_dma(chan->device);
+       struct at_lli *lli;
        size_t xfer_count;
-
        u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2);
        u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
                    FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) |
@@ -1315,27 +1049,24 @@ static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
 
        xfer_count = len >> 2;
        if (xfer_count > ATC_BTSIZE_MAX) {
-               dev_err(chan2dev(chan), "%s: buffer is too big\n",
-                       __func__);
-               return NULL;
+               dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__);
+               return -EINVAL;
        }
 
-       desc = atc_desc_get(atchan);
-       if (!desc) {
-               dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
-                       __func__);
-               return NULL;
-       }
+       atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
+                                      &atdma_sg->lli_phys);
+       if (!atdma_sg->lli)
+               return -ENOMEM;
+       lli = atdma_sg->lli;
 
-       desc->lli.saddr = psrc;
-       desc->lli.daddr = pdst;
-       desc->lli.ctrla = ctrla | xfer_count;
-       desc->lli.ctrlb = ctrlb;
+       lli->saddr = psrc;
+       lli->daddr = pdst;
+       lli->ctrla = ctrla | xfer_count;
+       lli->ctrlb = ctrlb;
 
-       desc->txd.cookie = 0;
-       desc->len = len;
+       atdma_sg->len = len;
 
-       return desc;
+       return 0;
 }
 
 /**
@@ -1350,11 +1081,13 @@ static struct dma_async_tx_descriptor *
 atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
                    size_t len, unsigned long flags)
 {
+       struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
        struct at_desc          *desc;
        void __iomem            *vaddr;
        dma_addr_t              paddr;
        char                    fill_pattern;
+       int                     ret;
 
        dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__,
                &dest, value, len, flags);
@@ -1385,27 +1118,28 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
                       (fill_pattern << 8) |
                       fill_pattern;
 
-       desc = atc_create_memset_desc(chan, paddr, dest, len);
-       if (!desc) {
-               dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
-                       __func__);
+       desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
+       if (!desc)
                goto err_free_buffer;
-       }
+       desc->sglen = 1;
+
+       ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len);
+       if (ret)
+               goto err_free_desc;
 
        desc->memset_paddr = paddr;
        desc->memset_vaddr = vaddr;
        desc->memset_buffer = true;
 
-       desc->txd.cookie = -EBUSY;
        desc->total_len = len;
 
        /* set end-of-link on the descriptor */
-       set_desc_eol(desc);
-
-       desc->txd.flags = flags;
+       set_lli_eol(desc, 0);
 
-       return &desc->txd;
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 
+err_free_desc:
+       kfree(desc);
 err_free_buffer:
        dma_pool_free(atdma->memset_pool, vaddr, paddr);
        return NULL;
@@ -1419,12 +1153,13 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
-       struct at_desc          *desc = NULL, *first = NULL, *prev = NULL;
+       struct at_desc          *desc;
        struct scatterlist      *sg;
        void __iomem            *vaddr;
        dma_addr_t              paddr;
        size_t                  total_len = 0;
        int                     i;
+       int                     ret;
 
        dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
                 value, sg_len, flags);
@@ -1443,6 +1178,11 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
        }
        *(u32*)vaddr = value;
 
+       desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+       if (!desc)
+               goto err_free_dma_buf;
+       desc->sglen = sg_len;
+
        for_each_sg(sgl, sg, sg_len, i) {
                dma_addr_t dest = sg_dma_address(sg);
                size_t len = sg_dma_len(sg);
@@ -1453,38 +1193,33 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
                if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
                        dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
                                __func__);
-                       goto err_put_desc;
+                       goto err_free_desc;
                }
 
-               desc = atc_create_memset_desc(chan, paddr, dest, len);
-               if (!desc)
-                       goto err_put_desc;
-
-               atc_desc_chain(&first, &prev, desc);
+               ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest,
+                                             len);
+               if (ret)
+                       goto err_free_desc;
 
+               atdma_lli_chain(desc, i);
                total_len += len;
        }
 
-       /*
-        * Only set the buffer pointers on the last descriptor to
-        * avoid free'ing while we have our transfer still going
-        */
        desc->memset_paddr = paddr;
        desc->memset_vaddr = vaddr;
        desc->memset_buffer = true;
 
-       first->txd.cookie = -EBUSY;
-       first->total_len = total_len;
+       desc->total_len = total_len;
 
        /* set end-of-link on the descriptor */
-       set_desc_eol(desc);
-
-       first->txd.flags = flags;
+       set_lli_eol(desc, i - 1);
 
-       return &first->txd;
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 
-err_put_desc:
-       atc_desc_put(atchan, first);
+err_free_desc:
+       atdma_desc_free(&desc->vd);
+err_free_dma_buf:
+       dma_pool_free(atdma->memset_pool, vaddr, paddr);
        return NULL;
 }
 
@@ -1502,11 +1237,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                unsigned int sg_len, enum dma_transfer_direction direction,
                unsigned long flags, void *context)
 {
+       struct at_dma           *atdma = to_at_dma(chan->device);
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma_slave     *atslave = chan->private;
        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
-       struct at_desc          *first = NULL;
-       struct at_desc          *prev = NULL;
+       struct at_desc          *desc;
        u32                     ctrla;
        u32                     ctrlb;
        dma_addr_t              reg;
@@ -1526,6 +1261,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                return NULL;
        }
 
+       desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
+       if (!desc)
+               return NULL;
+       desc->sglen = sg_len;
+
        ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
                FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst);
        ctrlb = ATC_IEN;
@@ -1542,13 +1282,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                         FIELD_PREP(ATC_DIF, atchan->per_if);
                reg = sconfig->dst_addr;
                for_each_sg(sgl, sg, sg_len, i) {
-                       struct at_desc  *desc;
+                       struct atdma_sg *atdma_sg = &desc->sg[i];
+                       struct at_lli *lli;
                        u32             len;
                        u32             mem;
 
-                       desc = atc_desc_get(atchan);
-                       if (!desc)
+                       atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
+                                                      GFP_NOWAIT,
+                                                      &atdma_sg->lli_phys);
+                       if (!atdma_sg->lli)
                                goto err_desc_get;
+                       lli = atdma_sg->lli;
 
                        mem = sg_dma_address(sg);
                        len = sg_dma_len(sg);
@@ -1561,16 +1305,18 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                        if (unlikely(mem & 3 || len & 3))
                                mem_width = 0;
 
-                       desc->lli.saddr = mem;
-                       desc->lli.daddr = reg;
-                       desc->lli.ctrla = ctrla |
-                                         FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
-                                         len >> mem_width;
-                       desc->lli.ctrlb = ctrlb;
-                       desc->len = len;
+                       lli->saddr = mem;
+                       lli->daddr = reg;
+                       lli->ctrla = ctrla |
+                                    FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
+                                    len >> mem_width;
+                       lli->ctrlb = ctrlb;
 
-                       atc_desc_chain(&first, &prev, desc);
+                       atdma_sg->len = len;
                        total_len += len;
+
+                       desc->sg[i].len = len;
+                       atdma_lli_chain(desc, i);
                }
                break;
        case DMA_DEV_TO_MEM:
@@ -1585,13 +1331,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
                reg = sconfig->src_addr;
                for_each_sg(sgl, sg, sg_len, i) {
-                       struct at_desc  *desc;
+                       struct atdma_sg *atdma_sg = &desc->sg[i];
+                       struct at_lli *lli;
                        u32             len;
                        u32             mem;
 
-                       desc = atc_desc_get(atchan);
-                       if (!desc)
+                       atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
+                                                      GFP_NOWAIT,
+                                                      &atdma_sg->lli_phys);
+                       if (!atdma_sg->lli)
                                goto err_desc_get;
+                       lli = atdma_sg->lli;
 
                        mem = sg_dma_address(sg);
                        len = sg_dma_len(sg);
@@ -1604,16 +1354,17 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                        if (unlikely(mem & 3 || len & 3))
                                mem_width = 0;
 
-                       desc->lli.saddr = reg;
-                       desc->lli.daddr = mem;
-                       desc->lli.ctrla = ctrla |
-                                         FIELD_PREP(ATC_DST_WIDTH, mem_width) |
-                                         len >> reg_width;
-                       desc->lli.ctrlb = ctrlb;
-                       desc->len = len;
+                       lli->saddr = reg;
+                       lli->daddr = mem;
+                       lli->ctrla = ctrla |
+                                    FIELD_PREP(ATC_DST_WIDTH, mem_width) |
+                                    len >> reg_width;
+                       lli->ctrlb = ctrlb;
 
-                       atc_desc_chain(&first, &prev, desc);
+                       desc->sg[i].len = len;
                        total_len += len;
+
+                       atdma_lli_chain(desc, i);
                }
                break;
        default:
@@ -1621,21 +1372,16 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
        }
 
        /* set end-of-link to the last link descriptor of list*/
-       set_desc_eol(prev);
-
-       /* First descriptor of the chain embedds additional information */
-       first->txd.cookie = -EBUSY;
-       first->total_len = total_len;
+       set_lli_eol(desc, i - 1);
 
-       /* first link descriptor of list is responsible of flags */
-       first->txd.flags = flags; /* client is in control of this ack */
+       desc->total_len = total_len;
 
-       return &first->txd;
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 
 err_desc_get:
        dev_err(chan2dev(chan), "not enough descriptors available\n");
 err:
-       atc_desc_put(atchan, first);
+       atdma_desc_free(&desc->vd);
        return NULL;
 }
 
@@ -1665,54 +1411,59 @@ err_out:
  */
 static int
 atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
-               unsigned int period_index, dma_addr_t buf_addr,
+               unsigned int i, dma_addr_t buf_addr,
                unsigned int reg_width, size_t period_len,
                enum dma_transfer_direction direction)
 {
+       struct at_dma           *atdma = to_at_dma(chan->device);
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
-       u32                     ctrla;
+       struct atdma_sg         *atdma_sg = &desc->sg[i];
+       struct at_lli           *lli;
 
-       /* prepare common CRTLA value */
-       ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
-               FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
-               FIELD_PREP(ATC_DST_WIDTH, reg_width) |
-               FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
-               period_len >> reg_width;
+       atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC,
+                                      &atdma_sg->lli_phys);
+       if (!atdma_sg->lli)
+               return -ENOMEM;
+       lli = atdma_sg->lli;
 
        switch (direction) {
        case DMA_MEM_TO_DEV:
-               desc->lli.saddr = buf_addr + (period_len * period_index);
-               desc->lli.daddr = sconfig->dst_addr;
-               desc->lli.ctrla = ctrla;
-               desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
-                                            ATC_DST_ADDR_MODE_FIXED) |
-                                 FIELD_PREP(ATC_SRC_ADDR_MODE,
-                                            ATC_SRC_ADDR_MODE_INCR) |
-                                 FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
-                                 FIELD_PREP(ATC_SIF, atchan->mem_if) |
-                                 FIELD_PREP(ATC_DIF, atchan->per_if);
-               desc->len = period_len;
+               lli->saddr = buf_addr + (period_len * i);
+               lli->daddr = sconfig->dst_addr;
+               lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+                                       ATC_DST_ADDR_MODE_FIXED) |
+                            FIELD_PREP(ATC_SRC_ADDR_MODE,
+                                       ATC_SRC_ADDR_MODE_INCR) |
+                            FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
+                            FIELD_PREP(ATC_SIF, atchan->mem_if) |
+                            FIELD_PREP(ATC_DIF, atchan->per_if);
+
                break;
 
        case DMA_DEV_TO_MEM:
-               desc->lli.saddr = sconfig->src_addr;
-               desc->lli.daddr = buf_addr + (period_len * period_index);
-               desc->lli.ctrla = ctrla;
-               desc->lli.ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
-                                            ATC_DST_ADDR_MODE_INCR) |
-                                 FIELD_PREP(ATC_SRC_ADDR_MODE,
-                                            ATC_SRC_ADDR_MODE_FIXED) |
-                                 FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
-                                 FIELD_PREP(ATC_SIF, atchan->per_if) |
-                                 FIELD_PREP(ATC_DIF, atchan->mem_if);
-               desc->len = period_len;
+               lli->saddr = sconfig->src_addr;
+               lli->daddr = buf_addr + (period_len * i);
+               lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
+                                       ATC_DST_ADDR_MODE_INCR) |
+                            FIELD_PREP(ATC_SRC_ADDR_MODE,
+                                       ATC_SRC_ADDR_MODE_FIXED) |
+                            FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
+                            FIELD_PREP(ATC_SIF, atchan->per_if) |
+                            FIELD_PREP(ATC_DIF, atchan->mem_if);
                break;
 
        default:
                return -EINVAL;
        }
 
+       lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
+                    FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
+                    FIELD_PREP(ATC_DST_WIDTH, reg_width) |
+                    FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
+                    period_len >> reg_width;
+       desc->sg[i].len = period_len;
+
        return 0;
 }
 
@@ -1733,8 +1484,7 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma_slave     *atslave = chan->private;
        struct dma_slave_config *sconfig = &atchan->dma_sconfig;
-       struct at_desc          *first = NULL;
-       struct at_desc          *prev = NULL;
+       struct at_desc          *desc;
        unsigned long           was_cyclic;
        unsigned int            reg_width;
        unsigned int            periods = buf_len / period_len;
@@ -1768,33 +1518,26 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
        if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
                goto err_out;
 
+       desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC);
+       if (!desc)
+               goto err_out;
+       desc->sglen = periods;
+
        /* build cyclic linked list */
        for (i = 0; i < periods; i++) {
-               struct at_desc  *desc;
-
-               desc = atc_desc_get(atchan);
-               if (!desc)
-                       goto err_desc_get;
-
                if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
                                             reg_width, period_len, direction))
-                       goto err_desc_get;
-
-               atc_desc_chain(&first, &prev, desc);
+                       goto err_fill_desc;
+               atdma_lli_chain(desc, i);
        }
-
+       desc->total_len = buf_len;
        /* lets make a cyclic list */
-       prev->lli.dscr = first->txd.phys;
-
-       /* First descriptor of the chain embedds additional information */
-       first->txd.cookie = -EBUSY;
-       first->total_len = buf_len;
+       desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys;
 
-       return &first->txd;
+       return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
 
-err_desc_get:
-       dev_err(chan2dev(chan), "not enough descriptors available\n");
-       atc_desc_put(atchan, first);
+err_fill_desc:
+       atdma_desc_free(&desc->vd);
 err_out:
        clear_bit(ATC_IS_CYCLIC, &atchan->status);
        return NULL;
@@ -1823,17 +1566,17 @@ static int atc_pause(struct dma_chan *chan)
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
-       int                     chan_id = atchan->dma_chan.chan_id;
+       int                     chan_id = atchan->vc.chan.chan_id;
        unsigned long           flags;
 
        dev_vdbg(chan2dev(chan), "%s\n", __func__);
 
-       spin_lock_irqsave(&atchan->lock, flags);
+       spin_lock_irqsave(&atchan->vc.lock, flags);
 
        dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
        set_bit(ATC_IS_PAUSED, &atchan->status);
 
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       spin_unlock_irqrestore(&atchan->vc.lock, flags);
 
        return 0;
 }
@@ -1842,7 +1585,7 @@ static int atc_resume(struct dma_chan *chan)
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
-       int                     chan_id = atchan->dma_chan.chan_id;
+       int                     chan_id = atchan->vc.chan.chan_id;
        unsigned long           flags;
 
        dev_vdbg(chan2dev(chan), "%s\n", __func__);
@@ -1850,12 +1593,12 @@ static int atc_resume(struct dma_chan *chan)
        if (!atc_chan_is_paused(atchan))
                return 0;
 
-       spin_lock_irqsave(&atchan->lock, flags);
+       spin_lock_irqsave(&atchan->vc.lock, flags);
 
        dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
        clear_bit(ATC_IS_PAUSED, &atchan->status);
 
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       spin_unlock_irqrestore(&atchan->vc.lock, flags);
 
        return 0;
 }
@@ -1864,9 +1607,11 @@ static int atc_terminate_all(struct dma_chan *chan)
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
-       int                     chan_id = atchan->dma_chan.chan_id;
+       int                     chan_id = atchan->vc.chan.chan_id;
        unsigned long           flags;
 
+       LIST_HEAD(list);
+
        dev_vdbg(chan2dev(chan), "%s\n", __func__);
 
        /*
@@ -1875,7 +1620,7 @@ static int atc_terminate_all(struct dma_chan *chan)
         * channel. We still have to poll the channel enable bit due
         * to AHB/HSB limitations.
         */
-       spin_lock_irqsave(&atchan->lock, flags);
+       spin_lock_irqsave(&atchan->vc.lock, flags);
 
        /* disabling channel: must also remove suspend state */
        dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
@@ -1884,15 +1629,20 @@ static int atc_terminate_all(struct dma_chan *chan)
        while (dma_readl(atdma, CHSR) & atchan->mask)
                cpu_relax();
 
-       /* active_list entries will end up before queued entries */
-       list_splice_tail_init(&atchan->queue, &atchan->free_list);
-       list_splice_tail_init(&atchan->active_list, &atchan->free_list);
+       if (atchan->desc) {
+               vchan_terminate_vdesc(&atchan->desc->vd);
+               atchan->desc = NULL;
+       }
+
+       vchan_get_all_descriptors(&atchan->vc, &list);
 
        clear_bit(ATC_IS_PAUSED, &atchan->status);
        /* if channel dedicated to cyclic operations, free it */
        clear_bit(ATC_IS_CYCLIC, &atchan->status);
 
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       spin_unlock_irqrestore(&atchan->vc.lock, flags);
+
+       vchan_dma_desc_free_list(&atchan->vc, &list);
 
        return 0;
 }
@@ -1922,9 +1672,10 @@ atc_tx_status(struct dma_chan *chan,
        if (dma_status == DMA_COMPLETE || !txstate)
                return dma_status;
 
-       spin_lock_irqsave(&atchan->lock, flags);
+       spin_lock_irqsave(&atchan->vc.lock, flags);
+       /*  Get number of bytes left in the active transactions */
        ret = atc_get_residue(chan, cookie, &residue);
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       spin_unlock_irqrestore(&atchan->vc.lock, flags);
 
        if (unlikely(ret < 0)) {
                dev_vdbg(chan2dev(chan), "get residual bytes error\n");
@@ -1939,27 +1690,17 @@ atc_tx_status(struct dma_chan *chan,
        return dma_status;
 }
 
-/**
- * atc_issue_pending - takes the first transaction descriptor in the pending
- * queue and starts the transfer.
- * @chan: target DMA channel
- */
 static void atc_issue_pending(struct dma_chan *chan)
 {
        struct at_dma_chan *atchan = to_at_dma_chan(chan);
-       struct at_desc *desc;
        unsigned long flags;
 
-       dev_vdbg(chan2dev(chan), "issue_pending\n");
-
-       spin_lock_irqsave(&atchan->lock, flags);
-       if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue))
-               return spin_unlock_irqrestore(&atchan->lock, flags);
-
-       desc = atc_first_queued(atchan);
-       list_move_tail(&desc->desc_node, &atchan->active_list);
-       atc_dostart(atchan, desc);
-       spin_unlock_irqrestore(&atchan->lock, flags);
+       spin_lock_irqsave(&atchan->vc.lock, flags);
+       if (vchan_issue_pending(&atchan->vc) && !atchan->desc) {
+               if (!(atc_chan_is_enabled(atchan)))
+                       atc_dostart(atchan);
+       }
+       spin_unlock_irqrestore(&atchan->vc.lock, flags);
 }
 
 /**
@@ -1972,9 +1713,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
        struct at_dma           *atdma = to_at_dma(chan->device);
-       struct at_desc          *desc;
        struct at_dma_slave     *atslave;
-       int                     i;
        u32                     cfg;
 
        dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
@@ -1985,11 +1724,6 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
                return -EIO;
        }
 
-       if (!list_empty(&atchan->free_list)) {
-               dev_dbg(chan2dev(chan), "can't allocate channel resources (channel not freed from a previous use)\n");
-               return -EIO;
-       }
-
        cfg = ATC_DEFAULT_CFG;
 
        atslave = chan->private;
@@ -2005,26 +1739,10 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
                        cfg = atslave->cfg;
        }
 
-       /* Allocate initial pool of descriptors */
-       for (i = 0; i < init_nr_desc_per_channel; i++) {
-               desc = atc_alloc_descriptor(chan, GFP_KERNEL);
-               if (!desc) {
-                       dev_err(atdma->dma_device.dev,
-                               "Only %d initial descriptors\n", i);
-                       break;
-               }
-               list_add_tail(&desc->desc_node, &atchan->free_list);
-       }
-
-       dma_cookie_init(chan);
-
        /* channel parameters */
        channel_writel(atchan, CFG, cfg);
 
-       dev_dbg(chan2dev(chan),
-               "alloc_chan_resources: allocated %d descriptors\n", i);
-
-       return i;
+       return 0;
 }
 
 /**
@@ -2034,22 +1752,10 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 static void atc_free_chan_resources(struct dma_chan *chan)
 {
        struct at_dma_chan      *atchan = to_at_dma_chan(chan);
-       struct at_dma           *atdma = to_at_dma(chan->device);
-       struct at_desc          *desc, *_desc;
-       LIST_HEAD(list);
 
-       /* ASSERT:  channel is idle */
-       BUG_ON(!list_empty(&atchan->active_list));
-       BUG_ON(!list_empty(&atchan->queue));
        BUG_ON(atc_chan_is_enabled(atchan));
 
-       list_for_each_entry_safe(desc, _desc, &atchan->free_list, desc_node) {
-               dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
-               list_del(&desc->desc_node);
-               /* free link descriptor */
-               dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
-       }
-       list_splice_init(&atchan->free_list, &list);
+       vchan_free_chan_resources(to_virt_chan(chan));
        atchan->status = 0;
 
        /*
@@ -2274,11 +1980,11 @@ static int __init at_dma_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, atdma);
 
        /* create a pool of consistent memory blocks for hardware descriptors */
-       atdma->dma_desc_pool = dma_pool_create("at_hdmac_desc_pool",
-                       &pdev->dev, sizeof(struct at_desc),
-                       4 /* word alignment */, 0);
-       if (!atdma->dma_desc_pool) {
-               dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
+       atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool",
+                                         &pdev->dev, sizeof(struct at_lli),
+                                         4 /* word alignment */, 0);
+       if (!atdma->lli_pool) {
+               dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n");
                err = -ENOMEM;
                goto err_desc_pool_create;
        }
@@ -2303,20 +2009,13 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
                atchan->mem_if = AT_DMA_MEM_IF;
                atchan->per_if = AT_DMA_PER_IF;
-               atchan->dma_chan.device = &atdma->dma_device;
-               dma_cookie_init(&atchan->dma_chan);
-               list_add_tail(&atchan->dma_chan.device_node,
-                               &atdma->dma_device.channels);
 
                atchan->ch_regs = atdma->regs + ch_regs(i);
-               spin_lock_init(&atchan->lock);
                atchan->mask = 1 << i;
 
-               INIT_LIST_HEAD(&atchan->active_list);
-               INIT_LIST_HEAD(&atchan->queue);
-               INIT_LIST_HEAD(&atchan->free_list);
-
-               tasklet_setup(&atchan->tasklet, atc_tasklet);
+               atchan->atdma = atdma;
+               atchan->vc.desc_free = atdma_desc_free;
+               vchan_init(&atchan->vc, &atdma->dma_device);
                atc_enable_chan_irq(atdma, i);
        }
 
@@ -2390,7 +2089,7 @@ err_of_dma_controller_register:
 err_dma_async_device_register:
        dma_pool_destroy(atdma->memset_pool);
 err_memset_pool_create:
-       dma_pool_destroy(atdma->dma_desc_pool);
+       dma_pool_destroy(atdma->lli_pool);
 err_desc_pool_create:
        free_irq(platform_get_irq(pdev, 0), atdma);
 err_irq:
@@ -2409,17 +2108,13 @@ static int at_dma_remove(struct platform_device *pdev)
        dma_async_device_unregister(&atdma->dma_device);
 
        dma_pool_destroy(atdma->memset_pool);
-       dma_pool_destroy(atdma->dma_desc_pool);
+       dma_pool_destroy(atdma->lli_pool);
        free_irq(platform_get_irq(pdev, 0), atdma);
 
        list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
                        device_node) {
-               struct at_dma_chan      *atchan = to_at_dma_chan(chan);
-
                /* Disable interrupts */
                atc_disable_chan_irq(atdma, chan->chan_id);
-
-               tasklet_kill(&atchan->tasklet);
                list_del(&chan->device_node);
        }
 
@@ -2453,7 +2148,7 @@ static int at_dma_prepare(struct device *dev)
 
 static void atc_suspend_cyclic(struct at_dma_chan *atchan)
 {
-       struct dma_chan *chan = &atchan->dma_chan;
+       struct dma_chan *chan = &atchan->vc.chan;
 
        /* Channel should be paused by user
         * do it anyway even if it is not done already */
@@ -2494,7 +2189,7 @@ static int at_dma_suspend_noirq(struct device *dev)
 
 static void atc_resume_cyclic(struct at_dma_chan *atchan)
 {
-       struct at_dma   *atdma = to_at_dma(atchan->dma_chan.device);
+       struct at_dma   *atdma = to_at_dma(atchan->vc.chan.device);
 
        /* restore channel status for cyclic descriptors list:
         * next descriptor in the cyclic list at the time of suspend */
@@ -2568,5 +2263,6 @@ module_exit(at_dma_exit);
 
 MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
+MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:at_hdmac");