include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[safe/jmp/linux-2.6] / drivers / dma / fsldma.c
index 507b297..88f470f 100644 (file)
@@ -27,6 +27,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/dmaengine.h>
 #include <linux/delay.h>
 #include <asm/fsldma.h>
 #include "fsldma.h"
 
-static void dma_init(struct fsldma_chan *fsl_chan)
+static void dma_init(struct fsldma_chan *chan)
 {
        /* Reset the channel */
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, 0, 32);
+       DMA_OUT(chan, &chan->regs->mr, 0, 32);
 
-       switch (fsl_chan->feature & FSL_DMA_IP_MASK) {
+       switch (chan->feature & FSL_DMA_IP_MASK) {
        case FSL_DMA_IP_85XX:
                /* Set the channel to below modes:
                 * EIE - Error interrupt enable
                 * EOSIE - End of segments interrupt enable (basic mode)
                 * EOLNIE - End of links interrupt enable
                 */
-               DMA_OUT(fsl_chan, &fsl_chan->regs->mr, FSL_DMA_MR_EIE
+               DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EIE
                                | FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
                break;
        case FSL_DMA_IP_83XX:
@@ -57,172 +58,146 @@ static void dma_init(struct fsldma_chan *fsl_chan)
                 * EOTIE - End-of-transfer interrupt enable
                 * PRC_RM - PCI read multiple
                 */
-               DMA_OUT(fsl_chan, &fsl_chan->regs->mr, FSL_DMA_MR_EOTIE
+               DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
                                | FSL_DMA_MR_PRC_RM, 32);
                break;
        }
-
 }
 
-static void set_sr(struct fsldma_chan *fsl_chan, u32 val)
+static void set_sr(struct fsldma_chan *chan, u32 val)
 {
-       DMA_OUT(fsl_chan, &fsl_chan->regs->sr, val, 32);
+       DMA_OUT(chan, &chan->regs->sr, val, 32);
 }
 
-static u32 get_sr(struct fsldma_chan *fsl_chan)
+static u32 get_sr(struct fsldma_chan *chan)
 {
-       return DMA_IN(fsl_chan, &fsl_chan->regs->sr, 32);
+       return DMA_IN(chan, &chan->regs->sr, 32);
 }
 
-static void set_desc_cnt(struct fsldma_chan *fsl_chan,
+static void set_desc_cnt(struct fsldma_chan *chan,
                                struct fsl_dma_ld_hw *hw, u32 count)
 {
-       hw->count = CPU_TO_DMA(fsl_chan, count, 32);
+       hw->count = CPU_TO_DMA(chan, count, 32);
 }
 
-static void set_desc_src(struct fsldma_chan *fsl_chan,
+static void set_desc_src(struct fsldma_chan *chan,
                                struct fsl_dma_ld_hw *hw, dma_addr_t src)
 {
        u64 snoop_bits;
 
-       snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+       snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
                ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
-       hw->src_addr = CPU_TO_DMA(fsl_chan, snoop_bits | src, 64);
+       hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
 }
 
-static void set_desc_dst(struct fsldma_chan *fsl_chan,
+static void set_desc_dst(struct fsldma_chan *chan,
                                struct fsl_dma_ld_hw *hw, dma_addr_t dst)
 {
        u64 snoop_bits;
 
-       snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+       snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
                ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
-       hw->dst_addr = CPU_TO_DMA(fsl_chan, snoop_bits | dst, 64);
+       hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
 }
 
-static void set_desc_next(struct fsldma_chan *fsl_chan,
+static void set_desc_next(struct fsldma_chan *chan,
                                struct fsl_dma_ld_hw *hw, dma_addr_t next)
 {
        u64 snoop_bits;
 
-       snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+       snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
                ? FSL_DMA_SNEN : 0;
-       hw->next_ln_addr = CPU_TO_DMA(fsl_chan, snoop_bits | next, 64);
-}
-
-static void set_cdar(struct fsldma_chan *fsl_chan, dma_addr_t addr)
-{
-       DMA_OUT(fsl_chan, &fsl_chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
+       hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
 }
 
-static dma_addr_t get_cdar(struct fsldma_chan *fsl_chan)
+static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
 {
-       return DMA_IN(fsl_chan, &fsl_chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
+       DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
 }
 
-static void set_ndar(struct fsldma_chan *fsl_chan, dma_addr_t addr)
+static dma_addr_t get_cdar(struct fsldma_chan *chan)
 {
-       DMA_OUT(fsl_chan, &fsl_chan->regs->ndar, addr, 64);
+       return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
 }
 
-static dma_addr_t get_ndar(struct fsldma_chan *fsl_chan)
+static dma_addr_t get_ndar(struct fsldma_chan *chan)
 {
-       return DMA_IN(fsl_chan, &fsl_chan->regs->ndar, 64);
+       return DMA_IN(chan, &chan->regs->ndar, 64);
 }
 
-static u32 get_bcr(struct fsldma_chan *fsl_chan)
+static u32 get_bcr(struct fsldma_chan *chan)
 {
-       return DMA_IN(fsl_chan, &fsl_chan->regs->bcr, 32);
+       return DMA_IN(chan, &chan->regs->bcr, 32);
 }
 
-static int dma_is_idle(struct fsldma_chan *fsl_chan)
+static int dma_is_idle(struct fsldma_chan *chan)
 {
-       u32 sr = get_sr(fsl_chan);
+       u32 sr = get_sr(chan);
        return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
 }
 
-static void dma_start(struct fsldma_chan *fsl_chan)
+static void dma_start(struct fsldma_chan *chan)
 {
        u32 mode;
 
-       mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
+       mode = DMA_IN(chan, &chan->regs->mr, 32);
 
-       if ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
-               if (fsl_chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
-                       DMA_OUT(fsl_chan, &fsl_chan->regs->bcr, 0, 32);
+       if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+               if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
+                       DMA_OUT(chan, &chan->regs->bcr, 0, 32);
                        mode |= FSL_DMA_MR_EMP_EN;
                } else {
                        mode &= ~FSL_DMA_MR_EMP_EN;
                }
        }
 
-       if (fsl_chan->feature & FSL_DMA_CHAN_START_EXT)
+       if (chan->feature & FSL_DMA_CHAN_START_EXT)
                mode |= FSL_DMA_MR_EMS_EN;
        else
                mode |= FSL_DMA_MR_CS;
 
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 }
 
-static void dma_halt(struct fsldma_chan *fsl_chan)
+static void dma_halt(struct fsldma_chan *chan)
 {
        u32 mode;
        int i;
 
-       mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
+       mode = DMA_IN(chan, &chan->regs->mr, 32);
        mode |= FSL_DMA_MR_CA;
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 
        mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 
        for (i = 0; i < 100; i++) {
-               if (dma_is_idle(fsl_chan))
-                       break;
+               if (dma_is_idle(chan))
+                       return;
+
                udelay(10);
        }
 
-       if (i >= 100 && !dma_is_idle(fsl_chan))
-               dev_err(fsl_chan->dev, "DMA halt timeout!\n");
+       if (!dma_is_idle(chan))
+               dev_err(chan->dev, "DMA halt timeout!\n");
 }
 
-static void set_ld_eol(struct fsldma_chan *fsl_chan,
+static void set_ld_eol(struct fsldma_chan *chan,
                        struct fsl_desc_sw *desc)
 {
        u64 snoop_bits;
 
-       snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+       snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
                ? FSL_DMA_SNEN : 0;
 
-       desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
-               DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
+       desc->hw.next_ln_addr = CPU_TO_DMA(chan,
+               DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
                        | snoop_bits, 64);
 }
 
-static void append_ld_queue(struct fsldma_chan *fsl_chan,
-               struct fsl_desc_sw *new_desc)
-{
-       struct fsl_desc_sw *queue_tail = to_fsl_desc(fsl_chan->ld_queue.prev);
-
-       if (list_empty(&fsl_chan->ld_queue))
-               return;
-
-       /* Link to the new descriptor physical address and
-        * Enable End-of-segment interrupt for
-        * the last link descriptor.
-        * (the previous node's next link descriptor)
-        *
-        * For FSL_DMA_IP_83xx, the snoop enable bit need be set.
-        */
-       queue_tail->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
-                       new_desc->async_tx.phys | FSL_DMA_EOSIE |
-                       (((fsl_chan->feature & FSL_DMA_IP_MASK)
-                               == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0), 64);
-}
-
 /**
  * fsl_chan_set_src_loop_size - Set source address hold transfer size
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  * @size     : Address loop size, 0 for disable loop
  *
  * The set source address hold transfer size. The source
@@ -231,11 +206,11 @@ static void append_ld_queue(struct fsldma_chan *fsl_chan,
  * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
  * SA + 1 ... and so on.
  */
-static void fsl_chan_set_src_loop_size(struct fsldma_chan *fsl_chan, int size)
+static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size)
 {
        u32 mode;
 
-       mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
+       mode = DMA_IN(chan, &chan->regs->mr, 32);
 
        switch (size) {
        case 0:
@@ -249,12 +224,12 @@ static void fsl_chan_set_src_loop_size(struct fsldma_chan *fsl_chan, int size)
                break;
        }
 
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 }
 
 /**
  * fsl_chan_set_dst_loop_size - Set destination address hold transfer size
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  * @size     : Address loop size, 0 for disable loop
  *
  * The set destination address hold transfer size. The destination
@@ -263,11 +238,11 @@ static void fsl_chan_set_src_loop_size(struct fsldma_chan *fsl_chan, int size)
  * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
  * TA + 1 ... and so on.
  */
-static void fsl_chan_set_dst_loop_size(struct fsldma_chan *fsl_chan, int size)
+static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size)
 {
        u32 mode;
 
-       mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
+       mode = DMA_IN(chan, &chan->regs->mr, 32);
 
        switch (size) {
        case 0:
@@ -281,12 +256,12 @@ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *fsl_chan, int size)
                break;
        }
 
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 }
 
 /**
  * fsl_chan_set_request_count - Set DMA Request Count for external control
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  * @size     : Number of bytes to transfer in a single request
  *
  * The Freescale DMA channel can be controlled by the external signal DREQ#.
@@ -296,38 +271,38 @@ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *fsl_chan, int size)
  *
  * A size of 0 disables external pause control. The maximum size is 1024.
  */
-static void fsl_chan_set_request_count(struct fsldma_chan *fsl_chan, int size)
+static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size)
 {
        u32 mode;
 
        BUG_ON(size > 1024);
 
-       mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
+       mode = DMA_IN(chan, &chan->regs->mr, 32);
        mode |= (__ilog2(size) << 24) & 0x0f000000;
 
-       DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
+       DMA_OUT(chan, &chan->regs->mr, mode, 32);
 }
 
 /**
  * fsl_chan_toggle_ext_pause - Toggle channel external pause status
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  * @enable   : 0 is disabled, 1 is enabled.
  *
  * The Freescale DMA channel can be controlled by the external signal DREQ#.
  * The DMA Request Count feature should be used in addition to this feature
  * to set the number of bytes to transfer before pausing the channel.
  */
-static void fsl_chan_toggle_ext_pause(struct fsldma_chan *fsl_chan, int enable)
+static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable)
 {
        if (enable)
-               fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
+               chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
        else
-               fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
+               chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
 }
 
 /**
  * fsl_chan_toggle_ext_start - Toggle channel external start status
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  * @enable   : 0 is disabled, 1 is enabled.
  *
  * If enable the external start, the channel can be started by an
@@ -335,141 +310,196 @@ static void fsl_chan_toggle_ext_pause(struct fsldma_chan *fsl_chan, int enable)
  * transfer immediately. The DMA channel will wait for the
  * control pin asserted.
  */
-static void fsl_chan_toggle_ext_start(struct fsldma_chan *fsl_chan, int enable)
+static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
 {
        if (enable)
-               fsl_chan->feature |= FSL_DMA_CHAN_START_EXT;
+               chan->feature |= FSL_DMA_CHAN_START_EXT;
        else
-               fsl_chan->feature &= ~FSL_DMA_CHAN_START_EXT;
+               chan->feature &= ~FSL_DMA_CHAN_START_EXT;
+}
+
+static void append_ld_queue(struct fsldma_chan *chan,
+                           struct fsl_desc_sw *desc)
+{
+       struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
+
+       if (list_empty(&chan->ld_pending))
+               goto out_splice;
+
+       /*
+        * Add the hardware descriptor to the chain of hardware descriptors
+        * that already exists in memory.
+        *
+        * This will un-set the EOL bit of the existing transaction, and the
+        * last link in this transaction will become the EOL descriptor.
+        */
+       set_desc_next(chan, &tail->hw, desc->async_tx.phys);
+
+       /*
+        * Add the software descriptor and all children to the list
+        * of pending transactions
+        */
+out_splice:
+       list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
 }
 
 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 {
-       struct fsldma_chan *fsl_chan = to_fsl_chan(tx->chan);
+       struct fsldma_chan *chan = to_fsl_chan(tx->chan);
        struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
        struct fsl_desc_sw *child;
        unsigned long flags;
        dma_cookie_t cookie;
 
-       /* cookie increment and adding to ld_queue must be atomic */
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
-       cookie = fsl_chan->common.cookie;
+       /*
+        * assign cookies to all of the software descriptors
+        * that make up this transaction
+        */
+       cookie = chan->common.cookie;
        list_for_each_entry(child, &desc->tx_list, node) {
                cookie++;
                if (cookie < 0)
                        cookie = 1;
 
-               desc->async_tx.cookie = cookie;
+               child->async_tx.cookie = cookie;
        }
 
-       fsl_chan->common.cookie = cookie;
-       append_ld_queue(fsl_chan, desc);
-       list_splice_init(&desc->tx_list, fsl_chan->ld_queue.prev);
+       chan->common.cookie = cookie;
 
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+       /* put this transaction onto the tail of the pending queue */
+       append_ld_queue(chan, desc);
+
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
 
        return cookie;
 }
 
 /**
  * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  *
  * Return - The descriptor allocated. NULL for failed.
  */
 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
-                                       struct fsldma_chan *fsl_chan)
+                                       struct fsldma_chan *chan)
 {
+       struct fsl_desc_sw *desc;
        dma_addr_t pdesc;
-       struct fsl_desc_sw *desc_sw;
-
-       desc_sw = dma_pool_alloc(fsl_chan->desc_pool, GFP_ATOMIC, &pdesc);
-       if (desc_sw) {
-               memset(desc_sw, 0, sizeof(struct fsl_desc_sw));
-               INIT_LIST_HEAD(&desc_sw->tx_list);
-               dma_async_tx_descriptor_init(&desc_sw->async_tx,
-                                               &fsl_chan->common);
-               desc_sw->async_tx.tx_submit = fsl_dma_tx_submit;
-               desc_sw->async_tx.phys = pdesc;
+
+       desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
+       if (!desc) {
+               dev_dbg(chan->dev, "out of memory for link desc\n");
+               return NULL;
        }
 
-       return desc_sw;
+       memset(desc, 0, sizeof(*desc));
+       INIT_LIST_HEAD(&desc->tx_list);
+       dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+       desc->async_tx.tx_submit = fsl_dma_tx_submit;
+       desc->async_tx.phys = pdesc;
+
+       return desc;
 }
 
 
 /**
  * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  *
  * This function will create a dma pool for descriptor allocation.
  *
  * Return - The number of descriptors allocated.
  */
-static int fsl_dma_alloc_chan_resources(struct dma_chan *chan)
+static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
 {
-       struct fsldma_chan *fsl_chan = to_fsl_chan(chan);
+       struct fsldma_chan *chan = to_fsl_chan(dchan);
 
        /* Has this channel already been allocated? */
-       if (fsl_chan->desc_pool)
+       if (chan->desc_pool)
                return 1;
 
-       /* We need the descriptor to be aligned to 32bytes
+       /*
+        * We need the descriptor to be aligned to 32bytes
         * for meeting FSL DMA specification requirement.
         */
-       fsl_chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
-                       fsl_chan->dev, sizeof(struct fsl_desc_sw),
-                       32, 0);
-       if (!fsl_chan->desc_pool) {
-               dev_err(fsl_chan->dev, "No memory for channel %d "
-                       "descriptor dma pool.\n", fsl_chan->id);
-               return 0;
+       chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
+                                         chan->dev,
+                                         sizeof(struct fsl_desc_sw),
+                                         __alignof__(struct fsl_desc_sw), 0);
+       if (!chan->desc_pool) {
+               dev_err(chan->dev, "unable to allocate channel %d "
+                                  "descriptor pool\n", chan->id);
+               return -ENOMEM;
        }
 
+       /* there is at least one descriptor free to be allocated */
        return 1;
 }
 
 /**
- * fsl_dma_free_chan_resources - Free all resources of the channel.
- * @fsl_chan : Freescale DMA channel
+ * fsldma_free_desc_list - Free all descriptors in a queue
+ * @chan: Freescae DMA channel
+ * @list: the list to free
+ *
+ * LOCKING: must hold chan->desc_lock
  */
-static void fsl_dma_free_chan_resources(struct dma_chan *chan)
+static void fsldma_free_desc_list(struct fsldma_chan *chan,
+                                 struct list_head *list)
 {
-       struct fsldma_chan *fsl_chan = to_fsl_chan(chan);
        struct fsl_desc_sw *desc, *_desc;
-       unsigned long flags;
 
-       dev_dbg(fsl_chan->dev, "Free all channel resources.\n");
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
-       list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
-#ifdef FSL_DMA_LD_DEBUG
-               dev_dbg(fsl_chan->dev,
-                               "LD %p will be released.\n", desc);
-#endif
+       list_for_each_entry_safe(desc, _desc, list, node) {
                list_del(&desc->node);
-               /* free link descriptor */
-               dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
        }
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
-       dma_pool_destroy(fsl_chan->desc_pool);
+}
+
+static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
+                                         struct list_head *list)
+{
+       struct fsl_desc_sw *desc, *_desc;
+
+       list_for_each_entry_safe_reverse(desc, _desc, list, node) {
+               list_del(&desc->node);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+       }
+}
+
+/**
+ * fsl_dma_free_chan_resources - Free all resources of the channel.
+ * @chan : Freescale DMA channel
+ */
+static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
+{
+       struct fsldma_chan *chan = to_fsl_chan(dchan);
+       unsigned long flags;
+
+       dev_dbg(chan->dev, "Free all channel resources.\n");
+       spin_lock_irqsave(&chan->desc_lock, flags);
+       fsldma_free_desc_list(chan, &chan->ld_pending);
+       fsldma_free_desc_list(chan, &chan->ld_running);
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
 
-       fsl_chan->desc_pool = NULL;
+       dma_pool_destroy(chan->desc_pool);
+       chan->desc_pool = NULL;
 }
 
 static struct dma_async_tx_descriptor *
-fsl_dma_prep_interrupt(struct dma_chan *chan, unsigned long flags)
+fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
 {
-       struct fsldma_chan *fsl_chan;
+       struct fsldma_chan *chan;
        struct fsl_desc_sw *new;
 
-       if (!chan)
+       if (!dchan)
                return NULL;
 
-       fsl_chan = to_fsl_chan(chan);
+       chan = to_fsl_chan(dchan);
 
-       new = fsl_dma_alloc_descriptor(fsl_chan);
+       new = fsl_dma_alloc_descriptor(chan);
        if (!new) {
-               dev_err(fsl_chan->dev, "No free memory for link descriptor\n");
+               dev_err(chan->dev, "No free memory for link descriptor\n");
                return NULL;
        }
 
@@ -480,51 +510,50 @@ fsl_dma_prep_interrupt(struct dma_chan *chan, unsigned long flags)
        list_add_tail(&new->node, &new->tx_list);
 
        /* Set End-of-link to the last link descriptor of new list*/
-       set_ld_eol(fsl_chan, new);
+       set_ld_eol(chan, new);
 
        return &new->async_tx;
 }
 
 static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
-       struct dma_chan *chan, dma_addr_t dma_dst, dma_addr_t dma_src,
+       struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src,
        size_t len, unsigned long flags)
 {
-       struct fsldma_chan *fsl_chan;
+       struct fsldma_chan *chan;
        struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
-       struct list_head *list;
        size_t copy;
 
-       if (!chan)
+       if (!dchan)
                return NULL;
 
        if (!len)
                return NULL;
 
-       fsl_chan = to_fsl_chan(chan);
+       chan = to_fsl_chan(dchan);
 
        do {
 
                /* Allocate the link descriptor from DMA pool */
-               new = fsl_dma_alloc_descriptor(fsl_chan);
+               new = fsl_dma_alloc_descriptor(chan);
                if (!new) {
-                       dev_err(fsl_chan->dev,
+                       dev_err(chan->dev,
                                        "No free memory for link descriptor\n");
                        goto fail;
                }
 #ifdef FSL_DMA_LD_DEBUG
-               dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new);
+               dev_dbg(chan->dev, "new link desc alloc %p\n", new);
 #endif
 
                copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
 
-               set_desc_cnt(fsl_chan, &new->hw, copy);
-               set_desc_src(fsl_chan, &new->hw, dma_src);
-               set_desc_dst(fsl_chan, &new->hw, dma_dst);
+               set_desc_cnt(chan, &new->hw, copy);
+               set_desc_src(chan, &new->hw, dma_src);
+               set_desc_dst(chan, &new->hw, dma_dst);
 
                if (!first)
                        first = new;
                else
-                       set_desc_next(fsl_chan, &prev->hw, new->async_tx.phys);
+                       set_desc_next(chan, &prev->hw, new->async_tx.phys);
 
                new->async_tx.cookie = 0;
                async_tx_ack(&new->async_tx);
@@ -542,7 +571,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
        new->async_tx.cookie = -EBUSY;
 
        /* Set End-of-link to the last link descriptor of new list*/
-       set_ld_eol(fsl_chan, new);
+       set_ld_eol(chan, new);
 
        return &first->async_tx;
 
@@ -550,12 +579,7 @@ fail:
        if (!first)
                return NULL;
 
-       list = &first->tx_list;
-       list_for_each_entry_safe_reverse(new, prev, list, node) {
-               list_del(&new->node);
-               dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys);
-       }
-
+       fsldma_free_desc_list_reverse(chan, &first->tx_list);
        return NULL;
 }
 
@@ -572,13 +596,12 @@ fail:
  * chan->private variable.
  */
 static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
-       struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
+       struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
        enum dma_data_direction direction, unsigned long flags)
 {
-       struct fsldma_chan *fsl_chan;
+       struct fsldma_chan *chan;
        struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
        struct fsl_dma_slave *slave;
-       struct list_head *tx_list;
        size_t copy;
 
        int i;
@@ -588,14 +611,14 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
        struct fsl_dma_hw_addr *hw;
        dma_addr_t dma_dst, dma_src;
 
-       if (!chan)
+       if (!dchan)
                return NULL;
 
-       if (!chan->private)
+       if (!dchan->private)
                return NULL;
 
-       fsl_chan = to_fsl_chan(chan);
-       slave = chan->private;
+       chan = to_fsl_chan(dchan);
+       slave = dchan->private;
 
        if (list_empty(&slave->addresses))
                return NULL;
@@ -644,14 +667,14 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
                        }
 
                        /* Allocate the link descriptor from DMA pool */
-                       new = fsl_dma_alloc_descriptor(fsl_chan);
+                       new = fsl_dma_alloc_descriptor(chan);
                        if (!new) {
-                               dev_err(fsl_chan->dev, "No free memory for "
+                               dev_err(chan->dev, "No free memory for "
                                                       "link descriptor\n");
                                goto fail;
                        }
 #ifdef FSL_DMA_LD_DEBUG
-                       dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new);
+                       dev_dbg(chan->dev, "new link desc alloc %p\n", new);
 #endif
 
                        /*
@@ -678,9 +701,9 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
                        }
 
                        /* Fill in the descriptor */
-                       set_desc_cnt(fsl_chan, &new->hw, copy);
-                       set_desc_src(fsl_chan, &new->hw, dma_src);
-                       set_desc_dst(fsl_chan, &new->hw, dma_dst);
+                       set_desc_cnt(chan, &new->hw, copy);
+                       set_desc_src(chan, &new->hw, dma_src);
+                       set_desc_dst(chan, &new->hw, dma_dst);
 
                        /*
                         * If this is not the first descriptor, chain the
@@ -689,7 +712,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
                        if (!first) {
                                first = new;
                        } else {
-                               set_desc_next(fsl_chan, &prev->hw,
+                               set_desc_next(chan, &prev->hw,
                                              new->async_tx.phys);
                        }
 
@@ -715,23 +738,23 @@ finished:
        new->async_tx.cookie = -EBUSY;
 
        /* Set End-of-link to the last link descriptor of new list */
-       set_ld_eol(fsl_chan, new);
+       set_ld_eol(chan, new);
 
        /* Enable extra controller features */
-       if (fsl_chan->set_src_loop_size)
-               fsl_chan->set_src_loop_size(fsl_chan, slave->src_loop_size);
+       if (chan->set_src_loop_size)
+               chan->set_src_loop_size(chan, slave->src_loop_size);
 
-       if (fsl_chan->set_dst_loop_size)
-               fsl_chan->set_dst_loop_size(fsl_chan, slave->dst_loop_size);
+       if (chan->set_dst_loop_size)
+               chan->set_dst_loop_size(chan, slave->dst_loop_size);
 
-       if (fsl_chan->toggle_ext_start)
-               fsl_chan->toggle_ext_start(fsl_chan, slave->external_start);
+       if (chan->toggle_ext_start)
+               chan->toggle_ext_start(chan, slave->external_start);
 
-       if (fsl_chan->toggle_ext_pause)
-               fsl_chan->toggle_ext_pause(fsl_chan, slave->external_pause);
+       if (chan->toggle_ext_pause)
+               chan->toggle_ext_pause(chan, slave->external_pause);
 
-       if (fsl_chan->set_request_count)
-               fsl_chan->set_request_count(fsl_chan, slave->request_count);
+       if (chan->set_request_count)
+               chan->set_request_count(chan, slave->request_count);
 
        return &first->async_tx;
 
@@ -748,215 +771,216 @@ fail:
         *
         * We're re-using variables for the loop, oh well
         */
-       tx_list = &first->tx_list;
-       list_for_each_entry_safe_reverse(new, prev, tx_list, node) {
-               list_del_init(&new->node);
-               dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys);
-       }
-
+       fsldma_free_desc_list_reverse(chan, &first->tx_list);
        return NULL;
 }
 
-static void fsl_dma_device_terminate_all(struct dma_chan *chan)
+static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
 {
-       struct fsldma_chan *fsl_chan;
-       struct fsl_desc_sw *desc, *tmp;
+       struct fsldma_chan *chan;
        unsigned long flags;
 
-       if (!chan)
+       if (!dchan)
                return;
 
-       fsl_chan = to_fsl_chan(chan);
+       chan = to_fsl_chan(dchan);
 
        /* Halt the DMA engine */
-       dma_halt(fsl_chan);
+       dma_halt(chan);
 
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
        /* Remove and free all of the descriptors in the LD queue */
-       list_for_each_entry_safe(desc, tmp, &fsl_chan->ld_queue, node) {
-               list_del(&desc->node);
-               dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
-       }
+       fsldma_free_desc_list(chan, &chan->ld_pending);
+       fsldma_free_desc_list(chan, &chan->ld_running);
 
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
  * fsl_dma_update_completed_cookie - Update the completed cookie.
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
+ *
+ * CONTEXT: hardirq
  */
-static void fsl_dma_update_completed_cookie(struct fsldma_chan *fsl_chan)
+static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
 {
-       struct fsl_desc_sw *cur_desc, *desc;
-       dma_addr_t ld_phy;
+       struct fsl_desc_sw *desc;
+       unsigned long flags;
+       dma_cookie_t cookie;
 
-       ld_phy = get_cdar(fsl_chan) & FSL_DMA_NLDA_MASK;
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
-       if (ld_phy) {
-               cur_desc = NULL;
-               list_for_each_entry(desc, &fsl_chan->ld_queue, node)
-                       if (desc->async_tx.phys == ld_phy) {
-                               cur_desc = desc;
-                               break;
-                       }
+       if (list_empty(&chan->ld_running)) {
+               dev_dbg(chan->dev, "no running descriptors\n");
+               goto out_unlock;
+       }
 
-               if (cur_desc && cur_desc->async_tx.cookie) {
-                       if (dma_is_idle(fsl_chan))
-                               fsl_chan->completed_cookie =
-                                       cur_desc->async_tx.cookie;
-                       else
-                               fsl_chan->completed_cookie =
-                                       cur_desc->async_tx.cookie - 1;
-               }
+       /* Get the last descriptor, update the cookie to that */
+       desc = to_fsl_desc(chan->ld_running.prev);
+       if (dma_is_idle(chan))
+               cookie = desc->async_tx.cookie;
+       else {
+               cookie = desc->async_tx.cookie - 1;
+               if (unlikely(cookie < DMA_MIN_COOKIE))
+                       cookie = DMA_MAX_COOKIE;
        }
+
+       chan->completed_cookie = cookie;
+
+out_unlock:
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
+}
+
+/**
+ * fsldma_desc_status - Check the status of a descriptor
+ * @chan: Freescale DMA channel
+ * @desc: DMA SW descriptor
+ *
+ * This function will return the status of the given descriptor
+ */
+static enum dma_status fsldma_desc_status(struct fsldma_chan *chan,
+                                         struct fsl_desc_sw *desc)
+{
+       return dma_async_is_complete(desc->async_tx.cookie,
+                                    chan->completed_cookie,
+                                    chan->common.cookie);
 }
 
 /**
  * fsl_chan_ld_cleanup - Clean up link descriptors
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  *
  * This function clean up the ld_queue of DMA channel.
- * If 'in_intr' is set, the function will move the link descriptor to
- * the recycle list. Otherwise, free it directly.
  */
-static void fsl_chan_ld_cleanup(struct fsldma_chan *fsl_chan)
+static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
 {
        struct fsl_desc_sw *desc, *_desc;
        unsigned long flags;
 
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
-       dev_dbg(fsl_chan->dev, "chan completed_cookie = %d\n",
-                       fsl_chan->completed_cookie);
-       list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
+       dev_dbg(chan->dev, "chan completed_cookie = %d\n", chan->completed_cookie);
+       list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
                dma_async_tx_callback callback;
                void *callback_param;
 
-               if (dma_async_is_complete(desc->async_tx.cookie,
-                           fsl_chan->completed_cookie, fsl_chan->common.cookie)
-                               == DMA_IN_PROGRESS)
+               if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
                        break;
 
-               callback = desc->async_tx.callback;
-               callback_param = desc->async_tx.callback_param;
-
-               /* Remove from ld_queue list */
+               /* Remove from the list of running transactions */
                list_del(&desc->node);
 
-               dev_dbg(fsl_chan->dev, "link descriptor %p will be recycle.\n",
-                               desc);
-               dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
-
                /* Run the link descriptor callback function */
+               callback = desc->async_tx.callback;
+               callback_param = desc->async_tx.callback_param;
                if (callback) {
-                       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
-                       dev_dbg(fsl_chan->dev, "link descriptor %p callback\n",
-                                       desc);
+                       spin_unlock_irqrestore(&chan->desc_lock, flags);
+                       dev_dbg(chan->dev, "LD %p callback\n", desc);
                        callback(callback_param);
-                       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+                       spin_lock_irqsave(&chan->desc_lock, flags);
                }
+
+               /* Run any dependencies, then free the descriptor */
+               dma_run_dependencies(&desc->async_tx);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
        }
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
- * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.
- * @fsl_chan : Freescale DMA channel
+ * fsl_chan_xfer_ld_queue - transfer any pending transactions
+ * @chan : Freescale DMA channel
+ *
+ * This will make sure that any pending transactions will be run.
+ * If the DMA controller is idle, it will be started. Otherwise,
+ * the DMA controller's interrupt handler will start any pending
+ * transactions when it becomes idle.
  */
-static void fsl_chan_xfer_ld_queue(struct fsldma_chan *fsl_chan)
+static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
 {
-       struct list_head *ld_node;
-       dma_addr_t next_dst_addr;
+       struct fsl_desc_sw *desc;
        unsigned long flags;
 
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
-       if (!dma_is_idle(fsl_chan))
+       /*
+        * If the list of pending descriptors is empty, then we
+        * don't need to do any work at all
+        */
+       if (list_empty(&chan->ld_pending)) {
+               dev_dbg(chan->dev, "no pending LDs\n");
                goto out_unlock;
+       }
 
-       dma_halt(fsl_chan);
+       /*
+        * The DMA controller is not idle, which means the interrupt
+        * handler will start any queued transactions when it runs
+        * at the end of the current transaction
+        */
+       if (!dma_is_idle(chan)) {
+               dev_dbg(chan->dev, "DMA controller still busy\n");
+               goto out_unlock;
+       }
 
-       /* If there are some link descriptors
-        * not transfered in queue. We need to start it.
+       /*
+        * TODO:
+        * make sure the dma_halt() function really un-wedges the
+        * controller as much as possible
         */
+       dma_halt(chan);
 
-       /* Find the first un-transfer desciptor */
-       for (ld_node = fsl_chan->ld_queue.next;
-               (ld_node != &fsl_chan->ld_queue)
-                       && (dma_async_is_complete(
-                               to_fsl_desc(ld_node)->async_tx.cookie,
-                               fsl_chan->completed_cookie,
-                               fsl_chan->common.cookie) == DMA_SUCCESS);
-               ld_node = ld_node->next);
-
-       if (ld_node != &fsl_chan->ld_queue) {
-               /* Get the ld start address from ld_queue */
-               next_dst_addr = to_fsl_desc(ld_node)->async_tx.phys;
-               dev_dbg(fsl_chan->dev, "xfer LDs staring from 0x%llx\n",
-                               (unsigned long long)next_dst_addr);
-               set_cdar(fsl_chan, next_dst_addr);
-               dma_start(fsl_chan);
-       } else {
-               set_cdar(fsl_chan, 0);
-               set_ndar(fsl_chan, 0);
-       }
+       /*
+        * If there are some link descriptors which have not been
+        * transferred, we need to start the controller
+        */
+
+       /*
+        * Move all elements from the queue of pending transactions
+        * onto the list of running transactions
+        */
+       desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
+       list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
+
+       /*
+        * Program the descriptor's address into the DMA controller,
+        * then start the DMA transaction
+        */
+       set_cdar(chan, desc->async_tx.phys);
+       dma_start(chan);
 
 out_unlock:
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
  * fsl_dma_memcpy_issue_pending - Issue the DMA start command
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  */
-static void fsl_dma_memcpy_issue_pending(struct dma_chan *chan)
+static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
 {
-       struct fsldma_chan *fsl_chan = to_fsl_chan(chan);
-
-#ifdef FSL_DMA_LD_DEBUG
-       struct fsl_desc_sw *ld;
-       unsigned long flags;
-
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
-       if (list_empty(&fsl_chan->ld_queue)) {
-               spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
-               return;
-       }
-
-       dev_dbg(fsl_chan->dev, "--memcpy issue--\n");
-       list_for_each_entry(ld, &fsl_chan->ld_queue, node) {
-               int i;
-               dev_dbg(fsl_chan->dev, "Ch %d, LD %08x\n",
-                               fsl_chan->id, ld->async_tx.phys);
-               for (i = 0; i < 8; i++)
-                       dev_dbg(fsl_chan->dev, "LD offset %d: %08x\n",
-                                       i, *(((u32 *)&ld->hw) + i));
-       }
-       dev_dbg(fsl_chan->dev, "----------------\n");
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
-#endif
-
-       fsl_chan_xfer_ld_queue(fsl_chan);
+       struct fsldma_chan *chan = to_fsl_chan(dchan);
+       fsl_chan_xfer_ld_queue(chan);
 }
 
 /**
  * fsl_dma_is_complete - Determine the DMA status
- * @fsl_chan : Freescale DMA channel
+ * @chan : Freescale DMA channel
  */
-static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
+static enum dma_status fsl_dma_is_complete(struct dma_chan *dchan,
                                        dma_cookie_t cookie,
                                        dma_cookie_t *done,
                                        dma_cookie_t *used)
 {
-       struct fsldma_chan *fsl_chan = to_fsl_chan(chan);
+       struct fsldma_chan *chan = to_fsl_chan(dchan);
        dma_cookie_t last_used;
        dma_cookie_t last_complete;
 
-       fsl_chan_ld_cleanup(fsl_chan);
+       fsl_chan_ld_cleanup(chan);
 
-       last_used = chan->cookie;
-       last_complete = fsl_chan->completed_cookie;
+       last_used = dchan->cookie;
+       last_complete = chan->completed_cookie;
 
        if (done)
                *done = last_complete;
@@ -967,32 +991,37 @@ static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
        return dma_async_is_complete(cookie, last_complete, last_used);
 }
 
+/*----------------------------------------------------------------------------*/
+/* Interrupt Handling                                                         */
+/*----------------------------------------------------------------------------*/
+
 static irqreturn_t fsldma_chan_irq(int irq, void *data)
 {
-       struct fsldma_chan *fsl_chan = data;
-       u32 stat;
+       struct fsldma_chan *chan = data;
        int update_cookie = 0;
        int xfer_ld_q = 0;
+       u32 stat;
 
-       stat = get_sr(fsl_chan);
-       dev_dbg(fsl_chan->dev, "event: channel %d, stat = 0x%x\n",
-                                               fsl_chan->id, stat);
-       set_sr(fsl_chan, stat);         /* Clear the event register */
+       /* save and clear the status register */
+       stat = get_sr(chan);
+       set_sr(chan, stat);
+       dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat);
 
        stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
        if (!stat)
                return IRQ_NONE;
 
        if (stat & FSL_DMA_SR_TE)
-               dev_err(fsl_chan->dev, "Transfer Error!\n");
+               dev_err(chan->dev, "Transfer Error!\n");
 
-       /* Programming Error
+       /*
+        * Programming Error
         * The DMA_INTERRUPT async_tx is a NULL transfer, which will
         * triger a PE interrupt.
         */
        if (stat & FSL_DMA_SR_PE) {
-               dev_dbg(fsl_chan->dev, "event: Programming Error INT\n");
-               if (get_bcr(fsl_chan) == 0) {
+               dev_dbg(chan->dev, "irq: Programming Error INT\n");
+               if (get_bcr(chan) == 0) {
                        /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
                         * Now, update the completed cookie, and continue the
                         * next uncompleted transfer.
@@ -1003,69 +1032,163 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
                stat &= ~FSL_DMA_SR_PE;
        }
 
-       /* If the link descriptor segment transfer finishes,
+       /*
+        * If the link descriptor segment transfer finishes,
         * we will recycle the used descriptor.
         */
        if (stat & FSL_DMA_SR_EOSI) {
-               dev_dbg(fsl_chan->dev, "event: End-of-segments INT\n");
-               dev_dbg(fsl_chan->dev, "event: clndar 0x%llx, nlndar 0x%llx\n",
-                       (unsigned long long)get_cdar(fsl_chan),
-                       (unsigned long long)get_ndar(fsl_chan));
+               dev_dbg(chan->dev, "irq: End-of-segments INT\n");
+               dev_dbg(chan->dev, "irq: clndar 0x%llx, nlndar 0x%llx\n",
+                       (unsigned long long)get_cdar(chan),
+                       (unsigned long long)get_ndar(chan));
                stat &= ~FSL_DMA_SR_EOSI;
                update_cookie = 1;
        }
 
-       /* For MPC8349, EOCDI event need to update cookie
+       /*
+        * For MPC8349, EOCDI event need to update cookie
         * and start the next transfer if it exist.
         */
        if (stat & FSL_DMA_SR_EOCDI) {
-               dev_dbg(fsl_chan->dev, "event: End-of-Chain link INT\n");
+               dev_dbg(chan->dev, "irq: End-of-Chain link INT\n");
                stat &= ~FSL_DMA_SR_EOCDI;
                update_cookie = 1;
                xfer_ld_q = 1;
        }
 
-       /* If it current transfer is the end-of-transfer,
+       /*
+        * If it current transfer is the end-of-transfer,
         * we should clear the Channel Start bit for
         * prepare next transfer.
         */
        if (stat & FSL_DMA_SR_EOLNI) {
-               dev_dbg(fsl_chan->dev, "event: End-of-link INT\n");
+               dev_dbg(chan->dev, "irq: End-of-link INT\n");
                stat &= ~FSL_DMA_SR_EOLNI;
                xfer_ld_q = 1;
        }
 
        if (update_cookie)
-               fsl_dma_update_completed_cookie(fsl_chan);
+               fsl_dma_update_completed_cookie(chan);
        if (xfer_ld_q)
-               fsl_chan_xfer_ld_queue(fsl_chan);
+               fsl_chan_xfer_ld_queue(chan);
        if (stat)
-               dev_dbg(fsl_chan->dev, "event: unhandled sr 0x%02x\n",
-                                       stat);
+               dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat);
 
-       dev_dbg(fsl_chan->dev, "event: Exit\n");
-       tasklet_schedule(&fsl_chan->tasklet);
+       dev_dbg(chan->dev, "irq: Exit\n");
+       tasklet_schedule(&chan->tasklet);
        return IRQ_HANDLED;
 }
 
-static irqreturn_t fsldma_irq(int irq, void *data)
+static void dma_do_tasklet(unsigned long data)
+{
+       struct fsldma_chan *chan = (struct fsldma_chan *)data;
+       fsl_chan_ld_cleanup(chan);
+}
+
+static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
 {
        struct fsldma_device *fdev = data;
-       int ch_nr;
-       u32 gsr;
+       struct fsldma_chan *chan;
+       unsigned int handled = 0;
+       u32 gsr, mask;
+       int i;
 
        gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
-                       : in_le32(fdev->regs);
-       ch_nr = (32 - ffs(gsr)) / 8;
+                                                  : in_le32(fdev->regs);
+       mask = 0xff000000;
+       dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr);
 
-       return fdev->chan[ch_nr] ? fsldma_chan_irq(irq,
-                       fdev->chan[ch_nr]) : IRQ_NONE;
+       for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+               chan = fdev->chan[i];
+               if (!chan)
+                       continue;
+
+               if (gsr & mask) {
+                       dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id);
+                       fsldma_chan_irq(irq, chan);
+                       handled++;
+               }
+
+               gsr &= ~mask;
+               mask >>= 8;
+       }
+
+       return IRQ_RETVAL(handled);
 }
 
-static void dma_do_tasklet(unsigned long data)
+static void fsldma_free_irqs(struct fsldma_device *fdev)
 {
-       struct fsldma_chan *fsl_chan = (struct fsldma_chan *)data;
-       fsl_chan_ld_cleanup(fsl_chan);
+       struct fsldma_chan *chan;
+       int i;
+
+       if (fdev->irq != NO_IRQ) {
+               dev_dbg(fdev->dev, "free per-controller IRQ\n");
+               free_irq(fdev->irq, fdev);
+               return;
+       }
+
+       for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+               chan = fdev->chan[i];
+               if (chan && chan->irq != NO_IRQ) {
+                       dev_dbg(fdev->dev, "free channel %d IRQ\n", chan->id);
+                       free_irq(chan->irq, chan);
+               }
+       }
+}
+
+static int fsldma_request_irqs(struct fsldma_device *fdev)
+{
+       struct fsldma_chan *chan;
+       int ret;
+       int i;
+
+       /* if we have a per-controller IRQ, use that */
+       if (fdev->irq != NO_IRQ) {
+               dev_dbg(fdev->dev, "request per-controller IRQ\n");
+               ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED,
+                                 "fsldma-controller", fdev);
+               return ret;
+       }
+
+       /* no per-controller IRQ, use the per-channel IRQs */
+       for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
+               chan = fdev->chan[i];
+               if (!chan)
+                       continue;
+
+               if (chan->irq == NO_IRQ) {
+                       dev_err(fdev->dev, "no interrupts property defined for "
+                                          "DMA channel %d. Please fix your "
+                                          "device tree\n", chan->id);
+                       ret = -ENODEV;
+                       goto out_unwind;
+               }
+
+               dev_dbg(fdev->dev, "request channel %d IRQ\n", chan->id);
+               ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
+                                 "fsldma-chan", chan);
+               if (ret) {
+                       dev_err(fdev->dev, "unable to request IRQ for DMA "
+                                          "channel %d\n", chan->id);
+                       goto out_unwind;
+               }
+       }
+
+       return 0;
+
+out_unwind:
+       for (/* none */; i >= 0; i--) {
+               chan = fdev->chan[i];
+               if (!chan)
+                       continue;
+
+               if (chan->irq == NO_IRQ)
+                       continue;
+
+               free_irq(chan->irq, chan);
+       }
+
+       return ret;
 }
 
 /*----------------------------------------------------------------------------*/
@@ -1075,24 +1198,24 @@ static void dma_do_tasklet(unsigned long data)
 static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
        struct device_node *node, u32 feature, const char *compatible)
 {
-       struct fsldma_chan *fchan;
+       struct fsldma_chan *chan;
        struct resource res;
        int err;
 
        /* alloc channel */
-       fchan = kzalloc(sizeof(*fchan), GFP_KERNEL);
-       if (!fchan) {
+       chan = kzalloc(sizeof(*chan), GFP_KERNEL);
+       if (!chan) {
                dev_err(fdev->dev, "no free memory for DMA channels!\n");
                err = -ENOMEM;
                goto out_return;
        }
 
        /* ioremap registers for use */
-       fchan->regs = of_iomap(node, 0);
-       if (!fchan->regs) {
+       chan->regs = of_iomap(node, 0);
+       if (!chan->regs) {
                dev_err(fdev->dev, "unable to ioremap registers\n");
                err = -ENOMEM;
-               goto out_free_fchan;
+               goto out_free_chan;
        }
 
        err = of_address_to_resource(node, 0, &res);
@@ -1101,89 +1224,75 @@ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
                goto out_iounmap_regs;
        }
 
-       fchan->feature = feature;
+       chan->feature = feature;
        if (!fdev->feature)
-               fdev->feature = fchan->feature;
+               fdev->feature = chan->feature;
 
        /*
         * If the DMA device's feature is different than the feature
         * of its channels, report the bug
         */
-       WARN_ON(fdev->feature != fchan->feature);
+       WARN_ON(fdev->feature != chan->feature);
 
-       fchan->dev = fdev->dev;
-       fchan->id = ((res.start - 0x100) & 0xfff) >> 7;
-       if (fchan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
+       chan->dev = fdev->dev;
+       chan->id = ((res.start - 0x100) & 0xfff) >> 7;
+       if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
                dev_err(fdev->dev, "too many channels for device\n");
                err = -EINVAL;
                goto out_iounmap_regs;
        }
 
-       fdev->chan[fchan->id] = fchan;
-       tasklet_init(&fchan->tasklet, dma_do_tasklet, (unsigned long)fchan);
+       fdev->chan[chan->id] = chan;
+       tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
 
        /* Initialize the channel */
-       dma_init(fchan);
+       dma_init(chan);
 
        /* Clear cdar registers */
-       set_cdar(fchan, 0);
+       set_cdar(chan, 0);
 
-       switch (fchan->feature & FSL_DMA_IP_MASK) {
+       switch (chan->feature & FSL_DMA_IP_MASK) {
        case FSL_DMA_IP_85XX:
-               fchan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
+               chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
        case FSL_DMA_IP_83XX:
-               fchan->toggle_ext_start = fsl_chan_toggle_ext_start;
-               fchan->set_src_loop_size = fsl_chan_set_src_loop_size;
-               fchan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
-               fchan->set_request_count = fsl_chan_set_request_count;
+               chan->toggle_ext_start = fsl_chan_toggle_ext_start;
+               chan->set_src_loop_size = fsl_chan_set_src_loop_size;
+               chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
+               chan->set_request_count = fsl_chan_set_request_count;
        }
 
-       spin_lock_init(&fchan->desc_lock);
-       INIT_LIST_HEAD(&fchan->ld_queue);
+       spin_lock_init(&chan->desc_lock);
+       INIT_LIST_HEAD(&chan->ld_pending);
+       INIT_LIST_HEAD(&chan->ld_running);
 
-       fchan->common.device = &fdev->common;
+       chan->common.device = &fdev->common;
+
+       /* find the IRQ line, if it exists in the device tree */
+       chan->irq = irq_of_parse_and_map(node, 0);
 
        /* Add the channel to DMA device channel list */
-       list_add_tail(&fchan->common.device_node, &fdev->common.channels);
+       list_add_tail(&chan->common.device_node, &fdev->common.channels);
        fdev->common.chancnt++;
 
-       fchan->irq = irq_of_parse_and_map(node, 0);
-       if (fchan->irq != NO_IRQ) {
-               err = request_irq(fchan->irq, &fsldma_chan_irq,
-                                 IRQF_SHARED, "fsldma-channel", fchan);
-               if (err) {
-                       dev_err(fdev->dev, "unable to request IRQ "
-                                          "for channel %d\n", fchan->id);
-                       goto out_list_del;
-               }
-       }
-
-       dev_info(fdev->dev, "#%d (%s), irq %d\n", fchan->id, compatible,
-                fchan->irq != NO_IRQ ? fchan->irq : fdev->irq);
+       dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible,
+                chan->irq != NO_IRQ ? chan->irq : fdev->irq);
 
        return 0;
 
-out_list_del:
-       irq_dispose_mapping(fchan->irq);
-       list_del_init(&fchan->common.device_node);
 out_iounmap_regs:
-       iounmap(fchan->regs);
-out_free_fchan:
-       kfree(fchan);
+       iounmap(chan->regs);
+out_free_chan:
+       kfree(chan);
 out_return:
        return err;
 }
 
-static void fsl_dma_chan_remove(struct fsldma_chan *fchan)
+static void fsl_dma_chan_remove(struct fsldma_chan *chan)
 {
-       if (fchan->irq != NO_IRQ) {
-               free_irq(fchan->irq, fchan);
-               irq_dispose_mapping(fchan->irq);
-       }
-
-       list_del(&fchan->common.device_node);
-       iounmap(fchan->regs);
-       kfree(fchan);
+       irq_dispose_mapping(chan->irq);
+       list_del(&chan->common.device_node);
+       iounmap(chan->regs);
+       kfree(chan);
 }
 
 static int __devinit fsldma_of_probe(struct of_device *op,
@@ -1211,6 +1320,9 @@ static int __devinit fsldma_of_probe(struct of_device *op,
                goto out_free_fdev;
        }
 
+       /* map the channel IRQ if it exists, but don't hookup the handler yet */
+       fdev->irq = irq_of_parse_and_map(op->node, 0);
+
        dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
        dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
        dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
@@ -1224,16 +1336,6 @@ static int __devinit fsldma_of_probe(struct of_device *op,
        fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
        fdev->common.dev = &op->dev;
 
-       fdev->irq = irq_of_parse_and_map(op->node, 0);
-       if (fdev->irq != NO_IRQ) {
-               err = request_irq(fdev->irq, &fsldma_irq, IRQF_SHARED,
-                                 "fsldma-device", fdev);
-               if (err) {
-                       dev_err(&op->dev, "unable to request IRQ\n");
-                       goto out_iounmap_regs;
-               }
-       }
-
        dev_set_drvdata(&op->dev, fdev);
 
        /*
@@ -1255,12 +1357,24 @@ static int __devinit fsldma_of_probe(struct of_device *op,
                }
        }
 
+       /*
+        * Hookup the IRQ handler(s)
+        *
+        * If we have a per-controller interrupt, we prefer that to the
+        * per-channel interrupts to reduce the number of shared interrupt
+        * handlers on the same IRQ line
+        */
+       err = fsldma_request_irqs(fdev);
+       if (err) {
+               dev_err(fdev->dev, "unable to request IRQs\n");
+               goto out_free_fdev;
+       }
+
        dma_async_device_register(&fdev->common);
        return 0;
 
-out_iounmap_regs:
-       iounmap(fdev->regs);
 out_free_fdev:
+       irq_dispose_mapping(fdev->irq);
        kfree(fdev);
 out_return:
        return err;
@@ -1274,14 +1388,13 @@ static int fsldma_of_remove(struct of_device *op)
        fdev = dev_get_drvdata(&op->dev);
        dma_async_device_unregister(&fdev->common);
 
+       fsldma_free_irqs(fdev);
+
        for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
                if (fdev->chan[i])
                        fsl_dma_chan_remove(fdev->chan[i]);
        }
 
-       if (fdev->irq != NO_IRQ)
-               free_irq(fdev->irq, fdev);
-
        iounmap(fdev->regs);
        dev_set_drvdata(&op->dev, NULL);
        kfree(fdev);
@@ -1289,7 +1402,7 @@ static int fsldma_of_remove(struct of_device *op)
        return 0;
 }
 
-static struct of_device_id fsldma_of_ids[] = {
+static const struct of_device_id fsldma_of_ids[] = {
        { .compatible = "fsl,eloplus-dma", },
        { .compatible = "fsl,elo-dma", },
        {}