Merge tag 'for-linus-3.4' of git://git.infradead.org/mtd-2.6

[linux-2.6-block.git] / drivers / dma / mxs-dma.c

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index 65334c49b71e92bb3c73c01306a98c86eb90b732..c81ef7e10e08283ce8eaf4fadf6166b5d3ddc19c 100644 (file)
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -22,10 +22,10 @@
 #include <linux/platform_device.h>
 #include <linux/dmaengine.h>
 #include <linux/delay.h>
+#include <linux/fsl/mxs-dma.h>
 
 #include <asm/irq.h>
 #include <mach/mxs.h>
-#include <mach/dma.h>
 #include <mach/common.h>
 
 #include "dmaengine.h"
@@ -337,10 +337,32 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)
        clk_disable_unprepare(mxs_dma->clk);
 }
 
+/*
+ * How to use the flags for ->device_prep_slave_sg() :
+ *    [1] If there is only one DMA command in the DMA chain, the code should be:
+ *            ......
+ *            ->device_prep_slave_sg(DMA_CTRL_ACK);
+ *            ......
+ *    [2] If there are two DMA commands in the DMA chain, the code should be
+ *            ......
+ *            ->device_prep_slave_sg(0);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ *            ......
+ *    [3] If there are more than two DMA commands in the DMA chain, the code
+ *        should be:
+ *            ......
+ *            ->device_prep_slave_sg(0);                                // First
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // Last
+ *            ......
+ */
 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
                struct dma_chan *chan, struct scatterlist *sgl,
                unsigned int sg_len, enum dma_transfer_direction direction,
-               unsigned long append, void *context)
+               unsigned long flags, void *context)
 {
        struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
        struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
@@ -348,6 +370,7 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
        struct scatterlist *sg;
        int i, j;
        u32 *pio;
+       bool append = flags & DMA_PREP_INTERRUPT;
        int idx = append ? mxs_chan->desc_count : 0;
 
        if (mxs_chan->status == DMA_IN_PROGRESS && !append)
@@ -374,7 +397,6 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
                ccw->bits |= CCW_CHAIN;
                ccw->bits &= ~CCW_IRQ;
                ccw->bits &= ~CCW_DEC_SEM;
-               ccw->bits &= ~CCW_WAIT4END;
        } else {
                idx = 0;
        }
@@ -389,7 +411,8 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
                ccw->bits = 0;
                ccw->bits |= CCW_IRQ;
                ccw->bits |= CCW_DEC_SEM;
-               ccw->bits |= CCW_WAIT4END;
+               if (flags & DMA_CTRL_ACK)
+                       ccw->bits |= CCW_WAIT4END;
                ccw->bits |= CCW_HALT_ON_TERM;
                ccw->bits |= CCW_TERM_FLUSH;
                ccw->bits |= BF_CCW(sg_len, PIO_NUM);
@@ -420,7 +443,8 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
                                ccw->bits &= ~CCW_CHAIN;
                                ccw->bits |= CCW_IRQ;
                                ccw->bits |= CCW_DEC_SEM;
-                               ccw->bits |= CCW_WAIT4END;
+                               if (flags & DMA_CTRL_ACK)
+                                       ccw->bits |= CCW_WAIT4END;
                        }
                }
        }