staging: comedi: adl_pci9118: introduce pci9118_amcc_setup_dma()

Introduce a helper function to program the AMCC master write address and
transfer count registers to setup a DMA transaction.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index 0526afe02c8c8b3dd7ac1104e22c07b129f62ab4..c90afdfd76cabe1b8b191a0289903d5859306f22 100644 (file)
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -294,6 +294,16 @@ struct pci9118_private {
        unsigned int ai_ns_min;
 };
 
+static void pci9118_amcc_setup_dma(struct comedi_device *dev, unsigned int buf)
+{
+       struct pci9118_private *devpriv = dev->private;
+
+       /* set the master write address and transfer count */
+       outl(devpriv->dmabuf_hw[buf], devpriv->iobase_a + AMCC_OP_REG_MWAR);
+       outl(devpriv->dmabuf_use_size[buf],
+            devpriv->iobase_a + AMCC_OP_REG_MWTC);
+}
+
 static void pci9118_amcc_dma_ena(struct comedi_device *dev, bool enable)
 {
        struct pci9118_private *devpriv = dev->private;
@@ -880,10 +890,7 @@ static void interrupt_pci9118_ai_dma(struct comedi_device *dev,
                                         * double buffering
                                         */
                next_dma_buf = 1 - devpriv->dma_actbuf;
-               outl(devpriv->dmabuf_hw[next_dma_buf],
-                    devpriv->iobase_a + AMCC_OP_REG_MWAR);
-               outl(devpriv->dmabuf_use_size[next_dma_buf],
-                    devpriv->iobase_a + AMCC_OP_REG_MWTC);
+               pci9118_amcc_setup_dma(dev, next_dma_buf);
                devpriv->dmabuf_used_size[next_dma_buf] =
                    devpriv->dmabuf_use_size[next_dma_buf];
                if (devpriv->ai_do == 4)
@@ -906,13 +913,12 @@ static void interrupt_pci9118_ai_dma(struct comedi_device *dev,
                        s->async->events |= COMEDI_CB_EOA;
        }
 
-       if (devpriv->dma_doublebuf) {   /* switch dma buffers */
+       if (devpriv->dma_doublebuf) {
+               /* switch dma buffers */
                devpriv->dma_actbuf = 1 - devpriv->dma_actbuf;
-       } else {        /* restart DMA if is not used double buffering */
-               outl(devpriv->dmabuf_hw[0],
-                    devpriv->iobase_a + AMCC_OP_REG_MWAR);
-               outl(devpriv->dmabuf_use_size[0],
-                    devpriv->iobase_a + AMCC_OP_REG_MWTC);
+       } else {
+               /* restart DMA if is not used double buffering */
+               pci9118_amcc_setup_dma(dev, 0);
                if (devpriv->ai_do == 4)
                        interrupt_pci9118_ai_mode4_switch(dev);
        }
@@ -1288,8 +1294,7 @@ static int Compute_and_setup_dma(struct comedi_device *dev,
 #endif
 
        pci9118_amcc_dma_ena(dev, false);
-       outl(devpriv->dmabuf_hw[0], devpriv->iobase_a + AMCC_OP_REG_MWAR);
-       outl(devpriv->dmabuf_use_size[0], devpriv->iobase_a + AMCC_OP_REG_MWTC);
+       pci9118_amcc_setup_dma(dev, 0);
        /* init DMA transfer */
        outl(0x00000000 | AINT_WRITE_COMPL,
             devpriv->iobase_a + AMCC_OP_REG_INTCSR);