staging: comedi: pcl812: factor out dma setup to helper functions

To assist in cleaning up the the rest of the driver, factor the initial
dma setup and the next dma buffer setup into helper functions.

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/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 284c094..c7916e4 100644 (file)
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -550,6 +550,96 @@ static void pcl812_start_pacer(struct comedi_device *dev, bool load_timers)
        }
 }
 
+static void pcl812_ai_setup_dma(struct comedi_device *dev,
+                               struct comedi_subdevice *s)
+{
+       struct pcl812_private *devpriv = dev->private;
+       struct comedi_cmd *cmd = &s->async->cmd;
+       unsigned int dma_flags;
+       unsigned int bytes;
+
+       /*  we use EOS, so adapt DMA buffer to one scan */
+       if (devpriv->ai_eos) {
+               devpriv->dmabytestomove[0] =
+                       cmd->chanlist_len * sizeof(short);
+               devpriv->dmabytestomove[1] =
+                       cmd->chanlist_len * sizeof(short);
+               devpriv->dma_runs_to_end = 1;
+       } else {
+               devpriv->dmabytestomove[0] = devpriv->hwdmasize;
+               devpriv->dmabytestomove[1] = devpriv->hwdmasize;
+               if (devpriv->ai_data_len < devpriv->hwdmasize) {
+                       devpriv->dmabytestomove[0] =
+                               devpriv->ai_data_len;
+                       devpriv->dmabytestomove[1] =
+                               devpriv->ai_data_len;
+               }
+               if (cmd->stop_src == TRIG_NONE) {
+                       devpriv->dma_runs_to_end = 1;
+               } else {
+                       /*  how many samples we must transfer? */
+                       bytes = cmd->chanlist_len *
+                               cmd->stop_arg * sizeof(short);
+
+                       /*  how many DMA pages we must fill */
+                       devpriv->dma_runs_to_end =
+                               bytes / devpriv->dmabytestomove[0];
+
+                       /* on last dma transfer must be moved */
+                       devpriv->last_dma_run =
+                               bytes % devpriv->dmabytestomove[0];
+                       if (devpriv->dma_runs_to_end == 0)
+                               devpriv->dmabytestomove[0] =
+                                       devpriv->last_dma_run;
+                       devpriv->dma_runs_to_end--;
+               }
+       }
+       if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) {
+               devpriv->dmabytestomove[0] = devpriv->hwdmasize;
+               devpriv->ai_eos = 0;
+       }
+       if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) {
+               devpriv->dmabytestomove[1] = devpriv->hwdmasize;
+               devpriv->ai_eos = 0;
+       }
+       devpriv->next_dma_buf = 0;
+       set_dma_mode(devpriv->dma, DMA_MODE_READ);
+       dma_flags = claim_dma_lock();
+       clear_dma_ff(devpriv->dma);
+       set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);
+       set_dma_count(devpriv->dma, devpriv->dmabytestomove[0]);
+       release_dma_lock(dma_flags);
+       enable_dma(devpriv->dma);
+}
+
+static void pcl812_ai_setup_next_dma(struct comedi_device *dev,
+                                    struct comedi_subdevice *s)
+{
+       struct pcl812_private *devpriv = dev->private;
+       unsigned long dma_flags;
+
+       devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
+       disable_dma(devpriv->dma);
+       set_dma_mode(devpriv->dma, DMA_MODE_READ);
+       dma_flags = claim_dma_lock();
+       set_dma_addr(devpriv->dma, devpriv->hwdmaptr[devpriv->next_dma_buf]);
+       if (devpriv->ai_eos) {
+               set_dma_count(devpriv->dma,
+                             devpriv->dmabytestomove[devpriv->next_dma_buf]);
+       } else {
+               if (devpriv->dma_runs_to_end) {
+                       set_dma_count(devpriv->dma,
+                                     devpriv->dmabytestomove[devpriv->
+                                                             next_dma_buf]);
+               } else {
+                       set_dma_count(devpriv->dma, devpriv->last_dma_run);
+               }
+               devpriv->dma_runs_to_end--;
+       }
+       release_dma_lock(dma_flags);
+       enable_dma(devpriv->dma);
+}
+
 static unsigned int pcl812_ai_get_sample(struct comedi_device *dev,
                                         struct comedi_subdevice *s)
 {
@@ -748,7 +838,7 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 {
        struct pcl812_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;
-       unsigned int i, dma_flags, bytes;
+       unsigned int i;
 
        pcl812_start_pacer(dev, false);
 
@@ -780,60 +870,8 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
                        devpriv->ai_dma = 0;
        }
 
-       if (devpriv->ai_dma) {
-               /*  we use EOS, so adapt DMA buffer to one scan */
-               if (devpriv->ai_eos) {
-                       devpriv->dmabytestomove[0] =
-                           cmd->chanlist_len * sizeof(short);
-                       devpriv->dmabytestomove[1] =
-                           cmd->chanlist_len * sizeof(short);
-                       devpriv->dma_runs_to_end = 1;
-               } else {
-                       devpriv->dmabytestomove[0] = devpriv->hwdmasize;
-                       devpriv->dmabytestomove[1] = devpriv->hwdmasize;
-                       if (devpriv->ai_data_len < devpriv->hwdmasize) {
-                               devpriv->dmabytestomove[0] =
-                                   devpriv->ai_data_len;
-                               devpriv->dmabytestomove[1] =
-                                   devpriv->ai_data_len;
-                       }
-                       if (cmd->stop_src == TRIG_NONE) {
-                               devpriv->dma_runs_to_end = 1;
-                       } else {
-                               /*  how many samples we must transfer? */
-                               bytes = cmd->chanlist_len *
-                                       cmd->stop_arg * sizeof(short);
-
-                               /*  how many DMA pages we must fill */
-                               devpriv->dma_runs_to_end =
-                                       bytes / devpriv->dmabytestomove[0];
-
-                               /* on last dma transfer must be moved */
-                               devpriv->last_dma_run =
-                                       bytes % devpriv->dmabytestomove[0];
-                               if (devpriv->dma_runs_to_end == 0)
-                                       devpriv->dmabytestomove[0] =
-                                           devpriv->last_dma_run;
-                               devpriv->dma_runs_to_end--;
-                       }
-               }
-               if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) {
-                       devpriv->dmabytestomove[0] = devpriv->hwdmasize;
-                       devpriv->ai_eos = 0;
-               }
-               if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) {
-                       devpriv->dmabytestomove[1] = devpriv->hwdmasize;
-                       devpriv->ai_eos = 0;
-               }
-               devpriv->next_dma_buf = 0;
-               set_dma_mode(devpriv->dma, DMA_MODE_READ);
-               dma_flags = claim_dma_lock();
-               clear_dma_ff(devpriv->dma);
-               set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);
-               set_dma_count(devpriv->dma, devpriv->dmabytestomove[0]);
-               release_dma_lock(dma_flags);
-               enable_dma(devpriv->dma);
-       }
+       if (devpriv->ai_dma)
+               pcl812_ai_setup_dma(dev, s);
 
        switch (cmd->convert_src) {
        case TRIG_TIMER:
@@ -950,7 +988,6 @@ static irqreturn_t interrupt_pcl812_ai_dma(int irq, void *d)
        struct comedi_device *dev = d;
        struct pcl812_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
-       unsigned long dma_flags;
        int len, bufptr;
        unsigned short *ptr;
 
@@ -958,26 +995,7 @@ static irqreturn_t interrupt_pcl812_ai_dma(int irq, void *d)
        len = (devpriv->dmabytestomove[devpriv->next_dma_buf] >> 1) -
            devpriv->ai_poll_ptr;
 
-       devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
-       disable_dma(devpriv->dma);
-       set_dma_mode(devpriv->dma, DMA_MODE_READ);
-       dma_flags = claim_dma_lock();
-       set_dma_addr(devpriv->dma, devpriv->hwdmaptr[devpriv->next_dma_buf]);
-       if (devpriv->ai_eos) {
-               set_dma_count(devpriv->dma,
-                             devpriv->dmabytestomove[devpriv->next_dma_buf]);
-       } else {
-               if (devpriv->dma_runs_to_end) {
-                       set_dma_count(devpriv->dma,
-                                     devpriv->dmabytestomove[devpriv->
-                                                             next_dma_buf]);
-               } else {
-                       set_dma_count(devpriv->dma, devpriv->last_dma_run);
-               }
-               devpriv->dma_runs_to_end--;
-       }
-       release_dma_lock(dma_flags);
-       enable_dma(devpriv->dma);
+       pcl812_ai_setup_next_dma(dev, s);
 
        outb(0, dev->iobase + PCL812_CLRINT);   /* clear INT request */