staging: comedi: pcl816: cleanup setup_channel_list()

Move this function to remove the need for the forward declaration. Rename it
so it has namespace associated with the driver. Remove the unnecessary
comedi_subdevice parameter from the function.

The hardware has per-channel programmable gain. This function first sets the
range for each channel then sets the mux register to automatically scan the
channels.

Remove the need for the 'ai_act_chanlist' member in the private data. It is
only used to set the first/last channel to scan.

Introduce a couple helper functions to set the range for a channel and to set
the first/last channels to scan.

Tidy up the range and mux register defines.

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/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index 6ad279362d602d93ff7cf85f16a9cdaf1200e1fe..786680f32686f5d432061405757e8ff2a905991c 100644 (file)
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -49,6 +49,9 @@ Configuration Options:
 #define PCL816_TIMER_BASE                      0x04
 #define PCL816_AI_LSB_REG                      0x08
 #define PCL816_AI_MSB_REG                      0x09
+#define PCL816_RANGE_REG                       0x09
+#define PCL816_MUX_REG                         0x0b
+#define PCL816_MUX_SCAN(_first, _last)         (((_last) << 4) | (_first))
 #define PCL816_STATUS_REG                      0x0d
 #define PCL816_STATUS_NEXT_CHAN_MASK           (0xf << 0)
 #define PCL816_STATUS_INTSRC_MASK              (3 << 4)
@@ -59,12 +62,8 @@ Configuration Options:
 #define PCL816_STATUS_INTACT                   (1 << 6)
 #define PCL816_STATUS_DRDY                     (1 << 7)
 
-/* R: A/D high byte W: A/D range control */
-#define PCL816_RANGE 9
 /* W: clear INT request */
 #define PCL816_CLRINT 10
-/* R: next mux scan channel W: mux scan channel & range control pointer */
-#define PCL816_MUX 11
 /* R/W: operation control register */
 #define PCL816_CONTROL 12
 
@@ -115,7 +114,6 @@ struct pcl816_private {
        long dma_runs_to_end;   /*  how many we must permorm DMA transfer to end of record */
        unsigned long last_dma_run;     /*  how many bytes we must transfer on last DMA page */
        int ai_act_scan;        /*  how many scans we finished */
-       unsigned int ai_act_chanlist[16];       /*  MUX setting for actual AI operations */
        unsigned int ai_poll_ptr;       /*  how many sampes transfer poll */
        unsigned int divisor1;
        unsigned int divisor2;
@@ -126,9 +124,6 @@ struct pcl816_private {
 static int check_channel_list(struct comedi_device *dev,
                              struct comedi_subdevice *s,
                              unsigned int *chanlist, unsigned int chanlen);
-static void setup_channel_list(struct comedi_device *dev,
-                              struct comedi_subdevice *s,
-                              unsigned int *chanlist, unsigned int seglen);
 
 static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters)
 {
@@ -211,6 +206,44 @@ static void pcl816_ai_setup_next_dma(struct comedi_device *dev,
        devpriv->dma_runs_to_end--;
 }
 
+static void pcl816_ai_set_chan_range(struct comedi_device *dev,
+                                    unsigned int chan,
+                                    unsigned int range)
+{
+       outb(chan, dev->iobase + PCL816_MUX_REG);
+       outb(range, dev->iobase + PCL816_RANGE_REG);
+}
+
+static void pcl816_ai_set_chan_scan(struct comedi_device *dev,
+                                   unsigned int first_chan,
+                                   unsigned int last_chan)
+{
+       outb(PCL816_MUX_SCAN(first_chan, last_chan),
+            dev->iobase + PCL816_MUX_REG);
+}
+
+static void pcl816_ai_setup_chanlist(struct comedi_device *dev,
+                                    unsigned int *chanlist,
+                                    unsigned int seglen)
+{
+       unsigned int first_chan = CR_CHAN(chanlist[0]);
+       unsigned int last_chan;
+       unsigned int range;
+       unsigned int i;
+
+       /* store range list to card */
+       for (i = 0; i < seglen; i++) {
+               last_chan = CR_CHAN(chanlist[i]);
+               range = CR_RANGE(chanlist[i]);
+
+               pcl816_ai_set_chan_range(dev, last_chan, range);
+       }
+
+       udelay(1);
+
+       pcl816_ai_set_chan_scan(dev, first_chan, last_chan);
+}
+
 static void pcl816_ai_clear_eoc(struct comedi_device *dev)
 {
        /* writing any value clears the interrupt request */
@@ -417,7 +450,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        seglen = check_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len);
        if (seglen < 1)
                return -EINVAL;
-       setup_channel_list(dev, s, cmd->chanlist, seglen);
+       pcl816_ai_setup_chanlist(dev, cmd->chanlist, seglen);
        udelay(1);
 
        devpriv->ai_act_scan = 0;
@@ -586,28 +619,6 @@ check_channel_list(struct comedi_device *dev,
        return seglen;  /*  we can serve this with MUX logic */
 }
 
-static void
-setup_channel_list(struct comedi_device *dev,
-                  struct comedi_subdevice *s, unsigned int *chanlist,
-                  unsigned int seglen)
-{
-       struct pcl816_private *devpriv = dev->private;
-       unsigned int i;
-
-       for (i = 0; i < seglen; i++) {  /*  store range list to card */
-               devpriv->ai_act_chanlist[i] = CR_CHAN(chanlist[i]);
-               outb(CR_CHAN(chanlist[0]) & 0xf, dev->iobase + PCL816_MUX);
-               /* select gain */
-               outb(CR_RANGE(chanlist[0]), dev->iobase + PCL816_RANGE);
-       }
-
-       udelay(1);
-       /* select channel interval to scan */
-       outb(devpriv->ai_act_chanlist[0] |
-            (devpriv->ai_act_chanlist[seglen - 1] << 4),
-            dev->iobase + PCL816_MUX);
-}
-
 static int pcl816_ai_insn_read(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn,
@@ -621,10 +632,8 @@ static int pcl816_ai_insn_read(struct comedi_device *dev,
        /*  software trigger, DMA and INT off */
        outb(0, dev->iobase + PCL816_CONTROL);
 
-       /*  Set the input channel */
-       outb(chan, dev->iobase + PCL816_MUX);
-       /* select gain */
-       outb(range, dev->iobase + PCL816_RANGE);
+       pcl816_ai_set_chan_range(dev, chan, range);
+       pcl816_ai_set_chan_scan(dev, chan, chan);
 
        for (i = 0; i < insn->n; i++) {
                pcl816_ai_clear_eoc(dev);
@@ -672,7 +681,7 @@ static void pcl816_reset(struct comedi_device *dev)
        unsigned long timer_base = dev->iobase + PCL816_TIMER_BASE;
 
        outb(0, dev->iobase + PCL816_CONTROL);
-       outb(0, dev->iobase + PCL816_MUX);
+       pcl816_ai_set_chan_range(dev, 0, 0);
        pcl816_ai_clear_eoc(dev);
 
        /* Stop pacer */
@@ -680,8 +689,6 @@ static void pcl816_reset(struct comedi_device *dev)
        i8254_set_mode(timer_base, 0, 1, I8254_MODE0 | I8254_BINARY);
        i8254_set_mode(timer_base, 0, 0, I8254_MODE0 | I8254_BINARY);
 
-       outb(0, dev->iobase + PCL816_RANGE);
-
        /* set all digital outputs low */
        outb(0, dev->iobase + PCL816_DO_DI_LSB_REG);
        outb(0, dev->iobase + PCL816_DO_DI_MSB_REG);