staging: comedi: rtd520: use normal bitfield functions

The `unsigned char chan_is_bipolar[]` member of `struct rtd_private` is
used with some macros as a packed array of 1-bit values that indicate
whether the corresponding entries in the hardware's "channel-gain" table
have been set to a bipolar (1) or unipolar (0) range, as the raw samples
from the hardware need to be cooked differently in each case.

Replace the declaration of the member with a standard Linux bitfield
using `DECLARE_BITFIELD()`, and replace the home-grown macros used
access the bitfield with the standard Linux non-atomic bitop functions,
`__set_bit()`, `__clear_bit()` and `test_bit()`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index 0ae2d6175471d4970a1b7f267581462684bb7842..44c8712ed9e05ddf939f1792dd452b94d2e7044f 100644 (file)
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -394,11 +394,8 @@ struct rtd_private {
        long ai_count;          /* total transfer size (samples) */
        int xfer_count;         /* # to transfer data. 0->1/2FIFO */
        int flags;              /* flag event modes */
-
-       unsigned char chan_is_bipolar[RTD_MAX_CHANLIST / 8];    /* bit array */
-
+       DECLARE_BITMAP(chan_is_bipolar, RTD_MAX_CHANLIST);
        unsigned int ao_readback[2];
-
        unsigned fifosz;
 };
 
@@ -407,14 +404,6 @@ struct rtd_private {
 #define DMA0_ACTIVE    0x02    /* DMA0 is active */
 #define DMA1_ACTIVE    0x04    /* DMA1 is active */
 
-/* Macros for accessing channel list bit array */
-#define CHAN_ARRAY_TEST(array, index) \
-       (((array)[(index)/8] >> ((index) & 0x7)) & 0x1)
-#define CHAN_ARRAY_SET(array, index) \
-       (((array)[(index)/8] |= 1 << ((index) & 0x7)))
-#define CHAN_ARRAY_CLEAR(array, index) \
-       (((array)[(index)/8] &= ~(1 << ((index) & 0x7))))
-
 /*
   Given a desired period and the clock period (both in ns),
   return the proper counter value (divider-1).
@@ -478,17 +467,17 @@ static unsigned short rtd_convert_chan_gain(struct comedi_device *dev,
                /* +-5 range */
                r |= 0x000;
                r |= (range & 0x7) << 4;
-               CHAN_ARRAY_SET(devpriv->chan_is_bipolar, index);
+               __set_bit(index, devpriv->chan_is_bipolar);
        } else if (range < board->range_uni10) {
                /* +-10 range */
                r |= 0x100;
                r |= ((range - board->range_bip10) & 0x7) << 4;
-               CHAN_ARRAY_SET(devpriv->chan_is_bipolar, index);
+               __set_bit(index, devpriv->chan_is_bipolar);
        } else {
                /* +10 range */
                r |= 0x200;
                r |= ((range - board->range_uni10) & 0x7) << 4;
-               CHAN_ARRAY_CLEAR(devpriv->chan_is_bipolar, index);
+               __clear_bit(index, devpriv->chan_is_bipolar);
        }
 
        switch (aref) {
@@ -619,7 +608,7 @@ static int rtd_ai_rinsn(struct comedi_device *dev,
                d = readw(devpriv->las1 + LAS1_ADC_FIFO);
                /*printk ("rtd520: Got 0x%x after %d usec\n", d, ii+1); */
                d = d >> 3;     /* low 3 bits are marker lines */
-               if (CHAN_ARRAY_TEST(devpriv->chan_is_bipolar, 0))
+               if (test_bit(0, devpriv->chan_is_bipolar))
                        /* convert to comedi unsigned data */
                        d = comedi_offset_munge(s, d);
                data[n] = d & s->maxdata;
@@ -651,8 +640,7 @@ static int ai_read_n(struct comedi_device *dev, struct comedi_subdevice *s,
 
                d = readw(devpriv->las1 + LAS1_ADC_FIFO);
                d = d >> 3;     /* low 3 bits are marker lines */
-               if (CHAN_ARRAY_TEST(devpriv->chan_is_bipolar,
-                                   s->async->cur_chan))
+               if (test_bit(s->async->cur_chan, devpriv->chan_is_bipolar))
                        /* convert to comedi unsigned data */
                        d = comedi_offset_munge(s, d);
                d &= s->maxdata;
@@ -681,8 +669,7 @@ static int ai_read_dregs(struct comedi_device *dev, struct comedi_subdevice *s)
                }
 
                d = d >> 3;     /* low 3 bits are marker lines */
-               if (CHAN_ARRAY_TEST(devpriv->chan_is_bipolar,
-                                   s->async->cur_chan))
+               if (test_bit(s->async->cur_chan, devpriv->chan_is_bipolar))
                        /* convert to comedi unsigned data */
                        d = comedi_offset_munge(s, d);
                d &= s->maxdata;