staging: comedi: ni_65xx: tidy up the port<->chan conversions

Introduce some convienence macros to handle the port to channel,
channel to port, and channel mask calculations based on the 8
channels per port of the hardware.

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/ni_65xx.c b/drivers/staging/comedi/drivers/ni_65xx.c
index 742d3cd..5218e67 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_65xx.c
+++ b/drivers/staging/comedi/drivers/ni_65xx.c
@@ -110,8 +110,10 @@ except maybe the 6514.
 #define NI_65XX_WDOG_HI_LO_REG(x)      (0x48 + NI_65XX_PORT(x))
 #define NI_65XX_RTSI_ENA(x)            (0x49 + NI_65XX_PORT(x))
 
-#define NI_65XX_MAX_NUM_PORTS 12
-static const unsigned ni_65xx_channels_per_port = 8;
+#define NI_65XX_MAX_NUM_PORTS          12
+#define NI_65XX_PORT_TO_CHAN(x)                ((x) * 8)
+#define NI_65XX_CHAN_TO_PORT(x)                ((x) / 8)
+#define NI_65XX_CHAN_TO_MASK(x)                (1 << ((x) % 8))
 
 enum ni_65xx_boardid {
        BOARD_PCI6509,
@@ -258,11 +260,6 @@ static const struct ni_65xx_board ni_65xx_boards[] = {
        },
 };
 
-static inline unsigned ni_65xx_port_by_channel(unsigned channel)
-{
-       return channel / ni_65xx_channels_per_port;
-}
-
 static inline unsigned ni_65xx_total_num_ports(const struct ni_65xx_board
                                               *board)
 {
@@ -282,8 +279,8 @@ static int ni_65xx_dio_insn_config(struct comedi_device *dev,
        struct ni_65xx_private *devpriv = dev->private;
        unsigned long base_port = (unsigned long)s->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
-       unsigned int chan_mask = 1 << (chan % ni_65xx_channels_per_port);
-       unsigned port = base_port + ni_65xx_port_by_channel(chan);
+       unsigned int chan_mask = NI_65XX_CHAN_TO_MASK(chan);
+       unsigned port = base_port + NI_65XX_CHAN_TO_PORT(chan);
        unsigned int interval;
        unsigned int val;
 
@@ -345,23 +342,23 @@ static int ni_65xx_dio_insn_config(struct comedi_device *dev,
 
 static int ni_65xx_dio_insn_bits(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
-                                struct comedi_insn *insn, unsigned int *data)
+                                struct comedi_insn *insn,
+                                unsigned int *data)
 {
        const struct ni_65xx_board *board = comedi_board(dev);
-       unsigned long base_port = (unsigned long)s->private;
        struct ni_65xx_private *devpriv = dev->private;
-       int base_bitfield_channel;
+       unsigned long base_port = (unsigned long)s->private;
+       unsigned int base_chan = CR_CHAN(insn->chanspec);
+       int last_port_offset = NI_65XX_CHAN_TO_PORT(s->n_chan - 1);
        unsigned read_bits = 0;
-       int last_port_offset = ni_65xx_port_by_channel(s->n_chan - 1);
        int port_offset;
 
-       base_bitfield_channel = CR_CHAN(insn->chanspec);
-       for (port_offset = ni_65xx_port_by_channel(base_bitfield_channel);
+       for (port_offset = NI_65XX_CHAN_TO_PORT(base_chan);
             port_offset <= last_port_offset; port_offset++) {
                unsigned port = base_port + port_offset;
-               int base_port_channel = port_offset * ni_65xx_channels_per_port;
+               int base_port_channel = NI_65XX_PORT_TO_CHAN(port_offset);
                unsigned port_mask, port_data, port_read_bits;
-               int bitshift = base_port_channel - base_bitfield_channel;
+               int bitshift = base_port_channel - base_chan;
 
                if (bitshift >= 32)
                        break;
@@ -623,8 +620,7 @@ static int ni_65xx_auto_attach(struct comedi_device *dev,
        if (board->num_di_ports) {
                s->type = COMEDI_SUBD_DI;
                s->subdev_flags = SDF_READABLE;
-               s->n_chan =
-                   board->num_di_ports * ni_65xx_channels_per_port;
+               s->n_chan = NI_65XX_PORT_TO_CHAN(board->num_di_ports);
                s->range_table = &range_digital;
                s->maxdata = 1;
                s->insn_config = ni_65xx_dio_insn_config;
@@ -640,8 +636,7 @@ static int ni_65xx_auto_attach(struct comedi_device *dev,
        if (board->num_do_ports) {
                s->type = COMEDI_SUBD_DO;
                s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
-               s->n_chan =
-                   board->num_do_ports * ni_65xx_channels_per_port;
+               s->n_chan = NI_65XX_PORT_TO_CHAN(board->num_do_ports);
                s->range_table = &range_digital;
                s->maxdata = 1;
                s->insn_bits = ni_65xx_dio_insn_bits;
@@ -656,8 +651,7 @@ static int ni_65xx_auto_attach(struct comedi_device *dev,
        if (board->num_dio_ports) {
                s->type = COMEDI_SUBD_DIO;
                s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
-               s->n_chan =
-                   board->num_dio_ports * ni_65xx_channels_per_port;
+               s->n_chan = NI_65XX_PORT_TO_CHAN(board->num_dio_ports);
                s->range_table = &range_digital;
                s->maxdata = 1;
                s->insn_config = ni_65xx_dio_insn_config;