staging: comedi: amplc_pci224: always cascade the 8254 timers

The 8254 timers are only used in this driver to generate the analog
output pacer. To simplify the driver, always cascade the timers.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
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/amplc_pci224.c b/drivers/staging/comedi/drivers/amplc_pci224.c
index 727fc22..37a81b7 100644 (file)
--- a/drivers/staging/comedi/drivers/amplc_pci224.c
+++ b/drivers/staging/comedi/drivers/amplc_pci224.c
@@ -841,51 +841,15 @@ pci224_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
        /* Step 4: fix up any arguments. */
 
        if (cmd->scan_begin_src == TRIG_TIMER) {
-               unsigned int div1, div2, round;
-               int round_mode = cmd->flags & TRIG_ROUND_MASK;
-
                tmp = cmd->scan_begin_arg;
-               /* Check whether to use a single timer. */
-               switch (round_mode) {
-               case TRIG_ROUND_NEAREST:
-               default:
-                       round = I8254_OSC_BASE_10MHZ / 2;
-                       break;
-               case TRIG_ROUND_DOWN:
-                       round = 0;
-                       break;
-               case TRIG_ROUND_UP:
-                       round = I8254_OSC_BASE_10MHZ - 1;
-                       break;
-               }
-               /* Be careful to avoid overflow! */
-               div2 = cmd->scan_begin_arg / I8254_OSC_BASE_10MHZ;
-               div2 += (round + cmd->scan_begin_arg % I8254_OSC_BASE_10MHZ) /
-                       I8254_OSC_BASE_10MHZ;
-               if (div2 <= 0x10000) {
-                       /* A single timer will suffice. */
-                       if (div2 < 2)
-                               div2 = 2;
-                       cmd->scan_begin_arg = div2 * I8254_OSC_BASE_10MHZ;
-                       if (cmd->scan_begin_arg < div2 ||
-                           cmd->scan_begin_arg < I8254_OSC_BASE_10MHZ) {
-                               /* Overflow! */
-                               cmd->scan_begin_arg = MAX_SCAN_PERIOD;
-                       }
-               } else {
-                       /* Use two timers. */
-                       div1 = devpriv->cached_div1;
-                       div2 = devpriv->cached_div2;
-                       i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
-                                                 &div1, &div2,
-                                                 &cmd->scan_begin_arg,
-                                                 round_mode);
-                       devpriv->cached_div1 = div1;
-                       devpriv->cached_div2 = div2;
-               }
+               /* Use two timers. */
+               i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
+                                         &devpriv->cached_div1,
+                                         &devpriv->cached_div2,
+                                         &cmd->scan_begin_arg,
+                                         cmd->flags);
                if (tmp != cmd->scan_begin_arg)
                        err++;
-
        }
 
        if (err)
@@ -906,70 +870,33 @@ static void pci224_ao_start_pacer(struct comedi_device *dev,
 {
        struct pci224_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;
-       unsigned int div1, div2, round;
-       unsigned int ns = cmd->scan_begin_arg;
-       int round_mode = cmd->flags & TRIG_ROUND_MASK;
 
-       /* Check whether to use a single timer. */
-       switch (round_mode) {
-       case TRIG_ROUND_NEAREST:
-       default:
-               round = I8254_OSC_BASE_10MHZ / 2;
-               break;
-       case TRIG_ROUND_DOWN:
-               round = 0;
-               break;
-       case TRIG_ROUND_UP:
-               round = I8254_OSC_BASE_10MHZ - 1;
-               break;
-       }
-       /* Be careful to avoid overflow! */
-       div2 = cmd->scan_begin_arg / I8254_OSC_BASE_10MHZ;
-       div2 += (round + cmd->scan_begin_arg % I8254_OSC_BASE_10MHZ) /
-               I8254_OSC_BASE_10MHZ;
-       if (div2 <= 0x10000) {
-               /* A single timer will suffice. */
-               if (div2 < 2)
-                       div2 = 2;
-               div2 &= 0xffff;
-               div1 = 1;       /* Flag that single timer to be used. */
-       } else {
-               /* Use two timers. */
-               div1 = devpriv->cached_div1;
-               div2 = devpriv->cached_div2;
-               i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
-                                        &div1, &div2,
-                                        &ns, round_mode);
-       }
+       /* Use two timers. */
+       i8253_cascade_ns_to_timer(I8254_OSC_BASE_10MHZ,
+                                 &devpriv->cached_div1,
+                                 &devpriv->cached_div2,
+                                 &cmd->scan_begin_arg,
+                                 cmd->flags);
 
        /*
         * The output of timer Z2-0 will be used as the scan trigger
         * source.
         */
        /* Make sure Z2-0 is gated on.  */
-       outb(GAT_CONFIG(0, GAT_VCC),
-               devpriv->iobase1 + PCI224_ZGAT_SCE);
-       if (div1 == 1) {
-               /* Not cascading.  Z2-0 needs 10 MHz clock. */
-               outb(CLK_CONFIG(0, CLK_10MHZ),
-                       devpriv->iobase1 + PCI224_ZCLK_SCE);
-       } else {
-               /* Cascading with Z2-2. */
-               /* Make sure Z2-2 is gated on.  */
-               outb(GAT_CONFIG(2, GAT_VCC),
-                       devpriv->iobase1 + PCI224_ZGAT_SCE);
-               /* Z2-2 needs 10 MHz clock. */
-               outb(CLK_CONFIG(2, CLK_10MHZ),
-                       devpriv->iobase1 + PCI224_ZCLK_SCE);
-               /* Load Z2-2 mode (2) and counter (div1). */
-               i8254_load(devpriv->iobase1 + PCI224_Z2_CT0, 0,
-                               2, div1, 2);
-               /* Z2-0 is clocked from Z2-2's output. */
-               outb(CLK_CONFIG(0, CLK_OUTNM1),
-                       devpriv->iobase1 + PCI224_ZCLK_SCE);
-       }
+       outb(GAT_CONFIG(0, GAT_VCC), devpriv->iobase1 + PCI224_ZGAT_SCE);
+       /* Cascading with Z2-2. */
+       /* Make sure Z2-2 is gated on.  */
+       outb(GAT_CONFIG(2, GAT_VCC), devpriv->iobase1 + PCI224_ZGAT_SCE);
+       /* Z2-2 needs 10 MHz clock. */
+       outb(CLK_CONFIG(2, CLK_10MHZ), devpriv->iobase1 + PCI224_ZCLK_SCE);
+       /* Load Z2-2 mode (2) and counter (div1). */
+       i8254_load(devpriv->iobase1 + PCI224_Z2_CT0, 0,
+                       2, devpriv->cached_div1, 2);
+       /* Z2-0 is clocked from Z2-2's output. */
+       outb(CLK_CONFIG(0, CLK_OUTNM1), devpriv->iobase1 + PCI224_ZCLK_SCE);
        /* Load Z2-0 mode (2) and counter (div2). */
-       i8254_load(devpriv->iobase1 + PCI224_Z2_CT0, 0, 0, div2, 2);
+       i8254_load(devpriv->iobase1 + PCI224_Z2_CT0, 0,
+                  0, devpriv->cached_div2, 2);
 }
 
 static int pci224_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)