staging: comedi: adl_pci9118: introduce pci9118_ai_start_conv()

Writing any value to the "software trigger" register generates a trigger
pulse to start an A/D conversion. Introduce a helper function to clarify
this. For aesthetics, rename the define used for the register.

According to the datasheet the extra delay is not needed after starting
the conversion. Remove it.

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/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index 6fb46cb03594b3d985590b433dac1b94d0282d59..5eca67f13cc7b99f39ef3b36887c030943dfc09e 100644 (file)
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -130,8 +130,8 @@
 #define PCI9118_AI_CTRL_INT            (1 << 1)  /* 1=enable interrupt */
 #define PCI9118_AI_CTRL_DMA            (1 << 0)  /* 1=enable DMA */
 #define PCI9118_DIO_REG                        0x1c
+#define PCI9118_SOFTTRG_REG            0x20
 
-#define PCI9118_SOFTTRG        0x20    /* W:   soft trigger for A/D */
 #define PCI9118_GAIN   0x24    /* W:   A/D gain/channel register */
 #define PCI9118_BURST  0x28    /* W:   A/D burst number register */
 #define PCI9118_SCANMOD        0x2c    /* W:   A/D auto scan mode */
@@ -485,6 +485,12 @@ static int pci9118_ai_eoc(struct comedi_device *dev,
        return -EBUSY;
 }
 
+static void pci9118_ai_start_conv(struct comedi_device *dev)
+{
+       /* writing any value triggers an A/D conversion */
+       outl(0, dev->iobase + PCI9118_SOFTTRG_REG);
+}
+
 static int pci9118_insn_read_ai(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_insn *insn, unsigned int *data)
@@ -511,8 +517,7 @@ static int pci9118_insn_read_ai(struct comedi_device *dev,
        outl(0, dev->iobase + PCI9118_DELFIFO); /* flush FIFO */
 
        for (n = 0; n < insn->n; n++) {
-               outl(0, dev->iobase + PCI9118_SOFTTRG); /* start conversion */
-               udelay(2);
+               pci9118_ai_start_conv(dev);
 
                ret = comedi_timeout(dev, s, insn, pci9118_ai_eoc, 0);
                if (ret) {