staging: comedi: addi_apci_3120: introduce apci3120_clr_timer2_interrupt()

A dummy read of APCI3120_CTR0_REG clears the timer 2 interrupt. Introduce a
helper function to clarify this.

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/addi-data/hwdrv_apci3120.c b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
index 3683c9c..6f547ee 100644 (file)
--- a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
+++ b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
@@ -130,7 +130,6 @@ This program is distributed in the hope that it will be useful, but WITHOUT ANY
 #define APCI3120_DISABLE_TIMER_INT     (~APCI3120_ENABLE_TIMER_INT)
 #define APCI3120_WRITE_MODE_SELECT     0x0e
 
-#define APCI3120_TIMER_STATUS_REGISTER 0x0d
 #define APCI3120_RD_STATUS             0x02
 #define APCI3120_ENABLE_WATCHDOG       0x20
 #define APCI3120_DISABLE_WATCHDOG      (~APCI3120_ENABLE_WATCHDOG)
@@ -691,8 +690,8 @@ static int apci3120_cyclic_ai(int mode,
                        /* Set the scan stop count (not sure about the -2) */
                        apci3120_timer_write(dev, 2, cmd->stop_arg - 2);
 
-                       /* (2) Reset FC_TIMER BIT  Clearing timer status register */
-                       inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
+                       apci3120_clr_timer2_interrupt(dev);
+
                        /*  enable timer counter and disable watch dog */
                        devpriv->b_ModeSelectRegister =
                                (devpriv->
@@ -1067,7 +1066,6 @@ static irqreturn_t apci3120_interrupt(int irq, void *d)
        unsigned short int_daq;
        unsigned int int_amcc, ui_Check, i;
        unsigned short us_TmpValue;
-       unsigned char b_DummyRead;
 
        ui_Check = 1;
 
@@ -1087,8 +1085,8 @@ static irqreturn_t apci3120_interrupt(int irq, void *d)
                apci3120_exttrig_enable(dev, false);
                devpriv->b_ExttrigEnable = APCI3120_DISABLE;
        }
-       /* clear the timer 2 interrupt */
-       inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
+
+       apci3120_clr_timer2_interrupt(dev);
 
        if (int_amcc & MASTER_ABORT_INT)
                dev_err(dev->class_dev, "AMCC IRQ - MASTER DMA ABORT!\n");
@@ -1194,8 +1192,7 @@ static irqreturn_t apci3120_interrupt(int irq, void *d)
 
                }
 
-               b_DummyRead = inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
-
+               apci3120_clr_timer2_interrupt(dev);
        }
 
        if ((int_daq & 0x4) && (devpriv->b_InterruptMode == APCI3120_DMA_MODE)) {
@@ -1205,8 +1202,8 @@ static irqreturn_t apci3120_interrupt(int irq, void *d)
                        outl(APCI3120_CLEAR_WRITE_TC_INT,
                             devpriv->amcc + APCI3120_AMCC_OP_REG_INTCSR);
 
-                       /* Clears the timer status register */
-                       inw(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
+                       apci3120_clr_timer2_interrupt(dev);
+
                        /* do some data transfer */
                        apci3120_interrupt_dma(irq, d);
                } else {
@@ -1318,9 +1315,8 @@ static int apci3120_write_insn_timer(struct comedi_device *dev,
 
        switch (data[0]) {
        case APCI3120_START:
+               apci3120_clr_timer2_interrupt(dev);
 
-               /*  Reset FC_TIMER BIT */
-               inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
                if (devpriv->b_Timer2Mode == APCI3120_TIMER) {  /* start timer */
                        /* Enable Timer */
                        devpriv->b_ModeSelectRegister =
@@ -1382,9 +1378,7 @@ static int apci3120_write_insn_timer(struct comedi_device *dev,
 
                apci3120_timer_enable(dev, 2, false);
 
-               /*  Reset FC_TIMER BIT */
-               inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
-
+               apci3120_clr_timer2_interrupt(dev);
                break;
 
        case 2:         /* write new value to Timer */
@@ -1434,10 +1428,8 @@ static int apci3120_read_insn_timer(struct comedi_device *dev,
                us_StatusValue = inw(dev->iobase + APCI3120_RD_STATUS);
                us_StatusValue =
                        ((us_StatusValue & APCI3120_FC_TIMER) >> 12) & 1;
-               if (us_StatusValue == 1) {
-                       /*  RESET FC_TIMER BIT */
-                       inb(dev->iobase + APCI3120_TIMER_STATUS_REGISTER);
-               }
+               if (us_StatusValue == 1)
+                       apci3120_clr_timer2_interrupt(dev);
                data[0] = us_StatusValue;       /*  when data[0] = 1 then the watch dog has rundown */
        }
        return insn->n;

diff --git a/drivers/staging/comedi/drivers/addi_apci_3120.c b/drivers/staging/comedi/drivers/addi_apci_3120.c
index 8f7d9ef..ce94f90 100644 (file)
--- a/drivers/staging/comedi/drivers/addi_apci_3120.c
+++ b/drivers/staging/comedi/drivers/addi_apci_3120.c
@@ -155,6 +155,12 @@ static unsigned int apci3120_ns_to_timer(struct comedi_device *dev,
        return divisor;
 }
 
+static void apci3120_clr_timer2_interrupt(struct comedi_device *dev)
+{
+       /* a dummy read of APCI3120_CTR0_REG clears the timer 2 interrupt */
+       inb(dev->iobase + APCI3120_CTR0_REG);
+}
+
 static void apci3120_timer_write(struct comedi_device *dev,
                                 unsigned int timer, unsigned int val)
 {