staging: comedi: pcmmio: setup irq routing during (*attach)

To use interrupts the IRQ routing must be configured and interrupts
enabled. Currently both steps are being handled in pcmmio_start_intr().

Move the code that sets the IRQ routing into the attach of the board.
At this point interrupts are still disabled. The enable and polarity
bits just need to be set in pcmmio_start_intr() to enable them.
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>

drivers/staging/comedi/drivers/pcmmio.c

@@ -90,6 +90,8 @@ Configuration Options:
 #define PCMMIO_AI_CMD_ODD_CHAN			(1 << 6)
 #define PCMMIO_AI_CMD_CHAN_SEL(x)		(((x) & 0x3) << 4)
 #define PCMMIO_AI_CMD_RANGE(x)			(((x) & 0x3) << 2)
+#define PCMMIO_RESOURCE_REG			0x02
+#define PCMMIO_RESOURCE_IRQ(x)			(((x) & 0xf) << 0)
 #define PCMMIO_AI_STATUS_REG			0x03
 #define PCMMIO_AI_STATUS_DATA_READY		(1 << 7)
 #define PCMMIO_AI_STATUS_DATA_DMA_PEND		(1 << 6)
@@ -99,7 +101,10 @@ Configuration Options:
 #define PCMMIO_AI_STATUS_REG_SEL		(1 << 3)
 #define PCMMIO_AI_STATUS_CMD_DRQ_ENA		(1 << 1)
 #define PCMMIO_AI_STATUS_IRQ_ENA		(1 << 0)
-#define PCMMIO_AI_RESOURCE_REG			0x03
+#define PCMMIO_AI_RES_ENA_REG			0x03
+#define PCMMIO_AI_RES_ENA_CMD_REG_ACCESS	(0 << 3)
+#define PCMMIO_AI_RES_ENA_AI_RES_ACCESS		(1 << 3)
+#define PCMMIO_AI_RES_ENA_DIO_RES_ACCESS	(1 << 4)
 #define PCMMIO_AI_2ND_ADC_OFFSET		0x04
 
 #define PCMMIO_AO_LSB_REG			0x08
@@ -462,23 +467,6 @@ static int pcmmio_start_intr(struct comedi_device *dev,
 		bits &= ((0x1 << 24) - 1) << 0;
 		devpriv->enabled_mask = bits;
 
-		{
-			/*
-			 * the below code configures the board
-			 * to use a specific IRQ from 0-15.
-			 */
-			unsigned char b;
-			/*
-			 * set resource enable register
-			 * to enable IRQ operation
-			 */
-			outb(1 << 4, dev->iobase + 3);
-			/* set bits 0-3 of b to the irq number from 0-15 */
-			b = dev->irq & ((1 << 4) - 1);
-			outb(b, dev->iobase + 2);
-			/* done, we told the board what irq to use */
-		}
-
 		switch_page(dev, PCMMIO_PAGE_ENAB);
 		for (port = firstport; port < firstport + nports; ++port) {
 			unsigned enab, pol;
@@ -814,8 +802,15 @@ static int pcmmio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	if (it->options[1]) {
 		ret = request_irq(it->options[1], interrupt_pcmmio, 0,
 				  dev->board_name, dev);
-		if (ret == 0)
+		if (ret == 0) {
 			dev->irq = it->options[1];
+
+			/* configure the interrupt routing on the board */
+			outb(PCMMIO_AI_RES_ENA_DIO_RES_ACCESS,
+			     dev->iobase + PCMMIO_AI_RES_ENA_REG);
+			outb(PCMMIO_RESOURCE_IRQ(dev->irq),
+			     dev->iobase + PCMMIO_RESOURCE_REG);
+		}
 	}
 
 	ret = comedi_alloc_subdevices(dev, 4);
@@ -832,9 +827,10 @@ static int pcmmio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	s->insn_read	= pcmmio_ai_insn_read;
 
 	/* initialize the resource enable register by clearing it */
-	outb(0, dev->iobase + PCMMIO_AI_RESOURCE_REG);
-	outb(0,
-	     dev->iobase + PCMMIO_AI_2ND_ADC_OFFSET + PCMMIO_AI_RESOURCE_REG);
+	outb(PCMMIO_AI_RES_ENA_CMD_REG_ACCESS,
+	     dev->iobase + PCMMIO_AI_RES_ENA_REG);
+	outb(PCMMIO_AI_RES_ENA_CMD_REG_ACCESS,
+	     dev->iobase + PCMMIO_AI_RES_ENA_REG + PCMMIO_AI_2ND_ADC_OFFSET);
 
 	/* Analog Output subdevice */
 	s = &dev->subdevices[1];