staging: comedi: ni_at_a2150: convert driver to use the comedi_8254 module

The hardware supported by this driver includes an 8254 timer. For aesthetics,
convert it to use the comedi_8254 module to provide support for the 8254 timer.
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/Kconfig

@@ -469,6 +469,7 @@ config COMEDI_ADQ12B
 config COMEDI_NI_AT_A2150
 	tristate "NI AT-A2150 ISA card support"
 	select COMEDI_ISADMA if ISA_DMA_API
+	select COMEDI_8254
 	---help---
 	  Enable support for National Instruments AT-A2150 cards
 

drivers/staging/comedi/drivers/ni_at_a2150.c

@@ -68,7 +68,7 @@ TRIG_WAKE_EOS
 
 #include "comedi_isadma.h"
 #include "comedi_fc.h"
-#include "8253.h"
+#include "comedi_8254.h"
 
 #define A2150_DMA_BUFFER_SIZE	0xff00	/*  size in bytes of dma buffer */
 
@@ -110,8 +110,6 @@ TRIG_WAKE_EOS
 #define   DMA_INTR_EN_BIT 		0x800	/*  enable interrupt on dma terminal count */
 #define   DMA_DEM_EN_BIT	0x1000	/*  enables demand mode dma */
 #define I8253_BASE_REG		0x14
-#define I8253_MODE_REG		0x17
-#define   HW_COUNT_DISABLE		0x30	/*  disable hardware counting of conversions */
 
 struct a2150_board {
 	const char *name;
@@ -488,7 +486,6 @@ static int a2150_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	struct comedi_isadma_desc *desc = &dma->desc[0];
 	struct comedi_async *async = s->async;
 	struct comedi_cmd *cmd = &async->cmd;
-	unsigned long timer_base = dev->iobase + I8253_BASE_REG;
 	unsigned int old_config_bits = devpriv->config_bits;
 	unsigned int trigger_bits;
 
@@ -547,8 +544,7 @@ static int a2150_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);
 
 	/*  may need to wait 72 sampling periods if timing was changed */
-	i8254_set_mode(timer_base, 0, 2, I8254_MODE0 | I8254_BINARY);
-	i8254_write(timer_base, 0, 2, 72);
+	comedi_8254_load(dev->pacer, 2, 72, I8254_MODE0 | I8254_BINARY);
 
 	/*  setup start triggering */
 	trigger_bits = 0;
@@ -726,6 +722,11 @@ static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	/* an IRQ and DMA are required to support async commands */
 	a2150_alloc_irq_and_dma(dev, it);
 
+	dev->pacer = comedi_8254_init(dev->iobase + I8253_BASE_REG,
+				      0, I8254_IO8, 0);
+	if (!dev->pacer)
+		return -ENOMEM;
+
 	ret = comedi_alloc_subdevices(dev, 1);
 	if (ret)
 		return ret;
@@ -747,10 +748,6 @@ static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		s->cancel = a2150_cancel;
 	}
 
-	/* need to do this for software counting of completed conversions, to
-	 * prevent hardware count from stopping acquisition */
-	outw(HW_COUNT_DISABLE, dev->iobase + I8253_MODE_REG);
-
 	/*  set card's irq and dma levels */
 	outw(devpriv->irq_dma_bits, dev->iobase + IRQ_DMA_CNTRL_REG);