staging: comedi: 8255: refactor how the (*io) function works

Currently, all users of is module that use the default (*io) function
pass an 'iobase' to subdev_8255_init() of the form:

  dev->iobase + OFFSET_TO_8255_BASE_REG

Now that the (*io) callback includes the comedi_device 'dev' pointer
the 'dev->iobase' does not need to be included.

Modify the default (*io) function, subdev_8255_io(), to automatically
add the dev->iobase to the address when reading/writing the port.

For aesthetics, rename the subdevice private data member to 'regbase'.
Also, rename the local variables in this module that are used to
access this member.

Add a comment in dev_8255_attach() about the 'iobase' that is passed
to subdev_8255_init(). For manually attached 8255 devices the io
region is requested with __comedi_request_region() which does not
set dev->iobase. For these devices the 'regbase' is actually the
'iobase'.

Remove the, now unnecessary, dev->iobase from all the callers of
subdev_8255_init(). There are a couple drivers that only passed the
dev->iobase. For those drivers pass a 'regbase' of 0x00.

Note that the das16m1 driver is a bit goofy. The devpriv->extra_iobase
is requested using __comedi_request_region() which does not set the
dev->iobase. But the starting address passed is dev->iobase + DAS16M1_82C55
so a 'regbase' of DAS16M1_82C55 is passed to subdev_8255_init().

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/8255.c

@@ -93,29 +93,29 @@ I/O port base address can be found in the output of 'lspci -v'.
 #define CR_CW		0x80
 
 struct subdev_8255_private {
-	unsigned long iobase;
+	unsigned long regbase;
 	int (*io)(struct comedi_device *, int, int, int, unsigned long);
 };
 
 static int subdev_8255_io(struct comedi_device *dev,
-			  int dir, int port, int data, unsigned long iobase)
+			  int dir, int port, int data, unsigned long regbase)
 {
 	if (dir) {
-		outb(data, iobase + port);
+		outb(data, dev->iobase + regbase + port);
 		return 0;
 	}
-	return inb(iobase + port);
+	return inb(dev->iobase + regbase + port);
 }
 
 void subdev_8255_interrupt(struct comedi_device *dev,
 			   struct comedi_subdevice *s)
 {
 	struct subdev_8255_private *spriv = s->private;
-	unsigned long iobase = spriv->iobase;
+	unsigned long regbase = spriv->regbase;
 	unsigned short d;
 
-	d = spriv->io(dev, 0, _8255_DATA, 0, iobase);
-	d |= (spriv->io(dev, 0, _8255_DATA + 1, 0, iobase) << 8);
+	d = spriv->io(dev, 0, _8255_DATA, 0, regbase);
+	d |= (spriv->io(dev, 0, _8255_DATA + 1, 0, regbase) << 8);
 
 	comedi_buf_put(s, d);
 	s->async->events |= COMEDI_CB_EOS;
@@ -130,25 +130,25 @@ static int subdev_8255_insn(struct comedi_device *dev,
 			    unsigned int *data)
 {
 	struct subdev_8255_private *spriv = s->private;
-	unsigned long iobase = spriv->iobase;
+	unsigned long regbase = spriv->regbase;
 	unsigned int mask;
 	unsigned int v;
 
 	mask = comedi_dio_update_state(s, data);
 	if (mask) {
 		if (mask & 0xff)
-			spriv->io(dev, 1, _8255_DATA, s->state & 0xff, iobase);
+			spriv->io(dev, 1, _8255_DATA, s->state & 0xff, regbase);
 		if (mask & 0xff00)
 			spriv->io(dev, 1, _8255_DATA + 1,
-				  (s->state >> 8) & 0xff, iobase);
+				  (s->state >> 8) & 0xff, regbase);
 		if (mask & 0xff0000)
 			spriv->io(dev, 1, _8255_DATA + 2,
-				  (s->state >> 16) & 0xff, iobase);
+				  (s->state >> 16) & 0xff, regbase);
 	}
 
-	v = spriv->io(dev, 0, _8255_DATA, 0, iobase);
-	v |= (spriv->io(dev, 0, _8255_DATA + 1, 0, iobase) << 8);
-	v |= (spriv->io(dev, 0, _8255_DATA + 2, 0, iobase) << 16);
+	v = spriv->io(dev, 0, _8255_DATA, 0, regbase);
+	v |= (spriv->io(dev, 0, _8255_DATA + 1, 0, regbase) << 8);
+	v |= (spriv->io(dev, 0, _8255_DATA + 2, 0, regbase) << 16);
 
 	data[1] = v;
 
@@ -159,7 +159,7 @@ static void subdev_8255_do_config(struct comedi_device *dev,
 				  struct comedi_subdevice *s)
 {
 	struct subdev_8255_private *spriv = s->private;
-	unsigned long iobase = spriv->iobase;
+	unsigned long regbase = spriv->regbase;
 	int config;
 
 	config = CR_CW;
@@ -173,7 +173,7 @@ static void subdev_8255_do_config(struct comedi_device *dev,
 	if (!(s->io_bits & 0xf00000))
 		config |= CR_C_HI_IO;
 
-	spriv->io(dev, 1, _8255_CR, config, iobase);
+	spriv->io(dev, 1, _8255_CR, config, regbase);
 }
 
 static int subdev_8255_insn_config(struct comedi_device *dev,
@@ -264,7 +264,7 @@ static int subdev_8255_cancel(struct comedi_device *dev,
 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
 		     int (*io)(struct comedi_device *,
 			       int, int, int, unsigned long),
-		     unsigned long iobase)
+		     unsigned long regbase)
 {
 	struct subdev_8255_private *spriv;
 
@@ -272,7 +272,7 @@ int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
 	if (!spriv)
 		return -ENOMEM;
 
-	spriv->iobase	= iobase;
+	spriv->regbase	= regbase;
 	spriv->io	= io ? io : subdev_8255_io;
 
 	s->type		= COMEDI_SUBD_DIO;
@@ -292,11 +292,11 @@ EXPORT_SYMBOL_GPL(subdev_8255_init);
 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
 			 int (*io)(struct comedi_device *,
 				   int, int, int, unsigned long),
-			 unsigned long iobase)
+			 unsigned long regbase)
 {
 	int ret;
 
-	ret = subdev_8255_init(dev, s, io, iobase);
+	ret = subdev_8255_init(dev, s, io, regbase);
 	if (ret)
 		return ret;
 
@@ -319,8 +319,8 @@ static int dev_8255_attach(struct comedi_device *dev,
 			   struct comedi_devconfig *it)
 {
 	struct comedi_subdevice *s;
-	int ret;
 	unsigned long iobase;
+	int ret;
 	int i;
 
 	for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
@@ -341,6 +341,13 @@ static int dev_8255_attach(struct comedi_device *dev,
 		s = &dev->subdevices[i];
 		iobase = it->options[i];
 
+		/*
+		 * __comedi_request_region() does not set dev->iobase.
+		 *
+		 * For 8255 devices that are manually attached using
+		 * comedi_config, the 'iobase' is the actual I/O port
+		 * base address of the chip.
+		 */
 		ret = __comedi_request_region(dev, iobase, _8255_SIZE);
 		if (ret) {
 			s->type = COMEDI_SUBD_UNUSED;
@@ -364,7 +371,7 @@ static void dev_8255_detach(struct comedi_device *dev)
 		s = &dev->subdevices[i];
 		if (s->type != COMEDI_SUBD_UNUSED) {
 			spriv = s->private;
-			release_region(spriv->iobase, _8255_SIZE);
+			release_region(spriv->regbase, _8255_SIZE);
 		}
 	}
 }

drivers/staging/comedi/drivers/8255.h

@@ -24,11 +24,11 @@
 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
 		     int (*io)(struct comedi_device *,
 			       int, int, int, unsigned long),
-		     unsigned long iobase);
+		     unsigned long regbase);
 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
 			 int (*io)(struct comedi_device *,
 				   int, int, int, unsigned long),
-			 unsigned long iobase);
+			 unsigned long regbase);
 void subdev_8255_interrupt(struct comedi_device *dev,
 			   struct comedi_subdevice *s);
 

drivers/staging/comedi/drivers/8255_pci.c

@@ -247,15 +247,11 @@ static int pci_8255_auto_attach(struct comedi_device *dev,
 		return ret;
 
 	for (i = 0; i < board->n_8255; i++) {
-		unsigned long iobase;
-
 		s = &dev->subdevices[i];
-		if (is_mmio) {
+		if (is_mmio)
 			ret = subdev_8255_init(dev, s, pci_8255_mmio, i * 4);
-		} else {
-			iobase = dev->iobase + (i * 4);
-			ret = subdev_8255_init(dev, s, NULL, iobase);
-		}
+		else
+			ret = subdev_8255_init(dev, s, NULL, i * 4);
 		if (ret)
 			return ret;
 	}

drivers/staging/comedi/drivers/adv_pci_dio.c

@@ -1132,7 +1132,6 @@ static int pci_dio_auto_attach(struct comedi_device *dev,
 		for (j = 0; j < this_board->sdio[i].regs; j++) {
 			s = &dev->subdevices[subdev];
 			ret = subdev_8255_init(dev, s, NULL,
-					       dev->iobase +
 					       this_board->sdio[i].addr +
 					       SIZE_8255 * j);
 			if (ret)

drivers/staging/comedi/drivers/aio_aio12_8.c

@@ -244,8 +244,7 @@ static int aio_aio12_8_attach(struct comedi_device *dev,
 
 	s = &dev->subdevices[2];
 	/* 8255 Digital i/o subdevice */
-	ret = subdev_8255_init(dev, s, NULL,
-			       dev->iobase + AIO12_8_8255_BASE_REG);
+	ret = subdev_8255_init(dev, s, NULL, AIO12_8_8255_BASE_REG);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/amplc_pc236_common.c

@@ -160,7 +160,7 @@ int amplc_pc236_common_attach(struct comedi_device *dev, unsigned long iobase,
 
 	s = &dev->subdevices[0];
 	/* digital i/o subdevice (8255) */
-	ret = subdev_8255_init(dev, s, NULL, iobase);
+	ret = subdev_8255_init(dev, s, NULL, 0x00);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/amplc_pci230.c

@@ -2794,8 +2794,7 @@ static int pci230_attach_common(struct comedi_device *dev,
 	s = &dev->subdevices[2];
 	/* digital i/o subdevice */
 	if (thisboard->have_dio) {
-		rc = subdev_8255_init(dev, s, NULL,
-				      dev->iobase + PCI230_PPI_X_BASE);
+		rc = subdev_8255_init(dev, s, NULL, PCI230_PPI_X_BASE);
 		if (rc)
 			return rc;
 	} else {

drivers/staging/comedi/drivers/cb_pcidas.c

@@ -1528,7 +1528,7 @@ static int cb_pcidas_auto_attach(struct comedi_device *dev,
 
 	/* 8255 */
 	s = &dev->subdevices[2];
-	ret = subdev_8255_init(dev, s, NULL, dev->iobase + DIO_8255);
+	ret = subdev_8255_init(dev, s, NULL, DIO_8255);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/cb_pcidda.c

@@ -378,7 +378,7 @@ static int cb_pcidda_auto_attach(struct comedi_device *dev,
 	/* two 8255 digital io subdevices */
 	for (i = 0; i < 2; i++) {
 		s = &dev->subdevices[1 + i];
-		ret = subdev_8255_init(dev, s, NULL, dev->iobase + (i * 4));
+		ret = subdev_8255_init(dev, s, NULL, i * 4);
 		if (ret)
 			return ret;
 	}

drivers/staging/comedi/drivers/cb_pcimdas.c

@@ -252,7 +252,7 @@ static int cb_pcimdas_auto_attach(struct comedi_device *dev,
 
 	s = &dev->subdevices[2];
 	/* digital i/o subdevice */
-	ret = subdev_8255_init(dev, s, NULL, dev->iobase);
+	ret = subdev_8255_init(dev, s, NULL, 0x00);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/cb_pcimdda.c

@@ -182,8 +182,7 @@ static int cb_pcimdda_auto_attach(struct comedi_device *dev,
 
 	s = &dev->subdevices[1];
 	/* digital i/o subdevice */
-	ret = subdev_8255_init(dev, s, NULL,
-			dev->iobase + PCIMDDA_8255_BASE_REG);
+	ret = subdev_8255_init(dev, s, NULL, PCIMDDA_8255_BASE_REG);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/das08.c

@@ -536,8 +536,7 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase)
 	s = &dev->subdevices[4];
 	/* 8255 */
 	if (thisboard->i8255_offset != 0) {
-		ret = subdev_8255_init(dev, s, NULL,
-				       dev->iobase + thisboard->i8255_offset);
+		ret = subdev_8255_init(dev, s, NULL, thisboard->i8255_offset);
 		if (ret)
 			return ret;
 	} else {

drivers/staging/comedi/drivers/das16.c

@@ -1191,8 +1191,7 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	/* 8255 Digital I/O subdevice */
 	if (board->has_8255) {
 		s = &dev->subdevices[4];
-		ret = subdev_8255_init(dev, s, NULL,
-				       dev->iobase + board->i8255_offset);
+		ret = subdev_8255_init(dev, s, NULL, board->i8255_offset);
 		if (ret)
 			return ret;
 	}

drivers/staging/comedi/drivers/das16m1.c

@@ -608,7 +608,7 @@ static int das16m1_attach(struct comedi_device *dev,
 
 	s = &dev->subdevices[3];
 	/* 8255 */
-	ret = subdev_8255_init(dev, s, NULL, devpriv->extra_iobase);
+	ret = subdev_8255_init(dev, s, NULL, DAS16M1_82C55);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/ni_atmio16d.c

@@ -722,7 +722,7 @@ static int atmio16d_attach(struct comedi_device *dev,
 	/* 8255 subdevice */
 	s = &dev->subdevices[3];
 	if (board->has_8255) {
-		ret = subdev_8255_init(dev, s, NULL, dev->iobase);
+		ret = subdev_8255_init(dev, s, NULL, 0x00);
 		if (ret)
 			return ret;
 	} else {

drivers/staging/comedi/drivers/ni_daq_dio24.c

@@ -59,7 +59,7 @@ static int dio24_auto_attach(struct comedi_device *dev,
 
 	/* 8255 dio */
 	s = &dev->subdevices[0];
-	ret = subdev_8255_init(dev, s, NULL, dev->iobase);
+	ret = subdev_8255_init(dev, s, NULL, 0x00);
 	if (ret)
 		return ret;
 

drivers/staging/comedi/drivers/ni_labpc.c

@@ -1405,8 +1405,7 @@ int labpc_common_attach(struct comedi_device *dev,
 		ret = subdev_8255_init(dev, s, labpc_8255_mmio,
 				       DIO_BASE_REG);
 	} else {
-		ret = subdev_8255_init(dev, s, NULL,
-				       dev->iobase + DIO_BASE_REG);
+		ret = subdev_8255_init(dev, s, NULL, DIO_BASE_REG);
 	}
 	if (ret)
 		return ret;

drivers/staging/comedi/drivers/pcl724.c

@@ -133,8 +133,7 @@ static int pcl724_attach(struct comedi_device *dev,
 			ret = subdev_8255_init(dev, s, pcl724_8255mapped_io,
 					       iobase);
 		} else {
-			iobase = dev->iobase + (i * SIZE_8255);
-			ret = subdev_8255_init(dev, s, NULL, iobase);
+			ret = subdev_8255_init(dev, s, NULL, i * SIZE_8255);
 		}
 		if (ret)
 			return ret;

drivers/staging/comedi/drivers/pcm3724.c

@@ -211,8 +211,7 @@ static int pcm3724_attach(struct comedi_device *dev,
 
 	for (i = 0; i < dev->n_subdevices; i++) {
 		s = &dev->subdevices[i];
-		ret = subdev_8255_init(dev, s, NULL,
-				       dev->iobase + SIZE_8255 * i);
+		ret = subdev_8255_init(dev, s, NULL, i * SIZE_8255);
 		if (ret)
 			return ret;
 		s->insn_config = subdev_3724_insn_config;