staging: comedi: amplc_dio200: use register offsets in subdevices

Replace the absolute, modified I/O base addresses in the private data
structures for the '8254' counter and 'intr' DIO subdevices with offsets
from the main I/O base address.  `dio200_subdev_intr_init()` now needs
the offset instead of the absolute address.  `dio200_subdev_8254_init()`
now only needs the offset instead of both the absolute address and the
offset.  The '8255' DIO subdevices are unaffected as they are handled by
the external "8255" module.

This change is not useful by itself but is an intermediate step for
later changes.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/amplc_dio200.c

@@ -421,20 +421,19 @@ struct dio200_private {
 };
 
 struct dio200_subdev_8254 {
-	unsigned long iobase;	/* Counter base address */
-	unsigned long clk_sce_iobase;	/* CLK_SCE base address */
-	unsigned long gat_sce_iobase;	/* GAT_SCE base address */
-	int which;		/* Bit 5 of CLK_SCE or GAT_SCE */
-	unsigned clock_src[3];	/* Current clock sources */
-	unsigned gate_src[3];	/* Current gate sources */
+	unsigned int ofs;		/* Counter base offset */
+	unsigned int clk_sce_ofs;	/* CLK_SCE base address */
+	unsigned int gat_sce_ofs;	/* GAT_SCE base address */
+	int which;			/* Bit 5 of CLK_SCE or GAT_SCE */
+	unsigned int clock_src[3];	/* Current clock sources */
+	unsigned int gate_src[3];	/* Current gate sources */
 	spinlock_t spinlock;
 };
 
 struct dio200_subdev_intr {
-	unsigned long iobase;
+	unsigned int ofs;
 	spinlock_t spinlock;
 	int active;
-	int has_int_sce;
 	unsigned int valid_isns;
 	unsigned int enabled_isns;
 	unsigned int stopcount;
@@ -502,11 +501,12 @@ dio200_subdev_intr_insn_bits(struct comedi_device *dev,
 			     struct comedi_subdevice *s,
 			     struct comedi_insn *insn, unsigned int *data)
 {
+	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_intr *subpriv = s->private;
 
-	if (subpriv->has_int_sce) {
+	if (layout->has_int_sce) {
 		/* Just read the interrupt status register.  */
-		data[1] = inb(subpriv->iobase) & subpriv->valid_isns;
+		data[1] = inb(dev->iobase + subpriv->ofs) & subpriv->valid_isns;
 	} else {
 		/* No interrupt status register. */
 		data[0] = 0;
@@ -521,12 +521,13 @@ dio200_subdev_intr_insn_bits(struct comedi_device *dev,
 static void dio200_stop_intr(struct comedi_device *dev,
 			     struct comedi_subdevice *s)
 {
+	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_intr *subpriv = s->private;
 
 	subpriv->active = 0;
 	subpriv->enabled_isns = 0;
-	if (subpriv->has_int_sce)
-		outb(0, subpriv->iobase);
+	if (layout->has_int_sce)
+		outb(0, dev->iobase + subpriv->ofs);
 }
 
 /*
@@ -537,6 +538,7 @@ static int dio200_start_intr(struct comedi_device *dev,
 {
 	unsigned int n;
 	unsigned isn_bits;
+	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_intr *subpriv = s->private;
 	struct comedi_cmd *cmd = &s->async->cmd;
 	int retval = 0;
@@ -556,8 +558,8 @@ static int dio200_start_intr(struct comedi_device *dev,
 		isn_bits &= subpriv->valid_isns;
 		/* Enable interrupt sources. */
 		subpriv->enabled_isns = isn_bits;
-		if (subpriv->has_int_sce)
-			outb(isn_bits, subpriv->iobase);
+		if (layout->has_int_sce)
+			outb(isn_bits, dev->iobase + subpriv->ofs);
 	}
 
 	return retval;
@@ -599,6 +601,7 @@ dio200_inttrig_start_intr(struct comedi_device *dev, struct comedi_subdevice *s,
 static int dio200_handle_read_intr(struct comedi_device *dev,
 				   struct comedi_subdevice *s)
 {
+	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_intr *subpriv = s->private;
 	unsigned triggered;
 	unsigned intstat;
@@ -610,7 +613,7 @@ static int dio200_handle_read_intr(struct comedi_device *dev,
 
 	spin_lock_irqsave(&subpriv->spinlock, flags);
 	oldevents = s->async->events;
-	if (subpriv->has_int_sce) {
+	if (layout->has_int_sce) {
 		/*
 		 * Collect interrupt sources that have triggered and disable
 		 * them temporarily.  Loop around until no extra interrupt
@@ -622,11 +625,11 @@ static int dio200_handle_read_intr(struct comedi_device *dev,
 		 * loop in case of misconfiguration.
 		 */
 		cur_enabled = subpriv->enabled_isns;
-		while ((intstat = (inb(subpriv->iobase) & subpriv->valid_isns
-				   & ~triggered)) != 0) {
+		while ((intstat = (inb(dev->iobase + subpriv->ofs) &
+				   subpriv->valid_isns & ~triggered)) != 0) {
 			triggered |= intstat;
 			cur_enabled &= ~triggered;
-			outb(cur_enabled, subpriv->iobase);
+			outb(cur_enabled, dev->iobase + subpriv->ofs);
 		}
 	} else {
 		/*
@@ -644,8 +647,8 @@ static int dio200_handle_read_intr(struct comedi_device *dev,
 		 * Reenable them NOW to minimize the time they are disabled.
 		 */
 		cur_enabled = subpriv->enabled_isns;
-		if (subpriv->has_int_sce)
-			outb(cur_enabled, subpriv->iobase);
+		if (layout->has_int_sce)
+			outb(cur_enabled, dev->iobase + subpriv->ofs);
 
 		if (subpriv->active) {
 			/*
@@ -851,9 +854,9 @@ static int dio200_subdev_intr_cmd(struct comedi_device *dev,
  */
 static int
 dio200_subdev_intr_init(struct comedi_device *dev, struct comedi_subdevice *s,
-			unsigned long iobase, unsigned valid_isns,
-			int has_int_sce)
+			unsigned int offset, unsigned valid_isns)
 {
+	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_intr *subpriv;
 
 	subpriv = kzalloc(sizeof(*subpriv), GFP_KERNEL);
@@ -861,18 +864,18 @@ dio200_subdev_intr_init(struct comedi_device *dev, struct comedi_subdevice *s,
 		dev_err(dev->class_dev, "error! out of memory!\n");
 		return -ENOMEM;
 	}
-	subpriv->iobase = iobase;
-	subpriv->has_int_sce = has_int_sce;
+	subpriv->ofs = offset;
 	subpriv->valid_isns = valid_isns;
 	spin_lock_init(&subpriv->spinlock);
 
-	if (has_int_sce)
-		outb(0, subpriv->iobase);	/* Disable interrupt sources. */
+	if (layout->has_int_sce)
+		/* Disable interrupt sources. */
+		outb(0, dev->iobase + subpriv->ofs);
 
 	s->private = subpriv;
 	s->type = COMEDI_SUBD_DI;
 	s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
-	if (has_int_sce) {
+	if (layout->has_int_sce) {
 		s->n_chan = DIO200_MAX_ISNS;
 		s->len_chanlist = DIO200_MAX_ISNS;
 	} else {
@@ -936,7 +939,7 @@ dio200_subdev_8254_read(struct comedi_device *dev, struct comedi_subdevice *s,
 	unsigned long flags;
 
 	spin_lock_irqsave(&subpriv->spinlock, flags);
-	data[0] = i8254_read(subpriv->iobase, 0, chan);
+	data[0] = i8254_read(dev->iobase + subpriv->ofs, 0, chan);
 	spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
 	return 1;
@@ -954,7 +957,7 @@ dio200_subdev_8254_write(struct comedi_device *dev, struct comedi_subdevice *s,
 	unsigned long flags;
 
 	spin_lock_irqsave(&subpriv->spinlock, flags);
-	i8254_write(subpriv->iobase, 0, chan, data[0]);
+	i8254_write(dev->iobase + subpriv->ofs, 0, chan, data[0]);
 	spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
 	return 1;
@@ -982,7 +985,7 @@ dio200_subdev_8254_set_gate_src(struct comedi_device *dev,
 
 	subpriv->gate_src[counter_number] = gate_src;
 	byte = GAT_SCE(subpriv->which, counter_number, gate_src);
-	outb(byte, subpriv->gat_sce_iobase);
+	outb(byte, dev->iobase + subpriv->gat_sce_ofs);
 
 	return 0;
 }
@@ -1028,7 +1031,7 @@ dio200_subdev_8254_set_clock_src(struct comedi_device *dev,
 
 	subpriv->clock_src[counter_number] = clock_src;
 	byte = CLK_SCE(subpriv->which, counter_number, clock_src);
-	outb(byte, subpriv->clk_sce_iobase);
+	outb(byte, dev->iobase + subpriv->clk_sce_ofs);
 
 	return 0;
 }
@@ -1071,12 +1074,13 @@ dio200_subdev_8254_config(struct comedi_device *dev, struct comedi_subdevice *s,
 	spin_lock_irqsave(&subpriv->spinlock, flags);
 	switch (data[0]) {
 	case INSN_CONFIG_SET_COUNTER_MODE:
-		ret = i8254_set_mode(subpriv->iobase, 0, chan, data[1]);
+		ret = i8254_set_mode(dev->iobase + subpriv->ofs, 0, chan,
+				     data[1]);
 		if (ret < 0)
 			ret = -EINVAL;
 		break;
 	case INSN_CONFIG_8254_READ_STATUS:
-		data[1] = i8254_status(subpriv->iobase, 0, chan);
+		data[1] = i8254_status(dev->iobase + subpriv->ofs, 0, chan);
 		break;
 	case INSN_CONFIG_SET_GATE_SRC:
 		ret = dio200_subdev_8254_set_gate_src(dev, s, chan, data[2]);
@@ -1114,13 +1118,10 @@ dio200_subdev_8254_config(struct comedi_device *dev, struct comedi_subdevice *s,
 
 /*
  * This function initializes an '8254' counter subdevice.
- *
- * Note: iobase is the base address of the board, not the subdevice;
- * offset is the offset to the 8254 chip.
  */
 static int
 dio200_subdev_8254_init(struct comedi_device *dev, struct comedi_subdevice *s,
-			unsigned long iobase, unsigned offset)
+			unsigned int offset)
 {
 	const struct dio200_layout *layout = dio200_dev_layout(dev);
 	struct dio200_subdev_8254 *subpriv;
@@ -1142,20 +1143,18 @@ dio200_subdev_8254_init(struct comedi_device *dev, struct comedi_subdevice *s,
 	s->insn_config = dio200_subdev_8254_config;
 
 	spin_lock_init(&subpriv->spinlock);
-	subpriv->iobase = offset + iobase;
+	subpriv->ofs = offset;
 	if (layout->has_clk_gat_sce) {
 		/* Derive CLK_SCE and GAT_SCE register offsets from
 		 * 8254 offset. */
-		subpriv->clk_sce_iobase =
-		    DIO200_XCLK_SCE + (offset >> 3) + iobase;
-		subpriv->gat_sce_iobase =
-		    DIO200_XGAT_SCE + (offset >> 3) + iobase;
+		subpriv->clk_sce_ofs = DIO200_XCLK_SCE + (offset >> 3);
+		subpriv->gat_sce_ofs = DIO200_XGAT_SCE + (offset >> 3);
 		subpriv->which = (offset >> 2) & 1;
 	}
 
 	/* Initialize channels. */
 	for (chan = 0; chan < 3; chan++) {
-		i8254_set_mode(subpriv->iobase, 0, chan,
+		i8254_set_mode(dev->iobase + subpriv->ofs, 0, chan,
 			       I8254_MODE0 | I8254_BINARY);
 		if (layout->has_clk_gat_sce) {
 			/* Gate source 0 is VCC (logic 1). */
@@ -1228,7 +1227,7 @@ static int dio200_common_attach(struct comedi_device *dev, unsigned long iobase,
 		switch (layout->sdtype[n]) {
 		case sd_8254:
 			/* counter subdevice (8254) */
-			ret = dio200_subdev_8254_init(dev, s, iobase,
+			ret = dio200_subdev_8254_init(dev, s,
 						      layout->sdinfo[n]);
 			if (ret < 0)
 				return ret;
@@ -1244,11 +1243,9 @@ static int dio200_common_attach(struct comedi_device *dev, unsigned long iobase,
 			/* 'INTERRUPT' subdevice */
 			if (irq) {
 				ret = dio200_subdev_intr_init(dev, s,
-							      iobase +
 							      DIO200_INT_SCE,
-							      layout->sdinfo[n],
-							      layout->
-							      has_int_sce);
+							      layout->sdinfo[n]
+							     );
 				if (ret < 0)
 					return ret;
 				devpriv->intr_sd = n;