staging: comedi: amplc_dio200_common: convert driver to use the comedi_8254 module

Convert this driver to use the comedi_8254 module to provide the 8254 timer support.

Add 'clock_src' and 'gate_src' members to the comedi_8254 data for convienence.
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

@@ -1275,6 +1275,7 @@ config COMEDI_KCOMEDILIB
 	  called kcomedilib.
 
 config COMEDI_AMPLC_DIO200
+	select COMEDI_8254
 	tristate
 
 config COMEDI_AMPLC_PC236

drivers/staging/comedi/drivers/amplc_dio200_common.c

@@ -26,7 +26,7 @@
 
 #include "amplc_dio200.h"
 #include "comedi_fc.h"
-#include "8253.h"
+#include "comedi_8254.h"
 #include "8255.h"		/* only for register defines */
 
 /* 200 series registers */
@@ -97,12 +97,6 @@ static const unsigned int ts_clock_period[TS_CONFIG_MAX_CLK_SRC + 1] = {
 	1000000,		/* 1 millisecond. */
 };
 
-struct dio200_subdev_8254 {
-	unsigned int ofs;		/* Counter base offset */
-	unsigned int clock_src[3];	/* Current clock sources */
-	unsigned int gate_src[3];	/* Current gate sources */
-};
-
 struct dio200_subdev_8255 {
 	unsigned int ofs;		/* DIO base offset */
 };
@@ -169,6 +163,27 @@ static void dio200_write32(struct comedi_device *dev,
 		outl(val, dev->iobase + offset);
 }
 
+static unsigned int dio200_subdev_8254_offset(struct comedi_device *dev,
+					      struct comedi_subdevice *s)
+{
+	const struct dio200_board *board = dev->board_ptr;
+	struct comedi_8254 *i8254 = s->private;
+	unsigned int offset;
+
+	/* get the offset that was passed to comedi_8254_*_init() */
+	if (dev->mmio)
+		offset = i8254->mmio - dev->mmio;
+	else
+		offset = i8254->iobase - dev->iobase;
+
+	/* remove the shift that was added for PCIe boards */
+	if (board->is_pcie)
+		offset >>= 3;
+
+	/* this offset now works for the dio200_{read,write} helpers */
+	return offset;
+}
+
 static int dio200_subdev_intr_insn_bits(struct comedi_device *dev,
 					struct comedi_subdevice *s,
 					struct comedi_insn *insn,
@@ -474,211 +489,71 @@ static irqreturn_t dio200_interrupt(int irq, void *d)
 	return IRQ_RETVAL(handled);
 }
 
-static unsigned int dio200_subdev_8254_read_chan(struct comedi_device *dev,
-						 struct comedi_subdevice *s,
-						 unsigned int chan)
-{
-	struct dio200_subdev_8254 *subpriv = s->private;
-	unsigned int val;
-
-	/* latch counter */
-	val = chan << 6;
-	dio200_write8(dev, subpriv->ofs + i8254_control_reg, val);
-	/* read lsb, msb */
-	val = dio200_read8(dev, subpriv->ofs + chan);
-	val += dio200_read8(dev, subpriv->ofs + chan) << 8;
-	return val;
-}
-
-static void dio200_subdev_8254_write_chan(struct comedi_device *dev,
+static void dio200_subdev_8254_set_gate_src(struct comedi_device *dev,
 					    struct comedi_subdevice *s,
 					    unsigned int chan,
-					  unsigned int count)
+					    unsigned int src)
 {
-	struct dio200_subdev_8254 *subpriv = s->private;
+	unsigned int offset = dio200_subdev_8254_offset(dev, s);
 
-	/* write lsb, msb */
-	dio200_write8(dev, subpriv->ofs + chan, count & 0xff);
-	dio200_write8(dev, subpriv->ofs + chan, (count >> 8) & 0xff);
+	dio200_write8(dev, DIO200_GAT_SCE(offset >> 3),
+		      gat_sce((offset >> 2) & 1, chan, src));
 }
 
-static void dio200_subdev_8254_set_mode(struct comedi_device *dev,
+static void dio200_subdev_8254_set_clock_src(struct comedi_device *dev,
 					     struct comedi_subdevice *s,
 					     unsigned int chan,
-					unsigned int mode)
-{
-	struct dio200_subdev_8254 *subpriv = s->private;
-	unsigned int byte;
-
-	byte = chan << 6;
-	byte |= 0x30;		/* access order: lsb, msb */
-	byte |= (mode & 0xf);	/* counter mode and BCD|binary */
-	dio200_write8(dev, subpriv->ofs + i8254_control_reg, byte);
-}
-
-static unsigned int dio200_subdev_8254_status(struct comedi_device *dev,
-					      struct comedi_subdevice *s,
-					      unsigned int chan)
-{
-	struct dio200_subdev_8254 *subpriv = s->private;
-
-	/* latch status */
-	dio200_write8(dev, subpriv->ofs + i8254_control_reg,
-		      0xe0 | (2 << chan));
-	/* read status */
-	return dio200_read8(dev, subpriv->ofs + chan);
-}
-
-static int dio200_subdev_8254_read(struct comedi_device *dev,
-				   struct comedi_subdevice *s,
-				   struct comedi_insn *insn,
-				   unsigned int *data)
+					     unsigned int src)
 {
-	int chan = CR_CHAN(insn->chanspec);
-	unsigned int n;
-
-	for (n = 0; n < insn->n; n++)
-		data[n] = dio200_subdev_8254_read_chan(dev, s, chan);
+	unsigned int offset = dio200_subdev_8254_offset(dev, s);
 
-	return insn->n;
+	dio200_write8(dev, DIO200_CLK_SCE(offset >> 3),
+		      clk_sce((offset >> 2) & 1, chan, src));
 }
 
-static int dio200_subdev_8254_write(struct comedi_device *dev,
+static int dio200_subdev_8254_config(struct comedi_device *dev,
 				     struct comedi_subdevice *s,
 				     struct comedi_insn *insn,
 				     unsigned int *data)
-{
-	int chan = CR_CHAN(insn->chanspec);
-	unsigned int n;
-
-	for (n = 0; n < insn->n; n++)
-		dio200_subdev_8254_write_chan(dev, s, chan, data[n]);
-
-	return insn->n;
-}
-
-static int dio200_subdev_8254_set_gate_src(struct comedi_device *dev,
-					   struct comedi_subdevice *s,
-					   unsigned int counter_number,
-					   unsigned int gate_src)
 {
 	const struct dio200_board *board = dev->board_ptr;
-	struct dio200_subdev_8254 *subpriv = s->private;
-	unsigned char byte;
-
-	if (!board->has_clk_gat_sce)
-		return -1;
-	if (gate_src > (board->is_pcie ? 31 : 7))
-		return -1;
-
-	subpriv->gate_src[counter_number] = gate_src;
-	byte = gat_sce((subpriv->ofs >> 2) & 1, counter_number, gate_src);
-	dio200_write8(dev, DIO200_GAT_SCE(subpriv->ofs >> 3), byte);
-
-	return 0;
-}
-
-static int dio200_subdev_8254_get_gate_src(struct comedi_device *dev,
-					   struct comedi_subdevice *s,
-					   unsigned int counter_number)
-{
-	const struct dio200_board *board = dev->board_ptr;
-	struct dio200_subdev_8254 *subpriv = s->private;
-
-	if (!board->has_clk_gat_sce)
-		return -1;
-
-	return subpriv->gate_src[counter_number];
-}
-
-static int dio200_subdev_8254_set_clock_src(struct comedi_device *dev,
-					    struct comedi_subdevice *s,
-					    unsigned int counter_number,
-					    unsigned int clock_src)
-{
-	const struct dio200_board *board = dev->board_ptr;
-	struct dio200_subdev_8254 *subpriv = s->private;
-	unsigned char byte;
-
-	if (!board->has_clk_gat_sce)
-		return -1;
-	if (clock_src > (board->is_pcie ? 31 : 7))
-		return -1;
-
-	subpriv->clock_src[counter_number] = clock_src;
-	byte = clk_sce((subpriv->ofs >> 2) & 1, counter_number, clock_src);
-	dio200_write8(dev, DIO200_CLK_SCE(subpriv->ofs >> 3), byte);
-
-	return 0;
-}
-
-static int dio200_subdev_8254_get_clock_src(struct comedi_device *dev,
-					    struct comedi_subdevice *s,
-					    unsigned int counter_number,
-					    unsigned int *period_ns)
-{
-	const struct dio200_board *board = dev->board_ptr;
-	struct dio200_subdev_8254 *subpriv = s->private;
-	unsigned clock_src;
+	struct comedi_8254 *i8254 = s->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	unsigned int max_src = board->is_pcie ? 31 : 7;
+	unsigned int src;
 
 	if (!board->has_clk_gat_sce)
-		return -1;
-
-	clock_src = subpriv->clock_src[counter_number];
-	*period_ns = clock_period[clock_src];
-	return clock_src;
-}
-
-static int dio200_subdev_8254_config(struct comedi_device *dev,
-				     struct comedi_subdevice *s,
-				     struct comedi_insn *insn,
-				     unsigned int *data)
-{
-	int ret = 0;
-	int chan = CR_CHAN(insn->chanspec);
+		return -EINVAL;
 
 	switch (data[0]) {
-	case INSN_CONFIG_SET_COUNTER_MODE:
-		if (data[1] > (I8254_MODE5 | I8254_BCD))
-			ret = -EINVAL;
-		else
-			dio200_subdev_8254_set_mode(dev, s, chan, data[1]);
-		break;
-	case INSN_CONFIG_8254_READ_STATUS:
-		data[1] = dio200_subdev_8254_status(dev, s, chan);
-		break;
 	case INSN_CONFIG_SET_GATE_SRC:
-		ret = dio200_subdev_8254_set_gate_src(dev, s, chan, data[2]);
-		if (ret < 0)
-			ret = -EINVAL;
+		src = data[2];
+		if (src > max_src)
+			return -EINVAL;
+
+		dio200_subdev_8254_set_gate_src(dev, s, chan, src);
+		i8254->gate_src[chan] = src;
 		break;
 	case INSN_CONFIG_GET_GATE_SRC:
-		ret = dio200_subdev_8254_get_gate_src(dev, s, chan);
-		if (ret < 0) {
-			ret = -EINVAL;
-			break;
-		}
-		data[2] = ret;
+		data[2] = i8254->gate_src[chan];
 		break;
 	case INSN_CONFIG_SET_CLOCK_SRC:
-		ret = dio200_subdev_8254_set_clock_src(dev, s, chan, data[1]);
-		if (ret < 0)
-			ret = -EINVAL;
+		src = data[1];
+		if (src > max_src)
+			return -EINVAL;
+
+		dio200_subdev_8254_set_clock_src(dev, s, chan, src);
+		i8254->clock_src[chan] = src;
 		break;
 	case INSN_CONFIG_GET_CLOCK_SRC:
-		ret = dio200_subdev_8254_get_clock_src(dev, s, chan, &data[2]);
-		if (ret < 0) {
-			ret = -EINVAL;
-			break;
-		}
-		data[1] = ret;
+		data[1] = i8254->clock_src[chan];
+		data[2] = clock_period[i8254->clock_src[chan]];
 		break;
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
 
-	return ret < 0 ? ret : insn->n;
+	return insn->n;
 }
 
 static int dio200_subdev_8254_init(struct comedi_device *dev,
@@ -686,28 +561,46 @@ static int dio200_subdev_8254_init(struct comedi_device *dev,
 				   unsigned int offset)
 {
 	const struct dio200_board *board = dev->board_ptr;
-	struct dio200_subdev_8254 *subpriv;
-	unsigned int chan;
+	struct comedi_8254 *i8254;
+	unsigned int regshift;
+	int chan;
 
-	subpriv = comedi_alloc_spriv(s, sizeof(*subpriv));
-	if (!subpriv)
+	/*
+	 * PCIe boards need the offset shifted in order to get the
+	 * correct base address of the timer.
+	 */
+	if (board->is_pcie) {
+		offset <<= 3;
+		regshift = 3;
+	} else {
+		regshift = 0;
+	}
+
+	if (dev->mmio)
+		i8254 = comedi_8254_mm_init(dev->mmio + offset,
+					    0, I8254_IO8, regshift);
+	else
+		i8254 = comedi_8254_init(dev->iobase + offset,
+					 0, I8254_IO8, regshift);
+	if (!i8254)
 		return -ENOMEM;
 
-	s->type = COMEDI_SUBD_COUNTER;
-	s->subdev_flags = SDF_WRITABLE | SDF_READABLE;
-	s->n_chan = 3;
-	s->maxdata = 0xFFFF;
-	s->insn_read = dio200_subdev_8254_read;
-	s->insn_write = dio200_subdev_8254_write;
-	s->insn_config = dio200_subdev_8254_config;
+	comedi_8254_subdevice_init(s, i8254);
 
-	subpriv->ofs = offset;
+	i8254->insn_config = dio200_subdev_8254_config;
+
+	/*
+	 * There could be multiple timers so this driver does not
+	 * use dev->pacer to save the i8254 pointer. Instead,
+	 * comedi_8254_subdevice_init() saved the i8254 pointer in
+	 * s->private. Set the runflag bit so that the core will
+	 * automatically free it when the driver is detached.
+	 */
+	s->runflags |= COMEDI_SRF_FREE_SPRIV;
 
 	/* Initialize channels. */
-	for (chan = 0; chan < 3; chan++) {
-		dio200_subdev_8254_set_mode(dev, s, chan,
-					    I8254_MODE0 | I8254_BINARY);
 	if (board->has_clk_gat_sce) {
+		for (chan = 0; chan < 3; chan++) {
 			/* Gate source 0 is VCC (logic 1). */
 			dio200_subdev_8254_set_gate_src(dev, s, chan, 0);
 			/* Clock source 0 is the dedicated clock input. */

drivers/staging/comedi/drivers/comedi_8254.h

@@ -71,6 +71,8 @@
  * #next_div:		next divisor for single counter
  * @next_div1:		next divisor to use for first cascaded counter
  * @next_div2:		next divisor to use for second cascaded counter
+ * @clock_src;		current clock source for each counter (driver specific)
+ * @gate_src;		current gate source  for each counter (driver specific)
  * @busy:		flags used to indicate that a counter is "busy"
  * @insn_config:	driver specific (*insn_config) callback
  */
@@ -86,6 +88,8 @@ struct comedi_8254 {
 	unsigned int next_div;
 	unsigned int next_div1;
 	unsigned int next_div2;
+	unsigned int clock_src[3];
+	unsigned int gate_src[3];
 	bool busy[3];
 
 	int (*insn_config)(struct comedi_device *, struct comedi_subdevice *s,