diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig
index 593fcb1..a2577ba 100644
--- a/drivers/staging/comedi/Kconfig
+++ b/drivers/staging/comedi/Kconfig
@@ -1222,6 +1222,9 @@
 
 endif # COMEDI_USB_DRIVERS
 
+config COMEDI_8254
+	tristate
+
 config COMEDI_8255
 	tristate "Generic 8255 support"
 	---help---
diff --git a/drivers/staging/comedi/drivers/Makefile b/drivers/staging/comedi/drivers/Makefile
index 7d1fbd5..d6d8340 100644
--- a/drivers/staging/comedi/drivers/Makefile
+++ b/drivers/staging/comedi/drivers/Makefile
@@ -3,6 +3,7 @@
 ccflags-$(CONFIG_COMEDI_DEBUG)		:= -DDEBUG
 
 # Comedi "helper" modules
+obj-$(CONFIG_COMEDI_8254)		+= comedi_8254.o
 obj-$(CONFIG_COMEDI_ISADMA)		+= comedi_isadma.o
 
 # Comedi misc drivers
diff --git a/drivers/staging/comedi/drivers/comedi_8254.c b/drivers/staging/comedi/drivers/comedi_8254.c
new file mode 100644
index 0000000..0d5d56b
--- /dev/null
+++ b/drivers/staging/comedi/drivers/comedi_8254.c
@@ -0,0 +1,664 @@
+/*
+ * comedi_8254.c
+ * Generic 8254 timer/counter support
+ * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * Based on 8253.h and various subdevice implementations in comedi drivers.
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Module: comedi_8254
+ * Description: Generic 8254 timer/counter support
+ * Author: H Hartley Sweeten <hsweeten@visionengravers.com>
+ * Updated: Thu Jan 8 16:45:45 MST 2015
+ * Status: works
+ *
+ * This module is not used directly by end-users. Rather, it is used by other
+ * drivers to provide support for an 8254 Programmable Interval Timer. These
+ * counters are typically used to generate the pacer clock used for data
+ * acquisition. Some drivers also expose the counters for general purpose use.
+ *
+ * This module provides the following basic functions:
+ *
+ * comedi_8254_init() / comedi_8254_mm_init()
+ *	Initializes this module to access the 8254 registers. The _mm version
+ *	sets up the module for MMIO register access the other for PIO access.
+ *	The pointer returned from these functions is normally stored in the
+ *	comedi_device dev->pacer and will be freed by the comedi core during
+ *	the driver (*detach). If a driver has multiple 8254 devices, they need
+ *	to be stored in the drivers private data and freed when the driver is
+ *	detached.
+ *
+ *	NOTE: The counters are reset by setting them to I8254_MODE0 as part of
+ *	this initialization.
+ *
+ * comedi_8254_set_mode()
+ *	Sets a counters operation mode:
+ *		I8254_MODE0	Interrupt on terminal count
+ *		I8254_MODE1	Hardware retriggerable one-shot
+ *		I8254_MODE2	Rate generator
+ *		I8254_MODE3	Square wave mode
+ *		I8254_MODE4	Software triggered strobe
+ *		I8254_MODE5	Hardware triggered strobe (retriggerable)
+ *
+ *	In addition I8254_BCD and I8254_BINARY specify the counting mode:
+ *		I8254_BCD	BCD counting
+ *		I8254_BINARY	Binary counting
+ *
+ * comedi_8254_write()
+ *	Writes an initial value to a counter.
+ *
+ *	The largest possible initial count is 0; this is equivalent to 2^16
+ *	for binary counting and 10^4 for BCD counting.
+ *
+ *	NOTE: The counter does not stop when it reaches zero. In Mode 0, 1, 4,
+ *	and 5 the counter "wraps around" to the highest count, either 0xffff
+ *	for binary counting or 9999 for BCD counting, and continues counting.
+ *	Modes 2 and 3 are periodic; the counter reloads itself with the initial
+ *	count and continues counting from there.
+ *
+ * comedi_8254_read()
+ *	Reads the current value from a counter.
+ *
+ * comedi_8254_status()
+ *	Reads the status of a counter.
+ *
+ * comedi_8254_load()
+ *	Sets a counters operation mode and writes the initial value.
+ *
+ * Typically the pacer clock is created by cascading two of the 16-bit counters
+ * to create a 32-bit rate generator (I8254_MODE2). These functions are
+ * provided to handle the cascaded counters:
+ *
+ * comedi_8254_ns_to_timer()
+ *	Calculates the divisor value needed for a single counter to generate
+ *	ns timing.
+ *
+ * comedi_8254_cascade_ns_to_timer()
+ *	Calculates the two divisor values needed to the generate the pacer
+ *	clock (in ns).
+ *
+ * comedi_8254_update_divisors()
+ *	Transfers the intermediate divisor values to the current divisors.
+ *
+ * comedi_8254_pacer_enable()
+ *	Programs the mode of the cascaded counters and writes the current
+ *	divisor values.
+ *
+ * To expose the counters as a subdevice for general purpose use the following
+ * functions a provided:
+ *
+ * comedi_8254_subdevice_init()
+ *	Initializes a comedi_subdevice to use the 8254 timer.
+ *
+ * comedi_8254_set_busy()
+ *	Internally flags a counter as "busy". This is done to protect the
+ *	counters that are used for the cascaded 32-bit pacer.
+ *
+ * The subdevice provides (*insn_read) and (*insn_write) operations to read
+ * the current value and write an initial value to a counter. A (*insn_config)
+ * operation is also provided to handle the following comedi instructions:
+ *
+ *	INSN_CONFIG_SET_COUNTER_MODE	calls comedi_8254_set_mode()
+ *	INSN_CONFIG_8254_READ_STATUS	calls comedi_8254_status()
+ *
+ * The (*insn_config) member of comedi_8254 can be initialized by the external
+ * driver to handle any additional instructions.
+ *
+ * NOTE: Gate control, clock routing, and any interrupt handling for the
+ * counters is not handled by this module. These features are driver dependent.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "../comedidev.h"
+
+#include "comedi_8254.h"
+
+static unsigned int __i8254_read(struct comedi_8254 *i8254, unsigned int reg)
+{
+	unsigned int reg_offset = (reg * i8254->iosize) << i8254->regshift;
+	unsigned int val;
+
+	switch (i8254->iosize) {
+	default:
+	case I8254_IO8:
+		if (i8254->mmio)
+			val = readb(i8254->mmio + reg_offset);
+		else
+			val = inb(i8254->iobase + reg_offset);
+		break;
+	case I8254_IO16:
+		if (i8254->mmio)
+			val = readw(i8254->mmio + reg_offset);
+		else
+			val = inw(i8254->iobase + reg_offset);
+		break;
+	case I8254_IO32:
+		if (i8254->mmio)
+			val = readl(i8254->mmio + reg_offset);
+		else
+			val = inl(i8254->iobase + reg_offset);
+		break;
+	}
+	return val & 0xff;
+}
+
+static void __i8254_write(struct comedi_8254 *i8254,
+			  unsigned int val, unsigned int reg)
+{
+	unsigned int reg_offset = (reg * i8254->iosize) << i8254->regshift;
+
+	switch (i8254->iosize) {
+	default:
+	case I8254_IO8:
+		if (i8254->mmio)
+			writeb(val, i8254->mmio + reg_offset);
+		else
+			outb(val, i8254->iobase + reg_offset);
+		break;
+	case I8254_IO16:
+		if (i8254->mmio)
+			writew(val, i8254->mmio + reg_offset);
+		else
+			outw(val, i8254->iobase + reg_offset);
+		break;
+	case I8254_IO32:
+		if (i8254->mmio)
+			writel(val, i8254->mmio + reg_offset);
+		else
+			outl(val, i8254->iobase + reg_offset);
+		break;
+	}
+}
+
+/**
+ * comedi_8254_status - return the status of a counter
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ */
+unsigned int comedi_8254_status(struct comedi_8254 *i8254, unsigned int counter)
+{
+	unsigned int cmd;
+
+	if (counter > 2)
+		return 0;
+
+	cmd = I8254_CTRL_READBACK_STATUS | I8254_CTRL_READBACK_SEL_CTR(counter);
+	__i8254_write(i8254, cmd, I8254_CTRL_REG);
+
+	return __i8254_read(i8254, counter);
+}
+EXPORT_SYMBOL_GPL(comedi_8254_status);
+
+/**
+ * comedi_8254_read - read the current counter value
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ */
+unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter)
+{
+	unsigned int val;
+
+	if (counter > 2)
+		return 0;
+
+	/* latch counter */
+	__i8254_write(i8254, I8254_CTRL_SEL_CTR(counter) | I8254_CTRL_LATCH,
+		      I8254_CTRL_REG);
+
+	/* read LSB then MSB */
+	val = __i8254_read(i8254, counter);
+	val |= (__i8254_read(i8254, counter) << 8);
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_read);
+
+/**
+ * comedi_8254_write - load a 16-bit initial counter value
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ * @val:	the initial value
+ */
+void comedi_8254_write(struct comedi_8254 *i8254,
+		       unsigned int counter, unsigned int val)
+{
+	unsigned int byte;
+
+	if (counter > 2)
+		return;
+	if (val > 0xffff)
+		return;
+
+	/* load LSB then MSB */
+	byte = val & 0xff;
+	__i8254_write(i8254, byte, counter);
+	byte = (val >> 8) & 0xff;
+	__i8254_write(i8254, byte, counter);
+}
+EXPORT_SYMBOL_GPL(comedi_8254_write);
+
+/**
+ * comedi_8254_set_mode - set the mode of a counter
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ * @mode:	the I8254_MODEx and I8254_BCD|I8254_BINARY
+ */
+int comedi_8254_set_mode(struct comedi_8254 *i8254, unsigned int counter,
+			 unsigned int mode)
+{
+	unsigned int byte;
+
+	if (counter > 2)
+		return -EINVAL;
+	if (mode > (I8254_MODE5 | I8254_BCD))
+		return -EINVAL;
+
+	byte = I8254_CTRL_SEL_CTR(counter) |	/* select counter */
+	       I8254_CTRL_LSB_MSB |		/* load LSB then MSB */
+	       mode;				/* mode and BCD|binary */
+	__i8254_write(i8254, byte, I8254_CTRL_REG);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_set_mode);
+
+/**
+ * comedi_8254_load - program the mode and initial count of a counter
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ * @mode:	the I8254_MODEx and I8254_BCD|I8254_BINARY
+ * @val:	the initial value
+ */
+int comedi_8254_load(struct comedi_8254 *i8254, unsigned int counter,
+		     unsigned int val, unsigned int mode)
+{
+	if (counter > 2)
+		return -EINVAL;
+	if (val > 0xffff)
+		return -EINVAL;
+	if (mode > (I8254_MODE5 | I8254_BCD))
+		return -EINVAL;
+
+	comedi_8254_set_mode(i8254, counter, mode);
+	comedi_8254_write(i8254, counter, val);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_load);
+
+/**
+ * comedi_8254_pacer_enable - set the mode and load the cascaded counters
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter1:	the counter number for the first divisor
+ * @counter2:	the counter number for the second divisor
+ * @enable:	flag to enable (load) the counters
+ */
+void comedi_8254_pacer_enable(struct comedi_8254 *i8254,
+			      unsigned int counter1,
+			      unsigned int counter2,
+			      bool enable)
+{
+	unsigned int mode;
+
+	if (counter1 > 2 || counter2 > 2 || counter1 == counter2)
+		return;
+
+	if (enable)
+		mode = I8254_MODE2 | I8254_BINARY;
+	else
+		mode = I8254_MODE0 | I8254_BINARY;
+
+	comedi_8254_set_mode(i8254, counter1, mode);
+	comedi_8254_set_mode(i8254, counter2, mode);
+
+	if (enable) {
+		/*
+		 * Divisors are loaded second counter then first counter to
+		 * avoid possible issues with the first counter expiring
+		 * before the second counter is loaded.
+		 */
+		comedi_8254_write(i8254, counter2, i8254->divisor2);
+		comedi_8254_write(i8254, counter1, i8254->divisor1);
+	}
+}
+EXPORT_SYMBOL_GPL(comedi_8254_pacer_enable);
+
+/**
+ * comedi_8254_update_divisors - update the divisors for the cascaded counters
+ * @i8254:	comedi_8254 struct for the timer
+ */
+void comedi_8254_update_divisors(struct comedi_8254 *i8254)
+{
+	/* masking is done since counter maps zero to 0x10000 */
+	i8254->divisor = i8254->next_div & 0xffff;
+	i8254->divisor1 = i8254->next_div1 & 0xffff;
+	i8254->divisor2 = i8254->next_div2 & 0xffff;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_update_divisors);
+
+/**
+ * comedi_8254_cascade_ns_to_timer - calculate the cascaded divisor values
+ * @i8254:	comedi_8254 struct for the timer
+ * @nanosec:	the desired ns time
+ * @flags:	comedi_cmd flags
+ */
+void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254,
+				     unsigned int *nanosec,
+				     unsigned int flags)
+{
+	unsigned int d1 = i8254->next_div1 ? i8254->next_div1 : I8254_MAX_COUNT;
+	unsigned int d2 = i8254->next_div2 ? i8254->next_div2 : I8254_MAX_COUNT;
+	unsigned int div = d1 * d2;
+	unsigned int ns_lub = 0xffffffff;
+	unsigned int ns_glb = 0;
+	unsigned int d1_lub = 0;
+	unsigned int d1_glb = 0;
+	unsigned int d2_lub = 0;
+	unsigned int d2_glb = 0;
+	unsigned int start;
+	unsigned int ns;
+	unsigned int ns_low;
+	unsigned int ns_high;
+
+	/* exit early if everything is already correct */
+	if (div * i8254->osc_base == *nanosec &&
+	    d1 > 1 && d1 <= I8254_MAX_COUNT &&
+	    d2 > 1 && d2 <= I8254_MAX_COUNT &&
+	    /* check for overflow */
+	    div > d1 && div > d2 &&
+	    div * i8254->osc_base > div &&
+	    div * i8254->osc_base > i8254->osc_base)
+		return;
+
+	div = *nanosec / i8254->osc_base;
+	d2 = I8254_MAX_COUNT;
+	start = div / d2;
+	if (start < 2)
+		start = 2;
+	for (d1 = start; d1 <= div / d1 + 1 && d1 <= I8254_MAX_COUNT; d1++) {
+		for (d2 = div / d1;
+		     d1 * d2 <= div + d1 + 1 && d2 <= I8254_MAX_COUNT; d2++) {
+			ns = i8254->osc_base * d1 * d2;
+			if (ns <= *nanosec && ns > ns_glb) {
+				ns_glb = ns;
+				d1_glb = d1;
+				d2_glb = d2;
+			}
+			if (ns >= *nanosec && ns < ns_lub) {
+				ns_lub = ns;
+				d1_lub = d1;
+				d2_lub = d2;
+			}
+		}
+	}
+
+	switch (flags & CMDF_ROUND_MASK) {
+	case CMDF_ROUND_NEAREST:
+	default:
+		ns_high = d1_lub * d2_lub * i8254->osc_base;
+		ns_low = d1_glb * d2_glb * i8254->osc_base;
+		if (ns_high - *nanosec < *nanosec - ns_low) {
+			d1 = d1_lub;
+			d2 = d2_lub;
+		} else {
+			d1 = d1_glb;
+			d2 = d2_glb;
+		}
+		break;
+	case CMDF_ROUND_UP:
+		d1 = d1_lub;
+		d2 = d2_lub;
+		break;
+	case CMDF_ROUND_DOWN:
+		d1 = d1_glb;
+		d2 = d2_glb;
+		break;
+	}
+
+	*nanosec = d1 * d2 * i8254->osc_base;
+	i8254->next_div1 = d1;
+	i8254->next_div2 = d2;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_cascade_ns_to_timer);
+
+/**
+ * comedi_8254_ns_to_timer - calculate the divisor value for nanosec timing
+ * @i8254:	comedi_8254 struct for the timer
+ * @nanosec:	the desired ns time
+ * @flags:	comedi_cmd flags
+ */
+void comedi_8254_ns_to_timer(struct comedi_8254 *i8254,
+			     unsigned int *nanosec, unsigned int flags)
+{
+	unsigned int divisor;
+
+	switch (flags & CMDF_ROUND_MASK) {
+	default:
+	case CMDF_ROUND_NEAREST:
+		divisor = DIV_ROUND_CLOSEST(*nanosec, i8254->osc_base);
+		break;
+	case CMDF_ROUND_UP:
+		divisor = DIV_ROUND_UP(*nanosec, i8254->osc_base);
+		break;
+	case CMDF_ROUND_DOWN:
+		divisor = *nanosec / i8254->osc_base;
+		break;
+	}
+	if (divisor < 2)
+		divisor = 2;
+	if (divisor > I8254_MAX_COUNT)
+		divisor = I8254_MAX_COUNT;
+
+	*nanosec = divisor * i8254->osc_base;
+	i8254->next_div = divisor;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_ns_to_timer);
+
+/**
+ * comedi_8254_set_busy - set/clear the "busy" flag for a given counter
+ * @i8254:	comedi_8254 struct for the timer
+ * @counter:	the counter number
+ * @busy:	set/clear flag
+ */
+void comedi_8254_set_busy(struct comedi_8254 *i8254,
+			  unsigned int counter, bool busy)
+{
+	if (counter < 3)
+		i8254->busy[counter] = busy;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_set_busy);
+
+static int comedi_8254_insn_read(struct comedi_device *dev,
+				 struct comedi_subdevice *s,
+				 struct comedi_insn *insn,
+				 unsigned int *data)
+{
+	struct comedi_8254 *i8254 = s->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	int i;
+
+	if (i8254->busy[chan])
+		return -EBUSY;
+
+	for (i = 0; i < insn->n; i++)
+		data[i] = comedi_8254_read(i8254, chan);
+
+	return insn->n;
+}
+
+static int comedi_8254_insn_write(struct comedi_device *dev,
+				  struct comedi_subdevice *s,
+				  struct comedi_insn *insn,
+				  unsigned int *data)
+{
+	struct comedi_8254 *i8254 = s->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+
+	if (i8254->busy[chan])
+		return -EBUSY;
+
+	if (insn->n)
+		comedi_8254_write(i8254, chan, data[insn->n - 1]);
+
+	return insn->n;
+}
+
+static int comedi_8254_insn_config(struct comedi_device *dev,
+				   struct comedi_subdevice *s,
+				   struct comedi_insn *insn,
+				   unsigned int *data)
+{
+	struct comedi_8254 *i8254 = s->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	int ret;
+
+	if (i8254->busy[chan])
+		return -EBUSY;
+
+	switch (data[0]) {
+	case INSN_CONFIG_RESET:
+		ret = comedi_8254_set_mode(i8254, chan,
+					   I8254_MODE0 | I8254_BINARY);
+		if (ret)
+			return ret;
+		break;
+	case INSN_CONFIG_SET_COUNTER_MODE:
+		ret = comedi_8254_set_mode(i8254, chan, data[1]);
+		if (ret)
+			return ret;
+		break;
+	case INSN_CONFIG_8254_READ_STATUS:
+		data[1] = comedi_8254_status(i8254, chan);
+		break;
+	default:
+		/*
+		 * If available, call the driver provided (*insn_config)
+		 * to handle any driver implemented instructions.
+		 */
+		if (i8254->insn_config)
+			return i8254->insn_config(dev, s, insn, data);
+
+		return -EINVAL;
+	}
+
+	return insn->n;
+}
+
+/**
+ * comedi_8254_subdevice_init - initialize a comedi_subdevice for the 8254 timer
+ * @s:		comedi_subdevice struct
+ */
+void comedi_8254_subdevice_init(struct comedi_subdevice *s,
+				struct comedi_8254 *i8254)
+{
+	s->type		= COMEDI_SUBD_COUNTER;
+	s->subdev_flags	= SDF_READABLE | SDF_WRITABLE;
+	s->n_chan	= 3;
+	s->maxdata	= 0xffff;
+	s->range_table	= &range_unknown;
+	s->insn_read	= comedi_8254_insn_read;
+	s->insn_write	= comedi_8254_insn_write;
+	s->insn_config	= comedi_8254_insn_config;
+
+	s->private	= i8254;
+}
+EXPORT_SYMBOL_GPL(comedi_8254_subdevice_init);
+
+static struct comedi_8254 *__i8254_init(unsigned long iobase,
+					void __iomem *mmio,
+					unsigned int osc_base,
+					unsigned int iosize,
+					unsigned int regshift)
+{
+	struct comedi_8254 *i8254;
+	int i;
+
+	/* sanity check that the iosize is valid */
+	if (!(iosize == I8254_IO8 || iosize == I8254_IO16 ||
+	      iosize == I8254_IO32))
+		return NULL;
+
+	i8254 = kzalloc(sizeof(*i8254), GFP_KERNEL);
+	if (!i8254)
+		return NULL;
+
+	i8254->iobase	= iobase;
+	i8254->mmio	= mmio;
+	i8254->iosize	= iosize;
+	i8254->regshift	= regshift;
+
+	/* default osc_base to the max speed of a generic 8254 timer */
+	i8254->osc_base	= osc_base ? osc_base : I8254_OSC_BASE_10MHZ;
+
+	/* reset all the counters by setting them to I8254_MODE0 */
+	for (i = 0; i < 3; i++)
+		comedi_8254_set_mode(i8254, i, I8254_MODE0 | I8254_BINARY);
+
+	return i8254;
+}
+
+/**
+ * comedi_8254_init - allocate and initialize the 8254 device for pio access
+ * @mmio:	port I/O base address
+ * @osc_base:	base time of the counter in ns
+ *		OPTIONAL - only used by comedi_8254_cascade_ns_to_timer()
+ * @iosize:	I/O register size
+ * @regshift:	register gap shift
+ */
+struct comedi_8254 *comedi_8254_init(unsigned long iobase,
+				     unsigned int osc_base,
+				     unsigned int iosize,
+				     unsigned int regshift)
+{
+	return __i8254_init(iobase, NULL, osc_base, iosize, regshift);
+}
+EXPORT_SYMBOL_GPL(comedi_8254_init);
+
+/**
+ * comedi_8254_mm_init - allocate and initialize the 8254 device for mmio access
+ * @mmio:	memory mapped I/O base address
+ * @osc_base:	base time of the counter in ns
+ *		OPTIONAL - only used by comedi_8254_cascade_ns_to_timer()
+ * @iosize:	I/O register size
+ * @regshift:	register gap shift
+ */
+struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio,
+					unsigned int osc_base,
+					unsigned int iosize,
+					unsigned int regshift)
+{
+	return __i8254_init(0, mmio, osc_base, iosize, regshift);
+}
+EXPORT_SYMBOL_GPL(comedi_8254_mm_init);
+
+static int __init comedi_8254_module_init(void)
+{
+	return 0;
+}
+module_init(comedi_8254_module_init);
+
+static void __exit comedi_8254_module_exit(void)
+{
+}
+module_exit(comedi_8254_module_exit);
+
+MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
+MODULE_DESCRIPTION("Comedi: Generic 8254 timer/counter support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/comedi/drivers/comedi_8254.h b/drivers/staging/comedi/drivers/comedi_8254.h
new file mode 100644
index 0000000..54f2bf8
--- /dev/null
+++ b/drivers/staging/comedi/drivers/comedi_8254.h
@@ -0,0 +1,129 @@
+/*
+ * comedi_8254.h
+ * Generic 8254 timer/counter support
+ * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _COMEDI_8254_H
+#define _COMEDI_8254_H
+
+/*
+ * Common oscillator base values in nanoseconds
+ */
+#define I8254_OSC_BASE_10MHZ	100
+#define I8254_OSC_BASE_5MHZ	200
+#define I8254_OSC_BASE_4MHZ	250
+#define I8254_OSC_BASE_2MHZ	500
+#define I8254_OSC_BASE_1MHZ	1000
+#define I8254_OSC_BASE_100KHZ	10000
+#define I8254_OSC_BASE_10KHZ	100000
+#define I8254_OSC_BASE_1KHZ	1000000
+
+/*
+ * I/O access size used to read/write registers
+ */
+#define I8254_IO8		1
+#define I8254_IO16		2
+#define I8254_IO32		4
+
+/*
+ * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)
+ */
+#define I8254_COUNTER0_REG		0x00
+#define I8254_COUNTER1_REG		0x01
+#define I8254_COUNTER2_REG		0x02
+#define I8254_CTRL_REG			0x03
+#define I8254_CTRL_SEL_CTR(x)		((x) << 6)
+#define I8254_CTRL_READBACK_COUNT	((3 << 6) | (1 << 4))
+#define I8254_CTRL_READBACK_STATUS	((3 << 6) | (1 << 5))
+#define I8254_CTRL_READBACK_SEL_CTR(x)	(2 << (x))
+#define I8254_CTRL_LATCH		(0 << 4)
+#define I8254_CTRL_LSB_ONLY		(1 << 4)
+#define I8254_CTRL_MSB_ONLY		(2 << 4)
+#define I8254_CTRL_LSB_MSB		(3 << 4)
+
+/* counter maps zero to 0x10000 */
+#define I8254_MAX_COUNT			0x10000
+
+/**
+ * struct comedi_8254 - private data used by this module
+ * @iobase:		PIO base address of the registers (in/out)
+ * @mmio:		MMIO base address of the registers (read/write)
+ * @iosize:		I/O size used to access the registers (b/w/l)
+ * @regshift:		register gap shift
+ * @osc_base:		cascaded oscillator speed in ns
+ * @divisor:		divisor for single counter
+ * @divisor1:		divisor loaded into first cascaded counter
+ * @divisor2:		divisor loaded into second cascaded counter
+ * #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
+ * @busy:		flags used to indicate that a counter is "busy"
+ * @insn_config:	driver specific (*insn_config) callback
+ */
+struct comedi_8254 {
+	unsigned long iobase;
+	void __iomem *mmio;
+	unsigned int iosize;
+	unsigned int regshift;
+	unsigned int osc_base;
+	unsigned int divisor;
+	unsigned int divisor1;
+	unsigned int divisor2;
+	unsigned int next_div;
+	unsigned int next_div1;
+	unsigned int next_div2;
+	bool busy[3];
+
+	int (*insn_config)(struct comedi_device *, struct comedi_subdevice *s,
+			   struct comedi_insn *, unsigned int *data);
+};
+
+unsigned int comedi_8254_status(struct comedi_8254 *, unsigned int counter);
+unsigned int comedi_8254_read(struct comedi_8254 *, unsigned int counter);
+void comedi_8254_write(struct comedi_8254 *,
+		       unsigned int counter, unsigned int val);
+
+int comedi_8254_set_mode(struct comedi_8254 *,
+			 unsigned int counter, unsigned int mode);
+int comedi_8254_load(struct comedi_8254 *,
+		     unsigned int counter, unsigned int val, unsigned int mode);
+
+void comedi_8254_pacer_enable(struct comedi_8254 *,
+			      unsigned int counter1, unsigned int counter2,
+			      bool enable);
+void comedi_8254_update_divisors(struct comedi_8254 *);
+void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *,
+				     unsigned int *nanosec, unsigned int flags);
+void comedi_8254_ns_to_timer(struct comedi_8254 *,
+			     unsigned int *nanosec, unsigned int flags);
+
+void comedi_8254_set_busy(struct comedi_8254 *,
+			  unsigned int counter, bool busy);
+
+void comedi_8254_subdevice_init(struct comedi_subdevice *,
+				struct comedi_8254 *);
+
+struct comedi_8254 *comedi_8254_init(unsigned long iobase,
+				     unsigned int osc_base,
+				     unsigned int iosize,
+				     unsigned int regshift);
+struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio,
+					unsigned int osc_base,
+					unsigned int iosize,
+					unsigned int regshift);
+
+#endif	/* _COMEDI_8254_H */