1 files changed, 219 insertions, 340 deletions

diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 71c0bea34d7b..cf5a50102d49 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -6,20 +6,23 @@
  * This driver supports the following ACCES devices: 104-DIO-48E and
  * 104-DIO-24E.
  */
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
+#include <linux/bits.h>
 #include <linux/device.h>
-#include <linux/errno.h>
-#include <linux/gpio/driver.h>
-#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/i8254.h>
 #include <linux/ioport.h>
-#include <linux/interrupt.h>
-#include <linux/irqdesc.h>
+#include <linux/irq.h>
 #include <linux/isa.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/regmap.h>
 #include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "gpio-i8255.h"
+
+MODULE_IMPORT_NS("I8255");
 
 #define DIO48E_EXTENT 16
 #define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
@@ -30,324 +33,163 @@ module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
 MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
 
 static unsigned int irq[MAX_NUM_DIO48E];
-module_param_hw_array(irq, uint, irq, NULL, 0);
+static unsigned int num_irq;
+module_param_hw_array(irq, uint, irq, &num_irq, 0);
 MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
 
-/**
- * struct dio48e_gpio - GPIO device private data structure
- * @chip:	instance of the gpio_chip
- * @io_state:	bit I/O state (whether bit is set to input or output)
- * @out_state:	output bits state
- * @control:	Control registers state
- * @lock:	synchronization lock to prevent I/O race conditions
- * @base:	base port address of the GPIO device
- * @irq_mask:	I/O bits affected by interrupts
- */
-struct dio48e_gpio {
-	struct gpio_chip chip;
-	unsigned char io_state[6];
-	unsigned char out_state[6];
-	unsigned char control[2];
-	raw_spinlock_t lock;
-	unsigned int base;
-	unsigned char irq_mask;
-};
-
-static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned int port = offset / 8;
-	const unsigned int mask = BIT(offset % 8);
-
-	if (dio48egpio->io_state[port] & mask)
-		return  GPIO_LINE_DIRECTION_IN;
+#define DIO48E_ENABLE_INTERRUPT 0xB
+#define DIO48E_DISABLE_INTERRUPT DIO48E_ENABLE_INTERRUPT
+#define DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING 0xD
+#define DIO48E_DISABLE_COUNTER_TIMER_ADDRESSING DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING
+#define DIO48E_CLEAR_INTERRUPT 0xF
 
-	return GPIO_LINE_DIRECTION_OUT;
-}
+#define DIO48E_NUM_PPI 2
 
-static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned int io_port = offset / 8;
-	const unsigned int control_port = io_port / 3;
-	const unsigned int control_addr = dio48egpio->base + 3 + control_port * 4;
-	unsigned long flags;
-	unsigned int control;
+static const struct regmap_range dio48e_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x9), regmap_reg_range(0xB, 0xB),
+	regmap_reg_range(0xD, 0xD), regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_rd_ranges[] = {
+	regmap_reg_range(0x0, 0x2), regmap_reg_range(0x4, 0x6),
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_volatile_ranges[] = {
+	i8255_volatile_regmap_range(0x0), i8255_volatile_regmap_range(0x4),
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_range dio48e_precious_ranges[] = {
+	regmap_reg_range(0xB, 0xB), regmap_reg_range(0xD, 0xD),
+	regmap_reg_range(0xF, 0xF),
+};
+static const struct regmap_access_table dio48e_wr_table = {
+	.yes_ranges = dio48e_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_wr_ranges),
+};
+static const struct regmap_access_table dio48e_rd_table = {
+	.yes_ranges = dio48e_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_rd_ranges),
+};
+static const struct regmap_access_table dio48e_volatile_table = {
+	.yes_ranges = dio48e_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_volatile_ranges),
+};
+static const struct regmap_access_table dio48e_precious_table = {
+	.yes_ranges = dio48e_precious_ranges,
+	.n_yes_ranges = ARRAY_SIZE(dio48e_precious_ranges),
+};
 
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
+static const struct regmap_range pit_wr_ranges[] = {
+	regmap_reg_range(0x0, 0x3),
+};
+static const struct regmap_range pit_rd_ranges[] = {
+	regmap_reg_range(0x0, 0x2),
+};
+static const struct regmap_access_table pit_wr_table = {
+	.yes_ranges = pit_wr_ranges,
+	.n_yes_ranges = ARRAY_SIZE(pit_wr_ranges),
+};
+static const struct regmap_access_table pit_rd_table = {
+	.yes_ranges = pit_rd_ranges,
+	.n_yes_ranges = ARRAY_SIZE(pit_rd_ranges),
+};
 
-	/* Check if configuring Port C */
-	if (io_port == 2 || io_port == 5) {
-		/* Port C can be configured by nibble */
-		if (offset % 8 > 3) {
-			dio48egpio->io_state[io_port] |= 0xF0;
-			dio48egpio->control[control_port] |= BIT(3);
-		} else {
-			dio48egpio->io_state[io_port] |= 0x0F;
-			dio48egpio->control[control_port] |= BIT(0);
-		}
-	} else {
-		dio48egpio->io_state[io_port] |= 0xFF;
-		if (io_port == 0 || io_port == 3)
-			dio48egpio->control[control_port] |= BIT(4);
-		else
-			dio48egpio->control[control_port] |= BIT(1);
+/* only bit 3 on each respective Port C supports interrupts */
+#define DIO48E_REGMAP_IRQ(_ppi)						\
+	[19 + (_ppi) * 24] = {						\
+		.mask = BIT(_ppi),					\
+		.type = { .types_supported = IRQ_TYPE_EDGE_RISING },	\
 	}
 
-	control = BIT(7) | dio48egpio->control[control_port];
-	outb(control, control_addr);
-	control &= ~BIT(7);
-	outb(control, control_addr);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-
-	return 0;
-}
+static const struct regmap_irq dio48e_regmap_irqs[] = {
+	DIO48E_REGMAP_IRQ(0), DIO48E_REGMAP_IRQ(1),
+};
 
-static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
-					int value)
-{
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned int io_port = offset / 8;
-	const unsigned int control_port = io_port / 3;
-	const unsigned int mask = BIT(offset % 8);
-	const unsigned int control_addr = dio48egpio->base + 3 + control_port * 4;
-	const unsigned int out_port = (io_port > 2) ? io_port + 1 : io_port;
+/**
+ * struct dio48e_gpio - GPIO device private data structure
+ * @lock:	synchronization lock to prevent I/O race conditions
+ * @map:	Regmap for the device
+ * @regs:	virtual mapping for device registers
+ * @flags:	IRQ flags saved during locking
+ * @irq_mask:	Current IRQ mask state on the device
+ */
+struct dio48e_gpio {
+	raw_spinlock_t lock;
+	struct regmap *map;
+	void __iomem *regs;
 	unsigned long flags;
-	unsigned int control;
-
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
-	/* Check if configuring Port C */
-	if (io_port == 2 || io_port == 5) {
-		/* Port C can be configured by nibble */
-		if (offset % 8 > 3) {
-			dio48egpio->io_state[io_port] &= 0x0F;
-			dio48egpio->control[control_port] &= ~BIT(3);
-		} else {
-			dio48egpio->io_state[io_port] &= 0xF0;
-			dio48egpio->control[control_port] &= ~BIT(0);
-		}
-	} else {
-		dio48egpio->io_state[io_port] &= 0x00;
-		if (io_port == 0 || io_port == 3)
-			dio48egpio->control[control_port] &= ~BIT(4);
-		else
-			dio48egpio->control[control_port] &= ~BIT(1);
-	}
-
-	if (value)
-		dio48egpio->out_state[io_port] |= mask;
-	else
-		dio48egpio->out_state[io_port] &= ~mask;
-
-	control = BIT(7) | dio48egpio->control[control_port];
-	outb(control, control_addr);
-
-	outb(dio48egpio->out_state[io_port], dio48egpio->base + out_port);
-
-	control &= ~BIT(7);
-	outb(control, control_addr);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-
-	return 0;
-}
+	unsigned int irq_mask;
+};
 
-static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
+static void dio48e_regmap_lock(void *lock_arg) __acquires(&dio48egpio->lock)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned int port = offset / 8;
-	const unsigned int mask = BIT(offset % 8);
-	const unsigned int in_port = (port > 2) ? port + 1 : port;
+	struct dio48e_gpio *const dio48egpio = lock_arg;
 	unsigned long flags;
-	unsigned int port_state;
 
 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
-	/* ensure that GPIO is set for input */
-	if (!(dio48egpio->io_state[port] & mask)) {
-		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-		return -EINVAL;
-	}
-
-	port_state = inb(dio48egpio->base + in_port);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-
-	return !!(port_state & mask);
+	dio48egpio->flags = flags;
 }
 
-static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
-
-static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
-	unsigned long *bits)
+static void dio48e_regmap_unlock(void *lock_arg) __releases(&dio48egpio->lock)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	unsigned int port_addr;
-	unsigned long port_state;
-
-	/* clear bits array to a clean slate */
-	bitmap_zero(bits, chip->ngpio);
-
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		port_addr = dio48egpio->base + ports[offset / 8];
-		port_state = inb(port_addr) & gpio_mask;
-
-		bitmap_set_value8(bits, port_state, offset);
-	}
+	struct dio48e_gpio *const dio48egpio = lock_arg;
 
-	return 0;
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, dio48egpio->flags);
 }
 
-static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+static void pit_regmap_lock(void *lock_arg) __acquires(&dio48egpio->lock)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned int port = offset / 8;
-	const unsigned int mask = BIT(offset % 8);
-	const unsigned int out_port = (port > 2) ? port + 1 : port;
+	struct dio48e_gpio *const dio48egpio = lock_arg;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
+	dio48egpio->flags = flags;
 
-	if (value)
-		dio48egpio->out_state[port] |= mask;
-	else
-		dio48egpio->out_state[port] &= ~mask;
-
-	outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	iowrite8(0x00, dio48egpio->regs + DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING);
 }
 
-static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
-	unsigned long *mask, unsigned long *bits)
+static void pit_regmap_unlock(void *lock_arg) __releases(&dio48egpio->lock)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	unsigned long offset;
-	unsigned long gpio_mask;
-	size_t index;
-	unsigned int port_addr;
-	unsigned long bitmask;
-	unsigned long flags;
-
-	for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) {
-		index = offset / 8;
-		port_addr = dio48egpio->base + ports[index];
-
-		bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
-
-		raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
-		/* update output state data and set device gpio register */
-		dio48egpio->out_state[index] &= ~gpio_mask;
-		dio48egpio->out_state[index] |= bitmask;
-		outb(dio48egpio->out_state[index], port_addr);
+	struct dio48e_gpio *const dio48egpio = lock_arg;
 
-		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-	}
-}
+	ioread8(dio48egpio->regs + DIO48E_DISABLE_COUNTER_TIMER_ADDRESSING);
 
-static void dio48e_irq_ack(struct irq_data *data)
-{
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, dio48egpio->flags);
 }
 
-static void dio48e_irq_mask(struct irq_data *data)
+static int dio48e_handle_mask_sync(const int index,
+				   const unsigned int mask_buf_def,
+				   const unsigned int mask_buf,
+				   void *const irq_drv_data)
 {
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	unsigned long flags;
-
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return;
-
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
-	if (offset == 19)
-		dio48egpio->irq_mask &= ~BIT(0);
-	else
-		dio48egpio->irq_mask &= ~BIT(1);
-
-	if (!dio48egpio->irq_mask)
-		/* disable interrupts */
-		inb(dio48egpio->base + 0xB);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-}
-
-static void dio48e_irq_unmask(struct irq_data *data)
-{
-	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
-	const unsigned long offset = irqd_to_hwirq(data);
-	unsigned long flags;
+	struct dio48e_gpio *const dio48egpio = irq_drv_data;
+	const unsigned int prev_mask = dio48egpio->irq_mask;
+	int err;
+	unsigned int val;
 
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return;
+	/* exit early if no change since the previous mask */
+	if (mask_buf == prev_mask)
+		return 0;
 
-	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
+	/* remember the current mask for the next mask sync */
+	dio48egpio->irq_mask = mask_buf;
 
-	if (!dio48egpio->irq_mask) {
-		/* enable interrupts */
-		outb(0x00, dio48egpio->base + 0xF);
-		outb(0x00, dio48egpio->base + 0xB);
+	/* if all previously masked, enable interrupts when unmasking */
+	if (prev_mask == mask_buf_def) {
+		err = regmap_write(dio48egpio->map, DIO48E_CLEAR_INTERRUPT, 0x00);
+		if (err)
+			return err;
+		return regmap_write(dio48egpio->map, DIO48E_ENABLE_INTERRUPT, 0x00);
 	}
 
-	if (offset == 19)
-		dio48egpio->irq_mask |= BIT(0);
-	else
-		dio48egpio->irq_mask |= BIT(1);
-
-	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-}
-
-static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
-{
-	const unsigned long offset = irqd_to_hwirq(data);
-
-	/* only bit 3 on each respective Port C supports interrupts */
-	if (offset != 19 && offset != 43)
-		return -EINVAL;
-
-	if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
-		return -EINVAL;
+	/* if all are currently masked, disable interrupts */
+	if (mask_buf == mask_buf_def)
+		return regmap_read(dio48egpio->map, DIO48E_DISABLE_INTERRUPT, &val);
 
 	return 0;
 }
 
-static struct irq_chip dio48e_irqchip = {
-	.name = "104-dio-48e",
-	.irq_ack = dio48e_irq_ack,
-	.irq_mask = dio48e_irq_mask,
-	.irq_unmask = dio48e_irq_unmask,
-	.irq_set_type = dio48e_irq_set_type
-};
-
-static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
-{
-	struct dio48e_gpio *const dio48egpio = dev_id;
-	struct gpio_chip *const chip = &dio48egpio->chip;
-	const unsigned long irq_mask = dio48egpio->irq_mask;
-	unsigned long gpio;
-
-	for_each_set_bit(gpio, &irq_mask, 2)
-		generic_handle_irq(irq_find_mapping(chip->irq.domain,
-			19 + gpio*24));
-
-	raw_spin_lock(&dio48egpio->lock);
-
-	outb(0x00, dio48egpio->base + 0xF);
-
-	raw_spin_unlock(&dio48egpio->lock);
-
-	return IRQ_HANDLED;
-}
-
 #define DIO48E_NGPIO 48
 static const char *dio48e_names[DIO48E_NGPIO] = {
 	"PPI Group 0 Port A 0", "PPI Group 0 Port A 1", "PPI Group 0 Port A 2",
@@ -368,26 +210,27 @@ static const char *dio48e_names[DIO48E_NGPIO] = {
 	"PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
 };
 
-static int dio48e_irq_init_hw(struct gpio_chip *gc)
+static int dio48e_irq_init_hw(struct regmap *const map)
 {
-	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
+	unsigned int val;
 
 	/* Disable IRQ by default */
-	inb(dio48egpio->base + 0xB);
-
-	return 0;
+	return regmap_read(map, DIO48E_DISABLE_INTERRUPT, &val);
 }
 
 static int dio48e_probe(struct device *dev, unsigned int id)
 {
-	struct dio48e_gpio *dio48egpio;
 	const char *const name = dev_name(dev);
-	struct gpio_irq_chip *girq;
+	struct i8255_regmap_config config = {};
+	void __iomem *regs;
+	struct regmap *map;
+	struct regmap_config dio48e_regmap_config;
+	struct regmap_config pit_regmap_config;
+	struct i8254_regmap_config pit_config;
 	int err;
-
-	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
-	if (!dio48egpio)
-		return -ENOMEM;
+	struct regmap_irq_chip *chip;
+	struct dio48e_gpio *dio48egpio;
+	struct regmap_irq_chip_data *chip_data;
 
 	if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
@@ -395,59 +238,94 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	dio48egpio->chip.label = name;
-	dio48egpio->chip.parent = dev;
-	dio48egpio->chip.owner = THIS_MODULE;
-	dio48egpio->chip.base = -1;
-	dio48egpio->chip.ngpio = DIO48E_NGPIO;
-	dio48egpio->chip.names = dio48e_names;
-	dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
-	dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
-	dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
-	dio48egpio->chip.get = dio48e_gpio_get;
-	dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
-	dio48egpio->chip.set = dio48e_gpio_set;
-	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
-	dio48egpio->base = base[id];
-
-	girq = &dio48egpio->chip.irq;
-	girq->chip = &dio48e_irqchip;
-	/* This will let us handle the parent IRQ in the driver */
-	girq->parent_handler = NULL;
-	girq->num_parents = 0;
-	girq->parents = NULL;
-	girq->default_type = IRQ_TYPE_NONE;
-	girq->handler = handle_edge_irq;
-	girq->init_hw = dio48e_irq_init_hw;
+	dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
+	if (!dio48egpio)
+		return -ENOMEM;
+
+	regs = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
+	if (!regs)
+		return -ENOMEM;
+
+	dio48egpio->regs = regs;
 
 	raw_spin_lock_init(&dio48egpio->lock);
 
-	/* initialize all GPIO as output */
-	outb(0x80, base[id] + 3);
-	outb(0x00, base[id]);
-	outb(0x00, base[id] + 1);
-	outb(0x00, base[id] + 2);
-	outb(0x00, base[id] + 3);
-	outb(0x80, base[id] + 7);
-	outb(0x00, base[id] + 4);
-	outb(0x00, base[id] + 5);
-	outb(0x00, base[id] + 6);
-	outb(0x00, base[id] + 7);
-
-	err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
-	if (err) {
-		dev_err(dev, "GPIO registering failed (%d)\n", err);
+	dio48e_regmap_config = (struct regmap_config) {
+		.reg_bits = 8,
+		.reg_stride = 1,
+		.val_bits = 8,
+		.lock = dio48e_regmap_lock,
+		.unlock = dio48e_regmap_unlock,
+		.lock_arg = dio48egpio,
+		.io_port = true,
+		.wr_table = &dio48e_wr_table,
+		.rd_table = &dio48e_rd_table,
+		.volatile_table = &dio48e_volatile_table,
+		.precious_table = &dio48e_precious_table,
+		.cache_type = REGCACHE_FLAT,
+	};
+
+	map = devm_regmap_init_mmio(dev, regs, &dio48e_regmap_config);
+	if (IS_ERR(map))
+		return dev_err_probe(dev, PTR_ERR(map),
+				     "Unable to initialize register map\n");
+
+	dio48egpio->map = map;
+
+	pit_regmap_config = (struct regmap_config) {
+		.name = "i8254",
+		.reg_bits = 8,
+		.reg_stride = 1,
+		.val_bits = 8,
+		.lock = pit_regmap_lock,
+		.unlock = pit_regmap_unlock,
+		.lock_arg = dio48egpio,
+		.io_port = true,
+		.wr_table = &pit_wr_table,
+		.rd_table = &pit_rd_table,
+	};
+
+	pit_config.map = devm_regmap_init_mmio(dev, regs, &pit_regmap_config);
+	if (IS_ERR(pit_config.map))
+		return dev_err_probe(dev, PTR_ERR(pit_config.map),
+				     "Unable to initialize i8254 register map\n");
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->name = name;
+	chip->mask_base = DIO48E_ENABLE_INTERRUPT;
+	chip->ack_base = DIO48E_CLEAR_INTERRUPT;
+	chip->no_status = true;
+	chip->num_regs = 1;
+	chip->irqs = dio48e_regmap_irqs;
+	chip->num_irqs = ARRAY_SIZE(dio48e_regmap_irqs);
+	chip->handle_mask_sync = dio48e_handle_mask_sync;
+	chip->irq_drv_data = dio48egpio;
+
+	/* Initialize to prevent spurious interrupts before we're ready */
+	err = dio48e_irq_init_hw(map);
+	if (err)
 		return err;
-	}
 
-	err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
-		dio48egpio);
-	if (err) {
-		dev_err(dev, "IRQ handler registering failed (%d)\n", err);
+	err = devm_regmap_add_irq_chip(dev, map, irq[id], 0, 0, chip, &chip_data);
+	if (err)
+		return dev_err_probe(dev, err, "IRQ registration failed\n");
+
+	pit_config.parent = dev;
+
+	err = devm_i8254_regmap_register(dev, &pit_config);
+	if (err)
 		return err;
-	}
 
-	return 0;
+	config.parent = dev;
+	config.map = map;
+	config.num_ppi = DIO48E_NUM_PPI;
+	config.names = dio48e_names;
+	config.domain = regmap_irq_get_domain(chip_data);
+
+	return devm_i8255_regmap_register(dev, &config);
 }
 
 static struct isa_driver dio48e_driver = {
@@ -456,8 +334,9 @@ static struct isa_driver dio48e_driver = {
 		.name = "104-dio-48e"
 	},
 };
-module_isa_driver(dio48e_driver, num_dio48e);
+module_isa_driver_with_irq(dio48e_driver, num_dio48e, num_irq);
 
 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
 MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("I8254");