diff mbox

[2/5] gpio: Cygnus: add GPIO driver

Message ID 1417826408-1600-3-git-send-email-rjui@broadcom.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ray Jui Dec. 6, 2014, 12:40 a.m. UTC
This GPIO driver supports all 3 GPIO controllers in the Broadcom Cygnus
SoC. The 3 GPIO controllers are 1) the ASIU GPIO controller
("brcm,cygnus-asiu-gpio"), 2) the chipCommonG GPIO controller
("brcm,cygnus-ccm-gpio"), and 3) the ALWAYS-ON GPIO controller
("brcm,cygnus-crmu-gpio")

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
---
 drivers/gpio/Kconfig           |   11 +
 drivers/gpio/Makefile          |    1 +
 drivers/gpio/gpio-bcm-cygnus.c |  719 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 731 insertions(+)
 create mode 100644 drivers/gpio/gpio-bcm-cygnus.c

Comments

Joe Perches Dec. 6, 2014, 1:28 a.m. UTC | #1
On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
> This GPIO driver supports all 3 GPIO controllers in the Broadcom Cygnus
> SoC. The 3 GPIO controllers are 1) the ASIU GPIO controller
> ("brcm,cygnus-asiu-gpio"), 2) the chipCommonG GPIO controller
> ("brcm,cygnus-ccm-gpio"), and 3) the ALWAYS-ON GPIO controller
> ("brcm,cygnus-crmu-gpio")

trivia:

> diff --git a/drivers/gpio/gpio-bcm-cygnus.c b/drivers/gpio/gpio-bcm-cygnus.c

> +static inline struct bcm_cygnus_gpio *to_bcm_cygnus_gpio(
> +		struct gpio_chip *gc)
> +{
> +	return container_of(gc, struct bcm_cygnus_gpio, gc);
> +}

Probably all of these inlines can just be static.

The compiler does a pretty good job these days
of inlining where appropriate.


> +static void bcm_cygnus_gpio_irq_handler(unsigned int irq,
> +		struct irq_desc *desc)
> +{
> +	struct bcm_cygnus_gpio *cygnus_gpio;
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	int i, bit;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	cygnus_gpio = irq_get_handler_data(irq);
> +
> +	/* go through the entire GPIO banks and handle all interrupts */
> +	for (i = 0; i < cygnus_gpio->num_banks; i++) {
> +		unsigned long val = readl(cygnus_gpio->base +
> +				(i * GPIO_BANK_SIZE) +
> +				CYGNUS_GPIO_INT_MSTAT_OFFSET);
> +		if (val) {

This if (val) and indentation isn't really necessary

> +			for_each_set_bit(bit, &val, 32) {

for_each_set_bit will effectively do the if above.

32 bit only code?
otherwise isn't this endian unsafe?

> +				unsigned pin = NGPIOS_PER_BANK * i + bit;
> +				int child_irq =	bcm_cygnus_gpio_to_irq(
> +						&cygnus_gpio->gc, pin);
> +
> +				/*
> +				 * Clear the interrupt before invoking the
> +				 * handler, so we do not leave any window
> +				 */
> +				writel(1 << bit,
> +					cygnus_gpio->base +
> +					(i * GPIO_BANK_SIZE) +
> +					CYGNUS_GPIO_INT_CLR_OFFSET);
> +
> +				generic_handle_irq(child_irq);
> +			}
> +
> +		}
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static void bcm_cygnus_gpio_irq_ack(struct irq_data *d)
> +{
> +	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
> +	unsigned gpio = d->hwirq;
> +	unsigned int offset, shift;
> +	u32 val;
> +
> +	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
> +		CYGNUS_GPIO_INT_CLR_OFFSET;
> +	shift = __gpio_bitpos(cygnus_gpio, gpio);
> +
> +	val = 1 << shift;
> +	writel(val, cygnus_gpio->base + offset);
> +
> +	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
> +			offset, shift);
> +}

> +static struct irq_chip bcm_cygnus_gpio_irq_chip = {
> +	.name = "bcm-cygnus-gpio",
> +	.irq_ack = bcm_cygnus_gpio_irq_ack,
> +	.irq_mask = bcm_cygnus_gpio_irq_mask,
> +	.irq_unmask = bcm_cygnus_gpio_irq_unmask,
> +	.irq_set_type = bcm_cygnus_gpio_irq_set_type,
> +};

const?

> +static struct irq_domain_ops bcm_cygnus_irq_ops = {
> +	.map = bcm_cygnus_gpio_irq_map,
> +	.unmap = bcm_cygnus_gpio_irq_unmap,
> +	.xlate = irq_domain_xlate_twocell,
> +};

const here too?

> +#ifdef CONFIG_OF_GPIO
> +static void bcm_cygnus_gpio_set_pull(struct bcm_cygnus_gpio *cygnus_gpio,
> +		unsigned gpio, enum gpio_pull pull)
> +{
> +	unsigned int offset, shift;
> +	u32 val, up;

	bool up; ?

> +	unsigned long flags;
> +
> +	switch (pull) {
> +	case GPIO_PULL_NONE:
> +		return;
> +	case GPIO_PULL_UP:
> +		up = 1;
> +		break;
> +	case GPIO_PULL_DOWN:
> +		up = 0;
> +		break;
> +	case GPIO_PULL_INVALID:
> +	default:
> +		return;
> +	}

Maybe more sensible to group GPIO_PULL_NONE with GPIO_PULL_INVALID


> +static int bcm_cygnus_gpio_probe(struct platform_device *pdev)
> +{
[]
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "unable to get I/O resource");

missing newline
Ray Jui Dec. 6, 2014, 2:14 a.m. UTC | #2
Thanks for your review, Joe:

On 12/5/2014 5:28 PM, Joe Perches wrote:
> On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
>> This GPIO driver supports all 3 GPIO controllers in the Broadcom Cygnus
>> SoC. The 3 GPIO controllers are 1) the ASIU GPIO controller
>> ("brcm,cygnus-asiu-gpio"), 2) the chipCommonG GPIO controller
>> ("brcm,cygnus-ccm-gpio"), and 3) the ALWAYS-ON GPIO controller
>> ("brcm,cygnus-crmu-gpio")
>
> trivia:
>
>> diff --git a/drivers/gpio/gpio-bcm-cygnus.c b/drivers/gpio/gpio-bcm-cygnus.c
>
>> +static inline struct bcm_cygnus_gpio *to_bcm_cygnus_gpio(
>> +		struct gpio_chip *gc)
>> +{
>> +	return container_of(gc, struct bcm_cygnus_gpio, gc);
>> +}
>
> Probably all of these inlines can just be static.
>
> The compiler does a pretty good job these days
> of inlining where appropriate.

Okay I can remove all inlines.

>
>
>> +static void bcm_cygnus_gpio_irq_handler(unsigned int irq,
>> +		struct irq_desc *desc)
>> +{
>> +	struct bcm_cygnus_gpio *cygnus_gpio;
>> +	struct irq_chip *chip = irq_desc_get_chip(desc);
>> +	int i, bit;
>> +
>> +	chained_irq_enter(chip, desc);
>> +
>> +	cygnus_gpio = irq_get_handler_data(irq);
>> +
>> +	/* go through the entire GPIO banks and handle all interrupts */
>> +	for (i = 0; i < cygnus_gpio->num_banks; i++) {
>> +		unsigned long val = readl(cygnus_gpio->base +
>> +				(i * GPIO_BANK_SIZE) +
>> +				CYGNUS_GPIO_INT_MSTAT_OFFSET);
>> +		if (val) {
>
> This if (val) and indentation isn't really necessary
>

Note for_each_set_bit in this case iterates 32 times searching for bits 
that are set. By having the if (val) check here, it can potentially save 
some of such processing in the ISR. I agree with you that it introduces 
one extra indent here but I think it's required.

>> +			for_each_set_bit(bit, &val, 32) {
>
> for_each_set_bit will effectively do the if above.
>
> 32 bit only code?
> otherwise isn't this endian unsafe?
>

Will change 'unsigned long val' to 'u32 val'.

>> +				unsigned pin = NGPIOS_PER_BANK * i + bit;
>> +				int child_irq =	bcm_cygnus_gpio_to_irq(
>> +						&cygnus_gpio->gc, pin);
>> +
>> +				/*
>> +				 * Clear the interrupt before invoking the
>> +				 * handler, so we do not leave any window
>> +				 */
>> +				writel(1 << bit,
>> +					cygnus_gpio->base +
>> +					(i * GPIO_BANK_SIZE) +
>> +					CYGNUS_GPIO_INT_CLR_OFFSET);
>> +
>> +				generic_handle_irq(child_irq);
>> +			}
>> +
>> +		}
>> +	}
>> +
>> +	chained_irq_exit(chip, desc);
>> +}
>> +
>> +static void bcm_cygnus_gpio_irq_ack(struct irq_data *d)
>> +{
>> +	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
>> +	unsigned gpio = d->hwirq;
>> +	unsigned int offset, shift;
>> +	u32 val;
>> +
>> +	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
>> +		CYGNUS_GPIO_INT_CLR_OFFSET;
>> +	shift = __gpio_bitpos(cygnus_gpio, gpio);
>> +
>> +	val = 1 << shift;
>> +	writel(val, cygnus_gpio->base + offset);
>> +
>> +	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
>> +			offset, shift);
>> +}
>
>> +static struct irq_chip bcm_cygnus_gpio_irq_chip = {
>> +	.name = "bcm-cygnus-gpio",
>> +	.irq_ack = bcm_cygnus_gpio_irq_ack,
>> +	.irq_mask = bcm_cygnus_gpio_irq_mask,
>> +	.irq_unmask = bcm_cygnus_gpio_irq_unmask,
>> +	.irq_set_type = bcm_cygnus_gpio_irq_set_type,
>> +};
>
> const?
>


Sure, will add const to bcm_cygnus_gpio_irq_chip

>> +static struct irq_domain_ops bcm_cygnus_irq_ops = {
>> +	.map = bcm_cygnus_gpio_irq_map,
>> +	.unmap = bcm_cygnus_gpio_irq_unmap,
>> +	.xlate = irq_domain_xlate_twocell,
>> +};
>
> const here too?
>

Yes, will make bcm_cygnus_irq_ops const.

>> +#ifdef CONFIG_OF_GPIO
>> +static void bcm_cygnus_gpio_set_pull(struct bcm_cygnus_gpio *cygnus_gpio,
>> +		unsigned gpio, enum gpio_pull pull)
>> +{
>> +	unsigned int offset, shift;
>> +	u32 val, up;
>
> 	bool up; ?
>

Okay I'll change the name from 'up' to 'pullup' to make it more readable.

>> +	unsigned long flags;
>> +
>> +	switch (pull) {
>> +	case GPIO_PULL_NONE:
>> +		return;
>> +	case GPIO_PULL_UP:
>> +		up = 1;
>> +		break;
>> +	case GPIO_PULL_DOWN:
>> +		up = 0;
>> +		break;
>> +	case GPIO_PULL_INVALID:
>> +	default:
>> +		return;
>> +	}
>
> Maybe more sensible to group GPIO_PULL_NONE with GPIO_PULL_INVALID
>
>

Good suggestion, will do the following:

case GPIO_PULL_NONE:
case GPIO_PULL_INVALID:
default:
        return;

>> +static int bcm_cygnus_gpio_probe(struct platform_device *pdev)
>> +{
> []
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(&pdev->dev, "unable to get I/O resource");
>
> missing newline
>
>

Right, will fix it with dev_err(&pdev->dev, "unable to get I/O resource\n");
Joe Perches Dec. 6, 2014, 2:34 a.m. UTC | #3
On Fri, 2014-12-05 at 18:14 -0800, Ray Jui wrote:
> On 12/5/2014 5:28 PM, Joe Perches wrote:
> > On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
> >> +static void bcm_cygnus_gpio_irq_handler(unsigned int irq,
> >> +		struct irq_desc *desc)
> >> +{
> >> +	struct bcm_cygnus_gpio *cygnus_gpio;
> >> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> >> +	int i, bit;
> >> +
> >> +	chained_irq_enter(chip, desc);
> >> +
> >> +	cygnus_gpio = irq_get_handler_data(irq);
> >> +
> >> +	/* go through the entire GPIO banks and handle all interrupts */
> >> +	for (i = 0; i < cygnus_gpio->num_banks; i++) {
> >> +		unsigned long val = readl(cygnus_gpio->base +
> >> +				(i * GPIO_BANK_SIZE) +
> >> +				CYGNUS_GPIO_INT_MSTAT_OFFSET);
> >> +		if (val) {
> >
> > This if (val) and indentation isn't really necessary
> >
> 
> Note for_each_set_bit in this case iterates 32 times searching for bits 
> that are set.

No it doesn't.

#define for_each_set_bit(bit, addr, size) \
	for ((bit) = find_first_bit((addr), (size));		\
	     (bit) < (size);					\
	     (bit) = find_next_bit((addr), (size), (bit) + 1))

find_first_bit:

 * Returns the bit number of the first set bit.
 * If no bits are set, returns @size.

>  By having the if (val) check here, it can potentially save 
> some of such processing in the ISR. I agree with you that it introduces 
> one extra indent here but I think it's required.
> 
> >> +			for_each_set_bit(bit, &val, 32) {
> >
> > for_each_set_bit will effectively do the if above.
> >
> > 32 bit only code?
> > otherwise isn't this endian unsafe?
> >
> 
> Will change 'unsigned long val' to 'u32 val'.

All the bit operations only work on long *
Ray Jui Dec. 6, 2014, 3:41 a.m. UTC | #4
On 12/5/2014 6:34 PM, Joe Perches wrote:
> On Fri, 2014-12-05 at 18:14 -0800, Ray Jui wrote:
>> On 12/5/2014 5:28 PM, Joe Perches wrote:
>>> On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
>>>> +static void bcm_cygnus_gpio_irq_handler(unsigned int irq,
>>>> +		struct irq_desc *desc)
>>>> +{
>>>> +	struct bcm_cygnus_gpio *cygnus_gpio;
>>>> +	struct irq_chip *chip = irq_desc_get_chip(desc);
>>>> +	int i, bit;
>>>> +
>>>> +	chained_irq_enter(chip, desc);
>>>> +
>>>> +	cygnus_gpio = irq_get_handler_data(irq);
>>>> +
>>>> +	/* go through the entire GPIO banks and handle all interrupts */
>>>> +	for (i = 0; i < cygnus_gpio->num_banks; i++) {
>>>> +		unsigned long val = readl(cygnus_gpio->base +
>>>> +				(i * GPIO_BANK_SIZE) +
>>>> +				CYGNUS_GPIO_INT_MSTAT_OFFSET);
>>>> +		if (val) {
>>>
>>> This if (val) and indentation isn't really necessary
>>>
>>
>> Note for_each_set_bit in this case iterates 32 times searching for bits
>> that are set.
>
> No it doesn't.
>
> #define for_each_set_bit(bit, addr, size) \
> 	for ((bit) = find_first_bit((addr), (size));		\
> 	     (bit) < (size);					\
> 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
>
> find_first_bit:
>
>   * Returns the bit number of the first set bit.
>   * If no bits are set, returns @size.
>

You are right. I reviewed for_each_set_bit but didn't notice 
find_next_bit may simply return 32 in our case without doing any 
iterative processing. I will get rid of the redundant if (val) check below.

>>   By having the if (val) check here, it can potentially save
>> some of such processing in the ISR. I agree with you that it introduces
>> one extra indent here but I think it's required.
>>
>>>> +			for_each_set_bit(bit, &val, 32) {
>>>
>>> for_each_set_bit will effectively do the if above.
>>>
>>> 32 bit only code?
>>> otherwise isn't this endian unsafe?
>>>
>>
>> Will change 'unsigned long val' to 'u32 val'.
>
> All the bit operations only work on long *
>
>

Actually, by reviewing the code more deeply, I'm not sure why using 
for_each_set_bit here is 'endian unsafe'. Isn't that already taken care 
of by macros in bitops.h? Sorry if I'm still missing something here...
Joe Perches Dec. 6, 2014, 4:24 a.m. UTC | #5
On Fri, 2014-12-05 at 19:41 -0800, Ray Jui wrote:
> On 12/5/2014 6:34 PM, Joe Perches wrote:
> > On Fri, 2014-12-05 at 18:14 -0800, Ray Jui wrote:
> >> On 12/5/2014 5:28 PM, Joe Perches wrote:
> >>> On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
> >>>> +			for_each_set_bit(bit, &val, 32) {
[]
> Actually, by reviewing the code more deeply, I'm not sure why using 
> for_each_set_bit here is 'endian unsafe'.

It's not.  The 32 confused me as it was long
and sizeof(long) isn't necessarily 32.

Maybe the 32 should be a #define
Ray Jui Dec. 8, 2014, 1:34 a.m. UTC | #6
On 12/5/2014 8:24 PM, Joe Perches wrote:
> On Fri, 2014-12-05 at 19:41 -0800, Ray Jui wrote:
>> On 12/5/2014 6:34 PM, Joe Perches wrote:
>>> On Fri, 2014-12-05 at 18:14 -0800, Ray Jui wrote:
>>>> On 12/5/2014 5:28 PM, Joe Perches wrote:
>>>>> On Fri, 2014-12-05 at 16:40 -0800, Ray Jui wrote:
>>>>>> +			for_each_set_bit(bit, &val, 32) {
> []
>> Actually, by reviewing the code more deeply, I'm not sure why using
>> for_each_set_bit here is 'endian unsafe'.
>
> It's not.  The 32 confused me as it was long
> and sizeof(long) isn't necessarily 32.
>
> Maybe the 32 should be a #define
>
>
>
Okay, to improve readability, I will change 32 to NGPIOS_PER_BANK.
Ray Jui Dec. 8, 2014, 1:59 a.m. UTC | #7
On 12/5/2014 6:14 PM, Ray Jui wrote:
>>> +static struct irq_chip bcm_cygnus_gpio_irq_chip = {
>>> +    .name = "bcm-cygnus-gpio",
>>> +    .irq_ack = bcm_cygnus_gpio_irq_ack,
>>> +    .irq_mask = bcm_cygnus_gpio_irq_mask,
>>> +    .irq_unmask = bcm_cygnus_gpio_irq_unmask,
>>> +    .irq_set_type = bcm_cygnus_gpio_irq_set_type,
>>> +};
>>
>> const?
>>
>
>
> Sure, will add const to bcm_cygnus_gpio_irq_chip
>
>>> +static struct irq_domain_ops bcm_cygnus_irq_ops = {
>>> +    .map = bcm_cygnus_gpio_irq_map,
>>> +    .unmap = bcm_cygnus_gpio_irq_unmap,
>>> +    .xlate = irq_domain_xlate_twocell,
>>> +};
>>
>> const here too?
>>
>
> Yes, will make bcm_cygnus_irq_ops const.
>
Actually, I cannot make them const here. Note they are passed into other 
APIs which can potentially modifies their values internally.

drivers/gpio/gpio-bcm-cygnus.c: In function ‘bcm_cygnus_gpio_irq_map’:
drivers/gpio/gpio-bcm-cygnus.c:430:4: warning: passing argument 2 of 
‘irq_set_chip_and_handler’ discards ‘const’ qualifier from pointer 
target type [enabled by default]
     handle_simple_irq);
     ^
In file included from drivers/gpio/gpio-bcm-cygnus.c:17:0:
include/linux/irq.h:461:20: note: expected ‘struct irq_chip *’ but 
argument is of type ‘const struct irq_chip *’
  static inline void irq_set_chip_and_handler(unsigned int irq, struct 
irq_chip *chip,
                     ^
drivers/gpio/gpio-bcm-cygnus.c: In function ‘bcm_cygnus_gpio_probe’:
drivers/gpio/gpio-bcm-cygnus.c:679:5: warning: passing argument 2 of 
‘irq_set_chip_and_handler’ discards ‘const’ qualifier from pointer 
target type [enabled by default]
      handle_simple_irq);
      ^
In file included from drivers/gpio/gpio-bcm-cygnus.c:17:0:
include/linux/irq.h:461:20: note: expected ‘struct irq_chip *’ but 
argument is of type ‘const struct irq_chip *’
  static inline void irq_set_chip_and_handler(unsigned int irq, struct 
irq_chip *chip,
diff mbox

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 633ec21..3e3b0342 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -126,6 +126,17 @@  config GPIO_74XX_MMIO
 	    8 bits:	74244 (Input), 74273 (Output)
 	    16 bits:	741624 (Input), 7416374 (Output)
 
+config GPIO_BCM_CYGNUS
+	bool "Broadcom Cygnus GPIO support"
+	depends on ARCH_BCM_CYGNUS && OF_GPIO
+	help
+	  Say yes here to turn on GPIO support for Broadcom Cygnus SoC
+
+	  The Broadcom Cygnus SoC has 3 GPIO controllers including the ASIU
+	  GPIO controller (ASIU), the chipCommonG GPIO controller (CCM), and
+	  the always-ON GPIO controller (CRMU). All 3 GPIO controllers are
+	  supported by this driver
+
 config GPIO_CLPS711X
 	tristate "CLPS711X GPIO support"
 	depends on ARCH_CLPS711X || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 81755f1..31eb7e0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
 obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
 obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
+obj-$(CONFIG_GPIO_BCM_CYGNUS)	+= gpio-bcm-cygnus.o
 obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
diff --git a/drivers/gpio/gpio-bcm-cygnus.c b/drivers/gpio/gpio-bcm-cygnus.c
new file mode 100644
index 0000000..1549ea8
--- /dev/null
+++ b/drivers/gpio/gpio-bcm-cygnus.c
@@ -0,0 +1,719 @@ 
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/ioport.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/irqchip/chained_irq.h>
+
+#define CYGNUS_GPIO_DATA_IN_OFFSET   0x00
+#define CYGNUS_GPIO_DATA_OUT_OFFSET  0x04
+#define CYGNUS_GPIO_OUT_EN_OFFSET    0x08
+#define CYGNUS_GPIO_IN_TYPE_OFFSET   0x0c
+#define CYGNUS_GPIO_INT_DE_OFFSET    0x10
+#define CYGNUS_GPIO_INT_EDGE_OFFSET  0x14
+#define CYGNUS_GPIO_INT_MSK_OFFSET   0x18
+#define CYGNUS_GPIO_INT_STAT_OFFSET  0x1c
+#define CYGNUS_GPIO_INT_MSTAT_OFFSET 0x20
+#define CYGNUS_GPIO_INT_CLR_OFFSET   0x24
+#define CYGNUS_GPIO_PAD_RES_OFFSET   0x34
+#define CYGNUS_GPIO_RES_EN_OFFSET    0x38
+
+/* drive strength control for ASIU GPIO */
+#define CYGNUS_GPIO_ASIU_DRV0_CTRL_OFFSET 0x58
+
+/* drive strength control for CCM GPIO */
+#define CYGNUS_GPIO_CCM_DRV0_CTRL_OFFSET  0x00
+
+#define GPIO_BANK_SIZE 0x200
+#define NGPIOS_PER_BANK 32
+#define GPIO_BIT(pin) ((pin) % NGPIOS_PER_BANK)
+#define GPIO_BANK(pin) ((pin) / NGPIOS_PER_BANK)
+
+#define GPIO_FLAG_BIT_MASK           0xffff
+#define GPIO_PULL_BIT_SHIFT          16
+#define GPIO_PULL_BIT_MASK           0x3
+
+#define GPIO_DRV_STRENGTH_BIT_SHIFT  20
+#define GPIO_DRV_STRENGTH_BITS       3
+#define GPIO_DRV_STRENGTH_BIT_MASK   ((1 << GPIO_DRV_STRENGTH_BITS) - 1)
+
+/*
+ * For GPIO internal pull up/down registers
+ */
+enum gpio_pull {
+	GPIO_PULL_NONE = 0,
+	GPIO_PULL_UP,
+	GPIO_PULL_DOWN,
+	GPIO_PULL_INVALID,
+};
+
+/*
+ * GPIO drive strength
+ */
+enum gpio_drv_strength {
+	GPIO_DRV_STRENGTH_2MA = 0,
+	GPIO_DRV_STRENGTH_4MA,
+	GPIO_DRV_STRENGTH_6MA,
+	GPIO_DRV_STRENGTH_8MA,
+	GPIO_DRV_STRENGTH_10MA,
+	GPIO_DRV_STRENGTH_12MA,
+	GPIO_DRV_STRENGTH_14MA,
+	GPIO_DRV_STRENGTH_16MA,
+	GPIO_DRV_STRENGTH_INVALID,
+};
+
+struct bcm_cygnus_gpio {
+	struct device *dev;
+	void __iomem *base;
+	void __iomem *io_ctrl;
+	spinlock_t lock;
+	struct gpio_chip gc;
+	unsigned num_banks;
+	int irq;
+	struct irq_domain *irq_domain;
+};
+
+static unsigned int gpio_base_index;
+
+static inline struct bcm_cygnus_gpio *to_bcm_cygnus_gpio(
+		struct gpio_chip *gc)
+{
+	return container_of(gc, struct bcm_cygnus_gpio, gc);
+}
+
+static inline int bcm_cygnus_gpio_to_irq(struct gpio_chip *gc,
+		unsigned offset)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+
+	return irq_find_mapping(cygnus_gpio->irq_domain, offset);
+}
+
+static inline unsigned int __gpio_reg_offset(
+		struct bcm_cygnus_gpio *cygnus_gpio,
+		unsigned gpio)
+{
+	return GPIO_BANK(gpio) * GPIO_BANK_SIZE;
+}
+
+static inline unsigned int __gpio_bitpos(struct bcm_cygnus_gpio *cygnus_gpio,
+		unsigned gpio)
+{
+	return GPIO_BIT(gpio);
+}
+
+static void bcm_cygnus_gpio_irq_handler(unsigned int irq,
+		struct irq_desc *desc)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio;
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	int i, bit;
+
+	chained_irq_enter(chip, desc);
+
+	cygnus_gpio = irq_get_handler_data(irq);
+
+	/* go through the entire GPIO banks and handle all interrupts */
+	for (i = 0; i < cygnus_gpio->num_banks; i++) {
+		unsigned long val = readl(cygnus_gpio->base +
+				(i * GPIO_BANK_SIZE) +
+				CYGNUS_GPIO_INT_MSTAT_OFFSET);
+		if (val) {
+			for_each_set_bit(bit, &val, 32) {
+				unsigned pin = NGPIOS_PER_BANK * i + bit;
+				int child_irq =	bcm_cygnus_gpio_to_irq(
+						&cygnus_gpio->gc, pin);
+
+				/*
+				 * Clear the interrupt before invoking the
+				 * handler, so we do not leave any window
+				 */
+				writel(1 << bit,
+					cygnus_gpio->base +
+					(i * GPIO_BANK_SIZE) +
+					CYGNUS_GPIO_INT_CLR_OFFSET);
+
+				generic_handle_irq(child_irq);
+			}
+
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void bcm_cygnus_gpio_irq_ack(struct irq_data *d)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->hwirq;
+	unsigned int offset, shift;
+	u32 val;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_INT_CLR_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	val = 1 << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
+			offset, shift);
+}
+
+static void bcm_cygnus_gpio_irq_mask(struct irq_data *d)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->hwirq;
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_INT_MSK_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
+			offset, shift);
+}
+
+static void bcm_cygnus_gpio_irq_unmask(struct irq_data *d)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->hwirq;
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_INT_MSK_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	val = readl(cygnus_gpio->base + offset);
+	val |= 1 << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
+			offset, shift);
+}
+
+static int bcm_cygnus_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->hwirq;
+	unsigned int int_type, dual_edge, edge_lvl;
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+		int_type = 0;
+		dual_edge = 0;
+		edge_lvl = 1;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		int_type = 0;
+		dual_edge = 0;
+		edge_lvl = 0;
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		int_type = 0;
+		dual_edge = 1;
+		edge_lvl = 0;
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		int_type = 1;
+		dual_edge = 0;
+		edge_lvl = 1;
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		int_type = 1;
+		dual_edge = 0;
+		edge_lvl = 0;
+		break;
+
+	default:
+		dev_err(cygnus_gpio->dev, "invalid GPIO irq type 0x%x\n", type);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_IN_TYPE_OFFSET;
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	val |= int_type << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_INT_DE_OFFSET;
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	val |= dual_edge << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_INT_EDGE_OFFSET;
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	val |= edge_lvl << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	return 0;
+}
+
+static struct irq_chip bcm_cygnus_gpio_irq_chip = {
+	.name = "bcm-cygnus-gpio",
+	.irq_ack = bcm_cygnus_gpio_irq_ack,
+	.irq_mask = bcm_cygnus_gpio_irq_mask,
+	.irq_unmask = bcm_cygnus_gpio_irq_unmask,
+	.irq_set_type = bcm_cygnus_gpio_irq_set_type,
+};
+
+static int bcm_cygnus_gpio_direction_input(struct gpio_chip *gc,
+		unsigned gpio)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_OUT_EN_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
+			offset, shift);
+
+	return 0;
+}
+
+static int bcm_cygnus_gpio_direction_output(struct gpio_chip *gc,
+		unsigned gpio, int value)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_OUT_EN_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	val = readl(cygnus_gpio->base + offset);
+	val |= 1 << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u\n", gpio,
+			offset, shift);
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_DATA_OUT_OFFSET;
+
+	val = readl(cygnus_gpio->base + offset);
+	if (value)
+		val |= 1 << shift;
+	else
+		val &= ~(1 << shift);
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	dev_dbg(cygnus_gpio->dev,
+		"gpio:%u offset:0x%04x shift:%u val:0x%08x\n",
+		gpio, offset, shift, val);
+
+	return 0;
+}
+
+static void bcm_cygnus_gpio_set(struct gpio_chip *gc, unsigned gpio,
+		int value)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+	unsigned int offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_DATA_OUT_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	val = readl(cygnus_gpio->base + offset);
+	if (value)
+		val |= 1 << shift;
+	else
+		val &= ~(1 << shift);
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+
+	dev_dbg(cygnus_gpio->dev,
+		"gpio:%u offset:0x%04x shift:%u val:0x%08x\n",
+		gpio, offset, shift, val);
+}
+
+static int bcm_cygnus_gpio_get(struct gpio_chip *gc, unsigned gpio)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+	unsigned int offset, shift;
+	u32 val;
+
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_DATA_IN_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	val = readl(cygnus_gpio->base + offset);
+	val = (val >> shift) & 1;
+
+	dev_dbg(cygnus_gpio->dev, "gpio:%u offset:0x%04x shift:%u val:%u\n",
+			gpio, offset, shift, val);
+
+	return val;
+}
+
+static struct lock_class_key gpio_lock_class;
+
+static int bcm_cygnus_gpio_irq_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	int ret;
+
+	ret = irq_set_chip_data(irq, d->host_data);
+	if (ret < 0)
+		return ret;
+	irq_set_lockdep_class(irq, &gpio_lock_class);
+	irq_set_chip_and_handler(irq, &bcm_cygnus_gpio_irq_chip,
+			handle_simple_irq);
+	set_irq_flags(irq, IRQF_VALID);
+
+	return 0;
+}
+
+static void bcm_cygnus_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static struct irq_domain_ops bcm_cygnus_irq_ops = {
+	.map = bcm_cygnus_gpio_irq_map,
+	.unmap = bcm_cygnus_gpio_irq_unmap,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+#ifdef CONFIG_OF_GPIO
+static void bcm_cygnus_gpio_set_pull(struct bcm_cygnus_gpio *cygnus_gpio,
+		unsigned gpio, enum gpio_pull pull)
+{
+	unsigned int offset, shift;
+	u32 val, up;
+	unsigned long flags;
+
+	switch (pull) {
+	case GPIO_PULL_NONE:
+		return;
+	case GPIO_PULL_UP:
+		up = 1;
+		break;
+	case GPIO_PULL_DOWN:
+		up = 0;
+		break;
+	case GPIO_PULL_INVALID:
+	default:
+		return;
+	}
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	/* set pull up/down */
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_PAD_RES_OFFSET;
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	val = readl(cygnus_gpio->base + offset);
+	val &= ~(1 << shift);
+	if (up)
+		val |= 1 << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	/* enable pad */
+	offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+		CYGNUS_GPIO_RES_EN_OFFSET;
+	val = readl(cygnus_gpio->base + offset);
+	val |= 1 << shift;
+	writel(val, cygnus_gpio->base + offset);
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+}
+
+static void bcm_cygnus_gpio_set_strength(struct bcm_cygnus_gpio *cygnus_gpio,
+		unsigned gpio, enum gpio_drv_strength strength)
+{
+	struct device *dev = cygnus_gpio->dev;
+	void __iomem *base;
+	unsigned int i, offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	if (of_device_is_compatible(dev->of_node, "brcm,cygnus-asiu-gpio")) {
+		base = cygnus_gpio->base;
+		offset = __gpio_reg_offset(cygnus_gpio, gpio) +
+			CYGNUS_GPIO_ASIU_DRV0_CTRL_OFFSET;
+	} else if (of_device_is_compatible(dev->of_node,
+			"brcm,cygnus-ccm-gpio")) {
+		if (!cygnus_gpio->io_ctrl)
+			return;
+
+		base = cygnus_gpio->io_ctrl;
+		offset = CYGNUS_GPIO_CCM_DRV0_CTRL_OFFSET;
+	} else
+		return;
+
+	shift = __gpio_bitpos(cygnus_gpio, gpio);
+
+	spin_lock_irqsave(&cygnus_gpio->lock, flags);
+
+	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
+		val = readl(base + offset);
+		val &= ~(1 << shift);
+		val |= ((strength >> i) & 0x1) << shift;
+		writel(val, base + offset);
+		offset += 4;
+	}
+
+	spin_unlock_irqrestore(&cygnus_gpio->lock, flags);
+}
+
+static int bcm_cygnus_gpio_of_xlate(struct gpio_chip *gc,
+		const struct of_phandle_args *gpiospec, u32 *flags)
+{
+	struct bcm_cygnus_gpio *cygnus_gpio = to_bcm_cygnus_gpio(gc);
+	enum gpio_pull pull;
+	enum gpio_drv_strength strength;
+
+	if (gc->of_gpio_n_cells < 2)
+		return -EINVAL;
+
+	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
+		return -EINVAL;
+
+	if (gpiospec->args[0] >= gc->ngpio)
+		return -EINVAL;
+
+	pull = (gpiospec->args[1] >> GPIO_PULL_BIT_SHIFT) & GPIO_PULL_BIT_MASK;
+	if (WARN_ON(pull >= GPIO_PULL_INVALID))
+		return -EINVAL;
+
+	strength = (gpiospec->args[1] >> GPIO_DRV_STRENGTH_BIT_SHIFT) &
+		GPIO_DRV_STRENGTH_BIT_MASK;
+
+	if (flags)
+		*flags = gpiospec->args[1] & GPIO_FLAG_BIT_MASK;
+
+	bcm_cygnus_gpio_set_pull(cygnus_gpio, gpiospec->args[0], pull);
+	bcm_cygnus_gpio_set_strength(cygnus_gpio, gpiospec->args[0], strength);
+
+	return gpiospec->args[0];
+}
+#endif
+
+static const struct of_device_id bcm_cygnus_gpio_of_match[] = {
+	{ .compatible = "brcm,cygnus-crmu-gpio" },
+	{ .compatible = "brcm,cygnus-asiu-gpio" },
+	{ .compatible = "brcm,cygnus-ccm-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, bcm_cygnus_gpio_of_match);
+
+static int bcm_cygnus_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *match;
+	struct resource *res;
+	struct bcm_cygnus_gpio *cygnus_gpio;
+	struct gpio_chip *gc;
+	u32 i, ngpios;
+	int ret;
+
+	match = of_match_device(bcm_cygnus_gpio_of_match, dev);
+	if (!match) {
+		dev_err(&pdev->dev, "failed to find GPIO controller\n");
+		return -ENODEV;
+	}
+
+	cygnus_gpio = devm_kzalloc(dev, sizeof(*cygnus_gpio), GFP_KERNEL);
+	if (!cygnus_gpio)
+		return -ENOMEM;
+
+	cygnus_gpio->dev = dev;
+	platform_set_drvdata(pdev, cygnus_gpio);
+
+	if (of_property_read_u32(dev->of_node, "ngpios", &ngpios)) {
+		dev_err(&pdev->dev, "missing ngpios device tree property\n");
+		return -ENODEV;
+	}
+	cygnus_gpio->num_banks = (ngpios + NGPIOS_PER_BANK - 1) /
+		NGPIOS_PER_BANK;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "unable to get I/O resource");
+		return -ENODEV;
+	}
+
+	cygnus_gpio->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cygnus_gpio->base)) {
+		dev_err(&pdev->dev, "unable to map I/O memory\n");
+		return PTR_ERR(cygnus_gpio->base);
+	}
+
+	/*
+	 * Only certain types of Cygnus GPIO interfaces have I/O control
+	 * registers
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res) {
+		cygnus_gpio->io_ctrl = devm_ioremap_resource(dev, res);
+		if (IS_ERR(cygnus_gpio->io_ctrl)) {
+			dev_err(&pdev->dev, "unable to map I/O memory\n");
+			return PTR_ERR(cygnus_gpio->io_ctrl);
+		}
+	}
+
+	spin_lock_init(&cygnus_gpio->lock);
+
+	gc = &cygnus_gpio->gc;
+	gc->base = gpio_base_index;
+	gpio_base_index += ngpios;
+	gc->ngpio = ngpios;
+	gc->label = dev_name(dev);
+	gc->dev = dev;
+#ifdef CONFIG_OF_GPIO
+	gc->of_node = dev->of_node;
+	gc->of_gpio_n_cells = 2;
+	gc->of_xlate = bcm_cygnus_gpio_of_xlate;
+#endif
+	gc->direction_input = bcm_cygnus_gpio_direction_input;
+	gc->direction_output = bcm_cygnus_gpio_direction_output;
+	gc->set = bcm_cygnus_gpio_set;
+	gc->get = bcm_cygnus_gpio_get;
+	gc->to_irq = bcm_cygnus_gpio_to_irq;
+
+	ret = gpiochip_add(gc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to add GPIO chip\n");
+		goto err_dec_gpio_base;
+	}
+
+	/*
+	 * Some of the GPIO interfaces do not have interrupt wired to the main
+	 * processor
+	 */
+	if (of_find_property(dev->of_node, "no-interrupt", NULL))
+		return 0;
+
+	cygnus_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
+			gc->ngpio, &bcm_cygnus_irq_ops, cygnus_gpio);
+	if (!cygnus_gpio->irq_domain) {
+		dev_err(&pdev->dev, "unable to allocate IRQ domain\n");
+		ret = -ENXIO;
+		goto err_rm_gpiochip;
+	}
+
+	cygnus_gpio->irq = platform_get_irq(pdev, 0);
+	if (cygnus_gpio->irq < 0) {
+		dev_err(&pdev->dev, "unable to get IRQ\n");
+		ret = cygnus_gpio->irq;
+		goto err_rm_irq_domain;
+	}
+
+	for (i = 0; i < gc->ngpio; i++) {
+		int irq = irq_create_mapping(cygnus_gpio->irq_domain, i);
+
+		irq_set_lockdep_class(irq, &gpio_lock_class);
+		irq_set_chip_data(irq, cygnus_gpio);
+		irq_set_chip_and_handler(irq, &bcm_cygnus_gpio_irq_chip,
+				handle_simple_irq);
+		set_irq_flags(irq, IRQF_VALID);
+	}
+
+	irq_set_chained_handler(cygnus_gpio->irq, bcm_cygnus_gpio_irq_handler);
+	irq_set_handler_data(cygnus_gpio->irq, cygnus_gpio);
+
+	return 0;
+
+err_rm_irq_domain:
+	irq_domain_remove(cygnus_gpio->irq_domain);
+
+err_rm_gpiochip:
+	gpiochip_remove(gc);
+
+err_dec_gpio_base:
+	gpio_base_index -= ngpios;
+	return ret;
+}
+
+static struct platform_driver bcm_cygnus_gpio_driver = {
+	.driver = {
+		.name = "bcm-cygnus-gpio",
+		.owner = THIS_MODULE,
+		.of_match_table = bcm_cygnus_gpio_of_match,
+	},
+	.probe = bcm_cygnus_gpio_probe,
+};
+
+module_platform_driver(bcm_cygnus_gpio_driver);
+
+MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Cygnus GPIO Driver");
+MODULE_LICENSE("GPL v2");