[v5,6/8] pinctrl: cygnus: add gpio/pinconf driver
diff mbox

Message ID 1425515756-321-7-git-send-email-rjui@broadcom.com
State New
Headers show

Commit Message

Ray Jui March 5, 2015, 12:35 a.m. UTC
This adds the initial support of the Broadcom Cygnus GPIO/PINCONF driver
that supports all 3 GPIO controllers on Cygnus including the ASIU GPIO
controller, the chipCommonG GPIO controller, and the always-on GPIO
controller. Basic PINCONF configurations such as bias pull up/down, and
drive strength are also supported in this driver.

Pins from the ASIU GPIO controller can be individually muxed to GPIO
function, through interaction with the Cygnus IOMUX controller

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Tested-by: Dmitry Torokhov <dtor@chromium.org>
---
 drivers/pinctrl/bcm/Kconfig               |   22 +
 drivers/pinctrl/bcm/Makefile              |    1 +
 drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c |  884 +++++++++++++++++++++++++++++
 3 files changed, 907 insertions(+)
 create mode 100644 drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c

Comments

Paul Bolle March 5, 2015, 8:11 a.m. UTC | #1
On Wed, 2015-03-04 at 16:35 -0800, Ray Jui wrote:
> --- a/drivers/pinctrl/bcm/Kconfig
> +++ b/drivers/pinctrl/bcm/Kconfig
> @@ -20,6 +20,28 @@ config PINCTRL_BCM2835
>  	select PINMUX
>  	select PINCONF
>  
> +config PINCTRL_CYGNUS_GPIO
> +	bool "Broadcom Cygnus GPIO (with PINCONF) driver"

bool type.

> +	depends on OF_GPIO && ARCH_BCM_CYGNUS
> +	select GPIOLIB_IRQCHIP
> +	select PINCONF
> +	select GENERIC_PINCONF
> +	default ARCH_BCM_CYGNUS
> +	help
> +	  Say yes here to enable the Broadcom Cygnus GPIO driver.
> +
> +	  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/AON). All 3 GPIO controllers are
> +	  supported by this driver.
> +
> +	  All 3 Cygnus GPIO controllers support basic PINCONF functions such
> +	  as bias pull up, pull down, and drive strength configurations, when
> +	  these pins are muxed to GPIO.
> +
> +	  Pins from the ASIU GPIO can be individually muxed to GPIO function,
> +	  through interaction with the Cygnus IOMUX controller.
> +
>  config PINCTRL_CYGNUS_MUX
>  	bool "Broadcom Cygnus IOMUX driver"
>  	depends on (ARCH_BCM_CYGNUS || COMPILE_TEST)
> diff --git a/drivers/pinctrl/bcm/Makefile b/drivers/pinctrl/bcm/Makefile
> index bb6beb6..2b2f70e 100644
> --- a/drivers/pinctrl/bcm/Makefile
> +++ b/drivers/pinctrl/bcm/Makefile
> @@ -2,4 +2,5 @@
>  
>  obj-$(CONFIG_PINCTRL_BCM281XX)		+= pinctrl-bcm281xx.o
>  obj-$(CONFIG_PINCTRL_BCM2835)		+= pinctrl-bcm2835.o
> +obj-$(CONFIG_PINCTRL_CYGNUS_GPIO)	+= pinctrl-cygnus-gpio.o

So pinctrl-cygnus-gpio. will be built-in or not built at all.

>  obj-$(CONFIG_PINCTRL_CYGNUS_MUX)	+= pinctrl-cygnus-mux.o
> diff --git a/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c b/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c
> new file mode 100644
> index 0000000..4687284
> --- /dev/null
> +++ b/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c
> @@ -0,0 +1,884 @@

[...]

> +MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
> +MODULE_DESCRIPTION("Broadcom Cygnus GPIO Driver");
> +MODULE_LICENSE("GPL v2");

These three macros will be preprocessed away. (There's also
MODULE_DEVICE_TABLE. I don't yet know how that is handled in a
non-modular build, sorry.)


Paul Bolle

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Paul Bolle March 5, 2015, 8:36 a.m. UTC | #2
On Thu, 2015-03-05 at 09:11 +0100, Paul Bolle wrote:
> On Wed, 2015-03-04 at 16:35 -0800, Ray Jui wrote:
> > +MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
> > +MODULE_DESCRIPTION("Broadcom Cygnus GPIO Driver");
> > +MODULE_LICENSE("GPL v2");
> 
> These three macros will be preprocessed away. (There's also
> MODULE_DEVICE_TABLE. I don't yet know how that is handled in a
> non-modular build, sorry.)

It turns out MODULE_DEVICE_TABLE is _really_ preprocessed away. See
include/linux/module.h:
    #ifdef MODULE
    /* Creates an alias so file2alias.c can find device table. */
    #define MODULE_DEVICE_TABLE(type, name)                                 \
    extern const typeof(name) __mod_##type##__##name##_device_table         \
      __attribute__ ((unused, alias(__stringify(name))))
    #else  /* !MODULE */
    #define MODULE_DEVICE_TABLE(type, name)
    #endif


Did I get that right?

(I knew the other three MODULE_* macros are handled in slightly more
complicated way, but the effect is basically that they are preprocessed
away.)


Paul Bolle

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Ray Jui March 5, 2015, 5:13 p.m. UTC | #3
Hi Paul,

On 3/5/2015 12:36 AM, Paul Bolle wrote:
> On Thu, 2015-03-05 at 09:11 +0100, Paul Bolle wrote:
>> On Wed, 2015-03-04 at 16:35 -0800, Ray Jui wrote:
>>> +MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
>>> +MODULE_DESCRIPTION("Broadcom Cygnus GPIO Driver");
>>> +MODULE_LICENSE("GPL v2");
>>
>> These three macros will be preprocessed away. (There's also
>> MODULE_DEVICE_TABLE. I don't yet know how that is handled in a
>> non-modular build, sorry.)
> 
> It turns out MODULE_DEVICE_TABLE is _really_ preprocessed away. See
> include/linux/module.h:
>     #ifdef MODULE
>     /* Creates an alias so file2alias.c can find device table. */
>     #define MODULE_DEVICE_TABLE(type, name)                                 \
>     extern const typeof(name) __mod_##type##__##name##_device_table         \
>       __attribute__ ((unused, alias(__stringify(name))))
>     #else  /* !MODULE */
>     #define MODULE_DEVICE_TABLE(type, name)
>     #endif
> 
> 
> Did I get that right?
> 
> (I knew the other three MODULE_* macros are handled in slightly more
> complicated way, but the effect is basically that they are preprocessed
> away.)
> 
> 
> Paul Bolle
> 

Even these module macros will be pre-processed away when the driver is
statically linked (and yes, I'm not planning to ever make these driver
built as module), I'm not too sure about the convention here. I thought
that they are still good to be in the driver for information purpose.
I'm seeing other pinctrl drivers doing this as well.

Maybe Linus can help to clarify this?

Thanks,

Ray
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Linus Walleij March 9, 2015, 4:41 p.m. UTC | #4
On Thu, Mar 5, 2015 at 6:13 PM, Ray Jui <rjui@broadcom.com> wrote:

>> (I knew the other three MODULE_* macros are handled in slightly more
>> complicated way, but the effect is basically that they are preprocessed
>> away.)
>>
>> Paul Bolle
>
> Even these module macros will be pre-processed away when the driver is
> statically linked (and yes, I'm not planning to ever make these driver
> built as module), I'm not too sure about the convention here. I thought
> that they are still good to be in the driver for information purpose.
> I'm seeing other pinctrl drivers doing this as well.
>
> Maybe Linus can help to clarify this?

As pointed out in another mail on similar subject, I think these macros
are a kind of obsolete documentation and if they should be dropped we
need to go over an entire subsystem at a time and remove all boolean users
in a big patch.

Yours,
Linus Walleij
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Paul Bolle March 9, 2015, 6:47 p.m. UTC | #5
Linus Walleij schreef op ma 09-03-2015 om 17:41 [+0100]:
> As pointed out in another mail on similar subject, I think these macros
> are a kind of obsolete documentation and if they should be dropped we
> need to go over an entire subsystem at a time and remove all boolean users
> in a big patch.

And, as I stated in that other thread, we could start by first checking
for things like this during review. (And if people were to do clean up
patches I'd suggest to do them one driver at a time. Just to keep things
manageable.)


Paul Bolle

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Patch
diff mbox

diff --git a/drivers/pinctrl/bcm/Kconfig b/drivers/pinctrl/bcm/Kconfig
index eb13201..cd11d4d 100644
--- a/drivers/pinctrl/bcm/Kconfig
+++ b/drivers/pinctrl/bcm/Kconfig
@@ -20,6 +20,28 @@  config PINCTRL_BCM2835
 	select PINMUX
 	select PINCONF
 
+config PINCTRL_CYGNUS_GPIO
+	bool "Broadcom Cygnus GPIO (with PINCONF) driver"
+	depends on OF_GPIO && ARCH_BCM_CYGNUS
+	select GPIOLIB_IRQCHIP
+	select PINCONF
+	select GENERIC_PINCONF
+	default ARCH_BCM_CYGNUS
+	help
+	  Say yes here to enable the Broadcom Cygnus GPIO driver.
+
+	  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/AON). All 3 GPIO controllers are
+	  supported by this driver.
+
+	  All 3 Cygnus GPIO controllers support basic PINCONF functions such
+	  as bias pull up, pull down, and drive strength configurations, when
+	  these pins are muxed to GPIO.
+
+	  Pins from the ASIU GPIO can be individually muxed to GPIO function,
+	  through interaction with the Cygnus IOMUX controller.
+
 config PINCTRL_CYGNUS_MUX
 	bool "Broadcom Cygnus IOMUX driver"
 	depends on (ARCH_BCM_CYGNUS || COMPILE_TEST)
diff --git a/drivers/pinctrl/bcm/Makefile b/drivers/pinctrl/bcm/Makefile
index bb6beb6..2b2f70e 100644
--- a/drivers/pinctrl/bcm/Makefile
+++ b/drivers/pinctrl/bcm/Makefile
@@ -2,4 +2,5 @@ 
 
 obj-$(CONFIG_PINCTRL_BCM281XX)		+= pinctrl-bcm281xx.o
 obj-$(CONFIG_PINCTRL_BCM2835)		+= pinctrl-bcm2835.o
+obj-$(CONFIG_PINCTRL_CYGNUS_GPIO)	+= pinctrl-cygnus-gpio.o
 obj-$(CONFIG_PINCTRL_CYGNUS_MUX)	+= pinctrl-cygnus-mux.o
diff --git a/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c b/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c
new file mode 100644
index 0000000..4687284
--- /dev/null
+++ b/drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c
@@ -0,0 +1,884 @@ 
+/*
+ * Copyright (C) 2014-2015 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.
+ *
+ * This file contains the Broadcom Cygnus GPIO driver that supports 3
+ * GPIO controllers on Cygnus including the ASIU GPIO controller, the
+ * chipCommonG GPIO controller, and the always-on GPIO controller. Basic
+ * PINCONF such as bias pull up/down, and drive strength are also supported
+ * in this driver.
+ *
+ * Pins from the ASIU GPIO can be individually muxed to GPIO function,
+ * through the interaction with the Cygnus IOMUX controller
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.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/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+
+#include "../pinctrl-utils.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/CRMU (AON) GPIO */
+#define CYGNUS_GPIO_DRV0_CTRL_OFFSET  0x00
+
+#define GPIO_BANK_SIZE 0x200
+#define NGPIOS_PER_BANK 32
+#define GPIO_BANK(pin) ((pin) / NGPIOS_PER_BANK)
+
+#define CYGNUS_GPIO_REG(pin, reg) (GPIO_BANK(pin) * GPIO_BANK_SIZE + (reg))
+#define CYGNUS_GPIO_SHIFT(pin) ((pin) % NGPIOS_PER_BANK)
+
+#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)
+
+/*
+ * Cygnus GPIO core
+ *
+ * @dev: pointer to device
+ * @base: I/O register base for Cygnus GPIO controller
+ * @io_ctrl: I/O register base for certain type of Cygnus GPIO controller that
+ * has the PINCONF support implemented outside of the GPIO block
+ * @lock: lock to protect access to I/O registers
+ * @gc: GPIO chip
+ * @num_banks: number of GPIO banks, each bank supports up to 32 GPIOs
+ * @pinmux_is_supported: flag to indicate this GPIO controller contains pins
+ * that can be individually muxed to GPIO
+ * @pctl: pointer to pinctrl_dev
+ * @pctldesc: pinctrl descriptor
+ */
+struct cygnus_gpio {
+	struct device *dev;
+
+	void __iomem *base;
+	void __iomem *io_ctrl;
+
+	spinlock_t lock;
+
+	struct gpio_chip gc;
+	unsigned num_banks;
+
+	bool pinmux_is_supported;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc pctldesc;
+};
+
+static inline struct cygnus_gpio *to_cygnus_gpio(struct gpio_chip *gc)
+{
+	return container_of(gc, struct cygnus_gpio, gc);
+}
+
+/*
+ * Mapping from PINCONF pins to GPIO pins is 1-to-1
+ */
+static inline unsigned cygnus_pin_to_gpio(unsigned pin)
+{
+	return pin;
+}
+
+/**
+ *  cygnus_set_bit - set or clear one bit (corresponding to the GPIO pin) in a
+ *  Cygnus GPIO register
+ *
+ *  @cygnus_gpio: Cygnus GPIO device
+ *  @reg: register offset
+ *  @gpio: GPIO pin
+ *  @set: set or clear
+ */
+static inline void cygnus_set_bit(struct cygnus_gpio *chip, unsigned int reg,
+				  unsigned gpio, bool set)
+{
+	unsigned int offset = CYGNUS_GPIO_REG(gpio, reg);
+	unsigned int shift = CYGNUS_GPIO_SHIFT(gpio);
+	u32 val;
+
+	val = readl(chip->base + offset);
+	if (set)
+		val |= BIT(shift);
+	else
+		val &= ~BIT(shift);
+	writel(val, chip->base + offset);
+}
+
+static inline bool cygnus_get_bit(struct cygnus_gpio *chip, unsigned int reg,
+				  unsigned gpio)
+{
+	unsigned int offset = CYGNUS_GPIO_REG(gpio, reg);
+	unsigned int shift = CYGNUS_GPIO_SHIFT(gpio);
+
+	return !!(readl(chip->base + offset) & BIT(shift));
+}
+
+static void cygnus_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	struct irq_chip *irq_chip = irq_desc_get_chip(desc);
+	int i, bit;
+
+	chained_irq_enter(irq_chip, desc);
+
+	/* go through the entire GPIO banks and handle all interrupts */
+	for (i = 0; i < chip->num_banks; i++) {
+		unsigned long val = readl(chip->base + (i * GPIO_BANK_SIZE) +
+					  CYGNUS_GPIO_INT_MSTAT_OFFSET);
+
+		for_each_set_bit(bit, &val, NGPIOS_PER_BANK) {
+			unsigned pin = NGPIOS_PER_BANK * i + bit;
+			int child_irq = irq_find_mapping(gc->irqdomain, pin);
+
+			/*
+			 * Clear the interrupt before invoking the
+			 * handler, so we do not leave any window
+			 */
+			writel(BIT(bit), chip->base + (i * GPIO_BANK_SIZE) +
+			       CYGNUS_GPIO_INT_CLR_OFFSET);
+
+			generic_handle_irq(child_irq);
+		}
+	}
+
+	chained_irq_exit(irq_chip, desc);
+}
+
+
+static void cygnus_gpio_irq_ack(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned gpio = d->hwirq;
+	unsigned int offset = CYGNUS_GPIO_REG(gpio,
+			CYGNUS_GPIO_INT_CLR_OFFSET);
+	unsigned int shift = CYGNUS_GPIO_SHIFT(gpio);
+	u32 val = BIT(shift);
+
+	writel(val, chip->base + offset);
+}
+
+/**
+ *  cygnus_gpio_irq_set_mask - mask/unmask a GPIO interrupt
+ *
+ *  @d: IRQ chip data
+ *  @unmask: mask/unmask GPIO interrupt
+ */
+static void cygnus_gpio_irq_set_mask(struct irq_data *d, bool unmask)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned gpio = d->hwirq;
+
+	cygnus_set_bit(chip, CYGNUS_GPIO_INT_MSK_OFFSET, gpio, unmask);
+}
+
+static void cygnus_gpio_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_gpio_irq_set_mask(d, false);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static void cygnus_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_gpio_irq_set_mask(d, true);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int cygnus_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned gpio = d->hwirq;
+	bool level_triggered = false;
+	bool dual_edge = false;
+	bool rising_or_high = false;
+	unsigned long flags;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+		rising_or_high = true;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		dual_edge = true;
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		level_triggered = true;
+		rising_or_high = true;
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		level_triggered = true;
+		break;
+
+	default:
+		dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
+			type);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_set_bit(chip, CYGNUS_GPIO_IN_TYPE_OFFSET, gpio,
+		       level_triggered);
+	cygnus_set_bit(chip, CYGNUS_GPIO_INT_DE_OFFSET, gpio, dual_edge);
+	cygnus_set_bit(chip, CYGNUS_GPIO_INT_EDGE_OFFSET, gpio,
+		       rising_or_high);
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	dev_dbg(chip->dev,
+		"gpio:%u level_triggered:%d dual_edge:%d rising_or_high:%d\n",
+		gpio, level_triggered, dual_edge, rising_or_high);
+
+	return 0;
+}
+
+static struct irq_chip cygnus_gpio_irq_chip = {
+	.name = "bcm-cygnus-gpio",
+	.irq_ack = cygnus_gpio_irq_ack,
+	.irq_mask = cygnus_gpio_irq_mask,
+	.irq_unmask = cygnus_gpio_irq_unmask,
+	.irq_set_type = cygnus_gpio_irq_set_type,
+};
+
+/*
+ * Request the Cygnus IOMUX pinmux controller to mux individual pins to GPIO
+ */
+static int cygnus_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned gpio = gc->base + offset;
+
+	/* not all Cygnus GPIO pins can be muxed individually */
+	if (!chip->pinmux_is_supported)
+		return 0;
+
+	return pinctrl_request_gpio(gpio);
+}
+
+static void cygnus_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned gpio = gc->base + offset;
+
+	if (!chip->pinmux_is_supported)
+		return;
+
+	pinctrl_free_gpio(gpio);
+}
+
+static int cygnus_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_set_bit(chip, CYGNUS_GPIO_OUT_EN_OFFSET, gpio, false);
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
+
+	return 0;
+}
+
+static int cygnus_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
+					int val)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_set_bit(chip, CYGNUS_GPIO_OUT_EN_OFFSET, gpio, true);
+	cygnus_set_bit(chip, CYGNUS_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
+
+	return 0;
+}
+
+static void cygnus_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	cygnus_set_bit(chip, CYGNUS_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
+}
+
+static int cygnus_gpio_get(struct gpio_chip *gc, unsigned gpio)
+{
+	struct cygnus_gpio *chip = to_cygnus_gpio(gc);
+	unsigned int offset = CYGNUS_GPIO_REG(gpio,
+					      CYGNUS_GPIO_DATA_IN_OFFSET);
+	unsigned int shift = CYGNUS_GPIO_SHIFT(gpio);
+
+	return !!(readl(chip->base + offset) & BIT(shift));
+}
+
+static int cygnus_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return 1;
+}
+
+/*
+ * Only one group: "gpio_grp", since this local pinctrl device only performs
+ * GPIO specific PINCONF configurations
+ */
+static const char *cygnus_get_group_name(struct pinctrl_dev *pctldev,
+					 unsigned selector)
+{
+	return "gpio_grp";
+}
+
+static const struct pinctrl_ops cygnus_pctrl_ops = {
+	.get_groups_count = cygnus_get_groups_count,
+	.get_group_name = cygnus_get_group_name,
+	.dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+	.dt_free_map = pinctrl_utils_dt_free_map,
+};
+
+static int cygnus_gpio_set_pull(struct cygnus_gpio *chip, unsigned gpio,
+				bool disable, bool pull_up)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+
+	if (disable) {
+		cygnus_set_bit(chip, CYGNUS_GPIO_RES_EN_OFFSET, gpio, false);
+	} else {
+		cygnus_set_bit(chip, CYGNUS_GPIO_PAD_RES_OFFSET, gpio,
+			       pull_up);
+		cygnus_set_bit(chip, CYGNUS_GPIO_RES_EN_OFFSET, gpio, true);
+	}
+
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	dev_dbg(chip->dev, "gpio:%u set pullup:%d\n", gpio, pull_up);
+
+	return 0;
+}
+
+static void cygnus_gpio_get_pull(struct cygnus_gpio *chip, unsigned gpio,
+				 bool *disable, bool *pull_up)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->lock, flags);
+	*disable = !cygnus_get_bit(chip, CYGNUS_GPIO_RES_EN_OFFSET, gpio);
+	*pull_up = cygnus_get_bit(chip, CYGNUS_GPIO_PAD_RES_OFFSET, gpio);
+	spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int cygnus_gpio_set_strength(struct cygnus_gpio *chip, unsigned gpio,
+				    unsigned strength)
+{
+	void __iomem *base;
+	unsigned int i, offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	/* make sure drive strength is supported */
+	if (strength < 2 ||  strength > 16 || (strength % 2))
+		return -ENOTSUPP;
+
+	if (chip->io_ctrl) {
+		base = chip->io_ctrl;
+		offset = CYGNUS_GPIO_DRV0_CTRL_OFFSET;
+	} else {
+		base = chip->base;
+		offset = CYGNUS_GPIO_REG(gpio,
+					 CYGNUS_GPIO_ASIU_DRV0_CTRL_OFFSET);
+	}
+
+	shift = CYGNUS_GPIO_SHIFT(gpio);
+
+	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
+		strength);
+
+	spin_lock_irqsave(&chip->lock, flags);
+	strength = (strength / 2) - 1;
+	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
+		val = readl(base + offset);
+		val &= ~BIT(shift);
+		val |= ((strength >> i) & 0x1) << shift;
+		writel(val, base + offset);
+		offset += 4;
+	}
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
+static int cygnus_gpio_get_strength(struct cygnus_gpio *chip, unsigned gpio,
+				    u16 *strength)
+{
+	void __iomem *base;
+	unsigned int i, offset, shift;
+	u32 val;
+	unsigned long flags;
+
+	if (chip->io_ctrl) {
+		base = chip->io_ctrl;
+		offset = CYGNUS_GPIO_DRV0_CTRL_OFFSET;
+	} else {
+		base = chip->base;
+		offset = CYGNUS_GPIO_REG(gpio,
+					 CYGNUS_GPIO_ASIU_DRV0_CTRL_OFFSET);
+	}
+
+	shift = CYGNUS_GPIO_SHIFT(gpio);
+
+	spin_lock_irqsave(&chip->lock, flags);
+	*strength = 0;
+	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
+		val = readl(base + offset) & BIT(shift);
+		val >>= shift;
+		*strength += (val << i);
+		offset += 4;
+	}
+
+	/* convert to mA */
+	*strength = (*strength + 1) * 2;
+	spin_unlock_irqrestore(&chip->lock, flags);
+
+	return 0;
+}
+
+static int cygnus_pin_config_get(struct pinctrl_dev *pctldev, unsigned pin,
+				 unsigned long *config)
+{
+	struct cygnus_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
+	enum pin_config_param param = pinconf_to_config_param(*config);
+	unsigned gpio = cygnus_pin_to_gpio(pin);
+	u16 arg;
+	bool disable, pull_up;
+	int ret;
+
+	switch (param) {
+	case PIN_CONFIG_BIAS_DISABLE:
+		cygnus_gpio_get_pull(chip, gpio, &disable, &pull_up);
+		if (disable)
+			return 0;
+		else
+			return -EINVAL;
+
+	case PIN_CONFIG_BIAS_PULL_UP:
+		cygnus_gpio_get_pull(chip, gpio, &disable, &pull_up);
+		if (!disable && pull_up)
+			return 0;
+		else
+			return -EINVAL;
+
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		cygnus_gpio_get_pull(chip, gpio, &disable, &pull_up);
+		if (!disable && !pull_up)
+			return 0;
+		else
+			return -EINVAL;
+
+	case PIN_CONFIG_DRIVE_STRENGTH:
+		ret = cygnus_gpio_get_strength(chip, gpio, &arg);
+		if (ret)
+			return ret;
+		else
+			*config = pinconf_to_config_packed(param, arg);
+
+		return 0;
+
+	default:
+		return -ENOTSUPP;
+	}
+
+	return -ENOTSUPP;
+}
+
+static int cygnus_pin_config_set(struct pinctrl_dev *pctldev, unsigned pin,
+				 unsigned long *configs, unsigned num_configs)
+{
+	struct cygnus_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
+	enum pin_config_param param;
+	u16 arg;
+	unsigned i, gpio = cygnus_pin_to_gpio(pin);
+	int ret = -ENOTSUPP;
+
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		arg = pinconf_to_config_argument(configs[i]);
+
+		switch (param) {
+		case PIN_CONFIG_BIAS_DISABLE:
+			ret = cygnus_gpio_set_pull(chip, gpio, true, false);
+			if (ret < 0)
+				goto out;
+			break;
+
+		case PIN_CONFIG_BIAS_PULL_UP:
+			ret = cygnus_gpio_set_pull(chip, gpio, false, true);
+			if (ret < 0)
+				goto out;
+			break;
+
+		case PIN_CONFIG_BIAS_PULL_DOWN:
+			ret = cygnus_gpio_set_pull(chip, gpio, false, false);
+			if (ret < 0)
+				goto out;
+			break;
+
+		case PIN_CONFIG_DRIVE_STRENGTH:
+			ret = cygnus_gpio_set_strength(chip, gpio, arg);
+			if (ret < 0)
+				goto out;
+			break;
+
+		default:
+			dev_err(chip->dev, "invalid configuration\n");
+			return -ENOTSUPP;
+		}
+	} /* for each config */
+
+out:
+	return ret;
+}
+
+static const struct pinconf_ops cygnus_pconf_ops = {
+	.is_generic = true,
+	.pin_config_get = cygnus_pin_config_get,
+	.pin_config_set = cygnus_pin_config_set,
+};
+
+/*
+ * Map a GPIO in the local gpio_chip pin space to a pin in the Cygnus IOMUX
+ * pinctrl pin space
+ */
+struct cygnus_gpio_pin_range {
+	unsigned offset;
+	unsigned pin_base;
+	unsigned num_pins;
+};
+
+#define CYGNUS_PINRANGE(o, p, n) { .offset = o, .pin_base = p, .num_pins = n }
+
+/*
+ * Pin mapping table for mapping local GPIO pins to Cygnus IOMUX pinctrl pins
+ */
+static const struct cygnus_gpio_pin_range cygnus_gpio_pintable[] = {
+	CYGNUS_PINRANGE(0, 42, 1),
+	CYGNUS_PINRANGE(1, 44, 3),
+	CYGNUS_PINRANGE(4, 48, 1),
+	CYGNUS_PINRANGE(5, 50, 3),
+	CYGNUS_PINRANGE(8, 126, 1),
+	CYGNUS_PINRANGE(9, 155, 1),
+	CYGNUS_PINRANGE(10, 152, 1),
+	CYGNUS_PINRANGE(11, 154, 1),
+	CYGNUS_PINRANGE(12, 153, 1),
+	CYGNUS_PINRANGE(13, 127, 3),
+	CYGNUS_PINRANGE(16, 140, 1),
+	CYGNUS_PINRANGE(17, 145, 7),
+	CYGNUS_PINRANGE(24, 130, 10),
+	CYGNUS_PINRANGE(34, 141, 4),
+	CYGNUS_PINRANGE(38, 54, 1),
+	CYGNUS_PINRANGE(39, 56, 3),
+	CYGNUS_PINRANGE(42, 60, 3),
+	CYGNUS_PINRANGE(45, 64, 3),
+	CYGNUS_PINRANGE(48, 68, 2),
+	CYGNUS_PINRANGE(50, 84, 6),
+	CYGNUS_PINRANGE(56, 94, 6),
+	CYGNUS_PINRANGE(62, 72, 1),
+	CYGNUS_PINRANGE(63, 70, 1),
+	CYGNUS_PINRANGE(64, 80, 1),
+	CYGNUS_PINRANGE(65, 74, 3),
+	CYGNUS_PINRANGE(68, 78, 1),
+	CYGNUS_PINRANGE(69, 82, 1),
+	CYGNUS_PINRANGE(70, 156, 17),
+	CYGNUS_PINRANGE(87, 104, 12),
+	CYGNUS_PINRANGE(99, 102, 2),
+	CYGNUS_PINRANGE(101, 90, 4),
+	CYGNUS_PINRANGE(105, 116, 10),
+	CYGNUS_PINRANGE(123, 11, 1),
+	CYGNUS_PINRANGE(124, 38, 4),
+	CYGNUS_PINRANGE(128, 43, 1),
+	CYGNUS_PINRANGE(129, 47, 1),
+	CYGNUS_PINRANGE(130, 49, 1),
+	CYGNUS_PINRANGE(131, 53, 1),
+	CYGNUS_PINRANGE(132, 55, 1),
+	CYGNUS_PINRANGE(133, 59, 1),
+	CYGNUS_PINRANGE(134, 63, 1),
+	CYGNUS_PINRANGE(135, 67, 1),
+	CYGNUS_PINRANGE(136, 71, 1),
+	CYGNUS_PINRANGE(137, 73, 1),
+	CYGNUS_PINRANGE(138, 77, 1),
+	CYGNUS_PINRANGE(139, 79, 1),
+	CYGNUS_PINRANGE(140, 81, 1),
+	CYGNUS_PINRANGE(141, 83, 1),
+	CYGNUS_PINRANGE(142, 10, 1)
+};
+
+/*
+ * The Cygnus IOMUX controller mainly supports group based mux configuration,
+ * but certain pins can be muxed to GPIO individually. Only the ASIU GPIO
+ * controller can support this, so it's an optional configuration
+ *
+ * Return -ENODEV means no support and that's fine
+ */
+static int cygnus_gpio_pinmux_add_range(struct cygnus_gpio *chip)
+{
+	struct device_node *node = chip->dev->of_node;
+	struct device_node *pinmux_node;
+	struct platform_device *pinmux_pdev;
+	struct gpio_chip *gc = &chip->gc;
+	int i, ret = 0;
+
+	/* parse DT to find the phandle to the pinmux controller */
+	pinmux_node = of_parse_phandle(node, "pinmux", 0);
+	if (!pinmux_node)
+		return -ENODEV;
+
+	pinmux_pdev = of_find_device_by_node(pinmux_node);
+	/* no longer need the pinmux node */
+	of_node_put(pinmux_node);
+	if (!pinmux_pdev) {
+		dev_err(chip->dev, "failed to get pinmux device\n");
+		return -EINVAL;
+	}
+
+	/* now need to create the mapping between local GPIO and PINMUX pins */
+	for (i = 0; i < ARRAY_SIZE(cygnus_gpio_pintable); i++) {
+		ret = gpiochip_add_pin_range(gc, dev_name(&pinmux_pdev->dev),
+					     cygnus_gpio_pintable[i].offset,
+					     cygnus_gpio_pintable[i].pin_base,
+					     cygnus_gpio_pintable[i].num_pins);
+		if (ret) {
+			dev_err(chip->dev, "unable to add GPIO pin range\n");
+			goto err_put_device;
+		}
+	}
+
+	chip->pinmux_is_supported = true;
+
+	/* no need for pinmux_pdev device reference anymore */
+	put_device(&pinmux_pdev->dev);
+	return 0;
+
+err_put_device:
+	put_device(&pinmux_pdev->dev);
+	gpiochip_remove_pin_ranges(gc);
+	return ret;
+}
+
+/*
+ * Cygnus GPIO controller supports some PINCONF related configurations such as
+ * pull up, pull down, and drive strength, when the pin is configured to GPIO
+ *
+ * Here a local pinctrl device is created with simple 1-to-1 pin mapping to the
+ * local GPIO pins
+ */
+static int cygnus_gpio_register_pinconf(struct cygnus_gpio *chip)
+{
+	struct pinctrl_desc *pctldesc = &chip->pctldesc;
+	struct pinctrl_pin_desc *pins;
+	struct gpio_chip *gc = &chip->gc;
+	int i;
+
+	pins = devm_kcalloc(chip->dev, gc->ngpio, sizeof(*pins), GFP_KERNEL);
+	if (!pins)
+		return -ENOMEM;
+
+	for (i = 0; i < gc->ngpio; i++) {
+		pins[i].number = i;
+		pins[i].name = devm_kasprintf(chip->dev, GFP_KERNEL,
+					      "gpio-%d", i);
+		if (!pins[i].name)
+			return -ENOMEM;
+	}
+
+	pctldesc->name = dev_name(chip->dev);
+	pctldesc->pctlops = &cygnus_pctrl_ops;
+	pctldesc->pins = pins;
+	pctldesc->npins = gc->ngpio;
+	pctldesc->confops = &cygnus_pconf_ops;
+
+	chip->pctl = pinctrl_register(pctldesc, chip->dev, chip);
+	if (!chip->pctl) {
+		dev_err(chip->dev, "unable to register pinctrl device\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void cygnus_gpio_unregister_pinconf(struct cygnus_gpio *chip)
+{
+	if (chip->pctl)
+		pinctrl_unregister(chip->pctl);
+}
+
+static const struct of_device_id cygnus_gpio_of_match[] = {
+	{ .compatible = "brcm,cygnus-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, cygnus_gpio_of_match);
+
+static int cygnus_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct cygnus_gpio *chip;
+	struct gpio_chip *gc;
+	u32 ngpios;
+	int irq, ret;
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = dev;
+	platform_set_drvdata(pdev, chip);
+
+	if (of_property_read_u32(dev->of_node, "ngpios", &ngpios)) {
+		dev_err(dev, "missing ngpios DT property\n");
+		return -ENODEV;
+	}
+	chip->num_banks = (ngpios + NGPIOS_PER_BANK - 1) / NGPIOS_PER_BANK;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	chip->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(chip->base)) {
+		dev_err(dev, "unable to map I/O memory\n");
+		return PTR_ERR(chip->base);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res) {
+		chip->io_ctrl = devm_ioremap_resource(dev, res);
+		if (IS_ERR(chip->io_ctrl)) {
+			dev_err(dev, "unable to map I/O memory\n");
+			return PTR_ERR(chip->io_ctrl);
+		}
+	}
+
+	spin_lock_init(&chip->lock);
+
+	gc = &chip->gc;
+	gc->base = -1;
+	gc->ngpio = ngpios;
+	gc->label = dev_name(dev);
+	gc->dev = dev;
+	gc->of_node = dev->of_node;
+	gc->request = cygnus_gpio_request;
+	gc->free = cygnus_gpio_free;
+	gc->direction_input = cygnus_gpio_direction_input;
+	gc->direction_output = cygnus_gpio_direction_output;
+	gc->set = cygnus_gpio_set;
+	gc->get = cygnus_gpio_get;
+
+	ret = gpiochip_add(gc);
+	if (ret < 0) {
+		dev_err(dev, "unable to add GPIO chip\n");
+		return ret;
+	}
+
+	ret = cygnus_gpio_pinmux_add_range(chip);
+	if (ret && ret != -ENODEV) {
+		dev_err(dev, "unable to add GPIO pin range\n");
+		goto err_rm_gpiochip;
+	}
+
+	ret = cygnus_gpio_register_pinconf(chip);
+	if (ret) {
+		dev_err(dev, "unable to register pinconf\n");
+		goto err_rm_gpiochip;
+	}
+
+	/* optional GPIO interrupt support */
+	irq = platform_get_irq(pdev, 0);
+	if (irq) {
+		ret = gpiochip_irqchip_add(gc, &cygnus_gpio_irq_chip, 0,
+					   handle_simple_irq, IRQ_TYPE_NONE);
+		if (ret) {
+			dev_err(dev, "no GPIO irqchip\n");
+			goto err_unregister_pinconf;
+		}
+
+		gpiochip_set_chained_irqchip(gc, &cygnus_gpio_irq_chip, irq,
+					     cygnus_gpio_irq_handler);
+	}
+
+	return 0;
+
+err_unregister_pinconf:
+	cygnus_gpio_unregister_pinconf(chip);
+
+err_rm_gpiochip:
+	gpiochip_remove(gc);
+
+	return ret;
+}
+
+static struct platform_driver cygnus_gpio_driver = {
+	.driver = {
+		.name = "cygnus-gpio",
+		.of_match_table = cygnus_gpio_of_match,
+	},
+	.probe = cygnus_gpio_probe,
+};
+
+static int __init cygnus_gpio_init(void)
+{
+	return platform_driver_probe(&cygnus_gpio_driver, cygnus_gpio_probe);
+}
+arch_initcall_sync(cygnus_gpio_init);
+
+MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Cygnus GPIO Driver");
+MODULE_LICENSE("GPL v2");