diff mbox

[v7] gpio: add Intel WhiskeyCove PMIC GPIO driver

Message ID 20160725215938.GC211765@worksta
State New
Headers show

Commit Message

Bin Gao July 25, 2016, 9:59 p.m. UTC
This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
This driver is based on gpio-crystalcove.c.

Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
Signed-off-by: Bin Gao <bin.gao@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
Changes in v7:
 - Fixed various coding style comments from Andy Shevchenko
Changes in v6:
 - Removed unnecessary wcove_gpio_remove()
 - Used devm_gpiochip_remove() instead of gpiochip_remove()
 - Various coding style changes per Mika's comment
Changes in v5:
 - Revisited the interrupt handler code to iterate until all pending
   interrupts are handled. This change is to avoid missing interrupt
   when we're inside the interrupt handler.
 - Used regmap_bulk_read() to read address adjacent registers.
Changes in v4:
 - Converted CTLI_INTCNT_XX macros to less verbose ones INT_DETECT_XX.
 - Add comments about why there is no .pm for the driver.
 - Header files re-ordered.
 - Various coding style change to address Andy's comments.
Changes in v3:
 - Fixed the year in copyright line(2015-->2016).
 - Removed DRV_NAME macro.
 - Added kernel-doc for regmap_irq_chip of the wcove_gpio structure.
 - Line length fix.
Changes in v2:
 - Typo fix (Whsikey --> Whiskey).
 - Included linux/gpio/driver.h instead of linux/gpio.h
 - Implemented .set_single_ended().
 - Added GPIO register description.
 - Replaced container_of() with gpiochip_get_data().
 - Removed unnecessary "if (gpio > WCOVE_VGPIO_NUM" check.
 - Removed the device id table and added MODULE_ALIAS().
 drivers/gpio/Kconfig      |  13 ++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/gpio-wcove.c | 455 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 469 insertions(+)
 create mode 100644 drivers/gpio/gpio-wcove.c

Comments

Linus Walleij Aug. 11, 2016, 11:30 a.m. UTC | #1
On Mon, Jul 25, 2016 at 11:59 PM, Bin Gao <bin.gao@linux.intel.com> wrote:

> This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
> This driver is based on gpio-crystalcove.c.
>
> Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
> Signed-off-by: Bin Gao <bin.gao@intel.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
> Changes in v7:

This v7 patch applied.

Can you please send a separate patch adding .get_direction() to the
gpiochip? It's a feature I've been pushing more and more recently.

Yours,
Linus Walleij
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Paul Gortmaker Sept. 12, 2016, 10:37 p.m. UTC | #2
On Mon, Jul 25, 2016 at 5:59 PM, Bin Gao <bin.gao@linux.intel.com> wrote:
> This patch introduces a separate GPIO driver for Intel WhiskeyCove PMIC.
> This driver is based on gpio-crystalcove.c.
>
> Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>

This looks like an invalid address, and ....

> Signed-off-by: Bin Gao <bin.gao@intel.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---

[....]

> +module_platform_driver(wcove_gpio_driver);
> +
> +MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");

...the same here.  In fact it sure looks like two names.  Anyway I just got a
bounce when I tried to use it...

Paul.
--

> +MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
> +MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:bxt_wcove_gpio");
> --
> 1.9.1
>
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Andy Shevchenko Sept. 13, 2016, 7:02 a.m. UTC | #3
On Tue, Sep 13, 2016 at 1:37 AM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
>> Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
>
> This looks like an invalid address, and ....

>> +MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
>
> ...the same here.  In fact it sure looks like two names.  Anyway I just got a
> bounce when I tried to use it...

It might be that person is no longer working for Intel, though I think
It would be better log message for that.
Paul Gortmaker Sept. 13, 2016, 1:37 p.m. UTC | #4
[Re: [PATCH v7] gpio: add Intel WhiskeyCove PMIC GPIO driver] On 13/09/2016 (Tue 10:02) Andy Shevchenko wrote:

> On Tue, Sep 13, 2016 at 1:37 AM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> >> Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
> >
> > This looks like an invalid address, and ....
> 
> >> +MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
> >
> > ...the same here.  In fact it sure looks like two names.  Anyway I just got a
> > bounce when I tried to use it...
> 
> It might be that person is no longer working for Intel, though I think
> It would be better log message for that.

That might make sense if the driver was old, but it hasn't even hit
mainline yet -- it is only in linux-next, so it cant be more than a few
weeks old.

P.
--

> 
> -- 
> With Best Regards,
> Andy Shevchenko
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Andy Shevchenko Sept. 13, 2016, 2:35 p.m. UTC | #5
On Tue, Sep 13, 2016 at 4:37 PM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
>> > This looks like an invalid address, and ....
>>
>> >> +MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
>> >
>> > ...the same here.  In fact it sure looks like two names.  Anyway I just got a
>> > bounce when I tried to use it...
>>
>> It might be that person is no longer working for Intel, though I think
>> It would be better log message for that.
>
> That might make sense if the driver was old, but it hasn't even hit
> mainline yet -- it is only in linux-next, so it cant be more than a few
> weeks old.

It's already quite off topic, so, I would just say that it is still
valid point. Starting from some version of the series (which takes
couple of months?) Bin Gao did improvements.
Paul Gortmaker Sept. 13, 2016, 2:46 p.m. UTC | #6
[Re: [PATCH v7] gpio: add Intel WhiskeyCove PMIC GPIO driver] On 13/09/2016 (Tue 17:35) Andy Shevchenko wrote:

> On Tue, Sep 13, 2016 at 4:37 PM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> >> > This looks like an invalid address, and ....
> >>
> >> >> +MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
> >> >
> >> > ...the same here.  In fact it sure looks like two names.  Anyway I just got a
> >> > bounce when I tried to use it...
> >>
> >> It might be that person is no longer working for Intel, though I think
> >> It would be better log message for that.
> >
> > That might make sense if the driver was old, but it hasn't even hit
> > mainline yet -- it is only in linux-next, so it cant be more than a few
> > weeks old.
> 
> It's already quite off topic, so, I would just say that it is still
> valid point. Starting from some version of the series (which takes
> couple of months?) Bin Gao did improvements.

Not sure why you would call it off topic -- a new driver appearing in
mainline should have a valid author entry, and if it is an accidental
merge of two names into one then Bin Gao is the person who can ack that
and subsequently fix it.

P.
--

> 
> -- 
> With Best Regards,
> Andy Shevchenko
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Gao, Bin Sept. 13, 2016, 3:49 p.m. UTC | #7
On Fri, Sep 13, 2016 at 07:46:31AM, Paul Gortmaker wrote:
>> On Tue, Sep 13, 2016 at 4:37 PM, Paul Gortmaker 
>> <paul.gortmaker@windriver.com> wrote:
>> >> > This looks like an invalid address, and ....
>> >>
>> >> >> +MODULE_AUTHOR("Ajay Thomas 
>> >> >> +<ajay.thomas.david.rajamanickam@intel.com>");
>> >> >
>> >> > ...the same here.  In fact it sure looks like two names.  Anyway 
>> >> > I just got a bounce when I tried to use it...
>> >>
>> >> It might be that person is no longer working for Intel, though I 
>> >> think It would be better log message for that.
>> >
>> > That might make sense if the driver was old, but it hasn't even hit 
>> > mainline yet -- it is only in linux-next, so it cant be more than a 
>> > few weeks old.
>> 
>> It's already quite off topic, so, I would just say that it is still 
>> valid point. Starting from some version of the series (which takes 
>> couple of months?) Bin Gao did improvements.
>
>Not sure why you would call it off topic -- a new driver appearing in mainline should have a valid author entry, and if it is an accidental merge of two names into one then Bin Gao is the person who can ack that and subsequently fix it.
>
>P.

The original email is correct and it's not an accidental merge of two names.
The cause is Ajay quitted Intel one month back so his email address is no longer valid. 

-Bin
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diff mbox

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 536112f..240ae7c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -972,6 +972,19 @@  config GPIO_UCB1400
 	  This enables support for the Philips UCB1400 GPIO pins.
 	  The UCB1400 is an AC97 audio codec.
 
+config GPIO_WHISKEY_COVE
+	tristate "GPIO support for Whiskey Cove PMIC"
+	depends on INTEL_SOC_PMIC
+	select GPIOLIB_IRQCHIP
+	help
+	  Support for GPIO pins on Whiskey Cove PMIC.
+
+	  Say Yes if you have a Intel SoC based tablet with Whiskey Cove PMIC
+	  inside.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called gpio-wcove.
+
 config GPIO_WM831X
 	tristate "WM831x GPIOs"
 	depends on MFD_WM831X
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 991598e..fff27b0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -118,6 +118,7 @@  obj-$(CONFIG_GPIO_VF610)	+= gpio-vf610.o
 obj-$(CONFIG_GPIO_VIPERBOARD)	+= gpio-viperboard.o
 obj-$(CONFIG_GPIO_VR41XX)	+= gpio-vr41xx.o
 obj-$(CONFIG_GPIO_VX855)	+= gpio-vx855.o
+obj-$(CONFIG_GPIO_WHISKEY_COVE)	+= gpio-wcove.o
 obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
 obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
 obj-$(CONFIG_GPIO_WM8994)	+= gpio-wm8994.o
diff --git a/drivers/gpio/gpio-wcove.c b/drivers/gpio/gpio-wcove.c
new file mode 100644
index 0000000..f5c88df
--- /dev/null
+++ b/drivers/gpio/gpio-wcove.c
@@ -0,0 +1,455 @@ 
+/*
+ * Intel Whiskey Cove PMIC GPIO Driver
+ *
+ * This driver is written based on gpio-crystalcove.c
+ *
+ * Copyright (C) 2016 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/driver.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/seq_file.h>
+
+/*
+ * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
+ * Bank 0: Pin 0 - 6
+ * Bank 1: Pin 7 - 10
+ * Bank 2: Pin 11 -12
+ * Each pin has one output control register and one input control register.
+ */
+#define BANK0_NR_PINS		7
+#define BANK1_NR_PINS		4
+#define BANK2_NR_PINS		2
+#define WCOVE_GPIO_NUM		(BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
+#define WCOVE_VGPIO_NUM		94
+/* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
+#define GPIO_OUT_CTRL_BASE	0x4e44
+/* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
+#define GPIO_IN_CTRL_BASE	0x4e51
+
+/*
+ * GPIO interrupts are organized in two groups:
+ * Group 0: Bank 0 pins (Pin 0 - 6)
+ * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
+ * Each group has two registers (one bit per pin): status and mask.
+ */
+#define GROUP0_NR_IRQS		7
+#define GROUP1_NR_IRQS		6
+#define IRQ_MASK_BASE		0x4e19
+#define IRQ_STATUS_BASE		0x4e0b
+#define UPDATE_IRQ_TYPE		BIT(0)
+#define UPDATE_IRQ_MASK		BIT(1)
+
+#define CTLI_INTCNT_DIS		(0 << 1)
+#define CTLI_INTCNT_NE		(1 << 1)
+#define CTLI_INTCNT_PE		(2 << 1)
+#define CTLI_INTCNT_BE		(3 << 1)
+
+#define CTLO_DIR_IN		(0 << 5)
+#define CTLO_DIR_OUT		(1 << 5)
+
+#define CTLO_DRV_MASK		(1 << 4)
+#define CTLO_DRV_OD		(0 << 4)
+#define CTLO_DRV_CMOS		(1 << 4)
+
+#define CTLO_DRV_REN		(1 << 3)
+
+#define CTLO_RVAL_2KDOWN	(0 << 1)
+#define CTLO_RVAL_2KUP		(1 << 1)
+#define CTLO_RVAL_50KDOWN	(2 << 1)
+#define CTLO_RVAL_50KUP		(3 << 1)
+
+#define CTLO_INPUT_SET	(CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
+#define CTLO_OUTPUT_SET	(CTLO_DIR_OUT | CTLO_INPUT_SET)
+
+enum ctrl_register {
+	CTRL_IN,
+	CTRL_OUT,
+};
+
+/*
+ * struct wcove_gpio - Whiskey Cove GPIO controller
+ * @buslock: for bus lock/sync and unlock.
+ * @chip: the abstract gpio_chip structure.
+ * @dev: the gpio device
+ * @regmap: the regmap from the parent device.
+ * @regmap_irq_chip: the regmap of the gpio irq chip.
+ * @update: pending IRQ setting update, to be written to the chip upon unlock.
+ * @intcnt: the Interrupt Detect value to be written.
+ * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
+ */
+struct wcove_gpio {
+	struct mutex buslock;
+	struct gpio_chip chip;
+	struct device *dev;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *regmap_irq_chip;
+	int update;
+	int intcnt;
+	bool set_irq_mask;
+};
+
+static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
+{
+	unsigned int reg;
+	int bank;
+
+	if (gpio < BANK0_NR_PINS)
+		bank = 0;
+	else if (gpio < BANK0_NR_PINS + BANK1_NR_PINS)
+		bank = 1;
+	else
+		bank = 2;
+
+	if (reg_type == CTRL_IN)
+		reg = GPIO_IN_CTRL_BASE + bank;
+	else
+		reg = GPIO_OUT_CTRL_BASE + bank;
+
+	return reg;
+}
+
+static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
+{
+	unsigned int reg, mask;
+
+	if (gpio < GROUP0_NR_IRQS) {
+		reg = IRQ_MASK_BASE;
+		mask = BIT(gpio % GROUP0_NR_IRQS);
+	} else {
+		reg = IRQ_MASK_BASE + 1;
+		mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
+	}
+
+	if (wg->set_irq_mask)
+		regmap_update_bits(wg->regmap, reg, mask, mask);
+	else
+		regmap_update_bits(wg->regmap, reg, mask, 0);
+}
+
+static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
+{
+	unsigned int reg = to_reg(gpio, CTRL_IN);
+
+	regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
+}
+
+static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
+			    CTLO_INPUT_SET);
+}
+
+static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
+				    int value)
+{
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	return regmap_write(wg->regmap, to_reg(gpio, CTRL_OUT),
+			    CTLO_OUTPUT_SET | value);
+}
+
+static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &val);
+	if (ret)
+		return ret;
+
+	return val & 0x1;
+}
+
+static void wcove_gpio_set(struct gpio_chip *chip,
+				 unsigned int gpio, int value)
+{
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	if (value)
+		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 1);
+	else
+		regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT), 1, 0);
+}
+
+static int wcove_gpio_set_single_ended(struct gpio_chip *chip,
+					unsigned int gpio,
+					enum single_ended_mode mode)
+{
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	switch (mode) {
+	case LINE_MODE_OPEN_DRAIN:
+		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
+						CTLO_DRV_MASK, CTLO_DRV_OD);
+	case LINE_MODE_PUSH_PULL:
+		return regmap_update_bits(wg->regmap, to_reg(gpio, CTRL_OUT),
+						CTLO_DRV_MASK, CTLO_DRV_CMOS);
+	default:
+		break;
+	}
+
+	return -ENOTSUPP;
+}
+
+static int wcove_irq_type(struct irq_data *data, unsigned int type)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		wg->intcnt = CTLI_INTCNT_DIS;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		wg->intcnt = CTLI_INTCNT_BE;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		wg->intcnt = CTLI_INTCNT_PE;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		wg->intcnt = CTLI_INTCNT_NE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	wg->update |= UPDATE_IRQ_TYPE;
+
+	return 0;
+}
+
+static void wcove_bus_lock(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	mutex_lock(&wg->buslock);
+}
+
+static void wcove_bus_sync_unlock(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+	int gpio = data->hwirq;
+
+	if (wg->update & UPDATE_IRQ_TYPE)
+		wcove_update_irq_ctrl(wg, gpio);
+	if (wg->update & UPDATE_IRQ_MASK)
+		wcove_update_irq_mask(wg, gpio);
+	wg->update = 0;
+
+	mutex_unlock(&wg->buslock);
+}
+
+static void wcove_irq_unmask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	wg->set_irq_mask = false;
+	wg->update |= UPDATE_IRQ_MASK;
+}
+
+static void wcove_irq_mask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+
+	wg->set_irq_mask = true;
+	wg->update |= UPDATE_IRQ_MASK;
+}
+
+static struct irq_chip wcove_irqchip = {
+	.name			= "Whiskey Cove",
+	.irq_mask		= wcove_irq_mask,
+	.irq_unmask		= wcove_irq_unmask,
+	.irq_set_type		= wcove_irq_type,
+	.irq_bus_lock		= wcove_bus_lock,
+	.irq_bus_sync_unlock	= wcove_bus_sync_unlock,
+};
+
+static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
+{
+	struct wcove_gpio *wg = (struct wcove_gpio *)data;
+	unsigned int pending, virq, gpio, mask, offset;
+	u8 p[2];
+
+	if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
+		dev_err(wg->dev, "Failed to read irq status register\n");
+		return IRQ_NONE;
+	}
+
+	pending = p[0] | (p[1] << 8);
+	if (!pending)
+		return IRQ_NONE;
+
+	/* Iterate until no interrupt is pending */
+	while (pending) {
+		/* One iteration is for all pending bits */
+		for_each_set_bit(gpio, (const unsigned long *)&pending,
+						 GROUP0_NR_IRQS) {
+			offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
+			mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
+								BIT(gpio);
+			virq = irq_find_mapping(wg->chip.irqdomain, gpio);
+			handle_nested_irq(virq);
+			regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
+								mask, mask);
+		}
+
+		/* Next iteration */
+		if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
+			dev_err(wg->dev, "Failed to read irq status\n");
+			break;
+		}
+
+		pending = p[0] | (p[1] << 8);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void wcove_gpio_dbg_show(struct seq_file *s,
+				      struct gpio_chip *chip)
+{
+	unsigned int ctlo, ctli, irq_mask, irq_status;
+	struct wcove_gpio *wg = gpiochip_get_data(chip);
+	int gpio, offset, group, ret = 0;
+
+	for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
+		group = gpio < GROUP0_NR_IRQS ? 0 : 1;
+		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
+		ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
+		ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
+							&irq_mask);
+		ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
+							&irq_status);
+		if (ret) {
+			pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
+			break;
+		}
+
+		offset = gpio % 8;
+		seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
+			   gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
+			   ctli & 0x1 ? "hi" : "lo",
+			   ctli & CTLI_INTCNT_NE ? "fall" : "    ",
+			   ctli & CTLI_INTCNT_PE ? "rise" : "    ",
+			   ctlo,
+			   irq_mask & BIT(offset) ? "mask  " : "unmask",
+			   irq_status & BIT(offset) ? "pending" : "       ");
+	}
+}
+
+static int wcove_gpio_probe(struct platform_device *pdev)
+{
+	struct intel_soc_pmic *pmic;
+	struct wcove_gpio *wg;
+	int virq, ret, irq;
+	struct device *dev;
+
+	/*
+	 * This gpio platform device is created by a mfd device (see
+	 * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
+	 * shared by all sub-devices created by the mfd device, the regmap
+	 * pointer for instance, is stored as driver data of the mfd device
+	 * driver.
+	 */
+	pmic = dev_get_drvdata(pdev->dev.parent);
+	if (!pmic)
+		return -ENODEV;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	dev = &pdev->dev;
+
+	wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
+	if (!wg)
+		return -ENOMEM;
+
+	wg->regmap_irq_chip = pmic->irq_chip_data_level2;
+
+	platform_set_drvdata(pdev, wg);
+
+	mutex_init(&wg->buslock);
+	wg->chip.label = KBUILD_MODNAME;
+	wg->chip.direction_input = wcove_gpio_dir_in;
+	wg->chip.direction_output = wcove_gpio_dir_out;
+	wg->chip.get = wcove_gpio_get;
+	wg->chip.set = wcove_gpio_set;
+	wg->chip.set_single_ended = wcove_gpio_set_single_ended,
+	wg->chip.base = -1;
+	wg->chip.ngpio = WCOVE_VGPIO_NUM;
+	wg->chip.can_sleep = true;
+	wg->chip.parent = pdev->dev.parent;
+	wg->chip.dbg_show = wcove_gpio_dbg_show;
+	wg->dev = dev;
+	wg->regmap = pmic->regmap;
+
+	ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
+	if (ret) {
+		dev_err(dev, "Failed to add gpiochip: %d\n", ret);
+		return ret;
+	}
+
+	ret = gpiochip_irqchip_add(&wg->chip, &wcove_irqchip, 0,
+			     handle_simple_irq, IRQ_TYPE_NONE);
+	if (ret) {
+		dev_err(dev, "Failed to add irqchip: %d\n", ret);
+		return ret;
+	}
+
+	virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
+	if (virq < 0) {
+		dev_err(dev, "Failed to get virq by irq %d\n", irq);
+		return virq;
+	}
+
+	ret = devm_request_threaded_irq(dev, virq, NULL,
+		wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
+	if (ret) {
+		dev_err(dev, "Failed to request irq %d\n", virq);
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * Whiskey Cove PMIC itself is a analog device(but with digital control
+ * interface) providing power management support for other devices in
+ * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
+ */
+static struct platform_driver wcove_gpio_driver = {
+	.driver = {
+		.name = "bxt_wcove_gpio",
+	},
+	.probe = wcove_gpio_probe,
+};
+
+module_platform_driver(wcove_gpio_driver);
+
+MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
+MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
+MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:bxt_wcove_gpio");