diff mbox

[RFC/PATCH,4/4] gpio: smscece: Add support for gpio IO expander feature

Message ID 1345545940-2232-5-git-send-email-sourav.poddar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Poddar, Sourav Aug. 21, 2012, 10:45 a.m. UTC
smsc can be used as an gpio io expander device also. So adding
support for configuring smsc pins as a gpio.

Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
---
 drivers/gpio/Kconfig        |    7 +
 drivers/gpio/Makefile       |    1 +
 drivers/gpio/gpio-smscece.c |  373 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 381 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/gpio-smscece.c

Comments

Felipe Balbi Aug. 21, 2012, 10:53 a.m. UTC | #1
Hi,

On Tue, Aug 21, 2012 at 04:15:40PM +0530, Sourav Poddar wrote:
> smsc can be used as an gpio io expander device also. So adding
> support for configuring smsc pins as a gpio.
> 
> Cc: Benoit Cousson <b-cousson@ti.com>
> Cc: Felipe Balbi <balbi@ti.com>
> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
> ---
>  drivers/gpio/Kconfig        |    7 +
>  drivers/gpio/Makefile       |    1 +
>  drivers/gpio/gpio-smscece.c |  373 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 381 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/gpio/gpio-smscece.c
> 
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b16c8a7..e883929 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -444,6 +444,13 @@ config GPIO_ADP5588_IRQ
>  	  Say yes here to enable the adp5588 to be used as an interrupt
>  	  controller. It requires the driver to be built in the kernel.
>  
> +config GPIO_SMSCECE
> +	tristate "SMSCECE 1099 I2C GPIO expander"
> +	depends on I2C
> +	help
> +	  This option enables support for 18 GPIOs found
> +	  on SMSC ECE 1099 GPIO Expanders.
> +
>  comment "PCI GPIO expanders:"
>  
>  config GPIO_CS5535
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 153cace..7c803c5 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_74X164)	+= gpio-74x164.o
>  obj-$(CONFIG_GPIO_AB8500)	+= gpio-ab8500.o
>  obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
>  obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
> +obj-$(CONFIG_GPIO_SMSCECE)      += gpio-smscece.o
>  obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
>  obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
>  obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
> diff --git a/drivers/gpio/gpio-smscece.c b/drivers/gpio/gpio-smscece.c
> new file mode 100644
> index 0000000..0cb0959
> --- /dev/null
> +++ b/drivers/gpio/gpio-smscece.c
> @@ -0,0 +1,373 @@
> +/*
> + * GPIO Chip driver for smsc
> + * SMSC I/O Expander and QWERTY Keypad Controller
> + *
> + * Copyright 2012 Texas Instruments Inc.
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/gpio.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqdomain.h>
> +#include <linux/irq.h>
> +#include <linux/mfd/smsc.h>
> +#include <linux/err.h>
> +
> +struct smsc_gpio {
> +	struct device *dev;
> +	struct smsc *smsc;
> +	struct gpio_chip gpio_chip;
> +	struct mutex lock;	/* protect cached dir, dat_out */
> +	/* protect serialized access to the interrupt controller bus */
> +	struct mutex irq_lock;
> +	unsigned gpio_start;
> +	int type;
> +	int flags;
> +	int irq;
> +	int irq_base;
> +	unsigned int gpio_base;
> +	unsigned int dat_out[5];
> +	unsigned int dir[5];
> +	unsigned int int_lvl[5];
> +	unsigned int int_en[5];
> +	unsigned int irq_mask[5];
> +	unsigned int irq_stat[5];
> +};
> +
> +static int smsc_gpio_get_value(struct gpio_chip *chip, unsigned off)
> +{
> +	struct smsc_gpio *sg =
> +		container_of(chip, struct smsc_gpio, gpio_chip);
> +	unsigned int get;
> +	return !!(smsc_read(sg->dev,
> +		(SMSC_GPIO_DATA_IN_START + SMSC_BANK(off)) & SMSC_BIT(off),
> +					&get));
> +}
> +
> +static void smsc_gpio_set_value(struct gpio_chip *chip,
> +			unsigned off, int val)
> +{
> +	unsigned bank, bit;
> +	struct smsc_gpio *sg =
> +		container_of(chip, struct smsc_gpio, gpio_chip);
> +
> +	bank = SMSC_BANK(off);
> +	bit = SMSC_BIT(off);
> +
> +	mutex_lock(&sg->lock);
> +	if (val)
> +		sg->dat_out[bank] |= bit;
> +	else
> +		sg->dat_out[bank] &= ~bit;
> +
> +	smsc_write(sg->dev, SMSC_GPIO_DATA_OUT_START + bank,
> +			   sg->dat_out[bank]);
> +	mutex_unlock(&sg->lock);
> +}
> +
> +static int smsc_gpio_direction_input(struct gpio_chip *chip, unsigned off)
> +{
> +	unsigned int reg;
> +	struct smsc_gpio *sg =
> +	    container_of(chip, struct smsc_gpio, gpio_chip);
> +	int reg_dir;
> +
> +	mutex_lock(&sg->lock);
> +	reg_dir = SMSC_CFG_START + off;
> +	smsc_read(sg->dev, reg_dir, &reg);
> +	reg |= SMSC_GPIO_INPUT_LOW;
> +	mutex_unlock(&sg->lock);
> +
> +	return smsc_write(sg->dev, reg_dir, reg);
> +}
> +
> +static int smsc_gpio_direction_output(struct gpio_chip *chip,
> +					 unsigned off, int val)
> +{
> +	unsigned int reg;
> +	struct smsc_gpio *sg =
> +	    container_of(chip, struct smsc_gpio, gpio_chip);
> +	int reg_dir;
> +
> +	mutex_lock(&sg->lock);
> +	reg_dir = SMSC_CFG_START + off;
> +	smsc_read(sg->dev, reg_dir, &reg);
> +	reg |= SMSC_GPIO_OUTPUT_PP;
> +	mutex_unlock(&sg->lock);
> +
> +	return smsc_write(sg->dev, reg_dir, reg);
> +}
> +
> +static int smsc_gpio_to_irq(struct gpio_chip *chip, unsigned off)
> +{
> +	struct smsc_gpio *sg =
> +		container_of(chip, struct smsc_gpio, gpio_chip);
> +	return sg->irq_base + off;
> +}
> +
> +static void smsc_irq_bus_lock(struct irq_data *d)
> +{
> +	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
> +
> +	mutex_lock(&sg->irq_lock);
> +}
> +
> +static void smsc_irq_bus_sync_unlock(struct irq_data *d)
> +{
> +	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
> +	int i;
> +
> +	for (i = 0; i < SMSC_BANK(SMSC_MAXGPIO); i++)
> +		if (sg->int_en[i] ^ sg->irq_mask[i]) {
> +			sg->int_en[i] = sg->irq_mask[i];
> +			smsc_write(sg->dev, SMSC_GPIO_INT_MASK_START + i,
> +					   sg->int_en[i]);
> +		}
> +
> +	mutex_unlock(&sg->irq_lock);
> +}
> +
> +static void smsc_irq_mask(struct irq_data *d)
> +{
> +	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
> +	unsigned gpio = d->irq - sg->irq_base;
> +
> +	sg->irq_mask[SMSC_BANK(gpio)] &= ~SMSC_BIT(gpio);
> +}
> +
> +static void smsc_irq_unmask(struct irq_data *d)
> +{
> +	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
> +	unsigned gpio = d->irq - sg->irq_base;
> +
> +	sg->irq_mask[SMSC_BANK(gpio)] |= SMSC_BIT(gpio);
> +}
> +
> +static int smsc_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> +	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
> +	uint16_t gpio = d->irq - sg->irq_base;
> +	unsigned bank, bit;
> +
> +	if ((type & IRQ_TYPE_EDGE_BOTH)) {
> +		dev_err(sg->dev, "irq %d: unsupported type %d\n",
> +			d->irq, type);
> +		return -EINVAL;
> +	}
> +
> +	bank = SMSC_BANK(gpio);
> +	bit = SMSC_BIT(gpio);
> +
> +	if (type & IRQ_TYPE_LEVEL_HIGH)
> +		sg->int_lvl[bank] |= bit;
> +	else if (type & IRQ_TYPE_LEVEL_LOW)
> +		sg->int_lvl[bank] &= ~bit;
> +	else
> +		return -EINVAL;

this looks wrong. You could have a user who wants to trigger on both
HIGH and LOW levels, no ?

> +	smsc_gpio_direction_input(&sg->gpio_chip, gpio);
> +	smsc_write(sg->dev, SMSC_CFG_START + gpio,
> +			sg->int_lvl[bank]);
> +
> +	return 0;
> +}
> +
> +static struct irq_chip smsc_irq_chip = {
> +	.name			= "smsc",
> +	.irq_mask		= smsc_irq_mask,
> +	.irq_unmask		= smsc_irq_unmask,
> +	.irq_bus_lock		= smsc_irq_bus_lock,
> +	.irq_bus_sync_unlock	= smsc_irq_bus_sync_unlock,
> +	.irq_set_type		= smsc_irq_set_type,
> +};
> +
> +static int smsc_gpio_read_intstat(struct smsc_gpio *sg,
> +				unsigned int *buf, int i)
> +{
> +	int ret = smsc_read(sg->dev,
> +			SMSC_GPIO_INT_STAT_START + i, buf);
> +
> +	if (ret < 0)
> +		dev_err(sg->dev, "Read INT_STAT Error\n");
> +
> +	return ret;
> +}
> +
> +static irqreturn_t smsc_irq_handler(int irq, void *devid)
> +{
> +	struct smsc_gpio *sg = devid;
> +	unsigned int status, bank, pending;
> +	int ret;
> +	smsc_read(sg->dev, GRP_INT_STAT, &status);
> +
> +	if (!(status & SMSC_GPI_INT))
> +		goto out;
> +
> +	for (bank = 0; bank <= SMSC_BANK(SMSC_MAXGPIO);
> +		bank++) {
> +		pending = sg->irq_stat[bank] & sg->irq_mask[bank];
> +		ret = smsc_gpio_read_intstat(sg,
> +				&sg->irq_stat[bank], bank);
> +		if (ret < 0)
> +			memset(&sg->irq_stat[bank], 0,
> +				ARRAY_SIZE(sg->irq_stat));
> +
> +		while (pending) {
> +			unsigned long   bit = __ffs(pending);
> +			unsigned int    irq;
> +
> +			pending &= ~BIT(bit);
> +			irq = bit + sg->irq_base;
> +			handle_nested_irq(irq);
> +		}
> +	}
> +
> +out:
> +	smsc_write(sg->dev, GRP_INT_STAT, status); /* Status is W1C */
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int smsc_irq_setup(struct smsc_gpio *sg)
> +{
> +	unsigned gpio;
> +	int ret;
> +
> +	mutex_init(&sg->irq_lock);
> +
> +	for (gpio = 0; gpio < sg->gpio_chip.ngpio; gpio++) {
> +		int irq = gpio + sg->irq_base;
> +		irq_set_chip_data(irq, sg);
> +		irq_set_chip_and_handler(irq, &smsc_irq_chip,
> +				handle_level_irq);
> +		irq_set_nested_thread(irq, 1);
> +#ifdef CONFIG_ARM
> +		set_irq_flags(irq, IRQF_VALID);
> +#else
> +		irq_set_noprobe(irq);
> +#endif
> +	}
> +
> +	ret = request_threaded_irq(sg->irq, NULL,
> +			smsc_irq_handler, sg->flags,
> +			"smsc_gpio", sg);

would be nice to stick to devm_request_threaded_irq() like on the other
patch.

> +	if (ret) {
> +		dev_err(sg->dev, "failed to request irq %d\n",
> +			sg->irq);
> +	}
> +
> +	sg->gpio_chip.to_irq = smsc_gpio_to_irq;
> +
> +	return 0;
> +}
> +
> +static int __devinit smsc_gpio_probe(struct platform_device *pdev)
> +{
> +	struct smsc_gpio *sg;
> +	struct gpio_chip *gc;
> +	struct smsc *smsc = dev_get_drvdata(pdev->dev.parent);
> +	int ret, i, temp;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	int irq_base;
> +
> +	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
> +	if (sg == NULL) {
> +		dev_err(&pdev->dev, "failed to alloc memory\n");
> +		return -ENOMEM;
> +	}
> +
> +	sg->irq = platform_get_irq(pdev, 0);
> +	if (np) {
> +		of_property_read_u32(np, "gpio,base", &temp);
> +		of_property_read_u32(np, "flags", &sg->flags);
> +	}
> +
> +	gc = &sg->gpio_chip;
> +	gc->direction_input = smsc_gpio_direction_input;
> +	gc->direction_output = smsc_gpio_direction_output;
> +	gc->get = smsc_gpio_get_value;
> +	gc->set = smsc_gpio_set_value;
> +	gc->can_sleep = 1;
> +
> +	gc->base = temp;
> +	gc->ngpio = SMSC_MAXGPIO;
> +	gc->owner = THIS_MODULE;
> +
> +	sg->smsc = smsc;
> +	sg->dev = dev;
> +	mutex_init(&sg->lock);
> +
> +	for (i = 0; i <= SMSC_BANK(SMSC_MAXGPIO); i++)
> +		smsc_read(sg->dev, SMSC_GPIO_DATA_OUT_START + i,
> +					&sg->dat_out[i]);
> +
> +	for (i = 0; i < SMSC_MAXGPIO; i++)
> +		smsc_read(sg->dev, SMSC_CFG_START + i, &sg->dir[i]);
> +
> +	irq_base = irq_alloc_descs(-1, 0, sg->gpio_chip.ngpio, 0);
> +	if (IS_ERR_VALUE(irq_base)) {
> +		dev_err(sg->dev, "Fail to allocate IRQ descs\n");
> +		return irq_base;
> +	}
> +	sg->irq_base = irq_base;
> +
> +	irq_domain_add_legacy(pdev->dev.of_node, sg->gpio_chip.ngpio,
> +		sg->irq_base, 0, &irq_domain_simple_ops, NULL);
> +
> +	ret = smsc_irq_setup(sg);
> +	if (ret)
> +		goto err;
> +
> +	ret = gpiochip_add(&sg->gpio_chip);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	kfree(sg);

using devm_kzalloc(), not needed to free.

> +
> +	return ret;
> +}
> +
> +static int __devexit smsc_gpio_remove(struct platform_device *pdev)
> +{
> +	struct smsc_gpio *sg = dev_get_drvdata(&pdev->dev);
> +	int ret;
> +
> +	ret = gpiochip_remove(&sg->gpio_chip);
> +	if (ret) {
> +		dev_err(&pdev->dev, "gpiochip_remove failed %d\n", ret);
> +		return ret;
> +	}

this will leak the irq (please move to devm_request_threaded_irq).

It's also leaking irq_descs and irq_domain, you need to free those
resources by calling irq_domain_remove and irq_free_descs.
Poddar, Sourav Aug. 21, 2012, 11:47 a.m. UTC | #2
Hi,

On Tue, Aug 21, 2012 at 4:23 PM, Felipe Balbi <balbi@ti.com> wrote:
> Hi,
>
> On Tue, Aug 21, 2012 at 04:15:40PM +0530, Sourav Poddar wrote:
>> smsc can be used as an gpio io expander device also. So adding
>> support for configuring smsc pins as a gpio.
>>
>> Cc: Benoit Cousson <b-cousson@ti.com>
>> Cc: Felipe Balbi <balbi@ti.com>
>> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
>> ---
>>  drivers/gpio/Kconfig        |    7 +
>>  drivers/gpio/Makefile       |    1 +
>>  drivers/gpio/gpio-smscece.c |  373 +++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 381 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/gpio/gpio-smscece.c
>>
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index b16c8a7..e883929 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -444,6 +444,13 @@ config GPIO_ADP5588_IRQ
>>         Say yes here to enable the adp5588 to be used as an interrupt
>>         controller. It requires the driver to be built in the kernel.
>>
>> +config GPIO_SMSCECE
>> +     tristate "SMSCECE 1099 I2C GPIO expander"
>> +     depends on I2C
>> +     help
>> +       This option enables support for 18 GPIOs found
>> +       on SMSC ECE 1099 GPIO Expanders.
>> +
>>  comment "PCI GPIO expanders:"
>>
>>  config GPIO_CS5535
>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>> index 153cace..7c803c5 100644
>> --- a/drivers/gpio/Makefile
>> +++ b/drivers/gpio/Makefile
>> @@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_74X164)   += gpio-74x164.o
>>  obj-$(CONFIG_GPIO_AB8500)    += gpio-ab8500.o
>>  obj-$(CONFIG_GPIO_ADP5520)   += gpio-adp5520.o
>>  obj-$(CONFIG_GPIO_ADP5588)   += gpio-adp5588.o
>> +obj-$(CONFIG_GPIO_SMSCECE)      += gpio-smscece.o
>>  obj-$(CONFIG_GPIO_AMD8111)   += gpio-amd8111.o
>>  obj-$(CONFIG_GPIO_ARIZONA)   += gpio-arizona.o
>>  obj-$(CONFIG_GPIO_BT8XX)     += gpio-bt8xx.o
>> diff --git a/drivers/gpio/gpio-smscece.c b/drivers/gpio/gpio-smscece.c
>> new file mode 100644
>> index 0000000..0cb0959
>> --- /dev/null
>> +++ b/drivers/gpio/gpio-smscece.c
>> @@ -0,0 +1,373 @@
>> +/*
>> + * GPIO Chip driver for smsc
>> + * SMSC I/O Expander and QWERTY Keypad Controller
>> + *
>> + * Copyright 2012 Texas Instruments Inc.
>> + *
>> + * Licensed under the GPL-2 or later.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/slab.h>
>> +#include <linux/init.h>
>> +#include <linux/i2c.h>
>> +#include <linux/gpio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/irqdomain.h>
>> +#include <linux/irq.h>
>> +#include <linux/mfd/smsc.h>
>> +#include <linux/err.h>
>> +
>> +struct smsc_gpio {
>> +     struct device *dev;
>> +     struct smsc *smsc;
>> +     struct gpio_chip gpio_chip;
>> +     struct mutex lock;      /* protect cached dir, dat_out */
>> +     /* protect serialized access to the interrupt controller bus */
>> +     struct mutex irq_lock;
>> +     unsigned gpio_start;
>> +     int type;
>> +     int flags;
>> +     int irq;
>> +     int irq_base;
>> +     unsigned int gpio_base;
>> +     unsigned int dat_out[5];
>> +     unsigned int dir[5];
>> +     unsigned int int_lvl[5];
>> +     unsigned int int_en[5];
>> +     unsigned int irq_mask[5];
>> +     unsigned int irq_stat[5];
>> +};
>> +
>> +static int smsc_gpio_get_value(struct gpio_chip *chip, unsigned off)
>> +{
>> +     struct smsc_gpio *sg =
>> +             container_of(chip, struct smsc_gpio, gpio_chip);
>> +     unsigned int get;
>> +     return !!(smsc_read(sg->dev,
>> +             (SMSC_GPIO_DATA_IN_START + SMSC_BANK(off)) & SMSC_BIT(off),
>> +                                     &get));
>> +}
>> +
>> +static void smsc_gpio_set_value(struct gpio_chip *chip,
>> +                     unsigned off, int val)
>> +{
>> +     unsigned bank, bit;
>> +     struct smsc_gpio *sg =
>> +             container_of(chip, struct smsc_gpio, gpio_chip);
>> +
>> +     bank = SMSC_BANK(off);
>> +     bit = SMSC_BIT(off);
>> +
>> +     mutex_lock(&sg->lock);
>> +     if (val)
>> +             sg->dat_out[bank] |= bit;
>> +     else
>> +             sg->dat_out[bank] &= ~bit;
>> +
>> +     smsc_write(sg->dev, SMSC_GPIO_DATA_OUT_START + bank,
>> +                        sg->dat_out[bank]);
>> +     mutex_unlock(&sg->lock);
>> +}
>> +
>> +static int smsc_gpio_direction_input(struct gpio_chip *chip, unsigned off)
>> +{
>> +     unsigned int reg;
>> +     struct smsc_gpio *sg =
>> +         container_of(chip, struct smsc_gpio, gpio_chip);
>> +     int reg_dir;
>> +
>> +     mutex_lock(&sg->lock);
>> +     reg_dir = SMSC_CFG_START + off;
>> +     smsc_read(sg->dev, reg_dir, &reg);
>> +     reg |= SMSC_GPIO_INPUT_LOW;
>> +     mutex_unlock(&sg->lock);
>> +
>> +     return smsc_write(sg->dev, reg_dir, reg);
>> +}
>> +
>> +static int smsc_gpio_direction_output(struct gpio_chip *chip,
>> +                                      unsigned off, int val)
>> +{
>> +     unsigned int reg;
>> +     struct smsc_gpio *sg =
>> +         container_of(chip, struct smsc_gpio, gpio_chip);
>> +     int reg_dir;
>> +
>> +     mutex_lock(&sg->lock);
>> +     reg_dir = SMSC_CFG_START + off;
>> +     smsc_read(sg->dev, reg_dir, &reg);
>> +     reg |= SMSC_GPIO_OUTPUT_PP;
>> +     mutex_unlock(&sg->lock);
>> +
>> +     return smsc_write(sg->dev, reg_dir, reg);
>> +}
>> +
>> +static int smsc_gpio_to_irq(struct gpio_chip *chip, unsigned off)
>> +{
>> +     struct smsc_gpio *sg =
>> +             container_of(chip, struct smsc_gpio, gpio_chip);
>> +     return sg->irq_base + off;
>> +}
>> +
>> +static void smsc_irq_bus_lock(struct irq_data *d)
>> +{
>> +     struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
>> +
>> +     mutex_lock(&sg->irq_lock);
>> +}
>> +
>> +static void smsc_irq_bus_sync_unlock(struct irq_data *d)
>> +{
>> +     struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
>> +     int i;
>> +
>> +     for (i = 0; i < SMSC_BANK(SMSC_MAXGPIO); i++)
>> +             if (sg->int_en[i] ^ sg->irq_mask[i]) {
>> +                     sg->int_en[i] = sg->irq_mask[i];
>> +                     smsc_write(sg->dev, SMSC_GPIO_INT_MASK_START + i,
>> +                                        sg->int_en[i]);
>> +             }
>> +
>> +     mutex_unlock(&sg->irq_lock);
>> +}
>> +
>> +static void smsc_irq_mask(struct irq_data *d)
>> +{
>> +     struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
>> +     unsigned gpio = d->irq - sg->irq_base;
>> +
>> +     sg->irq_mask[SMSC_BANK(gpio)] &= ~SMSC_BIT(gpio);
>> +}
>> +
>> +static void smsc_irq_unmask(struct irq_data *d)
>> +{
>> +     struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
>> +     unsigned gpio = d->irq - sg->irq_base;
>> +
>> +     sg->irq_mask[SMSC_BANK(gpio)] |= SMSC_BIT(gpio);
>> +}
>> +
>> +static int smsc_irq_set_type(struct irq_data *d, unsigned int type)
>> +{
>> +     struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
>> +     uint16_t gpio = d->irq - sg->irq_base;
>> +     unsigned bank, bit;
>> +
>> +     if ((type & IRQ_TYPE_EDGE_BOTH)) {
>> +             dev_err(sg->dev, "irq %d: unsupported type %d\n",
>> +                     d->irq, type);
>> +             return -EINVAL;
>> +     }
>> +
>> +     bank = SMSC_BANK(gpio);
>> +     bit = SMSC_BIT(gpio);
>> +
>> +     if (type & IRQ_TYPE_LEVEL_HIGH)
>> +             sg->int_lvl[bank] |= bit;
>> +     else if (type & IRQ_TYPE_LEVEL_LOW)
>> +             sg->int_lvl[bank] &= ~bit;
>> +     else
>> +             return -EINVAL;
>
> this looks wrong. You could have a user who wants to trigger on both
> HIGH and LOW levels, no ?
>
Yes, I think there can be a scenario where gpio_keys are attached
to this driver and signals a "key press" at low and "key release" at
high. ?
 Will figure out a way to add support to check for case where
both High and low levels are used.
>> +     smsc_gpio_direction_input(&sg->gpio_chip, gpio);
>> +     smsc_write(sg->dev, SMSC_CFG_START + gpio,
>> +                     sg->int_lvl[bank]);
>> +
>> +     return 0;
>> +}
>> +
>> +static struct irq_chip smsc_irq_chip = {
>> +     .name                   = "smsc",
>> +     .irq_mask               = smsc_irq_mask,
>> +     .irq_unmask             = smsc_irq_unmask,
>> +     .irq_bus_lock           = smsc_irq_bus_lock,
>> +     .irq_bus_sync_unlock    = smsc_irq_bus_sync_unlock,
>> +     .irq_set_type           = smsc_irq_set_type,
>> +};
>> +
>> +static int smsc_gpio_read_intstat(struct smsc_gpio *sg,
>> +                             unsigned int *buf, int i)
>> +{
>> +     int ret = smsc_read(sg->dev,
>> +                     SMSC_GPIO_INT_STAT_START + i, buf);
>> +
>> +     if (ret < 0)
>> +             dev_err(sg->dev, "Read INT_STAT Error\n");
>> +
>> +     return ret;
>> +}
>> +
>> +static irqreturn_t smsc_irq_handler(int irq, void *devid)
>> +{
>> +     struct smsc_gpio *sg = devid;
>> +     unsigned int status, bank, pending;
>> +     int ret;
>> +     smsc_read(sg->dev, GRP_INT_STAT, &status);
>> +
>> +     if (!(status & SMSC_GPI_INT))
>> +             goto out;
>> +
>> +     for (bank = 0; bank <= SMSC_BANK(SMSC_MAXGPIO);
>> +             bank++) {
>> +             pending = sg->irq_stat[bank] & sg->irq_mask[bank];
>> +             ret = smsc_gpio_read_intstat(sg,
>> +                             &sg->irq_stat[bank], bank);
>> +             if (ret < 0)
>> +                     memset(&sg->irq_stat[bank], 0,
>> +                             ARRAY_SIZE(sg->irq_stat));
>> +
>> +             while (pending) {
>> +                     unsigned long   bit = __ffs(pending);
>> +                     unsigned int    irq;
>> +
>> +                     pending &= ~BIT(bit);
>> +                     irq = bit + sg->irq_base;
>> +                     handle_nested_irq(irq);
>> +             }
>> +     }
>> +
>> +out:
>> +     smsc_write(sg->dev, GRP_INT_STAT, status); /* Status is W1C */
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static int smsc_irq_setup(struct smsc_gpio *sg)
>> +{
>> +     unsigned gpio;
>> +     int ret;
>> +
>> +     mutex_init(&sg->irq_lock);
>> +
>> +     for (gpio = 0; gpio < sg->gpio_chip.ngpio; gpio++) {
>> +             int irq = gpio + sg->irq_base;
>> +             irq_set_chip_data(irq, sg);
>> +             irq_set_chip_and_handler(irq, &smsc_irq_chip,
>> +                             handle_level_irq);
>> +             irq_set_nested_thread(irq, 1);
>> +#ifdef CONFIG_ARM
>> +             set_irq_flags(irq, IRQF_VALID);
>> +#else
>> +             irq_set_noprobe(irq);
>> +#endif
>> +     }
>> +
>> +     ret = request_threaded_irq(sg->irq, NULL,
>> +                     smsc_irq_handler, sg->flags,
>> +                     "smsc_gpio", sg);
>
> would be nice to stick to devm_request_threaded_irq() like on the other
> patch.
>
Yes, will change.
>> +     if (ret) {
>> +             dev_err(sg->dev, "failed to request irq %d\n",
>> +                     sg->irq);
>> +     }
>> +
>> +     sg->gpio_chip.to_irq = smsc_gpio_to_irq;
>> +
>> +     return 0;
>> +}
>> +
>> +static int __devinit smsc_gpio_probe(struct platform_device *pdev)
>> +{
>> +     struct smsc_gpio *sg;
>> +     struct gpio_chip *gc;
>> +     struct smsc *smsc = dev_get_drvdata(pdev->dev.parent);
>> +     int ret, i, temp;
>> +     struct device *dev = &pdev->dev;
>> +     struct device_node *np = dev->of_node;
>> +     int irq_base;
>> +
>> +     sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
>> +     if (sg == NULL) {
>> +             dev_err(&pdev->dev, "failed to alloc memory\n");
>> +             return -ENOMEM;
>> +     }
>> +
>> +     sg->irq = platform_get_irq(pdev, 0);
>> +     if (np) {
>> +             of_property_read_u32(np, "gpio,base", &temp);
>> +             of_property_read_u32(np, "flags", &sg->flags);
>> +     }
>> +
>> +     gc = &sg->gpio_chip;
>> +     gc->direction_input = smsc_gpio_direction_input;
>> +     gc->direction_output = smsc_gpio_direction_output;
>> +     gc->get = smsc_gpio_get_value;
>> +     gc->set = smsc_gpio_set_value;
>> +     gc->can_sleep = 1;
>> +
>> +     gc->base = temp;
>> +     gc->ngpio = SMSC_MAXGPIO;
>> +     gc->owner = THIS_MODULE;
>> +
>> +     sg->smsc = smsc;
>> +     sg->dev = dev;
>> +     mutex_init(&sg->lock);
>> +
>> +     for (i = 0; i <= SMSC_BANK(SMSC_MAXGPIO); i++)
>> +             smsc_read(sg->dev, SMSC_GPIO_DATA_OUT_START + i,
>> +                                     &sg->dat_out[i]);
>> +
>> +     for (i = 0; i < SMSC_MAXGPIO; i++)
>> +             smsc_read(sg->dev, SMSC_CFG_START + i, &sg->dir[i]);
>> +
>> +     irq_base = irq_alloc_descs(-1, 0, sg->gpio_chip.ngpio, 0);
>> +     if (IS_ERR_VALUE(irq_base)) {
>> +             dev_err(sg->dev, "Fail to allocate IRQ descs\n");
>> +             return irq_base;
>> +     }
>> +     sg->irq_base = irq_base;
>> +
>> +     irq_domain_add_legacy(pdev->dev.of_node, sg->gpio_chip.ngpio,
>> +             sg->irq_base, 0, &irq_domain_simple_ops, NULL);
>> +
>> +     ret = smsc_irq_setup(sg);
>> +     if (ret)
>> +             goto err;
>> +
>> +     ret = gpiochip_add(&sg->gpio_chip);
>> +     if (ret)
>> +             goto err;
>> +
>> +     return 0;
>> +
>> +err:
>> +     kfree(sg);
>
> using devm_kzalloc(), not needed to free.
>
True, will change.
>> +
>> +     return ret;
>> +}
>> +
>> +static int __devexit smsc_gpio_remove(struct platform_device *pdev)
>> +{
>> +     struct smsc_gpio *sg = dev_get_drvdata(&pdev->dev);
>> +     int ret;
>> +
>> +     ret = gpiochip_remove(&sg->gpio_chip);
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "gpiochip_remove failed %d\n", ret);
>> +             return ret;
>> +     }
>
> this will leak the irq (please move to devm_request_threaded_irq).
>
> It's also leaking irq_descs and irq_domain, you need to free those
> resources by calling irq_domain_remove and irq_free_descs.
>
Ok. will add the above apis in the next version.
> --
> balbi
Felipe Balbi Aug. 21, 2012, noon UTC | #3
Hi,

On Tue, Aug 21, 2012 at 05:17:37PM +0530, Poddar, Sourav wrote:
> >> +     if (type & IRQ_TYPE_LEVEL_HIGH)
> >> +             sg->int_lvl[bank] |= bit;
> >> +     else if (type & IRQ_TYPE_LEVEL_LOW)
> >> +             sg->int_lvl[bank] &= ~bit;
> >> +     else
> >> +             return -EINVAL;
> >
> > this looks wrong. You could have a user who wants to trigger on both
> > HIGH and LOW levels, no ?
> >
> Yes, I think there can be a scenario where gpio_keys are attached
> to this driver and signals a "key press" at low and "key release" at
> high. ?
>  Will figure out a way to add support to check for case where
> both High and low levels are used.

could probably be done on a separate patch, maybe... Just now I saw that
HIGH and LOW levels use the same bit.
Poddar, Sourav Aug. 21, 2012, 12:20 p.m. UTC | #4
Hi,

On Tue, Aug 21, 2012 at 5:30 PM, Felipe Balbi <balbi@ti.com> wrote:
> Hi,
>
> On Tue, Aug 21, 2012 at 05:17:37PM +0530, Poddar, Sourav wrote:
>> >> +     if (type & IRQ_TYPE_LEVEL_HIGH)
>> >> +             sg->int_lvl[bank] |= bit;
>> >> +     else if (type & IRQ_TYPE_LEVEL_LOW)
>> >> +             sg->int_lvl[bank] &= ~bit;
>> >> +     else
>> >> +             return -EINVAL;
>> >
>> > this looks wrong. You could have a user who wants to trigger on both
>> > HIGH and LOW levels, no ?
>> >
>> Yes, I think there can be a scenario where gpio_keys are attached
>> to this driver and signals a "key press" at low and "key release" at
>> high. ?
>>  Will figure out a way to add support to check for case where
>> both High and low levels are used.
>
> could probably be done on a separate patch, maybe... Just now I saw that
> HIGH and LOW levels use the same bit.
>
If I am understanding correctly, if they both uses the same bit we cannot
use both for a particular user. ?
> --
> balbi
Felipe Balbi Aug. 21, 2012, 12:22 p.m. UTC | #5
On Tue, Aug 21, 2012 at 05:50:28PM +0530, Poddar, Sourav wrote:
> Hi,
> 
> On Tue, Aug 21, 2012 at 5:30 PM, Felipe Balbi <balbi@ti.com> wrote:
> > Hi,
> >
> > On Tue, Aug 21, 2012 at 05:17:37PM +0530, Poddar, Sourav wrote:
> >> >> +     if (type & IRQ_TYPE_LEVEL_HIGH)
> >> >> +             sg->int_lvl[bank] |= bit;
> >> >> +     else if (type & IRQ_TYPE_LEVEL_LOW)
> >> >> +             sg->int_lvl[bank] &= ~bit;
> >> >> +     else
> >> >> +             return -EINVAL;
> >> >
> >> > this looks wrong. You could have a user who wants to trigger on both
> >> > HIGH and LOW levels, no ?
> >> >
> >> Yes, I think there can be a scenario where gpio_keys are attached
> >> to this driver and signals a "key press" at low and "key release" at
> >> high. ?
> >>  Will figure out a way to add support to check for case where
> >> both High and low levels are used.
> >
> > could probably be done on a separate patch, maybe... Just now I saw that
> > HIGH and LOW levels use the same bit.
> >
> If I am understanding correctly, if they both uses the same bit we cannot
> use both for a particular user. ?

we can, it's just a bit more complex. If a user request both LOW and
HIGH, then you start with HIGH, once it triggers, before calling the
nested IRQ handler, you need to change it LOW. When low triggers, before
calling the nested IRQ handler, you need to change it to HIGH again. And
so on. I'm just not sure if that's valid on linux IRQ subsystem.

Anyone ?
Mark Brown Aug. 21, 2012, 2:50 p.m. UTC | #6
On Tue, Aug 21, 2012 at 03:22:18PM +0300, Felipe Balbi wrote:
> On Tue, Aug 21, 2012 at 05:50:28PM +0530, Poddar, Sourav wrote:

> > If I am understanding correctly, if they both uses the same bit we cannot
> > use both for a particular user. ?

> we can, it's just a bit more complex. If a user request both LOW and
> HIGH, then you start with HIGH, once it triggers, before calling the
> nested IRQ handler, you need to change it LOW. When low triggers, before
> calling the nested IRQ handler, you need to change it to HIGH again. And
> so on. I'm just not sure if that's valid on linux IRQ subsystem.

The given example was for keypress - usually a system would use edge
triggered interrupts in combination with reading the GPIO state rather
than level triggered interrupts.
diff mbox

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b16c8a7..e883929 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -444,6 +444,13 @@  config GPIO_ADP5588_IRQ
 	  Say yes here to enable the adp5588 to be used as an interrupt
 	  controller. It requires the driver to be built in the kernel.
 
+config GPIO_SMSCECE
+	tristate "SMSCECE 1099 I2C GPIO expander"
+	depends on I2C
+	help
+	  This option enables support for 18 GPIOs found
+	  on SMSC ECE 1099 GPIO Expanders.
+
 comment "PCI GPIO expanders:"
 
 config GPIO_CS5535
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 153cace..7c803c5 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -12,6 +12,7 @@  obj-$(CONFIG_GPIO_74X164)	+= gpio-74x164.o
 obj-$(CONFIG_GPIO_AB8500)	+= gpio-ab8500.o
 obj-$(CONFIG_GPIO_ADP5520)	+= gpio-adp5520.o
 obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o
+obj-$(CONFIG_GPIO_SMSCECE)      += gpio-smscece.o
 obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o
 obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o
 obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-smscece.c b/drivers/gpio/gpio-smscece.c
new file mode 100644
index 0000000..0cb0959
--- /dev/null
+++ b/drivers/gpio/gpio-smscece.c
@@ -0,0 +1,373 @@ 
+/*
+ * GPIO Chip driver for smsc
+ * SMSC I/O Expander and QWERTY Keypad Controller
+ *
+ * Copyright 2012 Texas Instruments Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/mfd/smsc.h>
+#include <linux/err.h>
+
+struct smsc_gpio {
+	struct device *dev;
+	struct smsc *smsc;
+	struct gpio_chip gpio_chip;
+	struct mutex lock;	/* protect cached dir, dat_out */
+	/* protect serialized access to the interrupt controller bus */
+	struct mutex irq_lock;
+	unsigned gpio_start;
+	int type;
+	int flags;
+	int irq;
+	int irq_base;
+	unsigned int gpio_base;
+	unsigned int dat_out[5];
+	unsigned int dir[5];
+	unsigned int int_lvl[5];
+	unsigned int int_en[5];
+	unsigned int irq_mask[5];
+	unsigned int irq_stat[5];
+};
+
+static int smsc_gpio_get_value(struct gpio_chip *chip, unsigned off)
+{
+	struct smsc_gpio *sg =
+		container_of(chip, struct smsc_gpio, gpio_chip);
+	unsigned int get;
+	return !!(smsc_read(sg->dev,
+		(SMSC_GPIO_DATA_IN_START + SMSC_BANK(off)) & SMSC_BIT(off),
+					&get));
+}
+
+static void smsc_gpio_set_value(struct gpio_chip *chip,
+			unsigned off, int val)
+{
+	unsigned bank, bit;
+	struct smsc_gpio *sg =
+		container_of(chip, struct smsc_gpio, gpio_chip);
+
+	bank = SMSC_BANK(off);
+	bit = SMSC_BIT(off);
+
+	mutex_lock(&sg->lock);
+	if (val)
+		sg->dat_out[bank] |= bit;
+	else
+		sg->dat_out[bank] &= ~bit;
+
+	smsc_write(sg->dev, SMSC_GPIO_DATA_OUT_START + bank,
+			   sg->dat_out[bank]);
+	mutex_unlock(&sg->lock);
+}
+
+static int smsc_gpio_direction_input(struct gpio_chip *chip, unsigned off)
+{
+	unsigned int reg;
+	struct smsc_gpio *sg =
+	    container_of(chip, struct smsc_gpio, gpio_chip);
+	int reg_dir;
+
+	mutex_lock(&sg->lock);
+	reg_dir = SMSC_CFG_START + off;
+	smsc_read(sg->dev, reg_dir, &reg);
+	reg |= SMSC_GPIO_INPUT_LOW;
+	mutex_unlock(&sg->lock);
+
+	return smsc_write(sg->dev, reg_dir, reg);
+}
+
+static int smsc_gpio_direction_output(struct gpio_chip *chip,
+					 unsigned off, int val)
+{
+	unsigned int reg;
+	struct smsc_gpio *sg =
+	    container_of(chip, struct smsc_gpio, gpio_chip);
+	int reg_dir;
+
+	mutex_lock(&sg->lock);
+	reg_dir = SMSC_CFG_START + off;
+	smsc_read(sg->dev, reg_dir, &reg);
+	reg |= SMSC_GPIO_OUTPUT_PP;
+	mutex_unlock(&sg->lock);
+
+	return smsc_write(sg->dev, reg_dir, reg);
+}
+
+static int smsc_gpio_to_irq(struct gpio_chip *chip, unsigned off)
+{
+	struct smsc_gpio *sg =
+		container_of(chip, struct smsc_gpio, gpio_chip);
+	return sg->irq_base + off;
+}
+
+static void smsc_irq_bus_lock(struct irq_data *d)
+{
+	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+
+	mutex_lock(&sg->irq_lock);
+}
+
+static void smsc_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+	int i;
+
+	for (i = 0; i < SMSC_BANK(SMSC_MAXGPIO); i++)
+		if (sg->int_en[i] ^ sg->irq_mask[i]) {
+			sg->int_en[i] = sg->irq_mask[i];
+			smsc_write(sg->dev, SMSC_GPIO_INT_MASK_START + i,
+					   sg->int_en[i]);
+		}
+
+	mutex_unlock(&sg->irq_lock);
+}
+
+static void smsc_irq_mask(struct irq_data *d)
+{
+	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->irq - sg->irq_base;
+
+	sg->irq_mask[SMSC_BANK(gpio)] &= ~SMSC_BIT(gpio);
+}
+
+static void smsc_irq_unmask(struct irq_data *d)
+{
+	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+	unsigned gpio = d->irq - sg->irq_base;
+
+	sg->irq_mask[SMSC_BANK(gpio)] |= SMSC_BIT(gpio);
+}
+
+static int smsc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+	uint16_t gpio = d->irq - sg->irq_base;
+	unsigned bank, bit;
+
+	if ((type & IRQ_TYPE_EDGE_BOTH)) {
+		dev_err(sg->dev, "irq %d: unsupported type %d\n",
+			d->irq, type);
+		return -EINVAL;
+	}
+
+	bank = SMSC_BANK(gpio);
+	bit = SMSC_BIT(gpio);
+
+	if (type & IRQ_TYPE_LEVEL_HIGH)
+		sg->int_lvl[bank] |= bit;
+	else if (type & IRQ_TYPE_LEVEL_LOW)
+		sg->int_lvl[bank] &= ~bit;
+	else
+		return -EINVAL;
+
+	smsc_gpio_direction_input(&sg->gpio_chip, gpio);
+	smsc_write(sg->dev, SMSC_CFG_START + gpio,
+			sg->int_lvl[bank]);
+
+	return 0;
+}
+
+static struct irq_chip smsc_irq_chip = {
+	.name			= "smsc",
+	.irq_mask		= smsc_irq_mask,
+	.irq_unmask		= smsc_irq_unmask,
+	.irq_bus_lock		= smsc_irq_bus_lock,
+	.irq_bus_sync_unlock	= smsc_irq_bus_sync_unlock,
+	.irq_set_type		= smsc_irq_set_type,
+};
+
+static int smsc_gpio_read_intstat(struct smsc_gpio *sg,
+				unsigned int *buf, int i)
+{
+	int ret = smsc_read(sg->dev,
+			SMSC_GPIO_INT_STAT_START + i, buf);
+
+	if (ret < 0)
+		dev_err(sg->dev, "Read INT_STAT Error\n");
+
+	return ret;
+}
+
+static irqreturn_t smsc_irq_handler(int irq, void *devid)
+{
+	struct smsc_gpio *sg = devid;
+	unsigned int status, bank, pending;
+	int ret;
+	smsc_read(sg->dev, GRP_INT_STAT, &status);
+
+	if (!(status & SMSC_GPI_INT))
+		goto out;
+
+	for (bank = 0; bank <= SMSC_BANK(SMSC_MAXGPIO);
+		bank++) {
+		pending = sg->irq_stat[bank] & sg->irq_mask[bank];
+		ret = smsc_gpio_read_intstat(sg,
+				&sg->irq_stat[bank], bank);
+		if (ret < 0)
+			memset(&sg->irq_stat[bank], 0,
+				ARRAY_SIZE(sg->irq_stat));
+
+		while (pending) {
+			unsigned long   bit = __ffs(pending);
+			unsigned int    irq;
+
+			pending &= ~BIT(bit);
+			irq = bit + sg->irq_base;
+			handle_nested_irq(irq);
+		}
+	}
+
+out:
+	smsc_write(sg->dev, GRP_INT_STAT, status); /* Status is W1C */
+
+	return IRQ_HANDLED;
+}
+
+static int smsc_irq_setup(struct smsc_gpio *sg)
+{
+	unsigned gpio;
+	int ret;
+
+	mutex_init(&sg->irq_lock);
+
+	for (gpio = 0; gpio < sg->gpio_chip.ngpio; gpio++) {
+		int irq = gpio + sg->irq_base;
+		irq_set_chip_data(irq, sg);
+		irq_set_chip_and_handler(irq, &smsc_irq_chip,
+				handle_level_irq);
+		irq_set_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+		set_irq_flags(irq, IRQF_VALID);
+#else
+		irq_set_noprobe(irq);
+#endif
+	}
+
+	ret = request_threaded_irq(sg->irq, NULL,
+			smsc_irq_handler, sg->flags,
+			"smsc_gpio", sg);
+	if (ret) {
+		dev_err(sg->dev, "failed to request irq %d\n",
+			sg->irq);
+	}
+
+	sg->gpio_chip.to_irq = smsc_gpio_to_irq;
+
+	return 0;
+}
+
+static int __devinit smsc_gpio_probe(struct platform_device *pdev)
+{
+	struct smsc_gpio *sg;
+	struct gpio_chip *gc;
+	struct smsc *smsc = dev_get_drvdata(pdev->dev.parent);
+	int ret, i, temp;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int irq_base;
+
+	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
+	if (sg == NULL) {
+		dev_err(&pdev->dev, "failed to alloc memory\n");
+		return -ENOMEM;
+	}
+
+	sg->irq = platform_get_irq(pdev, 0);
+	if (np) {
+		of_property_read_u32(np, "gpio,base", &temp);
+		of_property_read_u32(np, "flags", &sg->flags);
+	}
+
+	gc = &sg->gpio_chip;
+	gc->direction_input = smsc_gpio_direction_input;
+	gc->direction_output = smsc_gpio_direction_output;
+	gc->get = smsc_gpio_get_value;
+	gc->set = smsc_gpio_set_value;
+	gc->can_sleep = 1;
+
+	gc->base = temp;
+	gc->ngpio = SMSC_MAXGPIO;
+	gc->owner = THIS_MODULE;
+
+	sg->smsc = smsc;
+	sg->dev = dev;
+	mutex_init(&sg->lock);
+
+	for (i = 0; i <= SMSC_BANK(SMSC_MAXGPIO); i++)
+		smsc_read(sg->dev, SMSC_GPIO_DATA_OUT_START + i,
+					&sg->dat_out[i]);
+
+	for (i = 0; i < SMSC_MAXGPIO; i++)
+		smsc_read(sg->dev, SMSC_CFG_START + i, &sg->dir[i]);
+
+	irq_base = irq_alloc_descs(-1, 0, sg->gpio_chip.ngpio, 0);
+	if (IS_ERR_VALUE(irq_base)) {
+		dev_err(sg->dev, "Fail to allocate IRQ descs\n");
+		return irq_base;
+	}
+	sg->irq_base = irq_base;
+
+	irq_domain_add_legacy(pdev->dev.of_node, sg->gpio_chip.ngpio,
+		sg->irq_base, 0, &irq_domain_simple_ops, NULL);
+
+	ret = smsc_irq_setup(sg);
+	if (ret)
+		goto err;
+
+	ret = gpiochip_add(&sg->gpio_chip);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	kfree(sg);
+
+	return ret;
+}
+
+static int __devexit smsc_gpio_remove(struct platform_device *pdev)
+{
+	struct smsc_gpio *sg = dev_get_drvdata(&pdev->dev);
+	int ret;
+
+	ret = gpiochip_remove(&sg->gpio_chip);
+	if (ret) {
+		dev_err(&pdev->dev, "gpiochip_remove failed %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id smsc_gpio_dt_match[] = {
+	{ .compatible = "smsc,gpio" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, smsc_gpio_dt_match);
+
+static struct platform_driver smsc_gpio_driver = {
+	.driver = {
+		   .name = "smsc_gpio",
+		   .of_match_table = of_match_ptr(smsc_gpio_dt_match),
+		   },
+	.probe = smsc_gpio_probe,
+	.remove = __devexit_p(smsc_gpio_remove),
+};
+
+module_platform_driver(smsc_gpio_driver);
+
+MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
+MODULE_DESCRIPTION("GPIO SMSC Driver");
+MODULE_LICENSE("GPL v2");