[2/4] gpio: Add RDA Micro GPIO controller support
diff mbox series

Message ID 20191013114037.9845-3-manivannan.sadhasivam@linaro.org
State New
Headers show
Series
  • Add GPIO support for RDA8810PL SoC
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Commit Message

Manivannan Sadhasivam Oct. 13, 2019, 11:40 a.m. UTC
Add support for GPIO controller from RDA Micro.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/gpio/Kconfig    |   8 +
 drivers/gpio/Makefile   |   1 +
 drivers/gpio/gpio-rda.c | 334 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 343 insertions(+)
 create mode 100644 drivers/gpio/gpio-rda.c

Comments

Bartosz Golaszewski Oct. 14, 2019, 2:25 p.m. UTC | #1
niedz., 13 paź 2019 o 13:40 Manivannan Sadhasivam
<manivannan.sadhasivam@linaro.org> napisał(a):
>
> Add support for GPIO controller from RDA Micro.

Looks nice and clean, just a couple nits.

>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/gpio/Kconfig    |   8 +
>  drivers/gpio/Makefile   |   1 +
>  drivers/gpio/gpio-rda.c | 334 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 343 insertions(+)
>  create mode 100644 drivers/gpio/gpio-rda.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 38e096e6925f..71826e61fdb3 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -435,6 +435,14 @@ config GPIO_RCAR
>         help
>           Say yes here to support GPIO on Renesas R-Car SoCs.
>
> +config GPIO_RDA
> +       bool "RDA Micro GPIO controller support"
> +       depends on ARCH_RDA || COMPILE_TEST
> +       depends on OF_GPIO
> +       select GPIOLIB_IRQCHIP
> +       help
> +         Say Y here to support RDA Micro GPIO controller.
> +
>  config GPIO_REG
>         bool
>         help
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index d2fd19c15bae..5c68c9a48fa3 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -115,6 +115,7 @@ obj-$(CONFIG_GPIO_PXA)                      += gpio-pxa.o
>  obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)     += gpio-raspberrypi-exp.o
>  obj-$(CONFIG_GPIO_RC5T583)             += gpio-rc5t583.o
>  obj-$(CONFIG_GPIO_RCAR)                        += gpio-rcar.o
> +obj-$(CONFIG_GPIO_RDA)                 += gpio-rda.o
>  obj-$(CONFIG_GPIO_RDC321X)             += gpio-rdc321x.o
>  obj-$(CONFIG_GPIO_REG)                 += gpio-reg.o
>  obj-$(CONFIG_ARCH_SA1100)              += gpio-sa1100.o
> diff --git a/drivers/gpio/gpio-rda.c b/drivers/gpio/gpio-rda.c
> new file mode 100644
> index 000000000000..5a4adeb25f72
> --- /dev/null
> +++ b/drivers/gpio/gpio-rda.c
> @@ -0,0 +1,334 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * RDA Micro GPIO driver
> + *
> + * Copyright (C) 2012 RDA Micro Inc.
> + * Copyright (C) 2019 Manivannan Sadhasivam
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +
> +#define RDA_GPIO_OEN_VAL               0x00
> +#define RDA_GPIO_OEN_SET_OUT           0x04
> +#define RDA_GPIO_OEN_SET_IN            0x08
> +#define RDA_GPIO_VAL                   0x0c
> +#define RDA_GPIO_SET                   0x10
> +#define RDA_GPIO_CLR                   0x14
> +#define RDA_GPIO_INT_CTRL_SET          0x18
> +#define RDA_GPIO_INT_CTRL_CLR          0x1c
> +#define RDA_GPIO_INT_CLR               0x20
> +#define RDA_GPIO_INT_STATUS            0x24
> +
> +#define RDA_GPIO_IRQ_RISE_SHIFT                0
> +#define RDA_GPIO_IRQ_FALL_SHIFT                8
> +#define RDA_GPIO_DEBOUCE_SHIFT         16
> +#define RDA_GPIO_LEVEL_SHIFT           24
> +
> +#define RDA_GPIO_IRQ_MASK              0xff
> +
> +/* Each bank consists of 32 GPIOs */
> +#define RDA_GPIO_BANK_NR       32
> +
> +struct rda_gpio {
> +       struct gpio_chip chip;
> +       void __iomem *base;
> +       spinlock_t lock;
> +       struct irq_chip irq_chip;
> +       int irq;
> +};
> +
> +static void rda_gpio_update(struct gpio_chip *chip, unsigned int offset,
> +                           u16 reg, int val)
> +{
> +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> +       void __iomem *base = rda_gpio->base;
> +       unsigned long flags;
> +       u32 tmp;
> +
> +       spin_lock_irqsave(&rda_gpio->lock, flags);
> +       tmp = readl_relaxed(base + reg);
> +
> +       if (val)
> +               tmp |= BIT(offset);
> +       else
> +               tmp &= ~BIT(offset);
> +
> +       writel_relaxed(tmp, base + reg);
> +       spin_unlock_irqrestore(&rda_gpio->lock, flags);
> +}

If you used the mmio regmap, you could save all this code and reuse
regmap's update helpers. This is just a suggestion, not a requirement
though.

> +
> +static int rda_gpio_request(struct gpio_chip *chip, unsigned int offset)
> +{
> +       /* Not supported currently */
> +       return 0;
> +}
> +
> +static void rda_gpio_free(struct gpio_chip *chip, unsigned int offset)
> +{
> +       /* Not supported currently */
> +}

Just don't implement these callbacks if they're doing nothing.

> +
> +static int rda_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
> +{
> +       rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_IN, 1);
> +
> +       return 0;
> +}
> +
> +static int rda_gpio_direction_output(struct gpio_chip *chip,
> +                                    unsigned int offset, int value)
> +{
> +       rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_OUT, 1);
> +
> +       return 0;
> +}
> +
> +static int rda_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> +       void __iomem *base = rda_gpio->base;
> +
> +       if (readl_relaxed(base + RDA_GPIO_OEN_VAL) & BIT(offset))
> +               return !!(readl_relaxed(base + RDA_GPIO_VAL) & BIT(offset));
> +       else
> +               return !!(readl_relaxed(base + RDA_GPIO_SET) & BIT(offset));
> +}
> +
> +static void rda_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
> +{
> +       if (value)
> +               rda_gpio_update(chip, offset, RDA_GPIO_SET, 1);
> +       else
> +               rda_gpio_update(chip, offset, RDA_GPIO_CLR, 1);
> +}
> +
> +static void rda_gpio_irq_mask(struct irq_data *data)
> +{
> +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> +       void __iomem *base = rda_gpio->base;
> +       u32 offset = irqd_to_hwirq(data);
> +       u32 value;
> +
> +       value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> +       value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> +
> +       writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> +}
> +
> +static void rda_gpio_irq_ack(struct irq_data *data)
> +{
> +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> +       u32 offset = irqd_to_hwirq(data);
> +
> +       rda_gpio_update(chip, offset, RDA_GPIO_INT_CLR, 1);
> +}
> +
> +static int rda_gpio_set_irq(struct gpio_chip *chip, u32 offset,
> +                           unsigned int flow_type)
> +{
> +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> +       void __iomem *base = rda_gpio->base;
> +       u32 value;
> +
> +       switch (flow_type) {
> +       case IRQ_TYPE_EDGE_RISING:
> +               /* Set rising edge trigger */
> +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> +
> +               /* Switch to edge trigger interrupt */
> +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> +               break;
> +
> +       case IRQ_TYPE_EDGE_FALLING:
> +               /* Set falling edge trigger */
> +               value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> +
> +               /* Switch to edge trigger interrupt */
> +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> +               break;
> +
> +       case IRQ_TYPE_EDGE_BOTH:
> +               /* Set both edge trigger */
> +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> +               value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> +
> +               /* Switch to edge trigger interrupt */
> +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> +               break;
> +
> +       case IRQ_TYPE_LEVEL_HIGH:
> +               /* Set high level trigger */
> +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> +
> +               /* Switch to level trigger interrupt */
> +               value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> +               break;
> +
> +       case IRQ_TYPE_LEVEL_LOW:
> +               /* Set low level trigger */
> +               value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> +
> +               /* Switch to level trigger interrupt */
> +               value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> +               break;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +static void rda_gpio_irq_unmask(struct irq_data *data)
> +{
> +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> +       u32 offset = irqd_to_hwirq(data);
> +       u32 trigger = irqd_get_trigger_type(data);
> +
> +       rda_gpio_set_irq(chip, offset, trigger);
> +}
> +
> +static int rda_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
> +{
> +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> +       u32 offset = irqd_to_hwirq(data);
> +       int ret;
> +
> +       ret = rda_gpio_set_irq(chip, offset, flow_type);
> +       if (ret)
> +               return ret;
> +
> +       if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
> +               irq_set_handler_locked(data, handle_level_irq);
> +       else if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
> +               irq_set_handler_locked(data, handle_edge_irq);
> +
> +       return 0;
> +}
> +
> +static void rda_gpio_irq_handler(struct irq_desc *desc)
> +{
> +       struct gpio_chip *chip = irq_desc_get_handler_data(desc);
> +       struct irq_chip *ic = irq_desc_get_chip(desc);
> +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> +       unsigned long status;
> +       u32 n, girq;
> +
> +       chained_irq_enter(ic, desc);
> +
> +       status = readl_relaxed(rda_gpio->base + RDA_GPIO_INT_STATUS);
> +       /* Only lower 8 bits are capable of generating interrupts */
> +       status &= RDA_GPIO_IRQ_MASK;
> +
> +       for_each_set_bit(n, &status, RDA_GPIO_BANK_NR) {
> +               girq = irq_find_mapping(chip->irq.domain, n);
> +               generic_handle_irq(girq);
> +       }
> +
> +       chained_irq_exit(ic, desc);
> +}
> +
> +static int rda_gpio_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct gpio_irq_chip *irq;

Can you call this variable irq_chip? Visually it interferes with
rda_gpio->irq too much.

> +       struct rda_gpio *rda_gpio;
> +       u32 ngpios;
> +       int ret;
> +
> +       rda_gpio = devm_kzalloc(&pdev->dev, sizeof(*rda_gpio), GFP_KERNEL);
> +       if (!rda_gpio)
> +               return -ENOMEM;
> +
> +       ret = of_property_read_u32(np, "ngpios", &ngpios);
> +       if (ret < 0)
> +               return ret;
> +

Please use the generic device property helpers unless it's really
necessary to use of_ variants. Also: remove the of_device.h include.

> +       /*
> +        * Not all ports have interrupt capability. For instance, on
> +        * RDA8810PL, GPIOC doesn't support interrupt. So we must handle
> +        * those also.
> +        */
> +       rda_gpio->irq = platform_get_irq(pdev, 0);
> +
> +       rda_gpio->base = devm_platform_ioremap_resource(pdev, 0);
> +       if (IS_ERR(rda_gpio->base))
> +               return PTR_ERR(rda_gpio->base);
> +
> +       spin_lock_init(&rda_gpio->lock);
> +
> +       rda_gpio->chip.label = dev_name(&pdev->dev);
> +       rda_gpio->chip.ngpio = ngpios;
> +       rda_gpio->chip.base = -1;
> +       rda_gpio->chip.parent = &pdev->dev;
> +       rda_gpio->chip.of_node = np;
> +       rda_gpio->chip.request = rda_gpio_request;
> +       rda_gpio->chip.free = rda_gpio_free;
> +       rda_gpio->chip.get = rda_gpio_get;
> +       rda_gpio->chip.set = rda_gpio_set;
> +       rda_gpio->chip.direction_input = rda_gpio_direction_input;
> +       rda_gpio->chip.direction_output = rda_gpio_direction_output;
> +
> +       if (rda_gpio->irq >= 0) {
> +               rda_gpio->irq_chip.name = "rda-gpio",
> +               rda_gpio->irq_chip.irq_ack = rda_gpio_irq_ack,
> +               rda_gpio->irq_chip.irq_mask = rda_gpio_irq_mask,
> +               rda_gpio->irq_chip.irq_unmask = rda_gpio_irq_unmask,
> +               rda_gpio->irq_chip.irq_set_type = rda_gpio_irq_set_type,
> +               rda_gpio->irq_chip.flags = IRQCHIP_SKIP_SET_WAKE,
> +
> +               irq = &rda_gpio->chip.irq;
> +               irq->chip = &rda_gpio->irq_chip;
> +               irq->handler = handle_bad_irq;
> +               irq->default_type = IRQ_TYPE_NONE;
> +               irq->parent_handler = rda_gpio_irq_handler;
> +               irq->parent_handler_data = rda_gpio;
> +               irq->num_parents = 1;
> +               irq->parents = &rda_gpio->irq;
> +       }
> +
> +       ret = devm_gpiochip_add_data(&pdev->dev, &rda_gpio->chip, rda_gpio);

I'd simply do 'return devm_gpiochip_add_data()' here, not much else
can fail in this driver's probe.

Bart

> +       if (ret < 0) {
> +               dev_err(&pdev->dev, "Could not register gpiochip %d\n", ret);
> +               return ret;
> +       }
> +
> +       platform_set_drvdata(pdev, rda_gpio);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id rda_gpio_of_match[] = {
> +       { .compatible = "rda,8810pl-gpio", },
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, rda_gpio_of_match);
> +
> +static struct platform_driver rda_gpio_driver = {
> +       .probe = rda_gpio_probe,
> +       .driver = {
> +               .name = "rda-gpio",
> +               .of_match_table = rda_gpio_of_match,
> +       },
> +};
> +
> +module_platform_driver_probe(rda_gpio_driver, rda_gpio_probe);
> +
> +MODULE_DESCRIPTION("RDA Micro GPIO driver");
> +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1
>
Manivannan Sadhasivam Oct. 15, 2019, 4:51 p.m. UTC | #2
Hi Bartosz,

Thanks for the quick review! Please find the reply inline.

On Mon, Oct 14, 2019 at 04:25:29PM +0200, Bartosz Golaszewski wrote:
> niedz., 13 paź 2019 o 13:40 Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> napisał(a):
> >
> > Add support for GPIO controller from RDA Micro.
> 
> Looks nice and clean, just a couple nits.
> 
> >
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/gpio/Kconfig    |   8 +
> >  drivers/gpio/Makefile   |   1 +
> >  drivers/gpio/gpio-rda.c | 334 ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 343 insertions(+)
> >  create mode 100644 drivers/gpio/gpio-rda.c
> >
> > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> > index 38e096e6925f..71826e61fdb3 100644
> > --- a/drivers/gpio/Kconfig
> > +++ b/drivers/gpio/Kconfig
> > @@ -435,6 +435,14 @@ config GPIO_RCAR
> >         help
> >           Say yes here to support GPIO on Renesas R-Car SoCs.
> >
> > +config GPIO_RDA
> > +       bool "RDA Micro GPIO controller support"
> > +       depends on ARCH_RDA || COMPILE_TEST
> > +       depends on OF_GPIO
> > +       select GPIOLIB_IRQCHIP
> > +       help
> > +         Say Y here to support RDA Micro GPIO controller.
> > +
> >  config GPIO_REG
> >         bool
> >         help
> > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> > index d2fd19c15bae..5c68c9a48fa3 100644
> > --- a/drivers/gpio/Makefile
> > +++ b/drivers/gpio/Makefile
> > @@ -115,6 +115,7 @@ obj-$(CONFIG_GPIO_PXA)                      += gpio-pxa.o
> >  obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)     += gpio-raspberrypi-exp.o
> >  obj-$(CONFIG_GPIO_RC5T583)             += gpio-rc5t583.o
> >  obj-$(CONFIG_GPIO_RCAR)                        += gpio-rcar.o
> > +obj-$(CONFIG_GPIO_RDA)                 += gpio-rda.o
> >  obj-$(CONFIG_GPIO_RDC321X)             += gpio-rdc321x.o
> >  obj-$(CONFIG_GPIO_REG)                 += gpio-reg.o
> >  obj-$(CONFIG_ARCH_SA1100)              += gpio-sa1100.o
> > diff --git a/drivers/gpio/gpio-rda.c b/drivers/gpio/gpio-rda.c
> > new file mode 100644
> > index 000000000000..5a4adeb25f72
> > --- /dev/null
> > +++ b/drivers/gpio/gpio-rda.c
> > @@ -0,0 +1,334 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * RDA Micro GPIO driver
> > + *
> > + * Copyright (C) 2012 RDA Micro Inc.
> > + * Copyright (C) 2019 Manivannan Sadhasivam
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/gpio/driver.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/spinlock.h>
> > +
> > +#define RDA_GPIO_OEN_VAL               0x00
> > +#define RDA_GPIO_OEN_SET_OUT           0x04
> > +#define RDA_GPIO_OEN_SET_IN            0x08
> > +#define RDA_GPIO_VAL                   0x0c
> > +#define RDA_GPIO_SET                   0x10
> > +#define RDA_GPIO_CLR                   0x14
> > +#define RDA_GPIO_INT_CTRL_SET          0x18
> > +#define RDA_GPIO_INT_CTRL_CLR          0x1c
> > +#define RDA_GPIO_INT_CLR               0x20
> > +#define RDA_GPIO_INT_STATUS            0x24
> > +
> > +#define RDA_GPIO_IRQ_RISE_SHIFT                0
> > +#define RDA_GPIO_IRQ_FALL_SHIFT                8
> > +#define RDA_GPIO_DEBOUCE_SHIFT         16
> > +#define RDA_GPIO_LEVEL_SHIFT           24
> > +
> > +#define RDA_GPIO_IRQ_MASK              0xff
> > +
> > +/* Each bank consists of 32 GPIOs */
> > +#define RDA_GPIO_BANK_NR       32
> > +
> > +struct rda_gpio {
> > +       struct gpio_chip chip;
> > +       void __iomem *base;
> > +       spinlock_t lock;
> > +       struct irq_chip irq_chip;
> > +       int irq;
> > +};
> > +
> > +static void rda_gpio_update(struct gpio_chip *chip, unsigned int offset,
> > +                           u16 reg, int val)
> > +{
> > +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> > +       void __iomem *base = rda_gpio->base;
> > +       unsigned long flags;
> > +       u32 tmp;
> > +
> > +       spin_lock_irqsave(&rda_gpio->lock, flags);
> > +       tmp = readl_relaxed(base + reg);
> > +
> > +       if (val)
> > +               tmp |= BIT(offset);
> > +       else
> > +               tmp &= ~BIT(offset);
> > +
> > +       writel_relaxed(tmp, base + reg);
> > +       spin_unlock_irqrestore(&rda_gpio->lock, flags);
> > +}
> 
> If you used the mmio regmap, you could save all this code and reuse
> regmap's update helpers. This is just a suggestion, not a requirement
> though.
> 

Agree. I'll post a patch later once this driver gets in.

> > +
> > +static int rda_gpio_request(struct gpio_chip *chip, unsigned int offset)
> > +{
> > +       /* Not supported currently */
> > +       return 0;
> > +}
> > +
> > +static void rda_gpio_free(struct gpio_chip *chip, unsigned int offset)
> > +{
> > +       /* Not supported currently */
> > +}
> 
> Just don't implement these callbacks if they're doing nothing.
> 

Hmm. Since these are some critical callbacks, I thought the drivers should
explicitly expose even not implemented. But I can remove them.

> > +
> > +static int rda_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
> > +{
> > +       rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_IN, 1);
> > +
> > +       return 0;
> > +}
> > +
> > +static int rda_gpio_direction_output(struct gpio_chip *chip,
> > +                                    unsigned int offset, int value)
> > +{
> > +       rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_OUT, 1);
> > +
> > +       return 0;
> > +}
> > +
> > +static int rda_gpio_get(struct gpio_chip *chip, unsigned int offset)
> > +{
> > +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> > +       void __iomem *base = rda_gpio->base;
> > +
> > +       if (readl_relaxed(base + RDA_GPIO_OEN_VAL) & BIT(offset))
> > +               return !!(readl_relaxed(base + RDA_GPIO_VAL) & BIT(offset));
> > +       else
> > +               return !!(readl_relaxed(base + RDA_GPIO_SET) & BIT(offset));
> > +}
> > +
> > +static void rda_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
> > +{
> > +       if (value)
> > +               rda_gpio_update(chip, offset, RDA_GPIO_SET, 1);
> > +       else
> > +               rda_gpio_update(chip, offset, RDA_GPIO_CLR, 1);
> > +}
> > +
> > +static void rda_gpio_irq_mask(struct irq_data *data)
> > +{
> > +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> > +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> > +       void __iomem *base = rda_gpio->base;
> > +       u32 offset = irqd_to_hwirq(data);
> > +       u32 value;
> > +
> > +       value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> > +       value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> > +
> > +       writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> > +}
> > +
> > +static void rda_gpio_irq_ack(struct irq_data *data)
> > +{
> > +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> > +       u32 offset = irqd_to_hwirq(data);
> > +
> > +       rda_gpio_update(chip, offset, RDA_GPIO_INT_CLR, 1);
> > +}
> > +
> > +static int rda_gpio_set_irq(struct gpio_chip *chip, u32 offset,
> > +                           unsigned int flow_type)
> > +{
> > +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> > +       void __iomem *base = rda_gpio->base;
> > +       u32 value;
> > +
> > +       switch (flow_type) {
> > +       case IRQ_TYPE_EDGE_RISING:
> > +               /* Set rising edge trigger */
> > +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> > +
> > +               /* Switch to edge trigger interrupt */
> > +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> > +               break;
> > +
> > +       case IRQ_TYPE_EDGE_FALLING:
> > +               /* Set falling edge trigger */
> > +               value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> > +
> > +               /* Switch to edge trigger interrupt */
> > +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> > +               break;
> > +
> > +       case IRQ_TYPE_EDGE_BOTH:
> > +               /* Set both edge trigger */
> > +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> > +               value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> > +
> > +               /* Switch to edge trigger interrupt */
> > +               value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
> > +               break;
> > +
> > +       case IRQ_TYPE_LEVEL_HIGH:
> > +               /* Set high level trigger */
> > +               value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
> > +
> > +               /* Switch to level trigger interrupt */
> > +               value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> > +               break;
> > +
> > +       case IRQ_TYPE_LEVEL_LOW:
> > +               /* Set low level trigger */
> > +               value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
> > +
> > +               /* Switch to level trigger interrupt */
> > +               value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
> > +               writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
> > +               break;
> > +
> > +       default:
> > +               return -EINVAL;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static void rda_gpio_irq_unmask(struct irq_data *data)
> > +{
> > +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> > +       u32 offset = irqd_to_hwirq(data);
> > +       u32 trigger = irqd_get_trigger_type(data);
> > +
> > +       rda_gpio_set_irq(chip, offset, trigger);
> > +}
> > +
> > +static int rda_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
> > +{
> > +       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> > +       u32 offset = irqd_to_hwirq(data);
> > +       int ret;
> > +
> > +       ret = rda_gpio_set_irq(chip, offset, flow_type);
> > +       if (ret)
> > +               return ret;
> > +
> > +       if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
> > +               irq_set_handler_locked(data, handle_level_irq);
> > +       else if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
> > +               irq_set_handler_locked(data, handle_edge_irq);
> > +
> > +       return 0;
> > +}
> > +
> > +static void rda_gpio_irq_handler(struct irq_desc *desc)
> > +{
> > +       struct gpio_chip *chip = irq_desc_get_handler_data(desc);
> > +       struct irq_chip *ic = irq_desc_get_chip(desc);
> > +       struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
> > +       unsigned long status;
> > +       u32 n, girq;
> > +
> > +       chained_irq_enter(ic, desc);
> > +
> > +       status = readl_relaxed(rda_gpio->base + RDA_GPIO_INT_STATUS);
> > +       /* Only lower 8 bits are capable of generating interrupts */
> > +       status &= RDA_GPIO_IRQ_MASK;
> > +
> > +       for_each_set_bit(n, &status, RDA_GPIO_BANK_NR) {
> > +               girq = irq_find_mapping(chip->irq.domain, n);
> > +               generic_handle_irq(girq);
> > +       }
> > +
> > +       chained_irq_exit(ic, desc);
> > +}
> > +
> > +static int rda_gpio_probe(struct platform_device *pdev)
> > +{
> > +       struct device_node *np = pdev->dev.of_node;
> > +       struct gpio_irq_chip *irq;
> 
> Can you call this variable irq_chip? Visually it interferes with
> rda_gpio->irq too much.
> 

okay.

> > +       struct rda_gpio *rda_gpio;
> > +       u32 ngpios;
> > +       int ret;
> > +
> > +       rda_gpio = devm_kzalloc(&pdev->dev, sizeof(*rda_gpio), GFP_KERNEL);
> > +       if (!rda_gpio)
> > +               return -ENOMEM;
> > +
> > +       ret = of_property_read_u32(np, "ngpios", &ngpios);
> > +       if (ret < 0)
> > +               return ret;
> > +
> 
> Please use the generic device property helpers unless it's really
> necessary to use of_ variants. Also: remove the of_device.h include.
> 

okay.

> > +       /*
> > +        * Not all ports have interrupt capability. For instance, on
> > +        * RDA8810PL, GPIOC doesn't support interrupt. So we must handle
> > +        * those also.
> > +        */
> > +       rda_gpio->irq = platform_get_irq(pdev, 0);
> > +
> > +       rda_gpio->base = devm_platform_ioremap_resource(pdev, 0);
> > +       if (IS_ERR(rda_gpio->base))
> > +               return PTR_ERR(rda_gpio->base);
> > +
> > +       spin_lock_init(&rda_gpio->lock);
> > +
> > +       rda_gpio->chip.label = dev_name(&pdev->dev);
> > +       rda_gpio->chip.ngpio = ngpios;
> > +       rda_gpio->chip.base = -1;
> > +       rda_gpio->chip.parent = &pdev->dev;
> > +       rda_gpio->chip.of_node = np;
> > +       rda_gpio->chip.request = rda_gpio_request;
> > +       rda_gpio->chip.free = rda_gpio_free;
> > +       rda_gpio->chip.get = rda_gpio_get;
> > +       rda_gpio->chip.set = rda_gpio_set;
> > +       rda_gpio->chip.direction_input = rda_gpio_direction_input;
> > +       rda_gpio->chip.direction_output = rda_gpio_direction_output;
> > +
> > +       if (rda_gpio->irq >= 0) {
> > +               rda_gpio->irq_chip.name = "rda-gpio",
> > +               rda_gpio->irq_chip.irq_ack = rda_gpio_irq_ack,
> > +               rda_gpio->irq_chip.irq_mask = rda_gpio_irq_mask,
> > +               rda_gpio->irq_chip.irq_unmask = rda_gpio_irq_unmask,
> > +               rda_gpio->irq_chip.irq_set_type = rda_gpio_irq_set_type,
> > +               rda_gpio->irq_chip.flags = IRQCHIP_SKIP_SET_WAKE,
> > +
> > +               irq = &rda_gpio->chip.irq;
> > +               irq->chip = &rda_gpio->irq_chip;
> > +               irq->handler = handle_bad_irq;
> > +               irq->default_type = IRQ_TYPE_NONE;
> > +               irq->parent_handler = rda_gpio_irq_handler;
> > +               irq->parent_handler_data = rda_gpio;
> > +               irq->num_parents = 1;
> > +               irq->parents = &rda_gpio->irq;
> > +       }
> > +
> > +       ret = devm_gpiochip_add_data(&pdev->dev, &rda_gpio->chip, rda_gpio);
> 
> I'd simply do 'return devm_gpiochip_add_data()' here, not much else
> can fail in this driver's probe.
> 

okay. I'll just move the platform_set_drvdata() call up and return directly.

Thanks,
Mani

> Bart
> 
> > +       if (ret < 0) {
> > +               dev_err(&pdev->dev, "Could not register gpiochip %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       platform_set_drvdata(pdev, rda_gpio);
> > +
> > +       return 0;
> > +}
> > +
> > +static const struct of_device_id rda_gpio_of_match[] = {
> > +       { .compatible = "rda,8810pl-gpio", },
> > +       { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, rda_gpio_of_match);
> > +
> > +static struct platform_driver rda_gpio_driver = {
> > +       .probe = rda_gpio_probe,
> > +       .driver = {
> > +               .name = "rda-gpio",
> > +               .of_match_table = rda_gpio_of_match,
> > +       },
> > +};
> > +
> > +module_platform_driver_probe(rda_gpio_driver, rda_gpio_probe);
> > +
> > +MODULE_DESCRIPTION("RDA Micro GPIO driver");
> > +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.17.1
> >

Patch
diff mbox series

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 38e096e6925f..71826e61fdb3 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -435,6 +435,14 @@  config GPIO_RCAR
 	help
 	  Say yes here to support GPIO on Renesas R-Car SoCs.
 
+config GPIO_RDA
+	bool "RDA Micro GPIO controller support"
+	depends on ARCH_RDA || COMPILE_TEST
+	depends on OF_GPIO
+	select GPIOLIB_IRQCHIP
+	help
+	  Say Y here to support RDA Micro GPIO controller.
+
 config GPIO_REG
 	bool
 	help
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d2fd19c15bae..5c68c9a48fa3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -115,6 +115,7 @@  obj-$(CONFIG_GPIO_PXA)			+= gpio-pxa.o
 obj-$(CONFIG_GPIO_RASPBERRYPI_EXP)	+= gpio-raspberrypi-exp.o
 obj-$(CONFIG_GPIO_RC5T583)		+= gpio-rc5t583.o
 obj-$(CONFIG_GPIO_RCAR)			+= gpio-rcar.o
+obj-$(CONFIG_GPIO_RDA)			+= gpio-rda.o
 obj-$(CONFIG_GPIO_RDC321X)		+= gpio-rdc321x.o
 obj-$(CONFIG_GPIO_REG)			+= gpio-reg.o
 obj-$(CONFIG_ARCH_SA1100)		+= gpio-sa1100.o
diff --git a/drivers/gpio/gpio-rda.c b/drivers/gpio/gpio-rda.c
new file mode 100644
index 000000000000..5a4adeb25f72
--- /dev/null
+++ b/drivers/gpio/gpio-rda.c
@@ -0,0 +1,334 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RDA Micro GPIO driver
+ *
+ * Copyright (C) 2012 RDA Micro Inc.
+ * Copyright (C) 2019 Manivannan Sadhasivam
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define RDA_GPIO_OEN_VAL		0x00
+#define RDA_GPIO_OEN_SET_OUT		0x04
+#define RDA_GPIO_OEN_SET_IN		0x08
+#define RDA_GPIO_VAL			0x0c
+#define RDA_GPIO_SET			0x10
+#define RDA_GPIO_CLR			0x14
+#define RDA_GPIO_INT_CTRL_SET		0x18
+#define RDA_GPIO_INT_CTRL_CLR		0x1c
+#define RDA_GPIO_INT_CLR		0x20
+#define RDA_GPIO_INT_STATUS		0x24
+
+#define RDA_GPIO_IRQ_RISE_SHIFT		0
+#define RDA_GPIO_IRQ_FALL_SHIFT		8
+#define RDA_GPIO_DEBOUCE_SHIFT		16
+#define RDA_GPIO_LEVEL_SHIFT		24
+
+#define RDA_GPIO_IRQ_MASK		0xff
+
+/* Each bank consists of 32 GPIOs */
+#define RDA_GPIO_BANK_NR	32
+
+struct rda_gpio {
+	struct gpio_chip chip;
+	void __iomem *base;
+	spinlock_t lock;
+	struct irq_chip irq_chip;
+	int irq;
+};
+
+static void rda_gpio_update(struct gpio_chip *chip, unsigned int offset,
+			    u16 reg, int val)
+{
+	struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
+	void __iomem *base = rda_gpio->base;
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&rda_gpio->lock, flags);
+	tmp = readl_relaxed(base + reg);
+
+	if (val)
+		tmp |= BIT(offset);
+	else
+		tmp &= ~BIT(offset);
+
+	writel_relaxed(tmp, base + reg);
+	spin_unlock_irqrestore(&rda_gpio->lock, flags);
+}
+
+static int rda_gpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+	/* Not supported currently */
+	return 0;
+}
+
+static void rda_gpio_free(struct gpio_chip *chip, unsigned int offset)
+{
+	/* Not supported currently */
+}
+
+static int rda_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+	rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_IN, 1);
+
+	return 0;
+}
+
+static int rda_gpio_direction_output(struct gpio_chip *chip,
+				     unsigned int offset, int value)
+{
+	rda_gpio_update(chip, offset, RDA_GPIO_OEN_SET_OUT, 1);
+
+	return 0;
+}
+
+static int rda_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
+	void __iomem *base = rda_gpio->base;
+
+	if (readl_relaxed(base + RDA_GPIO_OEN_VAL) & BIT(offset))
+		return !!(readl_relaxed(base + RDA_GPIO_VAL) & BIT(offset));
+	else
+		return !!(readl_relaxed(base + RDA_GPIO_SET) & BIT(offset));
+}
+
+static void rda_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+	if (value)
+		rda_gpio_update(chip, offset, RDA_GPIO_SET, 1);
+	else
+		rda_gpio_update(chip, offset, RDA_GPIO_CLR, 1);
+}
+
+static void rda_gpio_irq_mask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
+	void __iomem *base = rda_gpio->base;
+	u32 offset = irqd_to_hwirq(data);
+	u32 value;
+
+	value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
+	value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
+
+	writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
+}
+
+static void rda_gpio_irq_ack(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	u32 offset = irqd_to_hwirq(data);
+
+	rda_gpio_update(chip, offset, RDA_GPIO_INT_CLR, 1);
+}
+
+static int rda_gpio_set_irq(struct gpio_chip *chip, u32 offset,
+			    unsigned int flow_type)
+{
+	struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
+	void __iomem *base = rda_gpio->base;
+	u32 value;
+
+	switch (flow_type) {
+	case IRQ_TYPE_EDGE_RISING:
+		/* Set rising edge trigger */
+		value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
+
+		/* Switch to edge trigger interrupt */
+		value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		/* Set falling edge trigger */
+		value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
+
+		/* Switch to edge trigger interrupt */
+		value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		/* Set both edge trigger */
+		value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
+		value |= BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
+
+		/* Switch to edge trigger interrupt */
+		value = BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_CLR);
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		/* Set high level trigger */
+		value = BIT(offset) << RDA_GPIO_IRQ_RISE_SHIFT;
+
+		/* Switch to level trigger interrupt */
+		value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		/* Set low level trigger */
+		value = BIT(offset) << RDA_GPIO_IRQ_FALL_SHIFT;
+
+		/* Switch to level trigger interrupt */
+		value |= BIT(offset) << RDA_GPIO_LEVEL_SHIFT;
+		writel_relaxed(value, base + RDA_GPIO_INT_CTRL_SET);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void rda_gpio_irq_unmask(struct irq_data *data)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	u32 offset = irqd_to_hwirq(data);
+	u32 trigger = irqd_get_trigger_type(data);
+
+	rda_gpio_set_irq(chip, offset, trigger);
+}
+
+static int rda_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	u32 offset = irqd_to_hwirq(data);
+	int ret;
+
+	ret = rda_gpio_set_irq(chip, offset, flow_type);
+	if (ret)
+		return ret;
+
+	if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
+		irq_set_handler_locked(data, handle_level_irq);
+	else if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		irq_set_handler_locked(data, handle_edge_irq);
+
+	return 0;
+}
+
+static void rda_gpio_irq_handler(struct irq_desc *desc)
+{
+	struct gpio_chip *chip = irq_desc_get_handler_data(desc);
+	struct irq_chip *ic = irq_desc_get_chip(desc);
+	struct rda_gpio *rda_gpio = gpiochip_get_data(chip);
+	unsigned long status;
+	u32 n, girq;
+
+	chained_irq_enter(ic, desc);
+
+	status = readl_relaxed(rda_gpio->base + RDA_GPIO_INT_STATUS);
+	/* Only lower 8 bits are capable of generating interrupts */
+	status &= RDA_GPIO_IRQ_MASK;
+
+	for_each_set_bit(n, &status, RDA_GPIO_BANK_NR) {
+		girq = irq_find_mapping(chip->irq.domain, n);
+		generic_handle_irq(girq);
+	}
+
+	chained_irq_exit(ic, desc);
+}
+
+static int rda_gpio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct gpio_irq_chip *irq;
+	struct rda_gpio *rda_gpio;
+	u32 ngpios;
+	int ret;
+
+	rda_gpio = devm_kzalloc(&pdev->dev, sizeof(*rda_gpio), GFP_KERNEL);
+	if (!rda_gpio)
+		return -ENOMEM;
+
+	ret = of_property_read_u32(np, "ngpios", &ngpios);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Not all ports have interrupt capability. For instance, on
+	 * RDA8810PL, GPIOC doesn't support interrupt. So we must handle
+	 * those also.
+	 */
+	rda_gpio->irq = platform_get_irq(pdev, 0);
+
+	rda_gpio->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(rda_gpio->base))
+		return PTR_ERR(rda_gpio->base);
+
+	spin_lock_init(&rda_gpio->lock);
+
+	rda_gpio->chip.label = dev_name(&pdev->dev);
+	rda_gpio->chip.ngpio = ngpios;
+	rda_gpio->chip.base = -1;
+	rda_gpio->chip.parent = &pdev->dev;
+	rda_gpio->chip.of_node = np;
+	rda_gpio->chip.request = rda_gpio_request;
+	rda_gpio->chip.free = rda_gpio_free;
+	rda_gpio->chip.get = rda_gpio_get;
+	rda_gpio->chip.set = rda_gpio_set;
+	rda_gpio->chip.direction_input = rda_gpio_direction_input;
+	rda_gpio->chip.direction_output = rda_gpio_direction_output;
+
+	if (rda_gpio->irq >= 0) {
+		rda_gpio->irq_chip.name = "rda-gpio",
+		rda_gpio->irq_chip.irq_ack = rda_gpio_irq_ack,
+		rda_gpio->irq_chip.irq_mask = rda_gpio_irq_mask,
+		rda_gpio->irq_chip.irq_unmask = rda_gpio_irq_unmask,
+		rda_gpio->irq_chip.irq_set_type = rda_gpio_irq_set_type,
+		rda_gpio->irq_chip.flags = IRQCHIP_SKIP_SET_WAKE,
+
+		irq = &rda_gpio->chip.irq;
+		irq->chip = &rda_gpio->irq_chip;
+		irq->handler = handle_bad_irq;
+		irq->default_type = IRQ_TYPE_NONE;
+		irq->parent_handler = rda_gpio_irq_handler;
+		irq->parent_handler_data = rda_gpio;
+		irq->num_parents = 1;
+		irq->parents = &rda_gpio->irq;
+	}
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &rda_gpio->chip, rda_gpio);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not register gpiochip %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, rda_gpio);
+
+	return 0;
+}
+
+static const struct of_device_id rda_gpio_of_match[] = {
+	{ .compatible = "rda,8810pl-gpio", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rda_gpio_of_match);
+
+static struct platform_driver rda_gpio_driver = {
+	.probe = rda_gpio_probe,
+	.driver = {
+		.name = "rda-gpio",
+		.of_match_table	= rda_gpio_of_match,
+	},
+};
+
+module_platform_driver_probe(rda_gpio_driver, rda_gpio_probe);
+
+MODULE_DESCRIPTION("RDA Micro GPIO driver");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_LICENSE("GPL v2");