pinctrl: nsp: add gpio-a driver support for Broadcom NSP SoC
authorYendapally Reddy Dhananjaya Reddy <yrdreddy@broadcom.com>
Fri, 4 Dec 2015 17:11:42 +0000 (12:11 -0500)
committerLinus Walleij <linus.walleij@linaro.org>
Thu, 10 Dec 2015 17:44:59 +0000 (18:44 +0100)
This adds the initial support of the Broadcom NSP gpio-a driver.

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yrdreddy@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
drivers/pinctrl/bcm/Kconfig
drivers/pinctrl/bcm/Makefile
drivers/pinctrl/bcm/pinctrl-nsp-gpio.c [new file with mode: 0644]

index cd11d4d9ad58f86c719eca0193c9fe08ffd16f21..1a8c837205519470bf032c2f3633b77393bd7263 100644 (file)
@@ -54,3 +54,20 @@ config PINCTRL_CYGNUS_MUX
          The Broadcom Cygnus IOMUX driver supports group based IOMUX
          configuration, with the exception that certain individual pins
          can be overrided to GPIO function
+
+config PINCTRL_NSP_GPIO
+       bool "Broadcom NSP GPIO (with PINCONF) driver"
+       depends on OF_GPIO && (ARCH_BCM_NSP || COMPILE_TEST)
+       select GPIOLIB_IRQCHIP
+       select PINCONF
+       select GENERIC_PINCONF
+       default ARCH_BCM_NSP
+       help
+         Say yes here to enable the Broadcom NSP GPIO driver.
+
+         The Broadcom Northstar Plus SoC ChipcommonA GPIO controller is
+         supported by this driver.
+
+         The ChipcommonA GPIO controller support basic PINCONF functions such
+         as bias pull up, pull down, and drive strength configurations, when
+         these pins are muxed to GPIO.
index 2b2f70ee804ccd607703a42698027f3435b9c760..2fb1ed85b7376ea068f87c9d2a17bb267dd186b3 100644 (file)
@@ -4,3 +4,4 @@ obj-$(CONFIG_PINCTRL_BCM281XX)          += pinctrl-bcm281xx.o
 obj-$(CONFIG_PINCTRL_BCM2835)          += pinctrl-bcm2835.o
 obj-$(CONFIG_PINCTRL_CYGNUS_GPIO)      += pinctrl-cygnus-gpio.o
 obj-$(CONFIG_PINCTRL_CYGNUS_MUX)       += pinctrl-cygnus-mux.o
+obj-$(CONFIG_PINCTRL_NSP_GPIO)         += pinctrl-nsp-gpio.o
diff --git a/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c b/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c
new file mode 100644 (file)
index 0000000..06b7aaf
--- /dev/null
@@ -0,0 +1,749 @@
+/*
+ * Copyright (C) 2015 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * This file contains the Broadcom Northstar Plus (NSP) GPIO driver that
+ * supports the chipCommonA GPIO controller. Basic PINCONF such as bias,
+ * pull up/down, slew and drive strength are also supported in this driver.
+ *
+ * Pins from the chipCommonA  GPIO can be individually muxed to GPIO function,
+ * through the interaction with the NSP IOMUX controller.
+ */
+
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/slab.h>
+
+#include "../pinctrl-utils.h"
+
+#define NSP_CHIP_A_INT_STATUS          0x00
+#define NSP_CHIP_A_INT_MASK            0x04
+#define NSP_GPIO_DATA_IN               0x40
+#define NSP_GPIO_DATA_OUT              0x44
+#define NSP_GPIO_OUT_EN                        0x48
+#define NSP_GPIO_INT_POLARITY          0x50
+#define NSP_GPIO_INT_MASK              0x54
+#define NSP_GPIO_EVENT                 0x58
+#define NSP_GPIO_EVENT_INT_MASK                0x5c
+#define NSP_GPIO_EVENT_INT_POLARITY    0x64
+#define NSP_CHIP_A_GPIO_INT_BIT                0x01
+
+/* I/O parameters offset for chipcommon A GPIO */
+#define NSP_GPIO_DRV_CTRL              0x00
+#define NSP_GPIO_HYSTERESIS_EN         0x10
+#define NSP_GPIO_SLEW_RATE_EN          0x14
+#define NSP_PULL_UP_EN                 0x18
+#define NSP_PULL_DOWN_EN               0x1c
+#define GPIO_DRV_STRENGTH_BITS         0x03
+
+/*
+ * nsp GPIO core
+ *
+ * @dev: pointer to device
+ * @base: I/O register base for nsp GPIO controller
+ * @io_ctrl: I/O register base for PINCONF support outside the GPIO block
+ * @gc: GPIO chip
+ * @pctl: pointer to pinctrl_dev
+ * @pctldesc: pinctrl descriptor
+ * @irq_domain: pointer to irq domain
+ * @lock: lock to protect access to I/O registers
+ */
+struct nsp_gpio {
+       struct device *dev;
+       void __iomem *base;
+       void __iomem *io_ctrl;
+       struct gpio_chip gc;
+       struct pinctrl_dev *pctl;
+       struct pinctrl_desc pctldesc;
+       struct irq_domain *irq_domain;
+       spinlock_t lock;
+};
+
+enum base_type {
+       REG,
+       IO_CTRL
+};
+
+static inline struct nsp_gpio *to_nsp_gpio(struct gpio_chip *gc)
+{
+       return container_of(gc, struct nsp_gpio, gc);
+}
+
+/*
+ * Mapping from PINCONF pins to GPIO pins is 1-to-1
+ */
+static inline unsigned nsp_pin_to_gpio(unsigned pin)
+{
+       return pin;
+}
+
+/*
+ *  nsp_set_bit - set or clear one bit (corresponding to the GPIO pin) in a
+ *  nsp GPIO register
+ *
+ *  @nsp_gpio: nsp GPIO device
+ *  @base_type: reg base to modify
+ *  @reg: register offset
+ *  @gpio: GPIO pin
+ *  @set: set or clear
+ */
+static inline void nsp_set_bit(struct nsp_gpio *chip, enum base_type address,
+                              unsigned int reg, unsigned gpio, bool set)
+{
+       u32 val;
+       void __iomem *base_address;
+
+       if (address == IO_CTRL)
+               base_address = chip->io_ctrl;
+       else
+               base_address = chip->base;
+
+       val = readl(base_address + reg);
+       if (set)
+               val |= BIT(gpio);
+       else
+               val &= ~BIT(gpio);
+
+       writel(val, base_address + reg);
+}
+
+/*
+ *  nsp_get_bit - get one bit (corresponding to the GPIO pin) in a
+ *  nsp GPIO register
+ */
+static inline bool nsp_get_bit(struct nsp_gpio *chip, enum base_type address,
+                              unsigned int reg, unsigned gpio)
+{
+       if (address == IO_CTRL)
+               return !!(readl(chip->io_ctrl + reg) & BIT(gpio));
+       else
+               return !!(readl(chip->base + reg) & BIT(gpio));
+}
+
+static irqreturn_t nsp_gpio_irq_handler(int irq, void *data)
+{
+       struct nsp_gpio *chip = (struct nsp_gpio *)data;
+       struct gpio_chip gc = chip->gc;
+       int bit;
+       unsigned long int_bits = 0;
+       u32 int_status;
+
+       /* go through the entire GPIOs and handle all interrupts */
+       int_status = readl(chip->base + NSP_CHIP_A_INT_STATUS);
+       if (int_status & NSP_CHIP_A_GPIO_INT_BIT) {
+               unsigned int event, level;
+
+               /* Get level and edge interrupts */
+               event = readl(chip->base + NSP_GPIO_EVENT_INT_MASK) &
+                             readl(chip->base + NSP_GPIO_EVENT);
+               level = readl(chip->base + NSP_GPIO_DATA_IN) ^
+                             readl(chip->base + NSP_GPIO_INT_POLARITY);
+               level &= readl(chip->base + NSP_GPIO_INT_MASK);
+               int_bits = level | event;
+
+               for_each_set_bit(bit, &int_bits, gc.ngpio) {
+                       /*
+                        * Clear the interrupt before invoking the
+                        * handler, so we do not leave any window
+                        */
+                       writel(BIT(bit), chip->base + NSP_GPIO_EVENT);
+                       generic_handle_irq(
+                               irq_linear_revmap(chip->irq_domain, bit));
+               }
+       }
+
+       return  int_bits ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void nsp_gpio_irq_ack(struct irq_data *d)
+{
+       struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
+       unsigned gpio = d->hwirq;
+       u32 val = BIT(gpio);
+       u32 trigger_type;
+
+       trigger_type = irq_get_trigger_type(d->irq);
+       if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+               nsp_set_bit(chip, REG, NSP_GPIO_EVENT, gpio, val);
+}
+
+/*
+ *  nsp_gpio_irq_set_mask - mask/unmask a GPIO interrupt
+ *
+ *  @d: IRQ chip data
+ *  @unmask: mask/unmask GPIO interrupt
+ */
+static void nsp_gpio_irq_set_mask(struct irq_data *d, bool unmask)
+{
+       struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
+       unsigned gpio = d->hwirq;
+       u32 trigger_type;
+
+       trigger_type = irq_get_trigger_type(d->irq);
+       if (trigger_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+               nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_MASK, gpio, unmask);
+       else
+               nsp_set_bit(chip, REG, NSP_GPIO_INT_MASK, gpio, unmask);
+}
+
+static void nsp_gpio_irq_mask(struct irq_data *d)
+{
+       struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_gpio_irq_set_mask(d, false);
+       spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static void nsp_gpio_irq_unmask(struct irq_data *d)
+{
+       struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_gpio_irq_set_mask(d, true);
+       spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+       struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
+       unsigned gpio = d->hwirq;
+       bool level_low;
+       bool falling;
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       falling = nsp_get_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio);
+       level_low = nsp_get_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio);
+
+       switch (type & IRQ_TYPE_SENSE_MASK) {
+       case IRQ_TYPE_EDGE_RISING:
+               falling = false;
+               break;
+
+       case IRQ_TYPE_EDGE_FALLING:
+               falling = true;
+               break;
+
+       case IRQ_TYPE_LEVEL_HIGH:
+               level_low = false;
+               break;
+
+       case IRQ_TYPE_LEVEL_LOW:
+               level_low = true;
+               break;
+
+       default:
+               dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
+                       type);
+               spin_unlock_irqrestore(&chip->lock, flags);
+               return -EINVAL;
+       }
+
+       nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio, falling);
+       nsp_set_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio, level_low);
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       dev_dbg(chip->dev, "gpio:%u level_low:%s falling:%s\n", gpio,
+               level_low ? "true" : "false", falling ? "true" : "false");
+       return 0;
+}
+
+static struct irq_chip nsp_gpio_irq_chip = {
+       .name = "gpio-a",
+       .irq_enable = nsp_gpio_irq_unmask,
+       .irq_disable = nsp_gpio_irq_mask,
+       .irq_ack = nsp_gpio_irq_ack,
+       .irq_mask = nsp_gpio_irq_mask,
+       .irq_unmask = nsp_gpio_irq_unmask,
+       .irq_set_type = nsp_gpio_irq_set_type,
+};
+
+/*
+ * Request the nsp IOMUX pinmux controller to mux individual pins to GPIO
+ */
+static int nsp_gpio_request(struct gpio_chip *gc, unsigned offset)
+{
+       unsigned gpio = gc->base + offset;
+
+       return pinctrl_request_gpio(gpio);
+}
+
+static void nsp_gpio_free(struct gpio_chip *gc, unsigned offset)
+{
+       unsigned gpio = gc->base + offset;
+
+       pinctrl_free_gpio(gpio);
+}
+
+static int nsp_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
+{
+       struct nsp_gpio *chip = to_nsp_gpio(gc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, false);
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
+       return 0;
+}
+
+static int nsp_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
+                                    int val)
+{
+       struct nsp_gpio *chip = to_nsp_gpio(gc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, true);
+       nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
+       return 0;
+}
+
+static void nsp_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
+{
+       struct nsp_gpio *chip = to_nsp_gpio(gc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
+}
+
+static int nsp_gpio_get(struct gpio_chip *gc, unsigned gpio)
+{
+       struct nsp_gpio *chip = to_nsp_gpio(gc);
+
+       return !!(readl(chip->base + NSP_GPIO_DATA_IN) & BIT(gpio));
+}
+
+static int nsp_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+       struct nsp_gpio *chip = to_nsp_gpio(gc);
+
+       return irq_linear_revmap(chip->irq_domain, offset);
+}
+
+static int nsp_get_groups_count(struct pinctrl_dev *pctldev)
+{
+       return 1;
+}
+
+/*
+ * Only one group: "gpio_grp", since this local pinctrl device only performs
+ * GPIO specific PINCONF configurations
+ */
+static const char *nsp_get_group_name(struct pinctrl_dev *pctldev,
+                                     unsigned selector)
+{
+       return "gpio_grp";
+}
+
+static const struct pinctrl_ops nsp_pctrl_ops = {
+       .get_groups_count = nsp_get_groups_count,
+       .get_group_name = nsp_get_group_name,
+       .dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+       .dt_free_map = pinctrl_utils_dt_free_map,
+};
+
+static int nsp_gpio_set_slew(struct nsp_gpio *chip, unsigned gpio, u16 slew)
+{
+       if (slew)
+               nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, true);
+       else
+               nsp_set_bit(chip, IO_CTRL, NSP_GPIO_SLEW_RATE_EN, gpio, false);
+
+       return 0;
+}
+
+static int nsp_gpio_set_pull(struct nsp_gpio *chip, unsigned gpio,
+                            bool pull_up, bool pull_down)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       nsp_set_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio, pull_down);
+       nsp_set_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio, pull_up);
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       dev_dbg(chip->dev, "gpio:%u set pullup:%d pulldown: %d\n",
+               gpio, pull_up, pull_down);
+       return 0;
+}
+
+static void nsp_gpio_get_pull(struct nsp_gpio *chip, unsigned gpio,
+                             bool *pull_up, bool *pull_down)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       *pull_up = nsp_get_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio);
+       *pull_down = nsp_get_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio);
+       spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
+                                u16 strength)
+{
+       u32 offset, shift, i;
+       u32 val;
+       unsigned long flags;
+
+       /* make sure drive strength is supported */
+       if (strength < 2 || strength > 16 || (strength % 2))
+               return -ENOTSUPP;
+
+       shift = gpio;
+       offset = NSP_GPIO_DRV_CTRL;
+       dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
+               strength);
+       spin_lock_irqsave(&chip->lock, flags);
+       strength = (strength / 2) - 1;
+       for (i = GPIO_DRV_STRENGTH_BITS; i > 0; i--) {
+               val = readl(chip->io_ctrl + offset);
+               val &= ~BIT(shift);
+               val |= ((strength >> (i-1)) & 0x1) << shift;
+               writel(val, chip->io_ctrl + offset);
+               offset += 4;
+       }
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       return 0;
+}
+
+static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio,
+                                u16 *strength)
+{
+       unsigned int i, offset, shift;
+       u32 val;
+       unsigned long flags;
+
+       offset = NSP_GPIO_DRV_CTRL;
+       shift = gpio;
+
+       spin_lock_irqsave(&chip->lock, flags);
+       *strength = 0;
+       for (i = (GPIO_DRV_STRENGTH_BITS - 1); i >= 0; i--) {
+               val = readl(chip->io_ctrl + offset) & BIT(shift);
+               val >>= shift;
+               *strength += (val << i);
+               offset += 4;
+       }
+
+       /* convert to mA */
+       *strength = (*strength + 1) * 2;
+       spin_unlock_irqrestore(&chip->lock, flags);
+
+       return 0;
+}
+
+int nsp_pin_config_group_get(struct pinctrl_dev *pctldev, unsigned selector,
+                            unsigned long *config)
+{
+       return 0;
+}
+
+int nsp_pin_config_group_set(struct pinctrl_dev *pctldev, unsigned selector,
+                            unsigned long *configs, unsigned num_configs)
+{
+       return 0;
+}
+
+static int nsp_pin_config_get(struct pinctrl_dev *pctldev, unsigned pin,
+                             unsigned long *config)
+{
+       struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
+       enum pin_config_param param = pinconf_to_config_param(*config);
+       unsigned int gpio;
+       u16 arg = 0;
+       bool pull_up, pull_down;
+       int ret;
+
+       gpio = nsp_pin_to_gpio(pin);
+       switch (param) {
+       case PIN_CONFIG_BIAS_DISABLE:
+               nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
+               if ((pull_up == false) && (pull_down == false))
+                       return 0;
+               else
+                       return -EINVAL;
+
+       case PIN_CONFIG_BIAS_PULL_UP:
+               nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
+               if (pull_up)
+                       return 0;
+               else
+                       return -EINVAL;
+
+       case PIN_CONFIG_BIAS_PULL_DOWN:
+               nsp_gpio_get_pull(chip, gpio, &pull_up, &pull_down);
+               if (pull_down)
+                       return 0;
+               else
+                       return -EINVAL;
+
+       case PIN_CONFIG_DRIVE_STRENGTH:
+               ret = nsp_gpio_get_strength(chip, gpio, &arg);
+               if (ret)
+                       return ret;
+               *config = pinconf_to_config_packed(param, arg);
+               return 0;
+
+       default:
+               return -ENOTSUPP;
+       }
+}
+
+static int nsp_pin_config_set(struct pinctrl_dev *pctldev, unsigned pin,
+                             unsigned long *configs, unsigned num_configs)
+{
+       struct nsp_gpio *chip = pinctrl_dev_get_drvdata(pctldev);
+       enum pin_config_param param;
+       u16 arg;
+       unsigned int i, gpio;
+       int ret = -ENOTSUPP;
+
+       gpio = nsp_pin_to_gpio(pin);
+       for (i = 0; i < num_configs; i++) {
+               param = pinconf_to_config_param(configs[i]);
+               arg = pinconf_to_config_argument(configs[i]);
+
+               switch (param) {
+               case PIN_CONFIG_BIAS_DISABLE:
+                       ret = nsp_gpio_set_pull(chip, gpio, false, false);
+                       if (ret < 0)
+                               goto out;
+                       break;
+
+               case PIN_CONFIG_BIAS_PULL_UP:
+                       ret = nsp_gpio_set_pull(chip, gpio, true, false);
+                       if (ret < 0)
+                               goto out;
+                       break;
+
+               case PIN_CONFIG_BIAS_PULL_DOWN:
+                       ret = nsp_gpio_set_pull(chip, gpio, false, true);
+                       if (ret < 0)
+                               goto out;
+                       break;
+
+               case PIN_CONFIG_DRIVE_STRENGTH:
+                       ret = nsp_gpio_set_strength(chip, gpio, arg);
+                       if (ret < 0)
+                               goto out;
+                       break;
+
+               case PIN_CONFIG_SLEW_RATE:
+                       ret = nsp_gpio_set_slew(chip, gpio, arg);
+                       if (ret < 0)
+                               goto out;
+                       break;
+
+               default:
+                       dev_err(chip->dev, "invalid configuration\n");
+                       return -ENOTSUPP;
+               }
+       }
+
+out:
+       return ret;
+}
+
+static const struct pinconf_ops nsp_pconf_ops = {
+       .is_generic = true,
+       .pin_config_get = nsp_pin_config_get,
+       .pin_config_set = nsp_pin_config_set,
+       .pin_config_group_get = nsp_pin_config_group_get,
+       .pin_config_group_set = nsp_pin_config_group_set,
+};
+
+/*
+ * NSP GPIO controller supports some PINCONF related configurations such as
+ * pull up, pull down, slew and drive strength, when the pin is configured
+ * to GPIO.
+ *
+ * Here a local pinctrl device is created with simple 1-to-1 pin mapping to the
+ * local GPIO pins
+ */
+static int nsp_gpio_register_pinconf(struct nsp_gpio *chip)
+{
+       struct pinctrl_desc *pctldesc = &chip->pctldesc;
+       struct pinctrl_pin_desc *pins;
+       struct gpio_chip *gc = &chip->gc;
+       int i;
+
+       pins = devm_kcalloc(chip->dev, gc->ngpio, sizeof(*pins), GFP_KERNEL);
+       if (!pins)
+               return -ENOMEM;
+       for (i = 0; i < gc->ngpio; i++) {
+               pins[i].number = i;
+               pins[i].name = devm_kasprintf(chip->dev, GFP_KERNEL,
+                                             "gpio-%d", i);
+               if (!pins[i].name)
+                       return -ENOMEM;
+       }
+       pctldesc->name = dev_name(chip->dev);
+       pctldesc->pctlops = &nsp_pctrl_ops;
+       pctldesc->pins = pins;
+       pctldesc->npins = gc->ngpio;
+       pctldesc->confops = &nsp_pconf_ops;
+
+       chip->pctl = pinctrl_register(pctldesc, chip->dev, chip);
+       if (IS_ERR(chip->pctl)) {
+               dev_err(chip->dev, "unable to register pinctrl device\n");
+               return PTR_ERR(chip->pctl);
+       }
+
+       return 0;
+}
+
+static const struct of_device_id nsp_gpio_of_match[] = {
+       {.compatible = "brcm,nsp-gpio-a",},
+       {}
+};
+
+static int nsp_gpio_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct resource *res;
+       struct nsp_gpio *chip;
+       struct gpio_chip *gc;
+       u32 val, count;
+       int irq, ret;
+
+       if (of_property_read_u32(pdev->dev.of_node, "ngpios", &val)) {
+               dev_err(&pdev->dev, "Missing ngpios OF property\n");
+               return -ENODEV;
+       }
+
+       chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       chip->dev = dev;
+       platform_set_drvdata(pdev, chip);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       chip->base = devm_ioremap_resource(dev, res);
+       if (IS_ERR(chip->base)) {
+               dev_err(dev, "unable to map I/O memory\n");
+               return PTR_ERR(chip->base);
+       }
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       chip->io_ctrl = devm_ioremap_resource(dev, res);
+       if (IS_ERR(chip->io_ctrl)) {
+               dev_err(dev, "unable to map I/O memory\n");
+               return PTR_ERR(chip->io_ctrl);
+       }
+
+       spin_lock_init(&chip->lock);
+       gc = &chip->gc;
+       gc->base = -1;
+       gc->can_sleep = false;
+       gc->ngpio = val;
+       gc->label = dev_name(dev);
+       gc->dev = dev;
+       gc->of_node = dev->of_node;
+       gc->request = nsp_gpio_request;
+       gc->free = nsp_gpio_free;
+       gc->direction_input = nsp_gpio_direction_input;
+       gc->direction_output = nsp_gpio_direction_output;
+       gc->set = nsp_gpio_set;
+       gc->get = nsp_gpio_get;
+       gc->to_irq = nsp_gpio_to_irq;
+
+       /* optional GPIO interrupt support */
+       irq = platform_get_irq(pdev, 0);
+       if (irq > 0) {
+               /* Create irq domain so that each pin can be assigned an IRQ.*/
+               chip->irq_domain = irq_domain_add_linear(gc->of_node, gc->ngpio,
+                                                        &irq_domain_simple_ops,
+                                                        chip);
+               if (!chip->irq_domain) {
+                       dev_err(&pdev->dev, "Couldn't allocate IRQ domain\n");
+                       return -ENXIO;
+               }
+
+               /* Map each gpio to an IRQ and set the handler for gpiolib. */
+               for (count = 0; count < gc->ngpio; count++) {
+                       int irq = irq_create_mapping(chip->irq_domain, count);
+
+                       irq_set_chip_and_handler(irq, &nsp_gpio_irq_chip,
+                                                handle_simple_irq);
+                       set_irq_flags(irq, IRQF_VALID);
+                       irq_set_chip_data(irq, chip);
+               }
+
+               /* Install ISR for this GPIO controller. */
+               ret = devm_request_irq(&pdev->dev, irq, nsp_gpio_irq_handler,
+                                      IRQF_SHARED, "gpio-a", chip);
+               if (ret) {
+                       dev_err(&pdev->dev, "Unable to request IRQ%d: %d\n",
+                               irq, ret);
+                       goto err_rm_gpiochip;
+               }
+
+               val = readl(chip->base + NSP_CHIP_A_INT_MASK);
+               val = val | NSP_CHIP_A_GPIO_INT_BIT;
+               writel(val, (chip->base + NSP_CHIP_A_INT_MASK));
+       }
+
+       ret = gpiochip_add(gc);
+       if (ret < 0) {
+               dev_err(dev, "unable to add GPIO chip\n");
+               return ret;
+       }
+
+       ret = nsp_gpio_register_pinconf(chip);
+       if (ret) {
+               dev_err(dev, "unable to register pinconf\n");
+               goto err_rm_gpiochip;
+       }
+
+       return 0;
+
+err_rm_gpiochip:
+       gpiochip_remove(gc);
+
+       return ret;
+}
+
+static struct platform_driver nsp_gpio_driver = {
+       .driver = {
+               .name = "nsp-gpio-a",
+               .of_match_table = nsp_gpio_of_match,
+       },
+       .probe = nsp_gpio_probe,
+};
+
+static int __init nsp_gpio_init(void)
+{
+       return platform_driver_probe(&nsp_gpio_driver, nsp_gpio_probe);
+}
+arch_initcall_sync(nsp_gpio_init);