/*
* Xilinx Zynq GPIO device driver
*
* Copyright (C) 2009 - 2014 Xilinx, Inc.
*
* 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; either version 2 of the License, or (at your option) any later
* version.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#define DRIVER_NAME "zynq-gpio"
/* Maximum banks */
#define ZYNQ_GPIO_MAX_BANK 4
#define ZYNQ_GPIO_BANK0_NGPIO 32
#define ZYNQ_GPIO_BANK1_NGPIO 22
#define ZYNQ_GPIO_BANK2_NGPIO 32
#define ZYNQ_GPIO_BANK3_NGPIO 32
#define ZYNQ_GPIO_NR_GPIOS (ZYNQ_GPIO_BANK0_NGPIO + \
ZYNQ_GPIO_BANK1_NGPIO + \
ZYNQ_GPIO_BANK2_NGPIO + \
ZYNQ_GPIO_BANK3_NGPIO)
#define ZYNQ_GPIO_BANK0_PIN_MIN 0
#define ZYNQ_GPIO_BANK0_PIN_MAX (ZYNQ_GPIO_BANK0_PIN_MIN + \
ZYNQ_GPIO_BANK0_NGPIO - 1)
#define ZYNQ_GPIO_BANK1_PIN_MIN (ZYNQ_GPIO_BANK0_PIN_MAX + 1)
#define ZYNQ_GPIO_BANK1_PIN_MAX (ZYNQ_GPIO_BANK1_PIN_MIN + \
ZYNQ_GPIO_BANK1_NGPIO - 1)
#define ZYNQ_GPIO_BANK2_PIN_MIN (ZYNQ_GPIO_BANK1_PIN_MAX + 1)
#define ZYNQ_GPIO_BANK2_PIN_MAX (ZYNQ_GPIO_BANK2_PIN_MIN + \
ZYNQ_GPIO_BANK2_NGPIO - 1)
#define ZYNQ_GPIO_BANK3_PIN_MIN (ZYNQ_GPIO_BANK2_PIN_MAX + 1)
#define ZYNQ_GPIO_BANK3_PIN_MAX (ZYNQ_GPIO_BANK3_PIN_MIN + \
ZYNQ_GPIO_BANK3_NGPIO - 1)
/* Register offsets for the GPIO device */
/* LSW Mask & Data -WO */
#define ZYNQ_GPIO_DATA_LSW_OFFSET(BANK) (0x000 + (8 * BANK))
/* MSW Mask & Data -WO */
#define ZYNQ_GPIO_DATA_MSW_OFFSET(BANK) (0x004 + (8 * BANK))
/* Data Register-RW */
#define ZYNQ_GPIO_DATA_RO_OFFSET(BANK) (0x060 + (4 * BANK))
/* Direction mode reg-RW */
#define ZYNQ_GPIO_DIRM_OFFSET(BANK) (0x204 + (0x40 * BANK))
/* Output enable reg-RW */
#define ZYNQ_GPIO_OUTEN_OFFSET(BANK) (0x208 + (0x40 * BANK))
/* Interrupt mask reg-RO */
#define ZYNQ_GPIO_INTMASK_OFFSET(BANK) (0x20C + (0x40 * BANK))
/* Interrupt enable reg-WO */
#define ZYNQ_GPIO_INTEN_OFFSET(BANK) (0x210 + (0x40 * BANK))
/* Interrupt disable reg-WO */
#define ZYNQ_GPIO_INTDIS_OFFSET(BANK) (0x214 + (0x40 * BANK))
/* Interrupt status reg-RO */
#define ZYNQ_GPIO_INTSTS_OFFSET(BANK) (0x218 + (0x40 * BANK))
/* Interrupt type reg-RW */
#define ZYNQ_GPIO_INTTYPE_OFFSET(BANK) (0x21C + (0x40 * BANK))
/* Interrupt polarity reg-RW */
#define ZYNQ_GPIO_INTPOL_OFFSET(BANK) (0x220 + (0x40 * BANK))
/* Interrupt on any, reg-RW */
#define ZYNQ_GPIO_INTANY_OFFSET(BANK) (0x224 + (0x40 * BANK))
/* Disable all interrupts mask */
#define ZYNQ_GPIO_IXR_DISABLE_ALL 0xFFFFFFFF
/* Mid pin number of a bank */
#define ZYNQ_GPIO_MID_PIN_NUM 16
/* GPIO upper 16 bit mask */
#define ZYNQ_GPIO_UPPER_MASK 0xFFFF0000
/**
* struct zynq_gpio - gpio device private data structure
* @chip: instance of the gpio_chip
* @base_addr: base address of the GPIO device
* @clk: clock resource for this controller
*/
struct zynq_gpio {
struct gpio_chip chip;
void __iomem *base_addr;
struct clk *clk;
};
/**
* zynq_gpio_get_bank_pin - Get the bank number and pin number within that bank
* for a given pin in the GPIO device
* @pin_num: gpio pin number within the device
* @bank_num: an output parameter used to return the bank number of the gpio
* pin
* @bank_pin_num: an output parameter used to return pin number within a bank
* for the given gpio pin
*
* Returns the bank number and pin offset within the bank.
*/
static inline void zynq_gpio_get_bank_pin(unsigned int pin_num,
unsigned int *bank_num,
unsigned int *bank_pin_num)
{
switch (pin_num) {
case ZYNQ_GPIO_BANK0_PIN_MIN ... ZYNQ_GPIO_BANK0_PIN_MAX:
*bank_num = 0;
*bank_pin_num = pin_num;
break;
case ZYNQ_GPIO_BANK1_PIN_MIN ... ZYNQ_GPIO_BANK1_PIN_MAX:
*bank_num = 1;
*bank_pin_num = pin_num - ZYNQ_GPIO_BANK1_PIN_MIN;
break;
case ZYNQ_GPIO_BANK2_PIN_MIN ... ZYNQ_GPIO_BANK2_PIN_MAX:
*bank_num = 2;
*bank_pin_num = pin_num - ZYNQ_GPIO_BANK2_PIN_MIN;
break;
case ZYNQ_GPIO_BANK3_PIN_MIN ... ZYNQ_GPIO_BANK3_PIN_MAX:
*bank_num = 3;
*bank_pin_num = pin_num - ZYNQ_GPIO_BANK3_PIN_MIN;
break;
default:
WARN(true, "invalid GPIO pin number: %u", pin_num);
*bank_num = 0;
*bank_pin_num = 0;
break;
}
}
/**
* zynq_gpio_get_value - Get the state of the specified pin of GPIO device
* @chip: gpio_chip instance to be worked on
* @pin: gpio pin number within the device
*
* This function reads the state of the specified pin of the GPIO device.
*
* Return: 0 if the pin is low, 1 if pin is high.
*/
static int zynq_gpio_get_value(struct gpio_chip *chip, unsigned int pin)
{
u32 data;
unsigned int bank_num, bank_pin_num;
struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
data = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
return (data >> bank_pin_num) & 1;
}
/**
* zynq_gpio_set_value - Modify the state of the pin with specified value
* @chip: gpio_chip instance to be worked on
* @pin: gpio pin number within the device
* @state: value used to modify the state of the specified pin
*
* This function calculates the register offset (i.e to lower 16 bits or
* upper 16 bits) based on the given pin number and sets the state of a
* gpio pin to the specified value. The state is either 0 or non-zero.
*/
static void zynq_gpio_set_value(struct gpio_chip *chip, unsigned int pin,
int state)
{
unsigned int reg_offset, bank_num, bank_pin_num;
struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
if (bank_pin_num >= ZYNQ_GPIO_MID_PIN_NUM) {
/* only 16 data bits in bit maskable reg */
bank_pin_num -= ZYNQ_GPIO_MID_PIN_NUM;
reg_offset = ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num);
} else {
reg_offset = ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num);
}
/*
* get the 32 bit value to be written to the mask/data register where
* the upper 16 bits is the mask and lower 16 bits is the data
*/
state = !!state;
state = ~(1 << (bank_pin_num + ZYNQ_GPIO_MID_PIN_NUM)) &
((state << bank_pin_num) | ZYNQ_GPIO_UPPER_MASK);
writel_relaxed(state, gpio->base_addr + reg_offset);
}
/**
* zynq_gpio_dir_in - Set the direction of the specified GPIO pin as input
* @chip: gpio_chip instance to be worked on
* @pin: gpio pin number within the device
*
* This function uses the read-modify-write sequence to set the direction of
* the gpio pin as input.
*
* Return: 0 always
*/
static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin)
{
u32 reg;
unsigned int bank_num, bank_pin_num;
struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
/* bank 0 pins 7 and 8 are special and cannot be used as inputs */
if (bank_num == 0 && (bank_pin_num == 7 || bank_pin_num == 8))
return -EINVAL;
/* clear the bit in direction mode reg to set the pin as input */
reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
reg &= ~BIT(bank_pin_num);
writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
return 0;
}
/**
* zynq_gpio_dir_out - Set the direction of the specified GPIO pin as output
* @chip: gpio_chip instance to be worked on
* @pin: gpio pin number within the device
* @state: value to be written to specified pin
*
* This function sets the direction of specified GPIO pin as output, configures
* the Output Enable register for the pin and uses zynq_gpio_set to set
* the state of the pin to the value specified.
*
* Return: 0 always
*/
static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
int state)
{
u32 reg;
unsigned int bank_num, bank_pin_num;
struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
/* set the GPIO pin as output */
reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
reg |= BIT(bank_pin_num);
writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
/* configure the output enable reg for the pin */
reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num));
reg |= BIT(bank_pin_num);
writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num));
/* set the state of the pin */
zynq_gpio_set_value(chip, pin, state);
return 0;
}
/**
* zynq_gpio_irq_mask - Disable the interrupts for a gpio pin
* @irq_data: per irq and chip data passed down to chip functions
*
* This function calculates gpio pin number from irq number and sets the
* bit in the Interrupt Disable register of the corresponding bank to disable
* interrupts for that pin.
*/
static void zynq_gpio_irq_mask(struct irq_data *irq_data)
{
unsigned int device_pin_num, bank_num, bank_pin_num;
struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data);
device_pin_num = irq_data->hwirq;
zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
writel_relaxed(BIT(bank_pin_num),
gpio->base_addr + ZYNQ_GPIO_INTDIS_OFFSET(bank_num));
}
/**
* zynq_gpio_irq_unmask - Enable the interrupts for a gpio pin
* @irq_data: irq data containing irq number of gpio pin for the interrupt
* to enable
*
* This function calculates the gpio pin number from irq number and sets the
* bit in the Interrupt Enable register of the corresponding bank to enable
* interrupts for that pin.
*/
static void zynq_gpio_irq_unmask(struct irq_data *irq_data)
{
unsigned int device_pin_num, bank_num, bank_pin_num;
struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data);
device_pin_num = irq_data->hwirq;
zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
writel_relaxed(BIT(bank_pin_num),
gpio->base_addr + ZYNQ_GPIO_INTEN_OFFSET(bank_num));
}
/**
* zynq_gpio_set_irq_type - Set the irq type for a gpio pin
* @irq_data: irq data containing irq number of gpio pin
* @type: interrupt type that is to be set for the gpio pin
*
* This function gets the gpio pin number and its bank from the gpio pin number
* and configures the INT_TYPE, INT_POLARITY and INT_ANY registers.
*
* Return: 0, negative error otherwise.
* TYPE-EDGE_RISING, INT_TYPE - 1, INT_POLARITY - 1, INT_ANY - 0;
* TYPE-EDGE_FALLING, INT_TYPE - 1, INT_POLARITY - 0, INT_ANY - 0;
* TYPE-EDGE_BOTH, INT_TYPE - 1, INT_POLARITY - NA, INT_ANY - 1;
* TYPE-LEVEL_HIGH, INT_TYPE - 0, INT_POLARITY - 1, INT_ANY - NA;
* TYPE-LEVEL_LOW, INT_TYPE - 0, INT_POLARITY - 0, INT_ANY - NA
*/
static int zynq_gpio_set_irq_type(struct irq_data *irq_data, unsigned int type)
{
u32 int_type, int_pol, int_any;
unsigned int device_pin_num, bank_num, bank_pin_num;
struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data);
device_pin_num = irq_data->hwirq;
zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
int_type = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
int_pol = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
int_any = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_INTANY_OFFSET(bank_num));
/*
* based on the type requested, configure the INT_TYPE, INT_POLARITY
* and INT_ANY registers
*/
switch (type) {
case IRQ_TYPE_EDGE_RISING:
int_type |= BIT(bank_pin_num);
int_pol |= BIT(bank_pin_num);
int_any &= ~BIT(bank_pin_num);
break;
case IRQ_TYPE_EDGE_FALLING:
int_type |= BIT(bank_pin_num);
int_pol &= ~BIT(bank_pin_num);
int_any &= ~BIT(bank_pin_num);
break;
case IRQ_TYPE_EDGE_BOTH:
int_type |= BIT(bank_pin_num);
int_any |= BIT(bank_pin_num);
break;
case IRQ_TYPE_LEVEL_HIGH:
int_type &= ~BIT(bank_pin_num);
int_pol |= BIT(bank_pin_num);
break;
case IRQ_TYPE_LEVEL_LOW:
int_type &= ~BIT(bank_pin_num);
int_pol &= ~BIT(bank_pin_num);
break;
default:
return -EINVAL;
}
writel_relaxed(int_type,
gpio->base_addr + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
writel_relaxed(int_pol,
gpio->base_addr + ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
writel_relaxed(int_any,
gpio->base_addr + ZYNQ_GPIO_INTANY_OFFSET(bank_num));
return 0;
}
static int zynq_gpio_set_wake(struct irq_data *data, unsigned int on)
{
if (on)
zynq_gpio_irq_unmask(data);
else
zynq_gpio_irq_mask(data);
return 0;
}
/* irq chip descriptor */
static struct irq_chip zynq_gpio_irqchip = {
.name = DRIVER_NAME,
.irq_mask = zynq_gpio_irq_mask,
.irq_unmask = zynq_gpio_irq_unmask,
.irq_set_type = zynq_gpio_set_irq_type,
.irq_set_wake = zynq_gpio_set_wake,
};
/**
* zynq_gpio_irqhandler - IRQ handler for the gpio banks of a gpio device
* @irq: irq number of the gpio bank where interrupt has occurred
* @desc: irq descriptor instance of the 'irq'
*
* This function reads the Interrupt Status Register of each bank to get the
* gpio pin number which has triggered an interrupt. It then acks the triggered
* interrupt and calls the pin specific handler set by the higher layer
* application for that pin.
* Note: A bug is reported if no handler is set for the gpio pin.
*/
static void zynq_gpio_irqhandler(unsigned int irq, struct irq_desc *desc)
{
u32 int_sts, int_enb;
unsigned int bank_num;
struct zynq_gpio *gpio = irq_get_handler_data(irq);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
chained_irq_enter(irqchip, desc);
for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++) {
int_sts = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_INTSTS_OFFSET(bank_num));
int_enb = readl_relaxed(gpio->base_addr +
ZYNQ_GPIO_INTMASK_OFFSET(bank_num));
int_sts &= ~int_enb;
if (int_sts) {
int offset;
unsigned long pending = int_sts;
for_each_set_bit(offset, &pending, 32) {
unsigned int gpio_irq =
irq_find_mapping(gpio->chip.irqdomain,
offset);
generic_handle_irq(gpio_irq);
}
/* clear IRQ in HW */
writel_relaxed(int_sts, gpio->base_addr +
ZYNQ_GPIO_INTSTS_OFFSET(bank_num));
}
}
chained_irq_exit(irqchip, desc);
}
static int __maybe_unused zynq_gpio_suspend(struct device *dev)
{
if (!device_may_wakeup(dev))
return pm_runtime_force_suspend(dev);
return 0;
}
static int __maybe_unused zynq_gpio_resume(struct device *dev)
{
if (!device_may_wakeup(dev))
return pm_runtime_force_resume(dev);
return 0;
}
static int __maybe_unused zynq_gpio_runtime_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct zynq_gpio *gpio = platform_get_drvdata(pdev);
clk_disable_unprepare(gpio->clk);
return 0;
}
static int __maybe_unused zynq_gpio_runtime_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct zynq_gpio *gpio = platform_get_drvdata(pdev);
return clk_prepare_enable(gpio->clk);
}
static int zynq_gpio_request(struct gpio_chip *chip, unsigned offset)
{
int ret;
ret = pm_runtime_get_sync(chip->dev);
/*
* If the device is already active pm_runtime_get() will return 1 on
* success, but gpio_request still needs to return 0.
*/
return ret < 0 ? ret : 0;
}
static void zynq_gpio_free(struct gpio_chip *chip, unsigned offset)
{
pm_runtime_put(chip->dev);
}
static const struct dev_pm_ops zynq_gpio_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(zynq_gpio_suspend, zynq_gpio_resume)
SET_PM_RUNTIME_PM_OPS(zynq_gpio_runtime_suspend,
zynq_gpio_runtime_resume, NULL)
};
/**
* zynq_gpio_probe - Initialization method for a zynq_gpio device
* @pdev: platform device instance
*
* This function allocates memory resources for the gpio device and registers
* all the banks of the device. It will also set up interrupts for the gpio
* pins.
* Note: Interrupts are disabled for all the banks during initialization.
*
* Return: 0 on success, negative error otherwise.
*/
static int zynq_gpio_probe(struct platform_device *pdev)
{
int ret, bank_num, irq;
struct zynq_gpio *gpio;
struct gpio_chip *chip;
struct resource *res;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
platform_set_drvdata(pdev, gpio);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
gpio->base_addr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(gpio->base_addr))
return PTR_ERR(gpio->base_addr);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "invalid IRQ\n");
return irq;
}
/* configure the gpio chip */
chip = &gpio->chip;
chip->label = "zynq_gpio";
chip->owner = THIS_MODULE;
chip->dev = &pdev->dev;
chip->get = zynq_gpio_get_value;
chip->set = zynq_gpio_set_value;
chip->request = zynq_gpio_request;
chip->free = zynq_gpio_free;
chip->direction_input = zynq_gpio_dir_in;
chip->direction_output = zynq_gpio_dir_out;
chip->base = -1;
chip->ngpio = ZYNQ_GPIO_NR_GPIOS;
/* Enable GPIO clock */
gpio->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(gpio->clk)) {
dev_err(&pdev->dev, "input clock not found.\n");
return PTR_ERR(gpio->clk);
}
ret = clk_prepare_enable(gpio->clk);
if (ret) {
dev_err(&pdev->dev, "Unable to enable clock.\n");
return ret;
}
/* report a bug if gpio chip registration fails */
ret = gpiochip_add(chip);
if (ret) {
dev_err(&pdev->dev, "Failed to add gpio chip\n");
goto err_disable_clk;
}
/* disable interrupts for all banks */
for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++)
writel_relaxed(ZYNQ_GPIO_IXR_DISABLE_ALL, gpio->base_addr +
ZYNQ_GPIO_INTDIS_OFFSET(bank_num));
ret = gpiochip_irqchip_add(chip, &zynq_gpio_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
if (ret) {
dev_err(&pdev->dev, "Failed to add irq chip\n");
goto err_rm_gpiochip;
}
gpiochip_set_chained_irqchip(chip, &zynq_gpio_irqchip, irq,
zynq_gpio_irqhandler);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
device_set_wakeup_capable(&pdev->dev, 1);
return 0;
err_rm_gpiochip:
if (gpiochip_remove(chip))
dev_err(&pdev->dev, "Failed to remove gpio chip\n");
err_disable_clk:
clk_disable_unprepare(gpio->clk);
return ret;
}
/**
* zynq_gpio_remove - Driver removal function
* @pdev: platform device instance
*
* Return: 0 always
*/
static int zynq_gpio_remove(struct platform_device *pdev)
{
int ret;
struct zynq_gpio *gpio = platform_get_drvdata(pdev);
pm_runtime_get_sync(&pdev->dev);
ret = gpiochip_remove(&gpio->chip);
if (ret) {
dev_err(&pdev->dev, "Failed to remove gpio chip\n");
return ret;
}
clk_disable_unprepare(gpio->clk);
device_set_wakeup_capable(&pdev->dev, 0);
return 0;
}
static struct of_device_id zynq_gpio_of_match[] = {
{ .compatible = "xlnx,zynq-gpio-1.0", },
{ /* end of table */ }
};
MODULE_DEVICE_TABLE(of, zynq_gpio_of_match);
static struct platform_driver zynq_gpio_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
.pm = &zynq_gpio_dev_pm_ops,
.of_match_table = zynq_gpio_of_match,
},
.probe = zynq_gpio_probe,
.remove = zynq_gpio_remove,
};
/**
* zynq_gpio_init - Initial driver registration call
*
* Return: value from platform_driver_register
*/
static int __init zynq_gpio_init(void)
{
return platform_driver_register(&zynq_gpio_driver);
}
postcore_initcall(zynq_gpio_init);
MODULE_AUTHOR("Xilinx Inc.");
MODULE_DESCRIPTION("Zynq GPIO driver");
MODULE_LICENSE("GPL");
