drivers/gpio/gpio-mockup.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * GPIO Testing Device Driver
  *
  * Copyright (C) 2014  Kamlakant Patel <kamlakant.patel@broadcom.com>
  * Copyright (C) 2015-2016  Bamvor Jian Zhang <bamv2005@gmail.com>
  * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl>
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/gpio/driver.h>
 #include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irq_sim.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/property.h>

 #include "gpiolib.h"

 #define GPIO_MOCKUP_NAME	"gpio-mockup"
 #define GPIO_MOCKUP_MAX_GC	10
 /*
  * We're storing two values per chip: the GPIO base and the number
  * of GPIO lines.
  */
 #define GPIO_MOCKUP_MAX_RANGES	(GPIO_MOCKUP_MAX_GC * 2)
 /* Maximum of three properties + the sentinel. */
 #define GPIO_MOCKUP_MAX_PROP	4

 #define gpio_mockup_err(...)	pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)

 enum {
 	GPIO_MOCKUP_DIR_IN = 0,
 	GPIO_MOCKUP_DIR_OUT = 1,
 };

 /*
  * struct gpio_pin_status - structure describing a GPIO status
  * @dir:       Configures direction of gpio as "in" or "out", 0=in, 1=out
  * @value:     Configures status of the gpio as 0(low) or 1(high)
  */
 struct gpio_mockup_line_status {
 	int dir;
 	int value;
 };

 struct gpio_mockup_chip {
 	struct gpio_chip gc;
 	struct gpio_mockup_line_status *lines;
 	struct irq_sim irqsim;
 	struct dentry *dbg_dir;
 };

 struct gpio_mockup_dbgfs_private {
 	struct gpio_mockup_chip *chip;
 	struct gpio_desc *desc;
 	int offset;
 };

 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
 static int gpio_mockup_num_ranges;
 module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);

 static bool gpio_mockup_named_lines;
 module_param_named(gpio_mockup_named_lines,
 		   gpio_mockup_named_lines, bool, 0400);

 static struct dentry *gpio_mockup_dbg_dir;

 static int gpio_mockup_range_base(unsigned int index)
 {
 	return gpio_mockup_ranges[index * 2];
 }

 static int gpio_mockup_range_ngpio(unsigned int index)
 {
 	return gpio_mockup_ranges[index * 2 + 1];
 }

 static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	return chip->lines[offset].value;
 }

 static void gpio_mockup_set(struct gpio_chip *gc,
 			    unsigned int offset, int value)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	chip->lines[offset].value = !!value;
 }

 static void gpio_mockup_set_multiple(struct gpio_chip *gc,
 				     unsigned long *mask, unsigned long *bits)
 {
 	unsigned int bit;

 	for_each_set_bit(bit, mask, gc->ngpio)
 		gpio_mockup_set(gc, bit, test_bit(bit, bits));

 }

 static int gpio_mockup_dirout(struct gpio_chip *gc,
 			      unsigned int offset, int value)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	gpio_mockup_set(gc, offset, value);
 	chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT;

 	return 0;
 }

 static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN;

 	return 0;
 }

 static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	return !chip->lines[offset].dir;
 }

 static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
 {
 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

 	return irq_sim_irqnum(&chip->irqsim, offset);
 }

 static ssize_t gpio_mockup_event_write(struct file *file,
 				       const char __user *usr_buf,
 				       size_t size, loff_t *ppos)
 {
 	struct gpio_mockup_dbgfs_private *priv;
 	struct gpio_mockup_chip *chip;
 	struct seq_file *sfile;
 	struct gpio_desc *desc;
 	int rv, val;

 	rv = kstrtoint_from_user(usr_buf, size, 0, &val);
 	if (rv)
 		return rv;
 	if (val != 0 && val != 1)
 		return -EINVAL;

 	sfile = file->private_data;
 	priv = sfile->private;
 	desc = priv->desc;
 	chip = priv->chip;

 	gpiod_set_value_cansleep(desc, val);
 	irq_sim_fire(&chip->irqsim, priv->offset);

 	return size;
 }

 static int gpio_mockup_event_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, NULL, inode->i_private);
 }

 static const struct file_operations gpio_mockup_event_ops = {
 	.owner = THIS_MODULE,
 	.open = gpio_mockup_event_open,
 	.write = gpio_mockup_event_write,
 	.llseek = no_llseek,
 };

 static void gpio_mockup_debugfs_setup(struct device *dev,
 				      struct gpio_mockup_chip *chip)
 {
 	struct gpio_mockup_dbgfs_private *priv;
 	struct dentry *evfile, *link;
 	struct gpio_chip *gc;
 	const char *devname;
 	char *name;
 	int i;

 	gc = &chip->gc;
 	devname = dev_name(&gc->gpiodev->dev);

 	chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
 	if (IS_ERR_OR_NULL(chip->dbg_dir))
 		goto err;

 	link = debugfs_create_symlink(gc->label, gpio_mockup_dbg_dir, devname);
 	if (IS_ERR_OR_NULL(link))
 		goto err;

 	for (i = 0; i < gc->ngpio; i++) {
 		name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
 		if (!name)
 			goto err;

 		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 		if (!priv)
 			goto err;

 		priv->chip = chip;
 		priv->offset = i;
 		priv->desc = &gc->gpiodev->descs[i];

 		evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
 					     &gpio_mockup_event_ops);
 		if (IS_ERR_OR_NULL(evfile))
 			goto err;
 	}

 	return;

 err:
 	dev_err(dev, "error creating debugfs event files\n");
 }

 static int gpio_mockup_name_lines(struct device *dev,
 				  struct gpio_mockup_chip *chip)
 {
 	struct gpio_chip *gc = &chip->gc;
 	char **names;
 	int i;

 	names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL);
 	if (!names)
 		return -ENOMEM;

 	for (i = 0; i < gc->ngpio; i++) {
 		names[i] = devm_kasprintf(dev, GFP_KERNEL,
 					  "%s-%d", gc->label, i);
 		if (!names[i])
 			return -ENOMEM;
 	}

 	gc->names = (const char *const *)names;

 	return 0;
 }

 static int gpio_mockup_probe(struct platform_device *pdev)
 {
 	struct gpio_mockup_chip *chip;
 	struct gpio_chip *gc;
 	struct device *dev;
 	const char *name;
 	int rv, base;
 	u16 ngpio;

 	dev = &pdev->dev;

 	rv = device_property_read_u32(dev, "gpio-base", &base);
 	if (rv)
 		base = -1;

 	rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
 	if (rv)
 		return rv;

 	rv = device_property_read_string(dev, "chip-name", &name);
 	if (rv)
 		name = NULL;

 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;

 	if (!name) {
 		name = devm_kasprintf(dev, GFP_KERNEL,
 				      "%s-%c", pdev->name, pdev->id + 'A');
 		if (!name)
 			return -ENOMEM;
 	}

 	gc = &chip->gc;
 	gc->base = base;
 	gc->ngpio = ngpio;
 	gc->label = name;
 	gc->owner = THIS_MODULE;
 	gc->parent = dev;
 	gc->get = gpio_mockup_get;
 	gc->set = gpio_mockup_set;
 	gc->set_multiple = gpio_mockup_set_multiple;
 	gc->direction_output = gpio_mockup_dirout;
 	gc->direction_input = gpio_mockup_dirin;
 	gc->get_direction = gpio_mockup_get_direction;
 	gc->to_irq = gpio_mockup_to_irq;

 	chip->lines = devm_kcalloc(dev, gc->ngpio,
 				   sizeof(*chip->lines), GFP_KERNEL);
 	if (!chip->lines)
 		return -ENOMEM;

 	if (device_property_read_bool(dev, "named-gpio-lines")) {
 		rv = gpio_mockup_name_lines(dev, chip);
 		if (rv)
 			return rv;
 	}

 	rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio);
 	if (rv < 0)
 		return rv;

 	rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
 	if (rv)
 		return rv;

 	if (!IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
 		gpio_mockup_debugfs_setup(dev, chip);

 	return 0;
 }

 static struct platform_driver gpio_mockup_driver = {
 	.driver = {
 		.name = GPIO_MOCKUP_NAME,
 	},
 	.probe = gpio_mockup_probe,
 };

 static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];

 static void gpio_mockup_unregister_pdevs(void)
 {
 	struct platform_device *pdev;
 	int i;

 	for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
 		pdev = gpio_mockup_pdevs[i];

 		if (pdev)
 			platform_device_unregister(pdev);
 	}
 }

 static int __init gpio_mockup_init(void)
 {
 	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
 	int i, prop, num_chips, err = 0, base;
 	struct platform_device_info pdevinfo;
 	struct platform_device *pdev;
 	u16 ngpio;

 	if ((gpio_mockup_num_ranges < 2) ||
 	    (gpio_mockup_num_ranges % 2) ||
 	    (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
 		return -EINVAL;

 	/* Each chip is described by two values. */
 	num_chips = gpio_mockup_num_ranges / 2;

 	/*
 	 * The second value in the <base GPIO - number of GPIOS> pair must
 	 * always be greater than 0.
 	 */
 	for (i = 0; i < num_chips; i++) {
 		if (gpio_mockup_range_ngpio(i) < 0)
 			return -EINVAL;
 	}

 	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
 	if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
 		gpio_mockup_err("error creating debugfs directory\n");

 	err = platform_driver_register(&gpio_mockup_driver);
 	if (err) {
 		gpio_mockup_err("error registering platform driver\n");
 		return err;
 	}

 	for (i = 0; i < num_chips; i++) {
 		memset(properties, 0, sizeof(properties));
 		memset(&pdevinfo, 0, sizeof(pdevinfo));
 		prop = 0;

 		base = gpio_mockup_range_base(i);
 		if (base >= 0)
 			properties[prop++] = PROPERTY_ENTRY_U32("gpio-base",
 								base);

 		ngpio = base < 0 ? gpio_mockup_range_ngpio(i)
 				 : gpio_mockup_range_ngpio(i) - base;
 		properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);

 		if (gpio_mockup_named_lines)
 			properties[prop++] = PROPERTY_ENTRY_BOOL(
 						"named-gpio-lines");

 		pdevinfo.name = GPIO_MOCKUP_NAME;
 		pdevinfo.id = i;
 		pdevinfo.properties = properties;

 		pdev = platform_device_register_full(&pdevinfo);
 		if (IS_ERR(pdev)) {
 			gpio_mockup_err("error registering device");
 			platform_driver_unregister(&gpio_mockup_driver);
 			gpio_mockup_unregister_pdevs();
 			return PTR_ERR(pdev);
 		}

 		gpio_mockup_pdevs[i] = pdev;
 	}

 	return 0;
 }

 static void __exit gpio_mockup_exit(void)
 {
 	debugfs_remove_recursive(gpio_mockup_dbg_dir);
 	platform_driver_unregister(&gpio_mockup_driver);
 	gpio_mockup_unregister_pdevs();
 }

 module_init(gpio_mockup_init);
 module_exit(gpio_mockup_exit);

 MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
 MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
 MODULE_DESCRIPTION("GPIO Testing driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* GPIO Testing Device Driver
	*
	* Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com>
	* Copyright (C) 2015-2016 Bamvor Jian Zhang <bamv2005@gmail.com>
	* Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl>
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/gpio/driver.h>
	#include <linux/gpio/consumer.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/irq_sim.h>
	#include <linux/debugfs.h>
	#include <linux/uaccess.h>
	#include <linux/property.h>

	#include "gpiolib.h"

	#define GPIO_MOCKUP_NAME "gpio-mockup"
	#define GPIO_MOCKUP_MAX_GC 10
	/*
	* We're storing two values per chip: the GPIO base and the number
	* of GPIO lines.
	*/
	#define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2)
	/* Maximum of three properties + the sentinel. */
	#define GPIO_MOCKUP_MAX_PROP 4

	#define gpio_mockup_err(...) pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)

	enum {
	GPIO_MOCKUP_DIR_IN = 0,
	GPIO_MOCKUP_DIR_OUT = 1,
	};

	/*
	* struct gpio_pin_status - structure describing a GPIO status
	* @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out
	* @value: Configures status of the gpio as 0(low) or 1(high)
	*/
	struct gpio_mockup_line_status {
	int dir;
	int value;
	};

	struct gpio_mockup_chip {
	struct gpio_chip gc;
	struct gpio_mockup_line_status *lines;
	struct irq_sim irqsim;
	struct dentry *dbg_dir;
	};

	struct gpio_mockup_dbgfs_private {
	struct gpio_mockup_chip *chip;
	struct gpio_desc *desc;
	int offset;
	};

	static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
	static int gpio_mockup_num_ranges;
	module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);

	static bool gpio_mockup_named_lines;
	module_param_named(gpio_mockup_named_lines,
	gpio_mockup_named_lines, bool, 0400);

	static struct dentry *gpio_mockup_dbg_dir;

	static int gpio_mockup_range_base(unsigned int index)
	{
	return gpio_mockup_ranges[index * 2];
	}

	static int gpio_mockup_range_ngpio(unsigned int index)
	{
	return gpio_mockup_ranges[index * 2 + 1];
	}

	static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	return chip->lines[offset].value;
	}

	static void gpio_mockup_set(struct gpio_chip *gc,
	unsigned int offset, int value)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	chip->lines[offset].value = !!value;
	}

	static void gpio_mockup_set_multiple(struct gpio_chip *gc,
	unsigned long mask, unsigned long bits)
	{
	unsigned int bit;

	for_each_set_bit(bit, mask, gc->ngpio)
	gpio_mockup_set(gc, bit, test_bit(bit, bits));

	}

	static int gpio_mockup_dirout(struct gpio_chip *gc,
	unsigned int offset, int value)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	gpio_mockup_set(gc, offset, value);
	chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT;

	return 0;
	}

	static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN;

	return 0;
	}

	static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	return !chip->lines[offset].dir;
	}

	static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
	{
	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);

	return irq_sim_irqnum(&chip->irqsim, offset);
	}

	static ssize_t gpio_mockup_event_write(struct file *file,
	const char __user *usr_buf,
	size_t size, loff_t *ppos)
	{
	struct gpio_mockup_dbgfs_private *priv;
	struct gpio_mockup_chip *chip;
	struct seq_file *sfile;
	struct gpio_desc *desc;
	int rv, val;

	rv = kstrtoint_from_user(usr_buf, size, 0, &val);
	if (rv)
	return rv;
	if (val != 0 && val != 1)
	return -EINVAL;

	sfile = file->private_data;
	priv = sfile->private;
	desc = priv->desc;
	chip = priv->chip;

	gpiod_set_value_cansleep(desc, val);
	irq_sim_fire(&chip->irqsim, priv->offset);

	return size;
	}

	static int gpio_mockup_event_open(struct inode inode, struct file file)
	{
	return single_open(file, NULL, inode->i_private);
	}

	static const struct file_operations gpio_mockup_event_ops = {
	.owner = THIS_MODULE,
	.open = gpio_mockup_event_open,
	.write = gpio_mockup_event_write,
	.llseek = no_llseek,
	};

	static void gpio_mockup_debugfs_setup(struct device *dev,
	struct gpio_mockup_chip *chip)
	{
	struct gpio_mockup_dbgfs_private *priv;
	struct dentry evfile, link;
	struct gpio_chip *gc;
	const char *devname;
	char *name;
	int i;

	gc = &chip->gc;
	devname = dev_name(&gc->gpiodev->dev);

	chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
	if (IS_ERR_OR_NULL(chip->dbg_dir))
	goto err;

	link = debugfs_create_symlink(gc->label, gpio_mockup_dbg_dir, devname);
	if (IS_ERR_OR_NULL(link))
	goto err;

	for (i = 0; i < gc->ngpio; i++) {
	name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
	if (!name)
	goto err;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	goto err;

	priv->chip = chip;
	priv->offset = i;
	priv->desc = &gc->gpiodev->descs[i];

	evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
	&gpio_mockup_event_ops);
	if (IS_ERR_OR_NULL(evfile))
	goto err;
	}

	return;

	err:
	dev_err(dev, "error creating debugfs event files\n");
	}

	static int gpio_mockup_name_lines(struct device *dev,
	struct gpio_mockup_chip *chip)
	{
	struct gpio_chip *gc = &chip->gc;
	char **names;
	int i;

	names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL);
	if (!names)
	return -ENOMEM;

	for (i = 0; i < gc->ngpio; i++) {
	names[i] = devm_kasprintf(dev, GFP_KERNEL,
	"%s-%d", gc->label, i);
	if (!names[i])
	return -ENOMEM;
	}

	gc->names = (const char const )names;

	return 0;
	}

	static int gpio_mockup_probe(struct platform_device *pdev)
	{
	struct gpio_mockup_chip *chip;
	struct gpio_chip *gc;
	struct device *dev;
	const char *name;
	int rv, base;
	u16 ngpio;

	dev = &pdev->dev;

	rv = device_property_read_u32(dev, "gpio-base", &base);
	if (rv)
	base = -1;

	rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
	if (rv)
	return rv;

	rv = device_property_read_string(dev, "chip-name", &name);
	if (rv)
	name = NULL;

	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
	if (!chip)
	return -ENOMEM;

	if (!name) {
	name = devm_kasprintf(dev, GFP_KERNEL,
	"%s-%c", pdev->name, pdev->id + 'A');
	if (!name)
	return -ENOMEM;
	}

	gc = &chip->gc;
	gc->base = base;
	gc->ngpio = ngpio;
	gc->label = name;
	gc->owner = THIS_MODULE;
	gc->parent = dev;
	gc->get = gpio_mockup_get;
	gc->set = gpio_mockup_set;
	gc->set_multiple = gpio_mockup_set_multiple;
	gc->direction_output = gpio_mockup_dirout;
	gc->direction_input = gpio_mockup_dirin;
	gc->get_direction = gpio_mockup_get_direction;
	gc->to_irq = gpio_mockup_to_irq;

	chip->lines = devm_kcalloc(dev, gc->ngpio,
	sizeof(*chip->lines), GFP_KERNEL);
	if (!chip->lines)
	return -ENOMEM;

	if (device_property_read_bool(dev, "named-gpio-lines")) {
	rv = gpio_mockup_name_lines(dev, chip);
	if (rv)
	return rv;
	}

	rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio);
	if (rv < 0)
	return rv;

	rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
	if (rv)
	return rv;

	if (!IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
	gpio_mockup_debugfs_setup(dev, chip);

	return 0;
	}

	static struct platform_driver gpio_mockup_driver = {
	.driver = {
	.name = GPIO_MOCKUP_NAME,
	},
	.probe = gpio_mockup_probe,
	};

	static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];

	static void gpio_mockup_unregister_pdevs(void)
	{
	struct platform_device *pdev;
	int i;

	for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
	pdev = gpio_mockup_pdevs[i];

	if (pdev)
	platform_device_unregister(pdev);
	}
	}

	static int __init gpio_mockup_init(void)
	{
	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
	int i, prop, num_chips, err = 0, base;
	struct platform_device_info pdevinfo;
	struct platform_device *pdev;
	u16 ngpio;

	if ((gpio_mockup_num_ranges < 2) \|\|
	(gpio_mockup_num_ranges % 2) \|\|
	(gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
	return -EINVAL;

	/* Each chip is described by two values. */
	num_chips = gpio_mockup_num_ranges / 2;

	/*
	* The second value in the <base GPIO - number of GPIOS> pair must
	* always be greater than 0.
	*/
	for (i = 0; i < num_chips; i++) {
	if (gpio_mockup_range_ngpio(i) < 0)
	return -EINVAL;
	}

	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
	if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
	gpio_mockup_err("error creating debugfs directory\n");

	err = platform_driver_register(&gpio_mockup_driver);
	if (err) {
	gpio_mockup_err("error registering platform driver\n");
	return err;
	}

	for (i = 0; i < num_chips; i++) {
	memset(properties, 0, sizeof(properties));
	memset(&pdevinfo, 0, sizeof(pdevinfo));
	prop = 0;

	base = gpio_mockup_range_base(i);
	if (base >= 0)
	properties[prop++] = PROPERTY_ENTRY_U32("gpio-base",
	base);

	ngpio = base < 0 ? gpio_mockup_range_ngpio(i)
	: gpio_mockup_range_ngpio(i) - base;
	properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);

	if (gpio_mockup_named_lines)
	properties[prop++] = PROPERTY_ENTRY_BOOL(
	"named-gpio-lines");

	pdevinfo.name = GPIO_MOCKUP_NAME;
	pdevinfo.id = i;
	pdevinfo.properties = properties;

	pdev = platform_device_register_full(&pdevinfo);
	if (IS_ERR(pdev)) {
	gpio_mockup_err("error registering device");
	platform_driver_unregister(&gpio_mockup_driver);
	gpio_mockup_unregister_pdevs();
	return PTR_ERR(pdev);
	}

	gpio_mockup_pdevs[i] = pdev;
	}

	return 0;
	}

	static void __exit gpio_mockup_exit(void)
	{
	debugfs_remove_recursive(gpio_mockup_dbg_dir);
	platform_driver_unregister(&gpio_mockup_driver);
	gpio_mockup_unregister_pdevs();
	}

	module_init(gpio_mockup_init);
	module_exit(gpio_mockup_exit);

	MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
	MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
	MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
	MODULE_DESCRIPTION("GPIO Testing driver");
	MODULE_LICENSE("GPL v2");