/*
   * Device property helpers for GPIO chips.
   *
   * Copyright (C) 2016, Intel Corporation
   * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/property.h>
  #include <linux/slab.h>
  #include <linux/gpio/consumer.h>
  #include <linux/gpio/driver.h>
  
  #include "gpiolib.h"
  
  /**
   * devprop_gpiochip_set_names - Set GPIO line names using device properties
   * @chip: GPIO chip whose lines should be named, if possible

   * @fwnode: Property Node containing the gpio-line-names property

   *
   * Looks for device property "gpio-line-names" and if it exists assigns
   * GPIO line names for the chip. The memory allocated for the assigned
   * names belong to the underlying firmware node and should not be released
   * by the caller.
   */

  void devprop_gpiochip_set_names(struct gpio_chip *chip,
  				const struct fwnode_handle *fwnode)

  {
  	struct gpio_device *gdev = chip->gpiodev;
  	const char **names;
  	int ret, i;

  	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",

  						NULL, 0);
  	if (ret < 0)
  		return;
  
  	if (ret != gdev->ngpio) {

  		dev_warn(&gdev->dev,

  			 "names %d do not match number of GPIOs %d
  ", ret,
  			 gdev->ngpio);
  		return;
  	}
  
  	names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
  	if (!names)
  		return;

  	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",

  						names, gdev->ngpio);
  	if (ret < 0) {

  		dev_warn(&gdev->dev, "failed to read GPIO line names
  ");

  		kfree(names);
  		return;
  	}
  
  	for (i = 0; i < gdev->ngpio; i++)
  		gdev->descs[i].name = names[i];
  
  	kfree(names);
  }