LXR linux/drivers/gpio/gpiolib-devprop.c

   1/*
   2 * Device property helpers for GPIO chips.
   3 *
   4 * Copyright (C) 2016, Intel Corporation
   5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/property.h>
  13#include <linux/slab.h>
  14#include <linux/gpio/consumer.h>
  15#include <linux/gpio/driver.h>
  16
  17#include "gpiolib.h"
  18
  19/**
  20 * devprop_gpiochip_set_names - Set GPIO line names using device properties
  21 * @chip: GPIO chip whose lines should be named, if possible
  22 * @fwnode: Property Node containing the gpio-line-names property
  23 *
  24 * Looks for device property "gpio-line-names" and if it exists assigns
  25 * GPIO line names for the chip. The memory allocated for the assigned
  26 * names belong to the underlying firmware node and should not be released
  27 * by the caller.
  28 */
  29void devprop_gpiochip_set_names(struct gpio_chip *chip,
  30                                const struct fwnode_handle *fwnode)
  31{
  32        struct gpio_device *gdev = chip->gpiodev;
  33        const char **names;
  34        int ret, i;
  35
  36        ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
  37                                                NULL, 0);
  38        if (ret < 0)
  39                return;
  40
  41        if (ret != gdev->ngpio) {
  42                dev_warn(&gdev->dev,
  43                         "names %d do not match number of GPIOs %d\n", ret,
  44                         gdev->ngpio);
  45                return;
  46        }
  47
  48        names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
  49        if (!names)
  50                return;
  51
  52        ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
  53                                                names, gdev->ngpio);
  54        if (ret < 0) {
  55                dev_warn(&gdev->dev, "failed to read GPIO line names\n");
  56                kfree(names);
  57                return;
  58        }
  59
  60        for (i = 0; i < gdev->ngpio; i++)
  61                gdev->descs[i].name = names[i];
  62
  63        kfree(names);
  64}
  65