drivers/gpio/gpiolib-devprop.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Device property helpers for GPIO chips.
   4  *
   5  * Copyright (C) 2016, Intel Corporation
   6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  */
   8
   9 #include <linux/property.h>
  10 #include <linux/slab.h>
  11 #include <linux/gpio/consumer.h>
  12 #include <linux/gpio/driver.h>
  13
  14 #include "gpiolib.h"
  15
  16 /**
  17  * devprop_gpiochip_set_names - Set GPIO line names using device properties
  18  * @chip: GPIO chip whose lines should be named, if possible
  19  * @fwnode: Property Node containing the gpio-line-names property
  20  *
  21  * Looks for device property "gpio-line-names" and if it exists assigns
  22  * GPIO line names for the chip. The memory allocated for the assigned
  23  * names belong to the underlying firmware node and should not be released
  24  * by the caller.
  25  */
  26 void devprop_gpiochip_set_names(struct gpio_chip *chip,
  27                                 const struct fwnode_handle *fwnode)
  28 {
  29         struct gpio_device *gdev = chip->gpiodev;
  30         const char **names;
  31         int ret, i;
  32         int count;
  33
  34         count = fwnode_property_read_string_array(fwnode, "gpio-line-names",
  35                                                   NULL, 0);
  36         if (count < 0)
  37                 return;
  38
  39         if (count > gdev->ngpio)
  40                 count = gdev->ngpio;
  41
  42         names = kcalloc(count, sizeof(*names), GFP_KERNEL);
  43         if (!names)
  44                 return;
  45
  46         ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
  47                                                 names, count);
  48         if (ret < 0) {
  49                 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
  50                 kfree(names);
  51                 return;
  52         }
  53
  54         for (i = 0; i < count; i++)
  55                 gdev->descs[i].name = names[i];
  56
  57         kfree(names);
  58 }