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 *
23 * Looks for device property "gpio-line-names" and if it exists assigns
24 * GPIO line names for the chip. The memory allocated for the assigned
25 * names belong to the underlying firmware node and should not be released
26 * by the caller.
27 */
28void devprop_gpiochip_set_names(struct gpio_chip *chip)
29{
30	struct gpio_device *gdev = chip->gpiodev;
31	const char **names;
32	int ret, i;
33
34	if (!chip->parent) {
35		dev_warn(&gdev->dev, "GPIO chip parent is NULL\n");
36		return;
37	}
38
39	ret = device_property_read_string_array(chip->parent, "gpio-line-names",
40						NULL, 0);
41	if (ret < 0)
42		return;
43
44	if (ret != gdev->ngpio) {
45		dev_warn(chip->parent,
46			 "names %d do not match number of GPIOs %d\n", ret,
47			 gdev->ngpio);
48		return;
49	}
50
51	names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
52	if (!names)
53		return;
54
55	ret = device_property_read_string_array(chip->parent, "gpio-line-names",
56						names, gdev->ngpio);
57	if (ret < 0) {
58		dev_warn(chip->parent, "failed to read GPIO line names\n");
59		kfree(names);
60		return;
61	}
62
63	for (i = 0; i < gdev->ngpio; i++)
64		gdev->descs[i].name = names[i];
65
66	kfree(names);
67}