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 #include <linux/export.h>
14
15 #include "gpiolib.h"
16
17 /**
18 * devprop_gpiochip_set_names - Set GPIO line names using device properties
19 * @chip: GPIO chip whose lines should be named, if possible
20 * @fwnode: Property Node containing the gpio-line-names property
21 *
22 * Looks for device property "gpio-line-names" and if it exists assigns
23 * GPIO line names for the chip. The memory allocated for the assigned
24 * names belong to the underlying firmware node and should not be released
25 * by the caller.
26 */
devprop_gpiochip_set_names(struct gpio_chip * chip,const struct fwnode_handle * fwnode)27 void devprop_gpiochip_set_names(struct gpio_chip *chip,
28 const struct fwnode_handle *fwnode)
29 {
30 struct gpio_device *gdev = chip->gpiodev;
31 const char **names;
32 int ret, i;
33 int count;
34
35 count = fwnode_property_read_string_array(fwnode, "gpio-line-names",
36 NULL, 0);
37 if (count < 0)
38 return;
39
40 if (count > gdev->ngpio)
41 count = gdev->ngpio;
42
43 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
44 if (!names)
45 return;
46
47 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
48 names, count);
49 if (ret < 0) {
50 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
51 kfree(names);
52 return;
53 }
54
55 for (i = 0; i < count; i++)
56 gdev->descs[i].name = names[i];
57
58 kfree(names);
59 }
60 EXPORT_SYMBOL_GPL(devprop_gpiochip_set_names);
61