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 */
devprop_gpiochip_set_names(struct gpio_chip * chip,const struct fwnode_handle * fwnode)29 void 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