forked from mirrors/linux
5a195c6d4e
Confirm the chip->parent is valid before dereferencing because the parent parameter is optional. Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
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* Device property helpers for GPIO chips.
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*
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* Copyright (C) 2016, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/property.h>
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#include <linux/slab.h>
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#include <linux/gpio/consumer.h>
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#include <linux/gpio/driver.h>
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#include "gpiolib.h"
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/**
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* devprop_gpiochip_set_names - Set GPIO line names using device properties
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* @chip: GPIO chip whose lines should be named, if possible
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*
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* Looks for device property "gpio-line-names" and if it exists assigns
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* GPIO line names for the chip. The memory allocated for the assigned
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* names belong to the underlying firmware node and should not be released
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* by the caller.
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*/
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void devprop_gpiochip_set_names(struct gpio_chip *chip)
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{
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struct gpio_device *gdev = chip->gpiodev;
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const char **names;
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int ret, i;
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if (!chip->parent) {
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dev_warn(&gdev->dev, "GPIO chip parent is NULL\n");
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return;
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}
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ret = device_property_read_string_array(chip->parent, "gpio-line-names",
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NULL, 0);
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if (ret < 0)
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return;
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if (ret != gdev->ngpio) {
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dev_warn(chip->parent,
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"names %d do not match number of GPIOs %d\n", ret,
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gdev->ngpio);
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return;
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}
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names = kcalloc(gdev->ngpio, sizeof(*names), GFP_KERNEL);
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if (!names)
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return;
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ret = device_property_read_string_array(chip->parent, "gpio-line-names",
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names, gdev->ngpio);
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if (ret < 0) {
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dev_warn(chip->parent, "failed to read GPIO line names\n");
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kfree(names);
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return;
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}
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for (i = 0; i < gdev->ngpio; i++)
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gdev->descs[i].name = names[i];
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kfree(names);
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}
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