Root/drivers/base/pinctrl.c

1/*
2 * Driver core interface to the pinctrl subsystem.
3 *
4 * Copyright (C) 2012 ST-Ericsson SA
5 * Written on behalf of Linaro for ST-Ericsson
6 * Based on bits of regulator core, gpio core and clk core
7 *
8 * Author: Linus Walleij <linus.walleij@linaro.org>
9 *
10 * License terms: GNU General Public License (GPL) version 2
11 */
12
13#include <linux/device.h>
14#include <linux/pinctrl/devinfo.h>
15#include <linux/pinctrl/consumer.h>
16#include <linux/slab.h>
17
18/**
19 * pinctrl_bind_pins() - called by the device core before probe
20 * @dev: the device that is just about to probe
21 */
22int pinctrl_bind_pins(struct device *dev)
23{
24    int ret;
25
26    dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
27    if (!dev->pins)
28        return -ENOMEM;
29
30    dev->pins->p = devm_pinctrl_get(dev);
31    if (IS_ERR(dev->pins->p)) {
32        dev_dbg(dev, "no pinctrl handle\n");
33        ret = PTR_ERR(dev->pins->p);
34        goto cleanup_alloc;
35    }
36
37    dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
38                    PINCTRL_STATE_DEFAULT);
39    if (IS_ERR(dev->pins->default_state)) {
40        dev_dbg(dev, "no default pinctrl state\n");
41        ret = 0;
42        goto cleanup_get;
43    }
44
45    ret = pinctrl_select_state(dev->pins->p, dev->pins->default_state);
46    if (ret) {
47        dev_dbg(dev, "failed to activate default pinctrl state\n");
48        goto cleanup_get;
49    }
50
51    return 0;
52
53    /*
54     * If no pinctrl handle or default state was found for this device,
55     * let's explicitly free the pin container in the device, there is
56     * no point in keeping it around.
57     */
58cleanup_get:
59    devm_pinctrl_put(dev->pins->p);
60cleanup_alloc:
61    devm_kfree(dev, dev->pins);
62    dev->pins = NULL;
63
64    /* Only return deferrals */
65    if (ret != -EPROBE_DEFER)
66        ret = 0;
67
68    return ret;
69}
70

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