Merge tag '4.4-additional' of git://git.lwn.net/linux
[firefly-linux-kernel-4.4.55.git] / 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  */
22 int 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         dev->pins->init_state = pinctrl_lookup_state(dev->pins->p,
46                                         PINCTRL_STATE_INIT);
47         if (IS_ERR(dev->pins->init_state)) {
48                 /* Not supplying this state is perfectly legal */
49                 dev_dbg(dev, "no init pinctrl state\n");
50
51                 ret = pinctrl_select_state(dev->pins->p,
52                                            dev->pins->default_state);
53         } else {
54                 ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state);
55         }
56
57         if (ret) {
58                 dev_dbg(dev, "failed to activate initial pinctrl state\n");
59                 goto cleanup_get;
60         }
61
62 #ifdef CONFIG_PM
63         /*
64          * If power management is enabled, we also look for the optional
65          * sleep and idle pin states, with semantics as defined in
66          * <linux/pinctrl/pinctrl-state.h>
67          */
68         dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
69                                         PINCTRL_STATE_SLEEP);
70         if (IS_ERR(dev->pins->sleep_state))
71                 /* Not supplying this state is perfectly legal */
72                 dev_dbg(dev, "no sleep pinctrl state\n");
73
74         dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
75                                         PINCTRL_STATE_IDLE);
76         if (IS_ERR(dev->pins->idle_state))
77                 /* Not supplying this state is perfectly legal */
78                 dev_dbg(dev, "no idle pinctrl state\n");
79 #endif
80
81         return 0;
82
83         /*
84          * If no pinctrl handle or default state was found for this device,
85          * let's explicitly free the pin container in the device, there is
86          * no point in keeping it around.
87          */
88 cleanup_get:
89         devm_pinctrl_put(dev->pins->p);
90 cleanup_alloc:
91         devm_kfree(dev, dev->pins);
92         dev->pins = NULL;
93
94         /* Only return deferrals */
95         if (ret != -EPROBE_DEFER)
96                 ret = 0;
97
98         return ret;
99 }