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117 lines · 2.3 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014 Linaro Ltd
4 *
5 * Author: Ulf Hansson <[email protected]>
6 *
7 * MMC power sequence management
8 */
9#include <linux/kernel.h>
10#include <linux/err.h>
11#include <linux/module.h>
12#include <linux/of.h>
13
14#include <linux/mmc/host.h>
15
16#include "pwrseq.h"
17
18static DEFINE_MUTEX(pwrseq_list_mutex);
19static LIST_HEAD(pwrseq_list);
20
21int mmc_pwrseq_alloc(struct mmc_host *host)
22{
23 struct device_node *np;
24 struct mmc_pwrseq *p;
25
26 np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
27 if (!np)
28 return 0;
29
30 mutex_lock(&pwrseq_list_mutex);
31 list_for_each_entry(p, &pwrseq_list, pwrseq_node) {
32 if (device_match_of_node(p->dev, np)) {
33 if (!try_module_get(p->owner))
34 dev_err(host->parent,
35 "increasing module refcount failed\n");
36 else
37 host->pwrseq = p;
38
39 break;
40 }
41 }
42
43 of_node_put(np);
44 mutex_unlock(&pwrseq_list_mutex);
45
46 if (!host->pwrseq)
47 return -EPROBE_DEFER;
48
49 dev_info(host->parent, "allocated mmc-pwrseq\n");
50
51 return 0;
52}
53
54void mmc_pwrseq_pre_power_on(struct mmc_host *host)
55{
56 struct mmc_pwrseq *pwrseq = host->pwrseq;
57
58 if (pwrseq && pwrseq->ops->pre_power_on)
59 pwrseq->ops->pre_power_on(host);
60}
61
62void mmc_pwrseq_post_power_on(struct mmc_host *host)
63{
64 struct mmc_pwrseq *pwrseq = host->pwrseq;
65
66 if (pwrseq && pwrseq->ops->post_power_on)
67 pwrseq->ops->post_power_on(host);
68}
69
70void mmc_pwrseq_power_off(struct mmc_host *host)
71{
72 struct mmc_pwrseq *pwrseq = host->pwrseq;
73
74 if (pwrseq && pwrseq->ops->power_off)
75 pwrseq->ops->power_off(host);
76}
77
78void mmc_pwrseq_reset(struct mmc_host *host)
79{
80 struct mmc_pwrseq *pwrseq = host->pwrseq;
81
82 if (pwrseq && pwrseq->ops->reset)
83 pwrseq->ops->reset(host);
84}
85
86void mmc_pwrseq_free(struct mmc_host *host)
87{
88 struct mmc_pwrseq *pwrseq = host->pwrseq;
89
90 if (pwrseq) {
91 module_put(pwrseq->owner);
92 host->pwrseq = NULL;
93 }
94}
95
96int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq)
97{
98 if (!pwrseq || !pwrseq->ops || !pwrseq->dev)
99 return -EINVAL;
100
101 mutex_lock(&pwrseq_list_mutex);
102 list_add(&pwrseq->pwrseq_node, &pwrseq_list);
103 mutex_unlock(&pwrseq_list_mutex);
104
105 return 0;
106}
107EXPORT_SYMBOL_GPL(mmc_pwrseq_register);
108
109void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq)
110{
111 if (pwrseq) {
112 mutex_lock(&pwrseq_list_mutex);
113 list_del(&pwrseq->pwrseq_node);
114 mutex_unlock(&pwrseq_list_mutex);
115 }
116}
117EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);