GNU Linux-libre 4.4.284-gnu1
[releases.git] / drivers / mmc / core / pwrseq.c
1 /*
2  *  Copyright (C) 2014 Linaro Ltd
3  *
4  * Author: Ulf Hansson <ulf.hansson@linaro.org>
5  *
6  * License terms: GNU General Public License (GPL) version 2
7  *
8  *  MMC power sequence management
9  */
10 #include <linux/kernel.h>
11 #include <linux/platform_device.h>
12 #include <linux/err.h>
13 #include <linux/of.h>
14 #include <linux/of_platform.h>
15
16 #include <linux/mmc/host.h>
17
18 #include "pwrseq.h"
19
20 struct mmc_pwrseq_match {
21         const char *compatible;
22         struct mmc_pwrseq *(*alloc)(struct mmc_host *host, struct device *dev);
23 };
24
25 static struct mmc_pwrseq_match pwrseq_match[] = {
26         {
27                 .compatible = "mmc-pwrseq-simple",
28                 .alloc = mmc_pwrseq_simple_alloc,
29         }, {
30                 .compatible = "mmc-pwrseq-emmc",
31                 .alloc = mmc_pwrseq_emmc_alloc,
32         },
33 };
34
35 static struct mmc_pwrseq_match *mmc_pwrseq_find(struct device_node *np)
36 {
37         struct mmc_pwrseq_match *match = ERR_PTR(-ENODEV);
38         int i;
39
40         for (i = 0; i < ARRAY_SIZE(pwrseq_match); i++) {
41                 if (of_device_is_compatible(np, pwrseq_match[i].compatible)) {
42                         match = &pwrseq_match[i];
43                         break;
44                 }
45         }
46
47         return match;
48 }
49
50 int mmc_pwrseq_alloc(struct mmc_host *host)
51 {
52         struct platform_device *pdev;
53         struct device_node *np;
54         struct mmc_pwrseq_match *match;
55         struct mmc_pwrseq *pwrseq;
56         int ret = 0;
57
58         np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
59         if (!np)
60                 return 0;
61
62         pdev = of_find_device_by_node(np);
63         if (!pdev) {
64                 ret = -ENODEV;
65                 goto err;
66         }
67
68         match = mmc_pwrseq_find(np);
69         if (IS_ERR(match)) {
70                 ret = PTR_ERR(match);
71                 goto err;
72         }
73
74         pwrseq = match->alloc(host, &pdev->dev);
75         if (IS_ERR(pwrseq)) {
76                 ret = PTR_ERR(pwrseq);
77                 goto err;
78         }
79
80         host->pwrseq = pwrseq;
81         dev_info(host->parent, "allocated mmc-pwrseq\n");
82
83 err:
84         of_node_put(np);
85         return ret;
86 }
87
88 void mmc_pwrseq_pre_power_on(struct mmc_host *host)
89 {
90         struct mmc_pwrseq *pwrseq = host->pwrseq;
91
92         if (pwrseq && pwrseq->ops && pwrseq->ops->pre_power_on)
93                 pwrseq->ops->pre_power_on(host);
94 }
95
96 void mmc_pwrseq_post_power_on(struct mmc_host *host)
97 {
98         struct mmc_pwrseq *pwrseq = host->pwrseq;
99
100         if (pwrseq && pwrseq->ops && pwrseq->ops->post_power_on)
101                 pwrseq->ops->post_power_on(host);
102 }
103
104 void mmc_pwrseq_power_off(struct mmc_host *host)
105 {
106         struct mmc_pwrseq *pwrseq = host->pwrseq;
107
108         if (pwrseq && pwrseq->ops && pwrseq->ops->power_off)
109                 pwrseq->ops->power_off(host);
110 }
111
112 void mmc_pwrseq_free(struct mmc_host *host)
113 {
114         struct mmc_pwrseq *pwrseq = host->pwrseq;
115
116         if (pwrseq && pwrseq->ops && pwrseq->ops->free)
117                 pwrseq->ops->free(host);
118
119         host->pwrseq = NULL;
120 }