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 }