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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2014 Linaro Ltd4 *5 * Author: Ulf Hansson <ulf.hansson@linaro.org>6 *7 * MMC power sequence management8 */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 else37 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);118