// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2014 Linaro Ltd * * Author: Ulf Hansson <ulf.hansson@linaro.org> * * MMC power sequence management */ #include <linux/kernel.h> #include <linux/err.h> #include <linux/module.h> #include <linux/of.h> #include <linux/mmc/host.h> #include "pwrseq.h" static DEFINE_MUTEX(pwrseq_list_mutex); static LIST_HEAD(pwrseq_list); int mmc_pwrseq_alloc(struct mmc_host *host) { struct device_node *np; struct mmc_pwrseq *p; np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0); if (!np) return 0; mutex_lock(&pwrseq_list_mutex); list_for_each_entry(p, &pwrseq_list, pwrseq_node) { if (p->dev->of_node == np) { if (!try_module_get(p->owner)) dev_err(host->parent, "increasing module refcount failed\n"); else host->pwrseq = p; break; } } of_node_put(np); mutex_unlock(&pwrseq_list_mutex); if (!host->pwrseq) return -EPROBE_DEFER; dev_info(host->parent, "allocated mmc-pwrseq\n"); return 0; } void mmc_pwrseq_pre_power_on(struct mmc_host *host) { struct mmc_pwrseq *pwrseq = host->pwrseq; if (pwrseq && pwrseq->ops->pre_power_on) pwrseq->ops->pre_power_on(host); } void mmc_pwrseq_post_power_on(struct mmc_host *host) { struct mmc_pwrseq *pwrseq = host->pwrseq; if (pwrseq && pwrseq->ops->post_power_on) pwrseq->ops->post_power_on(host); } void mmc_pwrseq_power_off(struct mmc_host *host) { struct mmc_pwrseq *pwrseq = host->pwrseq; if (pwrseq && pwrseq->ops->power_off) pwrseq->ops->power_off(host); } void mmc_pwrseq_reset(struct mmc_host *host) { struct mmc_pwrseq *pwrseq = host->pwrseq; if (pwrseq && pwrseq->ops->reset) pwrseq->ops->reset(host); } void mmc_pwrseq_free(struct mmc_host *host) { struct mmc_pwrseq *pwrseq = host->pwrseq; if (pwrseq) { module_put(pwrseq->owner); host->pwrseq = NULL; } } int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq) { if (!pwrseq || !pwrseq->ops || !pwrseq->dev) return -EINVAL; mutex_lock(&pwrseq_list_mutex); list_add(&pwrseq->pwrseq_node, &pwrseq_list); mutex_unlock(&pwrseq_list_mutex); return 0; } EXPORT_SYMBOL_GPL(mmc_pwrseq_register); void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq) { if (pwrseq) { mutex_lock(&pwrseq_list_mutex); list_del(&pwrseq->pwrseq_node); mutex_unlock(&pwrseq_list_mutex); } } EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);