linux/drivers/mmc/core/pwrseq.c

119 lines
2.3 KiB
C

/*
* Copyright (C) 2014 Linaro Ltd
*
* Author: Ulf Hansson <ulf.hansson@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*
* 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);