linux/drivers/mmc/core/pwrseq.c
Srinivas Kandagatla d97a1e5d7c mmc: pwrseq: convert to proper platform device
simple-pwrseq and emmc-pwrseq drivers rely on platform_device
structure from of_find_device_by_node(), this works mostly. But, as there
is no driver associated with this devices, cases like default/init pinctrl
setup would never be performed by pwrseq. This becomes problem when the
gpios used in pwrseq require pinctrl setup.

Currently most of the common pinctrl setup is done in
drivers/base/pinctrl.c by pinctrl_bind_pins().

There are two ways to solve this issue on either convert pwrseq drivers
to a proper platform drivers or copy the exact code from
pcintrl_bind_pins(). I prefer converting pwrseq to proper drivers so that
other cases like setting up clks/parents from dt would also be possible.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-02 10:33:30 +02:00

111 lines
2.2 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_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);