linux/drivers/mmc/core/pwrseq.c
Javier Martinez Canillas 636efbc664 mmc: pwrseq: Fix error code propagation in mmc_pwrseq_simple_alloc()
If the struct mmc_pwrseq_match .alloc function used to allocate a
struct mmc_pwrseq fails, the error is propagated to mmc_of_parse().

But instead of returning the error code in pwrseq, host->pwrseq is
returned which will always be 0. So mmc_of_parse() succeeds even if
the pwrseq .alloc function failed and host->pwrseq is NULL.

This makes the SDIO device to not be powered if the power sequencing
.alloc functions wants to be deferred due a missing resource because
the mmc controller driver probe did wrongly succeed.

Fixes: 0f12a0ce4c ("mmc: pwrseq: simplify alloc/free hooks")
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-04-17 10:17:19 +02:00

121 lines
2.4 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/platform_device.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/mmc/host.h>
#include "pwrseq.h"
struct mmc_pwrseq_match {
const char *compatible;
struct mmc_pwrseq *(*alloc)(struct mmc_host *host, struct device *dev);
};
static struct mmc_pwrseq_match pwrseq_match[] = {
{
.compatible = "mmc-pwrseq-simple",
.alloc = mmc_pwrseq_simple_alloc,
}, {
.compatible = "mmc-pwrseq-emmc",
.alloc = mmc_pwrseq_emmc_alloc,
},
};
static struct mmc_pwrseq_match *mmc_pwrseq_find(struct device_node *np)
{
struct mmc_pwrseq_match *match = ERR_PTR(-ENODEV);
int i;
for (i = 0; i < ARRAY_SIZE(pwrseq_match); i++) {
if (of_device_is_compatible(np, pwrseq_match[i].compatible)) {
match = &pwrseq_match[i];
break;
}
}
return match;
}
int mmc_pwrseq_alloc(struct mmc_host *host)
{
struct platform_device *pdev;
struct device_node *np;
struct mmc_pwrseq_match *match;
struct mmc_pwrseq *pwrseq;
int ret = 0;
np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
if (!np)
return 0;
pdev = of_find_device_by_node(np);
if (!pdev) {
ret = -ENODEV;
goto err;
}
match = mmc_pwrseq_find(np);
if (IS_ERR(match)) {
ret = PTR_ERR(match);
goto err;
}
pwrseq = match->alloc(host, &pdev->dev);
if (IS_ERR(pwrseq)) {
ret = PTR_ERR(pwrseq);
goto err;
}
host->pwrseq = pwrseq;
dev_info(host->parent, "allocated mmc-pwrseq\n");
err:
of_node_put(np);
return ret;
}
void mmc_pwrseq_pre_power_on(struct mmc_host *host)
{
struct mmc_pwrseq *pwrseq = host->pwrseq;
if (pwrseq && pwrseq->ops && 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 && 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 && 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 && pwrseq->ops && pwrseq->ops->free)
pwrseq->ops->free(host);
host->pwrseq = NULL;
}