tegrakernel/kernel/nvidia/drivers/platform/tegra/rtcpu/reset-group.c

154 lines
3.6 KiB
C

/*
* Copyright (c) 2017 NVIDIA Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "reset-group.h"
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/reset.h>
struct camrtc_reset_group {
struct device *device;
const char *group_name;
int nresets;
struct reset_control *resets[];
};
static void camrtc_reset_group_release(struct device *dev, void *res)
{
const struct camrtc_reset_group *grp = res;
int i;
for (i = 0; i < grp->nresets; i++) {
if (grp->resets[i])
reset_control_put(grp->resets[i]);
}
}
struct camrtc_reset_group *camrtc_reset_group_get(
struct device *dev,
const char *group_name)
{
struct camrtc_reset_group *grp;
struct device_node *np;
const char *group_property;
size_t group_name_len;
int index;
int ret;
if (!dev || !dev->of_node)
return ERR_PTR(-EINVAL);
np = dev->of_node;
group_property = group_name ? group_name : "reset-names";
group_name_len = group_name ? strlen(group_name) : 0;
ret = of_property_count_strings(np, group_property);
if (ret < 0)
return ERR_PTR(-ENOENT);
grp = devres_alloc(camrtc_reset_group_release,
offsetof(struct camrtc_reset_group, resets[ret]) +
group_name_len + 1,
GFP_KERNEL);
if (!grp)
return ERR_PTR(-ENOMEM);
grp->nresets = ret;
grp->device = dev;
grp->group_name = (char *)&grp->resets[grp->nresets];
memcpy((char *)grp->group_name, group_name, group_name_len);
for (index = 0; index < grp->nresets; index++) {
char const *name;
struct reset_control *reset;
ret = of_property_read_string_index(np, group_property,
index, &name);
if (ret < 0)
goto error;
reset = of_reset_control_get(np, name);
if (IS_ERR(reset)) {
ret = PTR_ERR(reset);
goto error;
}
grp->resets[index] = reset;
}
devres_add(dev, grp);
return grp;
error:
devres_free(grp);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(camrtc_reset_group_get);
static void camrtc_reset_group_error(
const struct camrtc_reset_group *grp,
char const *op,
int index,
int error)
{
const char *name = "unnamed";
of_property_read_string_index(grp->device->of_node,
grp->group_name, index, &name);
dev_WARN(grp->device, "%s reset %s (at %s[%d]): %d\n",
op, name, grp->group_name, index, error);
}
void camrtc_reset_group_assert(const struct camrtc_reset_group *grp)
{
int index, index0, err;
if (IS_ERR_OR_NULL(grp))
return;
for (index = 1; index <= grp->nresets; index++) {
index0 = grp->nresets - index;
err = reset_control_assert(grp->resets[index0]);
if (err < 0)
camrtc_reset_group_error(grp, "assert", index0, err);
}
}
EXPORT_SYMBOL_GPL(camrtc_reset_group_assert);
int camrtc_reset_group_deassert(const struct camrtc_reset_group *grp)
{
int index, err;
if (!grp)
return 0;
if (IS_ERR(grp))
return -ENODEV;
for (index = 0; index < grp->nresets; index++) {
err = reset_control_deassert(grp->resets[index]);
if (err < 0) {
camrtc_reset_group_error(grp, "deassert", index, err);
return err;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(camrtc_reset_group_deassert);