mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Philipp Zabel](/assets/img/avatar_default.png)
Abort instead of returning a new reset control for a reset controller
device that is going to have its module unloaded.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 61fc413176
("reset: Add reset controller API")
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210607082615.15160-1-p.zabel@pengutronix.de
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
1276 lines
31 KiB
C
1276 lines
31 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Reset Controller framework
|
|
*
|
|
* Copyright 2013 Philipp Zabel, Pengutronix
|
|
*/
|
|
#include <linux/atomic.h>
|
|
#include <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/reset.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/slab.h>
|
|
|
|
static DEFINE_MUTEX(reset_list_mutex);
|
|
static LIST_HEAD(reset_controller_list);
|
|
|
|
static DEFINE_MUTEX(reset_lookup_mutex);
|
|
static LIST_HEAD(reset_lookup_list);
|
|
|
|
/**
|
|
* struct reset_control - a reset control
|
|
* @rcdev: a pointer to the reset controller device
|
|
* this reset control belongs to
|
|
* @list: list entry for the rcdev's reset controller list
|
|
* @id: ID of the reset controller in the reset
|
|
* controller device
|
|
* @refcnt: Number of gets of this reset_control
|
|
* @acquired: Only one reset_control may be acquired for a given rcdev and id.
|
|
* @shared: Is this a shared (1), or an exclusive (0) reset_control?
|
|
* @array: Is this an array of reset controls (1)?
|
|
* @deassert_count: Number of times this reset line has been deasserted
|
|
* @triggered_count: Number of times this reset line has been reset. Currently
|
|
* only used for shared resets, which means that the value
|
|
* will be either 0 or 1.
|
|
*/
|
|
struct reset_control {
|
|
struct reset_controller_dev *rcdev;
|
|
struct list_head list;
|
|
unsigned int id;
|
|
struct kref refcnt;
|
|
bool acquired;
|
|
bool shared;
|
|
bool array;
|
|
atomic_t deassert_count;
|
|
atomic_t triggered_count;
|
|
};
|
|
|
|
/**
|
|
* struct reset_control_array - an array of reset controls
|
|
* @base: reset control for compatibility with reset control API functions
|
|
* @num_rstcs: number of reset controls
|
|
* @rstc: array of reset controls
|
|
*/
|
|
struct reset_control_array {
|
|
struct reset_control base;
|
|
unsigned int num_rstcs;
|
|
struct reset_control *rstc[];
|
|
};
|
|
|
|
static const char *rcdev_name(struct reset_controller_dev *rcdev)
|
|
{
|
|
if (rcdev->dev)
|
|
return dev_name(rcdev->dev);
|
|
|
|
if (rcdev->of_node)
|
|
return rcdev->of_node->full_name;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* of_reset_simple_xlate - translate reset_spec to the reset line number
|
|
* @rcdev: a pointer to the reset controller device
|
|
* @reset_spec: reset line specifier as found in the device tree
|
|
*
|
|
* This static translation function is used by default if of_xlate in
|
|
* :c:type:`reset_controller_dev` is not set. It is useful for all reset
|
|
* controllers with 1:1 mapping, where reset lines can be indexed by number
|
|
* without gaps.
|
|
*/
|
|
static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
|
|
const struct of_phandle_args *reset_spec)
|
|
{
|
|
if (reset_spec->args[0] >= rcdev->nr_resets)
|
|
return -EINVAL;
|
|
|
|
return reset_spec->args[0];
|
|
}
|
|
|
|
/**
|
|
* reset_controller_register - register a reset controller device
|
|
* @rcdev: a pointer to the initialized reset controller device
|
|
*/
|
|
int reset_controller_register(struct reset_controller_dev *rcdev)
|
|
{
|
|
if (!rcdev->of_xlate) {
|
|
rcdev->of_reset_n_cells = 1;
|
|
rcdev->of_xlate = of_reset_simple_xlate;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&rcdev->reset_control_head);
|
|
|
|
mutex_lock(&reset_list_mutex);
|
|
list_add(&rcdev->list, &reset_controller_list);
|
|
mutex_unlock(&reset_list_mutex);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_controller_register);
|
|
|
|
/**
|
|
* reset_controller_unregister - unregister a reset controller device
|
|
* @rcdev: a pointer to the reset controller device
|
|
*/
|
|
void reset_controller_unregister(struct reset_controller_dev *rcdev)
|
|
{
|
|
mutex_lock(&reset_list_mutex);
|
|
list_del(&rcdev->list);
|
|
mutex_unlock(&reset_list_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_controller_unregister);
|
|
|
|
static void devm_reset_controller_release(struct device *dev, void *res)
|
|
{
|
|
reset_controller_unregister(*(struct reset_controller_dev **)res);
|
|
}
|
|
|
|
/**
|
|
* devm_reset_controller_register - resource managed reset_controller_register()
|
|
* @dev: device that is registering this reset controller
|
|
* @rcdev: a pointer to the initialized reset controller device
|
|
*
|
|
* Managed reset_controller_register(). For reset controllers registered by
|
|
* this function, reset_controller_unregister() is automatically called on
|
|
* driver detach. See reset_controller_register() for more information.
|
|
*/
|
|
int devm_reset_controller_register(struct device *dev,
|
|
struct reset_controller_dev *rcdev)
|
|
{
|
|
struct reset_controller_dev **rcdevp;
|
|
int ret;
|
|
|
|
rcdevp = devres_alloc(devm_reset_controller_release, sizeof(*rcdevp),
|
|
GFP_KERNEL);
|
|
if (!rcdevp)
|
|
return -ENOMEM;
|
|
|
|
ret = reset_controller_register(rcdev);
|
|
if (ret) {
|
|
devres_free(rcdevp);
|
|
return ret;
|
|
}
|
|
|
|
*rcdevp = rcdev;
|
|
devres_add(dev, rcdevp);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_reset_controller_register);
|
|
|
|
/**
|
|
* reset_controller_add_lookup - register a set of lookup entries
|
|
* @lookup: array of reset lookup entries
|
|
* @num_entries: number of entries in the lookup array
|
|
*/
|
|
void reset_controller_add_lookup(struct reset_control_lookup *lookup,
|
|
unsigned int num_entries)
|
|
{
|
|
struct reset_control_lookup *entry;
|
|
unsigned int i;
|
|
|
|
mutex_lock(&reset_lookup_mutex);
|
|
for (i = 0; i < num_entries; i++) {
|
|
entry = &lookup[i];
|
|
|
|
if (!entry->dev_id || !entry->provider) {
|
|
pr_warn("%s(): reset lookup entry badly specified, skipping\n",
|
|
__func__);
|
|
continue;
|
|
}
|
|
|
|
list_add_tail(&entry->list, &reset_lookup_list);
|
|
}
|
|
mutex_unlock(&reset_lookup_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_controller_add_lookup);
|
|
|
|
static inline struct reset_control_array *
|
|
rstc_to_array(struct reset_control *rstc) {
|
|
return container_of(rstc, struct reset_control_array, base);
|
|
}
|
|
|
|
static int reset_control_array_reset(struct reset_control_array *resets)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
ret = reset_control_reset(resets->rstc[i]);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int reset_control_array_rearm(struct reset_control_array *resets)
|
|
{
|
|
struct reset_control *rstc;
|
|
int i;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
rstc = resets->rstc[i];
|
|
|
|
if (!rstc)
|
|
continue;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (rstc->shared) {
|
|
if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
|
|
return -EINVAL;
|
|
} else {
|
|
if (!rstc->acquired)
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
rstc = resets->rstc[i];
|
|
|
|
if (rstc && rstc->shared)
|
|
WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int reset_control_array_assert(struct reset_control_array *resets)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
ret = reset_control_assert(resets->rstc[i]);
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
while (i--)
|
|
reset_control_deassert(resets->rstc[i]);
|
|
return ret;
|
|
}
|
|
|
|
static int reset_control_array_deassert(struct reset_control_array *resets)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
ret = reset_control_deassert(resets->rstc[i]);
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
while (i--)
|
|
reset_control_assert(resets->rstc[i]);
|
|
return ret;
|
|
}
|
|
|
|
static int reset_control_array_acquire(struct reset_control_array *resets)
|
|
{
|
|
unsigned int i;
|
|
int err;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++) {
|
|
err = reset_control_acquire(resets->rstc[i]);
|
|
if (err < 0)
|
|
goto release;
|
|
}
|
|
|
|
return 0;
|
|
|
|
release:
|
|
while (i--)
|
|
reset_control_release(resets->rstc[i]);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void reset_control_array_release(struct reset_control_array *resets)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < resets->num_rstcs; i++)
|
|
reset_control_release(resets->rstc[i]);
|
|
}
|
|
|
|
static inline bool reset_control_is_array(struct reset_control *rstc)
|
|
{
|
|
return rstc->array;
|
|
}
|
|
|
|
/**
|
|
* reset_control_reset - reset the controlled device
|
|
* @rstc: reset controller
|
|
*
|
|
* On a shared reset line the actual reset pulse is only triggered once for the
|
|
* lifetime of the reset_control instance: for all but the first caller this is
|
|
* a no-op.
|
|
* Consumers must not use reset_control_(de)assert on shared reset lines when
|
|
* reset_control_reset has been used.
|
|
*
|
|
* If rstc is NULL it is an optional reset and the function will just
|
|
* return 0.
|
|
*/
|
|
int reset_control_reset(struct reset_control *rstc)
|
|
{
|
|
int ret;
|
|
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
return reset_control_array_reset(rstc_to_array(rstc));
|
|
|
|
if (!rstc->rcdev->ops->reset)
|
|
return -ENOTSUPP;
|
|
|
|
if (rstc->shared) {
|
|
if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
|
|
return -EINVAL;
|
|
|
|
if (atomic_inc_return(&rstc->triggered_count) != 1)
|
|
return 0;
|
|
} else {
|
|
if (!rstc->acquired)
|
|
return -EPERM;
|
|
}
|
|
|
|
ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
|
|
if (rstc->shared && ret)
|
|
atomic_dec(&rstc->triggered_count);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_reset);
|
|
|
|
/**
|
|
* reset_control_bulk_reset - reset the controlled devices in order
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*
|
|
* Issue a reset on all provided reset controls, in order.
|
|
*
|
|
* See also: reset_control_reset()
|
|
*/
|
|
int reset_control_bulk_reset(int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < num_rstcs; i++) {
|
|
ret = reset_control_reset(rstcs[i].rstc);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_reset);
|
|
|
|
/**
|
|
* reset_control_rearm - allow shared reset line to be re-triggered"
|
|
* @rstc: reset controller
|
|
*
|
|
* On a shared reset line the actual reset pulse is only triggered once for the
|
|
* lifetime of the reset_control instance, except if this call is used.
|
|
*
|
|
* Calls to this function must be balanced with calls to reset_control_reset,
|
|
* a warning is thrown in case triggered_count ever dips below 0.
|
|
*
|
|
* Consumers must not use reset_control_(de)assert on shared reset lines when
|
|
* reset_control_reset or reset_control_rearm have been used.
|
|
*
|
|
* If rstc is NULL the function will just return 0.
|
|
*/
|
|
int reset_control_rearm(struct reset_control *rstc)
|
|
{
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
return reset_control_array_rearm(rstc_to_array(rstc));
|
|
|
|
if (rstc->shared) {
|
|
if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
|
|
return -EINVAL;
|
|
|
|
WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
|
|
} else {
|
|
if (!rstc->acquired)
|
|
return -EPERM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_rearm);
|
|
|
|
/**
|
|
* reset_control_assert - asserts the reset line
|
|
* @rstc: reset controller
|
|
*
|
|
* Calling this on an exclusive reset controller guarantees that the reset
|
|
* will be asserted. When called on a shared reset controller the line may
|
|
* still be deasserted, as long as other users keep it so.
|
|
*
|
|
* For shared reset controls a driver cannot expect the hw's registers and
|
|
* internal state to be reset, but must be prepared for this to happen.
|
|
* Consumers must not use reset_control_reset on shared reset lines when
|
|
* reset_control_(de)assert has been used.
|
|
*
|
|
* If rstc is NULL it is an optional reset and the function will just
|
|
* return 0.
|
|
*/
|
|
int reset_control_assert(struct reset_control *rstc)
|
|
{
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
return reset_control_array_assert(rstc_to_array(rstc));
|
|
|
|
if (rstc->shared) {
|
|
if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
|
|
return -EINVAL;
|
|
|
|
if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))
|
|
return -EINVAL;
|
|
|
|
if (atomic_dec_return(&rstc->deassert_count) != 0)
|
|
return 0;
|
|
|
|
/*
|
|
* Shared reset controls allow the reset line to be in any state
|
|
* after this call, so doing nothing is a valid option.
|
|
*/
|
|
if (!rstc->rcdev->ops->assert)
|
|
return 0;
|
|
} else {
|
|
/*
|
|
* If the reset controller does not implement .assert(), there
|
|
* is no way to guarantee that the reset line is asserted after
|
|
* this call.
|
|
*/
|
|
if (!rstc->rcdev->ops->assert)
|
|
return -ENOTSUPP;
|
|
|
|
if (!rstc->acquired) {
|
|
WARN(1, "reset %s (ID: %u) is not acquired\n",
|
|
rcdev_name(rstc->rcdev), rstc->id);
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_assert);
|
|
|
|
/**
|
|
* reset_control_bulk_assert - asserts the reset lines in order
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*
|
|
* Assert the reset lines for all provided reset controls, in order.
|
|
* If an assertion fails, already asserted resets are deasserted again.
|
|
*
|
|
* See also: reset_control_assert()
|
|
*/
|
|
int reset_control_bulk_assert(int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < num_rstcs; i++) {
|
|
ret = reset_control_assert(rstcs[i].rstc);
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
while (i--)
|
|
reset_control_deassert(rstcs[i].rstc);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_assert);
|
|
|
|
/**
|
|
* reset_control_deassert - deasserts the reset line
|
|
* @rstc: reset controller
|
|
*
|
|
* After calling this function, the reset is guaranteed to be deasserted.
|
|
* Consumers must not use reset_control_reset on shared reset lines when
|
|
* reset_control_(de)assert has been used.
|
|
*
|
|
* If rstc is NULL it is an optional reset and the function will just
|
|
* return 0.
|
|
*/
|
|
int reset_control_deassert(struct reset_control *rstc)
|
|
{
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
return reset_control_array_deassert(rstc_to_array(rstc));
|
|
|
|
if (rstc->shared) {
|
|
if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
|
|
return -EINVAL;
|
|
|
|
if (atomic_inc_return(&rstc->deassert_count) != 1)
|
|
return 0;
|
|
} else {
|
|
if (!rstc->acquired) {
|
|
WARN(1, "reset %s (ID: %u) is not acquired\n",
|
|
rcdev_name(rstc->rcdev), rstc->id);
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the reset controller does not implement .deassert(), we assume
|
|
* that it handles self-deasserting reset lines via .reset(). In that
|
|
* case, the reset lines are deasserted by default. If that is not the
|
|
* case, the reset controller driver should implement .deassert() and
|
|
* return -ENOTSUPP.
|
|
*/
|
|
if (!rstc->rcdev->ops->deassert)
|
|
return 0;
|
|
|
|
return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_deassert);
|
|
|
|
/**
|
|
* reset_control_bulk_deassert - deasserts the reset lines in reverse order
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*
|
|
* Deassert the reset lines for all provided reset controls, in reverse order.
|
|
* If a deassertion fails, already deasserted resets are asserted again.
|
|
*
|
|
* See also: reset_control_deassert()
|
|
*/
|
|
int reset_control_bulk_deassert(int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = num_rstcs - 1; i >= 0; i--) {
|
|
ret = reset_control_deassert(rstcs[i].rstc);
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
while (i < num_rstcs)
|
|
reset_control_assert(rstcs[i++].rstc);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_deassert);
|
|
|
|
/**
|
|
* reset_control_status - returns a negative errno if not supported, a
|
|
* positive value if the reset line is asserted, or zero if the reset
|
|
* line is not asserted or if the desc is NULL (optional reset).
|
|
* @rstc: reset controller
|
|
*/
|
|
int reset_control_status(struct reset_control *rstc)
|
|
{
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc))
|
|
return -EINVAL;
|
|
|
|
if (rstc->rcdev->ops->status)
|
|
return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
|
|
|
|
return -ENOTSUPP;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_status);
|
|
|
|
/**
|
|
* reset_control_acquire() - acquires a reset control for exclusive use
|
|
* @rstc: reset control
|
|
*
|
|
* This is used to explicitly acquire a reset control for exclusive use. Note
|
|
* that exclusive resets are requested as acquired by default. In order for a
|
|
* second consumer to be able to control the reset, the first consumer has to
|
|
* release it first. Typically the easiest way to achieve this is to call the
|
|
* reset_control_get_exclusive_released() to obtain an instance of the reset
|
|
* control. Such reset controls are not acquired by default.
|
|
*
|
|
* Consumers implementing shared access to an exclusive reset need to follow
|
|
* a specific protocol in order to work together. Before consumers can change
|
|
* a reset they must acquire exclusive access using reset_control_acquire().
|
|
* After they are done operating the reset, they must release exclusive access
|
|
* with a call to reset_control_release(). Consumers are not granted exclusive
|
|
* access to the reset as long as another consumer hasn't released a reset.
|
|
*
|
|
* See also: reset_control_release()
|
|
*/
|
|
int reset_control_acquire(struct reset_control *rstc)
|
|
{
|
|
struct reset_control *rc;
|
|
|
|
if (!rstc)
|
|
return 0;
|
|
|
|
if (WARN_ON(IS_ERR(rstc)))
|
|
return -EINVAL;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
return reset_control_array_acquire(rstc_to_array(rstc));
|
|
|
|
mutex_lock(&reset_list_mutex);
|
|
|
|
if (rstc->acquired) {
|
|
mutex_unlock(&reset_list_mutex);
|
|
return 0;
|
|
}
|
|
|
|
list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {
|
|
if (rstc != rc && rstc->id == rc->id) {
|
|
if (rc->acquired) {
|
|
mutex_unlock(&reset_list_mutex);
|
|
return -EBUSY;
|
|
}
|
|
}
|
|
}
|
|
|
|
rstc->acquired = true;
|
|
|
|
mutex_unlock(&reset_list_mutex);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_acquire);
|
|
|
|
/**
|
|
* reset_control_bulk_acquire - acquires reset controls for exclusive use
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*
|
|
* This is used to explicitly acquire reset controls requested with
|
|
* reset_control_bulk_get_exclusive_release() for temporary exclusive use.
|
|
*
|
|
* See also: reset_control_acquire(), reset_control_bulk_release()
|
|
*/
|
|
int reset_control_bulk_acquire(int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < num_rstcs; i++) {
|
|
ret = reset_control_acquire(rstcs[i].rstc);
|
|
if (ret)
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
while (i--)
|
|
reset_control_release(rstcs[i].rstc);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_acquire);
|
|
|
|
/**
|
|
* reset_control_release() - releases exclusive access to a reset control
|
|
* @rstc: reset control
|
|
*
|
|
* Releases exclusive access right to a reset control previously obtained by a
|
|
* call to reset_control_acquire(). Until a consumer calls this function, no
|
|
* other consumers will be granted exclusive access.
|
|
*
|
|
* See also: reset_control_acquire()
|
|
*/
|
|
void reset_control_release(struct reset_control *rstc)
|
|
{
|
|
if (!rstc || WARN_ON(IS_ERR(rstc)))
|
|
return;
|
|
|
|
if (reset_control_is_array(rstc))
|
|
reset_control_array_release(rstc_to_array(rstc));
|
|
else
|
|
rstc->acquired = false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_release);
|
|
|
|
/**
|
|
* reset_control_bulk_release() - releases exclusive access to reset controls
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*
|
|
* Releases exclusive access right to reset controls previously obtained by a
|
|
* call to reset_control_bulk_acquire().
|
|
*
|
|
* See also: reset_control_release(), reset_control_bulk_acquire()
|
|
*/
|
|
void reset_control_bulk_release(int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_rstcs; i++)
|
|
reset_control_release(rstcs[i].rstc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_release);
|
|
|
|
static struct reset_control *
|
|
__reset_control_get_internal(struct reset_controller_dev *rcdev,
|
|
unsigned int index, bool shared, bool acquired)
|
|
{
|
|
struct reset_control *rstc;
|
|
|
|
lockdep_assert_held(&reset_list_mutex);
|
|
|
|
list_for_each_entry(rstc, &rcdev->reset_control_head, list) {
|
|
if (rstc->id == index) {
|
|
/*
|
|
* Allow creating a secondary exclusive reset_control
|
|
* that is initially not acquired for an already
|
|
* controlled reset line.
|
|
*/
|
|
if (!rstc->shared && !shared && !acquired)
|
|
break;
|
|
|
|
if (WARN_ON(!rstc->shared || !shared))
|
|
return ERR_PTR(-EBUSY);
|
|
|
|
kref_get(&rstc->refcnt);
|
|
return rstc;
|
|
}
|
|
}
|
|
|
|
rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
|
|
if (!rstc)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (!try_module_get(rcdev->owner)) {
|
|
kfree(rstc);
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
rstc->rcdev = rcdev;
|
|
list_add(&rstc->list, &rcdev->reset_control_head);
|
|
rstc->id = index;
|
|
kref_init(&rstc->refcnt);
|
|
rstc->acquired = acquired;
|
|
rstc->shared = shared;
|
|
|
|
return rstc;
|
|
}
|
|
|
|
static void __reset_control_release(struct kref *kref)
|
|
{
|
|
struct reset_control *rstc = container_of(kref, struct reset_control,
|
|
refcnt);
|
|
|
|
lockdep_assert_held(&reset_list_mutex);
|
|
|
|
module_put(rstc->rcdev->owner);
|
|
|
|
list_del(&rstc->list);
|
|
kfree(rstc);
|
|
}
|
|
|
|
static void __reset_control_put_internal(struct reset_control *rstc)
|
|
{
|
|
lockdep_assert_held(&reset_list_mutex);
|
|
|
|
kref_put(&rstc->refcnt, __reset_control_release);
|
|
}
|
|
|
|
struct reset_control *
|
|
__of_reset_control_get(struct device_node *node, const char *id, int index,
|
|
bool shared, bool optional, bool acquired)
|
|
{
|
|
struct reset_control *rstc;
|
|
struct reset_controller_dev *r, *rcdev;
|
|
struct of_phandle_args args;
|
|
int rstc_id;
|
|
int ret;
|
|
|
|
if (!node)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (id) {
|
|
index = of_property_match_string(node,
|
|
"reset-names", id);
|
|
if (index == -EILSEQ)
|
|
return ERR_PTR(index);
|
|
if (index < 0)
|
|
return optional ? NULL : ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
|
|
index, &args);
|
|
if (ret == -EINVAL)
|
|
return ERR_PTR(ret);
|
|
if (ret)
|
|
return optional ? NULL : ERR_PTR(ret);
|
|
|
|
mutex_lock(&reset_list_mutex);
|
|
rcdev = NULL;
|
|
list_for_each_entry(r, &reset_controller_list, list) {
|
|
if (args.np == r->of_node) {
|
|
rcdev = r;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!rcdev) {
|
|
rstc = ERR_PTR(-EPROBE_DEFER);
|
|
goto out;
|
|
}
|
|
|
|
if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
|
|
rstc = ERR_PTR(-EINVAL);
|
|
goto out;
|
|
}
|
|
|
|
rstc_id = rcdev->of_xlate(rcdev, &args);
|
|
if (rstc_id < 0) {
|
|
rstc = ERR_PTR(rstc_id);
|
|
goto out;
|
|
}
|
|
|
|
/* reset_list_mutex also protects the rcdev's reset_control list */
|
|
rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);
|
|
|
|
out:
|
|
mutex_unlock(&reset_list_mutex);
|
|
of_node_put(args.np);
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__of_reset_control_get);
|
|
|
|
static struct reset_controller_dev *
|
|
__reset_controller_by_name(const char *name)
|
|
{
|
|
struct reset_controller_dev *rcdev;
|
|
|
|
lockdep_assert_held(&reset_list_mutex);
|
|
|
|
list_for_each_entry(rcdev, &reset_controller_list, list) {
|
|
if (!rcdev->dev)
|
|
continue;
|
|
|
|
if (!strcmp(name, dev_name(rcdev->dev)))
|
|
return rcdev;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct reset_control *
|
|
__reset_control_get_from_lookup(struct device *dev, const char *con_id,
|
|
bool shared, bool optional, bool acquired)
|
|
{
|
|
const struct reset_control_lookup *lookup;
|
|
struct reset_controller_dev *rcdev;
|
|
const char *dev_id = dev_name(dev);
|
|
struct reset_control *rstc = NULL;
|
|
|
|
mutex_lock(&reset_lookup_mutex);
|
|
|
|
list_for_each_entry(lookup, &reset_lookup_list, list) {
|
|
if (strcmp(lookup->dev_id, dev_id))
|
|
continue;
|
|
|
|
if ((!con_id && !lookup->con_id) ||
|
|
((con_id && lookup->con_id) &&
|
|
!strcmp(con_id, lookup->con_id))) {
|
|
mutex_lock(&reset_list_mutex);
|
|
rcdev = __reset_controller_by_name(lookup->provider);
|
|
if (!rcdev) {
|
|
mutex_unlock(&reset_list_mutex);
|
|
mutex_unlock(&reset_lookup_mutex);
|
|
/* Reset provider may not be ready yet. */
|
|
return ERR_PTR(-EPROBE_DEFER);
|
|
}
|
|
|
|
rstc = __reset_control_get_internal(rcdev,
|
|
lookup->index,
|
|
shared, acquired);
|
|
mutex_unlock(&reset_list_mutex);
|
|
break;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&reset_lookup_mutex);
|
|
|
|
if (!rstc)
|
|
return optional ? NULL : ERR_PTR(-ENOENT);
|
|
|
|
return rstc;
|
|
}
|
|
|
|
struct reset_control *__reset_control_get(struct device *dev, const char *id,
|
|
int index, bool shared, bool optional,
|
|
bool acquired)
|
|
{
|
|
if (WARN_ON(shared && acquired))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (dev->of_node)
|
|
return __of_reset_control_get(dev->of_node, id, index, shared,
|
|
optional, acquired);
|
|
|
|
return __reset_control_get_from_lookup(dev, id, shared, optional,
|
|
acquired);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__reset_control_get);
|
|
|
|
int __reset_control_bulk_get(struct device *dev, int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs,
|
|
bool shared, bool optional, bool acquired)
|
|
{
|
|
int ret, i;
|
|
|
|
for (i = 0; i < num_rstcs; i++) {
|
|
rstcs[i].rstc = __reset_control_get(dev, rstcs[i].id, 0,
|
|
shared, optional, acquired);
|
|
if (IS_ERR(rstcs[i].rstc)) {
|
|
ret = PTR_ERR(rstcs[i].rstc);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
mutex_lock(&reset_list_mutex);
|
|
while (i--)
|
|
__reset_control_put_internal(rstcs[i].rstc);
|
|
mutex_unlock(&reset_list_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__reset_control_bulk_get);
|
|
|
|
static void reset_control_array_put(struct reset_control_array *resets)
|
|
{
|
|
int i;
|
|
|
|
mutex_lock(&reset_list_mutex);
|
|
for (i = 0; i < resets->num_rstcs; i++)
|
|
__reset_control_put_internal(resets->rstc[i]);
|
|
mutex_unlock(&reset_list_mutex);
|
|
kfree(resets);
|
|
}
|
|
|
|
/**
|
|
* reset_control_put - free the reset controller
|
|
* @rstc: reset controller
|
|
*/
|
|
void reset_control_put(struct reset_control *rstc)
|
|
{
|
|
if (IS_ERR_OR_NULL(rstc))
|
|
return;
|
|
|
|
if (reset_control_is_array(rstc)) {
|
|
reset_control_array_put(rstc_to_array(rstc));
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&reset_list_mutex);
|
|
__reset_control_put_internal(rstc);
|
|
mutex_unlock(&reset_list_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_put);
|
|
|
|
/**
|
|
* reset_control_bulk_put - free the reset controllers
|
|
* @num_rstcs: number of entries in rstcs array
|
|
* @rstcs: array of struct reset_control_bulk_data with reset controls set
|
|
*/
|
|
void reset_control_bulk_put(int num_rstcs, struct reset_control_bulk_data *rstcs)
|
|
{
|
|
mutex_lock(&reset_list_mutex);
|
|
while (num_rstcs--) {
|
|
if (IS_ERR_OR_NULL(rstcs[num_rstcs].rstc))
|
|
continue;
|
|
__reset_control_put_internal(rstcs[num_rstcs].rstc);
|
|
}
|
|
mutex_unlock(&reset_list_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_bulk_put);
|
|
|
|
static void devm_reset_control_release(struct device *dev, void *res)
|
|
{
|
|
reset_control_put(*(struct reset_control **)res);
|
|
}
|
|
|
|
struct reset_control *
|
|
__devm_reset_control_get(struct device *dev, const char *id, int index,
|
|
bool shared, bool optional, bool acquired)
|
|
{
|
|
struct reset_control **ptr, *rstc;
|
|
|
|
ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
rstc = __reset_control_get(dev, id, index, shared, optional, acquired);
|
|
if (IS_ERR_OR_NULL(rstc)) {
|
|
devres_free(ptr);
|
|
return rstc;
|
|
}
|
|
|
|
*ptr = rstc;
|
|
devres_add(dev, ptr);
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__devm_reset_control_get);
|
|
|
|
struct reset_control_bulk_devres {
|
|
int num_rstcs;
|
|
struct reset_control_bulk_data *rstcs;
|
|
};
|
|
|
|
static void devm_reset_control_bulk_release(struct device *dev, void *res)
|
|
{
|
|
struct reset_control_bulk_devres *devres = res;
|
|
|
|
reset_control_bulk_put(devres->num_rstcs, devres->rstcs);
|
|
}
|
|
|
|
int __devm_reset_control_bulk_get(struct device *dev, int num_rstcs,
|
|
struct reset_control_bulk_data *rstcs,
|
|
bool shared, bool optional, bool acquired)
|
|
{
|
|
struct reset_control_bulk_devres *ptr;
|
|
int ret;
|
|
|
|
ptr = devres_alloc(devm_reset_control_bulk_release, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
ret = __reset_control_bulk_get(dev, num_rstcs, rstcs, shared, optional, acquired);
|
|
if (ret < 0) {
|
|
devres_free(ptr);
|
|
return ret;
|
|
}
|
|
|
|
ptr->num_rstcs = num_rstcs;
|
|
ptr->rstcs = rstcs;
|
|
devres_add(dev, ptr);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__devm_reset_control_bulk_get);
|
|
|
|
/**
|
|
* __device_reset - find reset controller associated with the device
|
|
* and perform reset
|
|
* @dev: device to be reset by the controller
|
|
* @optional: whether it is optional to reset the device
|
|
*
|
|
* Convenience wrapper for __reset_control_get() and reset_control_reset().
|
|
* This is useful for the common case of devices with single, dedicated reset
|
|
* lines.
|
|
*/
|
|
int __device_reset(struct device *dev, bool optional)
|
|
{
|
|
struct reset_control *rstc;
|
|
int ret;
|
|
|
|
rstc = __reset_control_get(dev, NULL, 0, 0, optional, true);
|
|
if (IS_ERR(rstc))
|
|
return PTR_ERR(rstc);
|
|
|
|
ret = reset_control_reset(rstc);
|
|
|
|
reset_control_put(rstc);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__device_reset);
|
|
|
|
/*
|
|
* APIs to manage an array of reset controls.
|
|
*/
|
|
|
|
/**
|
|
* of_reset_control_get_count - Count number of resets available with a device
|
|
*
|
|
* @node: device node that contains 'resets'.
|
|
*
|
|
* Returns positive reset count on success, or error number on failure and
|
|
* on count being zero.
|
|
*/
|
|
static int of_reset_control_get_count(struct device_node *node)
|
|
{
|
|
int count;
|
|
|
|
if (!node)
|
|
return -EINVAL;
|
|
|
|
count = of_count_phandle_with_args(node, "resets", "#reset-cells");
|
|
if (count == 0)
|
|
count = -ENOENT;
|
|
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* of_reset_control_array_get - Get a list of reset controls using
|
|
* device node.
|
|
*
|
|
* @np: device node for the device that requests the reset controls array
|
|
* @shared: whether reset controls are shared or not
|
|
* @optional: whether it is optional to get the reset controls
|
|
* @acquired: only one reset control may be acquired for a given controller
|
|
* and ID
|
|
*
|
|
* Returns pointer to allocated reset_control on success or error on failure
|
|
*/
|
|
struct reset_control *
|
|
of_reset_control_array_get(struct device_node *np, bool shared, bool optional,
|
|
bool acquired)
|
|
{
|
|
struct reset_control_array *resets;
|
|
struct reset_control *rstc;
|
|
int num, i;
|
|
|
|
num = of_reset_control_get_count(np);
|
|
if (num < 0)
|
|
return optional ? NULL : ERR_PTR(num);
|
|
|
|
resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL);
|
|
if (!resets)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
for (i = 0; i < num; i++) {
|
|
rstc = __of_reset_control_get(np, NULL, i, shared, optional,
|
|
acquired);
|
|
if (IS_ERR(rstc))
|
|
goto err_rst;
|
|
resets->rstc[i] = rstc;
|
|
}
|
|
resets->num_rstcs = num;
|
|
resets->base.array = true;
|
|
|
|
return &resets->base;
|
|
|
|
err_rst:
|
|
mutex_lock(&reset_list_mutex);
|
|
while (--i >= 0)
|
|
__reset_control_put_internal(resets->rstc[i]);
|
|
mutex_unlock(&reset_list_mutex);
|
|
|
|
kfree(resets);
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_reset_control_array_get);
|
|
|
|
/**
|
|
* devm_reset_control_array_get - Resource managed reset control array get
|
|
*
|
|
* @dev: device that requests the list of reset controls
|
|
* @shared: whether reset controls are shared or not
|
|
* @optional: whether it is optional to get the reset controls
|
|
*
|
|
* The reset control array APIs are intended for a list of resets
|
|
* that just have to be asserted or deasserted, without any
|
|
* requirements on the order.
|
|
*
|
|
* Returns pointer to allocated reset_control on success or error on failure
|
|
*/
|
|
struct reset_control *
|
|
devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
|
|
{
|
|
struct reset_control **ptr, *rstc;
|
|
|
|
ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);
|
|
if (IS_ERR_OR_NULL(rstc)) {
|
|
devres_free(ptr);
|
|
return rstc;
|
|
}
|
|
|
|
*ptr = rstc;
|
|
devres_add(dev, ptr);
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
|
|
|
|
static int reset_control_get_count_from_lookup(struct device *dev)
|
|
{
|
|
const struct reset_control_lookup *lookup;
|
|
const char *dev_id;
|
|
int count = 0;
|
|
|
|
if (!dev)
|
|
return -EINVAL;
|
|
|
|
dev_id = dev_name(dev);
|
|
mutex_lock(&reset_lookup_mutex);
|
|
|
|
list_for_each_entry(lookup, &reset_lookup_list, list) {
|
|
if (!strcmp(lookup->dev_id, dev_id))
|
|
count++;
|
|
}
|
|
|
|
mutex_unlock(&reset_lookup_mutex);
|
|
|
|
if (count == 0)
|
|
count = -ENOENT;
|
|
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* reset_control_get_count - Count number of resets available with a device
|
|
*
|
|
* @dev: device for which to return the number of resets
|
|
*
|
|
* Returns positive reset count on success, or error number on failure and
|
|
* on count being zero.
|
|
*/
|
|
int reset_control_get_count(struct device *dev)
|
|
{
|
|
if (dev->of_node)
|
|
return of_reset_control_get_count(dev->of_node);
|
|
|
|
return reset_control_get_count_from_lookup(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_get_count);
|