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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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/acpi.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. _RST firmware method will be called for devices with ACPI.
  */
 int __device_reset(struct device *dev, bool optional)
 {
     struct reset_control *rstc;
     int ret;
 
 #ifdef CONFIG_ACPI
     acpi_handle handle = ACPI_HANDLE(dev);
 
     if (handle) {
         if (!acpi_has_method(handle, "_RST"))
             return optional ? 0 : -ENOENT;
         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL,
                               NULL)))
             return -EIO;
     }
 #endif
 
     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);

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