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- #include <linux/atomic.h>
- #include <linux/device.h>
- #include <linux/err.h>
- #include <linux/export.h>
- #include <linux/kernel.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);
- struct reset_control {
- struct reset_controller_dev *rcdev;
- struct list_head list;
- unsigned int id;
- unsigned int refcnt;
- int shared;
- atomic_t deassert_count;
- };
- 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];
- }
- 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);
- 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);
- }
- 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) {
- *rcdevp = rcdev;
- devres_add(dev, rcdevp);
- } else {
- devres_free(rcdevp);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(devm_reset_controller_register);
- int reset_control_reset(struct reset_control *rstc)
- {
- if (!rstc)
- return 0;
- if (WARN_ON(IS_ERR(rstc)))
- return -EINVAL;
- if (rstc->rcdev->ops->reset)
- return rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
- return -ENOTSUPP;
- }
- EXPORT_SYMBOL_GPL(reset_control_reset);
- int reset_control_assert(struct reset_control *rstc)
- {
- if (!rstc)
- return 0;
- if (WARN_ON(IS_ERR(rstc)))
- return -EINVAL;
- if (!rstc->rcdev->ops->assert)
- return -ENOTSUPP;
- if (rstc->shared) {
- if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))
- return -EINVAL;
- if (atomic_dec_return(&rstc->deassert_count) != 0)
- return 0;
- }
- return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
- }
- EXPORT_SYMBOL_GPL(reset_control_assert);
- int reset_control_deassert(struct reset_control *rstc)
- {
- if (!rstc)
- return 0;
- if (WARN_ON(IS_ERR(rstc)))
- return -EINVAL;
- if (!rstc->rcdev->ops->deassert)
- return -ENOTSUPP;
- if (rstc->shared) {
- if (atomic_inc_return(&rstc->deassert_count) != 1)
- return 0;
- }
- return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
- }
- EXPORT_SYMBOL_GPL(reset_control_deassert);
- int reset_control_status(struct reset_control *rstc)
- {
- if (!rstc)
- return 0;
- if (WARN_ON(IS_ERR(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);
- static struct reset_control *__reset_control_get_internal(
- struct reset_controller_dev *rcdev,
- unsigned int index, int shared)
- {
- struct reset_control *rstc;
- lockdep_assert_held(&reset_list_mutex);
- list_for_each_entry(rstc, &rcdev->reset_control_head, list) {
- if (rstc->id == index) {
- if (WARN_ON(!rstc->shared || !shared))
- return ERR_PTR(-EBUSY);
- rstc->refcnt++;
- return rstc;
- }
- }
- rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
- if (!rstc)
- return ERR_PTR(-ENOMEM);
- try_module_get(rcdev->owner);
- rstc->rcdev = rcdev;
- list_add(&rstc->list, &rcdev->reset_control_head);
- rstc->id = index;
- rstc->refcnt = 1;
- rstc->shared = shared;
- return rstc;
- }
- static void __reset_control_put_internal(struct reset_control *rstc)
- {
- lockdep_assert_held(&reset_list_mutex);
- if (--rstc->refcnt)
- return;
- module_put(rstc->rcdev->owner);
- list_del(&rstc->list);
- kfree(rstc);
- }
- struct reset_control *__of_reset_control_get(struct device_node *node,
- const char *id, int index, bool shared,
- bool optional)
- {
- 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;
- }
- }
- of_node_put(args.np);
- if (!rcdev) {
- mutex_unlock(&reset_list_mutex);
- return ERR_PTR(-EPROBE_DEFER);
- }
- if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
- mutex_unlock(&reset_list_mutex);
- return ERR_PTR(-EINVAL);
- }
- rstc_id = rcdev->of_xlate(rcdev, &args);
- if (rstc_id < 0) {
- mutex_unlock(&reset_list_mutex);
- return ERR_PTR(rstc_id);
- }
-
- rstc = __reset_control_get_internal(rcdev, rstc_id, shared);
- mutex_unlock(&reset_list_mutex);
- return rstc;
- }
- EXPORT_SYMBOL_GPL(__of_reset_control_get);
- struct reset_control *__reset_control_get(struct device *dev, const char *id,
- int index, bool shared, bool optional)
- {
- if (dev->of_node)
- return __of_reset_control_get(dev->of_node, id, index, shared,
- optional);
- return optional ? NULL : ERR_PTR(-EINVAL);
- }
- EXPORT_SYMBOL_GPL(__reset_control_get);
- void reset_control_put(struct reset_control *rstc)
- {
- if (IS_ERR_OR_NULL(rstc))
- return;
- mutex_lock(&reset_list_mutex);
- __reset_control_put_internal(rstc);
- mutex_unlock(&reset_list_mutex);
- }
- EXPORT_SYMBOL_GPL(reset_control_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)
- {
- 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);
- if (!IS_ERR(rstc)) {
- *ptr = rstc;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
- return rstc;
- }
- EXPORT_SYMBOL_GPL(__devm_reset_control_get);
- int __device_reset(struct device *dev, bool optional)
- {
- struct reset_control *rstc;
- int ret;
- rstc = __reset_control_get(dev, NULL, 0, 0, optional);
- if (IS_ERR(rstc))
- return PTR_ERR(rstc);
- ret = reset_control_reset(rstc);
- reset_control_put(rstc);
- return ret;
- }
- EXPORT_SYMBOL_GPL(__device_reset);
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