Merge branch 'reset/acquire' of git://git.pengutronix.de/git/pza/linux into drm/tegra/for-next (ee222c5d) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/reset/core.c

+166 −14

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@ static LIST_HEAD(reset_lookup_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?
		* @deassert_cnt: Number of times this reset line has been deasserted
		* @triggered_count: Number of times this reset line has been reset. Currently
		@@ -45,6 +46,7 @@ struct reset_control {
		struct list_head list;
		unsigned int id;
		struct kref refcnt;
		bool acquired;
		bool shared;
		bool array;
		atomic_t deassert_count;
		@@ -63,6 +65,17 @@ struct reset_control_array {
		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
		@@ -232,6 +245,34 @@ static int reset_control_array_deassert(struct reset_control_array *resets)
		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;
		@@ -272,6 +313,9 @@ int reset_control_reset(struct reset_control *rstc)

		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);
		@@ -334,6 +378,12 @@ int reset_control_assert(struct reset_control *rstc)
		*/
		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);
		@@ -369,6 +419,12 @@ int reset_control_deassert(struct reset_control *rstc)

		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;
		}
		}

		/*
		@@ -406,9 +462,87 @@ int reset_control_status(struct reset_control *rstc)
		}
		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_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);

		static struct reset_control *__reset_control_get_internal(
		struct reset_controller_dev *rcdev,
		unsigned int index, bool shared)
		unsigned int index, bool shared, bool acquired)
		{
		struct reset_control *rstc;

		@@ -416,6 +550,14 @@ static struct reset_control *__reset_control_get_internal(

		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);

		@@ -434,6 +576,7 @@ static struct reset_control *__reset_control_get_internal(
		list_add(&rstc->list, &rcdev->reset_control_head);
		rstc->id = index;
		kref_init(&rstc->refcnt);
		rstc->acquired = acquired;
		rstc->shared = shared;

		return rstc;
		@@ -461,7 +604,7 @@ static void __reset_control_put_internal(struct reset_control *rstc)

		struct reset_control __of_reset_control_get(struct device_node node,
		const char *id, int index, bool shared,
		bool optional)
		bool optional, bool acquired)
		{
		struct reset_control *rstc;
		struct reset_controller_dev r, rcdev;
		@@ -514,7 +657,7 @@ struct reset_control __of_reset_control_get(struct device_node node,
		}

		/* reset_list_mutex also protects the rcdev's reset_control list */
		rstc = __reset_control_get_internal(rcdev, rstc_id, shared);
		rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);

		out:
		mutex_unlock(&reset_list_mutex);
		@@ -544,7 +687,7 @@ __reset_controller_by_name(const char *name)

		static struct reset_control *
		__reset_control_get_from_lookup(struct device dev, const char con_id,
		bool shared, bool optional)
		bool shared, bool optional, bool acquired)
		{
		const struct reset_control_lookup *lookup;
		struct reset_controller_dev *rcdev;
		@@ -574,7 +717,7 @@ __reset_control_get_from_lookup(struct device dev, const char con_id,

		rstc = __reset_control_get_internal(rcdev,
		lookup->index,
		shared);
		shared, acquired);
		mutex_unlock(&reset_list_mutex);
		break;
		}
		@@ -589,13 +732,18 @@ __reset_control_get_from_lookup(struct device dev, const char con_id,
		}

		struct reset_control __reset_control_get(struct device dev, const char *id,
		int index, bool shared, bool optional)
		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);
		optional, acquired);

		return __reset_control_get_from_lookup(dev, id, shared, optional);
		return __reset_control_get_from_lookup(dev, id, shared, optional,
		acquired);
		}
		EXPORT_SYMBOL_GPL(__reset_control_get);

		@@ -636,7 +784,7 @@ static void devm_reset_control_release(struct device dev, void res)

		struct reset_control __devm_reset_control_get(struct device dev,
		const char *id, int index, bool shared,
		bool optional)
		bool optional, bool acquired)
		{
		struct reset_control *ptr, rstc;

		@@ -645,7 +793,7 @@ struct reset_control __devm_reset_control_get(struct device dev,
		if (!ptr)
		return ERR_PTR(-ENOMEM);

		rstc = __reset_control_get(dev, id, index, shared, optional);
		rstc = __reset_control_get(dev, id, index, shared, optional, acquired);
		if (!IS_ERR(rstc)) {
		*ptr = rstc;
		devres_add(dev, ptr);
		@@ -672,7 +820,7 @@ int __device_reset(struct device *dev, bool optional)
		struct reset_control *rstc;
		int ret;

		rstc = __reset_control_get(dev, NULL, 0, 0, optional);
		rstc = __reset_control_get(dev, NULL, 0, 0, optional, true);
		if (IS_ERR(rstc))
		return PTR_ERR(rstc);

		@@ -716,12 +864,15 @@ static int of_reset_control_get_count(struct device_node *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_array on success or
		* error on failure
		*/
		struct reset_control *
		of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
		of_reset_control_array_get(struct device_node *np, bool shared, bool optional,
		bool acquired)
		{
		struct reset_control_array *resets;
		struct reset_control *rstc;
		@@ -736,7 +887,8 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
		return ERR_PTR(-ENOMEM);

		for (i = 0; i < num; i++) {
		rstc = __of_reset_control_get(np, NULL, i, shared, optional);
		rstc = __of_reset_control_get(np, NULL, i, shared, optional,
		acquired);
		if (IS_ERR(rstc))
		goto err_rst;
		resets->rstc[i] = rstc;
		@@ -783,7 +935,7 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
		if (!devres)
		return ERR_PTR(-ENOMEM);

		rstc = of_reset_control_array_get(dev->of_node, shared, optional);
		rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);
		if (IS_ERR(rstc)) {
		devres_free(devres);
		return rstc;

drivers/usb/dwc3/dwc3-of-simple.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -107,7 +107,8 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
		simple->pulse_resets = true;
		}

		simple->resets = of_reset_control_array_get(np, shared_resets, true);
		simple->resets = of_reset_control_array_get(np, shared_resets, true,
		true);
		if (IS_ERR(simple->resets)) {
		ret = PTR_ERR(simple->resets);
		dev_err(dev, "failed to get device resets, err=%d\n", ret);

include/linux/reset.h

+87 −26

Original line number	Diff line number	Diff line
		@@ -14,23 +14,26 @@ int reset_control_reset(struct reset_control *rstc);
		int reset_control_assert(struct reset_control *rstc);
		int reset_control_deassert(struct reset_control *rstc);
		int reset_control_status(struct reset_control *rstc);
		int reset_control_acquire(struct reset_control *rstc);
		void reset_control_release(struct reset_control *rstc);

		struct reset_control __of_reset_control_get(struct device_node node,
		const char *id, int index, bool shared,
		bool optional);
		bool optional, bool acquired);
		struct reset_control __reset_control_get(struct device dev, const char *id,
		int index, bool shared,
		bool optional);
		bool optional, bool acquired);
		void reset_control_put(struct reset_control *rstc);
		int __device_reset(struct device *dev, bool optional);
		struct reset_control __devm_reset_control_get(struct device dev,
		const char *id, int index, bool shared,
		bool optional);
		bool optional, bool acquired);

		struct reset_control devm_reset_control_array_get(struct device dev,
		bool shared, bool optional);
		struct reset_control of_reset_control_array_get(struct device_node np,
		bool shared, bool optional);
		bool shared, bool optional,
		bool acquired);

		int reset_control_get_count(struct device *dev);

		@@ -56,6 +59,15 @@ static inline int reset_control_status(struct reset_control *rstc)
		return 0;
		}

		static inline int reset_control_acquire(struct reset_control *rstc)
		{
		return 0;
		}

		static inline void reset_control_release(struct reset_control *rstc)
		{
		}

		static inline void reset_control_put(struct reset_control *rstc)
		{
		}
		@@ -68,21 +80,23 @@ static inline int __device_reset(struct device *dev, bool optional)
		static inline struct reset_control *__of_reset_control_get(
		struct device_node *node,
		const char *id, int index, bool shared,
		bool optional)
		bool optional, bool acquired)
		{
		return optional ? NULL : ERR_PTR(-ENOTSUPP);
		}

		static inline struct reset_control *__reset_control_get(
		struct device dev, const char id,
		int index, bool shared, bool optional)
		int index, bool shared, bool optional,
		bool acquired)
		{
		return optional ? NULL : ERR_PTR(-ENOTSUPP);
		}

		static inline struct reset_control *__devm_reset_control_get(
		struct device dev, const char id,
		int index, bool shared, bool optional)
		int index, bool shared, bool optional,
		bool acquired)
		{
		return optional ? NULL : ERR_PTR(-ENOTSUPP);
		}
		@@ -94,7 +108,8 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
		}

		static inline struct reset_control *
		of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
		of_reset_control_array_get(struct device_node *np, bool shared, bool optional,
		bool acquired)
		{
		return optional ? NULL : ERR_PTR(-ENOTSUPP);
		}
		@@ -134,7 +149,28 @@ static inline int device_reset_optional(struct device *dev)
		static inline struct reset_control *
		__must_check reset_control_get_exclusive(struct device dev, const char id)
		{
		return __reset_control_get(dev, id, 0, false, false);
		return __reset_control_get(dev, id, 0, false, false, true);
		}

		/**
		* reset_control_get_exclusive_released - Lookup and obtain a temoprarily
		* exclusive reference to a reset
		* controller.
		* @dev: device to be reset by the controller
		* @id: reset line name
		*
		* Returns a struct reset_control or IS_ERR() condition containing errno.
		* reset-controls returned by this function must be acquired via
		* reset_control_acquire() before they can be used and should be released
		* via reset_control_release() afterwards.
		*
		* Use of id names is optional.
		*/
		static inline struct reset_control *
		__must_check reset_control_get_exclusive_released(struct device *dev,
		const char *id)
		{
		return __reset_control_get(dev, id, 0, false, false, false);
		}

		/**
		@@ -162,19 +198,19 @@ __must_check reset_control_get_exclusive(struct device dev, const char id)
		static inline struct reset_control *reset_control_get_shared(
		struct device dev, const char id)
		{
		return __reset_control_get(dev, id, 0, true, false);
		return __reset_control_get(dev, id, 0, true, false, false);
		}

		static inline struct reset_control *reset_control_get_optional_exclusive(
		struct device dev, const char id)
		{
		return __reset_control_get(dev, id, 0, false, true);
		return __reset_control_get(dev, id, 0, false, true, true);
		}

		static inline struct reset_control *reset_control_get_optional_shared(
		struct device dev, const char id)
		{
		return __reset_control_get(dev, id, 0, true, true);
		return __reset_control_get(dev, id, 0, true, true, false);
		}

		/**
		@@ -190,7 +226,7 @@ static inline struct reset_control *reset_control_get_optional_shared(
		static inline struct reset_control *of_reset_control_get_exclusive(
		struct device_node node, const char id)
		{
		return __of_reset_control_get(node, id, 0, false, false);
		return __of_reset_control_get(node, id, 0, false, false, true);
		}

		/**
		@@ -215,7 +251,7 @@ static inline struct reset_control *of_reset_control_get_exclusive(
		static inline struct reset_control *of_reset_control_get_shared(
		struct device_node node, const char id)
		{
		return __of_reset_control_get(node, id, 0, true, false);
		return __of_reset_control_get(node, id, 0, true, false, false);
		}

		/**
		@@ -232,7 +268,7 @@ static inline struct reset_control *of_reset_control_get_shared(
		static inline struct reset_control *of_reset_control_get_exclusive_by_index(
		struct device_node *node, int index)
		{
		return __of_reset_control_get(node, NULL, index, false, false);
		return __of_reset_control_get(node, NULL, index, false, false, true);
		}

		/**
		@@ -260,7 +296,7 @@ static inline struct reset_control *of_reset_control_get_exclusive_by_index(
		static inline struct reset_control *of_reset_control_get_shared_by_index(
		struct device_node *node, int index)
		{
		return __of_reset_control_get(node, NULL, index, true, false);
		return __of_reset_control_get(node, NULL, index, true, false, false);
		}

		/**
		@@ -279,7 +315,26 @@ static inline struct reset_control *
		__must_check devm_reset_control_get_exclusive(struct device *dev,
		const char *id)
		{
		return __devm_reset_control_get(dev, id, 0, false, false);
		return __devm_reset_control_get(dev, id, 0, false, false, true);
		}

		/**
		* devm_reset_control_get_exclusive_released - resource managed
		* reset_control_get_exclusive_released()
		* @dev: device to be reset by the controller
		* @id: reset line name
		*
		* Managed reset_control_get_exclusive_released(). For reset controllers
		* returned from this function, reset_control_put() is called automatically on
		* driver detach.
		*
		* See reset_control_get_exclusive_released() for more information.
		*/
		static inline struct reset_control *
		__must_check devm_reset_control_get_exclusive_released(struct device *dev,
		const char *id)
		{
		return __devm_reset_control_get(dev, id, 0, false, false, false);
		}

		/**
		@@ -294,19 +349,19 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
		static inline struct reset_control *devm_reset_control_get_shared(
		struct device dev, const char id)
		{
		return __devm_reset_control_get(dev, id, 0, true, false);
		return __devm_reset_control_get(dev, id, 0, true, false, false);
		}

		static inline struct reset_control *devm_reset_control_get_optional_exclusive(
		struct device dev, const char id)
		{
		return __devm_reset_control_get(dev, id, 0, false, true);
		return __devm_reset_control_get(dev, id, 0, false, true, true);
		}

		static inline struct reset_control *devm_reset_control_get_optional_shared(
		struct device dev, const char id)
		{
		return __devm_reset_control_get(dev, id, 0, true, true);
		return __devm_reset_control_get(dev, id, 0, true, true, false);
		}

		/**
		@@ -324,7 +379,7 @@ static inline struct reset_control *devm_reset_control_get_optional_shared(
		static inline struct reset_control *
		devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
		{
		return __devm_reset_control_get(dev, NULL, index, false, false);
		return __devm_reset_control_get(dev, NULL, index, false, false, true);
		}

		/**
		@@ -340,7 +395,7 @@ devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
		static inline struct reset_control *
		devm_reset_control_get_shared_by_index(struct device *dev, int index)
		{
		return __devm_reset_control_get(dev, NULL, index, true, false);
		return __devm_reset_control_get(dev, NULL, index, true, false, false);
		}

		/*
		@@ -412,24 +467,30 @@ devm_reset_control_array_get_optional_shared(struct device *dev)
		static inline struct reset_control *
		of_reset_control_array_get_exclusive(struct device_node *node)
		{
		return of_reset_control_array_get(node, false, false);
		return of_reset_control_array_get(node, false, false, true);
		}

		static inline struct reset_control *
		of_reset_control_array_get_exclusive_released(struct device_node *node)
		{
		return of_reset_control_array_get(node, false, false, false);
		}

		static inline struct reset_control *
		of_reset_control_array_get_shared(struct device_node *node)
		{
		return of_reset_control_array_get(node, true, false);
		return of_reset_control_array_get(node, true, false, true);
		}

		static inline struct reset_control *
		of_reset_control_array_get_optional_exclusive(struct device_node *node)
		{
		return of_reset_control_array_get(node, false, true);
		return of_reset_control_array_get(node, false, true, true);
		}

		static inline struct reset_control *
		of_reset_control_array_get_optional_shared(struct device_node *node)
		{
		return of_reset_control_array_get(node, true, true);
		return of_reset_control_array_get(node, true, true, true);
		}
		#endif