3  * Reset Controller framework
15 #include <linux/reset.h>
16 #include <linux/reset-controller.h>
26  * struct reset_control - a reset control
27  * @rcdev: a pointer to the reset controller device
28  *         this reset control belongs to
29  * @list: list entry for the rcdev's reset controller list
30  * @id: ID of the reset controller in the reset
35  * @deassert_cnt: Number of times this reset line has been deasserted
36  * @triggered_count: Number of times this reset line has been reset. Currently
53  * struct reset_control_array - an array of reset controls
54  * @base: reset control for compatibility with reset control API functions
55  * @num_rstcs: number of reset controls
56  * @rstc: array of reset controls
76  * of_reset_simple_xlate - translate reset_spec to the reset line number
77  * @rcdev: a pointer to the reset controller device
78  * @reset_spec: reset line specifier as found in the device tree
80  * This simple translation function should be used for reset controllers
81  * with 1:1 mapping, where reset lines can be indexed by number without gaps.
93  * reset_controller_register - register a reset controller device
94  * @rcdev: a pointer to the initialized reset controller device
114  * reset_controller_unregister - unregister a reset controller device
115  * @rcdev: a pointer to the reset controller device
132  * @dev: device that is registering this reset controller
133  * @rcdev: a pointer to the initialized reset controller device
135  * Managed reset_controller_register(). For reset controllers registered by
164  * @lookup: array of reset lookup entries
178 			pr_warn("%s(): reset lookup entry badly specified, skipping\n",  in reset_controller_add_lookup()
277  * reset_control_reset - reset the controlled device
278  * @rstc: reset controller
280  * On a shared reset line the actual reset pulse is only triggered once for the
283  * Consumers must not use reset_control_(de)assert on shared reset lines when
286  * If rstc is NULL it is an optional reset and the function will just
302 	if (!rstc->rcdev->ops->reset)  in reset_control_reset()
316 	ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);  in reset_control_reset()
325  * reset_control_assert - asserts the reset line
326  * @rstc: reset controller
328  * Calling this on an exclusive reset controller guarantees that the reset
329  * will be asserted. When called on a shared reset controller the line may
332  * For shared reset controls a driver cannot expect the hw's registers and
333  * internal state to be reset, but must be prepared for this to happen.
334  * Consumers must not use reset_control_reset on shared reset lines when
338  * If rstc is NULL it is an optional reset and the function will just
363 		 * Shared reset controls allow the reset line to be in any state  in reset_control_assert()
370 		 * If the reset controller does not implement .assert(), there  in reset_control_assert()
371 		 * is no way to guarantee that the reset line is asserted after  in reset_control_assert()
378 			WARN(1, "reset %s (ID: %u) is not acquired\n",  in reset_control_assert()
389  * reset_control_deassert - deasserts the reset line
390  * @rstc: reset controller
392  * After calling this function, the reset is guaranteed to be deasserted.
393  * Consumers must not use reset_control_reset on shared reset lines when
397  * If rstc is NULL it is an optional reset and the function will just
419 			WARN(1, "reset %s (ID: %u) is not acquired\n",  in reset_control_deassert()
426 	 * If the reset controller does not implement .deassert(), we assume  in reset_control_deassert()
427 	 * that it handles self-deasserting reset lines via .reset(). In that  in reset_control_deassert()
428 	 * case, the reset lines are deasserted by default. If that is not the  in reset_control_deassert()
429 	 * case, the reset controller driver should implement .deassert() and  in reset_control_deassert()
441  * positive value if the reset line is asserted, or zero if the reset
442  * line is not asserted or if the desc is NULL (optional reset).
443  * @rstc: reset controller
461  * reset_control_acquire() - acquires a reset control for exclusive use
462  * @rstc: reset control
464  * This is used to explicitly acquire a reset control for exclusive use. Note
466  * second consumer to be able to control the reset, the first consumer has to
468  * reset_control_get_exclusive_released() to obtain an instance of the reset
469  * control. Such reset controls are not acquired by default.
471  * Consumers implementing shared access to an exclusive reset need to follow
473  * a reset they must acquire exclusive access using reset_control_acquire().
474  * After they are done operating the reset, they must release exclusive access
476  * access to the reset as long as another consumer hasn't released a reset.
517  * reset_control_release() - releases exclusive access to a reset control
518  * @rstc: reset control
520  * Releases exclusive access right to a reset control previously obtained by a
551 			 * controlled reset line.  in __reset_control_get_internal()
615 						 "reset-names", id);  in __of_reset_control_get()
622 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",  in __of_reset_control_get()
706 				/* Reset provider may not be ready yet. */  in __reset_control_get_from_lookup()
754  * reset_control_put - free the reset controller
755  * @rstc: reset controller
802  * device_reset - find reset controller associated with the device
803  *                and perform reset
804  * @dev: device to be reset by the controller
805  * @optional: whether it is optional to reset the device
808  * This is useful for the common case of devices with single, dedicated reset
829  * APIs to manage an array of reset controls.
837  * Returns positive reset count on success, or error number on failure and
847 	count = of_count_phandle_with_args(node, "resets", "#reset-cells");  in of_reset_control_get_count()
855  * of_reset_control_array_get - Get a list of reset controls using
858  * @np: device node for the device that requests the reset controls array
859  * @shared: whether reset controls are shared or not
860  * @optional: whether it is optional to get the reset controls
861  * @acquired: only one reset control may be acquired for a given controller
908  * devm_reset_control_array_get - Resource managed reset control array get
910  * @dev: device that requests the list of reset controls
911  * @shared: whether reset controls are shared or not
912  * @optional: whether it is optional to get the reset controls
914  * The reset control array APIs are intended for a list of resets
975  * Returns positive reset count on success, or error number on failure and