1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * coupler.h -- SoC Regulator support, coupler API.
4  *
5  * Regulator Coupler Interface.
6  */
7 
8 #ifndef __LINUX_REGULATOR_COUPLER_H_
9 #define __LINUX_REGULATOR_COUPLER_H_
10 
11 #include <linux/kernel.h>
12 #include <linux/suspend.h>
13 
14 struct regulator_coupler;
15 struct regulator_dev;
16 
17 /**
18  * struct regulator_coupler - customized regulator's coupler
19  *
20  * Regulator's coupler allows to customize coupling algorithm.
21  *
22  * @list: couplers list entry
23  * @attach_regulator: Callback invoked on creation of a coupled regulator,
24  *                    couples are unresolved at this point. The callee should
25  *                    check that it could handle the regulator and return 0 on
26  *                    success, -errno on failure and 1 if given regulator is
27  *                    not suitable for this coupler (case of having multiple
28  *                    regulators in a system). Callback shall be implemented.
29  * @detach_regulator: Callback invoked on destruction of a coupled regulator.
30  *                    This callback is optional and could be NULL.
31  * @balance_voltage: Callback invoked when voltage of a coupled regulator is
32  *                   changing. Called with all of the coupled rdev's being held
33  *                   under "consumer lock". The callee should perform voltage
34  *                   balancing, changing voltage of the coupled regulators as
35  *                   needed. It's up to the coupler to verify the voltage
36  *                   before changing it in hardware, i.e. coupler should
37  *                   check consumer's min/max and etc. This callback is
38  *                   optional and could be NULL, in which case a generic
39  *                   voltage balancer will be used.
40  */
41 struct regulator_coupler {
42 	struct list_head list;
43 
44 	int (*attach_regulator)(struct regulator_coupler *coupler,
45 				struct regulator_dev *rdev);
46 	int (*detach_regulator)(struct regulator_coupler *coupler,
47 				struct regulator_dev *rdev);
48 	int (*balance_voltage)(struct regulator_coupler *coupler,
49 			       struct regulator_dev *rdev,
50 			       suspend_state_t state);
51 };
52 
53 #ifdef CONFIG_REGULATOR
54 int regulator_coupler_register(struct regulator_coupler *coupler);
55 const char *rdev_get_name(struct regulator_dev *rdev);
56 int regulator_check_consumers(struct regulator_dev *rdev,
57 			      int *min_uV, int *max_uV,
58 			      suspend_state_t state);
59 int regulator_check_voltage(struct regulator_dev *rdev,
60 			    int *min_uV, int *max_uV);
61 int regulator_get_voltage_rdev(struct regulator_dev *rdev);
62 int regulator_set_voltage_rdev(struct regulator_dev *rdev,
63 			       int min_uV, int max_uV,
64 			       suspend_state_t state);
65 #else
66 static inline int regulator_coupler_register(struct regulator_coupler *coupler)
67 {
68 	return 0;
69 }
70 static inline const char *rdev_get_name(struct regulator_dev *rdev)
71 {
72 	return NULL;
73 }
74 static inline int regulator_check_consumers(struct regulator_dev *rdev,
75 					    int *min_uV, int *max_uV,
76 					    suspend_state_t state)
77 {
78 	return -EINVAL;
79 }
80 static inline int regulator_check_voltage(struct regulator_dev *rdev,
81 					  int *min_uV, int *max_uV)
82 {
83 	return -EINVAL;
84 }
85 static inline int regulator_get_voltage_rdev(struct regulator_dev *rdev)
86 {
87 	return -EINVAL;
88 }
89 static inline int regulator_set_voltage_rdev(struct regulator_dev *rdev,
90 					     int min_uV, int max_uV,
91 					     suspend_state_t state)
92 {
93 	return -EINVAL;
94 }
95 #endif
96 
97 #endif
98