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Tom Rini10e47792018-05-06 17:58:06 -04001/* SPDX-License-Identifier: GPL-2.0 */
Stephen Warren92c67fa2016-07-13 13:45:31 -06002/*
3 * Copyright (c) 2016, NVIDIA CORPORATION.
Stephen Warren92c67fa2016-07-13 13:45:31 -06004 */
5
6#ifndef _POWER_DOMAIN_H
7#define _POWER_DOMAIN_H
8
9/**
10 * A power domain is a portion of an SoC or chip that is powered by a
11 * switchable source of power. In many cases, software has control over the
12 * power domain, and can turn the power source on or off. This is typically
13 * done to save power by powering off unused devices, or to enable software
14 * sequencing of initial powerup at boot. This API provides a means for
15 * drivers to turn power domains on and off.
16 *
17 * A driver that implements UCLASS_POWER_DOMAIN is a power domain controller or
18 * provider. A controller will often implement multiple separate power domains,
19 * since the hardware it manages often has this capability.
20 * power-domain-uclass.h describes the interface which power domain controllers
21 * must implement.
22 *
23 * Depending on the power domain controller hardware, changing the state of a
24 * power domain may require performing related operations on other resources.
25 * For example, some power domains may require certain clocks to be enabled
26 * whenever the power domain is powered on, or during the time when the power
27 * domain is transitioning state. These details are implementation-specific
28 * and should ideally be encapsulated entirely within the provider driver, or
29 * configured through mechanisms (e.g. device tree) that do not require client
30 * drivers to provide extra configuration information.
31 *
32 * Power domain consumers/clients are the drivers for HW modules within the
33 * power domain. This header file describes the API used by those drivers.
34 *
35 * In many cases, a single complex IO controller (e.g. a PCIe controller) will
36 * be the sole logic contained within a power domain. In such cases, it is
37 * logical for the relevant device driver to directly control that power
38 * domain. In other cases, multiple controllers, each with their own driver,
39 * may be contained in a single power domain. Any logic require to co-ordinate
40 * between drivers for these multiple controllers is beyond the scope of this
41 * API at present. Equally, this API does not define or implement any policy
42 * by which power domains are managed.
43 */
44
45struct udevice;
46
47/**
48 * struct power_domain - A handle to (allowing control of) a single power domain.
49 *
50 * Clients provide storage for power domain handles. The content of the
51 * structure is managed solely by the power domain API and power domain
52 * drivers. A power domain struct is initialized by "get"ing the power domain
53 * struct. The power domain struct is passed to all other power domain APIs to
54 * identify which power domain to operate upon.
55 *
56 * @dev: The device which implements the power domain.
57 * @id: The power domain ID within the provider.
Lokesh Vutla987ae662019-06-07 19:24:44 +053058 * @priv: Private data corresponding to each power domain.
Stephen Warren92c67fa2016-07-13 13:45:31 -060059 */
60struct power_domain {
61 struct udevice *dev;
Stephen Warren92c67fa2016-07-13 13:45:31 -060062 unsigned long id;
Lokesh Vutla987ae662019-06-07 19:24:44 +053063 void *priv;
Stephen Warren92c67fa2016-07-13 13:45:31 -060064};
65
66/**
67 * power_domain_get - Get/request the power domain for a device.
68 *
69 * This looks up and requests a power domain. Each device is assumed to have
70 * a single (or, at least one) power domain associated with it somehow, and
71 * that domain, or the first/default domain. The mapping of client device to
72 * provider power domain may be via device-tree properties, board-provided
73 * mapping tables, or some other mechanism.
74 *
75 * @dev: The client device.
76 * @power_domain A pointer to a power domain struct to initialize.
77 * @return 0 if OK, or a negative error code.
78 */
Peng Fan57965702018-07-27 10:20:36 +080079#if CONFIG_IS_ENABLED(POWER_DOMAIN)
Stephen Warren92c67fa2016-07-13 13:45:31 -060080int power_domain_get(struct udevice *dev, struct power_domain *power_domain);
Peng Fan57965702018-07-27 10:20:36 +080081#else
82static inline
83int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
84{
85 return -ENOSYS;
86}
87#endif
Stephen Warren92c67fa2016-07-13 13:45:31 -060088
89/**
Lokesh Vutlac411c672018-08-27 15:57:44 +053090 * power_domain_get_by_index - Get the indexed power domain for a device.
91 *
92 * @dev: The client device.
93 * @power_domain: A pointer to a power domain struct to initialize.
94 * @index: Power domain index to be powered on.
95 *
96 * @return 0 if OK, or a negative error code.
97 */
98#if CONFIG_IS_ENABLED(POWER_DOMAIN)
99int power_domain_get_by_index(struct udevice *dev,
100 struct power_domain *power_domain, int index);
101#else
102static inline
103int power_domain_get_by_index(struct udevice *dev,
104 struct power_domain *power_domain, int index)
105{
106 return -ENOSYS;
107}
108#endif
109
110/**
Stephen Warren92c67fa2016-07-13 13:45:31 -0600111 * power_domain_free - Free a previously requested power domain.
112 *
113 * @power_domain: A power domain struct that was previously successfully
114 * requested by power_domain_get().
115 * @return 0 if OK, or a negative error code.
116 */
Peng Fan57965702018-07-27 10:20:36 +0800117#if CONFIG_IS_ENABLED(POWER_DOMAIN)
Stephen Warren92c67fa2016-07-13 13:45:31 -0600118int power_domain_free(struct power_domain *power_domain);
Peng Fan57965702018-07-27 10:20:36 +0800119#else
120static inline int power_domain_free(struct power_domain *power_domain)
121{
122 return -ENOSYS;
123}
124#endif
Stephen Warren92c67fa2016-07-13 13:45:31 -0600125
126/**
127 * power_domain_on - Enable power to a power domain.
128 *
129 * @power_domain: A power domain struct that was previously successfully
130 * requested by power_domain_get().
131 * @return 0 if OK, or a negative error code.
132 */
Peng Fan57965702018-07-27 10:20:36 +0800133#if CONFIG_IS_ENABLED(POWER_DOMAIN)
Stephen Warren92c67fa2016-07-13 13:45:31 -0600134int power_domain_on(struct power_domain *power_domain);
Peng Fan57965702018-07-27 10:20:36 +0800135#else
136static inline int power_domain_on(struct power_domain *power_domain)
137{
138 return -ENOSYS;
139}
140#endif
Stephen Warren92c67fa2016-07-13 13:45:31 -0600141
142/**
Anatolij Gustschine601f542019-07-10 10:03:13 +0200143 * power_domain_off - Disable power to a power domain.
Stephen Warren92c67fa2016-07-13 13:45:31 -0600144 *
145 * @power_domain: A power domain struct that was previously successfully
146 * requested by power_domain_get().
147 * @return 0 if OK, or a negative error code.
148 */
Peng Fan57965702018-07-27 10:20:36 +0800149#if CONFIG_IS_ENABLED(POWER_DOMAIN)
Stephen Warren92c67fa2016-07-13 13:45:31 -0600150int power_domain_off(struct power_domain *power_domain);
Peng Fan57965702018-07-27 10:20:36 +0800151#else
152static inline int power_domain_off(struct power_domain *power_domain)
153{
154 return -ENOSYS;
155}
156#endif
Stephen Warren92c67fa2016-07-13 13:45:31 -0600157
158#endif