xref: /linux-6.15/include/linux/pm.h (revision a17627ef)
1 /*
2  *  pm.h - Power management interface
3  *
4  *  Copyright (C) 2000 Andrew Henroid
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 
21 #ifndef _LINUX_PM_H
22 #define _LINUX_PM_H
23 
24 #ifdef __KERNEL__
25 
26 #include <linux/list.h>
27 #include <asm/atomic.h>
28 
29 /*
30  * Power management requests... these are passed to pm_send_all() and friends.
31  *
32  * these functions are old and deprecated, see below.
33  */
34 typedef int __bitwise pm_request_t;
35 
36 #define PM_SUSPEND	((__force pm_request_t) 1)	/* enter D1-D3 */
37 #define PM_RESUME	((__force pm_request_t) 2)	/* enter D0 */
38 
39 
40 /*
41  * Device types... these are passed to pm_register
42  */
43 typedef int __bitwise pm_dev_t;
44 
45 #define PM_UNKNOWN_DEV	((__force pm_dev_t) 0)	/* generic */
46 #define PM_SYS_DEV	((__force pm_dev_t) 1)	/* system device (fan, KB controller, ...) */
47 #define PM_PCI_DEV	((__force pm_dev_t) 2)	/* PCI device */
48 #define PM_USB_DEV	((__force pm_dev_t) 3)	/* USB device */
49 #define PM_SCSI_DEV	((__force pm_dev_t) 4)	/* SCSI device */
50 #define PM_ISA_DEV	((__force pm_dev_t) 5)	/* ISA device */
51 #define	PM_MTD_DEV	((__force pm_dev_t) 6)	/* Memory Technology Device */
52 
53 /*
54  * System device hardware ID (PnP) values
55  */
56 enum
57 {
58 	PM_SYS_UNKNOWN = 0x00000000, /* generic */
59 	PM_SYS_KBC =	 0x41d00303, /* keyboard controller */
60 	PM_SYS_COM =	 0x41d00500, /* serial port */
61 	PM_SYS_IRDA =	 0x41d00510, /* IRDA controller */
62 	PM_SYS_FDC =	 0x41d00700, /* floppy controller */
63 	PM_SYS_VGA =	 0x41d00900, /* VGA controller */
64 	PM_SYS_PCMCIA =	 0x41d00e00, /* PCMCIA controller */
65 };
66 
67 /*
68  * Device identifier
69  */
70 #define PM_PCI_ID(dev) ((dev)->bus->number << 16 | (dev)->devfn)
71 
72 /*
73  * Request handler callback
74  */
75 struct pm_dev;
76 
77 typedef int (*pm_callback)(struct pm_dev *dev, pm_request_t rqst, void *data);
78 
79 /*
80  * Dynamic device information
81  */
82 struct pm_dev
83 {
84 	pm_dev_t	 type;
85 	unsigned long	 id;
86 	pm_callback	 callback;
87 	void		*data;
88 
89 	unsigned long	 flags;
90 	unsigned long	 state;
91 	unsigned long	 prev_state;
92 
93 	struct list_head entry;
94 };
95 
96 /* Functions above this comment are list-based old-style power
97  * managment. Please avoid using them.  */
98 
99 /*
100  * Callbacks for platform drivers to implement.
101  */
102 extern void (*pm_idle)(void);
103 extern void (*pm_power_off)(void);
104 
105 typedef int __bitwise suspend_state_t;
106 
107 #define PM_SUSPEND_ON		((__force suspend_state_t) 0)
108 #define PM_SUSPEND_STANDBY	((__force suspend_state_t) 1)
109 #define PM_SUSPEND_MEM		((__force suspend_state_t) 3)
110 #define PM_SUSPEND_MAX		((__force suspend_state_t) 4)
111 
112 /**
113  * struct pm_ops - Callbacks for managing platform dependent suspend states.
114  * @valid: Callback to determine whether the given state can be entered.
115  *	Valid states are advertised in /sys/power/state but can still
116  *	be rejected by prepare or enter if the conditions aren't right.
117  *	There is a %pm_valid_only_mem function available that can be assigned
118  *	to this if you only implement mem sleep.
119  *
120  * @prepare: Prepare the platform for the given suspend state. Can return a
121  *	negative error code if necessary.
122  *
123  * @enter: Enter the given suspend state, must be assigned. Can return a
124  *	negative error code if necessary.
125  *
126  * @finish: Called when the system has left the given state and all devices
127  *	are resumed. The return value is ignored.
128  */
129 struct pm_ops {
130 	int (*valid)(suspend_state_t state);
131 	int (*prepare)(suspend_state_t state);
132 	int (*enter)(suspend_state_t state);
133 	int (*finish)(suspend_state_t state);
134 };
135 
136 /**
137  * pm_set_ops - set platform dependent power management ops
138  * @pm_ops: The new power management operations to set.
139  */
140 extern void pm_set_ops(struct pm_ops *pm_ops);
141 extern struct pm_ops *pm_ops;
142 extern int pm_suspend(suspend_state_t state);
143 
144 extern int pm_valid_only_mem(suspend_state_t state);
145 
146 /**
147  * arch_suspend_disable_irqs - disable IRQs for suspend
148  *
149  * Disables IRQs (in the default case). This is a weak symbol in the common
150  * code and thus allows architectures to override it if more needs to be
151  * done. Not called for suspend to disk.
152  */
153 extern void arch_suspend_disable_irqs(void);
154 
155 /**
156  * arch_suspend_enable_irqs - enable IRQs after suspend
157  *
158  * Enables IRQs (in the default case). This is a weak symbol in the common
159  * code and thus allows architectures to override it if more needs to be
160  * done. Not called for suspend to disk.
161  */
162 extern void arch_suspend_enable_irqs(void);
163 
164 /*
165  * Device power management
166  */
167 
168 struct device;
169 
170 typedef struct pm_message {
171 	int event;
172 } pm_message_t;
173 
174 /*
175  * Several driver power state transitions are externally visible, affecting
176  * the state of pending I/O queues and (for drivers that touch hardware)
177  * interrupts, wakeups, DMA, and other hardware state.  There may also be
178  * internal transitions to various low power modes, which are transparent
179  * to the rest of the driver stack (such as a driver that's ON gating off
180  * clocks which are not in active use).
181  *
182  * One transition is triggered by resume(), after a suspend() call; the
183  * message is implicit:
184  *
185  * ON		Driver starts working again, responding to hardware events
186  * 		and software requests.  The hardware may have gone through
187  * 		a power-off reset, or it may have maintained state from the
188  * 		previous suspend() which the driver will rely on while
189  * 		resuming.  On most platforms, there are no restrictions on
190  * 		availability of resources like clocks during resume().
191  *
192  * Other transitions are triggered by messages sent using suspend().  All
193  * these transitions quiesce the driver, so that I/O queues are inactive.
194  * That commonly entails turning off IRQs and DMA; there may be rules
195  * about how to quiesce that are specific to the bus or the device's type.
196  * (For example, network drivers mark the link state.)  Other details may
197  * differ according to the message:
198  *
199  * SUSPEND	Quiesce, enter a low power device state appropriate for
200  * 		the upcoming system state (such as PCI_D3hot), and enable
201  * 		wakeup events as appropriate.
202  *
203  * FREEZE	Quiesce operations so that a consistent image can be saved;
204  * 		but do NOT otherwise enter a low power device state, and do
205  * 		NOT emit system wakeup events.
206  *
207  * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
208  * 		the system from a snapshot taken after an earlier FREEZE.
209  * 		Some drivers will need to reset their hardware state instead
210  * 		of preserving it, to ensure that it's never mistaken for the
211  * 		state which that earlier snapshot had set up.
212  *
213  * A minimally power-aware driver treats all messages as SUSPEND, fully
214  * reinitializes its device during resume() -- whether or not it was reset
215  * during the suspend/resume cycle -- and can't issue wakeup events.
216  *
217  * More power-aware drivers may also use low power states at runtime as
218  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
219  * be able to use wakeup events to exit from runtime low-power states,
220  * or from system low-power states such as standby or suspend-to-RAM.
221  */
222 
223 #define PM_EVENT_ON 0
224 #define PM_EVENT_FREEZE 1
225 #define PM_EVENT_SUSPEND 2
226 #define PM_EVENT_PRETHAW 3
227 
228 #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
229 #define PMSG_PRETHAW	((struct pm_message){ .event = PM_EVENT_PRETHAW, })
230 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
231 #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
232 
233 struct dev_pm_info {
234 	pm_message_t		power_state;
235 	unsigned		can_wakeup:1;
236 #ifdef	CONFIG_PM
237 	unsigned		should_wakeup:1;
238 	pm_message_t		prev_state;
239 	void			* saved_state;
240 	struct device		* pm_parent;
241 	struct list_head	entry;
242 #endif
243 };
244 
245 extern void device_pm_set_parent(struct device * dev, struct device * parent);
246 
247 extern int device_power_down(pm_message_t state);
248 extern void device_power_up(void);
249 extern void device_resume(void);
250 
251 #ifdef CONFIG_PM
252 extern int device_suspend(pm_message_t state);
253 extern int device_prepare_suspend(pm_message_t state);
254 
255 #define device_set_wakeup_enable(dev,val) \
256 	((dev)->power.should_wakeup = !!(val))
257 #define device_may_wakeup(dev) \
258 	(device_can_wakeup(dev) && (dev)->power.should_wakeup)
259 
260 extern int dpm_runtime_suspend(struct device *, pm_message_t);
261 extern void dpm_runtime_resume(struct device *);
262 extern void __suspend_report_result(const char *function, void *fn, int ret);
263 
264 #define suspend_report_result(fn, ret)					\
265 	do {								\
266 		__suspend_report_result(__FUNCTION__, fn, ret);		\
267 	} while (0)
268 
269 /*
270  * Platform hook to activate device wakeup capability, if that's not already
271  * handled by enable_irq_wake() etc.
272  * Returns zero on success, else negative errno
273  */
274 extern int (*platform_enable_wakeup)(struct device *dev, int is_on);
275 
276 static inline int call_platform_enable_wakeup(struct device *dev, int is_on)
277 {
278 	if (platform_enable_wakeup)
279 		return (*platform_enable_wakeup)(dev, is_on);
280 	return 0;
281 }
282 
283 #else /* !CONFIG_PM */
284 
285 static inline int device_suspend(pm_message_t state)
286 {
287 	return 0;
288 }
289 
290 #define device_set_wakeup_enable(dev,val)	do{}while(0)
291 #define device_may_wakeup(dev)			(0)
292 
293 static inline int dpm_runtime_suspend(struct device * dev, pm_message_t state)
294 {
295 	return 0;
296 }
297 
298 static inline void dpm_runtime_resume(struct device * dev)
299 {
300 }
301 
302 #define suspend_report_result(fn, ret) do { } while (0)
303 
304 static inline int call_platform_enable_wakeup(struct device *dev, int is_on)
305 {
306 	return 0;
307 }
308 
309 #endif
310 
311 /* changes to device_may_wakeup take effect on the next pm state change.
312  * by default, devices should wakeup if they can.
313  */
314 #define device_can_wakeup(dev) \
315 	((dev)->power.can_wakeup)
316 #define device_init_wakeup(dev,val) \
317 	do { \
318 		device_can_wakeup(dev) = !!(val); \
319 		device_set_wakeup_enable(dev,val); \
320 	} while(0)
321 
322 #endif /* __KERNEL__ */
323 
324 #endif /* _LINUX_PM_H */
325