2 * Copyright (c) 2005-2007 Nate Lawson (SDG)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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32 #include <sys/eventhandler.h>
38 #define CPU_IVAR_PCPU 1
39 #define CPU_IVAR_NOMINAL_MHZ 2
40 #define CPU_IVAR_CPUID_SIZE 3
41 #define CPU_IVAR_CPUID 4
43 static __inline struct pcpu *cpu_get_pcpu(device_t dev)
46 BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
47 return ((struct pcpu *)v);
50 static __inline int32_t cpu_get_nominal_mhz(device_t dev)
53 if (BUS_READ_IVAR(device_get_parent(dev), dev,
54 CPU_IVAR_NOMINAL_MHZ, &v) != 0)
59 static __inline const uint32_t *cpu_get_cpuid(device_t dev, size_t *count)
62 if (BUS_READ_IVAR(device_get_parent(dev), dev,
63 CPU_IVAR_CPUID_SIZE, &v) != 0)
67 if (BUS_READ_IVAR(device_get_parent(dev), dev,
68 CPU_IVAR_CPUID, &v) != 0)
70 return ((const uint32_t *)v);
74 * CPU frequency control interface.
77 /* Each driver's CPU frequency setting is exported in this format. */
79 int freq; /* CPU clock in Mhz or 100ths of a percent. */
80 int volts; /* Voltage in mV. */
81 int power; /* Power consumed in mW. */
82 int lat; /* Transition latency in us. */
83 device_t dev; /* Driver providing this setting. */
84 int spec[4];/* Driver-specific storage for non-standard info. */
87 /* Maximum number of settings a given driver can have. */
88 #define MAX_SETTINGS 24
90 /* A combination of settings is a level. */
92 struct cf_setting total_set;
93 struct cf_setting abs_set;
94 struct cf_setting rel_set[MAX_SETTINGS];
96 TAILQ_ENTRY(cf_level) link;
99 TAILQ_HEAD(cf_level_lst, cf_level);
101 /* Drivers should set all unknown values to this. */
102 #define CPUFREQ_VAL_UNKNOWN (-1)
105 * Every driver offers a type of CPU control. Absolute levels are mutually
106 * exclusive while relative levels modify the current absolute level. There
107 * may be multiple absolute and relative drivers available on a given
110 * For example, consider a system with two absolute drivers that provide
111 * frequency settings of 100, 200 and 300, 400 and a relative driver that
112 * provides settings of 50%, 100%. The cpufreq core would export frequency
113 * levels of 50, 100, 150, 200, 300, 400.
115 * The "info only" flag signifies that settings returned by
116 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
117 * are only informational. This is for some drivers that can return
118 * information about settings but rely on another machine-dependent driver
119 * for actually performing the frequency transition (e.g., ACPI performance
120 * states of type "functional fixed hardware.")
122 #define CPUFREQ_TYPE_MASK 0xffff
123 #define CPUFREQ_TYPE_RELATIVE (1<<0)
124 #define CPUFREQ_TYPE_ABSOLUTE (1<<1)
125 #define CPUFREQ_FLAG_INFO_ONLY (1<<16)
128 * When setting a level, the caller indicates the priority of this request.
129 * Priorities determine, among other things, whether a level can be
130 * overridden by other callers. For example, if the user sets a level but
131 * the system thermal driver needs to override it for emergency cooling,
132 * the driver would use a higher priority. Once the event has passed, the
133 * driver would call cpufreq to resume any previous level.
135 #define CPUFREQ_PRIO_HIGHEST 1000000
136 #define CPUFREQ_PRIO_KERN 1000
137 #define CPUFREQ_PRIO_USER 100
138 #define CPUFREQ_PRIO_LOWEST 0
141 * Register and unregister a driver with the cpufreq core. Once a driver
142 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
143 * and CPUFREQ_SET methods. It must also unregister before returning from
144 * its DEVICE_DETACH method.
146 int cpufreq_register(device_t dev);
147 int cpufreq_unregister(device_t dev);
150 * Notify the cpufreq core that the number of or values for settings have
153 int cpufreq_settings_changed(device_t dev);
156 * Eventhandlers that are called before and after a change in frequency.
157 * The new level and the result of the change (0 is success) is passed in.
158 * If the driver wishes to revoke the change from cpufreq_pre_change, it
159 * stores a non-zero error code in the result parameter and the change will
160 * not be made. If the post-change eventhandler gets a non-zero result,
161 * no change was made and the previous level remains in effect. If a change
162 * is revoked, the post-change eventhandler is still called with the error
163 * value supplied by the revoking driver. This gives listeners who cached
164 * some data in preparation for a level change a chance to clean up.
166 typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
167 typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
168 EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
169 EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
172 * Eventhandler called when the available list of levels changed.
173 * The unit number of the device (i.e. "cpufreq0") whose levels changed
174 * is provided so the listener can retrieve the new list of levels.
176 typedef void (*cpufreq_levels_notify_fn)(void *, int);
177 EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
179 /* Allow values to be +/- a bit since sometimes we have to estimate. */
180 #define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
183 * Machine-dependent functions.
186 /* Estimate the current clock rate for the given CPU id. */
187 int cpu_est_clockrate(int cpu_id, uint64_t *rate);
189 #endif /* !_SYS_CPU_H_ */