aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/plat-omap/include/plat/omap-pm.h
blob: 0840df813f4f15f4e5b0ecc1cfcd0b53269f0549 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
/*
 * omap-pm.h - OMAP power management interface
 *
 * Copyright (C) 2008-2010 Texas Instruments, Inc.
 * Copyright (C) 2008-2010 Nokia Corporation
 * Paul Walmsley
 *
 * Interface developed by (in alphabetical order): Karthik Dasu, Jouni
 * Högander, Tony Lindgren, Rajendra Nayak, Sakari Poussa,
 * Veeramanikandan Raju, Anand Sawant, Igor Stoppa, Paul Walmsley,
 * Richard Woodruff
 */

#ifndef ASM_ARM_ARCH_OMAP_OMAP_PM_H
#define ASM_ARM_ARCH_OMAP_OMAP_PM_H

#include <linux/device.h>
#include <linux/cpufreq.h>
#include <linux/clk.h>
#include <linux/opp.h>

/*
 * agent_id values for use with omap_pm_set_min_bus_tput():
 *
 * OCP_INITIATOR_AGENT is only valid for devices that can act as
 * initiators -- it represents the device's L3 interconnect
 * connection.  OCP_TARGET_AGENT represents the device's L4
 * interconnect connection.
 */
#define OCP_TARGET_AGENT		1
#define OCP_INITIATOR_AGENT		2

/**
 * omap_pm_if_early_init - OMAP PM init code called before clock fw init
 * @mpu_opp_table: array ptr to struct omap_opp for MPU
 * @dsp_opp_table: array ptr to struct omap_opp for DSP
 * @l3_opp_table : array ptr to struct omap_opp for CORE
 *
 * Initialize anything that must be configured before the clock
 * framework starts.  The "_if_" is to avoid name collisions with the
 * PM idle-loop code.
 */
int __init omap_pm_if_early_init(void);

/**
 * omap_pm_if_init - OMAP PM init code called after clock fw init
 *
 * The main initialization code.  OPP tables are passed in here.  The
 * "_if_" is to avoid name collisions with the PM idle-loop code.
 */
int __init omap_pm_if_init(void);

/**
 * omap_pm_if_exit - OMAP PM exit code
 *
 * Exit code; currently unused.  The "_if_" is to avoid name
 * collisions with the PM idle-loop code.
 */
void omap_pm_if_exit(void);

/*
 * Device-driver-originated constraints (via board-*.c files, platform_data)
 */


/**
 * omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency
 * @dev: struct device * requesting the constraint
 * @t: maximum MPU wakeup latency in microseconds
 *
 * Request that the maximum interrupt latency for the MPU to be no
 * greater than @t microseconds. "Interrupt latency" in this case is
 * defined as the elapsed time from the occurrence of a hardware or
 * timer interrupt to the time when the device driver's interrupt
 * service routine has been entered by the MPU.
 *
 * It is intended that underlying PM code will use this information to
 * determine what power state to put the MPU powerdomain into, and
 * possibly the CORE powerdomain as well, since interrupt handling
 * code currently runs from SDRAM.  Advanced PM or board*.c code may
 * also configure interrupt controller priorities, OCP bus priorities,
 * CPU speed(s), etc.
 *
 * This function will not affect device wakeup latency, e.g., time
 * elapsed from when a device driver enables a hardware device with
 * clk_enable(), to when the device is ready for register access or
 * other use.  To control this device wakeup latency, use
 * omap_pm_set_max_dev_wakeup_lat()
 *
 * Multiple calls to omap_pm_set_max_mpu_wakeup_lat() will replace the
 * previous t value.  To remove the latency target for the MPU, call
 * with t = -1.
 *
 * XXX This constraint will be deprecated soon in favor of the more
 * general omap_pm_set_max_dev_wakeup_lat()
 *
 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 * is not satisfiable, or 0 upon success.
 */
int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t);


/**
 * omap_pm_set_min_bus_tput - set minimum bus throughput needed by device
 * @dev: struct device * requesting the constraint
 * @tbus_id: interconnect to operate on (OCP_{INITIATOR,TARGET}_AGENT)
 * @r: minimum throughput (in KiB/s)
 *
 * Request that the minimum data throughput on the OCP interconnect
 * attached to device @dev interconnect agent @tbus_id be no less
 * than @r KiB/s.
 *
 * It is expected that the OMAP PM or bus code will use this
 * information to set the interconnect clock to run at the lowest
 * possible speed that satisfies all current system users.  The PM or
 * bus code will adjust the estimate based on its model of the bus, so
 * device driver authors should attempt to specify an accurate
 * quantity for their device use case, and let the PM or bus code
 * overestimate the numbers as necessary to handle request/response
 * latency, other competing users on the system, etc.  On OMAP2/3, if
 * a driver requests a minimum L4 interconnect speed constraint, the
 * code will also need to add an minimum L3 interconnect speed
 * constraint,
 *
 * Multiple calls to omap_pm_set_min_bus_tput() will replace the
 * previous rate value for this device.  To remove the interconnect
 * throughput restriction for this device, call with r = 0.
 *
 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 * is not satisfiable, or 0 upon success.
 */
int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r);


/**
 * omap_pm_set_max_dev_wakeup_lat - set the maximum device enable latency
 * @req_dev: struct device * requesting the constraint, or NULL if none
 * @dev: struct device * to set the constraint one
 * @t: maximum device wakeup latency in microseconds
 *
 * Request that the maximum amount of time necessary for a device @dev
 * to become accessible after its clocks are enabled should be no
 * greater than @t microseconds.  Specifically, this represents the
 * time from when a device driver enables device clocks with
 * clk_enable(), to when the register reads and writes on the device
 * will succeed.  This function should be called before clk_disable()
 * is called, since the power state transition decision may be made
 * during clk_disable().
 *
 * It is intended that underlying PM code will use this information to
 * determine what power state to put the powerdomain enclosing this
 * device into.
 *
 * Multiple calls to omap_pm_set_max_dev_wakeup_lat() will replace the
 * previous wakeup latency values for this device.  To remove the
 * wakeup latency restriction for this device, call with t = -1.
 *
 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 * is not satisfiable, or 0 upon success.
 */
int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
				   long t);


/**
 * omap_pm_set_max_sdma_lat - set the maximum system DMA transfer start latency
 * @dev: struct device *
 * @t: maximum DMA transfer start latency in microseconds
 *
 * Request that the maximum system DMA transfer start latency for this
 * device 'dev' should be no greater than 't' microseconds.  "DMA
 * transfer start latency" here is defined as the elapsed time from
 * when a device (e.g., McBSP) requests that a system DMA transfer
 * start or continue, to the time at which data starts to flow into
 * that device from the system DMA controller.
 *
 * It is intended that underlying PM code will use this information to
 * determine what power state to put the CORE powerdomain into.
 *
 * Since system DMA transfers may not involve the MPU, this function
 * will not affect MPU wakeup latency.  Use set_max_cpu_lat() to do
 * so.  Similarly, this function will not affect device wakeup latency
 * -- use set_max_dev_wakeup_lat() to affect that.
 *
 * Multiple calls to set_max_sdma_lat() will replace the previous t
 * value for this device.  To remove the maximum DMA latency for this
 * device, call with t = -1.
 *
 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 * is not satisfiable, or 0 upon success.
 */
int omap_pm_set_max_sdma_lat(struct device *dev, long t);


/**
 * omap_pm_set_min_clk_rate - set minimum clock rate requested by @dev
 * @dev: struct device * requesting the constraint
 * @clk: struct clk * to set the minimum rate constraint on
 * @r: minimum rate in Hz
 *
 * Request that the minimum clock rate on the device @dev's clk @clk
 * be no less than @r Hz.
 *
 * It is expected that the OMAP PM code will use this information to
 * find an OPP or clock setting that will satisfy this clock rate
 * constraint, along with any other applicable system constraints on
 * the clock rate or corresponding voltage, etc.
 *
 * omap_pm_set_min_clk_rate() differs from the clock code's
 * clk_set_rate() in that it considers other constraints before taking
 * any hardware action, and may change a system OPP rather than just a
 * clock rate.  clk_set_rate() is intended to be a low-level
 * interface.
 *
 * omap_pm_set_min_clk_rate() is easily open to abuse.  A better API
 * would be something like "omap_pm_set_min_dev_performance()";
 * however, there is no easily-generalizable concept of performance
 * that applies to all devices.  Only a device (and possibly the
 * device subsystem) has both the subsystem-specific knowledge, and
 * the hardware IP block-specific knowledge, to translate a constraint
 * on "touchscreen sampling accuracy" or "number of pixels or polygons
 * rendered per second" to a clock rate.  This translation can be
 * dependent on the hardware IP block's revision, or firmware version,
 * and the driver is the only code on the system that has this
 * information and can know how to translate that into a clock rate.
 *
 * The intended use-case for this function is for userspace or other
 * kernel code to communicate a particular performance requirement to
 * a subsystem; then for the subsystem to communicate that requirement
 * to something that is meaningful to the device driver; then for the
 * device driver to convert that requirement to a clock rate, and to
 * then call omap_pm_set_min_clk_rate().
 *
 * Users of this function (such as device drivers) should not simply
 * call this function with some high clock rate to ensure "high
 * performance."  Rather, the device driver should take a performance
 * constraint from its subsystem, such as "render at least X polygons
 * per second," and use some formula or table to convert that into a
 * clock rate constraint given the hardware type and hardware
 * revision.  Device drivers or subsystems should not assume that they
 * know how to make a power/performance tradeoff - some device use
 * cases may tolerate a lower-fidelity device function for lower power
 * consumption; others may demand a higher-fidelity device function,
 * no matter what the power consumption.
 *
 * Multiple calls to omap_pm_set_min_clk_rate() will replace the
 * previous rate value for the device @dev.  To remove the minimum clock
 * rate constraint for the device, call with r = 0.
 *
 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 * is not satisfiable, or 0 upon success.
 */
int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r);

/*
 * DSP Bridge-specific constraints
 */

/**
 * omap_pm_dsp_get_opp_table - get OPP->DSP clock frequency table
 *
 * Intended for use by DSPBridge.  Returns an array of OPP->DSP clock
 * frequency entries.  The final item in the array should have .rate =
 * .opp_id = 0.
 */
const struct omap_opp *omap_pm_dsp_get_opp_table(void);

/**
 * omap_pm_dsp_set_min_opp - receive desired OPP target ID from DSP Bridge
 * @opp_id: target DSP OPP ID
 *
 * Set a minimum OPP ID for the DSP.  This is intended to be called
 * only from the DSP Bridge MPU-side driver.  Unfortunately, the only
 * information that code receives from the DSP/BIOS load estimator is the
 * target OPP ID; hence, this interface.  No return value.
 */
void omap_pm_dsp_set_min_opp(u8 opp_id);

/**
 * omap_pm_dsp_get_opp - report the current DSP OPP ID
 *
 * Report the current OPP for the DSP.  Since on OMAP3, the DSP and
 * MPU share a single voltage domain, the OPP ID returned back may
 * represent a higher DSP speed than the OPP requested via
 * omap_pm_dsp_set_min_opp().
 *
 * Returns the current VDD1 OPP ID, or 0 upon error.
 */
u8 omap_pm_dsp_get_opp(void);


/*
 * CPUFreq-originated constraint
 *
 * In the future, this should be handled by custom OPP clocktype
 * functions.
 */

/**
 * omap_pm_cpu_get_freq_table - return a cpufreq_frequency_table array ptr
 *
 * Provide a frequency table usable by CPUFreq for the current chip/board.
 * Returns a pointer to a struct cpufreq_frequency_table array or NULL
 * upon error.
 */
struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void);

/**
 * omap_pm_cpu_set_freq - set the current minimum MPU frequency
 * @f: MPU frequency in Hz
 *
 * Set the current minimum CPU frequency.  The actual CPU frequency
 * used could end up higher if the DSP requested a higher OPP.
 * Intended to be called by plat-omap/cpu_omap.c:omap_target().  No
 * return value.
 */
void omap_pm_cpu_set_freq(unsigned long f);

/**
 * omap_pm_cpu_get_freq - report the current CPU frequency
 *
 * Returns the current MPU frequency, or 0 upon error.
 */
unsigned long omap_pm_cpu_get_freq(void);


/*
 * Device context loss tracking
 */

/**
 * omap_pm_get_dev_context_loss_count - return count of times dev has lost ctx
 * @dev: struct device *
 *
 * This function returns the number of times that the device @dev has
 * lost its internal context.  This generally occurs on a powerdomain
 * transition to OFF.  Drivers use this as an optimization to avoid restoring
 * context if the device hasn't lost it.  To use, drivers should initially
 * call this in their context save functions and store the result.  Early in
 * the driver's context restore function, the driver should call this function
 * again, and compare the result to the stored counter.  If they differ, the
 * driver must restore device context.   If the number of context losses
 * exceeds the maximum positive integer, the function will wrap to 0 and
 * continue counting.  Returns the number of context losses for this device,
 * or zero upon error.
 */
u32 omap_pm_get_dev_context_loss_count(struct device *dev);

void omap_pm_enable_off_mode(void);
void omap_pm_disable_off_mode(void);

#endif