2 * omap-pm.h - OMAP power management interface
4 * Copyright (C) 2008-2010 Texas Instruments, Inc.
5 * Copyright (C) 2008-2010 Nokia Corporation
8 * Interface developed by (in alphabetical order): Karthik Dasu, Jouni
9 * Högander, Tony Lindgren, Rajendra Nayak, Sakari Poussa,
10 * Veeramanikandan Raju, Anand Sawant, Igor Stoppa, Paul Walmsley,
14 #ifndef ASM_ARM_ARCH_OMAP_OMAP_PM_H
15 #define ASM_ARM_ARCH_OMAP_OMAP_PM_H
17 #include <linux/device.h>
18 #include <linux/cpufreq.h>
19 #include <linux/clk.h>
20 #include <linux/opp.h>
23 * agent_id values for use with omap_pm_set_min_bus_tput():
25 * OCP_INITIATOR_AGENT is only valid for devices that can act as
26 * initiators -- it represents the device's L3 interconnect
27 * connection. OCP_TARGET_AGENT represents the device's L4
28 * interconnect connection.
30 #define OCP_TARGET_AGENT 1
31 #define OCP_INITIATOR_AGENT 2
34 * omap_pm_if_early_init - OMAP PM init code called before clock fw init
35 * @mpu_opp_table: array ptr to struct omap_opp for MPU
36 * @dsp_opp_table: array ptr to struct omap_opp for DSP
37 * @l3_opp_table : array ptr to struct omap_opp for CORE
39 * Initialize anything that must be configured before the clock
40 * framework starts. The "_if_" is to avoid name collisions with the
43 int __init
omap_pm_if_early_init(void);
46 * omap_pm_if_init - OMAP PM init code called after clock fw init
48 * The main initialization code. OPP tables are passed in here. The
49 * "_if_" is to avoid name collisions with the PM idle-loop code.
51 int __init
omap_pm_if_init(void);
54 * omap_pm_if_exit - OMAP PM exit code
56 * Exit code; currently unused. The "_if_" is to avoid name
57 * collisions with the PM idle-loop code.
59 void omap_pm_if_exit(void);
62 * Device-driver-originated constraints (via board-*.c files, platform_data)
67 * omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency
68 * @dev: struct device * requesting the constraint
69 * @t: maximum MPU wakeup latency in microseconds
71 * Request that the maximum interrupt latency for the MPU to be no
72 * greater than @t microseconds. "Interrupt latency" in this case is
73 * defined as the elapsed time from the occurrence of a hardware or
74 * timer interrupt to the time when the device driver's interrupt
75 * service routine has been entered by the MPU.
77 * It is intended that underlying PM code will use this information to
78 * determine what power state to put the MPU powerdomain into, and
79 * possibly the CORE powerdomain as well, since interrupt handling
80 * code currently runs from SDRAM. Advanced PM or board*.c code may
81 * also configure interrupt controller priorities, OCP bus priorities,
84 * This function will not affect device wakeup latency, e.g., time
85 * elapsed from when a device driver enables a hardware device with
86 * clk_enable(), to when the device is ready for register access or
87 * other use. To control this device wakeup latency, use
88 * omap_pm_set_max_dev_wakeup_lat()
90 * Multiple calls to omap_pm_set_max_mpu_wakeup_lat() will replace the
91 * previous t value. To remove the latency target for the MPU, call
94 * XXX This constraint will be deprecated soon in favor of the more
95 * general omap_pm_set_max_dev_wakeup_lat()
97 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
98 * is not satisfiable, or 0 upon success.
100 int omap_pm_set_max_mpu_wakeup_lat(struct device
*dev
, long t
);
104 * omap_pm_set_min_bus_tput - set minimum bus throughput needed by device
105 * @dev: struct device * requesting the constraint
106 * @tbus_id: interconnect to operate on (OCP_{INITIATOR,TARGET}_AGENT)
107 * @r: minimum throughput (in KiB/s)
109 * Request that the minimum data throughput on the OCP interconnect
110 * attached to device @dev interconnect agent @tbus_id be no less
113 * It is expected that the OMAP PM or bus code will use this
114 * information to set the interconnect clock to run at the lowest
115 * possible speed that satisfies all current system users. The PM or
116 * bus code will adjust the estimate based on its model of the bus, so
117 * device driver authors should attempt to specify an accurate
118 * quantity for their device use case, and let the PM or bus code
119 * overestimate the numbers as necessary to handle request/response
120 * latency, other competing users on the system, etc. On OMAP2/3, if
121 * a driver requests a minimum L4 interconnect speed constraint, the
122 * code will also need to add an minimum L3 interconnect speed
125 * Multiple calls to omap_pm_set_min_bus_tput() will replace the
126 * previous rate value for this device. To remove the interconnect
127 * throughput restriction for this device, call with r = 0.
129 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
130 * is not satisfiable, or 0 upon success.
132 int omap_pm_set_min_bus_tput(struct device
*dev
, u8 agent_id
, unsigned long r
);
136 * omap_pm_set_max_dev_wakeup_lat - set the maximum device enable latency
137 * @req_dev: struct device * requesting the constraint, or NULL if none
138 * @dev: struct device * to set the constraint one
139 * @t: maximum device wakeup latency in microseconds
141 * Request that the maximum amount of time necessary for a device @dev
142 * to become accessible after its clocks are enabled should be no
143 * greater than @t microseconds. Specifically, this represents the
144 * time from when a device driver enables device clocks with
145 * clk_enable(), to when the register reads and writes on the device
146 * will succeed. This function should be called before clk_disable()
147 * is called, since the power state transition decision may be made
148 * during clk_disable().
150 * It is intended that underlying PM code will use this information to
151 * determine what power state to put the powerdomain enclosing this
154 * Multiple calls to omap_pm_set_max_dev_wakeup_lat() will replace the
155 * previous wakeup latency values for this device. To remove the
156 * wakeup latency restriction for this device, call with t = -1.
158 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
159 * is not satisfiable, or 0 upon success.
161 int omap_pm_set_max_dev_wakeup_lat(struct device
*req_dev
, struct device
*dev
,
166 * omap_pm_set_max_sdma_lat - set the maximum system DMA transfer start latency
167 * @dev: struct device *
168 * @t: maximum DMA transfer start latency in microseconds
170 * Request that the maximum system DMA transfer start latency for this
171 * device 'dev' should be no greater than 't' microseconds. "DMA
172 * transfer start latency" here is defined as the elapsed time from
173 * when a device (e.g., McBSP) requests that a system DMA transfer
174 * start or continue, to the time at which data starts to flow into
175 * that device from the system DMA controller.
177 * It is intended that underlying PM code will use this information to
178 * determine what power state to put the CORE powerdomain into.
180 * Since system DMA transfers may not involve the MPU, this function
181 * will not affect MPU wakeup latency. Use set_max_cpu_lat() to do
182 * so. Similarly, this function will not affect device wakeup latency
183 * -- use set_max_dev_wakeup_lat() to affect that.
185 * Multiple calls to set_max_sdma_lat() will replace the previous t
186 * value for this device. To remove the maximum DMA latency for this
187 * device, call with t = -1.
189 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
190 * is not satisfiable, or 0 upon success.
192 int omap_pm_set_max_sdma_lat(struct device
*dev
, long t
);
196 * omap_pm_set_min_clk_rate - set minimum clock rate requested by @dev
197 * @dev: struct device * requesting the constraint
198 * @clk: struct clk * to set the minimum rate constraint on
199 * @r: minimum rate in Hz
201 * Request that the minimum clock rate on the device @dev's clk @clk
202 * be no less than @r Hz.
204 * It is expected that the OMAP PM code will use this information to
205 * find an OPP or clock setting that will satisfy this clock rate
206 * constraint, along with any other applicable system constraints on
207 * the clock rate or corresponding voltage, etc.
209 * omap_pm_set_min_clk_rate() differs from the clock code's
210 * clk_set_rate() in that it considers other constraints before taking
211 * any hardware action, and may change a system OPP rather than just a
212 * clock rate. clk_set_rate() is intended to be a low-level
215 * omap_pm_set_min_clk_rate() is easily open to abuse. A better API
216 * would be something like "omap_pm_set_min_dev_performance()";
217 * however, there is no easily-generalizable concept of performance
218 * that applies to all devices. Only a device (and possibly the
219 * device subsystem) has both the subsystem-specific knowledge, and
220 * the hardware IP block-specific knowledge, to translate a constraint
221 * on "touchscreen sampling accuracy" or "number of pixels or polygons
222 * rendered per second" to a clock rate. This translation can be
223 * dependent on the hardware IP block's revision, or firmware version,
224 * and the driver is the only code on the system that has this
225 * information and can know how to translate that into a clock rate.
227 * The intended use-case for this function is for userspace or other
228 * kernel code to communicate a particular performance requirement to
229 * a subsystem; then for the subsystem to communicate that requirement
230 * to something that is meaningful to the device driver; then for the
231 * device driver to convert that requirement to a clock rate, and to
232 * then call omap_pm_set_min_clk_rate().
234 * Users of this function (such as device drivers) should not simply
235 * call this function with some high clock rate to ensure "high
236 * performance." Rather, the device driver should take a performance
237 * constraint from its subsystem, such as "render at least X polygons
238 * per second," and use some formula or table to convert that into a
239 * clock rate constraint given the hardware type and hardware
240 * revision. Device drivers or subsystems should not assume that they
241 * know how to make a power/performance tradeoff - some device use
242 * cases may tolerate a lower-fidelity device function for lower power
243 * consumption; others may demand a higher-fidelity device function,
244 * no matter what the power consumption.
246 * Multiple calls to omap_pm_set_min_clk_rate() will replace the
247 * previous rate value for the device @dev. To remove the minimum clock
248 * rate constraint for the device, call with r = 0.
250 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
251 * is not satisfiable, or 0 upon success.
253 int omap_pm_set_min_clk_rate(struct device
*dev
, struct clk
*c
, long r
);
256 * DSP Bridge-specific constraints
260 * omap_pm_dsp_get_opp_table - get OPP->DSP clock frequency table
262 * Intended for use by DSPBridge. Returns an array of OPP->DSP clock
263 * frequency entries. The final item in the array should have .rate =
266 const struct omap_opp
*omap_pm_dsp_get_opp_table(void);
269 * omap_pm_dsp_set_min_opp - receive desired OPP target ID from DSP Bridge
270 * @opp_id: target DSP OPP ID
272 * Set a minimum OPP ID for the DSP. This is intended to be called
273 * only from the DSP Bridge MPU-side driver. Unfortunately, the only
274 * information that code receives from the DSP/BIOS load estimator is the
275 * target OPP ID; hence, this interface. No return value.
277 void omap_pm_dsp_set_min_opp(u8 opp_id
);
280 * omap_pm_dsp_get_opp - report the current DSP OPP ID
282 * Report the current OPP for the DSP. Since on OMAP3, the DSP and
283 * MPU share a single voltage domain, the OPP ID returned back may
284 * represent a higher DSP speed than the OPP requested via
285 * omap_pm_dsp_set_min_opp().
287 * Returns the current VDD1 OPP ID, or 0 upon error.
289 u8
omap_pm_dsp_get_opp(void);
293 * CPUFreq-originated constraint
295 * In the future, this should be handled by custom OPP clocktype
300 * omap_pm_cpu_get_freq_table - return a cpufreq_frequency_table array ptr
302 * Provide a frequency table usable by CPUFreq for the current chip/board.
303 * Returns a pointer to a struct cpufreq_frequency_table array or NULL
306 struct cpufreq_frequency_table
**omap_pm_cpu_get_freq_table(void);
309 * omap_pm_cpu_set_freq - set the current minimum MPU frequency
310 * @f: MPU frequency in Hz
312 * Set the current minimum CPU frequency. The actual CPU frequency
313 * used could end up higher if the DSP requested a higher OPP.
314 * Intended to be called by plat-omap/cpu_omap.c:omap_target(). No
317 void omap_pm_cpu_set_freq(unsigned long f
);
320 * omap_pm_cpu_get_freq - report the current CPU frequency
322 * Returns the current MPU frequency, or 0 upon error.
324 unsigned long omap_pm_cpu_get_freq(void);
328 * Device context loss tracking
332 * omap_pm_get_dev_context_loss_count - return count of times dev has lost ctx
333 * @dev: struct device *
335 * This function returns the number of times that the device @dev has
336 * lost its internal context. This generally occurs on a powerdomain
337 * transition to OFF. Drivers use this as an optimization to avoid restoring
338 * context if the device hasn't lost it. To use, drivers should initially
339 * call this in their context save functions and store the result. Early in
340 * the driver's context restore function, the driver should call this function
341 * again, and compare the result to the stored counter. If they differ, the
342 * driver must restore device context. If the number of context losses
343 * exceeds the maximum positive integer, the function will wrap to 0 and
344 * continue counting. Returns the number of context losses for this device,
345 * or negative value upon error.
347 int omap_pm_get_dev_context_loss_count(struct device
*dev
);
349 void omap_pm_enable_off_mode(void);
350 void omap_pm_disable_off_mode(void);