linux/arch/arm/mach-omap2/omap-pm.h
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   1/*
   2 * omap-pm.h - OMAP power management interface
   3 *
   4 * Copyright (C) 2008-2010 Texas Instruments, Inc.
   5 * Copyright (C) 2008-2010 Nokia Corporation
   6 * Paul Walmsley
   7 *
   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,
  11 * Richard Woodruff
  12 */
  13
  14#ifndef ASM_ARM_ARCH_OMAP_OMAP_PM_H
  15#define ASM_ARM_ARCH_OMAP_OMAP_PM_H
  16
  17#include <linux/device.h>
  18#include <linux/cpufreq.h>
  19#include <linux/clk.h>
  20#include <linux/pm_opp.h>
  21
  22/*
  23 * agent_id values for use with omap_pm_set_min_bus_tput():
  24 *
  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.
  29 */
  30#define OCP_TARGET_AGENT                1
  31#define OCP_INITIATOR_AGENT             2
  32
  33/**
  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
  38 *
  39 * Initialize anything that must be configured before the clock
  40 * framework starts.  The "_if_" is to avoid name collisions with the
  41 * PM idle-loop code.
  42 */
  43int __init omap_pm_if_early_init(void);
  44
  45/**
  46 * omap_pm_if_init - OMAP PM init code called after clock fw init
  47 *
  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.
  50 */
  51int __init omap_pm_if_init(void);
  52
  53/*
  54 * Device-driver-originated constraints (via board-*.c files, platform_data)
  55 */
  56
  57
  58/**
  59 * omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency
  60 * @dev: struct device * requesting the constraint
  61 * @t: maximum MPU wakeup latency in microseconds
  62 *
  63 * Request that the maximum interrupt latency for the MPU to be no
  64 * greater than @t microseconds. "Interrupt latency" in this case is
  65 * defined as the elapsed time from the occurrence of a hardware or
  66 * timer interrupt to the time when the device driver's interrupt
  67 * service routine has been entered by the MPU.
  68 *
  69 * It is intended that underlying PM code will use this information to
  70 * determine what power state to put the MPU powerdomain into, and
  71 * possibly the CORE powerdomain as well, since interrupt handling
  72 * code currently runs from SDRAM.  Advanced PM or board*.c code may
  73 * also configure interrupt controller priorities, OCP bus priorities,
  74 * CPU speed(s), etc.
  75 *
  76 * This function will not affect device wakeup latency, e.g., time
  77 * elapsed from when a device driver enables a hardware device with
  78 * clk_enable(), to when the device is ready for register access or
  79 * other use.  To control this device wakeup latency, use
  80 * omap_pm_set_max_dev_wakeup_lat()
  81 *
  82 * Multiple calls to omap_pm_set_max_mpu_wakeup_lat() will replace the
  83 * previous t value.  To remove the latency target for the MPU, call
  84 * with t = -1.
  85 *
  86 * XXX This constraint will be deprecated soon in favor of the more
  87 * general omap_pm_set_max_dev_wakeup_lat()
  88 *
  89 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
  90 * is not satisfiable, or 0 upon success.
  91 */
  92int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t);
  93
  94
  95/**
  96 * omap_pm_set_min_bus_tput - set minimum bus throughput needed by device
  97 * @dev: struct device * requesting the constraint
  98 * @tbus_id: interconnect to operate on (OCP_{INITIATOR,TARGET}_AGENT)
  99 * @r: minimum throughput (in KiB/s)
 100 *
 101 * Request that the minimum data throughput on the OCP interconnect
 102 * attached to device @dev interconnect agent @tbus_id be no less
 103 * than @r KiB/s.
 104 *
 105 * It is expected that the OMAP PM or bus code will use this
 106 * information to set the interconnect clock to run at the lowest
 107 * possible speed that satisfies all current system users.  The PM or
 108 * bus code will adjust the estimate based on its model of the bus, so
 109 * device driver authors should attempt to specify an accurate
 110 * quantity for their device use case, and let the PM or bus code
 111 * overestimate the numbers as necessary to handle request/response
 112 * latency, other competing users on the system, etc.  On OMAP2/3, if
 113 * a driver requests a minimum L4 interconnect speed constraint, the
 114 * code will also need to add an minimum L3 interconnect speed
 115 * constraint,
 116 *
 117 * Multiple calls to omap_pm_set_min_bus_tput() will replace the
 118 * previous rate value for this device.  To remove the interconnect
 119 * throughput restriction for this device, call with r = 0.
 120 *
 121 * Returns -EINVAL for an invalid argument, -ERANGE if the constraint
 122 * is not satisfiable, or 0 upon success.
 123 */
 124int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r);
 125
 126
 127/*
 128 * CPUFreq-originated constraint
 129 *
 130 * In the future, this should be handled by custom OPP clocktype
 131 * functions.
 132 */
 133
 134
 135/*
 136 * Device context loss tracking
 137 */
 138
 139/**
 140 * omap_pm_get_dev_context_loss_count - return count of times dev has lost ctx
 141 * @dev: struct device *
 142 *
 143 * This function returns the number of times that the device @dev has
 144 * lost its internal context.  This generally occurs on a powerdomain
 145 * transition to OFF.  Drivers use this as an optimization to avoid restoring
 146 * context if the device hasn't lost it.  To use, drivers should initially
 147 * call this in their context save functions and store the result.  Early in
 148 * the driver's context restore function, the driver should call this function
 149 * again, and compare the result to the stored counter.  If they differ, the
 150 * driver must restore device context.   If the number of context losses
 151 * exceeds the maximum positive integer, the function will wrap to 0 and
 152 * continue counting.  Returns the number of context losses for this device,
 153 * or negative value upon error.
 154 */
 155int omap_pm_get_dev_context_loss_count(struct device *dev);
 156
 157void omap_pm_enable_off_mode(void);
 158void omap_pm_disable_off_mode(void);
 159
 160#endif
 161