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Diffstat (limited to 'arch/arm/mach-omap2/omap-pm.h')
-rw-r--r-- | arch/arm/mach-omap2/omap-pm.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/omap-pm.h b/arch/arm/mach-omap2/omap-pm.h new file mode 100644 index 000000000000..67faa7b8fe92 --- /dev/null +++ b/arch/arm/mach-omap2/omap-pm.h @@ -0,0 +1,352 @@ +/* + * 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 negative value upon error. + */ +int 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 |