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Linux Kernel
3.7.1
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Linux Kernel
3.7.1
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#include <linux/init.h>#include <linux/cpufreq.h>#include <linux/device.h>#include <linux/platform_device.h>#include <plat/omap-pm.h>#include <plat/omap_device.h>Go to the source code of this file.
Functions | |
| int | omap_pm_set_max_mpu_wakeup_lat (struct device *dev, long t) |
| int | omap_pm_set_min_bus_tput (struct device *dev, u8 agent_id, unsigned long r) |
| int | omap_pm_set_max_dev_wakeup_lat (struct device *req_dev, struct device *dev, long t) |
| int | omap_pm_set_max_sdma_lat (struct device *dev, long t) |
| int | omap_pm_set_min_clk_rate (struct device *dev, struct clk *c, long r) |
| struct omap_opp * | omap_pm_dsp_get_opp_table (void) |
| void | omap_pm_dsp_set_min_opp (u8 opp_id) |
| u8 | omap_pm_dsp_get_opp (void) |
| struct cpufreq_frequency_table ** | omap_pm_cpu_get_freq_table (void) |
| void | omap_pm_cpu_set_freq (unsigned long f) |
| unsigned long | omap_pm_cpu_get_freq (void) |
| void | omap_pm_enable_off_mode (void) |
| void | omap_pm_disable_off_mode (void) |
| int | omap_pm_get_dev_context_loss_count (struct device *dev) |
| int __init | omap_pm_if_early_init (void) |
| int __init | omap_pm_if_init (void) |
| void | omap_pm_if_exit (void) |
omap_pm_cpu_get_freq - report the current CPU frequency
Returns the current MPU frequency, or 0 upon error.
Definition at line 274 of file omap-pm-noop.c.
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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.
Definition at line 241 of file omap-pm-noop.c.
omap_pm_cpu_set_freq - set the current minimum MPU frequency : 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.
Definition at line 254 of file omap-pm-noop.c.
omap_pm_disable_off_mode - notify OMAP PM that off-mode is disabled
Intended for use only by OMAP PM core code to notify this layer that off mode has been disabled.
Definition at line 302 of file omap-pm-noop.c.
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.
Definition at line 219 of file omap-pm-noop.c.
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.
Definition at line 182 of file omap-pm-noop.c.
omap_pm_dsp_set_min_opp - receive desired OPP target ID from DSP Bridge : 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.
Definition at line 194 of file omap-pm-noop.c.
omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
Intended for use only by OMAP PM core code to notify this layer that off mode has been enabled.
Definition at line 291 of file omap-pm-noop.c.
omap_pm_get_dev_context_loss_count - return count of times dev has lost ctx : struct device *
This function returns the number of times that the device 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.
Definition at line 349 of file omap-pm-noop.c.
omap_pm_if_early_init - OMAP PM init code called before clock fw init : array ptr to struct omap_opp for MPU : array ptr to struct omap_opp for DSP : 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.
Definition at line 357 of file omap-pm-noop.c.
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.
Definition at line 368 of file omap-pm-noop.c.
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.
Definition at line 363 of file omap-pm-noop.c.
omap_pm_set_max_dev_wakeup_lat - set the maximum device enable latency : struct device * requesting the constraint, or NULL if none : struct device * to set the constraint one : maximum device wakeup latency in microseconds
Request that the maximum amount of time necessary for a device to become accessible after its clocks are enabled should be no greater than 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.
Definition at line 90 of file omap-pm-noop.c.
omap_pm_set_max_mpu_wakeup_lat - set the maximum MPU wakeup latency : struct device * requesting the constraint : maximum MPU wakeup latency in microseconds
Request that the maximum interrupt latency for the MPU to be no greater than 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.
Definition at line 36 of file omap-pm-noop.c.
omap_pm_set_max_sdma_lat - set the maximum system DMA transfer start latency : struct device * : 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.
Definition at line 121 of file omap-pm-noop.c.
omap_pm_set_min_bus_tput - set minimum bus throughput needed by device : struct device * requesting the constraint : interconnect to operate on (OCP_{INITIATOR,TARGET}_AGENT) : minimum throughput (in KiB/s)
Request that the minimum data throughput on the OCP interconnect attached to device interconnect agent be no less than 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.
Definition at line 64 of file omap-pm-noop.c.
omap_pm_set_min_clk_rate - set minimum clock rate requested by : struct device * requesting the constraint : struct clk * to set the minimum rate constraint on : minimum rate in Hz
Request that the minimum clock rate on the device 's clk be no less than 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 . 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.
Definition at line 150 of file omap-pm-noop.c.
1.8.2