OMAP2/3 PM: create the OMAP PM interface and add a default OMAP PM no-op layer

The interface provides device drivers, CPUFreq, and DSPBridge with a
means of controlling OMAP power management parameters that are not yet
supported by the Linux PM PMQoS interface.  Copious documentation is
in the patch in Documentation/arm/OMAP/omap_pm and the interface
header file, arch/arm/plat-omap/include/mach/omap-pm.h.

Thanks to Rajendra Nayak <rnayak@ti.com> for adding CORE (VDD2) OPP
support and moving the OPP table initialization earlier in the event
that the clock code needs them.  Thanks to Tero Kristo
<tero.kristo@nokia.com> for fixing the parameter check in
omap_pm_set_min_bus_tput().  Jouni signed off on Tero's patch.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Jouni Högander <jouni.hogander@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Igor Stoppa <igor.stoppa@nokia.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Anand Sawant <sawant@ti.com>
Cc: Sakari Poussa <sakari.poussa@nokia.com>
Cc: Veeramanikandan Raju <veera@ti.com>
Cc: Karthik Dasu <karthik-dp@ti.com>

1 files changed, 301 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/include/mach/omap-pm.h b/arch/arm/plat-omap/include/mach/omap-pm.h
new file mode 100644
index 000000000000..3ee41d711492
--- /dev/null
+++ b/arch/arm/plat-omap/include/mach/omap-pm.h
@@ -0,0 +1,301 @@
+/*
+ * omap-pm.h - OMAP power management interface
+ *
+ * Copyright (C) 2008-2009 Texas Instruments, Inc.
+ * Copyright (C) 2008-2009 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 "powerdomain.h"
+
+/**
+ * struct omap_opp - clock frequency-to-OPP ID table for DSP, MPU
+ * @rate: target clock rate
+ * @opp_id: OPP ID
+ * @min_vdd: minimum VDD1 voltage (in millivolts) for this OPP
+ *
+ * Operating performance point data.  Can vary by OMAP chip and board.
+ */
+struct omap_opp {
+        unsigned long rate;
+        u8 opp_id;
+        u16 min_vdd;
+};
+
+extern struct omap_opp *mpu_opps;
+extern struct omap_opp *dsp_opps;
+extern struct omap_opp *l3_opps;
+
+/*
+ * 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(struct omap_opp *mpu_opp_table,
+                                 struct omap_opp *dsp_opp_table,
+                                 struct omap_opp *l3_opp_table);
+
+/**
+ * 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
+ * set_max_dev_wakeup_lat()
+ *
+ * Multiple calls to set_max_mpu_wakeup_lat() will replace the
+ * previous t value.  To remove the latency target for the MPU, call
+ * with t = -1.
+ *
+ * No return value.
+ */
+void 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 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.
+ *
+ * No return value.
+ */
+void 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
+ * @dev: struct device *
+ * @t: 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 '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 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.
+ *
+ * No return value.
+ */
+void omap_pm_set_max_dev_wakeup_lat(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.
+ *
+ * No return value.
+ */
+void omap_pm_set_max_sdma_lat(struct device *dev, long t);
+
+
+/*
+ * 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 -EINVAL upon error.
+ */
+int omap_pm_get_dev_context_loss_count(struct device *dev);
+
+
+#endif