summaryrefslogtreecommitdiffstats
path: root/Documentation/power/regulator/consumer.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/power/regulator/consumer.txt')
-rw-r--r--Documentation/power/regulator/consumer.txt182
1 files changed, 0 insertions, 182 deletions
diff --git a/Documentation/power/regulator/consumer.txt b/Documentation/power/regulator/consumer.txt
deleted file mode 100644
index 55c4175..0000000
--- a/Documentation/power/regulator/consumer.txt
+++ /dev/null
@@ -1,182 +0,0 @@
-Regulator Consumer Driver Interface
-===================================
-
-This text describes the regulator interface for consumer device drivers.
-Please see overview.txt for a description of the terms used in this text.
-
-
-1. Consumer Regulator Access (static & dynamic drivers)
-=======================================================
-
-A consumer driver can get access to its supply regulator by calling :-
-
-regulator = regulator_get(dev, "Vcc");
-
-The consumer passes in its struct device pointer and power supply ID. The core
-then finds the correct regulator by consulting a machine specific lookup table.
-If the lookup is successful then this call will return a pointer to the struct
-regulator that supplies this consumer.
-
-To release the regulator the consumer driver should call :-
-
-regulator_put(regulator);
-
-Consumers can be supplied by more than one regulator e.g. codec consumer with
-analog and digital supplies :-
-
-digital = regulator_get(dev, "Vcc"); /* digital core */
-analog = regulator_get(dev, "Avdd"); /* analog */
-
-The regulator access functions regulator_get() and regulator_put() will
-usually be called in your device drivers probe() and remove() respectively.
-
-
-2. Regulator Output Enable & Disable (static & dynamic drivers)
-====================================================================
-
-A consumer can enable its power supply by calling:-
-
-int regulator_enable(regulator);
-
-NOTE: The supply may already be enabled before regulator_enabled() is called.
-This may happen if the consumer shares the regulator or the regulator has been
-previously enabled by bootloader or kernel board initialization code.
-
-A consumer can determine if a regulator is enabled by calling :-
-
-int regulator_is_enabled(regulator);
-
-This will return > zero when the regulator is enabled.
-
-
-A consumer can disable its supply when no longer needed by calling :-
-
-int regulator_disable(regulator);
-
-NOTE: This may not disable the supply if it's shared with other consumers. The
-regulator will only be disabled when the enabled reference count is zero.
-
-Finally, a regulator can be forcefully disabled in the case of an emergency :-
-
-int regulator_force_disable(regulator);
-
-NOTE: this will immediately and forcefully shutdown the regulator output. All
-consumers will be powered off.
-
-
-3. Regulator Voltage Control & Status (dynamic drivers)
-======================================================
-
-Some consumer drivers need to be able to dynamically change their supply
-voltage to match system operating points. e.g. CPUfreq drivers can scale
-voltage along with frequency to save power, SD drivers may need to select the
-correct card voltage, etc.
-
-Consumers can control their supply voltage by calling :-
-
-int regulator_set_voltage(regulator, min_uV, max_uV);
-
-Where min_uV and max_uV are the minimum and maximum acceptable voltages in
-microvolts.
-
-NOTE: this can be called when the regulator is enabled or disabled. If called
-when enabled, then the voltage changes instantly, otherwise the voltage
-configuration changes and the voltage is physically set when the regulator is
-next enabled.
-
-The regulators configured voltage output can be found by calling :-
-
-int regulator_get_voltage(regulator);
-
-NOTE: get_voltage() will return the configured output voltage whether the
-regulator is enabled or disabled and should NOT be used to determine regulator
-output state. However this can be used in conjunction with is_enabled() to
-determine the regulator physical output voltage.
-
-
-4. Regulator Current Limit Control & Status (dynamic drivers)
-===========================================================
-
-Some consumer drivers need to be able to dynamically change their supply
-current limit to match system operating points. e.g. LCD backlight driver can
-change the current limit to vary the backlight brightness, USB drivers may want
-to set the limit to 500mA when supplying power.
-
-Consumers can control their supply current limit by calling :-
-
-int regulator_set_current_limit(regulator, min_uA, max_uA);
-
-Where min_uA and max_uA are the minimum and maximum acceptable current limit in
-microamps.
-
-NOTE: this can be called when the regulator is enabled or disabled. If called
-when enabled, then the current limit changes instantly, otherwise the current
-limit configuration changes and the current limit is physically set when the
-regulator is next enabled.
-
-A regulators current limit can be found by calling :-
-
-int regulator_get_current_limit(regulator);
-
-NOTE: get_current_limit() will return the current limit whether the regulator
-is enabled or disabled and should not be used to determine regulator current
-load.
-
-
-5. Regulator Operating Mode Control & Status (dynamic drivers)
-=============================================================
-
-Some consumers can further save system power by changing the operating mode of
-their supply regulator to be more efficient when the consumers operating state
-changes. e.g. consumer driver is idle and subsequently draws less current
-
-Regulator operating mode can be changed indirectly or directly.
-
-Indirect operating mode control.
---------------------------------
-Consumer drivers can request a change in their supply regulator operating mode
-by calling :-
-
-int regulator_set_optimum_mode(struct regulator *regulator, int load_uA);
-
-This will cause the core to recalculate the total load on the regulator (based
-on all its consumers) and change operating mode (if necessary and permitted)
-to best match the current operating load.
-
-The load_uA value can be determined from the consumers datasheet. e.g.most
-datasheets have tables showing the max current consumed in certain situations.
-
-Most consumers will use indirect operating mode control since they have no
-knowledge of the regulator or whether the regulator is shared with other
-consumers.
-
-Direct operating mode control.
-------------------------------
-Bespoke or tightly coupled drivers may want to directly control regulator
-operating mode depending on their operating point. This can be achieved by
-calling :-
-
-int regulator_set_mode(struct regulator *regulator, unsigned int mode);
-unsigned int regulator_get_mode(struct regulator *regulator);
-
-Direct mode will only be used by consumers that *know* about the regulator and
-are not sharing the regulator with other consumers.
-
-
-6. Regulator Events
-===================
-Regulators can notify consumers of external events. Events could be received by
-consumers under regulator stress or failure conditions.
-
-Consumers can register interest in regulator events by calling :-
-
-int regulator_register_notifier(struct regulator *regulator,
- struct notifier_block *nb);
-
-Consumers can uregister interest by calling :-
-
-int regulator_unregister_notifier(struct regulator *regulator,
- struct notifier_block *nb);
-
-Regulators use the kernel notifier framework to send event to their interested
-consumers.