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Commit 853116a1 authored by David Brownell's avatar David Brownell Committed by Liam Girdwood
Browse files

regulator: add get_status() 



Based on previous LKML discussions:

 * Update docs for regulator sysfs class attributes to highlight
   the fact that all current attributes are intended to be control
   inputs, including notably "state" and "opmode" which previously
   implied otherwise.

 * Define a new regulator driver get_status() method, which is the
   first method reporting regulator outputs instead of inputs.
   It can report on/off and error status; or instead of simply
   "on", report the actual operating mode.

For the moment, this is a sysfs-only interface, not accessible to
regulator clients.  Such clients can use the current notification
interfaces to detect errors, if the regulator reports them.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent 93e14baa

Documentation/ABI/testing/sysfs-class-regulator

+48 −9
Original line number Diff line number Diff line
@@ -4,8 +4,8 @@ KernelVersion: 2.6.26 
Contact:	Liam Girdwood <lrg@slimlogic.co.uk>

Description:

		Some regulator directories will contain a field called

		state. This reports the regulator enable status, for

		regulators which can report that value.

		state. This reports the regulator enable control, for

		regulators which can report that input value.



		This will be one of the following strings:
@@ -14,16 +14,54 @@ Description: 
		'unknown'



		'enabled' means the regulator output is ON and is supplying

		power to the system.

		power to the system (assuming no error prevents it).



		'disabled' means the regulator output is OFF and is not

		supplying power to the system..

		supplying power to the system (unless some non-Linux

		control has enabled it).



		'unknown' means software cannot determine the state, or

		the reported state is invalid.



		NOTE: this field can be used in conjunction with microvolts

		and microamps to determine regulator output levels.

		or microamps to determine configured regulator output levels.





What:		/sys/class/regulator/.../status

Description:

		Some regulator directories will contain a field called

		"status". This reports the current regulator status, for

		regulators which can report that output value.



		This will be one of the following strings:



			off

			on

			error

			fast

			normal

			idle

			standby



		"off" means the regulator is not supplying power to the

		system.



		"on" means the regulator is supplying power to the system,

		and the regulator can't report a detailed operation mode.



		"error" indicates an out-of-regulation status such as being

		disabled due to thermal shutdown, or voltage being unstable

		because of problems with the input power supply.



		"fast", "normal", "idle", and "standby" are all detailed

		regulator operation modes (described elsewhere).  They

		imply "on", but provide more detail.



		Note that regulator status is a function of many inputs,

		not limited to control inputs from Linux.  For example,

		the actual load presented may trigger "error" status; or

		a regulator may be enabled by another user, even though

		Linux did not enable it.





What:		/sys/class/regulator/.../type
@@ -58,7 +96,7 @@ Description: 
		Some regulator directories will contain a field called

		microvolts. This holds the regulator output voltage setting

		measured in microvolts (i.e. E-6 Volts), for regulators

		which can report that voltage.

		which can report the control input for voltage.



		NOTE: This value should not be used to determine the regulator

		output voltage level as this value is the same regardless of
@@ -73,7 +111,7 @@ Description: 
		Some regulator directories will contain a field called

		microamps. This holds the regulator output current limit

		setting measured in microamps (i.e. E-6 Amps), for regulators

		which can report that current.

		which can report the control input for a current limit.



		NOTE: This value should not be used to determine the regulator

		output current level as this value is the same regardless of
@@ -87,7 +125,7 @@ Contact: Liam Girdwood <lrg@slimlogic.co.uk> 
Description:

		Some regulator directories will contain a field called

		opmode. This holds the current regulator operating mode,

		for regulators which can report it.

		for regulators which can report that control input value.



		The opmode value can be one of the following strings:
@@ -101,7 +139,8 @@ Description: 


		NOTE: This value should not be used to determine the regulator

		output operating mode as this value is the same regardless of

		whether the regulator is enabled or disabled.

		whether the regulator is enabled or disabled.  A "status"

		attribute may be available to determine the actual mode.





What:		/sys/class/regulator/.../min_microvolts

drivers/regulator/core.c

+46 −0
Original line number Diff line number Diff line
@@ -312,6 +312,47 @@ static ssize_t regulator_state_show(struct device *dev, 
}

static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);



static ssize_t regulator_status_show(struct device *dev,

				   struct device_attribute *attr, char *buf)

{

	struct regulator_dev *rdev = dev_get_drvdata(dev);

	int status;

	char *label;



	status = rdev->desc->ops->get_status(rdev);

	if (status < 0)

		return status;



	switch (status) {

	case REGULATOR_STATUS_OFF:

		label = "off";

		break;

	case REGULATOR_STATUS_ON:

		label = "on";

		break;

	case REGULATOR_STATUS_ERROR:

		label = "error";

		break;

	case REGULATOR_STATUS_FAST:

		label = "fast";

		break;

	case REGULATOR_STATUS_NORMAL:

		label = "normal";

		break;

	case REGULATOR_STATUS_IDLE:

		label = "idle";

		break;

	case REGULATOR_STATUS_STANDBY:

		label = "standby";

		break;

	default:

		return -ERANGE;

	}



	return sprintf(buf, "%s\n", label);

}

static DEVICE_ATTR(status, 0444, regulator_status_show, NULL);



static ssize_t regulator_min_uA_show(struct device *dev,

				    struct device_attribute *attr, char *buf)

{
@@ -1744,6 +1785,11 @@ static int add_regulator_attributes(struct regulator_dev *rdev) 
		if (status < 0)

			return status;

	}

	if (ops->get_status) {

		status = device_create_file(dev, &dev_attr_status);

		if (status < 0)

			return status;

	}



	/* some attributes are type-specific */

	if (rdev->desc->type == REGULATOR_CURRENT) {

include/linux/regulator/driver.h

+17 −0
Original line number Diff line number Diff line
@@ -21,6 +21,17 @@ 
struct regulator_dev;

struct regulator_init_data;



enum regulator_status {

	REGULATOR_STATUS_OFF,

	REGULATOR_STATUS_ON,

	REGULATOR_STATUS_ERROR,

	/* fast/normal/idle/standby are flavors of "on" */

	REGULATOR_STATUS_FAST,

	REGULATOR_STATUS_NORMAL,

	REGULATOR_STATUS_IDLE,

	REGULATOR_STATUS_STANDBY,

};



/**

 * struct regulator_ops - regulator operations.

 *
@@ -72,6 +83,12 @@ struct regulator_ops { 
	int (*set_mode) (struct regulator_dev *, unsigned int mode);

	unsigned int (*get_mode) (struct regulator_dev *);



	/* report regulator status ... most other accessors report

	 * control inputs, this reports results of combining inputs

	 * from Linux (and other sources) with the actual load.

	 */

	int (*get_status)(struct regulator_dev *);



	/* get most efficient regulator operating mode for load */

	unsigned int (*get_optimum_mode) (struct regulator_dev *, int input_uV,

					  int output_uV, int load_uA);