From 853116a10544206b6b2cf42ebc9d78fba2668888 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 14 Jan 2009 23:03:17 -0800 Subject: [PATCH] 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: David Brownell Signed-off-by: Liam Girdwood --- .../ABI/testing/sysfs-class-regulator | 57 ++++++++++++++++--- drivers/regulator/core.c | 46 +++++++++++++++ include/linux/regulator/driver.h | 17 ++++++ 3 files changed, 111 insertions(+), 9 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator index 873ef1fc1569..e091fa873792 100644 --- a/Documentation/ABI/testing/sysfs-class-regulator +++ b/Documentation/ABI/testing/sysfs-class-regulator @@ -4,8 +4,8 @@ KernelVersion: 2.6.26 Contact: Liam Girdwood 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 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 diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index f511a406fcaa..0ff95c3ccf5b 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -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) { diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index 2dae05705f13..6e957aae7629 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -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); -- 2.20.1