linux-toradex.git/include/linux/power_supply.h, branch v4.16-rc4

power: supply: Add power_supply_set_input_current_limit_from_supplier helper

2017-08-29T10:24:52+00:00

On some devices the USB Type-C port power (USB PD 2.0) negotiation is
done by a separate port-controller IC, while the current limit is
controlled through another (charger) IC.

It has been decided to model this by modelling the external Type-C
power brick (adapter/charger) as a power-supply class device which
supplies the charger-IC, with its voltage-now and current-max representing
the negotiated voltage and max current draw.

This commit adds a power_supply_set_input_current_limit_from_supplier
helper function which charger power-supply drivers can call to get
the max-current from their supplier and have this applied
through their set_property call-back to their input-current-limit.

Signed-off-by: Hans de Goede 
Signed-off-by: Sebastian Reichel

power: supply: core: Add power_supply_prop_precharge

2017-06-08T14:29:28+00:00

Battery chargers use POWER_SUPPLY_PROP_PRECHARGE_CURRENT
Clarify related item POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT

Signed-off-by: Liam Breck 
Signed-off-by: Sebastian Reichel

power: supply: core: Add power_supply_battery_info and API

2017-06-08T14:29:28+00:00

power_supply_get_battery_info() reads battery data from devicetree.
struct power_supply_battery_info provides battery data to drivers.
Its fields correspond to elements in enum power_supply_property.
Drivers may surface battery data in sysfs via corresponding
POWER_SUPPLY_PROP_* fields.

Signed-off-by: Matt Ranostay 
Signed-off-by: Liam Breck 
Signed-off-by: Sebastian Reichel

power: supply: Add Apple Brick ID power supply type

2017-06-08T11:05:22+00:00

Apple currently supports three very common USB chargers:
https://www.apple.com/power-adapters/

These chargers implement a proprietary Apple method for advertising
1A, 2.1A, and 2.4A at 5V called "Brick ID".
In addition, 3rd parties implement the same charging method in many
charging accessories that work with iOS devices.

Devices that have charger detection chips such as the Pericom PI3USB9281,
eg. Google Chromebook Pixel 2015, are capable of detecting
these chargers, so let's add a type to facilicate passing that info
up to userspace.

This adds a separate power supply type for Apple's proprietary
"Brick ID" charging method.

Signed-off-by: Benson Leung 
Signed-off-by: Sebastian Reichel

power_supply: fix return value of get_property

2016-07-01T20:44:34+00:00

power_supply_get_property() should ideally return -EAGAIN if it is
called while the power_supply is being registered. There was no way
previously to determine if use_cnt == 0 meant that the power_supply
wasn't fully registered yet, or if it had already been unregistered.

Add a new boolean to the power_supply struct to simply show if
registration is completed. Lastly, modify the check in
power_supply_show_property() to also ignore -EAGAIN when so it
doesn't complain about not returning the property.

Signed-off-by: Rhyland Klein 
Signed-off-by: Sebastian Reichel

power_supply: Add types for USB Type C and PD chargers

2016-02-15T06:02:32+00:00

This adds power supply types for USB chargers defined in
the USB Type-C Specification 1.1 and in the
USB Power Delivery Specification Revision 2.0 V1.1.

The following are added :
POWER_SUPPLY_TYPE_USB_TYPE_C,	/* Type C Port */
POWER_SUPPLY_TYPE_USB_PD,	/* Power Delivery Port */
POWER_SUPPLY_TYPE_USB_PD_DRP,	/* PD Dual Role Port */

Signed-off-by: Benson Leung 
[tomeu: remove the mention to Type C from the comments]
Signed-off-by: Tomeu Vizoso 
Reviewed-by: Alec Berg 
Reviewed-by: Vincent Palatin 
Reviewed-by: Todd Broch 
Signed-off-by: Sebastian Reichel

power: Add devm_power_supply_get_by_phandle() helper function

2015-06-10T14:15:54+00:00

This commit adds a resource-managed version of the
power_supply_get_by_phandle() function.

Signed-off-by: Hans de Goede 
Signed-off-by: Sebastian Reichel

power_supply: sysfs: Bring back write to writeable properties

2015-06-10T14:10:59+00:00

The fix for NULL pointer exception related to calling uevent for not
finished probe caused to set all writeable properties as non-writeable.
This was caused by checking if property is writeable before the initial
increase of power supply usage counter and in the same time using
wrapper over property_is_writeable(). The wrapper returns ENODEV if the
usage counter is still 0.

The call trace looked like:
  device probe:
    power_supply_register()
      use_cnt = 0;
      device_add()
        create sysfs entries
          power_supply_attr_is_visible()
            power_supply_property_is_writeable()
              if (use_cnt == 0) return -ENODEV;
      use_cnt++;

Replace the usage of wrapper with direct call to property_is_writeable()
from driver. This should be safe call during device probe because
implementations of this callback just return 0/1 for different
properties and they do not access any of the driver's internal data.

Fixes: 8e59c7f23410 ("power_supply: Fix NULL pointer dereference during bq27x00_battery probe")
Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Sebastian Reichel

power_supply: Fix possible NULL pointer dereference on early uevent

2015-05-21T13:41:09+00:00

Don't call the power_supply_changed() from power_supply_register() when
parent is still probing because it may lead to accessing parent too
early.

In bq27x00_battery this caused NULL pointer exception because uevent of
power_supply_changed called back the the get_property() method provided
by the driver. The get_property() method accessed pointer which should
be returned by power_supply_register().

Starting from bq27x00_battery_probe():
  di->bat = power_supply_register()
    power_supply_changed()
      kobject_uevent()
        power_supply_uevent()
          power_supply_show_property()
            power_supply_get_property()
              bq27x00_battery_get_property()
                dereference of di->bat which is NULL here

The dereference of di->bat (value returned by power_supply_register())
is the currently visible problem. However calling back the methods
provided by driver before ending the probe may lead to accessing other
driver-related data which is not yet initialized.

The call to power_supply_changed() is postponed till probing ends -
mutex of parent device is released.

Reported-by: H. Nikolaus Schaller 
Signed-off-by: Krzysztof Kozlowski 
Fixes: 297d716f6260 ("power_supply: Change ownership from driver to core")
Tested-By: Dr. H. Nikolaus Schaller 
Signed-off-by: Sebastian Reichel

power_supply: Add power_supply_put for decrementing device reference counter

2015-03-13T22:15:52+00:00

The power_supply_get_by_phandle() and power_supply_get_by_name() use
function class_find_device() for obtaining the reference to power
supply. Each use of class_find_device() increases the power supply's
device reference counter.

However the reference counter was not decreased by users of this API.
Thus final device_unregister() call from power_supply_unregister() could
not release the device and clean up its resources. This lead to memory
leak if at least once power_supply_get_by_*() was called between
registering and unregistering the power supply.

Add and document new API power_supply_put() for decrementing the
reference counter.

Signed-off-by: Krzysztof Kozlowski 
Acked-by: Pavel Machek 
Reviewed-by: Bartlomiej Zolnierkiewicz 
Reviewed-by: Sebastian Reichel 
Signed-off-by: Sebastian Reichel