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: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

power: supply: core: Delete two error messages for a failed memory allocation in power_supply_check_supplies()

Omit extra messages for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

Commit 2848e039 ("power: supply: Make power_supply_am_i_supplied return
-ENODEV if there are no suppliers") was supposed to make
power_supply_am_i_supplied() return -ENODEV when there are no supplies
which supply the supply passed to it.

But instead it will only return -ENODEV when there are no supplies at
all as data->count++; is incremented on every call of the iterator, rather
then only when __power_supply_is_supplied_by returns true. This commit
fixes this.

Fixes: 2848e039 ("power: supply: Make power_supply_am_i_supplied ...")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

File size before:
text	data	bss	dec   hex filename
4240	 200	 80	4520 11a8 drivers/power/supply/power_supply_core.o

File size After adding 'const':
text	data	bss	dec   hex filename
4296	 136	 80	4512 11a0 drivers/power/supply/power_supply_core.o
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

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: NMatt Ranostay <matt@ranostay.consulting>
Signed-off-by: NLiam Breck <kernel@networkimprov.net>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

On devicetree using platforms the devicetree can provide info on which
power-supplies supply another power-supply through phandles.

This commit adds support for providing this info on non devicetree
platforms through the platform code setting a supplied-from
device-property on the power-supplies parent device.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

It is sensible to assume that the hardware actually always has a
way of charging the battery so when power_supply_am_i_supplied does not
find any suppliers, that does not mean that there are none, but simply
that no power_supply-drivers are registered / bound for any suppliers for
the supply calling power_supply_am_i_supplied.

At which point a fuel-gauge driver calling power_supply_am_i_supplied()
cannot determine whether the battery is being charged or not.

Allow a caller of power_supply_am_i_supplied to differentiate between
there not being any suppliers, vs no suppliers being online by returning
-ENODEV if there are no suppliers matching supplied_to / supplied_from,
which allows fuel-gauge drivers to return POWER_SUPPLY_STATUS_UNKNOWN
rather then POWER_SUPPLY_STATUS_DISCHARGING if there are no suppliers.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>

In drivers/power/supply/ab8500_fg.c, fix two typos and adjust the function
name in two cases to correspond to the names of the defined functions.

In drivers/power/supply/power_supply_core.c, change two variable names to
the names of the corresponding parameters.

Issue detected using Coccinelle (http://coccinelle.lip6.fr/)
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

This moves all power supply drivers from drivers/power/
to drivers/power/supply/. The intention is a cleaner
source tree, since drivers/power/ also contains frameworks
unrelated to power supply, like adaptive voltage scaling.
Signed-off-by: NSebastian Reichel <sre@kernel.org>

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: NRhyland Klein <rklein@nvidia.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Change power_supply_read_temp() to use power_supply_get_property()
so that it will check the use_cnt and ensure it is > 0. The use_cnt
will be incremented at the end of __power_supply_register, so this
will block to case where get_property can be called before the supply
is fully registered. This fixes the issue show in the stack below:

[    1.452598] power_supply_read_temp+0x78/0x80
[    1.458680] thermal_zone_get_temp+0x5c/0x11c
[    1.464765] thermal_zone_device_update+0x34/0xb4
[    1.471195] thermal_zone_device_register+0x87c/0x8cc
[    1.477974] __power_supply_register+0x364/0x424
[    1.484317] power_supply_register_no_ws+0x10/0x18
[    1.490833] bq27xxx_battery_setup+0x10c/0x164
[    1.497003] bq27xxx_battery_i2c_probe+0xd0/0x1b0
[    1.503435] i2c_device_probe+0x174/0x240
[    1.509172] driver_probe_device+0x1fc/0x29c
[    1.515167] __driver_attach+0xa4/0xa8
[    1.520643] bus_for_each_dev+0x58/0x98
[    1.526204] driver_attach+0x20/0x28
[    1.531505] bus_add_driver+0x1c8/0x22c
[    1.537067] driver_register+0x68/0x108
[    1.542630] i2c_register_driver+0x38/0x7c
[    1.548457] bq27xxx_battery_i2c_driver_init+0x18/0x20
[    1.555321] do_one_initcall+0x38/0x12c
[    1.560886] kernel_init_freeable+0x148/0x1ec
[    1.566972] kernel_init+0x10/0xfc
[    1.572101] ret_from_fork+0x10/0x40

Also make the same change to ps_get_max_charge_cntl_limit() and
ps_get_cur_chrage_cntl_limit() to be safe. Lastly, change the return
value of power_supply_get_property() to -EAGAIN from -ENODEV if
use_cnt <= 0.

Fixes: 297d716f ("power_supply: Change ownership from driver to core")
Cc: stable@vger.kernel.org
Signed-off-by: NRhyland Klein <rklein@nvidia.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

The thermal code uses int, long and unsigned long for temperatures
in different places.

Using an unsigned type limits the thermal framework to positive
temperatures without need. Also several drivers currently will report
temperatures near UINT_MAX for temperatures below 0°C. This will probably
immediately shut the machine down due to overtemperature if started below
0°C.

'long' is 64bit on several architectures. This is not needed since INT_MAX °mC
is above the melting point of all known materials.

Consistently use a plain 'int' for temperatures throughout the thermal code and
the drivers. This only changes the places in the drivers where the temperature
is passed around as pointer, when drivers internally use another type this is
not changed.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Reviewed-by: NLukasz Majewski <l.majewski@samsung.com>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Reviewed-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NPeter Feuerer <peter@piie.net>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Peter Feuerer <peter@piie.net>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-acpi@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: lm-sensors@lm-sensors.org
Signed-off-by: NZhang Rui <rui.zhang@intel.com>

Signed-off-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

This commit adds a resource-managed version of the
power_supply_get_by_phandle() function.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

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: NH. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 297d716f ("power_supply: Change ownership from driver to core")
Tested-By: NDr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Power supply is often registered during probe of a driver. The
power_supply_register() returns pointer to newly allocated structure as
return value. However before returning the power_supply_register()
calls back the get_property() method provided by the driver through
uevent.

In that time the driver probe is still in progress and driver did not
assigned pointer to power supply to its local variables. This leads to
NULL pointer dereference from get_property() function.
Starting from bq27x00_battery_probe():
  di->bat = power_supply_register()
    device_add()
      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 first uevent of power supply (the one coming from device creation)
should not call back to the driver. To prevent that from happening,
increment the atomic use counter at the end of power_supply_register().
This means that power_supply_get_property() will return -ENODEV.

IMPORTANT:
The patch has impact on this first uevent sent from power supply because
it will not contain properties from power supply.

The uevent with properties will be sent later after indicating that
power supply has changed. This also has a race now, but will be fixed in
other patches.
Reported-by: NH. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 297d716f ("power_supply: Change ownership from driver to core")
Tested-By: NDr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Increment the power_supply.use_cnt usage counter on:
 - power_supply_get_by_phandle()
 - power_supply_get_by_name()
and decrement it on power_supply_put() call.

This helps tracking of valid usage of power supply instance by
consumers. The usage counter itself also allows safe calling of
power_supply_get_property-like functions even when driver unregisters
this power supply.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

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: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NSebastian Reichel <sre@kernel.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.

The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.

Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.

Instead let the core own the instance of struct 'power_supply'.  Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.

This solves invalid memory references in following race condition
scenario:

Thread 1: charger manager
Thread 2: power supply driver, used by charger manager

THREAD 1 (charger manager)         THREAD 2 (power supply driver)
==========================         ==============================
psy = power_supply_get_by_name()
                                   Driver unbind, .remove
                                     power_supply_unregister()
                                     Device fully removed
psy->get_property()

The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.

This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):

$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[   55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   55.732584] pgd = d98d4000
[   55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[   55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[   55.746210] Modules linked in:
[   55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G        W       3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[   55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[   55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[   55.771647] PC is at 0x0
[   55.774182] LR is at charger_get_property+0x2f4/0x36c
[   55.779201] pc : [<00000000>]    lr : [<c034b0b4>]    psr: 60000013
[   55.779201] sp : daf55e90  ip : 00000003  fp : 00000000
[   55.790657] r10: 00000000  r9 : c06e2878  r8 : d9b26c68
[   55.795865] r7 : dad81610  r6 : daec7410  r5 : daf55ebc  r4 : 00000000
[   55.802367] r3 : 00000000  r2 : daf55ebc  r1 : 0000002a  r0 : d9b26c68
[   55.808879] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   55.815994] Control: 10c5387d  Table: 598d406a  DAC: 00000015
[   55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[   55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[   55.831795] 5e80:                                     60000013 c01459c4 0000002a c06f8ef8
[   55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[   55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[   55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[   55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[   55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[   55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[   55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[   55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[   55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[   55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[   55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[   55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c)
[   55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48)
[   55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104)
[   55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28)
[   55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484)
[   55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c)
[   55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100)
[   55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c)
[   55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48)
[   56.000626] Code: bad PC value
[   56.011652] ---[ end trace 7b64343fbdae8ef1 ]---
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

[for the nvec part]
Reviewed-by: NMarc Dietrich <marvin24@gmx.de>

[for compal-laptop.c]
Acked-by: NDarren Hart <dvhart@linux.intel.com>

[for the mfd part]
Acked-by: NLee Jones <lee.jones@linaro.org>

[for the hid part]
Acked-by: NJiri Kosina <jkosina@suse.cz>

[for the acpi part]
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Add simple wrappers for accessing power supply's function attributes:
 - get_property -> power_supply_get_property
 - set_property -> power_supply_set_property
 - property_is_writeable -> power_supply_property_is_writeable
 - external_power_changed -> power_supply_external_power_changed

This API along with atomic usage counter adds a safe way of accessing a
power supply from another driver. If power supply is unregistered after
obtaining reference to it by some driver, then the API wrappers won't be
executed in invalid (freed) context.

Next patch changing the ownership of power supply class is still needed
to fully fix race conditions in accessing freed power supply.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NSebastian Reichel <sre@kernel.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Add new structure 'power_supply_config' for holding run-time
initialization data like of_node, supplies and private driver data.

The power_supply_register() function is changed so all power supply
drivers need updating.

When registering the power supply this new 'power_supply_config' should be
used instead of directly initializing 'struct power_supply'. This allows
changing the ownership of power_supply structure from driver to the
power supply core in next patches.

When a driver does not use of_node or supplies then it should use NULL
as config. If driver uses of_node or supplies then it should allocate
config on stack and initialize it with proper values.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: NPavel Machek <pavel@ucw.cz>

[for the nvec part]
Reviewed-by: NMarc Dietrich <marvin24@gmx.de>

[for drivers/platform/x86/compal-laptop.c]
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>

[for drivers/hid/*]
Reviewed-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Allow drivers to store private data inside power_supply structure for
later usage in power supply operations.

Usage of driver private data is necessary to access driver's state
container object from power supply calls (like get_property()) if struct
'power_supply' is a stored there as a pointer, for example:

struct some_driver_info {
	struct i2c_client       *client;
	struct power_supply     *power_supply;
	...
}

In such case one cannot use container_of() and must store pointer to
state container as private data.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NSebastian Reichel <sre@kernel.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Using devm_power_supply_register allows the unregister to happen
automatically on error or final put.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Add a 'no_thermal' property to the power supply class. If true then
thermal zone won't be created for this power supply in
power_supply_register().

Power supply drivers may want to set it if they support
POWER_SUPPLY_PROP_TEMP and they are forwarding this get property call to
other thermal zone.

If they won't set it lockdep may report false positive deadlock for
thermal zone's mutex because of nested calls to thermal_zone_get_temp().
First is the call to thermal_zone_get_temp() of the driver's thermal
zone. Thermal core gets POWER_SUPPLY_PROP_TEMP property from this
driver. The driver then calls other thermal zone thermal_zone_get_temp()
and returns result.

Example of such driver is charger manager.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

This piece of code was added so that we return -EPROBE_DEFER when no devices are
registered. But even if class_for_each_device() returns 0, we are going to
return -EPROBE_DEFER only.

And so this code isn't required at all. Remove it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Using 'goto' statements for freeing resources on failures is a good choice as it
makes code very clean, and reduces the chances of human errors.

Though in most cases compiler may take care of this. But adding unnecessary
'goto' statements wouldn't make anything better. Code becomes less readable
actually.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

At multiple places we are doing exactly what PTR_ERR_OR_ZERO() does. And so that
routine can be reused instead of increasing lines of code here.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

The 'if' statements in power_supply_changed_work() are mostly there for taking
care of races and normally they will always evaluate to true. Optimize them for
fast execution with 'likely' statements.

Also there is need to have better comments in code to mention about the races
clearly. Get them in place.

Cc: Zoran Markovic <zrn.markovic@gmail.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

There is no need to check the value of ret.intval before returning it, as we
will be returning zero explicitly when ret.intval is zero.

So essentially we will end up returning value of ret.intval as it is. Drop the
unnecessary 'if' statements.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

We need to stop 'class_for_each_device' loop when a supply matches with the
of-node. In order to achieve this we currently return -EINVAL from
__power_supply_populate_supplied_from() on successful match.

class_for_each_device() is free to return similar errors in other cases as well
and so the choice of return value here isn't particularly great.

This commit isn't removing the Hack but making it more elegant by returning '1'
instead.

Also power_supply_find_supply_from_node() can return errors other than
-EPROBE_DEFER now if class_for_each_device() fails.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Callers of power_supply_find_supply_from_node(), i.e.
power_supply_check_supplies(), must propagate the errors returned by it instead
of returning their own.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

of_node_put() was called twice in power_supply_check_supplies() whereas a single
call will also work. Rearrange code a bit to make that feasible.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

In few routines, we need to end the do-while loop when no more "power-supplies"
are available. Currently we are doing 'continue' which will make the
'while(np)' conditional statement run again.

Skip this by doing a 'break' instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Typecast from 'void *' to any other pointer type falls under implicit typecasts
category and so doesn't require explicit typecasts. Drop them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

If power-supply's DT node doesn't have a valid "power-supplies" entry, then
power_supply_check_supplies() should return early instead of trying to allocate
memory for "supplied_from" array.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

In routine power_supply_check_supplies(), 'cnt' is counting the number of
supplies passed in "power-supplies" field of a node. The value of 'cnt' will
always be one more than the number of supplies after the do-while loop ends. And
so we need to allocate memory for 'cnt - 1' char pointers. But we are allocating
memory for 'cnt' instead.

Fix this by not over-allocating memory.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Fixes the following sparse warnings:

drivers/power/power_supply_core.c:540:5: warning:
 symbol '__power_supply_register' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NSebastian Reichel <sre@kernel.org>

Currently, all the power supply devices are registered with wakeup source,
this results in that every power_supply_changed() invocation brings
the system out of suspend-to-freeze state.

This is overkill as some device drivers, e.g. ACPI battery driver,
have the ability to check the device status and wake up the system
from sleeping only when necessary.

Thus introduce a new API which allows device to be registered
w/o wakeup source.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add method to get power supply by device tree phandle.
Signed-off-by: NSebastian Reichel <sre@debian.org>
Reviewed-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAnton Vorontsov <anton@enomsg.org>

This patch adds a notifier chain to the power_supply, this helps drivers
in other subsystem to listen to changes in power supply subsystem.

This would help to take some actions in those drivers on changing the
power supply properties. One such scenario is to increase/decrease system
performance based on the battery capacity/voltage. Another scenario is to
adjust the h/w peak current detection voltage/current thresholds based on
battery voltage/capacity. The notifier helps drivers to listen to changes
in power_suppy susbystem without polling the power_supply properties
Signed-off-by: NJenny TC <jenny.tc@intel.com>
Signed-off-by: NPali Rohár <pali.rohar@gmail.com>
Acked-by: NJenny TC <jenny.tc@intel.com>
Signed-off-by: NAnton Vorontsov <anton@enomsg.org>