linux-toradex.git/drivers/power/ds2782_battery.c, branch v4.2.6

power_supply: Change ownership from driver to core

2015-03-13T22:15:51+00:00

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 : []    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] [] (charger_get_property) from [] (power_supply_show_property+0x48/0x20c)
[   55.939286] [] (power_supply_show_property) from [] (dev_attr_show+0x1c/0x48)
[   55.948130] [] (dev_attr_show) from [] (sysfs_kf_seq_show+0x84/0x104)
[   55.956298] [] (sysfs_kf_seq_show) from [] (kernfs_seq_show+0x24/0x28)
[   55.964536] [] (kernfs_seq_show) from [] (seq_read+0x1b0/0x484)
[   55.972172] [] (seq_read) from [] (__vfs_read+0x18/0x4c)
[   55.979188] [] (__vfs_read) from [] (vfs_read+0x7c/0x100)
[   55.986304] [] (vfs_read) from [] (SyS_read+0x40/0x8c)
[   55.993164] [] (SyS_read) from [] (ret_fast_syscall+0x0/0x48)
[   56.000626] Code: bad PC value
[   56.011652] ---[ end trace 7b64343fbdae8ef1 ]---

Signed-off-by: Krzysztof Kozlowski 
Reviewed-by: Bartlomiej Zolnierkiewicz 

[for the nvec part]
Reviewed-by: Marc Dietrich 

[for compal-laptop.c]
Acked-by: Darren Hart 

[for the mfd part]
Acked-by: Lee Jones 

[for the hid part]
Acked-by: Jiri Kosina 

[for the acpi part]
Acked-by: Rafael J. Wysocki 

Signed-off-by: Sebastian Reichel

power_supply: Move run-time configuration to separate structure

2015-03-13T22:15:12+00:00

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: Krzysztof Kozlowski 
Reviewed-by: Bartlomiej Zolnierkiewicz 
Acked-by: Pavel Machek 

[for the nvec part]
Reviewed-by: Marc Dietrich 

[for drivers/platform/x86/compal-laptop.c]
Reviewed-by: Darren Hart 

[for drivers/hid/*]
Reviewed-by: Jiri Kosina 

Signed-off-by: Sebastian Reichel

power: ds2782_battery: Simplify the PM hooks

2014-11-17T02:07:11+00:00

The SIMPLE_DEV_PM_OPS() macro already takes care of the CONFIG_PM_SLEEP=n case,
so we can simplify the code a little bit.

Signed-off-by: Fabio Estevam 
Signed-off-by: Sebastian Reichel

power: ds2782_battery: Typo in comment

2014-01-25T11:24:15+00:00

Change missleading comment to actual shift value provided by the chip.

Signed-off-by: Matthias Brugger

ds2782_battery: Use dev_pm_ops

2013-04-01T06:01:10+00:00

Use dev_pm_ops instead of the deprecated legacy suspend/resume callbacks.

Cc: Evgeny Romanov 
Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Anton Vorontsov

power: convert to idr_alloc()

2013-02-28T03:10:18+00:00

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo 
Acked-by: Anton Vorontsov 
Cc: David Woodhouse 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ds2782_battery: Add power_supply_changed() calls for proper uevent support

2013-02-03T03:07:34+00:00

This patch affects on Android battery indicator. Battery driver should
send uevent message when battery status changes in order to get Android
battery level dynamically updated. Delayed work was added to periodically
check battery status and capacity.

Signed-off-by: Evgeny Romanov 
Signed-off-by: Anton Vorontsov

ds2782_battery: Fix signedness bug in ds278x_read_reg16()

2012-11-18T22:46:39+00:00

We need to check for negative values before doing the swab16() for the
error handling to work.

Signed-off-by: Dan Carpenter 
Signed-off-by: Anton Vorontsov

power_supply: Convert i2c drivers to module_i2c_driver

2012-03-26T16:41:22+00:00

Factor out some boilerplate code for i2c driver registration
into module_i2c_driver.

Signed-off-by: Axel Lin 
Cc: Woogyom Kim 
Cc: Daniel Jeong 
Cc: Minkyu Kang 
Cc: Peter Edwards 
Acked-by: Milo(Woogyom) Kim 
Acked-by: Rhyland Klein 
Acked-by: Ryan Mallon 
Signed-off-by: Anton Vorontsov

Change Ryan Mallon's email address across the kernel

2011-06-16T09:22:05+00:00

I no longer work at Bluewater Systems. Update my email address accordingly. I
have deleted my email address from C files rather than change it. This
was suggested by several people, since the commit from my new email
address will cause scripts/get_maintainer.pl to function properly. I
have not added the .mailmap entry as suggested by Joe because I think
it is no longer necessary if I touch all the files which had my name
in them.

Signed-off-by: Ryan Mallon 
Cc: Andre Renaud 
Cc: H Hartley Sweeten 
Cc: Russell King 
Cc: Nicolas Ferre 
Cc: Andrew Victor 
Cc: David Woodhouse 
Cc: Anton Vorontsov 
Cc: Paul Mundt 
Cc: Liam Girdwood 
Cc: Mark Brown 
Cc: Alan Cox 
Cc: Joe Perches 
Cc: Jesper Juhl 
Cc: Andrew Morton 
Cc: trivial@kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Jesper Juhl 
Signed-off-by: Jiri Kosina