Commit Graph

7 Commits

Author SHA1 Message Date
Krzysztof Kozlowski
61b305cd2a drivers: max77693: Move state container to common header
This prepares for merging some of the drivers between max77693 and
max77843 so the child MFD driver can be attached to any parent MFD main
driver.

Move the state container to common header file. Additionally add
consistent 'i2c' prefixes to its members (of 'struct i2c_client' type).

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-16 21:39:30 +01:00
Krzysztof Kozlowski
297d716f62 power_supply: Change ownership from driver to core
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: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

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

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

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

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

[for the acpi part]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-03-13 23:15:51 +01:00
Krzysztof Kozlowski
2dc9215d7c power_supply: Move run-time configuration to separate structure
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 <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>

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

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

[for drivers/hid/*]
Reviewed-by: Jiri Kosina <jkosina@suse.cz>

Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-03-13 23:15:12 +01:00
Krzysztof Kozlowski
1ed522b390 power_supply: max77693: Properly handle error conditions
Re-work and fix handling of errors when retrieving power supply
properties:

1. Return errno values directly from get_property() instead of storing
   'unknown' as intval for given property.

2. Handle regmap_read() errors when getting 'online' and 'present'
   proprties and return errno code. Previously the regmap_read() return
   code was ignored so an uninitialized value from the stack could be
   used for calculating the property.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-02-25 21:45:46 +01:00
kbuild test robot
a7c45b6c28 power: max77693: fix platform_no_drv_owner.cocci warnings
drivers/power/max77693_charger.c:747:3-8: No need to set .owner here. The core will do it.

 Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-21 14:02:41 +01:00
kbuild test robot
5b40b3e6f1 power: max77693: fix simple_return.cocci warnings
drivers/power/max77693_charger.c:615:1-4: WARNING: end returns can be simpified

 Simplify a trivial if-return sequence.  Possibly combine with a
 preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci

CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-21 14:02:30 +01:00
Krzysztof Kozlowski
87c2d90678 power: max77693: Add charger driver for Maxim 77693
Add new driver for Maxim 77693 switch-mode charger (part of max77693
MFD driver) providing power supply class information to userspace.

The charger has +20V tolerant input. Current input can be set from 0 to
2.58 A. The charger can deliver up to 2.1 A to the battery or 3.5 A to
the system (when supplying additional current from battery to system).

The driver is configured through DTS (battery and system related
settings) and sysfs entries (timers and top-off charging threshold).

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-01-20 14:04:12 +01:00