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>
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>
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 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>
Remove caching of charging and battery states in driver's state
container because the cached value was not used later.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Remove hard-coded values for:
- Fast Charge current,
- End Of Charge current,
- Fast Charge timer,
- Overvoltage Protection Threshold,
- Battery Constant Voltage,
and use DTS or sysfs to configure them. This allows using the max14577 charger
driver with different batteries.
Now the charger driver requires valid configuration data from DTS. In
case of wrong configuration data it fails during probe.
The fast charge timer is configured through sysfs entry.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Add support for MAX77836 charger to the max14577 driver. The MAX77836
charger is almost the same as 14577 model except:
- No dead-battery detection;
- Support for special charger (like in MAX77693);
- Support for DX over-voltage protection (like in MAX77693);
- Lower values of charging current (two times lower current for
slow/fast charge, much lower EOC current);
- Slightly different values in ChgTyp field of STATUS2 register. On
MAX14577 0x6 is reserved and 0x7 dead battery. On the MAX77836 the
0x6 means special charger and 0x7 is reserved. Regardless of these
differences the driver maps them to one enum max14577_muic_charger_type.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
MAX14577 chip is a multi-function device which includes MUIC, charger and
voltage regulator. The driver is located in drivers/mfd.
This patch supports battery charging control of MAX14577 chip and provides
power supply class information to userspace.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
