linux-toradex.git/drivers/power/power_supply_sysfs.c, branch v4.7-rc4

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_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: Use wrappers to avoid races when registering power supply

2015-05-23T18:06:19+00:00

Use wrappers over get_property() and set_property() internally in power
supply and for sysfs interface. The wrappers provide safe access if
power supply is not yet registered or t is being destroyed.

In case of syfs the theoretical race could happen between ending of
driver's probe and parallel sysfs access:
some_driver_probe()                    userspace
====================================   ===========================
  drv->psy = power_supply_register()
    device_add()
      sysfs entries are created
    atomic_inc(&psy->use_cnt);
                                       store on sysfs attributes
                                         drv->set_property()
                                           dereference of drv->psy
  drv->psy = returned psy;

For leds the race could happen between power supply being destroyed and
ongoing power_supply_changed_work().

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Sebastian Reichel

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: sysfs: Use power_supply_*() API for accessing function attrs

2015-03-13T22:15:48+00:00

Replace direct calls to power supply function attributes with wrappers.
Wrappers provide safe access in case of unregistering the power
supply (e.g. by removing the driver). Replace:
 - get_property -> power_supply_get_property
 - set_property -> power_supply_set_property
 - property_is_writeable -> power_supply_property_is_writeable

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

power-supply: Check for failures only when we can fail

2014-09-16T09:01:37+00:00

In power_supply_show_property() routine, we call ->get_property() conditionally
and should check for failure in that case only. There is no point comparing
'ret' for errors when 'ret' is surely zero.

Signed-off-by: Viresh Kumar 
Signed-off-by: Sebastian Reichel

power_supply: Add boot and calibration attributes

2014-09-06T19:05:04+00:00

Usually PMIC's come with coulomb counting mechanism which can be
used to implement a Fuel Gauginig solution in Software itself.
One of key input to these SW Fuel Gauge solutioons is the boot up
parameters like boot voltage and boot current.

This patch adds the VOLTAGE_BOOT and CURRENT_BOOT power supply attributes
to report bootup voltage and current.

This patch also adds CALIBRATE power supply attribute which useful is
for calibrating the battery/coulomb counter.

Signed-off-by: Ramakrishna Pallala 
Signed-off-by: Sebastian Reichel

power_supply: Add inlmt,iterm, min/max temp props

2014-07-18T21:40:23+00:00

Add new power supply properties for input current, charge termination
current, min and max temperature

POWER_SUPPLY_PROP_TEMP_MIN - minimum operatable temperature
POWER_SUPPLY_PROP_TEMP_MAX - maximum operatable temperature

POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT - input current limit programmed
by charger. Indicates the input current for a charging source.

POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT - Charge termination current used
to detect the end of charge condition

Signed-off-by: Jenny TC 
Acked-by: Pavel Machek 
Signed-off-by: Sebastian Reichel

power_supply: Replace strict_strtol() with kstrtol()

2013-08-09T21:49:49+00:00

The usage of strict_strtol() is not preferred, because strict_strtol() is
obsolete. Thus, kstrtol() should be used.

Signed-off-by: Jingoo Han 
Signed-off-by: Anton Vorontsov

power_supply: Add watchdog and safety timer expiries under PROP_HEALTH_*

2013-01-06T02:51:18+00:00

As most of the charger chips come with two kinds of safety features
related to timing:

1. Watchdog Timer (interms of seconds/mins)
2. Safety Timer (interms of hours)

This patch adds these to fault causes in POWER_SUPPLY_PROP_HEALTH_* enums
so that whenever there is either watchdog timeout or safety timer timeout
driver could notify the user space accurately about the fault and will
also be helpful for debug.

Signed-off-by: Ramakrishna Pallala 
Signed-off-by: Anton Vorontsov