alistair23-linux/include/linux/power/charger-manager.h
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

260 lines
7.7 KiB
C

/*
* Copyright (C) 2011 Samsung Electronics Co., Ltd.
* MyungJoo.Ham <myungjoo.ham@samsung.com>
*
* Charger Manager.
* This framework enables to control and multiple chargers and to
* monitor charging even in the context of suspend-to-RAM with
* an interface combining the chargers.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
**/
#ifndef _CHARGER_MANAGER_H
#define _CHARGER_MANAGER_H
#include <linux/power_supply.h>
#include <linux/extcon.h>
#include <linux/alarmtimer.h>
enum data_source {
CM_BATTERY_PRESENT,
CM_NO_BATTERY,
CM_FUEL_GAUGE,
CM_CHARGER_STAT,
};
enum polling_modes {
CM_POLL_DISABLE = 0,
CM_POLL_ALWAYS,
CM_POLL_EXTERNAL_POWER_ONLY,
CM_POLL_CHARGING_ONLY,
};
enum cm_event_types {
CM_EVENT_UNKNOWN = 0,
CM_EVENT_BATT_FULL,
CM_EVENT_BATT_IN,
CM_EVENT_BATT_OUT,
CM_EVENT_BATT_OVERHEAT,
CM_EVENT_BATT_COLD,
CM_EVENT_EXT_PWR_IN_OUT,
CM_EVENT_CHG_START_STOP,
CM_EVENT_OTHERS,
};
/**
* struct charger_cable
* @extcon_name: the name of extcon device.
* @name: the name of charger cable(external connector).
* @extcon_dev: the extcon device.
* @wq: the workqueue to control charger according to the state of
* charger cable. If charger cable is attached, enable charger.
* But if charger cable is detached, disable charger.
* @nb: the notifier block to receive changed state from EXTCON
* (External Connector) when charger cable is attached/detached.
* @attached: the state of charger cable.
* true: the charger cable is attached
* false: the charger cable is detached
* @charger: the instance of struct charger_regulator.
* @cm: the Charger Manager representing the battery.
*/
struct charger_cable {
const char *extcon_name;
const char *name;
/* The charger-manager use Exton framework*/
struct extcon_specific_cable_nb extcon_dev;
struct work_struct wq;
struct notifier_block nb;
/* The state of charger cable */
bool attached;
struct charger_regulator *charger;
/*
* Set min/max current of regulator to protect over-current issue
* according to a kind of charger cable when cable is attached.
*/
int min_uA;
int max_uA;
struct charger_manager *cm;
};
/**
* struct charger_regulator
* @regulator_name: the name of regulator for using charger.
* @consumer: the regulator consumer for the charger.
* @externally_control:
* Set if the charger-manager cannot control charger,
* the charger will be maintained with disabled state.
* @cables:
* the array of charger cables to enable/disable charger
* and set current limit according to constratint data of
* struct charger_cable if only charger cable included
* in the array of charger cables is attached/detached.
* @num_cables: the number of charger cables.
* @attr_g: Attribute group for the charger(regulator)
* @attr_name: "name" sysfs entry
* @attr_state: "state" sysfs entry
* @attr_externally_control: "externally_control" sysfs entry
* @attrs: Arrays pointing to attr_name/state/externally_control for attr_g
*/
struct charger_regulator {
/* The name of regulator for charging */
const char *regulator_name;
struct regulator *consumer;
/* charger never on when system is on */
int externally_control;
/*
* Store constraint information related to current limit,
* each cable have different condition for charging.
*/
struct charger_cable *cables;
int num_cables;
struct attribute_group attr_g;
struct device_attribute attr_name;
struct device_attribute attr_state;
struct device_attribute attr_externally_control;
struct attribute *attrs[4];
struct charger_manager *cm;
};
/**
* struct charger_desc
* @psy_name: the name of power-supply-class for charger manager
* @polling_mode:
* Determine which polling mode will be used
* @fullbatt_vchkdrop_ms:
* @fullbatt_vchkdrop_uV:
* Check voltage drop after the battery is fully charged.
* If it has dropped more than fullbatt_vchkdrop_uV after
* fullbatt_vchkdrop_ms, CM will restart charging.
* @fullbatt_uV: voltage in microvolt
* If VBATT >= fullbatt_uV, it is assumed to be full.
* @fullbatt_soc: state of Charge in %
* If state of Charge >= fullbatt_soc, it is assumed to be full.
* @fullbatt_full_capacity: full capacity measure
* If full capacity of battery >= fullbatt_full_capacity,
* it is assumed to be full.
* @polling_interval_ms: interval in millisecond at which
* charger manager will monitor battery health
* @battery_present:
* Specify where information for existance of battery can be obtained
* @psy_charger_stat: the names of power-supply for chargers
* @num_charger_regulator: the number of entries in charger_regulators
* @charger_regulators: array of charger regulators
* @psy_fuel_gauge: the name of power-supply for fuel gauge
* @thermal_zone : the name of thermal zone for battery
* @temp_min : Minimum battery temperature for charging.
* @temp_max : Maximum battery temperature for charging.
* @temp_diff : Temperature diffential to restart charging.
* @measure_battery_temp:
* true: measure battery temperature
* false: measure ambient temperature
* @charging_max_duration_ms: Maximum possible duration for charging
* If whole charging duration exceed 'charging_max_duration_ms',
* cm stop charging.
* @discharging_max_duration_ms:
* Maximum possible duration for discharging with charger cable
* after full-batt. If discharging duration exceed 'discharging
* max_duration_ms', cm start charging.
*/
struct charger_desc {
const char *psy_name;
enum polling_modes polling_mode;
unsigned int polling_interval_ms;
unsigned int fullbatt_vchkdrop_ms;
unsigned int fullbatt_vchkdrop_uV;
unsigned int fullbatt_uV;
unsigned int fullbatt_soc;
unsigned int fullbatt_full_capacity;
enum data_source battery_present;
const char **psy_charger_stat;
int num_charger_regulators;
struct charger_regulator *charger_regulators;
const char *psy_fuel_gauge;
const char *thermal_zone;
int temp_min;
int temp_max;
int temp_diff;
bool measure_battery_temp;
u32 charging_max_duration_ms;
u32 discharging_max_duration_ms;
};
#define PSY_NAME_MAX 30
/**
* struct charger_manager
* @entry: entry for list
* @dev: device pointer
* @desc: instance of charger_desc
* @fuel_gauge: power_supply for fuel gauge
* @charger_stat: array of power_supply for chargers
* @tzd_batt : thermal zone device for battery
* @charger_enabled: the state of charger
* @fullbatt_vchk_jiffies_at:
* jiffies at the time full battery check will occur.
* @fullbatt_vchk_work: work queue for full battery check
* @emergency_stop:
* When setting true, stop charging
* @psy_name_buf: the name of power-supply-class for charger manager
* @charger_psy: power_supply for charger manager
* @status_save_ext_pwr_inserted:
* saved status of external power before entering suspend-to-RAM
* @status_save_batt:
* saved status of battery before entering suspend-to-RAM
* @charging_start_time: saved start time of enabling charging
* @charging_end_time: saved end time of disabling charging
*/
struct charger_manager {
struct list_head entry;
struct device *dev;
struct charger_desc *desc;
#ifdef CONFIG_THERMAL
struct thermal_zone_device *tzd_batt;
#endif
bool charger_enabled;
unsigned long fullbatt_vchk_jiffies_at;
struct delayed_work fullbatt_vchk_work;
int emergency_stop;
char psy_name_buf[PSY_NAME_MAX + 1];
struct power_supply_desc charger_psy_desc;
struct power_supply *charger_psy;
u64 charging_start_time;
u64 charging_end_time;
};
#ifdef CONFIG_CHARGER_MANAGER
extern void cm_notify_event(struct power_supply *psy,
enum cm_event_types type, char *msg);
#else
static inline void cm_notify_event(struct power_supply *psy,
enum cm_event_types type, char *msg) { }
#endif
#endif /* _CHARGER_MANAGER_H */