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297d716f62
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>
134 lines
4.2 KiB
C
134 lines
4.2 KiB
C
/*
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* supply.h -- Power Supply Driver for Wolfson WM8350 PMIC
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*
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* Copyright 2007 Wolfson Microelectronics PLC
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#ifndef __LINUX_MFD_WM8350_SUPPLY_H_
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#define __LINUX_MFD_WM8350_SUPPLY_H_
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#include <linux/mutex.h>
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#include <linux/power_supply.h>
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/*
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* Charger registers
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*/
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#define WM8350_BATTERY_CHARGER_CONTROL_1 0xA8
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#define WM8350_BATTERY_CHARGER_CONTROL_2 0xA9
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#define WM8350_BATTERY_CHARGER_CONTROL_3 0xAA
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/*
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* R168 (0xA8) - Battery Charger Control 1
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*/
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#define WM8350_CHG_ENA_R168 0x8000
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#define WM8350_CHG_THR 0x2000
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#define WM8350_CHG_EOC_SEL_MASK 0x1C00
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#define WM8350_CHG_TRICKLE_TEMP_CHOKE 0x0200
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#define WM8350_CHG_TRICKLE_USB_CHOKE 0x0100
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#define WM8350_CHG_RECOVER_T 0x0080
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#define WM8350_CHG_END_ACT 0x0040
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#define WM8350_CHG_FAST 0x0020
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#define WM8350_CHG_FAST_USB_THROTTLE 0x0010
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#define WM8350_CHG_NTC_MON 0x0008
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#define WM8350_CHG_BATT_HOT_MON 0x0004
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#define WM8350_CHG_BATT_COLD_MON 0x0002
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#define WM8350_CHG_CHIP_TEMP_MON 0x0001
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/*
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* R169 (0xA9) - Battery Charger Control 2
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*/
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#define WM8350_CHG_ACTIVE 0x8000
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#define WM8350_CHG_PAUSE 0x4000
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#define WM8350_CHG_STS_MASK 0x3000
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#define WM8350_CHG_TIME_MASK 0x0F00
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#define WM8350_CHG_MASK_WALL_FB 0x0080
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#define WM8350_CHG_TRICKLE_SEL 0x0040
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#define WM8350_CHG_VSEL_MASK 0x0030
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#define WM8350_CHG_ISEL_MASK 0x000F
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#define WM8350_CHG_STS_OFF 0x0000
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#define WM8350_CHG_STS_TRICKLE 0x1000
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#define WM8350_CHG_STS_FAST 0x2000
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/*
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* R170 (0xAA) - Battery Charger Control 3
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*/
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#define WM8350_CHG_THROTTLE_T_MASK 0x0060
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#define WM8350_CHG_SMART 0x0010
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#define WM8350_CHG_TIMER_ADJT_MASK 0x000F
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/*
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* Charger Interrupts
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*/
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#define WM8350_IRQ_CHG_BAT_HOT 0
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#define WM8350_IRQ_CHG_BAT_COLD 1
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#define WM8350_IRQ_CHG_BAT_FAIL 2
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#define WM8350_IRQ_CHG_TO 3
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#define WM8350_IRQ_CHG_END 4
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#define WM8350_IRQ_CHG_START 5
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#define WM8350_IRQ_CHG_FAST_RDY 6
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#define WM8350_IRQ_CHG_VBATT_LT_3P9 10
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#define WM8350_IRQ_CHG_VBATT_LT_3P1 11
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#define WM8350_IRQ_CHG_VBATT_LT_2P85 12
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/*
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* Charger Policy
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*/
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#define WM8350_CHG_TRICKLE_50mA (0 << 6)
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#define WM8350_CHG_TRICKLE_100mA (1 << 6)
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#define WM8350_CHG_4_05V (0 << 4)
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#define WM8350_CHG_4_10V (1 << 4)
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#define WM8350_CHG_4_15V (2 << 4)
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#define WM8350_CHG_4_20V (3 << 4)
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#define WM8350_CHG_FAST_LIMIT_mA(x) ((x / 50) & 0xf)
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#define WM8350_CHG_EOC_mA(x) (((x - 10) & 0x7) << 10)
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#define WM8350_CHG_TRICKLE_3_1V (0 << 13)
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#define WM8350_CHG_TRICKLE_3_9V (1 << 13)
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/*
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* Supply Registers.
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*/
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#define WM8350_USB_VOLTAGE_READBACK 0x9C
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#define WM8350_LINE_VOLTAGE_READBACK 0x9D
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#define WM8350_BATT_VOLTAGE_READBACK 0x9E
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/*
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* Supply Interrupts.
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*/
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#define WM8350_IRQ_USB_LIMIT 15
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#define WM8350_IRQ_EXT_USB_FB 36
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#define WM8350_IRQ_EXT_WALL_FB 37
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#define WM8350_IRQ_EXT_BAT_FB 38
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/*
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* Policy to control charger state machine.
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*/
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struct wm8350_charger_policy {
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/* charger state machine policy - set in machine driver */
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int eoc_mA; /* end of charge current (mA) */
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int charge_mV; /* charge voltage */
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int fast_limit_mA; /* fast charge current limit */
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int fast_limit_USB_mA; /* USB fast charge current limit */
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int charge_timeout; /* charge timeout (mins) */
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int trickle_start_mV; /* trickle charge starts at mV */
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int trickle_charge_mA; /* trickle charge current */
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int trickle_charge_USB_mA; /* USB trickle charge current */
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};
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struct wm8350_power {
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struct platform_device *pdev;
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struct power_supply *battery;
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struct power_supply *usb;
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struct power_supply *ac;
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struct wm8350_charger_policy *policy;
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int rev_g_coeff;
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};
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#endif
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