linux/drivers/power/supply/ds2780_battery.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
*
* Copyright (C) 2010 Indesign, LLC
*
* Author: Clifton Barnes <cabarnes@indesign-llc.com>
*
* Based on ds2760_battery and ds2782_battery drivers
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/param.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/idr.h>
#include <linux/w1.h>
#include "../../w1/slaves/w1_ds2780.h"
/* Current unit measurement in uA for a 1 milli-ohm sense resistor */
#define DS2780_CURRENT_UNITS 1563
/* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
#define DS2780_CHARGE_UNITS 6250
/* Number of bytes in user EEPROM space */
#define DS2780_USER_EEPROM_SIZE (DS2780_EEPROM_BLOCK0_END - \
DS2780_EEPROM_BLOCK0_START + 1)
/* Number of bytes in parameter EEPROM space */
#define DS2780_PARAM_EEPROM_SIZE (DS2780_EEPROM_BLOCK1_END - \
DS2780_EEPROM_BLOCK1_START + 1)
struct ds2780_device_info {
struct device *dev;
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>
2015-03-12 15:44:11 +08:00
struct power_supply *bat;
struct power_supply_desc bat_desc;
struct device *w1_dev;
};
enum current_types {
CURRENT_NOW,
CURRENT_AVG,
};
static const char model[] = "DS2780";
static const char manufacturer[] = "Maxim/Dallas";
static inline struct ds2780_device_info *
to_ds2780_device_info(struct power_supply *psy)
{
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>
2015-03-12 15:44:11 +08:00
return power_supply_get_drvdata(psy);
}
static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
char *buf, int addr, size_t count, int io)
{
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 13:59:52 +08:00
return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
}
static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
int addr)
{
return ds2780_battery_io(dev_info, val, addr, sizeof(u8), 0);
}
static int ds2780_read16(struct ds2780_device_info *dev_info, s16 *val,
int addr)
{
int ret;
u8 raw[2];
ret = ds2780_battery_io(dev_info, raw, addr, sizeof(raw), 0);
if (ret < 0)
return ret;
*val = (raw[0] << 8) | raw[1];
return 0;
}
static inline int ds2780_read_block(struct ds2780_device_info *dev_info,
u8 *val, int addr, size_t count)
{
return ds2780_battery_io(dev_info, val, addr, count, 0);
}
static inline int ds2780_write(struct ds2780_device_info *dev_info, u8 *val,
int addr, size_t count)
{
return ds2780_battery_io(dev_info, val, addr, count, 1);
}
static inline int ds2780_store_eeprom(struct device *dev, int addr)
{
return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_COPY_DATA);
}
static inline int ds2780_recall_eeprom(struct device *dev, int addr)
{
return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_RECALL_DATA);
}
static int ds2780_save_eeprom(struct ds2780_device_info *dev_info, int reg)
{
int ret;
ret = ds2780_store_eeprom(dev_info->w1_dev, reg);
if (ret < 0)
return ret;
ret = ds2780_recall_eeprom(dev_info->w1_dev, reg);
if (ret < 0)
return ret;
return 0;
}
/* Set sense resistor value in mhos */
static int ds2780_set_sense_register(struct ds2780_device_info *dev_info,
u8 conductance)
{
int ret;
ret = ds2780_write(dev_info, &conductance,
DS2780_RSNSP_REG, sizeof(u8));
if (ret < 0)
return ret;
return ds2780_save_eeprom(dev_info, DS2780_RSNSP_REG);
}
/* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
static int ds2780_get_rsgain_register(struct ds2780_device_info *dev_info,
u16 *rsgain)
{
return ds2780_read16(dev_info, rsgain, DS2780_RSGAIN_MSB_REG);
}
/* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
static int ds2780_set_rsgain_register(struct ds2780_device_info *dev_info,
u16 rsgain)
{
int ret;
u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
ret = ds2780_write(dev_info, raw,
DS2780_RSGAIN_MSB_REG, sizeof(raw));
if (ret < 0)
return ret;
return ds2780_save_eeprom(dev_info, DS2780_RSGAIN_MSB_REG);
}
static int ds2780_get_voltage(struct ds2780_device_info *dev_info,
int *voltage_uV)
{
int ret;
s16 voltage_raw;
/*
* The voltage value is located in 10 bits across the voltage MSB
* and LSB registers in two's compliment form
* Sign bit of the voltage value is in bit 7 of the voltage MSB register
* Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
* voltage MSB register
* Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
* voltage LSB register
*/
ret = ds2780_read16(dev_info, &voltage_raw,
DS2780_VOLT_MSB_REG);
if (ret < 0)
return ret;
/*
* DS2780 reports voltage in units of 4.88mV, but the battery class
* reports in units of uV, so convert by multiplying by 4880.
*/
*voltage_uV = (voltage_raw / 32) * 4880;
return 0;
}
static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
int *temperature)
{
int ret;
s16 temperature_raw;
/*
* The temperature value is located in 10 bits across the temperature
* MSB and LSB registers in two's compliment form
* Sign bit of the temperature value is in bit 7 of the temperature
* MSB register
* Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
* temperature MSB register
* Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
* temperature LSB register
*/
ret = ds2780_read16(dev_info, &temperature_raw,
DS2780_TEMP_MSB_REG);
if (ret < 0)
return ret;
/*
* Temperature is measured in units of 0.125 degrees celcius, the
* power_supply class measures temperature in tenths of degrees
* celsius. The temperature value is stored as a 10 bit number, plus
* sign in the upper bits of a 16 bit register.
*/
*temperature = ((temperature_raw / 32) * 125) / 100;
return 0;
}
static int ds2780_get_current(struct ds2780_device_info *dev_info,
enum current_types type, int *current_uA)
{
int ret, sense_res;
s16 current_raw;
u8 sense_res_raw, reg_msb;
/*
* The units of measurement for current are dependent on the value of
* the sense resistor.
*/
ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
if (ret < 0)
return ret;
if (sense_res_raw == 0) {
dev_err(dev_info->dev, "sense resistor value is 0\n");
return -EINVAL;
}
sense_res = 1000 / sense_res_raw;
if (type == CURRENT_NOW)
reg_msb = DS2780_CURRENT_MSB_REG;
else if (type == CURRENT_AVG)
reg_msb = DS2780_IAVG_MSB_REG;
else
return -EINVAL;
/*
* The current value is located in 16 bits across the current MSB
* and LSB registers in two's compliment form
* Sign bit of the current value is in bit 7 of the current MSB register
* Bits 14 - 8 of the current value are in bits 6 - 0 of the current
* MSB register
* Bits 7 - 0 of the current value are in bits 7 - 0 of the current
* LSB register
*/
ret = ds2780_read16(dev_info, &current_raw, reg_msb);
if (ret < 0)
return ret;
*current_uA = current_raw * (DS2780_CURRENT_UNITS / sense_res);
return 0;
}
static int ds2780_get_accumulated_current(struct ds2780_device_info *dev_info,
int *accumulated_current)
{
int ret, sense_res;
s16 current_raw;
u8 sense_res_raw;
/*
* The units of measurement for accumulated current are dependent on
* the value of the sense resistor.
*/
ret = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
if (ret < 0)
return ret;
if (sense_res_raw == 0) {
dev_err(dev_info->dev, "sense resistor value is 0\n");
return -ENXIO;
}
sense_res = 1000 / sense_res_raw;
/*
* The ACR value is located in 16 bits across the ACR MSB and
* LSB registers
* Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
* MSB register
* Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
* LSB register
*/
ret = ds2780_read16(dev_info, &current_raw, DS2780_ACR_MSB_REG);
if (ret < 0)
return ret;
*accumulated_current = current_raw * (DS2780_CHARGE_UNITS / sense_res);
return 0;
}
static int ds2780_get_capacity(struct ds2780_device_info *dev_info,
int *capacity)
{
int ret;
u8 raw;
ret = ds2780_read8(dev_info, &raw, DS2780_RARC_REG);
if (ret < 0)
return ret;
*capacity = raw;
return raw;
}
static int ds2780_get_status(struct ds2780_device_info *dev_info, int *status)
{
int ret, current_uA, capacity;
ret = ds2780_get_current(dev_info, CURRENT_NOW, &current_uA);
if (ret < 0)
return ret;
ret = ds2780_get_capacity(dev_info, &capacity);
if (ret < 0)
return ret;
if (capacity == 100)
*status = POWER_SUPPLY_STATUS_FULL;
else if (current_uA == 0)
*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
else if (current_uA < 0)
*status = POWER_SUPPLY_STATUS_DISCHARGING;
else
*status = POWER_SUPPLY_STATUS_CHARGING;
return 0;
}
static int ds2780_get_charge_now(struct ds2780_device_info *dev_info,
int *charge_now)
{
int ret;
u16 charge_raw;
/*
* The RAAC value is located in 16 bits across the RAAC MSB and
* LSB registers
* Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
* MSB register
* Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
* LSB register
*/
ret = ds2780_read16(dev_info, &charge_raw, DS2780_RAAC_MSB_REG);
if (ret < 0)
return ret;
*charge_now = charge_raw * 1600;
return 0;
}
static int ds2780_get_control_register(struct ds2780_device_info *dev_info,
u8 *control_reg)
{
return ds2780_read8(dev_info, control_reg, DS2780_CONTROL_REG);
}
static int ds2780_set_control_register(struct ds2780_device_info *dev_info,
u8 control_reg)
{
int ret;
ret = ds2780_write(dev_info, &control_reg,
DS2780_CONTROL_REG, sizeof(u8));
if (ret < 0)
return ret;
return ds2780_save_eeprom(dev_info, DS2780_CONTROL_REG);
}
static int ds2780_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
int ret = 0;
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
switch (psp) {
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
ret = ds2780_get_voltage(dev_info, &val->intval);
break;
case POWER_SUPPLY_PROP_TEMP:
ret = ds2780_get_temperature(dev_info, &val->intval);
break;
case POWER_SUPPLY_PROP_MODEL_NAME:
val->strval = model;
break;
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = manufacturer;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
ret = ds2780_get_current(dev_info, CURRENT_NOW, &val->intval);
break;
case POWER_SUPPLY_PROP_CURRENT_AVG:
ret = ds2780_get_current(dev_info, CURRENT_AVG, &val->intval);
break;
case POWER_SUPPLY_PROP_STATUS:
ret = ds2780_get_status(dev_info, &val->intval);
break;
case POWER_SUPPLY_PROP_CAPACITY:
ret = ds2780_get_capacity(dev_info, &val->intval);
break;
case POWER_SUPPLY_PROP_CHARGE_COUNTER:
ret = ds2780_get_accumulated_current(dev_info, &val->intval);
break;
case POWER_SUPPLY_PROP_CHARGE_NOW:
ret = ds2780_get_charge_now(dev_info, &val->intval);
break;
default:
ret = -EINVAL;
}
return ret;
}
static enum power_supply_property ds2780_battery_props[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_MANUFACTURER,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CURRENT_AVG,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_CHARGE_NOW,
};
static ssize_t ds2780_get_pmod_enabled(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
u8 control_reg;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
/* Get power mode */
ret = ds2780_get_control_register(dev_info, &control_reg);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n",
!!(control_reg & DS2780_CONTROL_REG_PMOD));
}
static ssize_t ds2780_set_pmod_enabled(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
int ret;
u8 control_reg, new_setting;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
/* Set power mode */
ret = ds2780_get_control_register(dev_info, &control_reg);
if (ret < 0)
return ret;
ret = kstrtou8(buf, 0, &new_setting);
if (ret < 0)
return ret;
if ((new_setting != 0) && (new_setting != 1)) {
dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
return -EINVAL;
}
if (new_setting)
control_reg |= DS2780_CONTROL_REG_PMOD;
else
control_reg &= ~DS2780_CONTROL_REG_PMOD;
ret = ds2780_set_control_register(dev_info, control_reg);
if (ret < 0)
return ret;
return count;
}
static ssize_t ds2780_get_sense_resistor_value(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
u8 sense_resistor;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = ds2780_read8(dev_info, &sense_resistor, DS2780_RSNSP_REG);
if (ret < 0)
return ret;
ret = sprintf(buf, "%d\n", sense_resistor);
return ret;
}
static ssize_t ds2780_set_sense_resistor_value(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
int ret;
u8 new_setting;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = kstrtou8(buf, 0, &new_setting);
if (ret < 0)
return ret;
ret = ds2780_set_sense_register(dev_info, new_setting);
if (ret < 0)
return ret;
return count;
}
static ssize_t ds2780_get_rsgain_setting(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
u16 rsgain;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = ds2780_get_rsgain_register(dev_info, &rsgain);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", rsgain);
}
static ssize_t ds2780_set_rsgain_setting(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
int ret;
u16 new_setting;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = kstrtou16(buf, 0, &new_setting);
if (ret < 0)
return ret;
/* Gain can only be from 0 to 1.999 in steps of .001 */
if (new_setting > 1999) {
dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
return -EINVAL;
}
ret = ds2780_set_rsgain_register(dev_info, new_setting);
if (ret < 0)
return ret;
return count;
}
static ssize_t ds2780_get_pio_pin(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
u8 sfr;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = ds2780_read8(dev_info, &sfr, DS2780_SFR_REG);
if (ret < 0)
return ret;
ret = sprintf(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
return ret;
}
static ssize_t ds2780_set_pio_pin(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
int ret;
u8 new_setting;
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
ret = kstrtou8(buf, 0, &new_setting);
if (ret < 0)
return ret;
if ((new_setting != 0) && (new_setting != 1)) {
dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
return -EINVAL;
}
ret = ds2780_write(dev_info, &new_setting,
DS2780_SFR_REG, sizeof(u8));
if (ret < 0)
return ret;
return count;
}
static ssize_t ds2780_read_param_eeprom_bin(struct file *filp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
return ds2780_read_block(dev_info, buf,
DS2780_EEPROM_BLOCK1_START + off, count);
}
static ssize_t ds2780_write_param_eeprom_bin(struct file *filp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
int ret;
ret = ds2780_write(dev_info, buf,
DS2780_EEPROM_BLOCK1_START + off, count);
if (ret < 0)
return ret;
ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
if (ret < 0)
return ret;
return count;
}
static struct bin_attribute ds2780_param_eeprom_bin_attr = {
.attr = {
.name = "param_eeprom",
.mode = S_IRUGO | S_IWUSR,
},
.size = DS2780_PARAM_EEPROM_SIZE,
.read = ds2780_read_param_eeprom_bin,
.write = ds2780_write_param_eeprom_bin,
};
static ssize_t ds2780_read_user_eeprom_bin(struct file *filp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
return ds2780_read_block(dev_info, buf,
DS2780_EEPROM_BLOCK0_START + off, count);
}
static ssize_t ds2780_write_user_eeprom_bin(struct file *filp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct power_supply *psy = to_power_supply(dev);
struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);
int ret;
ret = ds2780_write(dev_info, buf,
DS2780_EEPROM_BLOCK0_START + off, count);
if (ret < 0)
return ret;
ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
if (ret < 0)
return ret;
return count;
}
static struct bin_attribute ds2780_user_eeprom_bin_attr = {
.attr = {
.name = "user_eeprom",
.mode = S_IRUGO | S_IWUSR,
},
.size = DS2780_USER_EEPROM_SIZE,
.read = ds2780_read_user_eeprom_bin,
.write = ds2780_write_user_eeprom_bin,
};
static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
ds2780_set_pmod_enabled);
static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
ds2780_set_rsgain_setting);
static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
ds2780_set_pio_pin);
static struct attribute *ds2780_sysfs_attrs[] = {
&dev_attr_pmod_enabled.attr,
&dev_attr_sense_resistor_value.attr,
&dev_attr_rsgain_setting.attr,
&dev_attr_pio_pin.attr,
NULL
};
static struct bin_attribute *ds2780_sysfs_bin_attrs[] = {
&ds2780_param_eeprom_bin_attr,
&ds2780_user_eeprom_bin_attr,
NULL
};
static const struct attribute_group ds2780_sysfs_group = {
.attrs = ds2780_sysfs_attrs,
.bin_attrs = ds2780_sysfs_bin_attrs,
};
static const struct attribute_group *ds2780_sysfs_groups[] = {
&ds2780_sysfs_group,
NULL,
};
static int ds2780_battery_probe(struct platform_device *pdev)
{
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>
2015-03-12 15:44:11 +08:00
struct power_supply_config psy_cfg = {};
struct ds2780_device_info *dev_info;
dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
if (!dev_info)
return -ENOMEM;
platform_set_drvdata(pdev, dev_info);
dev_info->dev = &pdev->dev;
dev_info->w1_dev = pdev->dev.parent;
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>
2015-03-12 15:44:11 +08:00
dev_info->bat_desc.name = dev_name(&pdev->dev);
dev_info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
dev_info->bat_desc.properties = ds2780_battery_props;
dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2780_battery_props);
dev_info->bat_desc.get_property = ds2780_battery_get_property;
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>
2015-03-12 15:44:11 +08:00
psy_cfg.drv_data = dev_info;
psy_cfg.attr_grp = ds2780_sysfs_groups;
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>
2015-03-12 15:44:11 +08:00
dev_info->bat = devm_power_supply_register(&pdev->dev,
&dev_info->bat_desc,
&psy_cfg);
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>
2015-03-12 15:44:11 +08:00
if (IS_ERR(dev_info->bat)) {
dev_err(dev_info->dev, "failed to register battery\n");
return PTR_ERR(dev_info->bat);
}
return 0;
}
static struct platform_driver ds2780_battery_driver = {
.driver = {
.name = "ds2780-battery",
},
.probe = ds2780_battery_probe,
};
module_platform_driver(ds2780_battery_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC driver");
MODULE_ALIAS("platform:ds2780-battery");