linux/drivers/power/ipaq_micro_battery.c
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

317 lines
7.9 KiB
C

/*
* 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.
*
* h3xxx atmel micro companion support, battery subdevice
* based on previous kernel 2.4 version
* Author : Alessandro Gardich <gremlin@gremlin.it>
* Author : Linus Walleij <linus.walleij@linaro.org>
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mfd/ipaq-micro.h>
#include <linux/power_supply.h>
#include <linux/workqueue.h>
#define BATT_PERIOD 100000 /* 100 seconds in milliseconds */
#define MICRO_BATT_CHEM_ALKALINE 0x01
#define MICRO_BATT_CHEM_NICD 0x02
#define MICRO_BATT_CHEM_NIMH 0x03
#define MICRO_BATT_CHEM_LION 0x04
#define MICRO_BATT_CHEM_LIPOLY 0x05
#define MICRO_BATT_CHEM_NOT_INSTALLED 0x06
#define MICRO_BATT_CHEM_UNKNOWN 0xff
#define MICRO_BATT_STATUS_HIGH 0x01
#define MICRO_BATT_STATUS_LOW 0x02
#define MICRO_BATT_STATUS_CRITICAL 0x04
#define MICRO_BATT_STATUS_CHARGING 0x08
#define MICRO_BATT_STATUS_CHARGEMAIN 0x10
#define MICRO_BATT_STATUS_DEAD 0x20 /* Battery will not charge */
#define MICRO_BATT_STATUS_NOTINSTALLED 0x20 /* For expansion pack batteries */
#define MICRO_BATT_STATUS_FULL 0x40 /* Battery fully charged */
#define MICRO_BATT_STATUS_NOBATTERY 0x80
#define MICRO_BATT_STATUS_UNKNOWN 0xff
struct micro_battery {
struct ipaq_micro *micro;
struct workqueue_struct *wq;
struct delayed_work update;
u8 ac;
u8 chemistry;
unsigned int voltage;
u16 temperature;
u8 flag;
};
static void micro_battery_work(struct work_struct *work)
{
struct micro_battery *mb = container_of(work,
struct micro_battery, update.work);
struct ipaq_micro_msg msg_battery = {
.id = MSG_BATTERY,
};
struct ipaq_micro_msg msg_sensor = {
.id = MSG_THERMAL_SENSOR,
};
/* First send battery message */
ipaq_micro_tx_msg_sync(mb->micro, &msg_battery);
if (msg_battery.rx_len < 4)
pr_info("ERROR");
/*
* Returned message format:
* byte 0: 0x00 = Not plugged in
* 0x01 = AC adapter plugged in
* byte 1: chemistry
* byte 2: voltage LSB
* byte 3: voltage MSB
* byte 4: flags
* byte 5-9: same for battery 2
*/
mb->ac = msg_battery.rx_data[0];
mb->chemistry = msg_battery.rx_data[1];
mb->voltage = ((((unsigned short)msg_battery.rx_data[3] << 8) +
msg_battery.rx_data[2]) * 5000L) * 1000 / 1024;
mb->flag = msg_battery.rx_data[4];
if (msg_battery.rx_len == 9)
pr_debug("second battery ignored\n");
/* Then read the sensor */
ipaq_micro_tx_msg_sync(mb->micro, &msg_sensor);
mb->temperature = msg_sensor.rx_data[1] << 8 | msg_sensor.rx_data[0];
queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
}
static int get_capacity(struct power_supply *b)
{
struct micro_battery *mb = dev_get_drvdata(b->dev.parent);
switch (mb->flag & 0x07) {
case MICRO_BATT_STATUS_HIGH:
return 100;
break;
case MICRO_BATT_STATUS_LOW:
return 50;
break;
case MICRO_BATT_STATUS_CRITICAL:
return 5;
break;
default:
break;
}
return 0;
}
static int get_status(struct power_supply *b)
{
struct micro_battery *mb = dev_get_drvdata(b->dev.parent);
if (mb->flag == MICRO_BATT_STATUS_UNKNOWN)
return POWER_SUPPLY_STATUS_UNKNOWN;
if (mb->flag & MICRO_BATT_STATUS_FULL)
return POWER_SUPPLY_STATUS_FULL;
if ((mb->flag & MICRO_BATT_STATUS_CHARGING) ||
(mb->flag & MICRO_BATT_STATUS_CHARGEMAIN))
return POWER_SUPPLY_STATUS_CHARGING;
return POWER_SUPPLY_STATUS_DISCHARGING;
}
static int micro_batt_get_property(struct power_supply *b,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct micro_battery *mb = dev_get_drvdata(b->dev.parent);
switch (psp) {
case POWER_SUPPLY_PROP_TECHNOLOGY:
switch (mb->chemistry) {
case MICRO_BATT_CHEM_NICD:
val->intval = POWER_SUPPLY_TECHNOLOGY_NiCd;
break;
case MICRO_BATT_CHEM_NIMH:
val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
break;
case MICRO_BATT_CHEM_LION:
val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
break;
case MICRO_BATT_CHEM_LIPOLY:
val->intval = POWER_SUPPLY_TECHNOLOGY_LIPO;
break;
default:
val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
break;
};
break;
case POWER_SUPPLY_PROP_STATUS:
val->intval = get_status(b);
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
val->intval = 4700000;
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = get_capacity(b);
break;
case POWER_SUPPLY_PROP_TEMP:
val->intval = mb->temperature;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = mb->voltage;
break;
default:
return -EINVAL;
};
return 0;
}
static int micro_ac_get_property(struct power_supply *b,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct micro_battery *mb = dev_get_drvdata(b->dev.parent);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = mb->ac;
break;
default:
return -EINVAL;
};
return 0;
}
static enum power_supply_property micro_batt_power_props[] = {
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
};
static const struct power_supply_desc micro_batt_power_desc = {
.name = "main-battery",
.type = POWER_SUPPLY_TYPE_BATTERY,
.properties = micro_batt_power_props,
.num_properties = ARRAY_SIZE(micro_batt_power_props),
.get_property = micro_batt_get_property,
.use_for_apm = 1,
};
static enum power_supply_property micro_ac_power_props[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static const struct power_supply_desc micro_ac_power_desc = {
.name = "ac",
.type = POWER_SUPPLY_TYPE_MAINS,
.properties = micro_ac_power_props,
.num_properties = ARRAY_SIZE(micro_ac_power_props),
.get_property = micro_ac_get_property,
};
static struct power_supply *micro_batt_power, *micro_ac_power;
static int micro_batt_probe(struct platform_device *pdev)
{
struct micro_battery *mb;
int ret;
mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
if (!mb)
return -ENOMEM;
mb->micro = dev_get_drvdata(pdev->dev.parent);
mb->wq = create_singlethread_workqueue("ipaq-battery-wq");
if (!mb->wq)
return -ENOMEM;
INIT_DELAYED_WORK(&mb->update, micro_battery_work);
platform_set_drvdata(pdev, mb);
queue_delayed_work(mb->wq, &mb->update, 1);
micro_batt_power = power_supply_register(&pdev->dev,
&micro_batt_power_desc, NULL);
if (IS_ERR(micro_batt_power)) {
ret = PTR_ERR(micro_batt_power);
goto batt_err;
}
micro_ac_power = power_supply_register(&pdev->dev,
&micro_ac_power_desc, NULL);
if (IS_ERR(micro_ac_power)) {
ret = PTR_ERR(micro_ac_power);
goto ac_err;
}
dev_info(&pdev->dev, "iPAQ micro battery driver\n");
return 0;
ac_err:
power_supply_unregister(micro_ac_power);
batt_err:
cancel_delayed_work_sync(&mb->update);
destroy_workqueue(mb->wq);
return ret;
}
static int micro_batt_remove(struct platform_device *pdev)
{
struct micro_battery *mb = platform_get_drvdata(pdev);
power_supply_unregister(micro_ac_power);
power_supply_unregister(micro_batt_power);
cancel_delayed_work_sync(&mb->update);
destroy_workqueue(mb->wq);
return 0;
}
static int micro_batt_suspend(struct device *dev)
{
struct micro_battery *mb = dev_get_drvdata(dev);
cancel_delayed_work_sync(&mb->update);
return 0;
}
static int micro_batt_resume(struct device *dev)
{
struct micro_battery *mb = dev_get_drvdata(dev);
queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
return 0;
}
static const struct dev_pm_ops micro_batt_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(micro_batt_suspend, micro_batt_resume)
};
static struct platform_driver micro_batt_device_driver = {
.driver = {
.name = "ipaq-micro-battery",
.pm = &micro_batt_dev_pm_ops,
},
.probe = micro_batt_probe,
.remove = micro_batt_remove,
};
module_platform_driver(micro_batt_device_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("driver for iPAQ Atmel micro battery");
MODULE_ALIAS("platform:battery-ipaq-micro");