linux/drivers/power/jz4740-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

426 lines
10 KiB
C

/*
* Battery measurement code for Ingenic JZ SOC.
*
* Copyright (C) 2009 Jiejing Zhang <kzjeef@gmail.com>
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
*
* based on tosa_battery.c
*
* Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
*
* 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.
*
*/
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/power_supply.h>
#include <linux/power/jz4740-battery.h>
#include <linux/jz4740-adc.h>
struct jz_battery {
struct jz_battery_platform_data *pdata;
struct platform_device *pdev;
void __iomem *base;
int irq;
int charge_irq;
const struct mfd_cell *cell;
int status;
long voltage;
struct completion read_completion;
struct power_supply *battery;
struct power_supply_desc battery_desc;
struct delayed_work work;
struct mutex lock;
};
static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
{
return power_supply_get_drvdata(psy);
}
static irqreturn_t jz_battery_irq_handler(int irq, void *devid)
{
struct jz_battery *battery = devid;
complete(&battery->read_completion);
return IRQ_HANDLED;
}
static long jz_battery_read_voltage(struct jz_battery *battery)
{
long t;
unsigned long val;
long voltage;
mutex_lock(&battery->lock);
reinit_completion(&battery->read_completion);
enable_irq(battery->irq);
battery->cell->enable(battery->pdev);
t = wait_for_completion_interruptible_timeout(&battery->read_completion,
HZ);
if (t > 0) {
val = readw(battery->base) & 0xfff;
if (battery->pdata->info.voltage_max_design <= 2500000)
val = (val * 78125UL) >> 7UL;
else
val = ((val * 924375UL) >> 9UL) + 33000;
voltage = (long)val;
} else {
voltage = t ? t : -ETIMEDOUT;
}
battery->cell->disable(battery->pdev);
disable_irq(battery->irq);
mutex_unlock(&battery->lock);
return voltage;
}
static int jz_battery_get_capacity(struct power_supply *psy)
{
struct jz_battery *jz_battery = psy_to_jz_battery(psy);
struct power_supply_info *info = &jz_battery->pdata->info;
long voltage;
int ret;
int voltage_span;
voltage = jz_battery_read_voltage(jz_battery);
if (voltage < 0)
return voltage;
voltage_span = info->voltage_max_design - info->voltage_min_design;
ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;
if (ret > 100)
ret = 100;
else if (ret < 0)
ret = 0;
return ret;
}
static int jz_battery_get_property(struct power_supply *psy,
enum power_supply_property psp, union power_supply_propval *val)
{
struct jz_battery *jz_battery = psy_to_jz_battery(psy);
struct power_supply_info *info = &jz_battery->pdata->info;
long voltage;
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = jz_battery->status;
break;
case POWER_SUPPLY_PROP_TECHNOLOGY:
val->intval = jz_battery->pdata->info.technology;
break;
case POWER_SUPPLY_PROP_HEALTH:
voltage = jz_battery_read_voltage(jz_battery);
if (voltage < info->voltage_min_design)
val->intval = POWER_SUPPLY_HEALTH_DEAD;
else
val->intval = POWER_SUPPLY_HEALTH_GOOD;
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = jz_battery_get_capacity(psy);
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = jz_battery_read_voltage(jz_battery);
if (val->intval < 0)
return val->intval;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
val->intval = info->voltage_max_design;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
val->intval = info->voltage_min_design;
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = 1;
break;
default:
return -EINVAL;
}
return 0;
}
static void jz_battery_external_power_changed(struct power_supply *psy)
{
struct jz_battery *jz_battery = psy_to_jz_battery(psy);
mod_delayed_work(system_wq, &jz_battery->work, 0);
}
static irqreturn_t jz_battery_charge_irq(int irq, void *data)
{
struct jz_battery *jz_battery = data;
mod_delayed_work(system_wq, &jz_battery->work, 0);
return IRQ_HANDLED;
}
static void jz_battery_update(struct jz_battery *jz_battery)
{
int status;
long voltage;
bool has_changed = false;
int is_charging;
if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
is_charging ^= jz_battery->pdata->gpio_charge_active_low;
if (is_charging)
status = POWER_SUPPLY_STATUS_CHARGING;
else
status = POWER_SUPPLY_STATUS_NOT_CHARGING;
if (status != jz_battery->status) {
jz_battery->status = status;
has_changed = true;
}
}
voltage = jz_battery_read_voltage(jz_battery);
if (abs(voltage - jz_battery->voltage) < 50000) {
jz_battery->voltage = voltage;
has_changed = true;
}
if (has_changed)
power_supply_changed(jz_battery->battery);
}
static enum power_supply_property jz_battery_properties[] = {
POWER_SUPPLY_PROP_STATUS,
POWER_SUPPLY_PROP_TECHNOLOGY,
POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
POWER_SUPPLY_PROP_PRESENT,
};
static void jz_battery_work(struct work_struct *work)
{
/* Too small interval will increase system workload */
const int interval = HZ * 30;
struct jz_battery *jz_battery = container_of(work, struct jz_battery,
work.work);
jz_battery_update(jz_battery);
schedule_delayed_work(&jz_battery->work, interval);
}
static int jz_battery_probe(struct platform_device *pdev)
{
int ret = 0;
struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
struct power_supply_config psy_cfg = {};
struct jz_battery *jz_battery;
struct power_supply_desc *battery_desc;
struct resource *mem;
if (!pdata) {
dev_err(&pdev->dev, "No platform_data supplied\n");
return -ENXIO;
}
jz_battery = devm_kzalloc(&pdev->dev, sizeof(*jz_battery), GFP_KERNEL);
if (!jz_battery) {
dev_err(&pdev->dev, "Failed to allocate driver structure\n");
return -ENOMEM;
}
jz_battery->cell = mfd_get_cell(pdev);
jz_battery->irq = platform_get_irq(pdev, 0);
if (jz_battery->irq < 0) {
dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
return jz_battery->irq;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
jz_battery->base = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(jz_battery->base))
return PTR_ERR(jz_battery->base);
battery_desc = &jz_battery->battery_desc;
battery_desc->name = pdata->info.name;
battery_desc->type = POWER_SUPPLY_TYPE_BATTERY;
battery_desc->properties = jz_battery_properties;
battery_desc->num_properties = ARRAY_SIZE(jz_battery_properties);
battery_desc->get_property = jz_battery_get_property;
battery_desc->external_power_changed =
jz_battery_external_power_changed;
battery_desc->use_for_apm = 1;
psy_cfg.drv_data = jz_battery;
jz_battery->pdata = pdata;
jz_battery->pdev = pdev;
init_completion(&jz_battery->read_completion);
mutex_init(&jz_battery->lock);
INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
jz_battery);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
return ret;
}
disable_irq(jz_battery->irq);
if (gpio_is_valid(pdata->gpio_charge)) {
ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
if (ret) {
dev_err(&pdev->dev, "charger state gpio request failed.\n");
goto err_free_irq;
}
ret = gpio_direction_input(pdata->gpio_charge);
if (ret) {
dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
goto err_free_gpio;
}
jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
if (jz_battery->charge_irq >= 0) {
ret = request_irq(jz_battery->charge_irq,
jz_battery_charge_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
dev_name(&pdev->dev), jz_battery);
if (ret) {
dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
goto err_free_gpio;
}
}
} else {
jz_battery->charge_irq = -1;
}
if (jz_battery->pdata->info.voltage_max_design <= 2500000)
jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
JZ_ADC_CONFIG_BAT_MB);
else
jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);
jz_battery->battery = power_supply_register(&pdev->dev, battery_desc,
&psy_cfg);
if (IS_ERR(jz_battery->battery)) {
dev_err(&pdev->dev, "power supply battery register failed.\n");
ret = PTR_ERR(jz_battery->battery);
goto err_free_charge_irq;
}
platform_set_drvdata(pdev, jz_battery);
schedule_delayed_work(&jz_battery->work, 0);
return 0;
err_free_charge_irq:
if (jz_battery->charge_irq >= 0)
free_irq(jz_battery->charge_irq, jz_battery);
err_free_gpio:
if (gpio_is_valid(pdata->gpio_charge))
gpio_free(jz_battery->pdata->gpio_charge);
err_free_irq:
free_irq(jz_battery->irq, jz_battery);
return ret;
}
static int jz_battery_remove(struct platform_device *pdev)
{
struct jz_battery *jz_battery = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&jz_battery->work);
if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
if (jz_battery->charge_irq >= 0)
free_irq(jz_battery->charge_irq, jz_battery);
gpio_free(jz_battery->pdata->gpio_charge);
}
power_supply_unregister(jz_battery->battery);
free_irq(jz_battery->irq, jz_battery);
return 0;
}
#ifdef CONFIG_PM
static int jz_battery_suspend(struct device *dev)
{
struct jz_battery *jz_battery = dev_get_drvdata(dev);
cancel_delayed_work_sync(&jz_battery->work);
jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;
return 0;
}
static int jz_battery_resume(struct device *dev)
{
struct jz_battery *jz_battery = dev_get_drvdata(dev);
schedule_delayed_work(&jz_battery->work, 0);
return 0;
}
static const struct dev_pm_ops jz_battery_pm_ops = {
.suspend = jz_battery_suspend,
.resume = jz_battery_resume,
};
#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
#else
#define JZ_BATTERY_PM_OPS NULL
#endif
static struct platform_driver jz_battery_driver = {
.probe = jz_battery_probe,
.remove = jz_battery_remove,
.driver = {
.name = "jz4740-battery",
.pm = JZ_BATTERY_PM_OPS,
},
};
module_platform_driver(jz_battery_driver);
MODULE_ALIAS("platform:jz4740-battery");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("JZ4740 SoC battery driver");