kernel_optimize_test/drivers/power/bq24735-charger.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

425 lines
10 KiB
C

/*
* Battery charger driver for TI BQ24735
*
* Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/power/bq24735-charger.h>
#define BQ24735_CHG_OPT 0x12
#define BQ24735_CHG_OPT_CHARGE_DISABLE (1 << 0)
#define BQ24735_CHG_OPT_AC_PRESENT (1 << 4)
#define BQ24735_CHARGE_CURRENT 0x14
#define BQ24735_CHARGE_CURRENT_MASK 0x1fc0
#define BQ24735_CHARGE_VOLTAGE 0x15
#define BQ24735_CHARGE_VOLTAGE_MASK 0x7ff0
#define BQ24735_INPUT_CURRENT 0x3f
#define BQ24735_INPUT_CURRENT_MASK 0x1f80
#define BQ24735_MANUFACTURER_ID 0xfe
#define BQ24735_DEVICE_ID 0xff
struct bq24735 {
struct power_supply *charger;
struct power_supply_desc charger_desc;
struct i2c_client *client;
struct bq24735_platform *pdata;
};
static inline struct bq24735 *to_bq24735(struct power_supply *psy)
{
return power_supply_get_drvdata(psy);
}
static enum power_supply_property bq24735_charger_properties[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
u16 value)
{
return i2c_smbus_write_word_data(client, reg, le16_to_cpu(value));
}
static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
{
s32 ret = i2c_smbus_read_word_data(client, reg);
return ret < 0 ? ret : le16_to_cpu(ret);
}
static int bq24735_update_word(struct i2c_client *client, u8 reg,
u16 mask, u16 value)
{
unsigned int tmp;
int ret;
ret = bq24735_read_word(client, reg);
if (ret < 0)
return ret;
tmp = ret & ~mask;
tmp |= value & mask;
return bq24735_write_word(client, reg, tmp);
}
static inline int bq24735_enable_charging(struct bq24735 *charger)
{
return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
BQ24735_CHG_OPT_CHARGE_DISABLE,
~BQ24735_CHG_OPT_CHARGE_DISABLE);
}
static inline int bq24735_disable_charging(struct bq24735 *charger)
{
return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
BQ24735_CHG_OPT_CHARGE_DISABLE,
BQ24735_CHG_OPT_CHARGE_DISABLE);
}
static int bq24735_config_charger(struct bq24735 *charger)
{
struct bq24735_platform *pdata = charger->pdata;
int ret;
u16 value;
if (pdata->charge_current) {
value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
ret = bq24735_write_word(charger->client,
BQ24735_CHARGE_CURRENT, value);
if (ret < 0) {
dev_err(&charger->client->dev,
"Failed to write charger current : %d\n",
ret);
return ret;
}
}
if (pdata->charge_voltage) {
value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
ret = bq24735_write_word(charger->client,
BQ24735_CHARGE_VOLTAGE, value);
if (ret < 0) {
dev_err(&charger->client->dev,
"Failed to write charger voltage : %d\n",
ret);
return ret;
}
}
if (pdata->input_current) {
value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
ret = bq24735_write_word(charger->client,
BQ24735_INPUT_CURRENT, value);
if (ret < 0) {
dev_err(&charger->client->dev,
"Failed to write input current : %d\n",
ret);
return ret;
}
}
return 0;
}
static bool bq24735_charger_is_present(struct bq24735 *charger)
{
struct bq24735_platform *pdata = charger->pdata;
int ret;
if (pdata->status_gpio_valid) {
ret = gpio_get_value_cansleep(pdata->status_gpio);
return ret ^= pdata->status_gpio_active_low == 0;
} else {
int ac = 0;
ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
if (ac < 0) {
dev_err(&charger->client->dev,
"Failed to read charger options : %d\n",
ac);
return false;
}
return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
}
return false;
}
static irqreturn_t bq24735_charger_isr(int irq, void *devid)
{
struct power_supply *psy = devid;
struct bq24735 *charger = to_bq24735(psy);
if (bq24735_charger_is_present(charger))
bq24735_enable_charging(charger);
else
bq24735_disable_charging(charger);
power_supply_changed(psy);
return IRQ_HANDLED;
}
static int bq24735_charger_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct bq24735 *charger = to_bq24735(psy);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
break;
default:
return -EINVAL;
}
return 0;
}
static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
{
struct bq24735_platform *pdata;
struct device_node *np = client->dev.of_node;
u32 val;
int ret;
enum of_gpio_flags flags;
pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
dev_err(&client->dev,
"Memory alloc for bq24735 pdata failed\n");
return NULL;
}
pdata->status_gpio = of_get_named_gpio_flags(np, "ti,ac-detect-gpios",
0, &flags);
if (flags & OF_GPIO_ACTIVE_LOW)
pdata->status_gpio_active_low = 1;
ret = of_property_read_u32(np, "ti,charge-current", &val);
if (!ret)
pdata->charge_current = val;
ret = of_property_read_u32(np, "ti,charge-voltage", &val);
if (!ret)
pdata->charge_voltage = val;
ret = of_property_read_u32(np, "ti,input-current", &val);
if (!ret)
pdata->input_current = val;
return pdata;
}
static int bq24735_charger_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct bq24735 *charger;
struct power_supply_desc *supply_desc;
struct power_supply_config psy_cfg = {};
char *name;
charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
if (!charger)
return -ENOMEM;
charger->pdata = client->dev.platform_data;
if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
charger->pdata = bq24735_parse_dt_data(client);
if (!charger->pdata) {
dev_err(&client->dev, "no platform data provided\n");
return -EINVAL;
}
name = (char *)charger->pdata->name;
if (!name) {
name = kasprintf(GFP_KERNEL, "bq24735@%s",
dev_name(&client->dev));
if (!name) {
dev_err(&client->dev, "Failed to alloc device name\n");
return -ENOMEM;
}
}
charger->client = client;
supply_desc = &charger->charger_desc;
supply_desc->name = name;
supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
supply_desc->properties = bq24735_charger_properties;
supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
supply_desc->get_property = bq24735_charger_get_property;
psy_cfg.supplied_to = charger->pdata->supplied_to;
psy_cfg.num_supplicants = charger->pdata->num_supplicants;
psy_cfg.of_node = client->dev.of_node;
psy_cfg.drv_data = charger;
i2c_set_clientdata(client, charger);
ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
if (ret < 0) {
dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
ret);
goto err_free_name;
} else if (ret != 0x0040) {
dev_err(&client->dev,
"manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
ret = -ENODEV;
goto err_free_name;
}
ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
if (ret < 0) {
dev_err(&client->dev, "Failed to read device id : %d\n", ret);
goto err_free_name;
} else if (ret != 0x000B) {
dev_err(&client->dev,
"device id mismatch. 0x000b != 0x%04x\n", ret);
ret = -ENODEV;
goto err_free_name;
}
if (gpio_is_valid(charger->pdata->status_gpio)) {
ret = devm_gpio_request(&client->dev,
charger->pdata->status_gpio,
name);
if (ret) {
dev_err(&client->dev,
"Failed GPIO request for GPIO %d: %d\n",
charger->pdata->status_gpio, ret);
}
charger->pdata->status_gpio_valid = !ret;
}
ret = bq24735_config_charger(charger);
if (ret < 0) {
dev_err(&client->dev, "failed in configuring charger");
goto err_free_name;
}
/* check for AC adapter presence */
if (bq24735_charger_is_present(charger)) {
ret = bq24735_enable_charging(charger);
if (ret < 0) {
dev_err(&client->dev, "Failed to enable charging\n");
goto err_free_name;
}
}
charger->charger = power_supply_register(&client->dev, supply_desc,
&psy_cfg);
if (IS_ERR(charger->charger)) {
ret = PTR_ERR(charger->charger);
dev_err(&client->dev, "Failed to register power supply: %d\n",
ret);
goto err_free_name;
}
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, bq24735_charger_isr,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING |
IRQF_ONESHOT,
supply_desc->name,
charger->charger);
if (ret) {
dev_err(&client->dev,
"Unable to register IRQ %d err %d\n",
client->irq, ret);
goto err_unregister_supply;
}
}
return 0;
err_unregister_supply:
power_supply_unregister(charger->charger);
err_free_name:
if (name != charger->pdata->name)
kfree(name);
return ret;
}
static int bq24735_charger_remove(struct i2c_client *client)
{
struct bq24735 *charger = i2c_get_clientdata(client);
if (charger->client->irq)
devm_free_irq(&charger->client->dev, charger->client->irq,
&charger->charger);
power_supply_unregister(charger->charger);
if (charger->charger_desc.name != charger->pdata->name)
kfree(charger->charger_desc.name);
return 0;
}
static const struct i2c_device_id bq24735_charger_id[] = {
{ "bq24735-charger", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
static const struct of_device_id bq24735_match_ids[] = {
{ .compatible = "ti,bq24735", },
{ /* end */ }
};
MODULE_DEVICE_TABLE(of, bq24735_match_ids);
static struct i2c_driver bq24735_charger_driver = {
.driver = {
.name = "bq24735-charger",
.owner = THIS_MODULE,
.of_match_table = bq24735_match_ids,
},
.probe = bq24735_charger_probe,
.remove = bq24735_charger_remove,
.id_table = bq24735_charger_id,
};
module_i2c_driver(bq24735_charger_driver);
MODULE_DESCRIPTION("bq24735 battery charging driver");
MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
MODULE_LICENSE("GPL v2");