regulator: core: Use ww_mutex for regulators locking

Wait/wound mutex shall be used in order to avoid lockups on locking of
coupled regulators.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Suggested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Dmitry Osipenko 2018-11-19 00:56:17 +03:00 committed by Mark Brown
parent 6303f3e78b
commit f8702f9e4a
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
5 changed files with 317 additions and 104 deletions

View File

@ -50,6 +50,8 @@
#define rdev_dbg(rdev, fmt, ...) \
pr_debug("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)
static DEFINE_WW_CLASS(regulator_ww_class);
static DEFINE_MUTEX(regulator_nesting_mutex);
static DEFINE_MUTEX(regulator_list_mutex);
static LIST_HEAD(regulator_map_list);
static LIST_HEAD(regulator_ena_gpio_list);
@ -154,7 +156,7 @@ static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev)
/**
* regulator_lock_nested - lock a single regulator
* @rdev: regulator source
* @subclass: mutex subclass used for lockdep
* @ww_ctx: w/w mutex acquire context
*
* This function can be called many times by one task on
* a single regulator and its mutex will be locked only
@ -162,24 +164,52 @@ static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev)
* than the one, which initially locked the mutex, it will
* wait on mutex.
*/
static void regulator_lock_nested(struct regulator_dev *rdev,
unsigned int subclass)
static inline int regulator_lock_nested(struct regulator_dev *rdev,
struct ww_acquire_ctx *ww_ctx)
{
if (!mutex_trylock(&rdev->mutex)) {
if (rdev->mutex_owner == current) {
bool lock = false;
int ret = 0;
mutex_lock(&regulator_nesting_mutex);
if (ww_ctx || !ww_mutex_trylock(&rdev->mutex)) {
if (rdev->mutex_owner == current)
rdev->ref_cnt++;
return;
else
lock = true;
if (lock) {
mutex_unlock(&regulator_nesting_mutex);
ret = ww_mutex_lock(&rdev->mutex, ww_ctx);
mutex_lock(&regulator_nesting_mutex);
}
mutex_lock_nested(&rdev->mutex, subclass);
} else {
lock = true;
}
rdev->ref_cnt = 1;
rdev->mutex_owner = current;
if (lock && ret != -EDEADLK) {
rdev->ref_cnt++;
rdev->mutex_owner = current;
}
mutex_unlock(&regulator_nesting_mutex);
return ret;
}
static inline void regulator_lock(struct regulator_dev *rdev)
/**
* regulator_lock - lock a single regulator
* @rdev: regulator source
*
* This function can be called many times by one task on
* a single regulator and its mutex will be locked only
* once. If a task, which is calling this function is other
* than the one, which initially locked the mutex, it will
* wait on mutex.
*/
void regulator_lock(struct regulator_dev *rdev)
{
regulator_lock_nested(rdev, 0);
regulator_lock_nested(rdev, NULL);
}
/**
@ -189,23 +219,48 @@ static inline void regulator_lock(struct regulator_dev *rdev)
* This function unlocks the mutex when the
* reference counter reaches 0.
*/
static void regulator_unlock(struct regulator_dev *rdev)
void regulator_unlock(struct regulator_dev *rdev)
{
if (rdev->ref_cnt != 0) {
rdev->ref_cnt--;
mutex_lock(&regulator_nesting_mutex);
if (!rdev->ref_cnt) {
rdev->mutex_owner = NULL;
mutex_unlock(&rdev->mutex);
}
if (--rdev->ref_cnt == 0) {
rdev->mutex_owner = NULL;
ww_mutex_unlock(&rdev->mutex);
}
WARN_ON_ONCE(rdev->ref_cnt < 0);
mutex_unlock(&regulator_nesting_mutex);
}
static void regulator_unlock_recursive(struct regulator_dev *rdev,
unsigned int n_coupled)
{
struct regulator_dev *c_rdev;
int i;
for (i = n_coupled; i > 0; i--) {
c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1];
if (!c_rdev)
continue;
if (c_rdev->supply)
regulator_unlock_recursive(
c_rdev->supply->rdev,
c_rdev->coupling_desc.n_coupled);
regulator_unlock(c_rdev);
}
}
static int regulator_lock_recursive(struct regulator_dev *rdev,
unsigned int subclass)
struct regulator_dev **new_contended_rdev,
struct regulator_dev **old_contended_rdev,
struct ww_acquire_ctx *ww_ctx)
{
struct regulator_dev *c_rdev;
int i;
int i, err;
for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {
c_rdev = rdev->coupling_desc.coupled_rdevs[i];
@ -213,52 +268,95 @@ static int regulator_lock_recursive(struct regulator_dev *rdev,
if (!c_rdev)
continue;
regulator_lock_nested(c_rdev, subclass++);
if (c_rdev != *old_contended_rdev) {
err = regulator_lock_nested(c_rdev, ww_ctx);
if (err) {
if (err == -EDEADLK) {
*new_contended_rdev = c_rdev;
goto err_unlock;
}
if (c_rdev->supply)
subclass =
regulator_lock_recursive(c_rdev->supply->rdev,
subclass);
/* shouldn't happen */
WARN_ON_ONCE(err != -EALREADY);
}
} else {
*old_contended_rdev = NULL;
}
if (c_rdev->supply) {
err = regulator_lock_recursive(c_rdev->supply->rdev,
new_contended_rdev,
old_contended_rdev,
ww_ctx);
if (err) {
regulator_unlock(c_rdev);
goto err_unlock;
}
}
}
return subclass;
return 0;
err_unlock:
regulator_unlock_recursive(rdev, i);
return err;
}
/**
* regulator_unlock_dependent - unlock regulator's suppliers and coupled
* regulators
* @rdev: regulator source
* @ww_ctx: w/w mutex acquire context
*
* Unlock all regulators related with rdev by coupling or suppling.
*/
static void regulator_unlock_dependent(struct regulator_dev *rdev)
static void regulator_unlock_dependent(struct regulator_dev *rdev,
struct ww_acquire_ctx *ww_ctx)
{
struct regulator_dev *c_rdev;
int i;
for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {
c_rdev = rdev->coupling_desc.coupled_rdevs[i];
if (!c_rdev)
continue;
regulator_unlock(c_rdev);
if (c_rdev->supply)
regulator_unlock_dependent(c_rdev->supply->rdev);
}
regulator_unlock_recursive(rdev, rdev->coupling_desc.n_coupled);
ww_acquire_fini(ww_ctx);
}
/**
* regulator_lock_dependent - lock regulator's suppliers and coupled regulators
* @rdev: regulator source
* @ww_ctx: w/w mutex acquire context
*
* This function as a wrapper on regulator_lock_recursive(), which locks
* all regulators related with rdev by coupling or suppling.
*/
static inline void regulator_lock_dependent(struct regulator_dev *rdev)
static void regulator_lock_dependent(struct regulator_dev *rdev,
struct ww_acquire_ctx *ww_ctx)
{
regulator_lock_recursive(rdev, 0);
struct regulator_dev *new_contended_rdev = NULL;
struct regulator_dev *old_contended_rdev = NULL;
int err;
mutex_lock(&regulator_list_mutex);
ww_acquire_init(ww_ctx, &regulator_ww_class);
do {
if (new_contended_rdev) {
ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
old_contended_rdev = new_contended_rdev;
old_contended_rdev->ref_cnt++;
}
err = regulator_lock_recursive(rdev,
&new_contended_rdev,
&old_contended_rdev,
ww_ctx);
if (old_contended_rdev)
regulator_unlock(old_contended_rdev);
} while (err == -EDEADLK);
ww_acquire_done(ww_ctx);
mutex_unlock(&regulator_list_mutex);
}
/**
@ -772,7 +870,7 @@ static int drms_uA_update(struct regulator_dev *rdev)
int current_uA = 0, output_uV, input_uV, err;
unsigned int mode;
lockdep_assert_held_once(&rdev->mutex);
lockdep_assert_held_once(&rdev->mutex.base);
/*
* first check to see if we can set modes at all, otherwise just
@ -2274,7 +2372,20 @@ static int _regulator_enable(struct regulator_dev *rdev)
{
int ret;
lockdep_assert_held_once(&rdev->mutex);
lockdep_assert_held_once(&rdev->mutex.base);
if (rdev->supply) {
ret = _regulator_enable(rdev->supply->rdev);
if (ret < 0)
return ret;
}
/* balance only if there are regulators coupled */
if (rdev->coupling_desc.n_coupled > 1) {
ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
if (ret < 0)
goto err_disable_supply;
}
/* check voltage and requested load before enabling */
if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_DRMS))
@ -2285,18 +2396,20 @@ static int _regulator_enable(struct regulator_dev *rdev)
ret = _regulator_is_enabled(rdev);
if (ret == -EINVAL || ret == 0) {
if (!regulator_ops_is_valid(rdev,
REGULATOR_CHANGE_STATUS))
return -EPERM;
REGULATOR_CHANGE_STATUS)) {
ret = -EPERM;
goto err_disable_supply;
}
ret = _regulator_do_enable(rdev);
if (ret < 0)
return ret;
goto err_disable_supply;
_notifier_call_chain(rdev, REGULATOR_EVENT_ENABLE,
NULL);
} else if (ret < 0) {
rdev_err(rdev, "is_enabled() failed: %d\n", ret);
return ret;
goto err_disable_supply;
}
/* Fallthrough on positive return values - already enabled */
}
@ -2304,6 +2417,12 @@ static int _regulator_enable(struct regulator_dev *rdev)
rdev->use_count++;
return 0;
err_disable_supply:
if (rdev->supply)
_regulator_disable(rdev->supply->rdev);
return ret;
}
/**
@ -2320,30 +2439,15 @@ static int _regulator_enable(struct regulator_dev *rdev)
int regulator_enable(struct regulator *regulator)
{
struct regulator_dev *rdev = regulator->rdev;
struct ww_acquire_ctx ww_ctx;
int ret = 0;
if (regulator->always_on)
return 0;
if (rdev->supply) {
ret = regulator_enable(rdev->supply);
if (ret != 0)
return ret;
}
regulator_lock_dependent(rdev);
/* balance only if there are regulators coupled */
if (rdev->coupling_desc.n_coupled > 1) {
ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
if (ret != 0)
goto unlock;
}
regulator_lock_dependent(rdev, &ww_ctx);
ret = _regulator_enable(rdev);
unlock:
regulator_unlock_dependent(rdev);
if (ret != 0 && rdev->supply)
regulator_disable(rdev->supply);
regulator_unlock_dependent(rdev, &ww_ctx);
return ret;
}
@ -2385,7 +2489,7 @@ static int _regulator_disable(struct regulator_dev *rdev)
{
int ret = 0;
lockdep_assert_held_once(&rdev->mutex);
lockdep_assert_held_once(&rdev->mutex.base);
if (WARN(rdev->use_count <= 0,
"unbalanced disables for %s\n", rdev_get_name(rdev)))
@ -2423,6 +2527,12 @@ static int _regulator_disable(struct regulator_dev *rdev)
rdev->use_count--;
}
if (ret == 0 && rdev->coupling_desc.n_coupled > 1)
ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
if (ret == 0 && rdev->supply)
ret = _regulator_disable(rdev->supply->rdev);
return ret;
}
@ -2441,19 +2551,15 @@ static int _regulator_disable(struct regulator_dev *rdev)
int regulator_disable(struct regulator *regulator)
{
struct regulator_dev *rdev = regulator->rdev;
struct ww_acquire_ctx ww_ctx;
int ret = 0;
if (regulator->always_on)
return 0;
regulator_lock_dependent(rdev);
regulator_lock_dependent(rdev, &ww_ctx);
ret = _regulator_disable(rdev);
if (rdev->coupling_desc.n_coupled > 1)
regulator_balance_voltage(rdev, PM_SUSPEND_ON);
regulator_unlock_dependent(rdev);
if (ret == 0 && rdev->supply)
regulator_disable(rdev->supply);
regulator_unlock_dependent(rdev, &ww_ctx);
return ret;
}
@ -2464,7 +2570,7 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
{
int ret = 0;
lockdep_assert_held_once(&rdev->mutex);
lockdep_assert_held_once(&rdev->mutex.base);
ret = _notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
REGULATOR_EVENT_PRE_DISABLE, NULL);
@ -2497,14 +2603,15 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
int regulator_force_disable(struct regulator *regulator)
{
struct regulator_dev *rdev = regulator->rdev;
struct ww_acquire_ctx ww_ctx;
int ret;
regulator_lock_dependent(rdev);
regulator_lock_dependent(rdev, &ww_ctx);
regulator->uA_load = 0;
ret = _regulator_force_disable(regulator->rdev);
if (rdev->coupling_desc.n_coupled > 1)
regulator_balance_voltage(rdev, PM_SUSPEND_ON);
regulator_unlock_dependent(rdev);
regulator_unlock_dependent(rdev, &ww_ctx);
if (rdev->supply)
while (rdev->open_count--)
@ -2518,9 +2625,10 @@ static void regulator_disable_work(struct work_struct *work)
{
struct regulator_dev *rdev = container_of(work, struct regulator_dev,
disable_work.work);
struct ww_acquire_ctx ww_ctx;
int count, i, ret;
regulator_lock(rdev);
regulator_lock_dependent(rdev, &ww_ctx);
BUG_ON(!rdev->deferred_disables);
@ -2541,7 +2649,10 @@ static void regulator_disable_work(struct work_struct *work)
rdev_err(rdev, "Deferred disable failed: %d\n", ret);
}
regulator_unlock(rdev);
if (rdev->coupling_desc.n_coupled > 1)
regulator_balance_voltage(rdev, PM_SUSPEND_ON);
regulator_unlock_dependent(rdev, &ww_ctx);
if (rdev->supply) {
for (i = 0; i < count; i++) {
@ -2652,9 +2763,9 @@ int regulator_is_enabled(struct regulator *regulator)
if (regulator->always_on)
return 1;
regulator_lock_dependent(regulator->rdev);
regulator_lock(regulator->rdev);
ret = _regulator_is_enabled(regulator->rdev);
regulator_unlock_dependent(regulator->rdev);
regulator_unlock(regulator->rdev);
return ret;
}
@ -3268,7 +3379,7 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
int tmp_min = 0;
int tmp_max = INT_MAX;
lockdep_assert_held_once(&c_rdevs[i]->mutex);
lockdep_assert_held_once(&c_rdevs[i]->mutex.base);
ret = regulator_check_consumers(c_rdevs[i],
&tmp_min,
@ -3479,14 +3590,15 @@ out:
*/
int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
{
int ret = 0;
struct ww_acquire_ctx ww_ctx;
int ret;
regulator_lock_dependent(regulator->rdev);
regulator_lock_dependent(regulator->rdev, &ww_ctx);
ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV,
PM_SUSPEND_ON);
regulator_unlock_dependent(regulator->rdev);
regulator_unlock_dependent(regulator->rdev, &ww_ctx);
return ret;
}
@ -3558,18 +3670,19 @@ static int _regulator_set_suspend_voltage(struct regulator *regulator,
int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV,
int max_uV, suspend_state_t state)
{
int ret = 0;
struct ww_acquire_ctx ww_ctx;
int ret;
/* PM_SUSPEND_ON is handled by regulator_set_voltage() */
if (regulator_check_states(state) || state == PM_SUSPEND_ON)
return -EINVAL;
regulator_lock_dependent(regulator->rdev);
regulator_lock_dependent(regulator->rdev, &ww_ctx);
ret = _regulator_set_suspend_voltage(regulator, min_uV,
max_uV, state);
regulator_unlock_dependent(regulator->rdev);
regulator_unlock_dependent(regulator->rdev, &ww_ctx);
return ret;
}
@ -3759,13 +3872,12 @@ static int _regulator_get_voltage(struct regulator_dev *rdev)
*/
int regulator_get_voltage(struct regulator *regulator)
{
struct ww_acquire_ctx ww_ctx;
int ret;
regulator_lock_dependent(regulator->rdev);
regulator_lock_dependent(regulator->rdev, &ww_ctx);
ret = _regulator_get_voltage(regulator->rdev);
regulator_unlock_dependent(regulator->rdev);
regulator_unlock_dependent(regulator->rdev, &ww_ctx);
return ret;
}
@ -4301,7 +4413,7 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free);
int regulator_notifier_call_chain(struct regulator_dev *rdev,
unsigned long event, void *data)
{
lockdep_assert_held_once(&rdev->mutex);
lockdep_assert_held_once(&rdev->mutex.base);
_notifier_call_chain(rdev, event, data);
return NOTIFY_DONE;
@ -4669,7 +4781,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
rdev->dev.of_node = of_node_get(config->of_node);
}
mutex_init(&rdev->mutex);
ww_mutex_init(&rdev->mutex, &regulator_ww_class);
rdev->reg_data = config->driver_data;
rdev->owner = regulator_desc->owner;
rdev->desc = regulator_desc;
@ -5026,8 +5138,6 @@ static void regulator_summary_show_subtree(struct seq_file *s,
if (!rdev)
return;
regulator_lock_nested(rdev, level);
opmode = _regulator_get_mode_unlocked(rdev);
seq_printf(s, "%*s%-*s %3d %4d %6d %7s ",
level * 3 + 1, "",
@ -5084,8 +5194,101 @@ static void regulator_summary_show_subtree(struct seq_file *s,
class_for_each_device(&regulator_class, NULL, &summary_data,
regulator_summary_show_children);
}
struct summary_lock_data {
struct ww_acquire_ctx *ww_ctx;
struct regulator_dev **new_contended_rdev;
struct regulator_dev **old_contended_rdev;
};
static int regulator_summary_lock_one(struct device *dev, void *data)
{
struct regulator_dev *rdev = dev_to_rdev(dev);
struct summary_lock_data *lock_data = data;
int ret = 0;
if (rdev != *lock_data->old_contended_rdev) {
ret = regulator_lock_nested(rdev, lock_data->ww_ctx);
if (ret == -EDEADLK)
*lock_data->new_contended_rdev = rdev;
else
WARN_ON_ONCE(ret);
} else {
*lock_data->old_contended_rdev = NULL;
}
return ret;
}
static int regulator_summary_unlock_one(struct device *dev, void *data)
{
struct regulator_dev *rdev = dev_to_rdev(dev);
struct summary_lock_data *lock_data = data;
if (lock_data) {
if (rdev == *lock_data->new_contended_rdev)
return -EDEADLK;
}
regulator_unlock(rdev);
return 0;
}
static int regulator_summary_lock_all(struct ww_acquire_ctx *ww_ctx,
struct regulator_dev **new_contended_rdev,
struct regulator_dev **old_contended_rdev)
{
struct summary_lock_data lock_data;
int ret;
lock_data.ww_ctx = ww_ctx;
lock_data.new_contended_rdev = new_contended_rdev;
lock_data.old_contended_rdev = old_contended_rdev;
ret = class_for_each_device(&regulator_class, NULL, &lock_data,
regulator_summary_lock_one);
if (ret)
class_for_each_device(&regulator_class, NULL, &lock_data,
regulator_summary_unlock_one);
return ret;
}
static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx)
{
struct regulator_dev *new_contended_rdev = NULL;
struct regulator_dev *old_contended_rdev = NULL;
int err;
ww_acquire_init(ww_ctx, &regulator_ww_class);
do {
if (new_contended_rdev) {
ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
old_contended_rdev = new_contended_rdev;
old_contended_rdev->ref_cnt++;
}
err = regulator_summary_lock_all(ww_ctx,
&new_contended_rdev,
&old_contended_rdev);
if (old_contended_rdev)
regulator_unlock(old_contended_rdev);
} while (err == -EDEADLK);
ww_acquire_done(ww_ctx);
}
static void regulator_summary_unlock(struct ww_acquire_ctx *ww_ctx)
{
class_for_each_device(&regulator_class, NULL, NULL,
regulator_summary_unlock_one);
ww_acquire_fini(ww_ctx);
}
static int regulator_summary_show_roots(struct device *dev, void *data)
@ -5101,12 +5304,18 @@ static int regulator_summary_show_roots(struct device *dev, void *data)
static int regulator_summary_show(struct seq_file *s, void *data)
{
struct ww_acquire_ctx ww_ctx;
seq_puts(s, " regulator use open bypass opmode voltage current min max\n");
seq_puts(s, "---------------------------------------------------------------------------------------\n");
regulator_summary_lock(&ww_ctx);
class_for_each_device(&regulator_class, NULL, s,
regulator_summary_show_roots);
regulator_summary_unlock(&ww_ctx);
return 0;
}

View File

@ -131,7 +131,7 @@ static irqreturn_t da9210_irq_handler(int irq, void *data)
if (error < 0)
goto error_i2c;
mutex_lock(&chip->rdev->mutex);
regulator_lock(chip->rdev);
if (val & DA9210_E_OVCURR) {
regulator_notifier_call_chain(chip->rdev,
@ -157,7 +157,7 @@ static irqreturn_t da9210_irq_handler(int irq, void *data)
handled |= DA9210_E_VMAX;
}
mutex_unlock(&chip->rdev->mutex);
regulator_unlock(chip->rdev);
if (handled) {
/* Clear handled events */

View File

@ -489,14 +489,14 @@ static irqreturn_t stpmic1_curlim_irq_handler(int irq, void *data)
{
struct regulator_dev *rdev = (struct regulator_dev *)data;
mutex_lock(&rdev->mutex);
regulator_lock(rdev, NULL);
/* Send an overcurrent notification */
regulator_notifier_call_chain(rdev,
REGULATOR_EVENT_OVER_CURRENT,
NULL);
mutex_unlock(&rdev->mutex);
regulator_unlock(rdev);
return IRQ_HANDLED;
}

View File

@ -1153,7 +1153,7 @@ static irqreturn_t pmic_uv_handler(int irq, void *data)
{
struct regulator_dev *rdev = (struct regulator_dev *)data;
mutex_lock(&rdev->mutex);
regulator_lock(rdev);
if (irq == WM8350_IRQ_CS1 || irq == WM8350_IRQ_CS2)
regulator_notifier_call_chain(rdev,
REGULATOR_EVENT_REGULATION_OUT,
@ -1162,7 +1162,7 @@ static irqreturn_t pmic_uv_handler(int irq, void *data)
regulator_notifier_call_chain(rdev,
REGULATOR_EVENT_UNDER_VOLTAGE,
NULL);
mutex_unlock(&rdev->mutex);
regulator_unlock(rdev);
return IRQ_HANDLED;
}

View File

@ -20,6 +20,7 @@
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/regulator/consumer.h>
#include <linux/ww_mutex.h>
struct gpio_desc;
struct regmap;
@ -462,7 +463,7 @@ struct regulator_dev {
struct coupling_desc coupling_desc;
struct blocking_notifier_head notifier;
struct mutex mutex; /* consumer lock */
struct ww_mutex mutex; /* consumer lock */
struct task_struct *mutex_owner;
int ref_cnt;
struct module *owner;
@ -545,4 +546,7 @@ int regulator_set_active_discharge_regmap(struct regulator_dev *rdev,
bool enable);
void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data);
void regulator_lock(struct regulator_dev *rdev);
void regulator_unlock(struct regulator_dev *rdev);
#endif