diff options
Diffstat (limited to 'drivers/regulator/core.c')
| -rw-r--r-- | drivers/regulator/core.c | 214 |
1 files changed, 154 insertions, 60 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 7fd793d8536c..894915892eaf 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -217,6 +217,78 @@ void regulator_unlock(struct regulator_dev *rdev) } EXPORT_SYMBOL_GPL(regulator_unlock); +/** + * regulator_lock_two - lock two regulators + * @rdev1: first regulator + * @rdev2: second regulator + * @ww_ctx: w/w mutex acquire context + * + * Locks both rdevs using the regulator_ww_class. + */ +static void regulator_lock_two(struct regulator_dev *rdev1, + struct regulator_dev *rdev2, + struct ww_acquire_ctx *ww_ctx) +{ + struct regulator_dev *tmp; + int ret; + + ww_acquire_init(ww_ctx, ®ulator_ww_class); + + /* Try to just grab both of them */ + ret = regulator_lock_nested(rdev1, ww_ctx); + WARN_ON(ret); + ret = regulator_lock_nested(rdev2, ww_ctx); + if (ret != -EDEADLOCK) { + WARN_ON(ret); + goto exit; + } + + while (true) { + /* + * Start of loop: rdev1 was locked and rdev2 was contended. + * Need to unlock rdev1, slowly lock rdev2, then try rdev1 + * again. + */ + regulator_unlock(rdev1); + + ww_mutex_lock_slow(&rdev2->mutex, ww_ctx); + rdev2->ref_cnt++; + rdev2->mutex_owner = current; + ret = regulator_lock_nested(rdev1, ww_ctx); + + if (ret == -EDEADLOCK) { + /* More contention; swap which needs to be slow */ + tmp = rdev1; + rdev1 = rdev2; + rdev2 = tmp; + } else { + WARN_ON(ret); + break; + } + } + +exit: + ww_acquire_done(ww_ctx); +} + +/** + * regulator_unlock_two - unlock two regulators + * @rdev1: first regulator + * @rdev2: second regulator + * @ww_ctx: w/w mutex acquire context + * + * The inverse of regulator_lock_two(). + */ + +static void regulator_unlock_two(struct regulator_dev *rdev1, + struct regulator_dev *rdev2, + struct ww_acquire_ctx *ww_ctx) +{ + regulator_unlock(rdev2); + regulator_unlock(rdev1); + ww_acquire_fini(ww_ctx); +} + static bool regulator_supply_is_couple(struct regulator_dev *rdev) { struct regulator_dev *c_rdev; @@ -344,6 +416,7 @@ static void regulator_lock_dependent(struct regulator_dev *rdev, ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); old_contended_rdev = new_contended_rdev; old_contended_rdev->ref_cnt++; + old_contended_rdev->mutex_owner = current; } err = regulator_lock_recursive(rdev, @@ -956,7 +1029,7 @@ static int drms_uA_update(struct regulator_dev *rdev) /* get input voltage */ input_uV = 0; if (rdev->supply) - input_uV = regulator_get_voltage(rdev->supply); + input_uV = regulator_get_voltage_rdev(rdev->supply->rdev); if (input_uV <= 0) input_uV = rdev->constraints->input_uV; if (input_uV <= 0) { @@ -1387,7 +1460,13 @@ static int set_machine_constraints(struct regulator_dev *rdev) if (rdev->supply_name && !rdev->supply) return -EPROBE_DEFER; - if (rdev->supply) { + /* If supplying regulator has already been enabled, + * it's not intended to have use_count increment + * when rdev is only boot-on. + */ + if (rdev->supply && + (rdev->constraints->always_on || + !regulator_is_enabled(rdev->supply))) { ret = regulator_enable(rdev->supply); if (ret < 0) { _regulator_put(rdev->supply); @@ -1412,8 +1491,8 @@ static int set_machine_constraints(struct regulator_dev *rdev) /** * set_supply - set regulator supply regulator - * @rdev: regulator name - * @supply_rdev: supply regulator name + * @rdev: regulator (locked) + * @supply_rdev: supply regulator (locked)) * * Called by platform initialisation code to set the supply regulator for this * regulator. This ensures that a regulators supply will also be enabled by the @@ -1431,6 +1510,7 @@ static int set_supply(struct regulator_dev *rdev, rdev->supply = create_regulator(supply_rdev, &rdev->dev, "SUPPLY"); if (rdev->supply == NULL) { + module_put(supply_rdev->owner); err = -ENOMEM; return err; } @@ -1584,6 +1664,8 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, struct regulator *regulator; int err = 0; + lockdep_assert_held_once(&rdev->mutex.base); + if (dev) { char buf[REG_STR_SIZE]; int size; @@ -1604,16 +1686,14 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, regulator = kzalloc(sizeof(*regulator), GFP_KERNEL); if (regulator == NULL) { - kfree(supply_name); + kfree_const(supply_name); return NULL; } regulator->rdev = rdev; regulator->supply_name = supply_name; - regulator_lock(rdev); list_add(®ulator->list, &rdev->consumer_list); - regulator_unlock(rdev); if (dev) { regulator->dev = dev; @@ -1630,19 +1710,17 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, if (err != -EEXIST) regulator->debugfs = debugfs_create_dir(supply_name, rdev->debugfs); - if (!regulator->debugfs) { + if (IS_ERR(regulator->debugfs)) rdev_dbg(rdev, "Failed to create debugfs directory\n"); - } else { - debugfs_create_u32("uA_load", 0444, regulator->debugfs, - ®ulator->uA_load); - debugfs_create_u32("min_uV", 0444, regulator->debugfs, - ®ulator->voltage[PM_SUSPEND_ON].min_uV); - debugfs_create_u32("max_uV", 0444, regulator->debugfs, - ®ulator->voltage[PM_SUSPEND_ON].max_uV); - debugfs_create_file("constraint_flags", 0444, - regulator->debugfs, regulator, - &constraint_flags_fops); - } + + debugfs_create_u32("uA_load", 0444, regulator->debugfs, + ®ulator->uA_load); + debugfs_create_u32("min_uV", 0444, regulator->debugfs, + ®ulator->voltage[PM_SUSPEND_ON].min_uV); + debugfs_create_u32("max_uV", 0444, regulator->debugfs, + ®ulator->voltage[PM_SUSPEND_ON].max_uV); + debugfs_create_file("constraint_flags", 0444, regulator->debugfs, + regulator, &constraint_flags_fops); /* * Check now if the regulator is an always on regulator - if @@ -1734,6 +1812,7 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev, node = of_get_regulator(dev, supply); if (node) { r = of_find_regulator_by_node(node); + of_node_put(node); if (r) return r; @@ -1778,6 +1857,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) { struct regulator_dev *r; struct device *dev = rdev->dev.parent; + struct ww_acquire_ctx ww_ctx; int ret = 0; /* No supply to resolve? */ @@ -1844,23 +1924,23 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) * between rdev->supply null check and setting rdev->supply in * set_supply() from concurrent tasks. */ - regulator_lock(rdev); + regulator_lock_two(rdev, r, &ww_ctx); /* Supply just resolved by a concurrent task? */ if (rdev->supply) { - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); put_device(&r->dev); goto out; } ret = set_supply(rdev, r); if (ret < 0) { - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); put_device(&r->dev); goto out; } - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); /* * In set_machine_constraints() we may have turned this regulator on @@ -1975,7 +2055,9 @@ struct regulator *_regulator_get(struct device *dev, const char *id, return regulator; } + regulator_lock(rdev); regulator = create_regulator(rdev, dev, id); + regulator_unlock(rdev); if (regulator == NULL) { regulator = ERR_PTR(-ENOMEM); module_put(rdev->owner); @@ -1988,10 +2070,13 @@ struct regulator *_regulator_get(struct device *dev, const char *id, rdev->exclusive = 1; ret = _regulator_is_enabled(rdev); - if (ret > 0) + if (ret > 0) { rdev->use_count = 1; - else + regulator->enable_count = 1; + } else { rdev->use_count = 0; + regulator->enable_count = 0; + } } device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS); @@ -2483,13 +2568,18 @@ static int _regulator_do_enable(struct regulator_dev *rdev) */ static int _regulator_handle_consumer_enable(struct regulator *regulator) { + int ret; struct regulator_dev *rdev = regulator->rdev; lockdep_assert_held_once(&rdev->mutex.base); regulator->enable_count++; - if (regulator->uA_load && regulator->enable_count == 1) - return drms_uA_update(rdev); + if (regulator->uA_load && regulator->enable_count == 1) { + ret = drms_uA_update(rdev); + if (ret) + regulator->enable_count--; + return ret; + } return 0; } @@ -2568,7 +2658,8 @@ static int _regulator_enable(struct regulator *regulator) /* Fallthrough on positive return values - already enabled */ } - rdev->use_count++; + if (regulator->enable_count == 1) + rdev->use_count++; return 0; @@ -2646,37 +2737,40 @@ static int _regulator_disable(struct regulator *regulator) lockdep_assert_held_once(&rdev->mutex.base); - if (WARN(rdev->use_count <= 0, + if (WARN(regulator->enable_count == 0, "unbalanced disables for %s\n", rdev_get_name(rdev))) return -EIO; - /* are we the last user and permitted to disable ? */ - if (rdev->use_count == 1 && - (rdev->constraints && !rdev->constraints->always_on)) { - - /* we are last user */ - if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { - ret = _notifier_call_chain(rdev, - REGULATOR_EVENT_PRE_DISABLE, - NULL); - if (ret & NOTIFY_STOP_MASK) - return -EINVAL; - - ret = _regulator_do_disable(rdev); - if (ret < 0) { - rdev_err(rdev, "failed to disable\n"); - _notifier_call_chain(rdev, - REGULATOR_EVENT_ABORT_DISABLE, + if (regulator->enable_count == 1) { + /* disabling last enable_count from this regulator */ + /* are we the last user and permitted to disable ? */ + if (rdev->use_count == 1 && + (rdev->constraints && !rdev->constraints->always_on)) { + + /* we are last user */ + if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { + ret = _notifier_call_chain(rdev, + REGULATOR_EVENT_PRE_DISABLE, + NULL); + if (ret & NOTIFY_STOP_MASK) + return -EINVAL; + + ret = _regulator_do_disable(rdev); + if (ret < 0) { + rdev_err(rdev, "failed to disable\n"); + _notifier_call_chain(rdev, + REGULATOR_EVENT_ABORT_DISABLE, + NULL); + return ret; + } + _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, NULL); - return ret; } - _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, - NULL); - } - rdev->use_count = 0; - } else if (rdev->use_count > 1) { - rdev->use_count--; + rdev->use_count = 0; + } else if (rdev->use_count > 1) { + rdev->use_count--; + } } if (ret == 0) @@ -4794,6 +4888,7 @@ static void regulator_dev_release(struct device *dev) { struct regulator_dev *rdev = dev_get_drvdata(dev); + debugfs_remove_recursive(rdev->debugfs); kfree(rdev->constraints); of_node_put(rdev->dev.of_node); kfree(rdev); @@ -4813,10 +4908,8 @@ static void rdev_init_debugfs(struct regulator_dev *rdev) } rdev->debugfs = debugfs_create_dir(rname, debugfs_root); - if (!rdev->debugfs) { - rdev_warn(rdev, "Failed to create debugfs directory\n"); - return; - } + if (IS_ERR(rdev->debugfs)) + rdev_dbg(rdev, "Failed to create debugfs directory\n"); debugfs_create_u32("use_count", 0444, rdev->debugfs, &rdev->use_count); @@ -5257,6 +5350,7 @@ unset_supplies: regulator_remove_coupling(rdev); mutex_unlock(®ulator_list_mutex); wash: + regulator_put(rdev->supply); kfree(rdev->coupling_desc.coupled_rdevs); mutex_lock(®ulator_list_mutex); regulator_ena_gpio_free(rdev); @@ -5294,7 +5388,6 @@ void regulator_unregister(struct regulator_dev *rdev) mutex_lock(®ulator_list_mutex); - debugfs_remove_recursive(rdev->debugfs); WARN_ON(rdev->open_count); regulator_remove_coupling(rdev); unset_regulator_supplies(rdev); @@ -5638,6 +5731,7 @@ static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx) ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); old_contended_rdev = new_contended_rdev; old_contended_rdev->ref_cnt++; + old_contended_rdev->mutex_owner = current; } err = regulator_summary_lock_all(ww_ctx, @@ -5698,8 +5792,8 @@ static int __init regulator_init(void) ret = class_register(®ulator_class); debugfs_root = debugfs_create_dir("regulator", NULL); - if (!debugfs_root) - pr_warn("regulator: Failed to create debugfs directory\n"); + if (IS_ERR(debugfs_root)) + pr_debug("regulator: Failed to create debugfs directory\n"); #ifdef CONFIG_DEBUG_FS debugfs_create_file("supply_map", 0444, debugfs_root, NULL, |