From c054c6c792e165de2be51bc3feeaf3cebdedc8d6 Mon Sep 17 00:00:00 2001 From: Maciej Purski Date: Fri, 5 Oct 2018 18:36:28 +0300 Subject: regulator: core: Add voltage balancing mechanism On Odroid XU3/4 and other Exynos5422 based boards there is a case, that different devices on the board are supplied by different regulators with non-fixed voltages. If one of these devices temporarily requires higher voltage, there might occur a situation that the spread between two devices' voltages is so high, that there is a risk of changing 'high' and 'low' states on the interconnection between devices powered by those regulators. Introduce new function regulator_balance_voltage(), which keeps max_spread constraint fulfilled between a group of coupled regulators. It should be called if a regulator changes its voltage or after disabling or enabling. Disabled regulators should follow changes of the enabled ones, but their consumers' demands shouldn't be taken into account while calculating voltage of other coupled regulators. Find voltages, which are closest to suiting all the consumers' demands, while fulfilling max_spread constraint, keeping the following rules: - if one regulator is about to rise its voltage, rise others voltages in order to keep the max_spread - if a regulator, which has caused rising other regulators, is lowered, lower other regulators if possible - if one regulator is about to lower its voltage, but it hasn't caused rising other regulators, change its voltage so that it doesn't break the max_spread Change regulators' voltages step by step, keeping max_spread constraint fulfilled all the time. Function regulator_get_optimal_voltage() should find the best possible change for the regulator, which doesn't break max_spread constraint. In function regulator_balance_voltage() optimize number of steps by finding highest voltage difference on each iteration. If a regulator, which is about to change its voltage, is not coupled, method regulator_get_optimal_voltage() should simply return the lowest voltage fulfilling consumers' demands. Coupling should be checked only if the system is in PM_SUSPEND_ON state. Signed-off-by: Maciej Purski Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 229 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 229 insertions(+) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 2c66b528aede..a2a513780fd7 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -105,6 +105,8 @@ static int _notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data); static int _regulator_do_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV); +static int regulator_balance_voltage(struct regulator_dev *rdev, + suspend_state_t state); static struct regulator *create_regulator(struct regulator_dev *rdev, struct device *dev, const char *supply_name); @@ -3126,6 +3128,233 @@ out2: return ret; } +static int regulator_get_optimal_voltage(struct regulator_dev *rdev, + int *current_uV, + int *min_uV, int *max_uV, + suspend_state_t state, + int n_coupled) +{ + struct coupling_desc *c_desc = &rdev->coupling_desc; + struct regulator_dev **c_rdevs = c_desc->coupled_rdevs; + struct regulation_constraints *constraints = rdev->constraints; + int max_spread = constraints->max_spread; + int desired_min_uV = 0, desired_max_uV = INT_MAX; + int max_current_uV = 0, min_current_uV = INT_MAX; + int highest_min_uV = 0, target_uV, possible_uV; + int i, ret; + bool done; + + *current_uV = -1; + + /* + * If there are no coupled regulators, simply set the voltage + * demanded by consumers. + */ + if (n_coupled == 1) { + /* + * If consumers don't provide any demands, set voltage + * to min_uV + */ + desired_min_uV = constraints->min_uV; + desired_max_uV = constraints->max_uV; + + ret = regulator_check_consumers(rdev, + &desired_min_uV, + &desired_max_uV, state); + if (ret < 0) + return ret; + + possible_uV = desired_min_uV; + done = true; + + goto finish; + } + + /* Find highest min desired voltage */ + for (i = 0; i < n_coupled; i++) { + int tmp_min = 0; + int tmp_max = INT_MAX; + + lockdep_assert_held_once(&c_rdevs[i]->mutex); + + ret = regulator_check_consumers(c_rdevs[i], + &tmp_min, + &tmp_max, state); + if (ret < 0) + return ret; + + ret = regulator_check_voltage(c_rdevs[i], &tmp_min, &tmp_max); + if (ret < 0) + return ret; + + highest_min_uV = max(highest_min_uV, tmp_min); + + if (i == 0) { + desired_min_uV = tmp_min; + desired_max_uV = tmp_max; + } + } + + /* + * Let target_uV be equal to the desired one if possible. + * If not, set it to minimum voltage, allowed by other coupled + * regulators. + */ + target_uV = max(desired_min_uV, highest_min_uV - max_spread); + + /* + * Find min and max voltages, which currently aren't violating + * max_spread. + */ + for (i = 1; i < n_coupled; i++) { + int tmp_act; + + if (!_regulator_is_enabled(c_rdevs[i])) + continue; + + tmp_act = _regulator_get_voltage(c_rdevs[i]); + if (tmp_act < 0) + return tmp_act; + + min_current_uV = min(tmp_act, min_current_uV); + max_current_uV = max(tmp_act, max_current_uV); + } + + /* There aren't any other regulators enabled */ + if (max_current_uV == 0) { + possible_uV = target_uV; + } else { + /* + * Correct target voltage, so as it currently isn't + * violating max_spread + */ + possible_uV = max(target_uV, max_current_uV - max_spread); + possible_uV = min(possible_uV, min_current_uV + max_spread); + } + + if (possible_uV > desired_max_uV) + return -EINVAL; + + done = (possible_uV == target_uV); + desired_min_uV = possible_uV; + +finish: + /* Set current_uV if wasn't done earlier in the code and if necessary */ + if (n_coupled > 1 && *current_uV == -1) { + + if (_regulator_is_enabled(rdev)) { + ret = _regulator_get_voltage(rdev); + if (ret < 0) + return ret; + + *current_uV = ret; + } else { + *current_uV = desired_min_uV; + } + } + + *min_uV = desired_min_uV; + *max_uV = desired_max_uV; + + return done; +} + +static int regulator_balance_voltage(struct regulator_dev *rdev, + suspend_state_t state) +{ + struct regulator_dev **c_rdevs; + struct regulator_dev *best_rdev; + struct coupling_desc *c_desc = &rdev->coupling_desc; + int i, ret, n_coupled, best_min_uV, best_max_uV, best_c_rdev; + bool best_c_rdev_done, c_rdev_done[MAX_COUPLED]; + unsigned int delta, best_delta; + + c_rdevs = c_desc->coupled_rdevs; + n_coupled = c_desc->n_coupled; + + /* + * If system is in a state other than PM_SUSPEND_ON, don't check + * other coupled regulators. + */ + if (state != PM_SUSPEND_ON) + n_coupled = 1; + + if (c_desc->n_resolved < n_coupled) { + rdev_err(rdev, "Not all coupled regulators registered\n"); + return -EPERM; + } + + for (i = 0; i < n_coupled; i++) + c_rdev_done[i] = false; + + /* + * Find the best possible voltage change on each loop. Leave the loop + * if there isn't any possible change. + */ + do { + best_c_rdev_done = false; + best_delta = 0; + best_min_uV = 0; + best_max_uV = 0; + best_c_rdev = 0; + best_rdev = NULL; + + /* + * Find highest difference between optimal voltage + * and current voltage. + */ + for (i = 0; i < n_coupled; i++) { + /* + * optimal_uV is the best voltage that can be set for + * i-th regulator at the moment without violating + * max_spread constraint in order to balance + * the coupled voltages. + */ + int optimal_uV = 0, optimal_max_uV = 0, current_uV = 0; + + if (c_rdev_done[i]) + continue; + + ret = regulator_get_optimal_voltage(c_rdevs[i], + ¤t_uV, + &optimal_uV, + &optimal_max_uV, + state, n_coupled); + if (ret < 0) + goto out; + + delta = abs(optimal_uV - current_uV); + + if (delta && best_delta <= delta) { + best_c_rdev_done = ret; + best_delta = delta; + best_rdev = c_rdevs[i]; + best_min_uV = optimal_uV; + best_max_uV = optimal_max_uV; + best_c_rdev = i; + } + } + + /* Nothing to change, return successfully */ + if (!best_rdev) { + ret = 0; + goto out; + } +#if 0 + ret = regulator_set_voltage_rdev(best_rdev, best_min_uV, + best_max_uV, state); +#endif + if (ret < 0) + goto out; + + c_rdev_done[best_c_rdev] = best_c_rdev_done; + + } while (n_coupled > 1); + +out: + return ret; +} + /** * regulator_set_voltage - set regulator output voltage * @regulator: regulator source -- cgit v1.2.3-59-g8ed1b From 9243a195be7af96a9b69990e9313c4ba1c5fbeca Mon Sep 17 00:00:00 2001 From: Maciej Purski Date: Fri, 5 Oct 2018 18:36:29 +0300 Subject: regulator: core: Change voltage setting path On Odroid XU3/4 and other Exynos5422 based boards there is a case, that different devices on the board are supplied by different regulators with non-fixed voltages. If one of these devices temporarily requires higher voltage, there might occur a situation that the spread between two devices' voltages is so high, that there is a risk of changing 'high' and 'low' states on the interconnection between devices powered by those regulators. Uncoupled regulators should be a special case of coupled regulators, so they should share a common voltage setting path. When enabling, disabling or setting voltage of a coupled regulator, all coupled regulators should be locked. Regulator's supplies should be locked, when setting voltage of a single regulator. Enabling a coupled regulator or setting its voltage should not be possible if some of its coupled regulators, has not been registered. Add function for locking coupled regulators and supplies. Extract a new function regulator_set_voltage_rdev() from regulator_set_voltage_unlocked(), which is called when setting voltage of a single regulator. Signed-off-by: Maciej Purski Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 145 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 99 insertions(+), 46 deletions(-) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index a2a513780fd7..5105eaaf3cef 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -107,6 +107,9 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV); static int regulator_balance_voltage(struct regulator_dev *rdev, suspend_state_t state); +static int regulator_set_voltage_rdev(struct regulator_dev *rdev, + int min_uV, int max_uV, + suspend_state_t state); static struct regulator *create_regulator(struct regulator_dev *rdev, struct device *dev, const char *supply_name); @@ -198,37 +201,66 @@ static void regulator_unlock(struct regulator_dev *rdev) } } -/** - * regulator_lock_supply - lock a regulator and its supplies - * @rdev: regulator source - */ -static void regulator_lock_supply(struct regulator_dev *rdev) +static int regulator_lock_recursive(struct regulator_dev *rdev, + unsigned int subclass) { + struct regulator_dev *c_rdev; int i; - for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++) - regulator_lock_nested(rdev, i); + for (i = 0; i < rdev->coupling_desc.n_coupled; i++) { + c_rdev = rdev->coupling_desc.coupled_rdevs[i]; + + if (!c_rdev) + continue; + + regulator_lock_nested(c_rdev, subclass++); + + if (c_rdev->supply) + subclass = + regulator_lock_recursive(c_rdev->supply->rdev, + subclass); + } + + return subclass; } /** - * regulator_unlock_supply - unlock a regulator and its supplies - * @rdev: regulator source + * regulator_unlock_dependent - unlock regulator's suppliers and coupled + * regulators + * @rdev: regulator source + * + * Unlock all regulators related with rdev by coupling or suppling. */ -static void regulator_unlock_supply(struct regulator_dev *rdev) +static void regulator_unlock_dependent(struct regulator_dev *rdev) { - struct regulator *supply; + struct regulator_dev *c_rdev; + int i; - while (1) { - regulator_unlock(rdev); - supply = rdev->supply; + for (i = 0; i < rdev->coupling_desc.n_coupled; i++) { + c_rdev = rdev->coupling_desc.coupled_rdevs[i]; - if (!rdev->supply) - return; + if (!c_rdev) + continue; - rdev = supply->rdev; + regulator_unlock(c_rdev); + + if (c_rdev->supply) + regulator_unlock_dependent(c_rdev->supply->rdev); } } +/** + * regulator_lock_dependent - lock regulator's suppliers and coupled regulators + * @rdev: regulator source + * + * 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) +{ + regulator_lock_recursive(rdev, 0); +} + /** * of_get_regulator - get a regulator device node based on supply name * @dev: Device pointer for the consumer (of regulator) device @@ -2289,9 +2321,16 @@ int regulator_enable(struct regulator *regulator) return ret; } - mutex_lock(&rdev->mutex); + 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; + } ret = _regulator_enable(rdev); - mutex_unlock(&rdev->mutex); +unlock: + regulator_unlock_dependent(rdev); if (ret != 0 && rdev->supply) regulator_disable(rdev->supply); @@ -2397,9 +2436,11 @@ int regulator_disable(struct regulator *regulator) if (regulator->always_on) return 0; - mutex_lock(&rdev->mutex); + regulator_lock_dependent(rdev); ret = _regulator_disable(rdev); - mutex_unlock(&rdev->mutex); + 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); @@ -2448,10 +2489,12 @@ int regulator_force_disable(struct regulator *regulator) struct regulator_dev *rdev = regulator->rdev; int ret; - mutex_lock(&rdev->mutex); + regulator_lock_dependent(rdev); regulator->uA_load = 0; ret = _regulator_force_disable(regulator->rdev); - mutex_unlock(&rdev->mutex); + if (rdev->coupling_desc.n_coupled > 1) + regulator_balance_voltage(rdev, PM_SUSPEND_ON); + regulator_unlock_dependent(rdev); if (rdev->supply) while (rdev->open_count--) @@ -2599,9 +2642,9 @@ int regulator_is_enabled(struct regulator *regulator) if (regulator->always_on) return 1; - mutex_lock(®ulator->rdev->mutex); + regulator_lock_dependent(regulator->rdev); ret = _regulator_is_enabled(regulator->rdev); - mutex_unlock(®ulator->rdev->mutex); + regulator_unlock_dependent(regulator->rdev); return ret; } @@ -3015,8 +3058,6 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, int ret = 0; int old_min_uV, old_max_uV; int current_uV; - int best_supply_uV = 0; - int supply_change_uV = 0; /* If we're setting the same range as last time the change * should be a noop (some cpufreq implementations use the same @@ -3056,10 +3097,27 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, voltage->min_uV = min_uV; voltage->max_uV = max_uV; - ret = regulator_check_consumers(rdev, &min_uV, &max_uV, state); + /* for not coupled regulators this will just set the voltage */ + ret = regulator_balance_voltage(rdev, state); if (ret < 0) goto out2; +out: + return 0; +out2: + voltage->min_uV = old_min_uV; + voltage->max_uV = old_max_uV; + + return ret; +} + +static int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV, + int max_uV, suspend_state_t state) +{ + int best_supply_uV = 0; + int supply_change_uV = 0; + int ret; + if (rdev->supply && regulator_ops_is_valid(rdev->supply->rdev, REGULATOR_CHANGE_VOLTAGE) && @@ -3071,13 +3129,13 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, selector = regulator_map_voltage(rdev, min_uV, max_uV); if (selector < 0) { ret = selector; - goto out2; + goto out; } best_supply_uV = _regulator_list_voltage(rdev, selector, 0); if (best_supply_uV < 0) { ret = best_supply_uV; - goto out2; + goto out; } best_supply_uV += rdev->desc->min_dropout_uV; @@ -3085,7 +3143,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, current_supply_uV = _regulator_get_voltage(rdev->supply->rdev); if (current_supply_uV < 0) { ret = current_supply_uV; - goto out2; + goto out; } supply_change_uV = best_supply_uV - current_supply_uV; @@ -3097,7 +3155,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, if (ret) { dev_err(&rdev->dev, "Failed to increase supply voltage: %d\n", ret); - goto out2; + goto out; } } @@ -3107,7 +3165,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, ret = _regulator_do_set_suspend_voltage(rdev, min_uV, max_uV, state); if (ret < 0) - goto out2; + goto out; if (supply_change_uV < 0) { ret = regulator_set_voltage_unlocked(rdev->supply, @@ -3120,11 +3178,6 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, } out: - return ret; -out2: - voltage->min_uV = old_min_uV; - voltage->max_uV = old_max_uV; - return ret; } @@ -3340,10 +3393,10 @@ static int regulator_balance_voltage(struct regulator_dev *rdev, ret = 0; goto out; } -#if 0 + ret = regulator_set_voltage_rdev(best_rdev, best_min_uV, best_max_uV, state); -#endif + if (ret < 0) goto out; @@ -3377,12 +3430,12 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV) { int ret = 0; - regulator_lock_supply(regulator->rdev); + regulator_lock_dependent(regulator->rdev); ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV, PM_SUSPEND_ON); - regulator_unlock_supply(regulator->rdev); + regulator_unlock_dependent(regulator->rdev); return ret; } @@ -3460,12 +3513,12 @@ int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV, if (regulator_check_states(state) || state == PM_SUSPEND_ON) return -EINVAL; - regulator_lock_supply(regulator->rdev); + regulator_lock_dependent(regulator->rdev); ret = _regulator_set_suspend_voltage(regulator, min_uV, max_uV, state); - regulator_unlock_supply(regulator->rdev); + regulator_unlock_dependent(regulator->rdev); return ret; } @@ -3657,11 +3710,11 @@ int regulator_get_voltage(struct regulator *regulator) { int ret; - regulator_lock_supply(regulator->rdev); + regulator_lock_dependent(regulator->rdev); ret = _regulator_get_voltage(regulator->rdev); - regulator_unlock_supply(regulator->rdev); + regulator_unlock_dependent(regulator->rdev); return ret; } -- cgit v1.2.3-59-g8ed1b From f9503385b1877ac34514cd5ea7683eee61c4bec3 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Fri, 5 Oct 2018 18:36:30 +0300 Subject: regulator: core: Mutually resolve regulators coupling If registered regulator found a couple, then the couple can find the registered regulator too and hence coupling can be mutually resolved at the registration time. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 54 +++++++++++++++--------------------------------- 1 file changed, 17 insertions(+), 37 deletions(-) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 5105eaaf3cef..925df9e6f1e3 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4439,7 +4439,7 @@ static int regulator_register_resolve_supply(struct device *dev, void *data) return 0; } -static int regulator_fill_coupling_array(struct regulator_dev *rdev) +static void regulator_resolve_coupling(struct regulator_dev *rdev) { struct coupling_desc *c_desc = &rdev->coupling_desc; int n_coupled = c_desc->n_coupled; @@ -4453,33 +4453,21 @@ static int regulator_fill_coupling_array(struct regulator_dev *rdev) c_rdev = of_parse_coupled_regulator(rdev, i - 1); - if (c_rdev) { - c_desc->coupled_rdevs[i] = c_rdev; - c_desc->n_resolved++; - } - } - - if (rdev->coupling_desc.n_resolved < n_coupled) - return -1; - else - return 0; -} + if (!c_rdev) + continue; -static int regulator_register_fill_coupling_array(struct device *dev, - void *data) -{ - struct regulator_dev *rdev = dev_to_rdev(dev); + regulator_lock(c_rdev); - if (!IS_ENABLED(CONFIG_OF)) - return 0; + c_desc->coupled_rdevs[i] = c_rdev; + c_desc->n_resolved++; - if (regulator_fill_coupling_array(rdev)) - rdev_dbg(rdev, "unable to resolve coupling\n"); + regulator_unlock(c_rdev); - return 0; + regulator_resolve_coupling(c_rdev); + } } -static int regulator_resolve_coupling(struct regulator_dev *rdev) +static int regulator_init_coupling(struct regulator_dev *rdev) { int n_phandles; @@ -4519,13 +4507,6 @@ static int regulator_resolve_coupling(struct regulator_dev *rdev) if (!of_check_coupling_data(rdev)) return -EPERM; - /* - * After everything has been checked, try to fill rdevs array - * with pointers to regulators parsed from device tree. If some - * regulators are not registered yet, retry in late init call - */ - regulator_fill_coupling_array(rdev); - return 0; } @@ -4662,11 +4643,8 @@ regulator_register(const struct regulator_desc *regulator_desc, if (ret < 0) goto wash; - mutex_lock(®ulator_list_mutex); - ret = regulator_resolve_coupling(rdev); - mutex_unlock(®ulator_list_mutex); - - if (ret != 0) + ret = regulator_init_coupling(rdev); + if (ret < 0) goto wash; /* add consumers devices */ @@ -4700,6 +4678,11 @@ regulator_register(const struct regulator_desc *regulator_desc, rdev_init_debugfs(rdev); + /* try to resolve regulators coupling since a new one was registered */ + mutex_lock(®ulator_list_mutex); + regulator_resolve_coupling(rdev); + mutex_unlock(®ulator_list_mutex); + /* try to resolve regulators supply since a new one was registered */ class_for_each_device(®ulator_class, NULL, NULL, regulator_register_resolve_supply); @@ -5155,9 +5138,6 @@ static int __init regulator_init_complete(void) class_for_each_device(®ulator_class, NULL, NULL, regulator_late_cleanup); - class_for_each_device(®ulator_class, NULL, NULL, - regulator_register_fill_coupling_array); - return 0; } late_initcall_sync(regulator_init_complete); -- cgit v1.2.3-59-g8ed1b From 79d6f049f4f05f5cb6e1647a9a253dad14bfabbe Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Fri, 5 Oct 2018 18:36:31 +0300 Subject: regulator: core: Don't allow to get regulator until all couples resolved Don't allow to get regulator until all of its couples resolved because consumer will get EPERM and coupling shall be transparent for the drivers. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 925df9e6f1e3..089e8ad8ef57 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1747,6 +1747,16 @@ struct regulator *_regulator_get(struct device *dev, const char *id, return regulator; } + mutex_lock(®ulator_list_mutex); + ret = (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled); + mutex_unlock(®ulator_list_mutex); + + if (ret != 0) { + regulator = ERR_PTR(-EPROBE_DEFER); + put_device(&rdev->dev); + return regulator; + } + ret = regulator_resolve_supply(rdev); if (ret < 0) { regulator = ERR_PTR(ret); -- cgit v1.2.3-59-g8ed1b From 85254bcf394f93a8955814da1eef4d477b63eb84 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Fri, 5 Oct 2018 18:36:35 +0300 Subject: regulator: core: Add new max_uV_step constraint On NVIDIA Tegra30 there is a requirement for regulator "A" to have voltage higher than voltage of regulator "B" by N microvolts, the N value changes depending on the voltage of regulator "B". This is similar to min-spread between voltages of regulators, the difference is that the spread value isn't fixed. This means that extra carefulness is required for regulator "A" to drop its voltage without violating the requirement, hence its voltage should be changed in steps so that its couple "B" could follow (there is also max-spread requirement). Add new "max_uV_step" constraint that breaks voltage change into several steps, each step is limited by the max_uV_step value. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 41 +++++++++++++++++++++++++++++++++++++++ drivers/regulator/of_regulator.c | 4 ++++ include/linux/regulator/machine.h | 3 +++ 3 files changed, 48 insertions(+) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 089e8ad8ef57..ba03bdf3716f 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -3191,6 +3191,36 @@ out: return ret; } +static int regulator_limit_voltage_step(struct regulator_dev *rdev, + int *current_uV, int *min_uV) +{ + struct regulation_constraints *constraints = rdev->constraints; + + /* Limit voltage change only if necessary */ + if (!constraints->max_uV_step || !_regulator_is_enabled(rdev)) + return 1; + + if (*current_uV < 0) { + *current_uV = _regulator_get_voltage(rdev); + + if (*current_uV < 0) + return *current_uV; + } + + if (abs(*current_uV - *min_uV) <= constraints->max_uV_step) + return 1; + + /* Clamp target voltage within the given step */ + if (*current_uV < *min_uV) + *min_uV = min(*current_uV + constraints->max_uV_step, + *min_uV); + else + *min_uV = max(*current_uV - constraints->max_uV_step, + *min_uV); + + return 0; +} + static int regulator_get_optimal_voltage(struct regulator_dev *rdev, int *current_uV, int *min_uV, int *max_uV, @@ -3302,6 +3332,17 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev, desired_min_uV = possible_uV; finish: + /* Apply max_uV_step constraint if necessary */ + if (state == PM_SUSPEND_ON) { + ret = regulator_limit_voltage_step(rdev, current_uV, + &desired_min_uV); + if (ret < 0) + return ret; + + if (ret == 0) + done = false; + } + /* Set current_uV if wasn't done earlier in the code and if necessary */ if (n_coupled > 1 && *current_uV == -1) { diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index c4223b3e0dff..a732f09d207b 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -170,6 +170,10 @@ static void of_get_regulation_constraints(struct device_node *np, &pval)) constraints->max_spread = pval; + if (!of_property_read_u32(np, "regulator-max-step-microvolt", + &pval)) + constraints->max_uV_step = pval; + constraints->over_current_protection = of_property_read_bool(np, "regulator-over-current-protection"); diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index a459a5e973a7..1d34a70ffda2 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -158,6 +158,9 @@ struct regulation_constraints { /* used for coupled regulators */ int max_spread; + /* used for changing voltage in steps */ + int max_uV_step; + /* valid regulator operating modes for this machine */ unsigned int valid_modes_mask; -- cgit v1.2.3-59-g8ed1b From 6303f3e78b6fd3f84dbe7f2fa4f108d47061d1fb Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Fri, 5 Oct 2018 18:36:36 +0300 Subject: regulator: core: Decouple regulators on regulator_unregister() Regulators shall be uncoupled if one of the couples disappear. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index ba03bdf3716f..783ec9c74104 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4518,6 +4518,43 @@ static void regulator_resolve_coupling(struct regulator_dev *rdev) } } +static void regulator_remove_coupling(struct regulator_dev *rdev) +{ + struct coupling_desc *__c_desc, *c_desc = &rdev->coupling_desc; + struct regulator_dev *__c_rdev, *c_rdev; + unsigned int __n_coupled, n_coupled; + int i, k; + + n_coupled = c_desc->n_coupled; + + for (i = 1; i < n_coupled; i++) { + c_rdev = c_desc->coupled_rdevs[i]; + + if (!c_rdev) + continue; + + regulator_lock(c_rdev); + + __c_desc = &c_rdev->coupling_desc; + __n_coupled = __c_desc->n_coupled; + + for (k = 1; k < __n_coupled; k++) { + __c_rdev = __c_desc->coupled_rdevs[k]; + + if (__c_rdev == rdev) { + __c_desc->coupled_rdevs[k] = NULL; + __c_desc->n_resolved--; + break; + } + } + + regulator_unlock(c_rdev); + + c_desc->coupled_rdevs[i] = NULL; + c_desc->n_resolved--; + } +} + static int regulator_init_coupling(struct regulator_dev *rdev) { int n_phandles; @@ -4776,6 +4813,7 @@ void regulator_unregister(struct regulator_dev *rdev) debugfs_remove_recursive(rdev->debugfs); flush_work(&rdev->disable_work.work); WARN_ON(rdev->open_count); + regulator_remove_coupling(rdev); unset_regulator_supplies(rdev); list_del(&rdev->list); regulator_ena_gpio_free(rdev); -- cgit v1.2.3-59-g8ed1b From f8702f9e4aa7b45131af3df5531d6e3835269141 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 19 Nov 2018 00:56:17 +0300 Subject: 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 Suggested-by: Lucas Stach Signed-off-by: Mark Brown --- drivers/regulator/core.c | 403 ++++++++++++++++++++++++++-------- drivers/regulator/da9210-regulator.c | 4 +- drivers/regulator/stpmic1_regulator.c | 4 +- drivers/regulator/wm8350-regulator.c | 4 +- include/linux/regulator/driver.h | 6 +- 5 files changed, 317 insertions(+), 104 deletions(-) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 783ec9c74104..47ccd35c7965 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -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(®ulator_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(®ulator_nesting_mutex); + ret = ww_mutex_lock(&rdev->mutex, ww_ctx); + mutex_lock(®ulator_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(®ulator_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); } /** @@ -189,52 +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(®ulator_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(®ulator_nesting_mutex); } -static int regulator_lock_recursive(struct regulator_dev *rdev, - unsigned int subclass) +static void regulator_unlock_recursive(struct regulator_dev *rdev, + unsigned int n_coupled) { 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]; + for (i = n_coupled; i > 0; i--) { + c_rdev = rdev->coupling_desc.coupled_rdevs[i - 1]; if (!c_rdev) continue; - regulator_lock_nested(c_rdev, subclass++); - if (c_rdev->supply) - subclass = - regulator_lock_recursive(c_rdev->supply->rdev, - subclass); - } + regulator_unlock_recursive( + c_rdev->supply->rdev, + c_rdev->coupling_desc.n_coupled); - return subclass; + regulator_unlock(c_rdev); + } } -/** - * regulator_unlock_dependent - unlock regulator's suppliers and coupled - * regulators - * @rdev: regulator source - * - * Unlock all regulators related with rdev by coupling or suppling. - */ -static void regulator_unlock_dependent(struct regulator_dev *rdev) +static int regulator_lock_recursive(struct regulator_dev *rdev, + 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]; @@ -242,23 +268,95 @@ static void regulator_unlock_dependent(struct regulator_dev *rdev) if (!c_rdev) continue; - regulator_unlock(c_rdev); + 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) - regulator_unlock_dependent(c_rdev->supply->rdev); + /* 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 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, + struct ww_acquire_ctx *ww_ctx) +{ + 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(®ulator_list_mutex); + + ww_acquire_init(ww_ctx, ®ulator_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(®ulator_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, ®ulator_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(®ulator_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(®ulator_class, NULL, &lock_data, + regulator_summary_lock_one); + if (ret) + class_for_each_device(®ulator_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, ®ulator_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(®ulator_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(®ulator_class, NULL, s, regulator_summary_show_roots); + regulator_summary_unlock(&ww_ctx); + return 0; } diff --git a/drivers/regulator/da9210-regulator.c b/drivers/regulator/da9210-regulator.c index d0496d6b0934..84dba64ed11e 100644 --- a/drivers/regulator/da9210-regulator.c +++ b/drivers/regulator/da9210-regulator.c @@ -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 */ diff --git a/drivers/regulator/stpmic1_regulator.c b/drivers/regulator/stpmic1_regulator.c index e15634edb8ce..eac0848a78c7 100644 --- a/drivers/regulator/stpmic1_regulator.c +++ b/drivers/regulator/stpmic1_regulator.c @@ -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; } diff --git a/drivers/regulator/wm8350-regulator.c b/drivers/regulator/wm8350-regulator.c index 8ad11b074b49..a1c7dfee5c37 100644 --- a/drivers/regulator/wm8350-regulator.c +++ b/drivers/regulator/wm8350-regulator.c @@ -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; } diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index a05d37d0efa1..7065031f0846 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -20,6 +20,7 @@ #include #include #include +#include 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 -- cgit v1.2.3-59-g8ed1b From 089e2cc2e1861ad13a56811aa538419989346089 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 19 Nov 2018 00:56:18 +0300 Subject: regulator: core: Properly handle case where supply is the couple Check whether supply regulator is the couple to avoid infinite recursion during of locking. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 47ccd35c7965..e46e53aa43db 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -233,6 +233,21 @@ void regulator_unlock(struct regulator_dev *rdev) mutex_unlock(®ulator_nesting_mutex); } +static bool regulator_supply_is_couple(struct regulator_dev *rdev) +{ + struct regulator_dev *c_rdev; + int i; + + for (i = 1; i < rdev->coupling_desc.n_coupled; i++) { + c_rdev = rdev->coupling_desc.coupled_rdevs[i]; + + if (rdev->supply->rdev == c_rdev) + return true; + } + + return false; +} + static void regulator_unlock_recursive(struct regulator_dev *rdev, unsigned int n_coupled) { @@ -245,7 +260,7 @@ static void regulator_unlock_recursive(struct regulator_dev *rdev, if (!c_rdev) continue; - if (c_rdev->supply) + if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) regulator_unlock_recursive( c_rdev->supply->rdev, c_rdev->coupling_desc.n_coupled); @@ -283,7 +298,7 @@ static int regulator_lock_recursive(struct regulator_dev *rdev, *old_contended_rdev = NULL; } - if (c_rdev->supply) { + if (c_rdev->supply && !regulator_supply_is_couple(c_rdev)) { err = regulator_lock_recursive(c_rdev->supply->rdev, new_contended_rdev, old_contended_rdev, -- cgit v1.2.3-59-g8ed1b From ff9b34b615a37a3f4d359bf82fc97f5e0310b301 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 19 Nov 2018 00:56:19 +0300 Subject: regulator: core: Keep regulators-list locked while traversing the list It's unlikely that regulators may disappear/appear while regulators debug-summary is being prepared, but let's be consistent and avoid that situation. Signed-off-by: Dmitry Osipenko Signed-off-by: Mark Brown --- drivers/regulator/core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/regulator/core.c') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index e46e53aa43db..fd237bc0fa7c 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4936,7 +4936,9 @@ void regulator_unregister(struct regulator_dev *rdev) regulator_disable(rdev->supply); regulator_put(rdev->supply); } + mutex_lock(®ulator_list_mutex); + debugfs_remove_recursive(rdev->debugfs); flush_work(&rdev->disable_work.work); WARN_ON(rdev->open_count); @@ -4944,8 +4946,9 @@ void regulator_unregister(struct regulator_dev *rdev) unset_regulator_supplies(rdev); list_del(&rdev->list); regulator_ena_gpio_free(rdev); - mutex_unlock(®ulator_list_mutex); device_unregister(&rdev->dev); + + mutex_unlock(®ulator_list_mutex); } EXPORT_SYMBOL_GPL(regulator_unregister); @@ -5278,6 +5281,8 @@ static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx) struct regulator_dev *old_contended_rdev = NULL; int err; + mutex_lock(®ulator_list_mutex); + ww_acquire_init(ww_ctx, ®ulator_ww_class); do { @@ -5304,6 +5309,8 @@ static void regulator_summary_unlock(struct ww_acquire_ctx *ww_ctx) class_for_each_device(®ulator_class, NULL, NULL, regulator_summary_unlock_one); ww_acquire_fini(ww_ctx); + + mutex_unlock(®ulator_list_mutex); } static int regulator_summary_show_roots(struct device *dev, void *data) -- cgit v1.2.3-59-g8ed1b