@@ -4,7 +4,7 @@
#
-obj-$(CONFIG_REGULATOR) += core.o dummy.o fixed-helper.o helpers.o devres.o
+obj-$(CONFIG_REGULATOR) += core.o dummy.o fixed-helper.o helpers.o devres.o irq_helpers.o
obj-$(CONFIG_OF) += of_regulator.o
obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o
obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o
@@ -4380,22 +4380,36 @@ unsigned int regulator_get_mode(struct regulator *regulator)
}
EXPORT_SYMBOL_GPL(regulator_get_mode);
+static int rdev_get_cached_err_flags(struct regulator_dev *rdev)
+{
+ int ret = 0;
+
+ if (rdev->use_cached_err) {
+ spin_lock(&rdev->err_lock);
+ ret = rdev->cached_err;
+ spin_unlock(&rdev->err_lock);
+ }
+ return ret;
+}
+
static int _regulator_get_error_flags(struct regulator_dev *rdev,
unsigned int *flags)
{
- int ret;
+ int cached_flags, ret = 0;
regulator_lock(rdev);
- /* sanity check */
- if (!rdev->desc->ops->get_error_flags) {
+ cached_flags = rdev_get_cached_err_flags(rdev);
+
+ if (rdev->desc->ops->get_error_flags)
+ ret = rdev->desc->ops->get_error_flags(rdev, flags);
+ else if (!rdev->use_cached_err)
ret = -EINVAL;
- goto out;
- }
- ret = rdev->desc->ops->get_error_flags(rdev, flags);
-out:
+ *flags |= cached_flags;
+
regulator_unlock(rdev);
+
return ret;
}
@@ -5228,6 +5242,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
goto rinse;
}
device_initialize(&rdev->dev);
+ spin_lock_init(&rdev->err_lock);
/*
* Duplicate the config so the driver could override it after
@@ -481,3 +481,55 @@ void devm_regulator_unregister_notifier(struct regulator *regulator,
WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_regulator_unregister_notifier);
+
+static void regulator_irq_helper_drop(void *res)
+{
+ regulator_irq_helper_cancel(&res);
+}
+
+/**
+ * devm_regulator_irq_helper - resource managed registration of IRQ based
+ * regulator event/error notifier
+ *
+ * @dev: device to which lifetime the helper's lifetime is
+ * bound.
+ * @d: IRQ helper descriptor.
+ * @irq: IRQ used to inform events/errors to be notified.
+ * @irq_flags: Extra IRQ flags to be OR'ed with the default
+ * IRQF_ONESHOT when requesting the (threaded) irq.
+ * @common_errs: Errors which can be flagged by this IRQ for all rdevs.
+ * When IRQ is re-enabled these errors will be cleared
+ * from all associated regulators
+ * @per_rdev_errs: Optional error flag array describing errors specific
+ * for only some of the regulators. These errors will be
+ * or'ed with common errors. If this is given the array
+ * should contain rdev_amount flags. Can be set to NULL
+ * if there is no regulator specific error flags for this
+ * IRQ.
+ * @rdev: Array of pointers to regulators associated with this
+ * IRQ.
+ * @rdev_amount: Amount of regulators associated with this IRQ.
+ *
+ * Return: handle to irq_helper or an ERR_PTR() encoded error code.
+ */
+void *devm_regulator_irq_helper(struct device *dev,
+ const struct regulator_irq_desc *d, int irq,
+ int irq_flags, int common_errs,
+ int *per_rdev_errs,
+ struct regulator_dev **rdev, int rdev_amount)
+{
+ void *ptr;
+ int ret;
+
+ ptr = regulator_irq_helper(dev, d, irq, irq_flags, common_errs,
+ per_rdev_errs, rdev, rdev_amount);
+ if (IS_ERR(ptr))
+ return ptr;
+
+ ret = devm_add_action_or_reset(dev, regulator_irq_helper_drop, ptr);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(devm_regulator_irq_helper);
new file mode 100644
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2021 ROHM Semiconductors
+// regulator IRQ based event notification helpers
+//
+// Logic has been partially adapted from qcom-labibb driver.
+//
+// Author: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/regulator/driver.h>
+
+#define REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS 10000
+
+struct regulator_irq {
+ struct regulator_irq_data rdata;
+ struct regulator_irq_desc desc;
+ int irq;
+ int retry_cnt;
+ struct delayed_work isr_work;
+};
+
+/*
+ * Should only be called from threaded handler to prevent potential deadlock
+ */
+static void rdev_flag_err(struct regulator_dev *rdev, int err)
+{
+ spin_lock(&rdev->err_lock);
+ rdev->cached_err |= err;
+ spin_unlock(&rdev->err_lock);
+}
+
+static void rdev_clear_err(struct regulator_dev *rdev, int err)
+{
+ spin_lock(&rdev->err_lock);
+ rdev->cached_err &= ~err;
+ spin_unlock(&rdev->err_lock);
+}
+
+static void regulator_notifier_isr_work(struct work_struct *work)
+{
+ struct regulator_irq *h;
+ struct regulator_irq_desc *d;
+ struct regulator_irq_data *rid;
+ int ret = 0;
+ int tmo, i;
+ int num_rdevs;
+
+ h = container_of(work, struct regulator_irq,
+ isr_work.work);
+ d = &h->desc;
+ rid = &h->rdata;
+ num_rdevs = rid->num_states;
+
+reread:
+ if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) {
+ if (!d->die)
+ return hw_protection_shutdown("Regulator HW failure? - no IC recovery",
+ REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+ ret = d->die(rid);
+ /*
+ * If the 'last resort' IC recovery failed we will have
+ * nothing else left to do...
+ */
+ if (ret)
+ return hw_protection_shutdown("Regulator HW failure. IC recovery failed",
+ REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+
+ /*
+ * If h->die() was implemented we assume recovery has been
+ * attempted (probably regulator was shut down) and we
+ * just enable IRQ and bail-out.
+ */
+ goto enable_out;
+ }
+ if (d->renable) {
+ ret = d->renable(rid);
+
+ if (ret == REGULATOR_FAILED_RETRY) {
+ /* Driver could not get current status */
+ h->retry_cnt++;
+ if (!d->reread_ms)
+ goto reread;
+
+ tmo = d->reread_ms;
+ goto reschedule;
+ }
+
+ if (ret) {
+ /*
+ * IC status reading succeeded. update error info
+ * just in case the renable changed it.
+ */
+ for (i = 0; i < num_rdevs; i++) {
+ struct regulator_err_state *stat;
+ struct regulator_dev *rdev;
+
+ stat = &rid->states[i];
+ rdev = stat->rdev;
+ rdev_clear_err(rdev, (~stat->errors) &
+ stat->possible_errs);
+ }
+ h->retry_cnt++;
+ /*
+ * The IC indicated problem is still ON - no point in
+ * re-enabling the IRQ. Retry later.
+ */
+ tmo = d->irq_off_ms;
+ goto reschedule;
+ }
+ }
+
+ /*
+ * Either IC reported problem cleared or no status checker was provided.
+ * If problems are gone - good. If not - then the IRQ will fire again
+ * and we'll have a new nice loop. In any case we should clear error
+ * flags here and re-enable IRQs.
+ */
+ for (i = 0; i < num_rdevs; i++) {
+ struct regulator_err_state *stat;
+ struct regulator_dev *rdev;
+
+ stat = &rid->states[i];
+ rdev = stat->rdev;
+ rdev_clear_err(rdev, stat->possible_errs);
+ }
+
+ /*
+ * Things have been seemingly successful => zero retry-counter.
+ */
+ h->retry_cnt = 0;
+
+enable_out:
+ enable_irq(h->irq);
+
+ return;
+
+reschedule:
+ if (!d->high_prio)
+ mod_delayed_work(system_wq, &h->isr_work,
+ msecs_to_jiffies(tmo));
+ else
+ mod_delayed_work(system_highpri_wq, &h->isr_work,
+ msecs_to_jiffies(tmo));
+}
+
+static irqreturn_t regulator_notifier_isr(int irq, void *data)
+{
+ struct regulator_irq *h = data;
+ struct regulator_irq_desc *d;
+ struct regulator_irq_data *rid;
+ unsigned long rdev_map = 0;
+ int num_rdevs;
+ int ret, i, j;
+
+ d = &h->desc;
+ rid = &h->rdata;
+ num_rdevs = rid->num_states;
+
+ if (d->fatal_cnt)
+ h->retry_cnt++;
+
+ /*
+ * we spare a few cycles by not clearing statuses prior to this call.
+ * The IC driver must initialize the status buffers for rdevs
+ * which it indicates having active events via rdev_map.
+ *
+ * Maybe we should just to be on a safer side(?)
+ */
+ ret = d->map_event(irq, rid, &rdev_map);
+
+ /*
+ * If status reading fails (which is unlikely) we don't ack/disable
+ * IRQ but just increase fail count and retry when IRQ fires again.
+ * If retry_count exceeds the given safety limit we call IC specific die
+ * handler which can try disabling regulator(s).
+ *
+ * If no die handler is given we will just bug() as a last resort.
+ *
+ * We could try disabling all associated rdevs - but we might shoot
+ * ourselves in the head and leave the problematic regulator enabled. So
+ * if IC has no die-handler populated we just assume the regulator
+ * can't be disabled.
+ */
+ if (unlikely(ret == REGULATOR_FAILED_RETRY))
+ goto fail_out;
+
+ h->retry_cnt = 0;
+ /*
+ * Let's not disable IRQ if there were no status bits for us. We'd
+ * better leave spurious IRQ handling to genirq
+ */
+ if (ret || !rdev_map)
+ return IRQ_NONE;
+
+ /*
+ * Some events are bogus if the regulator is disabled. Skip such events
+ * if all relevant regulators are disabled
+ */
+ if (d->skip_off) {
+ for_each_set_bit(i, &rdev_map, num_rdevs) {
+ struct regulator_dev *rdev;
+ const struct regulator_ops *ops;
+
+ rdev = rid->states[i].rdev;
+ ops = rdev->desc->ops;
+
+ /*
+ * If any of the flagged regulators is enabled we do
+ * handle this
+ */
+ if (ops->is_enabled(rdev))
+ break;
+ }
+ if (i == num_rdevs)
+ return IRQ_NONE;
+ }
+
+ /* Disable IRQ if HW keeps line asserted */
+ if (d->irq_off_ms)
+ disable_irq_nosync(irq);
+
+ /*
+ * IRQ seems to be for us. Let's fire correct notifiers / store error
+ * flags
+ */
+ for_each_set_bit(i, &rdev_map, num_rdevs) {
+ unsigned long evt;
+ struct regulator_err_state *stat;
+ struct regulator_dev *rdev;
+
+ stat = &rid->states[i];
+ rdev = stat->rdev;
+
+ for_each_set_bit(j, &stat->notifs, BITS_PER_TYPE(stat->notifs))
+ evt = BIT(j);
+ pr_dbg("Sending regulator notification EVT 0x%lx\r\n",
+ stat->notifs, evt);
+ regulator_notifier_call_chain(rdev, evt, NULL);
+
+ rdev_flag_err(rdev, stat->errors);
+ }
+
+ if (d->irq_off_ms) {
+ if (!d->high_prio)
+ schedule_delayed_work(&h->isr_work,
+ msecs_to_jiffies(d->irq_off_ms));
+ else
+ mod_delayed_work(system_highpri_wq,
+ &h->isr_work,
+ msecs_to_jiffies(d->irq_off_ms));
+ }
+
+ return IRQ_HANDLED;
+
+fail_out:
+ if (d->fatal_cnt && h->retry_cnt > d->fatal_cnt) {
+ /* If we have no recovery, just try shut down straight away */
+ if (!d->die) {
+ hw_protection_shutdown("Regulator failure. Retry count exceeded",
+ REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+ } else {
+ ret = d->die(rid);
+ /* If die() failed shut down as a last attempt to save the HW */
+ if (ret)
+ hw_protection_shutdown("Regulator failure. Recovery failed",
+ REGULATOR_FORCED_SAFETY_SHUTDOWN_WAIT_MS);
+ }
+ }
+
+ return IRQ_NONE;
+}
+
+static int init_rdev_state(struct device *dev, struct regulator_irq *h,
+ struct regulator_dev **rdev, int common_err,
+ int *rdev_err, int rdev_amount)
+{
+ int i;
+
+ h->rdata.states = devm_kzalloc(dev, sizeof(*h->rdata.states) *
+ rdev_amount, GFP_KERNEL);
+ if (!h->rdata.states)
+ return -ENOMEM;
+
+ h->rdata.num_states = rdev_amount;
+ h->rdata.data = h->desc.data;
+
+ for (i = 0; i < rdev_amount; i++) {
+ h->rdata.states[i].possible_errs = common_err;
+ if (rdev_err)
+ h->rdata.states[i].possible_errs |= *rdev_err++;
+ h->rdata.states[i].rdev = *rdev++;
+ }
+
+ return 0;
+}
+
+static void init_rdev_errors(struct regulator_irq *h)
+{
+ int i;
+
+ for (i = 0; i < h->rdata.num_states; i++)
+ if (h->rdata.states[i].possible_errs)
+ h->rdata.states[i].rdev->use_cached_err = true;
+}
+
+/**
+ * regulator_irq_helper - register IRQ based regulator event/error notifier
+ *
+ * @dev: device providing the IRQs
+ * @d: IRQ helper descriptor.
+ * @irq: IRQ used to inform events/errors to be notified.
+ * @irq_flags: Extra IRQ flags to be OR'ed with the default
+ * IRQF_ONESHOT when requesting the (threaded) irq.
+ * @common_errs: Errors which can be flagged by this IRQ for all rdevs.
+ * When IRQ is re-enabled these errors will be cleared
+ * from all associated regulators
+ * @per_rdev_errs: Optional error flag array describing errors specific
+ * for only some of the regulators. These errors will be
+ * or'ed with common errors. If this is given the array
+ * should contain rdev_amount flags. Can be set to NULL
+ * if there is no regulator specific error flags for this
+ * IRQ.
+ * @rdev: Array of pointers to regulators associated with this
+ * IRQ.
+ * @rdev_amount: Amount of regulators associated with this IRQ.
+ *
+ * Return: handle to irq_helper or an ERR_PTR() encoded error code.
+ */
+void *regulator_irq_helper(struct device *dev,
+ const struct regulator_irq_desc *d, int irq,
+ int irq_flags, int common_errs, int *per_rdev_errs,
+ struct regulator_dev **rdev, int rdev_amount)
+{
+ struct regulator_irq *h;
+ int ret;
+
+ if (!rdev_amount || !d || !d->map_event || !d->name)
+ return ERR_PTR(-EINVAL);
+
+ h = devm_kzalloc(dev, sizeof(*h), GFP_KERNEL);
+ if (!h)
+ return ERR_PTR(-ENOMEM);
+
+ h->irq = irq;
+ h->desc = *d;
+
+ ret = init_rdev_state(dev, h, rdev, common_errs, per_rdev_errs,
+ rdev_amount);
+ if (ret)
+ return ERR_PTR(ret);
+
+ init_rdev_errors(h);
+
+ if (h->desc.irq_off_ms)
+ INIT_DELAYED_WORK(&h->isr_work, regulator_notifier_isr_work);
+
+ ret = request_threaded_irq(h->irq, NULL, regulator_notifier_isr,
+ IRQF_ONESHOT | irq_flags, h->desc.name, h);
+ if (ret) {
+ dev_err(dev, "Failed to request IRQ %d\n", irq);
+
+ return ERR_PTR(ret);
+ }
+
+ return h;
+}
+EXPORT_SYMBOL_GPL(regulator_irq_helper);
+
+/**
+ * regulator_irq_helper_cancel - drop IRQ based regulator event/error notifier
+ *
+ * @handle: Pointer to handle returned by a successful call to
+ * regulator_irq_helper(). Will be NULLed upon return.
+ *
+ * The associated IRQ is released and work is cancelled when the function
+ * returns.
+ */
+void regulator_irq_helper_cancel(void **handle)
+{
+ if (handle && *handle) {
+ struct regulator_irq *h = *handle;
+
+ free_irq(h->irq, h);
+ if (h->desc.irq_off_ms)
+ cancel_delayed_work_sync(&h->isr_work);
+
+ h = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(regulator_irq_helper_cancel);
@@ -413,6 +413,128 @@ struct regulator_config {
struct gpio_desc *ena_gpiod;
};
+/**
+ * struct regulator_err_state - regulator error/notification status
+ *
+ * @rdev: Regulator which status the struct indicates.
+ * @notifs: Events which have occurred on the regulator.
+ * @errors: Errors which are active on the regulator.
+ * @possible_errs: Errors which can be signaled (by given IRQ).
+ */
+struct regulator_err_state {
+ struct regulator_dev *rdev;
+ unsigned long notifs;
+ unsigned long errors;
+ int possible_errs;
+};
+
+/**
+ * struct regulator_irq_data - regulator error/notification status date
+ *
+ * @states: Status structs for each of the associated regulators.
+ * @num_states: Amount of associated regulators.
+ * @data: Driver data pointer given at regulator_irq_desc.
+ * @opaque: Value storage for IC driver. Core does not update this. ICs
+ * may want to store status register value here at map_event and
+ * compare contents at 'renable' callback to see if new problems
+ * have been added to status. If that is the case it may be
+ * desirable to return REGULATOR_ERROR_CLEARED and not
+ * REGULATOR_ERROR_ON to allow IRQ fire again and to generate
+ * notifications also for the new issues.
+ *
+ * This structure is passed to 'map_event' and 'renable' callbacks for
+ * reporting regulator status to core.
+ */
+struct regulator_irq_data {
+ struct regulator_err_state *states;
+ int num_states;
+ void *data;
+ long opaque;
+};
+
+/**
+ * struct regulator_irq_desc - notification sender for IRQ based events.
+ *
+ * @name: The visible name for the IRQ
+ * @fatal_cnt: If this IRQ is used to signal HW damaging condition it may be
+ * best to shut-down regulator(s) or reboot the SOC if error
+ * handling is repeatedly failing. If fatal_cnt is given the IRQ
+ * handling is aborted if it fails for fatal_cnt times and die()
+ * callback (if populated) or BUG() is called to try to prevent
+ * further damage.
+ * @reread_ms: The time which is waited before attempting to re-read status
+ * at the worker if IC reading fails. Immediate re-read is done
+ * if time is not specified.
+ * @irq_off_ms: The time which IRQ is kept disabled before re-evaluating the
+ * status for devices which keep IRQ disabled for duration of the
+ * error. If this is not given the IRQ is left enabled and renable
+ * is not called.
+ * @skip_off: If set to true the IRQ handler will attempt to check if any of
+ * the associated regulators are enabled prior to taking other
+ * actions. If no regulators are enabled and this is set to true
+ * a spurious IRQ is assumed and IRQ_NONE is returned.
+ * @high_prio: Boolean to indicate that high priority WQ should be used.
+ * @data: Driver private data pointer which will be passed as such to
+ * the renable, map_event and die callbacks in regulator_irq_data.
+ * @die: Protection callback. If IC status reading or recovery actions
+ * fail fatal_cnt times this callback or BUG() is called. This
+ * callback should implement a final protection attempt like
+ * disabling the regulator. If protection succeeded this may
+ * return 0. If anything else is returned the core assumes final
+ * protection failed and calls BUG() as a last resort.
+ * @map_event: Driver callback to map IRQ status into regulator devices with
+ * events / errors. NOTE: callback MUST initialize both the
+ * errors and notifs for all rdevs which it signals having
+ * active events as core does not clean the map data.
+ * REGULATOR_FAILED_RETRY can be returned to indicate that the
+ * status reading from IC failed. If this is repeated for
+ * fatal_cnt times the core will call die() callback or BUG()
+ * as a last resort to protect the HW.
+ * @renable: Optional callback to check status (if HW supports that) before
+ * re-enabling IRQ. If implemented this should clear the error
+ * flags so that errors fetched by regulator_get_error_flags()
+ * are updated. If callback is not implemented then errors are
+ * assumed to be cleared and IRQ is re-enabled.
+ * REGULATOR_FAILED_RETRY can be returned to
+ * indicate that the status reading from IC failed. If this is
+ * repeated for 'fatal_cnt' times the core will call die()
+ * callback or BUG() as a last resort to protect the HW.
+ * Returning zero indicates that the problem in HW has been solved
+ * and IRQ will be re-enabled. Returning REGULATOR_ERROR_ON
+ * indicates the error condition is still active and keeps IRQ
+ * disabled. Please note that returning REGULATOR_ERROR_ON does
+ * not retrigger evaluating what events are active or resending
+ * notifications. If this is needed you probably want to return
+ * zero and allow IRQ to retrigger causing events to be
+ * re-evaluated and re-sent.
+ *
+ * This structure is used for registering regulator IRQ notification helper.
+ */
+struct regulator_irq_desc {
+ const char *name;
+ int irq_flags;
+ int fatal_cnt;
+ int reread_ms;
+ int irq_off_ms;
+ bool skip_off;
+ bool high_prio;
+ void *data;
+
+ int (*die)(struct regulator_irq_data *rid);
+ int (*map_event)(int irq, struct regulator_irq_data *rid,
+ unsigned long *dev_mask);
+ int (*renable)(struct regulator_irq_data *rid);
+};
+
+/*
+ * Return values for regulator IRQ helpers.
+ */
+enum {
+ REGULATOR_ERROR_CLEARED,
+ REGULATOR_FAILED_RETRY,
+ REGULATOR_ERROR_ON,
+};
+
/*
* struct coupling_desc
*
@@ -477,6 +599,9 @@ struct regulator_dev {
/* time when this regulator was disabled last time */
ktime_t last_off;
+ int cached_err;
+ bool use_cached_err;
+ spinlock_t err_lock;
};
struct regulator_dev *
@@ -491,6 +616,16 @@ void devm_regulator_unregister(struct device *dev, struct regulator_dev *rdev);
int regulator_notifier_call_chain(struct regulator_dev *rdev,
unsigned long event, void *data);
+void *devm_regulator_irq_helper(struct device *dev,
+ const struct regulator_irq_desc *d, int irq,
+ int irq_flags, int common_errs,
+ int *per_rdev_errs, struct regulator_dev **rdev,
+ int rdev_amount);
+void *regulator_irq_helper(struct device *dev,
+ const struct regulator_irq_desc *d, int irq,
+ int irq_flags, int common_errs, int *per_rdev_errs,
+ struct regulator_dev **rdev, int rdev_amount);
+void regulator_irq_helper_cancel(void **handle);
void *rdev_get_drvdata(struct regulator_dev *rdev);
struct device *rdev_get_dev(struct regulator_dev *rdev);