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Message-ID: <CAHp75VcHeiQgvZ5e+Dz+gpKghCo5RSTQLsyHGGSgdVQbVu2t+g@mail.gmail.com>
Date: Wed, 7 Apr 2021 16:21:45 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Cc: Matti Vaittinen <mazziesaccount@...il.com>,
Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>,
Rob Herring <robh+dt@...nel.org>,
Andy Gross <agross@...nel.org>,
Bjorn Andersson <bjorn.andersson@...aro.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
devicetree <devicetree@...r.kernel.org>,
linux-power <linux-power@...rohmeurope.com>,
linux-arm-msm@...r.kernel.org,
Linux-Renesas <linux-renesas-soc@...r.kernel.org>
Subject: Re: [PATCH v6 3/8] regulator: IRQ based event/error notification helpers
On Wed, Apr 7, 2021 at 1:04 PM Matti Vaittinen
<matti.vaittinen@...rohmeurope.com> wrote:
>
> Provide helper function for IC's implementing regulator notifications
> when an IRQ fires. The helper also works for IRQs which can not be acked.
> Helper can be set to disable the IRQ at handler and then re-enabling it
> on delayed work later. The helper also adds regulator_get_error_flags()
> errors in cache for the duration of IRQ disabling.
Thanks for an update, my comments below. After addressing them, feel free to add
Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
>
> ---
> v6 (fix issues noted by Andy):
> - remove unnecessary variable
> - use BIT(foo) instead of 1 << foo
> - use devm_add_action_or_reset()
> - do not check the irq parameter validity, leave that to
> request_threaded_irq()
> - put resource-managed function in devres.c
> - fix the kerneldocs for the new IRQ helpers
> v5:
> - fix the pr_emerg print
> v4:
> - Comment block styling
> - Added prints to point the potential HW failure before BUG()
> - Corrected typo from kerneldoc
> - added missing newlines
> ---
> drivers/regulator/Makefile | 2 +-
> drivers/regulator/core.c | 24 +-
> drivers/regulator/devres.c | 49 ++++
> drivers/regulator/irq_helpers.c | 396 +++++++++++++++++++++++++++++++
> include/linux/regulator/driver.h | 135 +++++++++++
> 5 files changed, 602 insertions(+), 4 deletions(-)
> create mode 100644 drivers/regulator/irq_helpers.c
>
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index 44d2f8bf4b74..e25f1c2d6c9b 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -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
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 16114aea099a..fabc83288e1b 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -4388,20 +4388,37 @@ 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;
Not critical, but I would rather have it this way
if (! bla bla bla) // space after ! on visibility purpose
return 0;
spin lock
ret =
spin unlock
return ret;
And drop ret = 0, the main reason why I pointed to this. We have a lot
of issues of hiding (potential) errors due to global assignments like
this. I saw some problematic patches that people unthoughtfully put
such an assignment to shut the compiler up about uninitialized
variables.
however it's not critical per se, can be refactored later.
> +}
> +
> static int _regulator_get_error_flags(struct regulator_dev *rdev,
> unsigned int *flags)
> {
> - int ret;
> + int ret, tmpret;
>
> regulator_lock(rdev);
>
> + ret = rdev_get_cached_err_flags(rdev);
> +
> /* sanity check */
> - if (!rdev->desc->ops->get_error_flags) {
> + if (rdev->desc->ops->get_error_flags) {
> + tmpret = rdev->desc->ops->get_error_flags(rdev, flags);
> + if (tmpret > 0)
> + ret |= tmpret;
Oh, I don't like this. Easy fix is to rename ret (okay, it's been used
elsewhere, so adding then) to something meaningful, like error_flags,
then you can easily understand that value should be positive and error
codes are negative.
> + } else if (!rdev->use_cached_err) {
> ret = -EINVAL;
> goto out;
> }
>
> - ret = rdev->desc->ops->get_error_flags(rdev, flags);
> out:
> regulator_unlock(rdev);
> return ret;
> @@ -5236,6 +5253,7 @@ 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
> diff --git a/drivers/regulator/devres.c b/drivers/regulator/devres.c
> index 3091210889e3..127262dcd3f7 100644
> --- a/drivers/regulator/devres.c
> +++ b/drivers/regulator/devres.c
> @@ -481,3 +481,52 @@ 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's with the default IRQF_ONESHOT
OR'ed
> + * 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 regulators associated with this IRQ.
> + * @rdev_amount: Amount of regulators associated wit this IRQ.
wit -> with
Can you describe, please, the return value meaning. It will be good
also to move detailed descriptions (expectations?) of the fields to
the Description section, here.
> + */
> +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)
I didn't get why you need the ** pointer instead of plain pointer.
> +{
> + 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);
> diff --git a/drivers/regulator/irq_helpers.c b/drivers/regulator/irq_helpers.c
> new file mode 100644
> index 000000000000..374ff0f3c6d3
> --- /dev/null
> +++ b/drivers/regulator/irq_helpers.c
> @@ -0,0 +1,396 @@
> +// 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@...rohmeurope.com>
> +
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/of_irq.h>
Not sure how this header is used. I haven't found any direct users of
it. Perhaps you wanted interrupt.h?
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
+ Blank line? I would separate group of generic headers with
particular to the subsystem
> +#include <linux/regulator/driver.h>
> +
> +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 die_loudly(const char *msg)
I feel that this is a too generic name, perhaps rdev_die_loudly().
> +{
> + pr_emerg("%s\n", msg);
> + BUG();
> +}
> +
> +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)
> + ret = d->die(rid);
> + else
> + die_loudly("Regulator HW failure? - no IC recovery");
> +
> + /*
> + * If the 'last resort' IC recovery failed we will have
> + * nothing else left to do...
> + */
> + if (ret)
> + die_loudly("Regulator HW failure? - IC recovery failed");
Looking at the above code this will be executed if and only if
d->die() is defined, correct?
In that case, why not
if (d->die) {
ret = ...
if (ret)
rdev_die_loudly(...);
} else
rdev_die_loudly(...);
?
> + /*
> + * 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 new nice loop. In any case we should clear error flags
have a new
> + * 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 few cycles by not clearing statuses prior this call.
We spare a few
prior to this
> + * 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 given safety limit we call IC specific die
exceeds the given
> + * 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
> + * ourself in the head and leave problematic regulator enabled. So
ourselves
the problematic regulator
> + * 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 was no status bits for us. We'd
were
> + * better leave spurious IRQ handling to genirq
> + */
> + if (ret || !rdev_map)
> + return IRQ_NONE;
> +
> + /*
> + * Some events are bogus if regulator is disabled. Skip such events
if the regulator
> + * 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) {
> + struct regulator_err_state *stat;
> + int len;
Redundant, see below.
> + struct regulator_dev *rdev;
> +
> + stat = &rid->states[i];
> + len = sizeof(stat->notifs);
> +
> + rdev = stat->rdev;
> + for_each_set_bit(j, &stat->notifs, 8 * len)
BITS_PER_TYPE(stat->notifs)
> + regulator_notifier_call_chain(rdev, BIT(j - 1), 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 (d->die)
> + ret = d->die(rid);
> +
> + /*
> + * If die() failed or was not implemented just BUG() as last
> + * attemt to save HW.
> + */
> + if (ret)
> + die_loudly("Regulator HW failure? - retry count exceeded");
> + }
> +
> + 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)
> + /* Can we trust writing this boolean is atomic? */
No. boolean is a compiler / platform specific and it may potentially
be written in a non-atomic way.
> + 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's with the default IRQF_ONESHOT
OR'ed
> + * 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 regulators associated with this IRQ.
> + * @rdev_amount: Amount of regulators associated wit this IRQ.
> + */
> +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);
> diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
> index d7c77ee370f3..03a8eee9fca9 100644
> --- a/include/linux/regulator/driver.h
> +++ b/include/linux/regulator/driver.h
> @@ -409,6 +409,128 @@ 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 regulator.
on the regulator
> + * @errors: Errors which are active on 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 to see if new problems have been
re-enable / reenable
> + * 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 for reporting regulator
Ditto.
> + * 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 repeteadly failing. If fatal_cnt is given the IRQ
repeatedly
> + * 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 final protection attempt like
implement a final
> + * 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 impelemted then errors are
implemented
> + * 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
> *
> @@ -473,6 +595,9 @@ struct regulator_dev {
>
> /* time when this regulator was disabled last time */
> unsigned long last_off_jiffy;
> + int cached_err;
> + bool use_cached_err;
> + spinlock_t err_lock;
> };
>
> struct regulator_dev *
> @@ -487,6 +612,16 @@ 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);
> --
> 2.25.4
>
>
> --
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
>
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> Simon says - in Latin please.
> ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
> Thanks to Simon Glass for the translation =]
--
With Best Regards,
Andy Shevchenko
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