[PATCH 03/11] firmware: arm_scmi: introduce common protocol interface
Thara Gopinath
thara.gopinath at linaro.org
Mon Oct 26 09:07:12 EDT 2020
On 10/21/20 6:27 AM, Cristian Marussi wrote:
> On Tue, Oct 20, 2020 at 10:47:10PM -0400, Thara Gopinath wrote:
>>
>>
>> On 10/14/20 11:05 AM, Cristian Marussi wrote:
>>> Introduce generic get_ops/put_ops handle operations: any protocol, both
>>> standard or custom, now exposes its operations through this common
>>> interface which internally takes care to account for protocols' usage:
>>> protocols' initialization is now performed on demand as soon as the first
>>> user shows up while deinitialization (if any) is performed once
>>> the last user of a protocol has gone.
>>> Registered events' notifier are tracked too against the related protocol.
>>> Convert all SCMI drivers to the new interface too.
>>>
>>> Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
>>> ---
>>
>> [...]
>>
>>
>>> diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
>>> index bad1d0130e96..049220efd227 100644
>>> --- a/drivers/firmware/arm_scmi/driver.c
>>> +++ b/drivers/firmware/arm_scmi/driver.c
>>> @@ -585,7 +585,7 @@ void *scmi_get_proto_priv(const struct scmi_handle *handle, u8 protocol_id)
>>> * Return: A reference to an initialized protocol instance or error on failure.
>>> */
>>> static struct scmi_protocol_instance * __must_check
>>> -scmi_get_protocol_instance(struct scmi_handle *handle, u8 protocol_id)
>>> +scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id)
>>> {
>>> int ret = -ENOMEM;
>>> void *gid;
>>> @@ -655,7 +655,7 @@ scmi_get_protocol_instance(struct scmi_handle *handle, u8 protocol_id)
>>> *
>>> * Return: 0 if protocol was acquired successfully.
>>> */
>>> -int scmi_acquire_protocol(struct scmi_handle *handle, u8 protocol_id)
>>> +int scmi_acquire_protocol(const struct scmi_handle *handle, u8 protocol_id)
>>> {
>>> return IS_ERR(scmi_get_protocol_instance(handle, protocol_id));
>>> }
>>> @@ -668,7 +668,7 @@ int scmi_acquire_protocol(struct scmi_handle *handle, u8 protocol_id)
>>> * Remove one user for the specified protocol and triggers de-initialization
>>> * and resources de-allocation once the last user has gone.
>>> */
>>> -void scmi_release_protocol(struct scmi_handle *handle, u8 protocol_id)
>>> +void scmi_release_protocol(const struct scmi_handle *handle, u8 protocol_id)
>>> {
>>> struct scmi_info *info = handle_to_scmi_info(handle);
>>> struct scmi_protocol_instance *pi;
>>> @@ -700,6 +700,29 @@ void scmi_release_protocol(struct scmi_handle *handle, u8 protocol_id)
>>> mutex_unlock(&info->protocols_mtx);
>>> }
>>> +/**
>>> + * scmi_get_protocol_operations - Get protocol operations
>>> + * @handle: A reference to the SCMI platform instance.
>>> + * @protocol_id: The protocol being requested.
>>> + *
>>> + * Get hold of a protocol accounting for its usage, eventually triggering its
>>> + * initialization, and returning the protocol specific operations.
>>> + *
>>> + * Return: A reference to the requested protocol operations or error.
>>> + * Must be checked for errors by caller.
>>> + */
>>> +static const void __must_check
>>> +*scmi_get_protocol_operations(const struct scmi_handle *handle, u8 protocol_id)
>>> +{
>>> + struct scmi_protocol_instance *pi;
>>> +
>>> + pi = scmi_get_protocol_instance(handle, protocol_id);
>>> + if (IS_ERR(pi))
>>> + return pi;
>>> +
>>> + return pi->proto->ops;
>>> +} > +
>>> void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
>>> u8 *prot_imp)
>>> {
>>> @@ -975,6 +998,8 @@ static int scmi_probe(struct platform_device *pdev)
>>> handle = &info->handle;
>>> handle->dev = info->dev;
>>> handle->version = &info->version;
>>> + handle->get_ops = scmi_get_protocol_operations;
>>> + handle->put_ops = scmi_release_protocol;
>>
>>
>> Why do you need get_ops and put_ops? Why not have the drivers call
>> scmi_acquire_protocol and scmi_release_protocol directly and get the ops
>> from retrieved scmi_get_protocol_instance ? IMHO, this makes it more
>> readable. Also, this will make the usage of scmi_acquire_protocol and
>> scmi_release_protocol more consistent. Right now, notify.c uses
>> scmi_acquire_protocol to acquire protocol because there is no need for ops
>> and other drivers use get_ops to acquire protocol. Kind of confusing..
>>
>
> Trying to avoid exporting new synbols if not strictly needed, I exposed
> get_ops()/put_ops() via handle for the usage of the SCMI drivers users,
> while keeping scmi_acquire/release as internal non-exported wrappers used
> only by the SCMI core itself like notifications.
> You cannot call acquire/release from a loadable module as of now.
>
> Additionally I thougt to add these wrappers for cases in which like
> notifications you don't need the ops really (like notif or base) nor
> the related forced __must_check(like notif), but just to get hold of
> the protocol to avoid it being possibly unloaded.
>
> I would antyway keep the get_ops/put_ops and I could just drop
> acquire/release if confusing and use the raw ops methods also internally,
> properly checking for the result everytime: currently notifications core
> takes care to acquire a protocol only once the requested event has been
> registered by some protocol (i.e. event handler is NOT pending) so that
> I do not trigger a protocol initialization when registering a notifier
> against a still unknown event: as a consequence acquire/release when
> called in the notif context cannot fail, so I don;t check.
>
> I'll try to simplify this though.
I think a standard interface is better. So either a get_ops/put_ops or
acquire_release that can be called by all users/drivers of a protocol
will standardize it. I will wait for your next version.
>
> Regards
>
> Cristian
>
>> --
>> Warm Regards
>> Thara
>>
>>> ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
>>> if (ret)
>>> diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
>>> index eae58b2a92cc..02b00af9b08f 100644
>>> --- a/drivers/firmware/arm_scmi/notify.c
>>> +++ b/drivers/firmware/arm_scmi/notify.c
>>> @@ -367,7 +367,7 @@ static struct scmi_event_handler *
>>> scmi_get_active_handler(struct scmi_notify_instance *ni, u32 evt_key);
>>> static void scmi_put_active_handler(struct scmi_notify_instance *ni,
>>> struct scmi_event_handler *hndl);
>>> -static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
>>> +static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
>>> struct scmi_event_handler *hndl);
>>> /**
>>> @@ -899,9 +899,21 @@ static inline int scmi_bind_event_handler(struct scmi_notify_instance *ni,
>>> if (!r_evt)
>>> return -EINVAL;
>>> - /* Remove from pending and insert into registered */
>>> + /*
>>> + * Remove from pending and insert into registered while getting hold
>>> + * of protocol instance.
>>> + */
>>> hash_del(&hndl->hash);
>>> + /*
>>> + * Acquire protocols only for NON pending handlers, so as NOT to trigger
>>> + * protocol initialization when a notifier is registered against a still
>>> + * not registered protocol, since it would make little sense to force init
>>> + * protocols for which still no SCMI driver user exists: they wouldn't
>>> + * emit any event anyway till some SCMI driver starts using it.
>>> + */
>>> + scmi_acquire_protocol(ni->handle, KEY_XTRACT_PROTO_ID(hndl->key));
>>> hndl->r_evt = r_evt;
>>> +
>>> mutex_lock(&r_evt->proto->registered_mtx);
>>> hash_add(r_evt->proto->registered_events_handlers,
>>> &hndl->hash, hndl->key);
>>> @@ -1192,41 +1204,65 @@ static int scmi_disable_events(struct scmi_event_handler *hndl)
>>> * * unregister and free the handler itself
>>> *
>>> * Context: Assumes all the proper locking has been managed by the caller.
>>> + *
>>> + * Return: True if handler was freed (users dropped to zero)
>>> */
>>> -static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
>>> +static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
>>> struct scmi_event_handler *hndl)
>>> {
>>> + bool freed = false;
>>> +
>>> if (refcount_dec_and_test(&hndl->users)) {
>>> if (!IS_HNDL_PENDING(hndl))
>>> scmi_disable_events(hndl);
>>> scmi_free_event_handler(hndl);
>>> + freed = true;
>>> }
>>> +
>>> + return freed;
>>> }
>>> static void scmi_put_handler(struct scmi_notify_instance *ni,
>>> struct scmi_event_handler *hndl)
>>> {
>>> + bool freed;
>>> + u8 protocol_id;
>>> struct scmi_registered_event *r_evt = hndl->r_evt;
>>> mutex_lock(&ni->pending_mtx);
>>> - if (r_evt)
>>> + if (r_evt) {
>>> + protocol_id = r_evt->proto->id;
>>> mutex_lock(&r_evt->proto->registered_mtx);
>>> + }
>>> - scmi_put_handler_unlocked(ni, hndl);
>>> + freed = scmi_put_handler_unlocked(ni, hndl);
>>> - if (r_evt)
>>> + if (r_evt) {
>>> mutex_unlock(&r_evt->proto->registered_mtx);
>>> + /*
>>> + * Only registered handler acquired protocol; must be here
>>> + * released only AFTER unlocking registered_mtx, since
>>> + * releasing a protocol can trigger its de-initialization
>>> + * (ie. including r_evt and registered_mtx)
>>> + */
>>> + if (freed)
>>> + scmi_release_protocol(ni->handle, protocol_id);
>>> + }
>>> mutex_unlock(&ni->pending_mtx);
>>> }
>>> static void scmi_put_active_handler(struct scmi_notify_instance *ni,
>>> struct scmi_event_handler *hndl)
>>> {
>>> + bool freed;
>>> struct scmi_registered_event *r_evt = hndl->r_evt;
>>> + u8 protocol_id = r_evt->proto->id;
>>> mutex_lock(&r_evt->proto->registered_mtx);
>>> - scmi_put_handler_unlocked(ni, hndl);
>>> + freed = scmi_put_handler_unlocked(ni, hndl);
>>> mutex_unlock(&r_evt->proto->registered_mtx);
>>> + if (freed)
>>> + scmi_release_protocol(ni->handle, protocol_id);
>>> }
>>> /**
>>> diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
>>> index 13e215f359fb..bd9cb2583557 100644
>>> --- a/drivers/firmware/arm_scmi/perf.c
>>> +++ b/drivers/firmware/arm_scmi/perf.c
>>> @@ -857,7 +857,7 @@ static const struct scmi_event_ops perf_event_ops = {
>>> .fill_custom_report = scmi_perf_fill_custom_report,
>>> };
>>> -static int scmi_perf_protocol_init(struct scmi_handle *handle)
>>> +static int scmi_perf_protocol_init(const struct scmi_handle *handle)
>>> {
>>> int domain;
>>> u32 version;
>>> @@ -896,7 +896,6 @@ static int scmi_perf_protocol_init(struct scmi_handle *handle)
>>> pinfo->num_domains);
>>> pinfo->version = version;
>>> - handle->perf_ops = &perf_ops;
>>> return scmi_set_proto_priv(handle, SCMI_PROTOCOL_PERF, pinfo);
>>> }
>>> diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
>>> index e0b29ed4e09a..1e026b5530a7 100644
>>> --- a/drivers/firmware/arm_scmi/power.c
>>> +++ b/drivers/firmware/arm_scmi/power.c
>>> @@ -262,7 +262,7 @@ static const struct scmi_event_ops power_event_ops = {
>>> .fill_custom_report = scmi_power_fill_custom_report,
>>> };
>>> -static int scmi_power_protocol_init(struct scmi_handle *handle)
>>> +static int scmi_power_protocol_init(const struct scmi_handle *handle)
>>> {
>>> int domain;
>>> u32 version;
>>> @@ -297,7 +297,6 @@ static int scmi_power_protocol_init(struct scmi_handle *handle)
>>> pinfo->num_domains);
>>> pinfo->version = version;
>>> - handle->power_ops = &power_ops;
>>> return scmi_set_proto_priv(handle, SCMI_PROTOCOL_POWER, pinfo);
>>> }
>>> diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
>>> index f70e9b5108d5..b7da4de0e56e 100644
>>> --- a/drivers/firmware/arm_scmi/reset.c
>>> +++ b/drivers/firmware/arm_scmi/reset.c
>>> @@ -274,7 +274,7 @@ static const struct scmi_event_ops reset_event_ops = {
>>> .fill_custom_report = scmi_reset_fill_custom_report,
>>> };
>>> -static int scmi_reset_protocol_init(struct scmi_handle *handle)
>>> +static int scmi_reset_protocol_init(const struct scmi_handle *handle)
>>> {
>>> int domain;
>>> u32 version;
>>> @@ -309,7 +309,6 @@ static int scmi_reset_protocol_init(struct scmi_handle *handle)
>>> pinfo->num_domains);
>>> pinfo->version = version;
>>> - handle->reset_ops = &reset_ops;
>>> return scmi_set_proto_priv(handle, SCMI_PROTOCOL_RESET, pinfo);
>>> }
>>> diff --git a/drivers/firmware/arm_scmi/scmi_pm_domain.c b/drivers/firmware/arm_scmi/scmi_pm_domain.c
>>> index 9e44479f0284..bfea56f77890 100644
>>> --- a/drivers/firmware/arm_scmi/scmi_pm_domain.c
>>> +++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c
>>> @@ -2,7 +2,7 @@
>>> /*
>>> * SCMI Generic power domain support.
>>> *
>>> - * Copyright (C) 2018 ARM Ltd.
>>> + * Copyright (C) 2018-2020 ARM Ltd.
>>> */
>>> #include <linux/err.h>
>>> @@ -11,6 +11,8 @@
>>> #include <linux/pm_domain.h>
>>> #include <linux/scmi_protocol.h>
>>> +static const struct scmi_power_ops *power_ops;
>>> +
>>> struct scmi_pm_domain {
>>> struct generic_pm_domain genpd;
>>> const struct scmi_handle *handle;
>>> @@ -25,16 +27,15 @@ static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
>>> int ret;
>>> u32 state, ret_state;
>>> struct scmi_pm_domain *pd = to_scmi_pd(domain);
>>> - const struct scmi_power_ops *ops = pd->handle->power_ops;
>>> if (power_on)
>>> state = SCMI_POWER_STATE_GENERIC_ON;
>>> else
>>> state = SCMI_POWER_STATE_GENERIC_OFF;
>>> - ret = ops->state_set(pd->handle, pd->domain, state);
>>> + ret = power_ops->state_set(pd->handle, pd->domain, state);
>>> if (!ret)
>>> - ret = ops->state_get(pd->handle, pd->domain, &ret_state);
>>> + ret = power_ops->state_get(pd->handle, pd->domain, &ret_state);
>>> if (!ret && state != ret_state)
>>> return -EIO;
>>> @@ -61,10 +62,14 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
>>> struct generic_pm_domain **domains;
>>> const struct scmi_handle *handle = sdev->handle;
>>> - if (!handle || !handle->power_ops)
>>> + if (!handle)
>>> return -ENODEV;
>>> - num_domains = handle->power_ops->num_domains_get(handle);
>>> + power_ops = handle->get_ops(handle, SCMI_PROTOCOL_POWER);
>>> + if (IS_ERR(power_ops))
>>> + return PTR_ERR(power_ops);
>>> +
>>> + num_domains = power_ops->num_domains_get(handle);
>>> if (num_domains < 0) {
>>> dev_err(dev, "number of domains not found\n");
>>> return num_domains;
>>> @@ -85,14 +90,14 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
>>> for (i = 0; i < num_domains; i++, scmi_pd++) {
>>> u32 state;
>>> - if (handle->power_ops->state_get(handle, i, &state)) {
>>> + if (power_ops->state_get(handle, i, &state)) {
>>> dev_warn(dev, "failed to get state for domain %d\n", i);
>>> continue;
>>> }
>>> scmi_pd->domain = i;
>>> scmi_pd->handle = handle;
>>> - scmi_pd->name = handle->power_ops->name_get(handle, i);
>>> + scmi_pd->name = power_ops->name_get(handle, i);
>>> scmi_pd->genpd.name = scmi_pd->name;
>>> scmi_pd->genpd.power_off = scmi_pd_power_off;
>>> scmi_pd->genpd.power_on = scmi_pd_power_on;
>>> @@ -111,6 +116,13 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
>>> return 0;
>>> }
>>> +static void scmi_pm_domain_remove(struct scmi_device *sdev)
>>> +{
>>> + const struct scmi_handle *handle = sdev->handle;
>>> +
>>> + handle->put_ops(handle, SCMI_PROTOCOL_POWER);
>>> +}
>>> +
>>> static const struct scmi_device_id scmi_id_table[] = {
>>> { SCMI_PROTOCOL_POWER, "genpd" },
>>> { },
>>> @@ -120,6 +132,7 @@ MODULE_DEVICE_TABLE(scmi, scmi_id_table);
>>> static struct scmi_driver scmi_power_domain_driver = {
>>> .name = "scmi-power-domain",
>>> .probe = scmi_pm_domain_probe,
>>> + .remove = scmi_pm_domain_remove,
>>> .id_table = scmi_id_table,
>>> };
>>> module_scmi_driver(scmi_power_domain_driver);
>>> diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
>>> index 8a0a599558ba..e0129dcd322f 100644
>>> --- a/drivers/firmware/arm_scmi/sensors.c
>>> +++ b/drivers/firmware/arm_scmi/sensors.c
>>> @@ -334,7 +334,7 @@ static const struct scmi_event_ops sensor_event_ops = {
>>> .fill_custom_report = scmi_sensor_fill_custom_report,
>>> };
>>> -static int scmi_sensors_protocol_init(struct scmi_handle *handle)
>>> +static int scmi_sensors_protocol_init(const struct scmi_handle *handle)
>>> {
>>> u32 version;
>>> struct sensors_info *sinfo;
>>> @@ -364,7 +364,6 @@ static int scmi_sensors_protocol_init(struct scmi_handle *handle)
>>> sinfo->num_sensors);
>>> sinfo->version = version;
>>> - handle->sensor_ops = &sensor_ops;
>>> return scmi_set_proto_priv(handle, SCMI_PROTOCOL_SENSOR, sinfo);
>>> }
>>> diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
>>> index 8f53f93c63ca..30e3510c1f07 100644
>>> --- a/drivers/firmware/arm_scmi/system.c
>>> +++ b/drivers/firmware/arm_scmi/system.c
>>> @@ -101,7 +101,7 @@ static const struct scmi_event_ops system_event_ops = {
>>> .fill_custom_report = scmi_system_fill_custom_report,
>>> };
>>> -static int scmi_system_protocol_init(struct scmi_handle *handle)
>>> +static int scmi_system_protocol_init(const struct scmi_handle *handle)
>>> {
>>> u32 version;
>>> struct scmi_system_info *pinfo;
>>> diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
>>> index d421e691318b..27ef71996a15 100644
>>> --- a/drivers/hwmon/scmi-hwmon.c
>>> +++ b/drivers/hwmon/scmi-hwmon.c
>>> @@ -2,7 +2,7 @@
>>> /*
>>> * System Control and Management Interface(SCMI) based hwmon sensor driver
>>> *
>>> - * Copyright (C) 2018 ARM Ltd.
>>> + * Copyright (C) 2018-2020 ARM Ltd.
>>> * Sudeep Holla <sudeep.holla at arm.com>
>>> */
>>> @@ -13,6 +13,8 @@
>>> #include <linux/sysfs.h>
>>> #include <linux/thermal.h>
>>> +static const struct scmi_sensor_ops *sensor_ops;
>>> +
>>> struct scmi_sensors {
>>> const struct scmi_handle *handle;
>>> const struct scmi_sensor_info **info[hwmon_max];
>>> @@ -72,7 +74,7 @@ static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
>>> const struct scmi_handle *h = scmi_sensors->handle;
>>> sensor = *(scmi_sensors->info[type] + channel);
>>> - ret = h->sensor_ops->reading_get(h, sensor->id, &value);
>>> + ret = sensor_ops->reading_get(h, sensor->id, &value);
>>> if (ret)
>>> return ret;
>>> @@ -170,10 +172,14 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>>> const struct hwmon_channel_info **ptr_scmi_ci;
>>> const struct scmi_handle *handle = sdev->handle;
>>> - if (!handle || !handle->sensor_ops)
>>> + if (!handle)
>>> return -ENODEV;
>>> - nr_sensors = handle->sensor_ops->count_get(handle);
>>> + sensor_ops = handle->get_ops(handle, SCMI_PROTOCOL_SENSOR);
>>> + if (IS_ERR(sensor_ops))
>>> + return PTR_ERR(sensor_ops);
>>> +
>>> + nr_sensors = sensor_ops->count_get(handle);
>>> if (!nr_sensors)
>>> return -EIO;
>>> @@ -184,7 +190,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>>> scmi_sensors->handle = handle;
>>> for (i = 0; i < nr_sensors; i++) {
>>> - sensor = handle->sensor_ops->info_get(handle, i);
>>> + sensor = sensor_ops->info_get(handle, i);
>>> if (!sensor)
>>> return -EINVAL;
>>> @@ -234,7 +240,7 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>>> }
>>> for (i = nr_sensors - 1; i >= 0 ; i--) {
>>> - sensor = handle->sensor_ops->info_get(handle, i);
>>> + sensor = sensor_ops->info_get(handle, i);
>>> if (!sensor)
>>> continue;
>>> @@ -258,6 +264,13 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
>>> return PTR_ERR_OR_ZERO(hwdev);
>>> }
>>> +static void scmi_hwmon_remove(struct scmi_device *sdev)
>>> +{
>>> + const struct scmi_handle *handle = sdev->handle;
>>> +
>>> + handle->put_ops(handle, SCMI_PROTOCOL_SENSOR);
>>> +}
>>> +
>>> static const struct scmi_device_id scmi_id_table[] = {
>>> { SCMI_PROTOCOL_SENSOR, "hwmon" },
>>> { },
>>> @@ -267,6 +280,7 @@ MODULE_DEVICE_TABLE(scmi, scmi_id_table);
>>> static struct scmi_driver scmi_hwmon_drv = {
>>> .name = "scmi-hwmon",
>>> .probe = scmi_hwmon_probe,
>>> + .remove = scmi_hwmon_remove,
>>> .id_table = scmi_id_table,
>>> };
>>> module_scmi_driver(scmi_hwmon_drv);
>>> diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c
>>> index 8d3a858e3b19..e48220dedb35 100644
>>> --- a/drivers/reset/reset-scmi.c
>>> +++ b/drivers/reset/reset-scmi.c
>>> @@ -2,7 +2,7 @@
>>> /*
>>> * ARM System Control and Management Interface (ARM SCMI) reset driver
>>> *
>>> - * Copyright (C) 2019 ARM Ltd.
>>> + * Copyright (C) 2019-2020 ARM Ltd.
>>> */
>>> #include <linux/module.h>
>>> @@ -11,6 +11,8 @@
>>> #include <linux/reset-controller.h>
>>> #include <linux/scmi_protocol.h>
>>> +static const struct scmi_reset_ops *reset_ops;
>>> +
>>> /**
>>> * struct scmi_reset_data - reset controller information structure
>>> * @rcdev: reset controller entity
>>> @@ -39,7 +41,7 @@ scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
>>> {
>>> const struct scmi_handle *handle = to_scmi_handle(rcdev);
>>> - return handle->reset_ops->assert(handle, id);
>>> + return reset_ops->assert(handle, id);
>>> }
>>> /**
>>> @@ -57,7 +59,7 @@ scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
>>> {
>>> const struct scmi_handle *handle = to_scmi_handle(rcdev);
>>> - return handle->reset_ops->deassert(handle, id);
>>> + return reset_ops->deassert(handle, id);
>>> }
>>> /**
>>> @@ -75,7 +77,7 @@ scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
>>> {
>>> const struct scmi_handle *handle = to_scmi_handle(rcdev);
>>> - return handle->reset_ops->reset(handle, id);
>>> + return reset_ops->reset(handle, id);
>>> }
>>> static const struct reset_control_ops scmi_reset_ops = {
>>> @@ -91,9 +93,13 @@ static int scmi_reset_probe(struct scmi_device *sdev)
>>> struct device_node *np = dev->of_node;
>>> const struct scmi_handle *handle = sdev->handle;
>>> - if (!handle || !handle->reset_ops)
>>> + if (!handle)
>>> return -ENODEV;
>>> + reset_ops = handle->get_ops(handle, SCMI_PROTOCOL_RESET);
>>> + if (IS_ERR(reset_ops))
>>> + return PTR_ERR(reset_ops);
>>> +
>>> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>> if (!data)
>>> return -ENOMEM;
>>> @@ -101,12 +107,19 @@ static int scmi_reset_probe(struct scmi_device *sdev)
>>> data->rcdev.ops = &scmi_reset_ops;
>>> data->rcdev.owner = THIS_MODULE;
>>> data->rcdev.of_node = np;
>>> - data->rcdev.nr_resets = handle->reset_ops->num_domains_get(handle);
>>> + data->rcdev.nr_resets = reset_ops->num_domains_get(handle);
>>> data->handle = handle;
>>> return devm_reset_controller_register(dev, &data->rcdev);
>>> }
>>> +static void scmi_reset_remove(struct scmi_device *sdev)
>>> +{
>>> + const struct scmi_handle *handle = sdev->handle;
>>> +
>>> + handle->put_ops(handle, SCMI_PROTOCOL_RESET);
>>> +}
>>> +
>>> static const struct scmi_device_id scmi_id_table[] = {
>>> { SCMI_PROTOCOL_RESET, "reset" },
>>> { },
>>> @@ -116,6 +129,7 @@ MODULE_DEVICE_TABLE(scmi, scmi_id_table);
>>> static struct scmi_driver scmi_reset_driver = {
>>> .name = "scmi-reset",
>>> .probe = scmi_reset_probe,
>>> + .remove = scmi_reset_remove,
>>> .id_table = scmi_id_table,
>>> };
>>> module_scmi_driver(scmi_reset_driver);
>>> diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
>>> index bc4f06d46bfb..bfe7017cff19 100644
>>> --- a/include/linux/scmi_protocol.h
>>> +++ b/include/linux/scmi_protocol.h
>>> @@ -257,11 +257,6 @@ struct scmi_notify_ops {
>>> *
>>> * @dev: pointer to the SCMI device
>>> * @version: pointer to the structure containing SCMI version information
>>> - * @power_ops: pointer to set of power protocol operations
>>> - * @perf_ops: pointer to set of performance protocol operations
>>> - * @clk_ops: pointer to set of clock protocol operations
>>> - * @sensor_ops: pointer to set of sensor protocol operations
>>> - * @reset_ops: pointer to set of reset protocol operations
>>> * @notify_ops: pointer to set of notifications related operations
>>> * @notify_priv: pointer to private data structure specific to notifications
>>> * (for internal use only)
>>> @@ -269,11 +264,11 @@ struct scmi_notify_ops {
>>> struct scmi_handle {
>>> struct device *dev;
>>> struct scmi_revision_info *version;
>>> - const struct scmi_perf_ops *perf_ops;
>>> - const struct scmi_clk_ops *clk_ops;
>>> - const struct scmi_power_ops *power_ops;
>>> - const struct scmi_sensor_ops *sensor_ops;
>>> - const struct scmi_reset_ops *reset_ops;
>>> +
>>> + const void __must_check *(*get_ops)(const struct scmi_handle *handle,
>>> + u8 proto);
>>> + void (*put_ops)(const struct scmi_handle *handle, u8 proto);
>>> +
>>> const struct scmi_notify_ops *notify_ops;
>>> void *notify_priv;
>>> };
>>>
>>
>>
--
Warm Regards
Thara
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