// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Generic Framer framework.
*
* Copyright 2023 CS GROUP France
*
* Author: Herve Codina <[email protected]>
*/
#include <linux/device.h>
#include <linux/framer/framer.h>
#include <linux/framer/framer-provider.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
static void framer_release(struct device *dev);
static const struct class framer_class = {
.name = "framer",
.dev_release = framer_release,
};
static DEFINE_MUTEX(framer_provider_mutex);
static LIST_HEAD(framer_provider_list);
static DEFINE_IDA(framer_ida);
#define dev_to_framer(a) (container_of((a), struct framer, dev))
int framer_pm_runtime_get(struct framer *framer)
{
int ret;
if (!pm_runtime_enabled(&framer->dev))
return -EOPNOTSUPP;
ret = pm_runtime_get(&framer->dev);
if (ret < 0 && ret != -EINPROGRESS)
pm_runtime_put_noidle(&framer->dev);
return ret;
}
EXPORT_SYMBOL_GPL(framer_pm_runtime_get);
int framer_pm_runtime_get_sync(struct framer *framer)
{
int ret;
if (!pm_runtime_enabled(&framer->dev))
return -EOPNOTSUPP;
ret = pm_runtime_get_sync(&framer->dev);
if (ret < 0)
pm_runtime_put_sync(&framer->dev);
return ret;
}
EXPORT_SYMBOL_GPL(framer_pm_runtime_get_sync);
int framer_pm_runtime_put(struct framer *framer)
{
if (!pm_runtime_enabled(&framer->dev))
return -EOPNOTSUPP;
return pm_runtime_put(&framer->dev);
}
EXPORT_SYMBOL_GPL(framer_pm_runtime_put);
int framer_pm_runtime_put_sync(struct framer *framer)
{
if (!pm_runtime_enabled(&framer->dev))
return -EOPNOTSUPP;
return pm_runtime_put_sync(&framer->dev);
}
EXPORT_SYMBOL_GPL(framer_pm_runtime_put_sync);
/**
* framer_init - framer internal initialization before framer operation
* @framer: the framer returned by framer_get()
*
* Used to allow framer's driver to perform framer internal initialization,
* such as PLL block powering, clock initialization or anything that's
* is required by the framer to perform the start of operation.
* Must be called before framer_power_on().
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_init(struct framer *framer)
{
bool start_polling = false;
int ret;
ret = framer_pm_runtime_get_sync(framer);
if (ret < 0 && ret != -EOPNOTSUPP)
return ret;
ret = 0; /* Override possible ret == -EOPNOTSUPP */
mutex_lock(&framer->mutex);
if (framer->power_count > framer->init_count)
dev_warn(&framer->dev, "framer_power_on was called before framer init\n");
if (framer->init_count == 0) {
if (framer->ops->init) {
ret = framer->ops->init(framer);
if (ret < 0) {
dev_err(&framer->dev, "framer init failed --> %d\n", ret);
goto out;
}
}
if (framer->ops->flags & FRAMER_FLAG_POLL_STATUS)
start_polling = true;
}
++framer->init_count;
out:
mutex_unlock(&framer->mutex);
if (!ret && start_polling) {
ret = framer_get_status(framer, &framer->prev_status);
if (ret < 0) {
dev_warn(&framer->dev, "framer get status failed --> %d\n", ret);
/* Will be retried on polling_work */
ret = 0;
}
queue_delayed_work(system_power_efficient_wq, &framer->polling_work, 1 * HZ);
}
framer_pm_runtime_put(framer);
return ret;
}
EXPORT_SYMBOL_GPL(framer_init);
/**
* framer_exit - Framer internal un-initialization
* @framer: the framer returned by framer_get()
*
* Must be called after framer_power_off().
*/
int framer_exit(struct framer *framer)
{
int ret;
ret = framer_pm_runtime_get_sync(framer);
if (ret < 0 && ret != -EOPNOTSUPP)
return ret;
ret = 0; /* Override possible ret == -EOPNOTSUPP */
mutex_lock(&framer->mutex);
--framer->init_count;
if (framer->init_count == 0) {
if (framer->ops->flags & FRAMER_FLAG_POLL_STATUS) {
mutex_unlock(&framer->mutex);
cancel_delayed_work_sync(&framer->polling_work);
mutex_lock(&framer->mutex);
}
if (framer->ops->exit)
framer->ops->exit(framer);
}
mutex_unlock(&framer->mutex);
framer_pm_runtime_put(framer);
return ret;
}
EXPORT_SYMBOL_GPL(framer_exit);
/**
* framer_power_on - Enable the framer and enter proper operation
* @framer: the framer returned by framer_get()
*
* Must be called after framer_init().
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_power_on(struct framer *framer)
{
int ret;
if (framer->pwr) {
ret = regulator_enable(framer->pwr);
if (ret)
return ret;
}
ret = framer_pm_runtime_get_sync(framer);
if (ret < 0 && ret != -EOPNOTSUPP)
goto err_pm_sync;
mutex_lock(&framer->mutex);
if (framer->power_count == 0 && framer->ops->power_on) {
ret = framer->ops->power_on(framer);
if (ret < 0) {
dev_err(&framer->dev, "framer poweron failed --> %d\n", ret);
goto err_pwr_on;
}
}
++framer->power_count;
mutex_unlock(&framer->mutex);
return 0;
err_pwr_on:
mutex_unlock(&framer->mutex);
framer_pm_runtime_put_sync(framer);
err_pm_sync:
if (framer->pwr)
regulator_disable(framer->pwr);
return ret;
}
EXPORT_SYMBOL_GPL(framer_power_on);
/**
* framer_power_off - Disable the framer.
* @framer: the framer returned by framer_get()
*
* Must be called before framer_exit().
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_power_off(struct framer *framer)
{
int ret;
mutex_lock(&framer->mutex);
if (framer->power_count == 1 && framer->ops->power_off) {
ret = framer->ops->power_off(framer);
if (ret < 0) {
dev_err(&framer->dev, "framer poweroff failed --> %d\n", ret);
mutex_unlock(&framer->mutex);
return ret;
}
}
--framer->power_count;
mutex_unlock(&framer->mutex);
framer_pm_runtime_put(framer);
if (framer->pwr)
regulator_disable(framer->pwr);
return 0;
}
EXPORT_SYMBOL_GPL(framer_power_off);
/**
* framer_get_status() - Gets the framer status
* @framer: the framer returned by framer_get()
* @status: the status to retrieve
*
* Used to get the framer status. framer_init() must have been called
* on the framer.
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_get_status(struct framer *framer, struct framer_status *status)
{
int ret;
if (!framer->ops->get_status)
return -EOPNOTSUPP;
/* Be sure to have known values (struct padding and future extensions) */
memset(status, 0, sizeof(*status));
mutex_lock(&framer->mutex);
ret = framer->ops->get_status(framer, status);
mutex_unlock(&framer->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(framer_get_status);
/**
* framer_set_config() - Sets the framer configuration
* @framer: the framer returned by framer_get()
* @config: the configuration to set
*
* Used to set the framer configuration. framer_init() must have been called
* on the framer.
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_set_config(struct framer *framer, const struct framer_config *config)
{
int ret;
if (!framer->ops->set_config)
return -EOPNOTSUPP;
mutex_lock(&framer->mutex);
ret = framer->ops->set_config(framer, config);
mutex_unlock(&framer->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(framer_set_config);
/**
* framer_get_config() - Gets the framer configuration
* @framer: the framer returned by framer_get()
* @config: the configuration to retrieve
*
* Used to get the framer configuration. framer_init() must have been called
* on the framer.
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_get_config(struct framer *framer, struct framer_config *config)
{
int ret;
if (!framer->ops->get_config)
return -EOPNOTSUPP;
mutex_lock(&framer->mutex);
ret = framer->ops->get_config(framer, config);
mutex_unlock(&framer->mutex);
return ret;
}
EXPORT_SYMBOL_GPL(framer_get_config);
static void framer_polling_work(struct work_struct *work)
{
struct framer *framer = container_of(work, struct framer, polling_work.work);
struct framer_status status;
int ret;
ret = framer_get_status(framer, &status);
if (ret) {
dev_err(&framer->dev, "polling, get status failed (%d)\n", ret);
goto end;
}
if (memcmp(&framer->prev_status, &status, sizeof(status))) {
blocking_notifier_call_chain(&framer->notifier_list,
FRAMER_EVENT_STATUS, NULL);
memcpy(&framer->prev_status, &status, sizeof(status));
}
end:
/* Re-schedule task in 1 sec */
queue_delayed_work(system_power_efficient_wq, &framer->polling_work, 1 * HZ);
}
/**
* framer_notifier_register() - Registers a notifier
* @framer: the framer returned by framer_get()
* @nb: the notifier block to register
*
* Used to register a notifier block on framer events. framer_init() must have
* been called on the framer.
* The available framer events are present in enum framer_events.
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_notifier_register(struct framer *framer, struct notifier_block *nb)
{
return blocking_notifier_chain_register(&framer->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(framer_notifier_register);
/**
* framer_notifier_unregister() - Unregisters a notifier
* @framer: the framer returned by framer_get()
* @nb: the notifier block to unregister
*
* Used to unregister a notifier block. framer_init() must have
* been called on the framer.
*
* Return: %0 if successful, a negative error code otherwise
*/
int framer_notifier_unregister(struct framer *framer, struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&framer->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(framer_notifier_unregister);
static struct framer_provider *framer_provider_of_lookup(const struct device_node *node)
{
struct framer_provider *framer_provider;
list_for_each_entry(framer_provider, &framer_provider_list, list) {
if (device_match_of_node(framer_provider->dev, node))
return framer_provider;
}
return ERR_PTR(-EPROBE_DEFER);
}
static struct framer *framer_of_get_from_provider(const struct of_phandle_args *args)
{
struct framer_provider *framer_provider;
struct framer *framer;
mutex_lock(&framer_provider_mutex);
framer_provider = framer_provider_of_lookup(args->np);
if (IS_ERR(framer_provider) || !try_module_get(framer_provider->owner)) {
framer = ERR_PTR(-EPROBE_DEFER);
goto end;
}
framer = framer_provider->of_xlate(framer_provider->dev, args);
module_put(framer_provider->owner);
end:
mutex_unlock(&framer_provider_mutex);
return framer;
}
static struct framer *framer_of_get_byphandle(struct device_node *np, const char *propname,
int index)
{
struct of_phandle_args args;
struct framer *framer;
int ret;
ret = of_parse_phandle_with_optional_args(np, propname, "#framer-cells", index, &args);
if (ret)
return ERR_PTR(-ENODEV);
if (!of_device_is_available(args.np)) {
framer = ERR_PTR(-ENODEV);
goto out_node_put;
}
framer = framer_of_get_from_provider(&args);
out_node_put:
of_node_put(args.np);
return framer;
}
static struct framer *framer_of_get_byparent(struct device_node *np, int index)
{
struct of_phandle_args args;
struct framer *framer;
args.np = of_get_parent(np);
args.args_count = 1;
args.args[0] = index;
while (args.np) {
framer = framer_of_get_from_provider(&args);
if (IS_ERR(framer) && PTR_ERR(framer) != -EPROBE_DEFER) {
args.np = of_get_next_parent(args.np);
continue;
}
of_node_put(args.np);
return framer;
}
return ERR_PTR(-ENODEV);
}
/**
* framer_get() - lookup and obtain a reference to a framer.
* @dev: device that requests the framer
* @con_id: name of the framer from device's point of view
*
* Returns the framer driver, after getting a refcount to it; or
* -ENODEV if there is no such framer. The caller is responsible for
* calling framer_put() to release that count.
*/
struct framer *framer_get(struct device *dev, const char *con_id)
{
struct framer *framer = ERR_PTR(-ENODEV);
struct device_link *link;
int ret;
if (dev->of_node) {
if (con_id)
framer = framer_of_get_byphandle(dev->of_node, con_id, 0);
else
framer = framer_of_get_byparent(dev->of_node, 0);
}
if (IS_ERR(framer))
return framer;
get_device(&framer->dev);
if (!try_module_get(framer->ops->owner)) {
ret = -EPROBE_DEFER;
goto err_put_device;
}
link = device_link_add(dev, &framer->dev, DL_FLAG_STATELESS);
if (!link) {
dev_err(dev, "failed to create device_link to %s\n", dev_name(&framer->dev));
ret = -EPROBE_DEFER;
goto err_module_put;
}
return framer;
err_module_put:
module_put(framer->ops->owner);
err_put_device:
put_device(&framer->dev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(framer_get);
/**
* framer_put() - release the framer
* @dev: device that wants to release this framer
* @framer: the framer returned by framer_get()
*
* Releases a refcount the caller received from framer_get().
*/
void framer_put(struct device *dev, struct framer *framer)
{
device_link_remove(dev, &framer->dev);
module_put(framer->ops->owner);
put_device(&framer->dev);
}
EXPORT_SYMBOL_GPL(framer_put);
static void devm_framer_put(struct device *dev, void *res)
{
struct framer *framer = *(struct framer **)res;
framer_put(dev, framer);
}
/**
* devm_framer_get() - lookup and obtain a reference to a framer.
* @dev: device that requests this framer
* @con_id: name of the framer from device's point of view
*
* Gets the framer using framer_get(), and associates a device with it using
* devres. On driver detach, framer_put() function is invoked on the devres
* data, then, devres data is freed.
*/
struct framer *devm_framer_get(struct device *dev, const char *con_id)
{
struct framer **ptr, *framer;
ptr = devres_alloc(devm_framer_put, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
framer = framer_get(dev, con_id);
if (!IS_ERR(framer)) {
*ptr = framer;
devres_add(dev, ptr);
} else {
devres_free(ptr);
return framer;
}
return framer;
}
EXPORT_SYMBOL_GPL(devm_framer_get);
/**
* devm_framer_optional_get() - lookup and obtain a reference to an optional
* framer.
* @dev: device that requests this framer
* @con_id: name of the framer from device's point of view
*
* Same as devm_framer_get() except that if the framer does not exist, it is not
* considered an error and -ENODEV will not be returned. Instead the NULL framer
* is returned.
*/
struct framer *devm_framer_optional_get(struct device *dev, const char *con_id)
{
struct framer *framer = devm_framer_get(dev, con_id);
if (PTR_ERR(framer) == -ENODEV)
framer = NULL;
return framer;
}
EXPORT_SYMBOL_GPL(devm_framer_optional_get);
static void framer_notify_status_work(struct work_struct *work)
{
struct framer *framer = container_of(work, struct framer, notify_status_work);
blocking_notifier_call_chain(&framer->notifier_list, FRAMER_EVENT_STATUS, NULL);
}
void framer_notify_status_change(struct framer *framer)
{
/* Can be called from atomic context -> just schedule a task to call
* blocking notifiers
*/
queue_work(system_power_efficient_wq, &framer->notify_status_work);
}
EXPORT_SYMBOL_GPL(framer_notify_status_change);
/**
* framer_create() - create a new framer
* @dev: device that is creating the new framer
* @node: device node of the framer. default to dev->of_node.
* @ops: function pointers for performing framer operations
*
* Called to create a framer using framer framework.
*/
struct framer *framer_create(struct device *dev, struct device_node *node,
const struct framer_ops *ops)
{
struct framer *framer;
int ret;
int id;
/* get_status() is mandatory if the provider ask for polling status */
if (WARN_ON((ops->flags & FRAMER_FLAG_POLL_STATUS) && !ops->get_status))
return ERR_PTR(-EINVAL);
framer = kzalloc(sizeof(*framer), GFP_KERNEL);
if (!framer)
return ERR_PTR(-ENOMEM);
id = ida_alloc(&framer_ida, GFP_KERNEL);
if (id < 0) {
dev_err(dev, "unable to get id\n");
ret = id;
goto free_framer;
}
device_initialize(&framer->dev);
mutex_init(&framer->mutex);
INIT_WORK(&framer->notify_status_work, framer_notify_status_work);
INIT_DELAYED_WORK(&framer->polling_work, framer_polling_work);
BLOCKING_INIT_NOTIFIER_HEAD(&framer->notifier_list);
framer->dev.class = &framer_class;
framer->dev.parent = dev;
framer->dev.of_node = node ? node : dev->of_node;
framer->id = id;
framer->ops = ops;
ret = dev_set_name(&framer->dev, "framer-%s.%d", dev_name(dev), id);
if (ret)
goto put_dev;
/* framer-supply */
framer->pwr = regulator_get_optional(&framer->dev, "framer");
if (IS_ERR(framer->pwr)) {
ret = PTR_ERR(framer->pwr);
if (ret == -EPROBE_DEFER)
goto put_dev;
framer->pwr = NULL;
}
ret = device_add(&framer->dev);
if (ret)
goto put_dev;
if (pm_runtime_enabled(dev)) {
pm_runtime_enable(&framer->dev);
pm_runtime_no_callbacks(&framer->dev);
}
return framer;
put_dev:
put_device(&framer->dev); /* calls framer_release() which frees resources */
return ERR_PTR(ret);
free_framer:
kfree(framer);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(framer_create);
/**
* framer_destroy() - destroy the framer
* @framer: the framer to be destroyed
*
* Called to destroy the framer.
*/
void framer_destroy(struct framer *framer)
{
/* polling_work should already be stopped but if framer_exit() was not
* called (bug), here it's the last time to do that ...
*/
cancel_delayed_work_sync(&framer->polling_work);
cancel_work_sync(&framer->notify_status_work);
pm_runtime_disable(&framer->dev);
device_unregister(&framer->dev); /* calls framer_release() which frees resources */
}
EXPORT_SYMBOL_GPL(framer_destroy);
static void devm_framer_destroy(struct device *dev, void *res)
{
struct framer *framer = *(struct framer **)res;
framer_destroy(framer);
}
/**
* devm_framer_create() - create a new framer
* @dev: device that is creating the new framer
* @node: device node of the framer
* @ops: function pointers for performing framer operations
*
* Creates a new framer device adding it to the framer class.
* While at that, it also associates the device with the framer using devres.
* On driver detach, release function is invoked on the devres data,
* then, devres data is freed.
*/
struct framer *devm_framer_create(struct device *dev, struct device_node *node,
const struct framer_ops *ops)
{
struct framer **ptr, *framer;
ptr = devres_alloc(devm_framer_destroy, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
framer = framer_create(dev, node, ops);
if (!IS_ERR(framer)) {
*ptr = framer;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return framer;
}
EXPORT_SYMBOL_GPL(devm_framer_create);
/**
* framer_provider_simple_of_xlate() - returns the framer instance from framer provider
* @dev: the framer provider device
* @args: of_phandle_args (not used here)
*
* Intended to be used by framer provider for the common case where #framer-cells is
* 0. For other cases where #framer-cells is greater than '0', the framer provider
* should provide a custom of_xlate function that reads the *args* and returns
* the appropriate framer.
*/
struct framer *framer_provider_simple_of_xlate(struct device *dev,
const struct of_phandle_args *args)
{
struct class_dev_iter iter;
struct framer *framer;
class_dev_iter_init(&iter, &framer_class, NULL, NULL);
while ((dev = class_dev_iter_next(&iter))) {
framer = dev_to_framer(dev);
if (args->np != framer->dev.of_node)
continue;
class_dev_iter_exit(&iter);
return framer;
}
class_dev_iter_exit(&iter);
return ERR_PTR(-ENODEV);
}
EXPORT_SYMBOL_GPL(framer_provider_simple_of_xlate);
/**
* __framer_provider_of_register() - create/register framer provider with the framework
* @dev: struct device of the framer provider
* @owner: the module owner containing of_xlate
* @of_xlate: function pointer to obtain framer instance from framer provider
*
* Creates struct framer_provider from dev and of_xlate function pointer.
* This is used in the case of dt boot for finding the framer instance from
* framer provider.
*/
struct framer_provider *
__framer_provider_of_register(struct device *dev, struct module *owner,
struct framer *(*of_xlate)(struct device *dev,
const struct of_phandle_args *args))
{
struct framer_provider *framer_provider;
framer_provider = kzalloc(sizeof(*framer_provider), GFP_KERNEL);
if (!framer_provider)
return ERR_PTR(-ENOMEM);
framer_provider->dev = dev;
framer_provider->owner = owner;
framer_provider->of_xlate = of_xlate;
of_node_get(framer_provider->dev->of_node);
mutex_lock(&framer_provider_mutex);
list_add_tail(&framer_provider->list, &framer_provider_list);
mutex_unlock(&framer_provider_mutex);
return framer_provider;
}
EXPORT_SYMBOL_GPL(__framer_provider_of_register);
/**
* framer_provider_of_unregister() - unregister framer provider from the framework
* @framer_provider: framer provider returned by framer_provider_of_register()
*
* Removes the framer_provider created using framer_provider_of_register().
*/
void framer_provider_of_unregister(struct framer_provider *framer_provider)
{
mutex_lock(&framer_provider_mutex);
list_del(&framer_provider->list);
mutex_unlock(&framer_provider_mutex);
of_node_put(framer_provider->dev->of_node);
kfree(framer_provider);
}
EXPORT_SYMBOL_GPL(framer_provider_of_unregister);
static void devm_framer_provider_of_unregister(struct device *dev, void *res)
{
struct framer_provider *framer_provider = *(struct framer_provider **)res;
framer_provider_of_unregister(framer_provider);
}
/**
* __devm_framer_provider_of_register() - create/register framer provider with
* the framework
* @dev: struct device of the framer provider
* @owner: the module owner containing of_xlate
* @of_xlate: function pointer to obtain framer instance from framer provider
*
* Creates struct framer_provider from dev and of_xlate function pointer.
* This is used in the case of dt boot for finding the framer instance from
* framer provider. While at that, it also associates the device with the
* framer provider using devres. On driver detach, release function is invoked
* on the devres data, then, devres data is freed.
*/
struct framer_provider *
__devm_framer_provider_of_register(struct device *dev, struct module *owner,
struct framer *(*of_xlate)(struct device *dev,
const struct of_phandle_args *args))
{
struct framer_provider **ptr, *framer_provider;
ptr = devres_alloc(devm_framer_provider_of_unregister, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
framer_provider = __framer_provider_of_register(dev, owner, of_xlate);
if (!IS_ERR(framer_provider)) {
*ptr = framer_provider;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return framer_provider;
}
EXPORT_SYMBOL_GPL(__devm_framer_provider_of_register);
/**
* framer_release() - release the framer
* @dev: the dev member within framer
*
* When the last reference to the device is removed, it is called
* from the embedded kobject as release method.
*/
static void framer_release(struct device *dev)
{
struct framer *framer;
framer = dev_to_framer(dev);
regulator_put(framer->pwr);
ida_free(&framer_ida, framer->id);
kfree(framer);
}
static int __init framer_core_init(void)
{
return class_register(&framer_class);
}
device_initcall(framer_core_init);
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