[PATCH v2 20/28] net: wan: Add framer framework support
Christophe Leroy
christophe.leroy at csgroup.eu
Tue Aug 8 18:11:47 AEST 2023
Le 26/07/2023 à 17:02, Herve Codina a écrit :
> A framer is a component in charge of an E1/T1 line interface.
> Connected usually to a TDM bus, it converts TDM frames to/from E1/T1
> frames. It also provides information related to the E1/T1 line.
>
> The framer framework provides a set of APIs for the framer drivers
> (framer provider) to create/destroy a framer and APIs for the framer
> users (framer consumer) to obtain a reference to the framer, and
> use the framer.
>
> This basic implementation provides a framer abstraction for:
> - power on/off the framer
> - get the framer status (line state)
> - be notified on framer status changes
> - get/set the framer configuration
>
> Signed-off-by: Herve Codina <herve.codina at bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy at csgroup.eu>
> ---
> drivers/net/wan/Kconfig | 2 +
> drivers/net/wan/Makefile | 2 +
> drivers/net/wan/framer/Kconfig | 19 +
> drivers/net/wan/framer/Makefile | 6 +
> drivers/net/wan/framer/framer-core.c | 935 +++++++++++++++++++++++++
> include/linux/framer/framer-provider.h | 194 +++++
> include/linux/framer/framer.h | 215 ++++++
> 7 files changed, 1373 insertions(+)
> create mode 100644 drivers/net/wan/framer/Kconfig
> create mode 100644 drivers/net/wan/framer/Makefile
> create mode 100644 drivers/net/wan/framer/framer-core.c
> create mode 100644 include/linux/framer/framer-provider.h
> create mode 100644 include/linux/framer/framer.h
>
> diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig
> index 8de99f4b647b..31ab2136cdf1 100644
> --- a/drivers/net/wan/Kconfig
> +++ b/drivers/net/wan/Kconfig
> @@ -95,6 +95,8 @@ config HDLC_X25
> comment "X.25/LAPB support is disabled"
> depends on HDLC && (LAPB!=m || HDLC!=m) && LAPB!=y
>
> +source "drivers/net/wan/framer/Kconfig"
> +
> config PCI200SYN
> tristate "Goramo PCI200SYN support"
> depends on HDLC && PCI
> diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile
> index f338f4830626..00e9b7ee1e01 100644
> --- a/drivers/net/wan/Makefile
> +++ b/drivers/net/wan/Makefile
> @@ -14,6 +14,8 @@ obj-$(CONFIG_HDLC_FR) += hdlc_fr.o
> obj-$(CONFIG_HDLC_PPP) += hdlc_ppp.o
> obj-$(CONFIG_HDLC_X25) += hdlc_x25.o
>
> +obj-y += framer/
> +
> obj-$(CONFIG_FARSYNC) += farsync.o
>
> obj-$(CONFIG_LAPBETHER) += lapbether.o
> diff --git a/drivers/net/wan/framer/Kconfig b/drivers/net/wan/framer/Kconfig
> new file mode 100644
> index 000000000000..96ef1e7ba8eb
> --- /dev/null
> +++ b/drivers/net/wan/framer/Kconfig
> @@ -0,0 +1,19 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# FRAMER
> +#
> +
> +menu "Framer Subsystem"
> +
> +config GENERIC_FRAMER
> + bool "Framer Core"
> + help
> + Generic Framer support.
> +
> + This framework is designed to provide a generic interface for framer
> + devices present in the kernel. This layer will have the generic
> + API by which framer drivers can create framer using the framer
> + framework and framer users can obtain reference to the framer.
> + All the users of this framework should select this config.
> +
> +endmenu
> diff --git a/drivers/net/wan/framer/Makefile b/drivers/net/wan/framer/Makefile
> new file mode 100644
> index 000000000000..78dbd8e563d0
> --- /dev/null
> +++ b/drivers/net/wan/framer/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Makefile for the framer drivers.
> +#
> +
> +obj-$(CONFIG_GENERIC_FRAMER) += framer-core.o
> diff --git a/drivers/net/wan/framer/framer-core.c b/drivers/net/wan/framer/framer-core.c
> new file mode 100644
> index 000000000000..ef93b7d74fd1
> --- /dev/null
> +++ b/drivers/net/wan/framer/framer-core.c
> @@ -0,0 +1,935 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Generic Framer framework.
> + *
> + * Copyright 2023 CS GROUP France
> + *
> + * Author: Herve Codina <herve.codina at bootlin.com>
> + */
> +
> +#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 struct class *framer_class;
> +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 (!framer)
> + return 0;
> +
> + 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 (!framer)
> + return 0;
> +
> + 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 (!framer)
> + return 0;
> +
> + 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 (!framer)
> + return 0;
> +
> + 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;
> +
> + if (!framer)
> + return 0;
> +
> + 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;
> +
> + if (!framer)
> + return 0;
> +
> + 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 = 0;
> +
> + if (!framer)
> + goto out;
> +
> + if (framer->pwr) {
> + ret = regulator_enable(framer->pwr);
> + if (ret)
> + goto out;
> + }
> +
> + ret = framer_pm_runtime_get_sync(framer);
> + if (ret < 0 && ret != -EOPNOTSUPP)
> + goto err_pm_sync;
> +
> + ret = 0; /* Override possible ret == -EOPNOTSUPP */
> +
> + 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);
> +out:
> + 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;
> +
> + if (!framer)
> + return 0;
> +
> + 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)
> + return -EINVAL;
> +
> + 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)
> + return -EINVAL;
> +
> + 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)
> + return -EINVAL;
> +
> + 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)
> +{
> + if (!framer)
> + return 0;
> +
> + 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)
> +{
> + if (!framer)
> + return -EINVAL;
> +
> + return blocking_notifier_chain_unregister(&framer->notifier_list, nb);
> +}
> +EXPORT_SYMBOL_GPL(framer_atomic_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(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_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)
> +{
> + if (!framer || IS_ERR(framer))
> + return;
> +
> + 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, which can be passed to other framer consumer calls.
> + */
> +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)
> +{
> + if (!framer)
> + return;
> +
> + /* 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)
> +{
> + int ret;
> + int id;
> + struct framer *framer;
> +
> + if (WARN_ON(!dev))
> + return ERR_PTR(-EINVAL);
> +
> + /* 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_simple_get(&framer_ida, 0, 0, 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, struct of_phandle_args *args)
> +{
> + struct framer *framer;
> + struct class_dev_iter iter;
> +
> + 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_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,
> + 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)
> +{
> + if (IS_ERR(framer_provider))
> + return;
> +
> + mutex_lock(&framer_provider_mutex);
> + list_del(&framer_provider->list);
> + of_node_put(framer_provider->dev->of_node);
> + kfree(framer_provider);
> + mutex_unlock(&framer_provider_mutex);
> +}
> +EXPORT_SYMBOL_GPL(of_framer_provider_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,
> + 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_simple_remove(&framer_ida, framer->id);
> + kfree(framer);
> +}
> +
> +static int __init framer_core_init(void)
> +{
> + framer_class = class_create("framer");
> + if (IS_ERR(framer_class)) {
> + pr_err("failed to create framer class (%pe)\n", framer_class);
> + return PTR_ERR(framer_class);
> + }
> +
> + framer_class->dev_release = framer_release;
> +
> + return 0;
> +}
> +device_initcall(framer_core_init);
> diff --git a/include/linux/framer/framer-provider.h b/include/linux/framer/framer-provider.h
> new file mode 100644
> index 000000000000..941a343c3ba7
> --- /dev/null
> +++ b/include/linux/framer/framer-provider.h
> @@ -0,0 +1,194 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Generic framer profider header file
> + *
> + * Copyright 2023 CS GROUP France
> + *
> + * Author: Herve Codina <herve.codina at bootlin.com>
> + */
> +
> +#ifndef __DRIVERS_PROVIDER_FRAMER_H
> +#define __DRIVERS_PROVIDER_FRAMER_H
> +
> +#include <linux/export.h>
> +#include <linux/framer/framer.h>
> +#include <linux/types.h>
> +
> +#define FRAMER_FLAG_POLL_STATUS BIT(0)
> +
> +/**
> + * struct framer_ops - set of function pointers for performing framer operations
> + * @init: operation to be performed for initializing the framer
> + * @exit: operation to be performed while exiting
> + * @power_on: powering on the framer
> + * @power_off: powering off the framer
> + * @flags: OR-ed flags (FRAMER_FLAG_*) to ask for core functionality
> + * - @FRAMER_FLAG_POLL_STATUS:
> + * Ask the core to perfom a polling to get the framer status and
> + * notify consumers on change.
> + * The framer should call @framer_notify_status_change() when it
> + * detects a status change. This is usally done using interrutps.
> + * If the framer cannot detect this change, it can ask the core for
> + * a status polling. The core will call @get_status() periodically
> + * and, on change detected, it will notify the consumer.
> + * the @get_status()
> + * @owner: the module owner containing the ops
> + */
> +struct framer_ops {
> + int (*init)(struct framer *framer);
> + void (*exit)(struct framer *framer);
> + int (*power_on)(struct framer *framer);
> + int (*power_off)(struct framer *framer);
> +
> + /**
> + * @get_status:
> + *
> + * Optional.
> + *
> + * Used to get the framer status. framer_init() must have
> + * been called on the framer.
> + *
> + * Returns: 0 if successful, an negative error code otherwise
> + */
> + int (*get_status)(struct framer *framer, struct framer_status *status);
> +
> + /**
> + * @set_config:
> + *
> + * Optional.
> + *
> + * Used to set the framer configuration. framer_init() must have
> + * been called on the framer.
> + *
> + * Returns: 0 if successful, an negative error code otherwise
> + */
> + int (*set_config)(struct framer *framer, const struct framer_config *config);
> +
> + /**
> + * @get_config:
> + *
> + * Optional.
> + *
> + * Used to get the framer configuration. framer_init() must have
> + * been called on the framer.
> + *
> + * Returns: 0 if successful, an negative error code otherwise
> + */
> + int (*get_config)(struct framer *framer, struct framer_config *config);
> +
> + u32 flags;
> + struct module *owner;
> +};
> +
> +/**
> + * struct framer_provider - represents the framer provider
> + * @dev: framer provider device
> + * @children: can be used to override the default (dev->of_node) child node
> + * @owner: the module owner having of_xlate
> + * @list: to maintain a linked list of framer providers
> + * @of_xlate: function pointer to obtain framer instance from framer pointer
> + */
> +struct framer_provider {
> + struct device *dev;
> + struct module *owner;
> + struct list_head list;
> + struct framer * (*of_xlate)(struct device *dev,
> + struct of_phandle_args *args);
> +};
> +
> +static inline void framer_set_drvdata(struct framer *framer, void *data)
> +{
> + dev_set_drvdata(&framer->dev, data);
> +}
> +
> +static inline void *framer_get_drvdata(struct framer *framer)
> +{
> + return dev_get_drvdata(&framer->dev);
> +}
> +
> +#if IS_ENABLED(CONFIG_GENERIC_FRAMER)
> +
> +/* Create and destroy a framer */
> +struct framer *framer_create(struct device *dev, struct device_node *node,
> + const struct framer_ops *ops);
> +void framer_destroy(struct framer *framer);
> +
> +/* devm version */
> +struct framer *devm_framer_create(struct device *dev, struct device_node *node,
> + const struct framer_ops *ops);
> +
> +struct framer *framer_provider_simple_of_xlate(struct device *dev,
> + struct of_phandle_args *args);
> +
> +struct framer_provider *
> +__framer_provider_of_register(struct device *dev, struct module *owner,
> + struct framer *(*of_xlate)(struct device *dev,
> + struct of_phandle_args *args));
> +
> +void framer_provider_of_unregister(struct framer_provider *framer_provider);
> +
> +struct framer_provider *
> +__devm_framer_provider_of_register(struct device *dev, struct module *owner,
> + struct framer *(*of_xlate)(struct device *dev,
> + struct of_phandle_args *args));
> +
> +void framer_notify_status_change(struct framer *framer);
> +
> +#else /* IS_ENABLED(CONFIG_GENERIC_FRAMER) */
> +
> +static inline struct framer *framer_create(struct device *dev, struct device_node *node,
> + const struct framer_ops *ops)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +static inline void framer_destroy(struct framer *framer)
> +{
> +}
> +
> +/* devm version */
> +static inline struct framer *devm_framer_create(struct device *dev, struct device_node *node,
> + const struct framer_ops *ops)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +static inline struct framer *framer_provider_simple_of_xlate(struct device *dev,
> + struct of_phandle_args *args)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +static inline struct framer_provider *
> +__framer_provider_of_register(struct device *dev, struct module *owner,
> + struct framer *(*of_xlate)(struct device *dev,
> + struct of_phandle_args *args))
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +void framer_provider_of_unregister(struct framer_provider *framer_provider)
> +{
> +}
> +
> +static inline struct framer_provider *
> +__devm_framer_provider_of_register(struct device *dev, struct module *owner,
> + struct framer *(*of_xlate)(struct device *dev,
> + struct of_phandle_args *args))
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +void framer_notify_status_change(struct framer *framer)
> +{
> +}
> +
> +#endif /* IS_ENABLED(CONFIG_GENERIC_FRAMER) */
> +
> +#define framer_provider_of_register(dev, xlate) \
> + __framer_provider_of_register((dev), THIS_MODULE, (xlate))
> +
> +#define devm_framer_provider_of_register(dev, xlate) \
> + __devm_framer_provider_of_register((dev), THIS_MODULE, (xlate))
> +
> +#endif /* __DRIVERS_PROVIDER_FRAMER_H */
> diff --git a/include/linux/framer/framer.h b/include/linux/framer/framer.h
> new file mode 100644
> index 000000000000..b735027f6801
> --- /dev/null
> +++ b/include/linux/framer/framer.h
> @@ -0,0 +1,215 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Generic framer header file
> + *
> + * Copyright 2023 CS GROUP France
> + *
> + * Author: Herve Codina <herve.codina at bootlin.com>
> + */
> +
> +#ifndef __DRIVERS_FRAMER_H
> +#define __DRIVERS_FRAMER_H
> +
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +#include <linux/device.h>
> +#include <linux/workqueue.h>
> +
> +/**
> + * enum framer_iface - Framer interface
> + */
> +enum framer_iface {
> + FRAMER_IFACE_E1, /* E1 interface */
> + FRAMER_IFACE_T1, /* T1 interface */
> +};
> +
> +/**
> + * enum framer_clock_mode - Framer clock mode
> + */
> +enum framer_clock_type {
> + FRAMER_CLOCK_EXT, /* External clock */
> + FRAMER_CLOCK_INT, /* Internal clock */
> +};
> +
> +/**
> + * struct framer_configuration - Framer configuration
> + * @line_iface: Framer line interface
> + * @clock_mode: Framer clock type
> + * @clock_rate: Framer clock rate
> + */
> +struct framer_config {
> + enum framer_iface iface;
> + enum framer_clock_type clock_type;
> + unsigned long line_clock_rate;
> +};
> +
> +/**
> + * struct framer_status - Framer status
> + * @link_is_on: Framer link state. true, the link is on, false, the link is off.
> + */
> +struct framer_status {
> + bool link_is_on;
> +};
> +
> +/**
> + * framer_event - event available for notification
> + */
> +enum framer_event {
> + FRAMER_EVENT_STATUS, /* Event notified on framer_status changes */
> +};
> +
> +/**
> + * struct framer - represents the framer device
> + * @dev: framer device
> + * @id: id of the framer device
> + * @ops: function pointers for performing framer operations
> + * @mutex: mutex to protect framer_ops
> + * @init_count: used to protect when the framer is used by multiple consumers
> + * @power_count: used to protect when the framer is used by multiple consumers
> + * @pwr: power regulator associated with the framer
> + * @polling_task: polling task used if framer notifier operations are not provided
> + * @polling_notifier_list: notifier list used by the polling task
> + * @prev_status: previous read status used by the polling task to detect changes
> + */
> +struct framer {
> + struct device dev;
> + int id;
> + const struct framer_ops *ops;
> + struct mutex mutex; /* Protect framer */
> + int init_count;
> + int power_count;
> + struct regulator *pwr;
> + struct work_struct notify_status_work;
> + struct blocking_notifier_head notifier_list;
> + struct delayed_work polling_work;
> + struct framer_status prev_status;
> +};
> +
> +#if IS_ENABLED(CONFIG_GENERIC_FRAMER)
> +int framer_pm_runtime_get(struct framer *framer);
> +int framer_pm_runtime_get_sync(struct framer *framer);
> +int framer_pm_runtime_put(struct framer *framer);
> +int framer_pm_runtime_put_sync(struct framer *framer);
> +int framer_init(struct framer *framer);
> +int framer_exit(struct framer *framer);
> +int framer_power_on(struct framer *framer);
> +int framer_power_off(struct framer *framer);
> +int framer_get_status(struct framer *framer, struct framer_status *status);
> +int framer_get_config(struct framer *framer, struct framer_config *config);
> +int framer_set_config(struct framer *framer, const struct framer_config *config);
> +int framer_notifier_register(struct framer *framer, struct notifier_block *nb);
> +int framer_notifier_unregister(struct framer *framer, struct notifier_block *nb);
> +
> +struct framer *framer_get(struct device *dev, const char *con_id);
> +void framer_put(struct device *dev, struct framer *framer);
> +
> +struct framer *devm_framer_get(struct device *dev, const char *con_id);
> +struct framer *devm_framer_optional_get(struct device *dev, const char *con_id);
> +#else
> +static inline int framer_pm_runtime_get(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_pm_runtime_get_sync(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_pm_runtime_put(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_pm_runtime_put_sync(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_init(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_exit(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_power_on(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_power_off(struct framer *framer)
> +{
> + if (!framer)
> + return 0;
> + return -ENOSYS;
> +}
> +
> +static inline int framer_get_status(struct framer *framer, struct framer_status *status)
> +{
> + return -ENOSYS;
> +}
> +
> +static inline int framer_get_config(struct framer *framer, struct framer_config *config)
> +{
> + return -ENOSYS;
> +}
> +
> +static inline int framer_set_config(struct framer *framer, const struct framer_config *config)
> +{
> + if (!framer)
> + return 0;
> +
> + return -ENOSYS;
> +}
> +
> +static inline int framer_notifier_register(struct framer *framer,
> + struct notifier_block *nb)
> +{
> + if (!framer)
> + return 0;
> +
> + return -ENOSYS;
> +}
> +
> +static inline int framer_notifier_unregister(struct framer *framer,
> + struct notifier_block *nb)
> +{
> + if (!framer)
> + return 0;
> +
> + return -ENOSYS;
> +}
> +
> +static inline struct framer *devm_framer_get(struct device *dev, const char *con_id)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +static inline struct framer *devm_framer_optional_get(struct device *dev, const char *con_id)
> +{
> + return NULL;
> +}
> +
> +#endif
> +
> +#endif /* __DRIVERS_FRAMER_H */
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