Merge tag 'pef2256-framer' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

Linus Walleij says:

====================
Immutable tag for the PEF2256 framer

* tag 'pef2256-framer' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  MAINTAINERS: Add the Lantiq PEF2256 driver entry
  pinctrl: Add support for the Lantic PEF2256 pinmux
  net: wan: framer: Add support for the Lantiq PEF2256 framer
  dt-bindings: net: Add the Lantiq PEF2256 E1/T1/J1 framer
  net: wan: Add framer framework support
====================

Link: https://lore.kernel.org/all/CACRpkdYT1J7noFUhObFgfA60XQAfL4rb=knEmWS__TKKtCMh7Q@mail.gmail.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

8 files changed, 2073 insertions, 0 deletions

diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig
index dcb069dde66b..7dda87756d3f 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 5bec8fae47f8..8119b49d1da9 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-$(CONFIG_LAPBETHER)		+= lapbether.o
diff --git a/drivers/net/wan/framer/Kconfig b/drivers/net/wan/framer/Kconfig
new file mode 100644
index 000000000000..dc83caef9485
--- /dev/null
+++ b/drivers/net/wan/framer/Kconfig
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# FRAMER
+#
+
+menuconfig FRAMER
+	tristate "Framer Subsystem"
+	help
+	  A framer is a component in charge of an E1/T1 line interface.
+	  Connected usually to a TDM bus, it converts TDM frames to/from E1/T1
+	  frames. It also provides information related to the E1/T1 line.
+	  Used with HDLC, the network can be reached through the E1/T1 line.
+
+	  This framework is designed to provide a generic interface for framer
+	  devices present in the kernel. This layer will have the generic
+	  API by which framer drivers can create framer using the framer
+	  framework and framer users can obtain reference to the framer.
+	  All the users of this framework should select this config.
+
+if FRAMER
+
+config GENERIC_FRAMER
+	bool
+
+config FRAMER_PEF2256
+	tristate "Lantiq PEF2256"
+	depends on OF
+	depends on HAS_IOMEM
+	select GENERIC_FRAMER
+	select MFD_CORE
+	select REGMAP_MMIO
+	help
+	  Enable support for the Lantiq PEF2256 (FALC56) framer.
+	  The PEF2256 is a framer and line interface between analog E1/T1/J1
+	  line and a digital PCM bus.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called framer-pef2256.
+
+endif # FRAMER
diff --git a/drivers/net/wan/framer/Makefile b/drivers/net/wan/framer/Makefile
new file mode 100644
index 000000000000..3403f2b14534
--- /dev/null
+++ b/drivers/net/wan/framer/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the framer drivers.
+#
+
+obj-$(CONFIG_GENERIC_FRAMER)			+= framer-core.o
+obj-$(CONFIG_FRAMER_PEF2256)			+= pef2256/
diff --git a/drivers/net/wan/framer/framer-core.c b/drivers/net/wan/framer/framer-core.c
new file mode 100644
index 000000000000..c04dc88bda6c
--- /dev/null
+++ b/drivers/net/wan/framer/framer-core.c
@@ -0,0 +1,882 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic Framer framework.
+ *
+ * Copyright 2023 CS GROUP France
+ *
+ * Author: Herve Codina <herve.codina@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 (!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(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, 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,
+							 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,
+							      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)
+{
+	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/drivers/net/wan/framer/pef2256/Makefile b/drivers/net/wan/framer/pef2256/Makefile
new file mode 100644
index 000000000000..f4d1208dd8a4
--- /dev/null
+++ b/drivers/net/wan/framer/pef2256/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the pef2256 driver.
+#
+
+obj-$(CONFIG_FRAMER_PEF2256)		+= framer-pef2256.o
+
+framer-pef2256-objs	:= pef2256.o
diff --git a/drivers/net/wan/framer/pef2256/pef2256-regs.h b/drivers/net/wan/framer/pef2256/pef2256-regs.h
new file mode 100644
index 000000000000..5d3183c91714
--- /dev/null
+++ b/drivers/net/wan/framer/pef2256/pef2256-regs.h
@@ -0,0 +1,250 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PEF2256 registers definition
+ *
+ * Copyright 2023 CS GROUP France
+ *
+ * Author: Herve Codina <herve.codina@bootlin.com>
+ */
+#ifndef __PEF2256_REGS_H__
+#define __PEF2256_REGS_H__
+
+#include "linux/bitfield.h"
+
+/* Command Register */
+#define PEF2256_CMDR		0x02
+#define PEF2256_CMDR_RRES	BIT(6)
+#define PEF2256_CMDR_XRES	BIT(4)
+#define PEF2256_CMDR_SRES	BIT(0)
+
+/* Interrupt Mask Register 0..5 */
+#define PEF2256_IMR0	        0x14
+#define PEF2256_IMR1	        0x15
+#define PEF2256_IMR2	        0x16
+#define PEF2256_IMR3	        0x17
+#define PEF2256_IMR4	        0x18
+#define PEF2256_IMR5	        0x19
+
+/* Framer Mode Register 0 */
+#define PEF2256_FMR0		0x1C
+#define PEF2256_FMR0_XC_MASK	GENMASK(7, 6)
+#define PEF2256_FMR0_XC_NRZ	FIELD_PREP_CONST(PEF2256_FMR0_XC_MASK, 0x0)
+#define PEF2256_FMR0_XC_CMI	FIELD_PREP_CONST(PEF2256_FMR0_XC_MASK, 0x1)
+#define PEF2256_FMR0_XC_AMI	FIELD_PREP_CONST(PEF2256_FMR0_XC_MASK, 0x2)
+#define PEF2256_FMR0_XC_HDB3	FIELD_PREP_CONST(PEF2256_FMR0_XC_MASK, 0x3)
+#define PEF2256_FMR0_RC_MASK	GENMASK(5, 4)
+#define PEF2256_FMR0_RC_NRZ	FIELD_PREP_CONST(PEF2256_FMR0_RC_MASK, 0x0)
+#define PEF2256_FMR0_RC_CMI	FIELD_PREP_CONST(PEF2256_FMR0_RC_MASK, 0x1)
+#define PEF2256_FMR0_RC_AMI	FIELD_PREP_CONST(PEF2256_FMR0_RC_MASK, 0x2)
+#define PEF2256_FMR0_RC_HDB3	FIELD_PREP_CONST(PEF2256_FMR0_RC_MASK, 0x3)
+
+/* Framer Mode Register 1 */
+#define PEF2256_FMR1		0x1D
+#define PEF2256_FMR1_XFS	BIT(3)
+#define PEF2256_FMR1_ECM	BIT(2)
+/* SSD is defined on 2 bits. The other bit is on SIC1 register */
+#define PEF2256_FMR1_SSD_MASK	GENMASK(1, 1)
+#define PEF2256_FMR1_SSD_2048	FIELD_PREP_CONST(PEF2256_FMR1_SSD_MASK, 0x0)
+#define PEF2256_FMR1_SSD_4096	FIELD_PREP_CONST(PEF2256_FMR1_SSD_MASK, 0x1)
+#define PEF2256_FMR1_SSD_8192	FIELD_PREP_CONST(PEF2256_FMR1_SSD_MASK, 0x0)
+#define PEF2256_FMR1_SSD_16384	FIELD_PREP_CONST(PEF2256_FMR1_SSD_MASK, 0x1)
+
+/* Framer Mode Register 2 */
+#define PEF2256_FMR2			  0x1E
+#define PEF2256_FMR2_RFS_MASK		  GENMASK(7, 6)
+#define PEF2256_FMR2_RFS_DOUBLEFRAME	  FIELD_PREP_CONST(PEF2256_FMR2_RFS_MASK, 0x0)
+#define PEF2256_FMR2_RFS_CRC4_MULTIFRAME  FIELD_PREP_CONST(PEF2256_FMR2_RFS_MASK, 0x2)
+#define PEF2256_FMR2_RFS_AUTO_MULTIFRAME  FIELD_PREP_CONST(PEF2256_FMR2_RFS_MASK, 0x3)
+#define PEF2256_FMR2_AXRA		  BIT(1)
+
+/* Transmit Service Word */
+#define PEF2256_XSW		0x20
+#define PEF2256_XSW_XSIS	BIT(7)
+#define PEF2256_XSW_XTM		BIT(6)
+#define PEF2256_XSW_XY_MASK	GENMASK(5, 0)
+#define PEF2256_XSW_XY(_v)	FIELD_PREP(PEF2256_XSW_XY_MASK, _v)
+
+/* Transmit Spare Bits */
+#define PEF2256_XSP	        0x21
+#define PEF2256_XSP_XSIF	BIT(2)
+
+/* Transmit Control 0..1 */
+#define PEF2256_XC0		0x22
+#define PEF2256_XC1		0x23
+
+/* Receive Control 0 */
+#define PEF2256_RC0		0x24
+#define PEF2256_RC0_SWD		BIT(7)
+#define PEF2256_RC0_ASY4	BIT(6)
+
+/* Receive Control 1 */
+#define PEF2256_RC1		0x25
+
+/* Transmit Pulse Mask 0..1 */
+#define PEF2256_XPM0		0x26
+#define PEF2256_XPM1		0x27
+
+/* Transmit Pulse Mask 2 */
+#define PEF2256_XPM2		0x28
+#define PEF2256_XPM2_XLT	BIT(6)
+
+/* Transparent Service Word Mask */
+#define PEF2256_TSWM		0x29
+
+/* Line Interface Mode 0 */
+#define PEF2256_LIM0		0x36
+#define PEF2256_2X_LIM0_BIT3	BIT(3) /* v2.x, described as a forced '1' bit */
+#define PEF2256_LIM0_MAS	BIT(0)
+
+/* Line Interface Mode 1 */
+#define PEF2256_LIM1		  0x37
+#define PEF2256_12_LIM1_RIL_MASK  GENMASK(6, 4)
+#define PEF2256_12_LIM1_RIL_910	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x0)
+#define PEF2256_12_LIM1_RIL_740	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x1)
+#define PEF2256_12_LIM1_RIL_590	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x2)
+#define PEF2256_12_LIM1_RIL_420	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x3)
+#define PEF2256_12_LIM1_RIL_320	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x4)
+#define PEF2256_12_LIM1_RIL_210	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x5)
+#define PEF2256_12_LIM1_RIL_160	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x6)
+#define PEF2256_12_LIM1_RIL_100	  FIELD_PREP_CONST(PEF2256_12_LIM1_RIL_MASK, 0x7)
+#define PEF2256_2X_LIM1_RIL_MASK  GENMASK(6, 4)
+#define PEF2256_2X_LIM1_RIL_2250  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x0)
+#define PEF2256_2X_LIM1_RIL_1100  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x1)
+#define PEF2256_2X_LIM1_RIL_600	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x2)
+#define PEF2256_2X_LIM1_RIL_350	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x3)
+#define PEF2256_2X_LIM1_RIL_210	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x4)
+#define PEF2256_2X_LIM1_RIL_140	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x5)
+#define PEF2256_2X_LIM1_RIL_100	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x6)
+#define PEF2256_2X_LIM1_RIL_50	  FIELD_PREP_CONST(PEF2256_2X_LIM1_RIL_MASK, 0x7)
+
+/* Pulse Count Detection */
+#define PEF2256_PCD		0x38
+
+ /* Pulse Count Recovery */
+#define PEF2256_PCR		0x39
+
+ /* Line Interface Mode 2 */
+#define PEF2256_LIM2		0x3A
+#define PEF2256_LIM2_SLT_MASK	GENMASK(5, 4)
+#define PEF2256_LIM2_SLT_THR55	FIELD_PREP_CONST(PEF2256_LIM2_SLT_MASK, 0x0)
+#define PEF2256_LIM2_SLT_THR67	FIELD_PREP_CONST(PEF2256_LIM2_SLT_MASK, 0x1)
+#define PEF2256_LIM2_SLT_THR50	FIELD_PREP_CONST(PEF2256_LIM2_SLT_MASK, 0x2)
+#define PEF2256_LIM2_SLT_THR45	FIELD_PREP_CONST(PEF2256_LIM2_SLT_MASK, 0x3)
+#define PEF2256_LIM2_ELT	BIT(2)
+
+/* System Interface Control 1 */
+#define PEF2256_SIC1	          0x3E
+#define PEF2256_SIC1_SSC_MASK	  (BIT(7) |  BIT(3))
+#define PEF2256_SIC1_SSC_2048	  (0)
+#define PEF2256_SIC1_SSC_4096	  BIT(3)
+#define PEF2256_SIC1_SSC_8192	  BIT(7)
+#define PEF2256_SIC1_SSC_16384	  (BIT(7) |  BIT(3))
+/* SSD is defined on 2 bits. The other bit is on FMR1 register */
+#define PEF2256_SIC1_SSD_MASK	  GENMASK(6, 6)
+#define PEF2256_SIC1_SSD_2048	  FIELD_PREP_CONST(PEF2256_SIC1_SSD_MASK, 0x0)
+#define PEF2256_SIC1_SSD_4096	  FIELD_PREP_CONST(PEF2256_SIC1_SSD_MASK, 0x0)
+#define PEF2256_SIC1_SSD_8192	  FIELD_PREP_CONST(PEF2256_SIC1_SSD_MASK, 0x1)
+#define PEF2256_SIC1_SSD_16384	  FIELD_PREP_CONST(PEF2256_SIC1_SSD_MASK, 0x1)
+#define PEF2256_SIC1_RBS_MASK	  GENMASK(5, 4)
+#define PEF2256_SIC1_RBS_2FRAMES  FIELD_PREP_CONST(PEF2256_SIC1_RBS_MASK, 0x0)
+#define PEF2256_SIC1_RBS_1FRAME	  FIELD_PREP_CONST(PEF2256_SIC1_RBS_MASK, 0x1)
+#define PEF2256_SIC1_RBS_96BITS	  FIELD_PREP_CONST(PEF2256_SIC1_RBS_MASK, 0x2)
+#define PEF2256_SIC1_RBS_BYPASS	  FIELD_PREP_CONST(PEF2256_SIC1_RBS_MASK, 0x3)
+#define PEF2256_SIC1_XBS_MASK	  GENMASK(1, 0)
+#define PEF2256_SIC1_XBS_BYPASS	  FIELD_PREP_CONST(PEF2256_SIC1_XBS_MASK, 0x0)
+#define PEF2256_SIC1_XBS_1FRAME	  FIELD_PREP_CONST(PEF2256_SIC1_XBS_MASK, 0x1)
+#define PEF2256_SIC1_XBS_2FRAMES  FIELD_PREP_CONST(PEF2256_SIC1_XBS_MASK, 0x2)
+#define PEF2256_SIC1_XBS_96BITS	  FIELD_PREP_CONST(PEF2256_SIC1_XBS_MASK, 0x3)
+
+/* System Interface Control 2 */
+#define PEF2256_SIC2		0x3F
+#define PEF2256_SIC2_SICS_MASK	GENMASK(3, 1)
+#define PEF2256_SIC2_SICS(_v)	FIELD_PREP(PEF2256_SIC2_SICS_MASK, _v)
+
+/* System Interface Control 3 */
+#define PEF2256_SIC3		0x40
+#define PEF2256_SIC3_RTRI	BIT(5)
+#define PEF2256_SIC3_RESX	BIT(3)
+#define PEF2256_SIC3_RESR	BIT(2)
+
+/* Clock Mode Register 1 */
+#define PEF2256_CMR1			0x44
+#define PEF2256_CMR1_RS_MASK		GENMASK(5, 4)
+#define PEF2256_CMR1_RS_DPLL		FIELD_PREP_CONST(PEF2256_CMR1_RS_MASK, 0x0)
+#define PEF2256_CMR1_RS_DPLL_LOS_HIGH	FIELD_PREP_CONST(PEF2256_CMR1_RS_MASK, 0x1)
+#define PEF2256_CMR1_RS_DCOR_2048	FIELD_PREP_CONST(PEF2256_CMR1_RS_MASK, 0x2)
+#define PEF2256_CMR1_RS_DCOR_8192	FIELD_PREP_CONST(PEF2256_CMR1_RS_MASK, 0x3)
+#define PEF2256_CMR1_DCS		BIT(3)
+
+/* Clock Mode Register 2 */
+#define PEF2256_CMR2		0x45
+#define PEF2256_CMR2_DCOXC	BIT(5)
+
+/* Global Configuration Register */
+#define PEF2256_GCR		0x46
+#define PEF2256_GCR_SCI		BIT(6)
+#define PEF2256_GCR_ECMC	BIT(4)
+
+/* Port Configuration 5 */
+#define PEF2256_PC5		0x84
+#define PEF2256_PC5_CRP         BIT(0)
+
+/* Global Port Configuration 1 */
+#define PEF2256_GPC1			0x85
+#define PEF2256_GPC1_CSFP_MASK		GENMASK(7, 5)
+#define PEF2256_GPC1_CSFP_SEC_IN_HIGH	FIELD_PREP_CONST(PEF2256_GPC1_CSFP_MASK, 0x0)
+#define PEF2256_GPC1_CSFP_SEC_OUT_HIGH	FIELD_PREP_CONST(PEF2256_GPC1_CSFP_MASK, 0x1)
+#define PEF2256_GPC1_CSFP_FSC_OUT_HIGH	FIELD_PREP_CONST(PEF2256_GPC1_CSFP_MASK, 0x2)
+#define PEF2256_GPC1_CSFP_FSC_OUT_LOW	FIELD_PREP_CONST(PEF2256_GPC1_CSFP_MASK, 0x3)
+
+/* Port Configuration 6 */
+#define PEF2256_PC6		0x86
+
+/* Global Counter Mode n=1..8 */
+#define PEF2256_GCM(_n)         (0x92 + (_n) - 1)
+#define PEF2256_GCM1	        0x92
+#define PEF2256_GCM2	        0x93
+#define PEF2256_GCM3	        0x94
+#define PEF2256_GCM4	        0x95
+#define PEF2256_GCM5	        0x96
+#define PEF2256_GCM6	        0x97
+#define PEF2256_GCM7	        0x98
+#define PEF2256_GCM8	        0x99
+
+/* Version Status Register */
+#define PEF2256_VSTR		 0x4A
+#define PEF2256_VSTR_VERSION_12	 0x00
+#define PEF2256_VSTR_VERSION_21	 0x10
+#define PEF2256_VSTR_VERSION_2x	 0x05
+
+/* Framer Receive Status 0 */
+#define PEF2256_FRS0		0x4C
+#define PEF2256_FRS0_LOS	BIT(7)
+#define PEF2256_FRS0_AIS	BIT(6)
+
+/* Interrupt Status Register 0..5 */
+#define PEF2256_ISR(_n)		(0x68 + (_n))
+#define PEF2256_ISR0		0x68
+#define PEF2256_ISR1		0x69
+#define PEF2256_ISR2		0x6A
+#define PEF2256_ISR3		0x6B
+#define PEF2256_ISR4		0x6C
+#define PEF2256_ISR5		0x6D
+
+/* Global Interrupt Status */
+#define PEF2256_GIS		0x6E
+#define PEF2256_GIS_ISR(_n)	BIT(_n)
+
+/* Wafer Identification Register */
+#define PEF2256_WID		   0xEC
+#define PEF2256_12_WID_MASK	   GENMASK(1, 0)
+#define PEF2256_12_WID_VERSION_12  FIELD_PREP_CONST(PEF2256_12_WID_MASK, 0x3)
+#define PEF2256_2X_WID_MASK	   GENMASK(7, 6)
+#define PEF2256_2X_WID_VERSION_21  FIELD_PREP_CONST(PEF2256_2X_WID_MASK, 0x0)
+#define PEF2256_2X_WID_VERSION_22  FIELD_PREP_CONST(PEF2256_2X_WID_MASK, 0x1)
+
+/* IMR2/ISR2 Interrupts common bits */
+#define PEF2256_INT2_AIS	BIT(3)
+#define PEF2256_INT2_LOS	BIT(2)
+
+#endif /* __PEF2256_REGS_H__ */
diff --git a/drivers/net/wan/framer/pef2256/pef2256.c b/drivers/net/wan/framer/pef2256/pef2256.c
new file mode 100644
index 000000000000..4f81053ee4f0
--- /dev/null
+++ b/drivers/net/wan/framer/pef2256/pef2256.c
@@ -0,0 +1,880 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PEF2256 also known as FALC56 driver
+ *
+ * Copyright 2023 CS GROUP France
+ *
+ * Author: Herve Codina <herve.codina@bootlin.com>
+ */
+
+#include <linux/framer/pef2256.h>
+#include <linux/clk.h>
+#include <linux/framer/framer-provider.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include "pef2256-regs.h"
+
+enum pef2256_frame_type {
+	PEF2256_FRAME_E1_DOUBLEFRAME,
+	PEF2256_FRAME_E1_CRC4_MULTIFRAME,
+	PEF2256_FRAME_E1_AUTO_MULTIFRAME,
+	PEF2256_FRAME_T1J1_4FRAME,
+	PEF2256_FRAME_T1J1_12FRAME,
+	PEF2256_FRAME_T1J1_24FRAME,
+	PEF2256_FRAME_T1J1_72FRAME,
+};
+
+struct pef2256 {
+	struct device *dev;
+	struct regmap *regmap;
+	enum pef2256_version version;
+	struct clk *mclk;
+	struct clk *sclkr;
+	struct clk *sclkx;
+	struct gpio_desc *reset_gpio;
+	unsigned long sysclk_rate;
+	u32 data_rate;
+	bool is_tx_falling_edge;
+	bool is_subordinate;
+	enum pef2256_frame_type frame_type;
+	u8 channel_phase;
+	atomic_t carrier;
+	struct framer *framer;
+};
+
+static u8 pef2256_read8(struct pef2256 *pef2256, int offset)
+{
+	int val;
+
+	regmap_read(pef2256->regmap, offset, &val);
+	return val;
+}
+
+static void pef2256_write8(struct pef2256 *pef2256, int offset, u8 val)
+{
+	regmap_write(pef2256->regmap, offset, val);
+}
+
+static void pef2256_clrbits8(struct pef2256 *pef2256, int offset, u8 clr)
+{
+	regmap_clear_bits(pef2256->regmap, offset, clr);
+}
+
+static void pef2256_setbits8(struct pef2256 *pef2256, int offset, u8 set)
+{
+	regmap_set_bits(pef2256->regmap, offset, set);
+}
+
+static void pef2256_clrsetbits8(struct pef2256 *pef2256, int offset, u8 clr, u8 set)
+{
+	regmap_update_bits(pef2256->regmap, offset, clr | set, set);
+}
+
+enum pef2256_version pef2256_get_version(struct pef2256 *pef2256)
+{
+	enum pef2256_version version = PEF2256_VERSION_UNKNOWN;
+	u8 vstr, wid;
+
+	vstr = pef2256_read8(pef2256, PEF2256_VSTR);
+	wid = pef2256_read8(pef2256, PEF2256_WID);
+
+	switch (vstr) {
+	case PEF2256_VSTR_VERSION_12:
+		if ((wid & PEF2256_12_WID_MASK) == PEF2256_12_WID_VERSION_12)
+			version = PEF2256_VERSION_1_2;
+		break;
+	case PEF2256_VSTR_VERSION_2x:
+		switch (wid & PEF2256_2X_WID_MASK) {
+		case PEF2256_2X_WID_VERSION_21:
+			version = PEF2256_VERSION_2_1;
+			break;
+		case PEF2256_2X_WID_VERSION_22:
+			version = PEF2256_VERSION_2_2;
+			break;
+		}
+		break;
+	case PEF2256_VSTR_VERSION_21:
+		version = PEF2256_VERSION_2_1;
+		break;
+	}
+
+	if (version == PEF2256_VERSION_UNKNOWN)
+		dev_err(pef2256->dev, "Unknown version (0x%02x, 0x%02x)\n", vstr, wid);
+
+	return version;
+}
+EXPORT_SYMBOL_GPL(pef2256_get_version);
+
+enum pef2256_gcm_config_item {
+	PEF2256_GCM_CONFIG_1544000 = 0,
+	PEF2256_GCM_CONFIG_2048000,
+	PEF2256_GCM_CONFIG_8192000,
+	PEF2256_GCM_CONFIG_10000000,
+	PEF2256_GCM_CONFIG_12352000,
+	PEF2256_GCM_CONFIG_16384000,
+};
+
+struct pef2256_gcm_config {
+	u8 gcm_12[6];
+	u8 gcm_2x[8];
+};
+
+static const struct pef2256_gcm_config pef2256_gcm_configs[] = {
+	[PEF2256_GCM_CONFIG_1544000] = {
+		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x00, 0x15},
+		.gcm_2x = {0x00, 0x15, 0x00, 0x08, 0x00, 0x3F, 0x9C, 0xDF},
+	},
+	[PEF2256_GCM_CONFIG_2048000] = {
+		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x00, 0x10},
+		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x2F, 0xDB, 0xDF},
+	},
+	[PEF2256_GCM_CONFIG_8192000] = {
+		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x03, 0x10},
+		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x0B, 0xDB, 0xDF},
+	},
+	[PEF2256_GCM_CONFIG_10000000] = {
+		.gcm_12 = {0x90, 0x51, 0x81, 0x8F, 0x04, 0x10},
+		.gcm_2x = {0x40, 0x1B, 0x3D, 0x0A, 0x00, 0x07, 0xC9, 0xDC},
+	},
+	[PEF2256_GCM_CONFIG_12352000] = {
+		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x07, 0x15},
+		.gcm_2x = {0x00, 0x19, 0x00, 0x08, 0x01, 0x0A, 0x98, 0xDA},
+	},
+	[PEF2256_GCM_CONFIG_16384000] = {
+		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x07, 0x10},
+		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x01, 0x0B, 0xDB, 0xDF},
+	},
+};
+
+static int pef2256_setup_gcm(struct pef2256 *pef2256)
+{
+	enum pef2256_gcm_config_item item;
+	unsigned long mclk_rate;
+	const u8 *gcm;
+	int i, count;
+
+	mclk_rate = clk_get_rate(pef2256->mclk);
+	switch (mclk_rate) {
+	case 1544000:
+		item = PEF2256_GCM_CONFIG_1544000;
+		break;
+	case 2048000:
+		item = PEF2256_GCM_CONFIG_2048000;
+		break;
+	case 8192000:
+		item = PEF2256_GCM_CONFIG_8192000;
+		break;
+	case 10000000:
+		item = PEF2256_GCM_CONFIG_10000000;
+		break;
+	case 12352000:
+		item = PEF2256_GCM_CONFIG_12352000;
+		break;
+	case 16384000:
+		item = PEF2256_GCM_CONFIG_16384000;
+		break;
+	default:
+		dev_err(pef2256->dev, "Unsupported v2.x MCLK rate %lu\n", mclk_rate);
+		return -EINVAL;
+	}
+
+	BUILD_BUG_ON(item >= ARRAY_SIZE(pef2256_gcm_configs));
+
+	if (pef2256->version == PEF2256_VERSION_1_2) {
+		gcm = pef2256_gcm_configs[item].gcm_12;
+		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_12);
+	} else {
+		gcm = pef2256_gcm_configs[item].gcm_2x;
+		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_2x);
+	}
+
+	for (i = 0; i < count; i++)
+		pef2256_write8(pef2256, PEF2256_GCM(i + 1), *(gcm + i));
+
+	return 0;
+}
+
+static int pef2256_setup_e1_line(struct pef2256 *pef2256)
+{
+	u8 fmr1, fmr2;
+
+	/* RCLK output : DPLL clock, DCO-X enabled, DCO-X internal ref clock */
+	pef2256_write8(pef2256, PEF2256_CMR1, 0x00);
+
+	/* SCLKR selected, SCLKX selected,
+	 * receive synchro pulse sourced by SYPR,
+	 * transmit synchro pulse sourced by SYPX,
+	 * DCO-X center frequency enabled
+	 */
+	pef2256_write8(pef2256, PEF2256_CMR2, PEF2256_CMR2_DCOXC);
+
+	if (pef2256->is_subordinate) {
+		/* select RCLK source = 2M,  disable switching from RCLK to SYNC */
+		pef2256_clrsetbits8(pef2256, PEF2256_CMR1, PEF2256_CMR1_RS_MASK,
+				    PEF2256_CMR1_RS_DCOR_2048 | PEF2256_CMR1_DCS);
+	}
+
+	/* slave mode, local loop off, mode short-haul
+	 * In v2.x, bit3 is a forced 1 bit in the datasheet -> Need to be set.
+	 */
+	if (pef2256->version == PEF2256_VERSION_1_2)
+		pef2256_write8(pef2256, PEF2256_LIM0, 0x00);
+	else
+		pef2256_write8(pef2256, PEF2256_LIM0, PEF2256_2X_LIM0_BIT3);
+
+	/* "master" mode */
+	if (!pef2256->is_subordinate)
+		pef2256_setbits8(pef2256, PEF2256_LIM0, PEF2256_LIM0_MAS);
+
+	/* analog interface selected, remote loop off */
+	pef2256_write8(pef2256, PEF2256_LIM1, 0x00);
+
+	/* receive input threshold = 0,21V */
+	if (pef2256->version == PEF2256_VERSION_1_2)
+		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_12_LIM1_RIL_MASK,
+				    PEF2256_12_LIM1_RIL_210);
+	else
+		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_2X_LIM1_RIL_MASK,
+				    PEF2256_2X_LIM1_RIL_210);
+
+	/* transmit pulse mask, default value from datasheet
+	 * transmit line in normal operation
+	 */
+	if (pef2256->version == PEF2256_VERSION_1_2)
+		pef2256_write8(pef2256, PEF2256_XPM0, 0x7B);
+	else
+		pef2256_write8(pef2256, PEF2256_XPM0, 0x9C);
+	pef2256_write8(pef2256, PEF2256_XPM1, 0x03);
+	pef2256_write8(pef2256, PEF2256_XPM2, 0x00);
+
+	/* HDB3 coding, no alarm simulation */
+	pef2256_write8(pef2256, PEF2256_FMR0, PEF2256_FMR0_XC_HDB3 | PEF2256_FMR0_RC_HDB3);
+
+	/* E1, frame format, 2 Mbit/s system data rate, no AIS
+	 * transmission to remote end or system interface, payload loop
+	 * off, transmit remote alarm on
+	 */
+	fmr1 = 0x00;
+	fmr2 = PEF2256_FMR2_AXRA;
+	switch (pef2256->frame_type) {
+	case PEF2256_FRAME_E1_DOUBLEFRAME:
+		fmr2 |= PEF2256_FMR2_RFS_DOUBLEFRAME;
+		break;
+	case PEF2256_FRAME_E1_CRC4_MULTIFRAME:
+		fmr1 |= PEF2256_FMR1_XFS;
+		fmr2 |= PEF2256_FMR2_RFS_CRC4_MULTIFRAME;
+		break;
+	case PEF2256_FRAME_E1_AUTO_MULTIFRAME:
+		fmr1 |= PEF2256_FMR1_XFS;
+		fmr2 |= PEF2256_FMR2_RFS_AUTO_MULTIFRAME;
+		break;
+	default:
+		dev_err(pef2256->dev, "Unsupported frame type %d\n", pef2256->frame_type);
+		return -EINVAL;
+	}
+	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_XFS, fmr1);
+	pef2256_write8(pef2256, PEF2256_FMR2, fmr2);
+
+	if (!pef2256->is_subordinate) {
+		/* SEC input, active high */
+		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_SEC_IN_HIGH);
+	} else {
+		/* FSC output, active high */
+		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_FSC_OUT_HIGH);
+	}
+
+	/* SCLKR, SCLKX, RCLK configured to inputs,
+	 * XFMS active low, CLK1 and CLK2 pin configuration
+	 */
+	pef2256_write8(pef2256, PEF2256_PC5, 0x00);
+	pef2256_write8(pef2256, PEF2256_PC6, 0x00);
+
+	/* port RCLK is output */
+	pef2256_setbits8(pef2256, PEF2256_PC5, PEF2256_PC5_CRP);
+
+	return 0;
+}
+
+static void pef2256_setup_e1_los(struct pef2256 *pef2256)
+{
+	/* detection of LOS alarm = 176 pulses (ie (10 + 1) * 16) */
+	pef2256_write8(pef2256, PEF2256_PCD, 10);
+	/* recovery of LOS alarm = 22 pulses (ie 21 + 1) */
+	pef2256_write8(pef2256, PEF2256_PCR, 21);
+	/* E1 default for the receive slicer threshold */
+	pef2256_write8(pef2256, PEF2256_LIM2, PEF2256_LIM2_SLT_THR50);
+	if (pef2256->is_subordinate) {
+		/* Loop-timed */
+		pef2256_setbits8(pef2256, PEF2256_LIM2, PEF2256_LIM2_ELT);
+	}
+}
+
+static int pef2256_setup_e1_system(struct pef2256 *pef2256)
+{
+	u8 sic1, fmr1;
+
+	/* 2.048 MHz system clocking rate, receive buffer 2 frames, transmit
+	 * buffer bypass, data sampled and transmitted on the falling edge of
+	 * SCLKR/X, automatic freeze signaling, data is active in the first
+	 * channel phase
+	 */
+	pef2256_write8(pef2256, PEF2256_SIC1, 0x00);
+	pef2256_write8(pef2256, PEF2256_SIC2, 0x00);
+	pef2256_write8(pef2256, PEF2256_SIC3, 0x00);
+
+	if (pef2256->is_subordinate) {
+		/* transmit buffer size = 2 frames, transparent mode */
+		pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_XBS_MASK,
+				    PEF2256_SIC1_XBS_2FRAMES);
+	}
+
+	if (pef2256->version != PEF2256_VERSION_1_2) {
+		/* during inactive channel phase switch RDO/RSIG into tri-state */
+		pef2256_setbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RTRI);
+	}
+
+	if (pef2256->is_tx_falling_edge) {
+		/* falling edge sync pulse transmit, rising edge sync pulse receive */
+		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESX, PEF2256_SIC3_RESR);
+	} else {
+		/* rising edge sync pulse transmit, falling edge sync pulse receive */
+		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESR, PEF2256_SIC3_RESX);
+	}
+
+	/* transmit offset counter (XCO10..0) = 4 */
+	pef2256_write8(pef2256, PEF2256_XC0, 0);
+	pef2256_write8(pef2256, PEF2256_XC1, 4);
+	/* receive offset counter (RCO10..0) = 4 */
+	pef2256_write8(pef2256, PEF2256_RC0, 0);
+	pef2256_write8(pef2256, PEF2256_RC1, 4);
+
+	/* system clock rate */
+	switch (pef2256->sysclk_rate) {
+	case 2048000:
+		sic1 = PEF2256_SIC1_SSC_2048;
+		break;
+	case 4096000:
+		sic1 = PEF2256_SIC1_SSC_4096;
+		break;
+	case 8192000:
+		sic1 = PEF2256_SIC1_SSC_8192;
+		break;
+	case 16384000:
+		sic1 = PEF2256_SIC1_SSC_16384;
+		break;
+	default:
+		dev_err(pef2256->dev, "Unsupported sysclk rate %lu\n", pef2256->sysclk_rate);
+		return -EINVAL;
+	}
+	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSC_MASK, sic1);
+
+	/* data clock rate */
+	switch (pef2256->data_rate) {
+	case 2048000:
+		fmr1 = PEF2256_FMR1_SSD_2048;
+		sic1 = PEF2256_SIC1_SSD_2048;
+		break;
+	case 4096000:
+		fmr1 = PEF2256_FMR1_SSD_4096;
+		sic1 = PEF2256_SIC1_SSD_4096;
+		break;
+	case 8192000:
+		fmr1 = PEF2256_FMR1_SSD_8192;
+		sic1 = PEF2256_SIC1_SSD_8192;
+		break;
+	case 16384000:
+		fmr1 = PEF2256_FMR1_SSD_16384;
+		sic1 = PEF2256_SIC1_SSD_16384;
+		break;
+	default:
+		dev_err(pef2256->dev, "Unsupported data rate %u\n", pef2256->data_rate);
+		return -EINVAL;
+	}
+	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_SSD_MASK, fmr1);
+	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSD_MASK, sic1);
+
+	/* channel phase */
+	pef2256_clrsetbits8(pef2256, PEF2256_SIC2, PEF2256_SIC2_SICS_MASK,
+			    PEF2256_SIC2_SICS(pef2256->channel_phase));
+
+	return 0;
+}
+
+static void pef2256_setup_e1_signaling(struct pef2256 *pef2256)
+{
+	/* All bits of the transmitted service word are cleared */
+	pef2256_write8(pef2256, PEF2256_XSW, PEF2256_XSW_XY(0x1F));
+
+	/* CAS disabled and clear spare bit values */
+	pef2256_write8(pef2256, PEF2256_XSP, 0x00);
+
+	if (pef2256->is_subordinate) {
+		/* transparent mode */
+		pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XTM);
+	}
+
+	/* Si-Bit, Spare bit For International, FAS word */
+	pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XSIS);
+	pef2256_setbits8(pef2256, PEF2256_XSP, PEF2256_XSP_XSIF);
+
+	/* no transparent mode active */
+	pef2256_write8(pef2256, PEF2256_TSWM, 0x00);
+}
+
+static void pef2256_setup_e1_errors(struct pef2256 *pef2256)
+{
+	/* error counter latched every 1s */
+	pef2256_setbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_ECM);
+
+	/* error counter mode COFA */
+	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_ECMC);
+
+	/* errors in service words have no influence */
+	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_SWD);
+
+	/* 4 consecutive incorrect FAS causes loss of sync */
+	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_ASY4);
+}
+
+static int pef2256_setup_e1(struct pef2256 *pef2256)
+{
+	int ret;
+
+	/* Setup, Master clocking mode (GCM8..1) */
+	ret = pef2256_setup_gcm(pef2256);
+	if (ret)
+		return ret;
+
+	/* Select E1 mode */
+	pef2256_write8(pef2256, PEF2256_FMR1, 0x00);
+
+	/* internal second timer, power on */
+	pef2256_write8(pef2256, PEF2256_GCR, 0x00);
+
+	/* Setup line interface */
+	ret = pef2256_setup_e1_line(pef2256);
+	if (ret)
+		return ret;
+
+	/* Setup Loss-of-signal detection and recovery */
+	pef2256_setup_e1_los(pef2256);
+
+	/* Setup system interface */
+	ret = pef2256_setup_e1_system(pef2256);
+	if (ret)
+		return ret;
+
+	/* Setup signaling */
+	pef2256_setup_e1_signaling(pef2256);
+
+	/* Setup errors counters and condition */
+	pef2256_setup_e1_errors(pef2256);
+
+	/* status changed interrupt at both up and down */
+	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_SCI);
+
+	/* Clear any ISR2 pending interrupts and unmask needed interrupts */
+	pef2256_read8(pef2256, PEF2256_ISR2);
+	pef2256_clrbits8(pef2256, PEF2256_IMR2, PEF2256_INT2_LOS | PEF2256_INT2_AIS);
+
+	/* reset lines */
+	pef2256_write8(pef2256, PEF2256_CMDR, PEF2256_CMDR_RRES | PEF2256_CMDR_XRES);
+	return 0;
+}
+
+static void pef2256_isr_default_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
+{
+	dev_warn_ratelimited(pef2256->dev, "ISR%u: 0x%02x not handled\n", nbr, isr);
+}
+
+static bool pef2256_is_carrier_on(struct pef2256 *pef2256)
+{
+	u8 frs0;
+
+	frs0 = pef2256_read8(pef2256, PEF2256_FRS0);
+	return !(frs0 & (PEF2256_FRS0_LOS | PEF2256_FRS0_AIS));
+}
+
+static void pef2256_isr2_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
+{
+	bool carrier;
+
+	if (isr & (PEF2256_INT2_LOS | PEF2256_INT2_AIS)) {
+		carrier = pef2256_is_carrier_on(pef2256);
+		if (atomic_xchg(&pef2256->carrier, carrier) != carrier)
+			framer_notify_status_change(pef2256->framer);
+	}
+}
+
+static irqreturn_t pef2256_irq_handler(int irq, void *priv)
+{
+	static void (*pef2256_isr_handler[])(struct pef2256 *, u8, u8) = {
+		[0] = pef2256_isr_default_handler,
+		[1] = pef2256_isr_default_handler,
+		[2] = pef2256_isr2_handler,
+		[3] = pef2256_isr_default_handler,
+		[4] = pef2256_isr_default_handler,
+		[5] = pef2256_isr_default_handler
+	};
+	struct pef2256 *pef2256 = (struct pef2256 *)priv;
+	u8 gis;
+	u8 isr;
+	u8 n;
+
+	gis = pef2256_read8(pef2256, PEF2256_GIS);
+
+	for (n = 0; n < ARRAY_SIZE(pef2256_isr_handler); n++) {
+		if (gis & PEF2256_GIS_ISR(n)) {
+			isr = pef2256_read8(pef2256, PEF2256_ISR(n));
+			pef2256_isr_handler[n](pef2256, n, isr);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int pef2256_check_rates(struct pef2256 *pef2256, unsigned long sysclk_rate,
+			       unsigned long data_rate)
+{
+	unsigned long rate;
+
+	switch (sysclk_rate) {
+	case 2048000:
+	case 4096000:
+	case 8192000:
+	case 16384000:
+		break;
+	default:
+		dev_err(pef2256->dev, "Unsupported system clock rate %lu\n", sysclk_rate);
+		return -EINVAL;
+	}
+
+	for (rate = data_rate; rate <= data_rate * 4; rate *= 2) {
+		if (rate == sysclk_rate)
+			return 0;
+	}
+	dev_err(pef2256->dev, "Unsupported data rate %lu with system clock rate %lu\n",
+		data_rate, sysclk_rate);
+	return -EINVAL;
+}
+
+static int pef2556_of_parse(struct pef2256 *pef2256, struct device_node *np)
+{
+	int ret;
+
+	pef2256->data_rate = 2048000;
+	ret = of_property_read_u32(np, "lantiq,data-rate-bps", &pef2256->data_rate);
+	if (ret && ret != -EINVAL) {
+		dev_err(pef2256->dev, "%pOF: failed to read lantiq,data-rate-bps\n", np);
+		return ret;
+	}
+
+	ret =  pef2256_check_rates(pef2256, pef2256->sysclk_rate, pef2256->data_rate);
+	if (ret)
+		return ret;
+
+	pef2256->is_tx_falling_edge = of_property_read_bool(np, "lantiq,clock-falling-edge");
+
+	pef2256->channel_phase = 0;
+	ret = of_property_read_u8(np, "lantiq,channel-phase", &pef2256->channel_phase);
+	if (ret && ret != -EINVAL) {
+		dev_err(pef2256->dev, "%pOF: failed to read lantiq,channel-phase\n",
+			np);
+		return ret;
+	}
+	if (pef2256->channel_phase >= pef2256->sysclk_rate / pef2256->data_rate) {
+		dev_err(pef2256->dev, "%pOF: Invalid lantiq,channel-phase %u\n",
+			np, pef2256->channel_phase);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct regmap_config pef2256_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 8,
+	.max_register = 0xff,
+};
+
+static const struct mfd_cell pef2256_devs[] = {
+	{ .name = "lantiq-pef2256-pinctrl", },
+};
+
+static int pef2256_add_audio_devices(struct pef2256 *pef2256)
+{
+	const char *compatible = "lantiq,pef2256-codec";
+	struct mfd_cell *audio_devs;
+	struct device_node *np;
+	unsigned int count = 0;
+	unsigned int i;
+	int ret;
+
+	for_each_available_child_of_node(pef2256->dev->of_node, np) {
+		if (of_device_is_compatible(np, compatible))
+			count++;
+	}
+
+	if (!count)
+		return 0;
+
+	audio_devs = kcalloc(count, sizeof(*audio_devs), GFP_KERNEL);
+	if (!audio_devs)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		audio_devs[i].name = "framer-codec";
+		audio_devs[i].of_compatible = compatible;
+		audio_devs[i].id = i;
+	}
+
+	ret = mfd_add_devices(pef2256->dev, 0, audio_devs, count, NULL, 0, NULL);
+	kfree(audio_devs);
+	return ret;
+}
+
+static int pef2256_framer_get_status(struct framer *framer, struct framer_status *status)
+{
+	struct pef2256 *pef2256 = framer_get_drvdata(framer);
+
+	status->link_is_on = !!atomic_read(&pef2256->carrier);
+	return 0;
+}
+
+static int pef2256_framer_set_config(struct framer *framer, const struct framer_config *config)
+{
+	struct pef2256 *pef2256 = framer_get_drvdata(framer);
+
+	if (config->iface != FRAMER_IFACE_E1) {
+		dev_err(pef2256->dev, "Only E1 line is currently supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	switch (config->clock_type) {
+	case FRAMER_CLOCK_EXT:
+		pef2256->is_subordinate = true;
+		break;
+	case FRAMER_CLOCK_INT:
+		pef2256->is_subordinate = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Apply the new settings */
+	return pef2256_setup_e1(pef2256);
+}
+
+static int pef2256_framer_get_config(struct framer *framer, struct framer_config *config)
+{
+	struct pef2256 *pef2256 = framer_get_drvdata(framer);
+
+	config->iface = FRAMER_IFACE_E1;
+	config->clock_type = pef2256->is_subordinate ? FRAMER_CLOCK_EXT : FRAMER_CLOCK_INT;
+	config->line_clock_rate = 2048000;
+	return 0;
+}
+
+static const struct framer_ops pef2256_framer_ops = {
+	.owner = THIS_MODULE,
+	.get_status = pef2256_framer_get_status,
+	.get_config = pef2256_framer_get_config,
+	.set_config = pef2256_framer_set_config,
+};
+
+static int pef2256_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	unsigned long sclkr_rate, sclkx_rate;
+	struct framer_provider *framer_provider;
+	struct pef2256 *pef2256;
+	const char *version_txt;
+	void __iomem *iomem;
+	int ret;
+	int irq;
+
+	pef2256 = devm_kzalloc(&pdev->dev, sizeof(*pef2256), GFP_KERNEL);
+	if (!pef2256)
+		return -ENOMEM;
+
+	pef2256->dev = &pdev->dev;
+	atomic_set(&pef2256->carrier, 0);
+
+	pef2256->is_subordinate = true;
+	pef2256->frame_type = PEF2256_FRAME_E1_DOUBLEFRAME;
+
+	iomem = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(iomem))
+		return PTR_ERR(iomem);
+
+	pef2256->regmap = devm_regmap_init_mmio(&pdev->dev, iomem,
+						&pef2256_regmap_config);
+	if (IS_ERR(pef2256->regmap)) {
+		dev_err(&pdev->dev, "Failed to initialise Regmap (%ld)\n",
+			PTR_ERR(pef2256->regmap));
+		return PTR_ERR(pef2256->regmap);
+	}
+
+	pef2256->mclk = devm_clk_get_enabled(&pdev->dev, "mclk");
+	if (IS_ERR(pef2256->mclk))
+		return PTR_ERR(pef2256->mclk);
+
+	pef2256->sclkr = devm_clk_get_enabled(&pdev->dev, "sclkr");
+	if (IS_ERR(pef2256->sclkr))
+		return PTR_ERR(pef2256->sclkr);
+
+	pef2256->sclkx = devm_clk_get_enabled(&pdev->dev, "sclkx");
+	if (IS_ERR(pef2256->sclkx))
+		return PTR_ERR(pef2256->sclkx);
+
+	/* Both SCLKR (receive) and SCLKX (transmit) must have the same rate,
+	 * stored as sysclk_rate.
+	 * The exact value will be checked at pef2256_check_rates()
+	 */
+	sclkr_rate = clk_get_rate(pef2256->sclkr);
+	sclkx_rate = clk_get_rate(pef2256->sclkx);
+	if (sclkr_rate != sclkx_rate) {
+		dev_err(pef2256->dev, "clk rate mismatch. sclkr %lu Hz, sclkx %lu Hz\n",
+			sclkr_rate, sclkx_rate);
+		return -EINVAL;
+	}
+	pef2256->sysclk_rate = sclkr_rate;
+
+	/* Reset the component. The MCLK clock must be active during reset */
+	pef2256->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(pef2256->reset_gpio))
+		return PTR_ERR(pef2256->reset_gpio);
+	if (pef2256->reset_gpio) {
+		gpiod_set_value_cansleep(pef2256->reset_gpio, 1);
+		usleep_range(10, 20);
+		gpiod_set_value_cansleep(pef2256->reset_gpio, 0);
+		usleep_range(10, 20);
+	}
+
+	pef2256->version = pef2256_get_version(pef2256);
+	switch (pef2256->version) {
+	case PEF2256_VERSION_1_2:
+		version_txt = "1.2";
+		break;
+	case PEF2256_VERSION_2_1:
+		version_txt = "2.1";
+		break;
+	case PEF2256_VERSION_2_2:
+		version_txt = "2.2";
+		break;
+	default:
+		return -ENODEV;
+	}
+	dev_info(pef2256->dev, "Version %s detected\n", version_txt);
+
+	ret = pef2556_of_parse(pef2256, np);
+	if (ret)
+		return ret;
+
+	/* Create the framer. It can be used on interrupts */
+	pef2256->framer = devm_framer_create(pef2256->dev, NULL, &pef2256_framer_ops);
+	if (IS_ERR(pef2256->framer))
+		return PTR_ERR(pef2256->framer);
+
+	framer_set_drvdata(pef2256->framer, pef2256);
+
+	/* Disable interrupts */
+	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
+
+	/* Clear any pending interrupts */
+	pef2256_read8(pef2256, PEF2256_ISR0);
+	pef2256_read8(pef2256, PEF2256_ISR1);
+	pef2256_read8(pef2256, PEF2256_ISR2);
+	pef2256_read8(pef2256, PEF2256_ISR3);
+	pef2256_read8(pef2256, PEF2256_ISR4);
+	pef2256_read8(pef2256, PEF2256_ISR5);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	ret = devm_request_irq(pef2256->dev, irq, pef2256_irq_handler, 0, "pef2256", pef2256);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, pef2256);
+
+	ret = mfd_add_devices(pef2256->dev, 0, pef2256_devs,
+			      ARRAY_SIZE(pef2256_devs), NULL, 0, NULL);
+	if (ret) {
+		dev_err(pef2256->dev, "add devices failed (%d)\n", ret);
+		return ret;
+	}
+
+	ret = pef2256_setup_e1(pef2256);
+	if (ret)
+		return ret;
+
+	framer_provider = devm_framer_provider_of_register(pef2256->dev,
+							   framer_provider_simple_of_xlate);
+	if (IS_ERR(framer_provider))
+		return PTR_ERR(framer_provider);
+
+	/* Add audio devices */
+	ret = pef2256_add_audio_devices(pef2256);
+	if (ret < 0) {
+		dev_err(pef2256->dev, "add audio devices failed (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pef2256_remove(struct platform_device *pdev)
+{
+	struct pef2256 *pef2256 = platform_get_drvdata(pdev);
+
+	/* Disable interrupts */
+	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
+	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
+
+	return 0;
+}
+
+static const struct of_device_id pef2256_id_table[] = {
+	{ .compatible = "lantiq,pef2256" },
+	{} /* sentinel */
+};
+MODULE_DEVICE_TABLE(of, pef2256_id_table);
+
+static struct platform_driver pef2256_driver = {
+	.driver = {
+		.name = "lantiq-pef2256",
+		.of_match_table = pef2256_id_table,
+	},
+	.probe = pef2256_probe,
+	.remove = pef2256_remove,
+};
+module_platform_driver(pef2256_driver);
+
+struct regmap *pef2256_get_regmap(struct pef2256 *pef2256)
+{
+	return pef2256->regmap;
+}
+EXPORT_SYMBOL_GPL(pef2256_get_regmap);
+
+MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
+MODULE_DESCRIPTION("PEF2256 driver");
+MODULE_LICENSE("GPL");