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@bootlin.com --- 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@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@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@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 */