[PATCH v4 21/28] net: wan: Add framer framework support

[Christophe JAILLET]

Le 18/08/2023 à 18:39, Christophe Leroy a écrit :
> From: Herve Codina <herve.codina at bootlin.com>
> 
> A framer is a component in charge of an E1/T1 line interface.
> Connected usually to a TDM bus, it converts TDM frames to/from E1/T1
> frames. It also provides information related to the E1/T1 line.
> 
> The framer framework provides a set of APIs for the framer drivers
> (framer provider) to create/destroy a framer and APIs for the framer
> users (framer consumer) to obtain a reference to the framer, and
> use the framer.
> 
> This basic implementation provides a framer abstraction for:
>   - power on/off the framer
>   - get the framer status (line state)
>   - be notified on framer status changes
>   - get/set the framer configuration
> 
> Signed-off-by: Herve Codina <herve.codina at bootlin.com>
> Reviewed-by: Christophe Leroy <christophe.leroy at csgroup.eu>
> Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
> ---

Hi,

should there be a V5, some nits below.

...

> +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);

                      ~~
Useless extra space

> +		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;
> +}

...

> +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);

ida_alloc()?
(ida_simple_get() is deprecated)

> +	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);
> +}

...

> +void framer_provider_of_unregister(struct framer_provider *framer_provider)
> +{
> +	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);

If it make sense, of_node_put() and kfree() could maybe be out of the 
mutex, in order to match how things are done in 
__framer_provider_of_register().

> +}

...

> +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);

ida_free()?
(ida_simple_remove() is deprecated)

> +	kfree(framer);
> +}

...