Re: [PATCH v2 01/19] mailbox: Add device-managed registration functions

[Bjorn Andersson]

On Mon 17 Dec 07:01 PST 2018, Thierry Reding wrote:

> From: Thierry Reding <treding@xxxxxxxxxx>
> 
> Add device-managed equivalents of the mbox_controller_register() and
> mbox_controller_unregister() functions that can be used to have the
> devres infrastructure automatically unregister mailbox controllers on
> driver probe failure or driver removal. This can help remove a lot of
> boiler plate code from drivers.
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Regards,
Bjorn

> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
>  drivers/mailbox/mailbox.c          | 70 ++++++++++++++++++++++++++++++
>  include/linux/mailbox_controller.h |  5 +++
>  2 files changed, 75 insertions(+)
> 
> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> index 674b35f402f5..eb781e2b19cb 100644
> --- a/drivers/mailbox/mailbox.c
> +++ b/drivers/mailbox/mailbox.c
> @@ -515,3 +515,73 @@ void mbox_controller_unregister(struct mbox_controller *mbox)
>  	mutex_unlock(&con_mutex);
>  }
>  EXPORT_SYMBOL_GPL(mbox_controller_unregister);
> +
> +static void __devm_mbox_controller_unregister(struct device *dev, void *res)
> +{
> +	struct mbox_controller *mbox = res;
> +
> +	mbox_controller_unregister(mbox);
> +}
> +
> +static int devm_mbox_controller_match(struct device *dev, void *res, void *data)
> +{
> +	struct mbox_controller **mbox = res;
> +
> +	if (WARN_ON(!mbox || !*mbox))
> +		return 0;
> +
> +	return *mbox == data;
> +}
> +
> +/**
> + * devm_mbox_controller_register() - managed mbox_controller_register()
> + * @dev: device owning the mailbox controller being registered
> + * @mbox: mailbox controller being registered
> + *
> + * This function adds a device-managed resource that will make sure that the
> + * mailbox controller, which is registered using mbox_controller_register()
> + * as part of this function, will be unregistered along with the rest of
> + * device-managed resources upon driver probe failure or driver removal.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int devm_mbox_controller_register(struct device *dev,
> +				  struct mbox_controller *mbox)
> +{
> +	struct mbox_controller **ptr;
> +	int err;
> +
> +	ptr = devres_alloc(__devm_mbox_controller_unregister, sizeof(*ptr),
> +			   GFP_KERNEL);
> +	if (!ptr)
> +		return -ENOMEM;
> +
> +	err = mbox_controller_register(mbox);
> +	if (err < 0) {
> +		devres_free(ptr);
> +		return err;
> +	}
> +
> +	devres_add(dev, ptr);
> +	*ptr = mbox;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(devm_mbox_controller_register);
> +
> +/**
> + * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
> + * @dev: device owning the mailbox controller being unregistered
> + * @mbox: mailbox controller being unregistered
> + *
> + * This function unregisters the mailbox controller and removes the device-
> + * managed resource that was set up to automatically unregister the mailbox
> + * controller on driver probe failure or driver removal. It's typically not
> + * necessary to call this function.
> + */
> +void devm_mbox_controller_unregister(struct device *dev, struct mbox_controller *mbox)
> +{
> +	WARN_ON(devres_release(dev, __devm_mbox_controller_unregister,
> +			       devm_mbox_controller_match, mbox));
> +}
> +EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister);
> diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
> index 74deadb42d76..9b0b21207345 100644
> --- a/include/linux/mailbox_controller.h
> +++ b/include/linux/mailbox_controller.h
> @@ -131,4 +131,9 @@ void mbox_controller_unregister(struct mbox_controller *mbox); /* can sleep */
>  void mbox_chan_received_data(struct mbox_chan *chan, void *data); /* atomic */
>  void mbox_chan_txdone(struct mbox_chan *chan, int r); /* atomic */
>  
> +int devm_mbox_controller_register(struct device *dev,
> +				  struct mbox_controller *mbox);
> +void devm_mbox_controller_unregister(struct device *dev,
> +				     struct mbox_controller *mbox);
> +
>  #endif /* __MAILBOX_CONTROLLER_H */
> -- 
> 2.19.1
>