Purpose:
Allow the user space application to create and release an rpmsg device by adding
rpmsg ioctrl to the /dev/rpmsg_ctrl interface
Aim:
The current implementation is based on the enumeration of services by the
remote processor to create a new channel and instantiate associated rpmsg device.
There is no solution to create a rpmsg channel on user application request.
If the rpmsg char driver allows adding a new endpoint over an existing channel, it
does not offer the ability to create a new one.
Adding the IOCTRL to instantiate rpmsg channels from the user application will allow
to dynamically create and destroy rpmsg devices. Some examples of use are:
- activate the service at the initiative of the application,
- remove the communication on a specific channel before entering the suspend mode,
- creating a temporary channel for debugging purposes.
Delta vs V1 [1]
- Squah patches 1/4(rpmsg: ctrl: Introduce RPMSG_CREATE_DEV_IOCTL) and
2/4 (rpmsg: ctrl: Introduce RPMSG_RELEASE_DEV_IOCTL).
- Remove the rpmsg device attribue to check if a rpmg device can be released, choose to trust
the application (a similar trust already exists for the bind/unbind interface).
[1] https://patchwork.kernel.org/project/linux-remoteproc/list/?series=494021
How to test it:
- This series can be applied on git/andersson/remoteproc.git for-next branch (dc0e14fa833b)
+ the "Restructure the rpmsg char to decorrelate the control part" series[2]
- to test the ioctrl, a rpmsgexportdev tool is available here:
https://github.com/arnopo/rpmsgexport
[2]https://patchwork.kernel.org/project/linux-remoteproc/list/?series=483793
Arnaud Pouliquen (1):
rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls
drivers/rpmsg/rpmsg_ctrl.c | 37 +++++++++++++++++++++++++++++++++----
include/uapi/linux/rpmsg.h | 10 ++++++++++
2 files changed, 43 insertions(+), 4 deletions(-)
--
2.17.1
