> On Tue, Mar 24, 2020 at 05:34:44AM +0000, Pelle Windestam wrote: > > Hi, > > > > I am trying to develop a simple driver for the rpmsg bus, in order to send > various commands from user space in Linux to a secondary CPU (A Cortex M4). > I'm trying to keep things as simple as possible, so my idea was to create a > driver that just has a few attributes which can be set in /sys which would > trigger commands to be sent to the M4 CPU. I have the communication between > the CPU:s up and running, but where I'm having trouble moving forward is how > to access the "struct rpmsg_device *" that I need in order to communicate > with the endpoint for the M4 CPU from the store/show function of the sysfs > attributes. What my driver does is to register a rpmsg_driver in the init > function: > > > > register_rpmsg_driver(&pwm_rpmsg_driver); > > > > the device_driver member of my rpmsg_driver struct has its groups member > set to my driver attribute groups array: > > static struct rpmsg_driver pwm_rpmsg_driver = { > > .probe = pwm_rpmsg_probe, > > .remove = pwm_rpmsg_remove, > > .callback = pwm_rpmsg_cb, > > .id_table = pwm_rpmsg_device_id_table, > > .drv = { > > .groups = driver_pwm_groups, > > .name = "pwm_rpmsg", > > }, > > }; > > > > My issue is that that I am not sure how to access the struct "rpmsg_device > *" (i.e. from the probe() function) in the show/store functions for the sysfs > attributes, which have a "struct device_driver *" argument: > > That is because you have created a driver attribute, not a device attribute. > Create device attributes and you should be fine, they bind to the device your > driver is passed. Thanks! Changing them to device attributes was a breeze. Now I am slightly confused about the "struct device *" argument to the store/show functions. I was under the impression that this would be the "struct device" in the struct rpmsg_device, (which would let me get the struct rpmsg_device using container_of()?), but it appears to be some completely other device (by looking at the pointer address). I have tried searching the kernel code for similar example, but I have not found anything so far. It feels like I am stumbling a bit in the dark here, looking for my rpmsg_device. //Pelle _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies