Hi, Any updates on this? We can start working in tty_port_register_serdev_device() if that's okay? Thanks, Okash On Wed, Mar 22, 2017 at 01:05:24AM +0100, Samuel Thibault wrote: > Hello, > > So Rob, how do you see this going? Shall we introduce a serdev_device > *tty_port_register_serdev_device(tty, device)? Will you work on it or > should I give it a try? > > Samuel > > Samuel Thibault, on mer. 15 mars 2017 16:03:23 +0100, wrote: > > Rob Herring, on mer. 15 mars 2017 09:45:59 -0500, wrote: > > > On Mon, Mar 13, 2017 at 8:18 PM, Samuel Thibault > > > <samuel.thibault@xxxxxxxxxxxx> wrote: > > > > Samuel Thibault, on mar. 14 mars 2017 01:47:01 +0100, wrote: > > > >> Greg KH, on mar. 14 mars 2017 06:14:04 +0800, wrote: > > > >> > On Mon, Mar 13, 2017 at 10:05:51PM +0000, okash.khawaja@xxxxxxxxx wrote: > > > >> > > This patchset introduces a TTY-based way for the synths to communicate > > > >> > > with devices as an alternate for direct serial comms used by the synths > > > >> > > at the moment. It then migrates some of the synths to the TTY-based > > > >> > > comms. Synths migrated in this patchset are dummy, acntsa, bns and > > > >> > > txprt. > > > >> > > > > >> > What about using the serbus code that is now in the tree? That should > > > >> > make this a lot easier than your patchset from what I can see. > > > >> > > > >> Mmm... AIUI from reading tty_port_register_device_attr, one > > > >> would have to have registered a speakup serdev device driver > > > >> *before* tty_port_register_device_attr gets called, so that > > > >> serdev_tty_port_register matches the driver in the loop of > > > >> of_serdev_register_devices, and no TTY cdev is created? > > > > > > Not exactly. The driver doesn't have to be registered nor loaded, but > > > the device does have to be present so no tty cdev is created. The only > > > way a device is present currently is when a node is in the DT. I > > > expect the x86 folks will be adding ACPI support soon. > > > > Ok, but in our case there is no hardware device that the system can > > see/probe, it's just plugged externally. > > > > > >> That would mean that speakup can not be loaded as a module after ttyS0 > > > >> initialization, that won't fly for our use needs. The line discipline > > > >> mechanism allows us to attach ourself to an existing tty. Could we > > > >> imagine a tty_port function which removes the cdev and tries to register > > > >> the tty port again to serdev? > > > >> > > > >> What we basically need to be able to say on speakup module load is > > > >> e.g. "I'm now attaching a device to ttyS0, use this serdev_device_ops to > > > >> discuss with it". > > > > > > > > That for_each_available_child_of_node loop is really way more complex > > > > than what we need. And what's more, it's not working without CONFIG_OF > > > > (!) > > > > > > > > It would really make sense to me to have a > > > > > > > > serdev_device *tty_port_register_serdev_device(tty, device) > > > > > > > > which unregisters the character device of the tty, and creates instead a > > > > controler with the given device plugged to it. Really much like a line > > > > discipline, but way simpler :) > > > > > > What would trigger calling this function? > > > > From the user point of view, loading the speakup module for the external > > device, typically, with "ttyS0" as module parameter. Then the speakup > > init function can do whatever it needs to achieve this :) _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
