Re: Final remote(4) / remote(9) API proposal

["Jared D. McNeill" <jmcneill%invisible.ca@localhost>]

Iain Hibbert wrote:
> On Thu, 9 Oct 2008, Jared D. McNeill wrote:
>
> > Here's the final remote API I'm proposing. Feedback?
> >
> >   typedef uint32_t        remote_addr_t;
>
> this could do with being 48-bits at least (I don't know if the Sony PS3
> Bluetooth remote provides an identifier, but the bdaddr which could be
> otherwise used is 48bit and in the futureworld where everything has an
> IPv6 device I can see it being needed)

I had assumed in the bluetooth configuration that the receiver ID (see 
below) would be the MAC address, and the remote address would be 0. We 
can bump this to 64-bit anyway, though.

> >   typedef uint32_t        remote_command_t;
>
> again, I don't exactly know if this is enough for a HID remote - the only
> information I have 'seems' to show that the PS3 remote provides 11 bytes
> of input data (this is from a posting on the FreeBSD bluetooth list):
>
> Input   id=1 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=1 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=2 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=3 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=4 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=5 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Feature id=6 size=8 count=11 page=Microsoft usage=0x0001, logical range 0..255
> Collection page=Generic_Desktop usage=Game_Pad
>
> but it could just be a bitmask that could be decoded to 88 individual
> events.

Not a problem again to increase the size here. Do you think 64-bits 
would be enough or would you like the command to be eg. a 16-byte 
uint8_t array?

> >   struct remote_info {
> >         char    ri_devid[REMOTE_DEVID_LEN];
> >   };
> >
> >   #define REMOTE_GINFO    _IOR('r', 0, struct remote_info)
>
> so, this would be something like "uirda0-3343" for device ID 3343 sending
> events via uirda0 ?

The intent is to not use device_xname so attach order doesn't matter. My 
ATI receiver reports a serial number of 660808003247 for example, so no 
matter the order of remote or emdtv attachments, I will always know that 
this piece of hardware has generated an event.

> >   struct remote_event {
> >         uint8_t                 re_toggle;
> >         remote_addr_t           re_address;
> >         remote_command_t        re_command;
> >         struct timespec         re_time;
> >   };
>
> you didn't say how events are transmitted out of the /dev/wsremote0, will
> it be possible to extend the event structure in the future?

These are returned when a read for sizeof(struct remote_event) bytes is 
issued. We can extend the event structure later if required simply by 
making it larger.

> I'm not sure what the features are above, but sometimes that is a way to
> set configuration options on the device. I should ignore that for now, but
> it would be nice to leave room in the API for that kind of thing..

Always good to keep those things in mind :)

Cheers,
Jared