Re: [RFC v2] Another approach to IR

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Andy Walls wrote:
> On Wed, 2009-12-02 at 14:55 -0500, Jarod Wilson wrote:
>> On Dec 2, 2009, at 2:33 PM, Mauro Carvalho Chehab wrote:
>>
>>> Dmitry Torokhov wrote:
>> ...
>>>>>> (for each remote/substream that they can recognize).
>>>>> I'm assuming that, by remote, you're referring to a remote receiver (and not to 
>>>>> the remote itself), right?
>>>> If we could separate by remote transmitter that would be the best I
>>>> think, but I understand that it is rarely possible?
>>> IMHO, the better is to use a separate interface for the IR transmitters,
>>> on the devices that support this feature. There are only a few devices
>>> I'm aware of that are able to transmit IR codes.
>> If I'm thinking clearly, there are only three lirc kernel drivers that
>> support transmit, lirc_mceusb, lirc_zilog and lirc_serial. The mceusb
>> driver was posted, so I won't rehash what it is here. The zilog driver
>> binds to a Zilog z80 microprocessor thingy (iirc) exposed via i2c,
>> found on many Hauppauge v4l/dvb devices (PVR-150, HVR-1600, HD-PVR,
>> etc). The serial driver is fairly self-explanatory as well.
>>
>> There are also a few userspace-driven devices that do transmit, but
>> I'm assuming they're (currently) irrelevant to this discussion.
> 
> 
> I've got the CX23888 integrated IR Rx done and Tx nearly done.  I was
> waiting to see how kfifo and lirc_dev panned out before making the
> interface to userspace.
> 
> The CX23885, CX23418, and CX2584x integrated IR is essentially the same.
> I hope to have CX23885 IR done by Christmas.
> 
> Both of those IR devices are/will be encapsulated in a v4l2_subdevice
> object internally.  I was going to write lirc_v4l glue between the
> v4l2_device/v4l2_subdev_ir_ops and lirc_dev.
> 
> As for the the I2C chips, I was going to go back and encapsulate those
> in the v4l2_subdevice object as well, so then my notional lirc_v4l could
> pick those up too.  The I2C subsystem only allows one binding to an I2C
> client address/name on a bus.  So without some new glue like a notional
> lirc_v4l, it *may* be hard to share between ir-kbd-i2c and lirc_i2c and
> lirc_zilog.

The better is to add the lirc glue at ir-common module. There, we have the support
functions used by all V4L devices, and they'll be expanded to cover also
dvb-usb, as soon as I can find some time to do a patch for it.

Cheers,
Mauro.