linux-media.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Antti Palosaari <crope@iki.fi>
To: Steven Toth <stoth@kernellabs.com>
Cc: linux-media <linux-media@vger.kernel.org>
Subject: Re: GPIO interface between DVB sub-drivers (bridge, demod, tuner)
Date: Fri, 20 Jul 2012 04:43:12 +0300	[thread overview]
Message-ID: <5008B7B0.1020602@iki.fi> (raw)
In-Reply-To: <CALzAhNUmdcd7cE-fcMHJsNk1rTcKXoZR9Oyu+5XciNZQ57EBGQ@mail.gmail.com>

On 07/13/2012 12:07 AM, Steven Toth wrote:
> On Thu, Jul 12, 2012 at 4:49 PM, Steven Toth <stoth@kernellabs.com> wrote:
>> Nobody understands the relationship between the bridge and the
>> sub-component as well as the bridge driver. The current interfaces are
>> limiting in many ways. We solve that today with rather ugly 'attach'
>> structures that are inflexible, for example to set gpios to a default state.
>> Then, once that interface is attached, the bridge effectively loses most of
>> the control to the tuner and/or demod. The result is a large disconnect
>> between the bridge and subcomponents.
>>
>> Why limit any interface extension to GPIOs? Why not make something a
>> little more flexible so we can pass custom messages around?

>> What did you ever decide about the enable/disable of the LNA? And, how
>> would the bridge do that in your proposed solution? Via the proposed GPIO
>> interface?

GPIO / LNA is ready, see following patches:
add LNA support for DVB API
cxd2820r: use Kernel GPIO for GPIO access
em28xx: implement FE set_lna() callback

from:
http://git.linuxtv.org/anttip/media_tree.git/shortlog/refs/heads/dvb_core

Kernel GPIOs were quite easy to implement and use - when needed 
knowledge was gathered after all the testing and study. I wonder why 
none was done that earlier for DVB...

It also offer nice debug/devel feature as you can mount those GPIOs via 
sysfs and use directly.


Next-step: DVB power management.

regards
Antti
-- 
http://palosaari.fi/



  parent reply	other threads:[~2012-07-20  1:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-12 20:24 GPIO interface between DVB sub-drivers (bridge, demod, tuner) Antti Palosaari
     [not found] ` <CALzAhNVwN3TJhn-3i9SDhKfk=tvZZ49RTKkUzWC8RZ_m=v=A+w@mail.gmail.com>
2012-07-12 21:07   ` Steven Toth
2012-07-13  1:13     ` Antti Palosaari
2012-07-13 13:16       ` Steven Toth
2012-07-18  0:22         ` Antti Palosaari
2012-07-20  1:43     ` Antti Palosaari [this message]
2012-07-29 21:21       ` poma
2012-07-30  7:39         ` Antti Palosaari

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5008B7B0.1020602@iki.fi \
    --to=crope@iki.fi \
    --cc=linux-media@vger.kernel.org \
    --cc=stoth@kernellabs.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).