From: Jose Abreu <Jose.Abreu@synopsys.com>
To: Lars-Peter Clausen <lars@metafoo.de>,
Jose Abreu <Jose.Abreu@synopsys.com>,
<linux-snps-arc@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
<alsa-devel@alsa-project.org>
Cc: <architt@codeaurora.org>, <airlied@linux.ie>,
<Vineet.Gupta1@synopsys.com>, <Alexey.Brodkin@synopsys.com>,
<lgirdwood@gmail.com>, <CARLOS.PALMINHA@synopsys.com>,
<broonie@kernel.org>, <tiwai@suse.com>
Subject: Re: [alsa-devel] [PATCH 2/5 v4] drm/i2c/adv7511: Add audio support
Date: Mon, 11 Apr 2016 15:08:39 +0100 [thread overview]
Message-ID: <570BAFE7.8040206@synopsys.com> (raw)
In-Reply-To: <570B975C.50702@metafoo.de>
Hi Lars,
On 11-04-2016 13:23, Lars-Peter Clausen wrote:
> On 04/11/2016 01:32 PM, Jose Abreu wrote:
>> Hi Lars,
>>
>>
>> On 11-04-2016 10:33, Lars-Peter Clausen wrote:
>>> On 04/11/2016 11:27 AM, Jose Abreu wrote:
>>>> Hi Lars,
>>>>
>>>>
>>>> On 09-04-2016 16:02, Lars-Peter Clausen wrote:
>>>>> On 04/08/2016 06:12 PM, Jose Abreu wrote:
>>>>> [...]
>>>>>>> [...]
>>>>>>>> +- adi,enable-audio: If set the ADV7511 driver will register a codec interface
>>>>>>>> + into ALSA SoC.
>>>>>>> This is not a description of the hardware.
>>>>>> Is this okay: "adi,enable-audio: Set this boolean parameter if ADV7511
>>>>>> transmitter routes audio signals" ?
>>>>> I don't think we need this property. There is no problem with registering
>>>>> the audio part unconditionally. As long as there is no connection we wont
>>>>> create a sound card that is exposed to userspace.
>>>>>
>>>> This change was suggested by Laurent Pinchart and was introduced in v3. Quoting
>>>> Laurent:
>>>> "The idea is that enabling support for ADV7511 audio in the kernel isn't coupled
>>>> with whether the system includes audio support. It would be confusing, and would
>>>> also waste resources, to create a Linux sound device when no sound channel is
>>>> routed on the board."
>>> I wouldn't care too much about this at this point, the extra amount of
>>> resources required for registering the CODEC (but not the sound card) is
>>> just a few bytes (sizeof(struct snd_soc_codec)).
>>>
>>> Nevertheless what we should do is describe the hardware and from this
>>> information infer whether there is a audio connection or not and if there is
>>> none we might skip registering the CODEC. In my opinion this hardware
>>> description should be modeled using of-graph, having a connection between
>>> the SoC side and the adv7511 SPDIF or I2S port.
>>>
>> You mean something like this:
>>
>> sound_playback: sound_playback {
>> compatible = "simple-audio-card";
>> [...]
>> simple-audio-card,format = "i2s";
>> [...]
>> }
>>
>> adv7511@xx {
>> compatible = "adi,adv7511";
>> [...]
>>
>> ports {
>> [...]
>> /* Audio Output */
>> port@x {
>> reg = <x>;
>> endpoint {
>> remote-endpoint = <&sound_playback>;
>> }
>> }
>> }
>> }
> Yes, something like that. Not exactly like that, but similar. One of the
> core concepts of of-graph is that there is always a description of the
> connection from both sides, this way each side can independently figure out
> where it is connected.
>
> Currently there is also zero support of of-graph in ASoC, so a bit of work
> is required to get this integrated properly.
>
I also believe this would be the better option but in the meantime can't I
integrate the audio like it is being done in the dw-hdmi driver[1]? In this
driver the audio is registered as a sound card and is conditionally built using
Kconfig, just like I was doing in the previous versions. I know you said the
HDMI audio is still an open issue but it seems that for this case it was accepted.
[1] http://lxr.free-electrons.com/source/drivers/gpu/drm/bridge/dw-hdmi-ahb-audio.c
Best regards,
Jose Miguel Abreu
next prev parent reply other threads:[~2016-04-11 14:09 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-07 16:53 [PATCH 0/5 v4] Add I2S/ADV7511 audio support for ARC AXS10x boards Jose Abreu
2016-04-07 16:53 ` [PATCH 1/5 v4] drm/i2c/adv7511: Rename and move to separate folder Jose Abreu
2016-04-07 16:53 ` [PATCH 2/5 v4] drm/i2c/adv7511: Add audio support Jose Abreu
2016-04-08 15:46 ` [alsa-devel] " Lars-Peter Clausen
2016-04-08 16:12 ` Jose Abreu
2016-04-09 15:02 ` Lars-Peter Clausen
2016-04-11 9:27 ` Jose Abreu
2016-04-11 9:33 ` Lars-Peter Clausen
2016-04-11 11:32 ` Jose Abreu
2016-04-11 12:23 ` Lars-Peter Clausen
2016-04-11 14:08 ` Jose Abreu [this message]
2016-04-11 19:34 ` Lars-Peter Clausen
2016-04-07 16:53 ` [PATCH 3/5 v4] ASoC: dwc: Use fifo depth to program FCR Jose Abreu
2016-04-07 17:57 ` Applied "ASoC: dwc: Use fifo depth to program FCR" to the asoc tree Mark Brown
2016-04-07 16:53 ` [PATCH 4/5 v4] ASoC: dwc: Add custom PCM driver Jose Abreu
2016-04-07 17:54 ` kbuild test robot
2016-04-07 16:53 ` [PATCH 5/5 v4] ASoC: dwc: Update DOCUMENTATION for I2S Driver Jose Abreu
2016-04-07 17:53 ` Mark Brown
2016-04-08 10:06 ` Jose Abreu
2016-04-08 15:52 ` [alsa-devel] " Lars-Peter Clausen
2016-04-08 16:08 ` Jose Abreu
2016-04-09 14:55 ` Lars-Peter Clausen
2016-04-11 9:24 ` Jose Abreu
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