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From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Timur Tabi <timur@freescale.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
	alsa-devel@alsa-project.org, Fabio Estevam <festevam@gmail.com>,
	javier.martin@vista-silicon.com,
	Sascha Hauer <kernel@pengutronix.de>
Subject: Re: [PATCH 1/2] ASoC: fsl_ssi: Let it understand mono
Date: Tue, 25 Sep 2012 13:53:59 +0100	[thread overview]
Message-ID: <20120925125359.GH4428@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <50606531.8000606@freescale.com>

On Mon, Sep 24, 2012 at 08:50:41AM -0500, Timur Tabi wrote:
> Mark Brown wrote:
> > In I2S mono just means ignoring the right channel or duplicating the
> > left channel into the right channel at one end of the link or the other.
> > As you say the clocking always has to be for an even number of channels.

> Let me see if I understand this correctly.  In order for I2S mono to work,
> we need the following:

> 1) The I2S controller (the SSI in this case) needs to be programmed to DMA
> data from memory into the left channel only of each frame, and it needs to
> pump dummy data into the right channel.  If it automatically pumps the
> same data into the right channel, then the codec doesn't need to do
> anything.  Otherwise, we need one of these:

> 2a) The codec needs to be programmed to ignore the right channel and
> internally duplicate the left channel into both left and right analog signals.

> 2b) The board needs to be wired such that only the left analog signal gets
> routed to the speakers.

Yes.

      reply	other threads:[~2012-09-25 12:54 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-18 16:03 [PATCH 1/2] ASoC: fsl_ssi: Let it understand mono Fabio Estevam
2012-09-18 16:03 ` [PATCH 2/2] ASoC: cs4270: Remove mono support Fabio Estevam
2012-09-24 13:49   ` Timur Tabi
2012-09-25 12:53   ` Mark Brown
2012-09-25 17:22     ` UAC2 device recognized during boot but won't output sound Joao Bonina
2012-09-18 16:14 ` [PATCH 1/2] ASoC: fsl_ssi: Let it understand mono Timur Tabi
2012-09-19 14:07   ` Fabio Estevam
2012-09-19 21:49     ` Timur Tabi
2012-09-22 14:56       ` Mark Brown
2012-09-24 13:50         ` Timur Tabi
2012-09-25 12:53           ` Mark Brown [this message]

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