From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH 0/5] ASoC: meson: add hdmitx glue support Date: Wed, 15 May 2019 11:33:17 -0700 Message-ID: <7h7eard0uq.fsf@baylibre.com> References: <20190515131858.32130-1-jbrunet@baylibre.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20190515131858.32130-1-jbrunet@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org To: Mark Brown , Liam Girdwood Cc: Jerome Brunet , alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-amlogic@lists.infradead.org List-Id: alsa-devel@alsa-project.org Jerome Brunet writes: > On the Amlogic SoC, there is a glue between the SoC audio outputs and the > input of the embedded Synopsys HDMI controller. > > On the g12a, this glue is mostly a couple of muxes to select the i2s and > spdif inputs of the hdmi controller. Each of these inputs may have > different hw_params and fmt which makes our life a little bit more > interesting, especially when switching between to active inputs. > > This glue is modeled as codec driver and uses codec-to-codec links to > connect to the Synopsys controller. This allows to use the regular > hdmi-codec driver (used by dw-hdmi i2s). > > To avoid glitches while switching input, the trick is to temporarily > force a disconnection of the mux output, which shutdowns the output dai > link. This also ensure that the stream parameters and fmt are updated > when the output is connected back. Tested-by: Kevin Hilman