| Message ID | 1614254912-15746-1-git-send-email-shengjiu.wang@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ASoC: simple-card: Add dummy dai support simple sound card | expand |
On Thu, Feb 25, 2021 at 08:08:32PM +0800, Shengjiu Wang wrote: > If sound card doesn't need specific codec device, just > dummy codec is enough, then we can link the dummy component > directly. This is a big red flag - what circumstances are these? If it's a simple CODEC with no control then the general approach is to provide a driver which announces the capabilities of the CODEC and can be bound to as normal, the dummy component should never actively be used.
On Thu, Feb 25, 2021 at 9:17 PM Mark Brown <broonie@kernel.org> wrote: > > On Thu, Feb 25, 2021 at 08:08:32PM +0800, Shengjiu Wang wrote: > > > If sound card doesn't need specific codec device, just > > dummy codec is enough, then we can link the dummy component > > directly. > > This is a big red flag - what circumstances are these? If it's a simple > CODEC with no control then the general approach is to provide a driver > which announces the capabilities of the CODEC and can be bound to as > normal, the dummy component should never actively be used. For the DMIC, SPDIF, HDMI ARC device or other similar device that there is no codec connected, then dummy codec is just used for registering the sound card. best regards wang shengjiu
On Fri, Feb 26, 2021 at 02:05:29PM +0800, Shengjiu Wang wrote: > On Thu, Feb 25, 2021 at 9:17 PM Mark Brown <broonie@kernel.org> wrote: > > On Thu, Feb 25, 2021 at 08:08:32PM +0800, Shengjiu Wang wrote: > > > If sound card doesn't need specific codec device, just > > > dummy codec is enough, then we can link the dummy component > > > directly. > > This is a big red flag - what circumstances are these? If it's a simple > > CODEC with no control then the general approach is to provide a driver > > which announces the capabilities of the CODEC and can be bound to as > > normal, the dummy component should never actively be used. > For the DMIC, SPDIF, HDMI ARC device or other > similar device that there is no codec connected, then dummy codec is > just used for registering the sound card. There are logical CODECs there, and we already have devices set up for those (like dmic.c for example). All the above cases have at least some constraints from the spec for the interface.
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c index c262281bc64d..8b0cabd1bad1 100644 --- a/sound/soc/generic/simple-card.c +++ b/sound/soc/generic/simple-card.c @@ -34,10 +34,19 @@ static int asoc_simple_parse_dai(struct device_node *node, { struct of_phandle_args args; int ret; + u32 val; if (!node) return 0; + ret = of_property_read_u32(node, DAI, &val); + if (val == 0) { + dlc->of_node = NULL; + dlc->dai_name = "snd-soc-dummy-dai"; + dlc->name = "snd-soc-dummy"; + return 0; + } + /* * Get node via "sound-dai = <&phandle port>" * it will be used as xxx_of_node on soc_bind_dai_link()
If sound card doesn't need specific codec device, just dummy codec is enough, then we can link the dummy component directly. In this case, user needs to specify below setting in devicetree. Previously the sound-dai is a node of codec, now we check if it is zero before parsing the node, zero means dummy component is specified. simple-audio-card,codec { sound-dai = <0>; }; Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> --- sound/soc/generic/simple-card.c | 9 +++++++++ 1 file changed, 9 insertions(+)