On Thursday, October 03, 2013 03:33:56 PM Jarkko Nikula wrote:
> This patch adds alternative way to specify DAI links by using ACPI names.
> ACPI name here is considered to be used as an alias for device name during
> DAI link binding time.
What's DAI?
> Rationale behind this is that device name especially with bus connected
> codecs may not be constant enough to be used in machines with dynamic and
> variable amount of bus controllers due changing bus/adapter number.
>
> One way to solve this problem on ACPI 5 based systems is to use ACPI names
> of those devices that are enumerated by the ACPI subsystem.
>
> For instance, matchine drivers could specify codec in DAI link by using:
> .codec_name = "INT33CA:00",
> instead of
> .codec_name = "rt5640.0-001c",
>
> Note that ACPI name is used just an alias during bind time and core
> continues to use device name. In fact, machine drivers could use either
> names.
>
> Thanks to Mika Westerberg for initial idea to use ACPI handles for binding.
> Author extended and simplified the idea so that struct snd_soc_dai_link
> doesn't need a new field, machine drivers don't need any additional code
> and soc-core.c can handle matching when executing soc_bind_dai_link().
>
> Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> linux-acpi@xxxxxxxxxxxxxxx cc'd if ACPI folks would like to check API usage
> here.
> ---
> sound/soc/soc-core.c | 38 ++++++++++++++++++++++++++++++++------
> 1 file changed, 32 insertions(+), 6 deletions(-)
>
> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> index 4280c70..5cb440e 100644
> --- a/sound/soc/soc-core.c
> +++ b/sound/soc/soc-core.c
> @@ -36,6 +36,7 @@
> #include <linux/of.h>
> #include <linux/gpio.h>
> #include <linux/of_gpio.h>
> +#include <linux/acpi.h>
> #include <sound/ac97_codec.h>
> #include <sound/core.h>
> #include <sound/jack.h>
> @@ -836,6 +837,27 @@ EXPORT_SYMBOL_GPL(snd_soc_resume);
> static const struct snd_soc_dai_ops null_dai_ops = {
> };
>
> +static bool soc_match_name(struct device *dev,
> + const char *comp_name, const char *bind_name)
> +{
> + if (!strcmp(comp_name, bind_name))
> + return true;
> +
> +#if IS_ENABLED(CONFIG_ACPI)
That's not necessary, because ACPI_HANDLE() is defined as false for
CONFIG_ACPI unset.
> + if (ACPI_HANDLE(dev)) {
> + struct acpi_device *adev;
> + if (!acpi_bus_get_device(ACPI_HANDLE(dev), &adev) &&
> + !strcmp(dev_name(&adev->dev), bind_name)) {
> + dev_dbg(dev, "Matching with ACPI name %s\n",
> + dev_name(&adev->dev));
> + return true;
> + }
> + }
> +#endif
> +
> + return false;
> +}
> +
> static int soc_bind_dai_link(struct snd_soc_card *card, int num)
> {
> struct snd_soc_dai_link *dai_link = &card->dai_link[num];
> @@ -853,10 +875,12 @@ static int soc_bind_dai_link(struct snd_soc_card *card, int num)
> (cpu_dai->dev->of_node != dai_link->cpu_of_node))
> continue;
> if (dai_link->cpu_name &&
> - strcmp(dev_name(cpu_dai->dev), dai_link->cpu_name))
> + !soc_match_name(cpu_dai->dev, dev_name(cpu_dai->dev),
> + dai_link->cpu_name))
> continue;
> if (dai_link->cpu_dai_name &&
> - strcmp(cpu_dai->name, dai_link->cpu_dai_name))
> + !soc_match_name(cpu_dai->dev, cpu_dai->name,
> + dai_link->cpu_dai_name))
> continue;
>
> rtd->cpu_dai = cpu_dai;
> @@ -874,7 +898,8 @@ static int soc_bind_dai_link(struct snd_soc_card *card, int num)
> if (codec->dev->of_node != dai_link->codec_of_node)
> continue;
> } else {
> - if (strcmp(codec->name, dai_link->codec_name))
> + if (!soc_match_name(codec->dev, codec->name,
> + dai_link->codec_name))
> continue;
> }
>
> @@ -886,8 +911,8 @@ static int soc_bind_dai_link(struct snd_soc_card *card, int num)
> */
> list_for_each_entry(codec_dai, &dai_list, list) {
> if (codec->dev == codec_dai->dev &&
> - !strcmp(codec_dai->name,
> - dai_link->codec_dai_name)) {
> + soc_match_name(codec->dev, codec_dai->name,
> + dai_link->codec_dai_name)) {
>
> rtd->codec_dai = codec_dai;
> }
> @@ -918,7 +943,8 @@ static int soc_bind_dai_link(struct snd_soc_card *card, int num)
> dai_link->platform_of_node)
> continue;
> } else {
> - if (strcmp(platform->name, platform_name))
> + if (!soc_match_name(platform->dev, platform->name,
> + platform_name))
> continue;
> }
>
Thanks!
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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