To create simple cards, the syntax of the simple-card does not follow the common binding of the device graphs (Documentation/devicetree/bindings/graph.txt).
dt-card devices are created by audio controllers with themselves as the root of the graph. The sound card is created according to the parameters found in the tree.
Signed-off-by: Jean-Francois Moine moinejf@free.fr --- sound/soc/generic/Kconfig | 2 + sound/soc/generic/Makefile | 2 + sound/soc/generic/dt-card.c | 275 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 279 insertions(+) create mode 100644 sound/soc/generic/dt-card.c
diff --git a/sound/soc/generic/Kconfig b/sound/soc/generic/Kconfig index 610f612..9c5e1e2 100644 --- a/sound/soc/generic/Kconfig +++ b/sound/soc/generic/Kconfig @@ -2,3 +2,5 @@ config SND_SIMPLE_CARD tristate "ASoC Simple sound card support" help This option enables generic simple sound card support +config SND_DT_CARD + tristate diff --git a/sound/soc/generic/Makefile b/sound/soc/generic/Makefile index 9c3b246..56834a9 100644 --- a/sound/soc/generic/Makefile +++ b/sound/soc/generic/Makefile @@ -1,3 +1,5 @@ snd-soc-simple-card-objs := simple-card.o +snd-soc-dt-card-objs := dt-card.o
obj-$(CONFIG_SND_SIMPLE_CARD) += snd-soc-simple-card.o +obj-$(CONFIG_SND_DT_CARD) += snd-soc-dt-card.o diff --git a/sound/soc/generic/dt-card.c b/sound/soc/generic/dt-card.c new file mode 100644 index 0000000..6a5de2f --- /dev/null +++ b/sound/soc/generic/dt-card.c @@ -0,0 +1,275 @@ +/* + * ALSA SoC DT based sound card support + * + * Copyright (C) 2015 Jean-Francois Moine + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <sound/soc.h> +#include <linux/of.h> +#include <linux/of_device.h> + +/* check if a node is an audio port */ +static int asoc_dt_card_is_audio_port(struct device_node *of_port) +{ + const char *name; + int ret; + + if (!of_port->name || + of_node_cmp(of_port->name, "port") != 0) + return 0; + ret = of_property_read_string(of_port, + "port-type", + &name); + if (!ret && + (strcmp(name, "i2s") == 0 || + strcmp(name, "spdif") == 0)) + return 1; + return 0; +} + +/* + * Get the DAI number from the DT by counting the audio ports + * of the remote device node (codec). + */ +static int asoc_dt_card_get_dai_number(struct device_node *of_codec, + struct device_node *of_remote_endpoint) +{ + struct device_node *of_port, *of_endpoint; + int ndai; + + ndai = 0; + for_each_child_of_node(of_codec, of_port) { + if (!asoc_dt_card_is_audio_port(of_port)) + continue; + for_each_child_of_node(of_port, of_endpoint) { + if (!of_endpoint->name || + of_node_cmp(of_endpoint->name, "endpoint") != 0) + continue; + if (of_endpoint == of_remote_endpoint) { + of_node_put(of_port); + of_node_put(of_endpoint); + return ndai; + } + } + ndai++; + } + return 0; /* should never be reached */ +} + +/* + * Parse a graph of audio ports + * @dev: Card device + * @of_cpu: Device node of the audio controller + * @card: Card definition + * + * Builds the DAI links of the card from the DT graph of audio ports + * starting from the audio controller. + * It does not handle the port groups. + * The CODEC device nodes in the DAI links must be dereferenced by the caller. + * + * Returns the number of DAI links or (< 0) on error + */ +static int asoc_dt_card_of_parse_graph(struct device *dev, + struct device_node *of_cpu, + struct snd_soc_card *card) +{ + struct device_node *of_codec, *of_port, *of_endpoint, + *of_remote_endpoint; + struct snd_soc_dai_link *link; + struct snd_soc_dai_link_component *component; + struct of_phandle_args args, args2; + int ret, ilink, icodec, nlinks, ncodecs; + + /* count the number of DAI links */ + nlinks = 0; + for_each_child_of_node(of_cpu, of_port) { + if (asoc_dt_card_is_audio_port(of_port)) + nlinks++; + } + + /* allocate the DAI link array */ + link = devm_kzalloc(dev, sizeof(*link) * nlinks, GFP_KERNEL); + if (!link) + return -ENOMEM; + card->dai_link = link; + + /* build the DAI links */ + ilink = 0; + args.np = of_cpu; + args.args_count = 1; + for_each_child_of_node(of_cpu, of_port) { + if (!asoc_dt_card_is_audio_port(of_port)) + continue; + + link->platform_of_node = + link->cpu_of_node = of_cpu; + args.args[0] = ilink; + ret = snd_soc_get_dai_name(&args, &link->cpu_dai_name); + if (ret) { + dev_err(dev, "no CPU DAI name for link %d!\n", + ilink); + continue; + } + + /* count the number of codecs of this DAI link */ + ncodecs = 0; + for_each_child_of_node(of_port, of_endpoint) { + if (of_parse_phandle(of_endpoint, + "remote-endpoint", 0)) + ncodecs++; + } + if (ncodecs == 0) + continue; + component = devm_kzalloc(dev, + sizeof(*component) * ncodecs, + GFP_KERNEL); + if (!component) + return -ENOMEM; + link->codecs = component; + + icodec = 0; + args2.args_count = 1; + for_each_child_of_node(of_port, of_endpoint) { + of_remote_endpoint = of_parse_phandle(of_endpoint, + "remote-endpoint", 0); + if (!of_remote_endpoint) + continue; + component->of_node = of_codec = + of_remote_endpoint->parent->parent; + args2.np = of_codec; + args2.args[0] = asoc_dt_card_get_dai_number(of_codec, + of_remote_endpoint); + ret = snd_soc_get_dai_name(&args2, + &component->dai_name); + if (ret) { + if (ret == -EPROBE_DEFER) { + card->num_links = ilink + 1; + link->num_codecs = icodec; + return ret; + } + dev_err(dev, + "no CODEC DAI name for link %d\n", + ilink); + continue; + } + of_node_get(of_codec); + + icodec++; + if (icodec >= ncodecs) + break; + component++; + } + if (icodec == 0) + continue; + link->num_codecs = icodec; + + ilink++; + if (ilink >= nlinks) + break; + link++; + } + card->num_links = ilink; + + return ilink; +} + +static void asoc_dt_card_unref(struct platform_device *pdev) +{ + struct snd_soc_card *card = platform_get_drvdata(pdev); + struct snd_soc_dai_link *link; + int nlinks, ncodecs; + + if (card) { + for (nlinks = 0, link = card->dai_link; + nlinks < card->num_links; + nlinks++, link++) { + for (ncodecs = 0; + ncodecs < link->num_codecs; + ncodecs++) + of_node_put(card->dai_link->codecs[ncodecs].of_node); + } + } +} + +/* + * The platform data contains the pointer to the device node + * which starts the description of the graph of the audio ports, + * This device node is usually the audio controller. + */ +static int asoc_dt_card_probe(struct platform_device *pdev) +{ + struct device_node **p_np = pdev->dev.platform_data; + struct device_node *of_cpu = *p_np; + struct snd_soc_card *card; + struct snd_soc_dai_link *link; + char *name; + int ret, i; + + card = devm_kzalloc(&pdev->dev, sizeof(*card), GFP_KERNEL); + if (!card) + return -ENOMEM; + ret = asoc_dt_card_of_parse_graph(&pdev->dev, of_cpu, card); + if (ret < 0) + goto err; + + /* fill the remaining values of the card */ + card->owner = THIS_MODULE; + card->dev = &pdev->dev; + card->name = "DT-card"; + for (i = 0, link = card->dai_link; + i < card->num_links; + i++, link++) { + name = devm_kzalloc(&pdev->dev, + strlen(link->cpu_dai_name) + + strlen(link->codecs[0].dai_name) + + 2, + GFP_KERNEL); + if (!name) { + ret = -ENOMEM; + goto err; + } + sprintf(name, "%s-%s", link->cpu_dai_name, + link->codecs[0].dai_name); + link->name = link->stream_name = name; + } + + card->dai_link->dai_fmt = + snd_soc_of_parse_daifmt(of_cpu, "dt-audio-card,", + NULL, NULL) & + ~SND_SOC_DAIFMT_MASTER_MASK; + + ret = devm_snd_soc_register_card(&pdev->dev, card); + if (ret >= 0) + return ret; + +err: + asoc_dt_card_unref(pdev); + return ret; +} + +static int asoc_dt_card_remove(struct platform_device *pdev) +{ + asoc_dt_card_unref(pdev); + snd_soc_unregister_card(platform_get_drvdata(pdev)); + return 0; +} + +static struct platform_driver asoc_dt_card = { + .driver = { + .name = "asoc-dt-card", + }, + .probe = asoc_dt_card_probe, + .remove = asoc_dt_card_remove, +}; + +module_platform_driver(asoc_dt_card); + +MODULE_ALIAS("platform:asoc-dt-card"); +MODULE_DESCRIPTION("ASoC DT Sound Card"); +MODULE_AUTHOR("Jean-Francois Moine moinejf@free.fr"); +MODULE_LICENSE("GPL");