[alsa-devel] [PATCH 1/3] ALSA SoC: Add OpenFirmware helper for matching bus and codec drivers
Jon Smirl
jonsmirl at gmail.com
Wed Jul 2 17:27:17 CEST 2008
On 7/1/08, Grant Likely <grant.likely at secretlab.ca> wrote:
> From: Grant Likely <grant.likely at secretlab.ca>
>
> Simple utility layer for creating ASoC machine instances based on data
> in the OpenFirmware device tree. OF aware platform drivers and codec
> drivers register themselves with this framework and the framework
> automatically instantiates a machine driver.
>
> This is most likely temporary glue code to work around limitations in
> the ASoC v1 framework. I expect ASoC v2 won't need this.
> ---
>
> sound/soc/Kconfig | 6 ++
> sound/soc/Makefile | 1
> sound/soc/soc-of.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 178 insertions(+), 0 deletions(-)
>
> diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
> index 18f28ac..c5736e5 100644
> --- a/sound/soc/Kconfig
> +++ b/sound/soc/Kconfig
> @@ -23,6 +23,12 @@ config SND_SOC
> This ASoC audio support can also be built as a module. If so, the module
> will be called snd-soc-core.
>
> +config SND_SOC_OF
> + tristate "OF helpers for SoC audio support"
> + depends on SND_SOC
> + ---help---
> + Add support for OpenFirmware device tree descriptions of sound device
> +
> # All the supported Soc's
> source "sound/soc/at91/Kconfig"
> source "sound/soc/pxa/Kconfig"
> diff --git a/sound/soc/Makefile b/sound/soc/Makefile
> index 782db21..191c2e5 100644
> --- a/sound/soc/Makefile
> +++ b/sound/soc/Makefile
> @@ -2,3 +2,4 @@ snd-soc-core-objs := soc-core.o soc-dapm.o
>
> obj-$(CONFIG_SND_SOC) += snd-soc-core.o
> obj-$(CONFIG_SND_SOC) += codecs/ at91/ pxa/ s3c24xx/ sh/ fsl/ davinci/ omap/
> +obj-$(CONFIG_SND_SOC_OF) += soc-of.o
> diff --git a/sound/soc/soc-of.c b/sound/soc/soc-of.c
> new file mode 100644
> index 0000000..9694979
> --- /dev/null
> +++ b/sound/soc/soc-of.c
> @@ -0,0 +1,171 @@
> +/*
> + * OF helpers for ALSA SoC Layer
> + *
> + * Copyright (C) 2008, Secret Lab Technologies Ltd.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/init.h>
> +#include <linux/delay.h>
> +#include <linux/pm.h>
> +#include <linux/bitops.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <sound/core.h>
> +#include <sound/pcm.h>
> +#include <sound/pcm_params.h>
> +#include <sound/soc.h>
> +#include <sound/soc-of.h>
> +#include <sound/initval.h>
> +
> +MODULE_AUTHOR("Grant Likely <grant.likely at secretlab.ca>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("ALSA SoC OpenFirmware bindings");
> +
> +DEFINE_MUTEX(of_snd_soc_mutex);
> +LIST_HEAD(of_snd_soc_device_list);
> +static int of_snd_soc_next_index;
> +
> +struct of_snd_soc_device {
> + int id;
> + struct list_head list;
> + struct snd_soc_device device;
> + struct snd_soc_machine machine;
> + struct snd_soc_dai_link dai_link;
> + struct platform_device *pdev;
> + struct device_node *platform_node;
> + struct device_node *codec_node;
> +};
> +
> +static struct snd_soc_ops of_snd_soc_ops = {
> +};
> +
> +static struct of_snd_soc_device *
> +of_snd_soc_get_device(struct device_node *codec_node)
> +{
> + struct of_snd_soc_device *of_soc;
> +
> + list_for_each_entry(of_soc, &of_snd_soc_device_list, list) {
> + if (of_soc->codec_node == codec_node)
> + return of_soc;
> + }
> +
> + of_soc = kzalloc(sizeof(struct of_snd_soc_device), GFP_KERNEL);
> + if (!of_soc)
> + return NULL;
> +
> + /* Initialize the structure and add it to the global list */
> + of_soc->codec_node = codec_node;
> + of_soc->id = of_snd_soc_next_index++;
> + of_soc->machine.dai_link = &of_soc->dai_link;
> + of_soc->machine.num_links = 1;
> + of_soc->device.machine = &of_soc->machine;
> + of_soc->dai_link.ops = &of_snd_soc_ops;
> + list_add(&of_soc->list, &of_snd_soc_device_list);
> +
> + return of_soc;
> +}
Isn't this performing the same basic function as this code (except for
spi)? Should this list be maintained in alsa or should there be an
equivalent for searching the spi bus? If you follow the link to the
codec node and get it's parent you know which bus to search. But it
might be simpler to just search the buses sequentially for the node.
static int of_dev_node_match(struct device *dev, void *data)
{
return dev->archdata.of_node == data;
}
struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
{
struct device *dev;
dev = bus_find_device(&i2c_bus_type, NULL, node,
of_dev_node_match);
if (!dev)
return NULL;
return to_i2c_client(dev);
}
EXPORT_SYMBOL(of_find_i2c_device_by_node);
> +
> +static void of_snd_soc_register_device(struct of_snd_soc_device *of_soc)
> +{
> + struct platform_device *pdev;
> + int rc;
> +
> + /* Only register the device if both the codec and platform have
> + * been registered */
> + if ((!of_soc->device.codec_data) || (!of_soc->platform_node))
> + return;
> +
> + pr_info("platform<-->codec match achieved; registering machine\n");
> +
> + pdev = platform_device_alloc("soc-audio", of_soc->id);
> + if (!pdev) {
> + pr_err("of_soc: platform_device_alloc() failed\n");
> + return;
> + }
> +
> + pdev->dev.platform_data = of_soc;
> + platform_set_drvdata(pdev, &of_soc->device);
> + of_soc->device.dev = &pdev->dev;
> +
> + /* The ASoC device is complete; register it */
> + rc = platform_device_add(pdev);
> + if (rc) {
> + pr_err("of_soc: platform_device_add() failed\n");
> + return;
> + }
> +
> +}
> +
> +int of_snd_soc_register_codec(struct snd_soc_codec_device *codec_dev,
> + void *codec_data, struct snd_soc_codec_dai *dai,
> + struct device_node *node)
> +{
> + struct of_snd_soc_device *of_soc;
> + int rc = 0;
> +
> + pr_info("registering ASoC codec driver: %s\n", node->full_name);
> +
> + mutex_lock(&of_snd_soc_mutex);
> + of_soc = of_snd_soc_get_device(node);
> + if (!of_soc) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + /* Store the codec data */
> + of_soc->device.codec_data = codec_data;
> + of_soc->device.codec_dev = codec_dev;
> + of_soc->dai_link.name = node->name;
> + of_soc->dai_link.stream_name = node->name;
> + of_soc->dai_link.codec_dai = dai;
> +
> + /* Now try to register the SoC device */
> + of_snd_soc_register_device(of_soc);
> +
> + out:
> + mutex_unlock(&of_snd_soc_mutex);
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(of_snd_soc_register_codec);
> +
> +int of_snd_soc_register_platform(struct snd_soc_platform *platform,
> + struct device_node *node,
> + struct snd_soc_cpu_dai *cpu_dai)
> +{
> + struct of_snd_soc_device *of_soc;
> + struct device_node *codec_node;
> + const phandle *handle;
> + int len, rc = 0;
> +
> + pr_info("registering ASoC platform driver: %s\n", node->full_name);
> +
> + handle = of_get_property(node, "codec-handle", &len);
> + if (!handle || len < sizeof(handle))
> + return -ENODEV;
> + codec_node = of_find_node_by_phandle(*handle);
> + if (!codec_node)
> + return -ENODEV;
> + pr_info("looking for codec: %s\n", codec_node->full_name);
> +
> + mutex_lock(&of_snd_soc_mutex);
> + of_soc = of_snd_soc_get_device(codec_node);
> + if (!of_soc) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + of_soc->platform_node = node;
> + of_soc->dai_link.cpu_dai = cpu_dai;
> + of_soc->device.platform = platform;
> + of_soc->machine.name = of_soc->dai_link.cpu_dai->name;
> +
> + /* Now try to register the SoC device */
> + of_snd_soc_register_device(of_soc);
> +
> + out:
> + mutex_unlock(&of_snd_soc_mutex);
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(of_snd_soc_register_platform);
>
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel at alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>
--
Jon Smirl
jonsmirl at gmail.com
More information about the Alsa-devel
mailing list