Re: [alsa-devel] [PATCH v2 1/3] ALSA SoC: Add OpenFirmware helper for matching bus and codec drivers

On Sat, Jul 12, 2008 at 02:39:29AM -0600, Grant Likely wrote:

From: Grant Likely grant.likely@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.

---

[...]

--- /dev/null +++ b/sound/soc/soc-of.c

It's quite inconvenient to spread the firmware-specific bits over the whole kernel source tree. So, can we place this in driver/of/, just as we did for i2c, spi and gpio?

@@ -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@secretlab.ca"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ALSA SoC OpenFirmware bindings");

+static DEFINE_MUTEX(of_snd_soc_mutex); +static 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;

+}

+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);

Thanks,