ASoC: Add DAI list to debugfs

Allow the user to inspect the list of registered DAIs at runtime to
improve diagnostics for machine driver setup.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 29 insertions, 0 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 94a2edf9cfd5..63d93b3b7b7a 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -297,6 +297,32 @@ static const struct file_operations codec_list_fops = {
         .llseek = default_llseek,/* read accesses f_pos */
 };
 
+static ssize_t dai_list_read_file(struct file *file, char __user *user_buf,
+                                  size_t count, loff_t *ppos)
+{
+        char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+        ssize_t ret = 0;
+        struct snd_soc_dai *dai;
+
+        if (!buf)
+                return -ENOMEM;
+
+        list_for_each_entry(dai, &dai_list, list)
+                ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n", dai->name);
+
+        if (ret >= 0)
+                ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+
+        kfree(buf);
+
+        return ret;
+}
+
+static const struct file_operations dai_list_fops = {
+        .read = dai_list_read_file,
+        .llseek = default_llseek,/* read accesses f_pos */
+};
+
 #else
 
 static inline void soc_init_codec_debugfs(struct snd_soc_codec *codec)
@@ -3223,6 +3249,9 @@ static int __init snd_soc_init(void)
                                  &codec_list_fops))
                 pr_warn("ASoC: Failed to create CODEC list debugfs file\n");
 
+        if (!debugfs_create_file("dais", 0444, debugfs_root, NULL,
+                                 &dai_list_fops))
+                pr_warn("ASoC: Failed to create DAI list debugfs file\n");
 #endif
 
         return platform_driver_register(&soc_driver);