From bec4fa05e25f7e78ec67df389539acc6bb352a2a Mon Sep 17 00:00:00 2001
From: Stephen Warren <swarren@nvidia.com>
Date: Mon, 12 Dec 2011 15:55:34 -0700
Subject: ASoC: Add utility to set a card's name from device tree

Implement snd_soc_of_parse_card_name(), a utility function that sets a
card's name from device tree. The machine driver specifies the DT
property to use, since this is binding-specific.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
 include/sound/soc.h  |  3 +++
 sound/soc/soc-core.c | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index a35cf14a8eb..278f3b892ca 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -961,6 +961,9 @@ static inline bool snd_soc_volsw_is_stereo(struct soc_mixer_control *mc)
 int snd_soc_util_init(void);
 void snd_soc_util_exit(void);
 
+int snd_soc_of_parse_card_name(struct snd_soc_card *card,
+			       const char *propname);
+
 #include <sound/soc-dai.h>
 
 #ifdef CONFIG_DEBUG_FS
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 1252ab1ebf6..51eef9b7b53 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -32,6 +32,7 @@
 #include <linux/platform_device.h>
 #include <linux/ctype.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 #include <sound/ac97_codec.h>
 #include <sound/core.h>
 #include <sound/jack.h>
@@ -3317,6 +3318,30 @@ found:
 }
 EXPORT_SYMBOL_GPL(snd_soc_unregister_codec);
 
+/* Retrieve a card's name from device tree */
+int snd_soc_of_parse_card_name(struct snd_soc_card *card,
+			       const char *propname)
+{
+	struct device_node *np = card->dev->of_node;
+	int ret;
+
+	ret = of_property_read_string_index(np, propname, 0, &card->name);
+	/*
+	 * EINVAL means the property does not exist. This is fine providing
+	 * card->name was previously set, which is checked later in
+	 * snd_soc_register_card.
+	 */
+	if (ret < 0 && ret != -EINVAL) {
+		dev_err(card->dev,
+			"Property '%s' could not be read: %d\n",
+			propname, ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_of_parse_card_name);
+
 static int __init snd_soc_init(void)
 {
 #ifdef CONFIG_DEBUG_FS
-- 
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