ASoC: ac97: Support multi-platform AC'97

Currently we can only have a single platform built in with AC'97 support
due to the use of a global variable to provide the bus operations. Fix
this by making that variable a pointer and having the bus drivers set the
operations prior to registering.

This is not a particularly good or nice approach but it avoids blocking
multiplatform and a real fix involves fixing the fairly deep problems
with AC'97 support - we should be converting it to a real bus.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/sound/soc/nuc900/nuc900-ac97.c b/sound/soc/nuc900/nuc900-ac97.c
index 8dea4c1fd997..f4c2417a8730 100644
--- a/sound/soc/nuc900/nuc900-ac97.c
+++ b/sound/soc/nuc900/nuc900-ac97.c
@@ -197,13 +197,12 @@ static void nuc900_ac97_cold_reset(struct snd_ac97 *ac97)
 }
 
 /* AC97 controller operations */
-struct snd_ac97_bus_ops soc_ac97_ops = {
+static struct snd_ac97_bus_ops nuc900_ac97_ops = {
         .read           = nuc900_ac97_read,
         .write          = nuc900_ac97_write,
         .reset          = nuc900_ac97_cold_reset,
         .warm_reset     = nuc900_ac97_warm_reset,
-}
-EXPORT_SYMBOL_GPL(soc_ac97_ops);
+};
 
 static int nuc900_ac97_trigger(struct snd_pcm_substream *substream,
                                 int cmd, struct snd_soc_dai *dai)
@@ -356,6 +355,10 @@ static int nuc900_ac97_drvprobe(struct platform_device *pdev)
 
         nuc900_ac97_data = nuc900_audio;
 
+        ret = snd_soc_set_ac97_ops(&nuc900_ac97_ops);
+        if (ret)
+                goto out;
+
         ret = snd_soc_register_component(&pdev->dev, &nuc900_ac97_component,
                                          &nuc900_ac97_dai, 1);
         if (ret)
@@ -367,6 +370,7 @@ static int nuc900_ac97_drvprobe(struct platform_device *pdev)
         return 0;
 
 out:
+        snd_soc_set_ac97_ops(NULL);
         return ret;
 }
 
@@ -375,6 +379,7 @@ static int nuc900_ac97_drvremove(struct platform_device *pdev)
         snd_soc_unregister_component(&pdev->dev);
 
         nuc900_ac97_data = NULL;
+        snd_soc_set_ac97_ops(NULL);
 
         return 0;
 }