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, 10 insertions, 2 deletions

diff --git a/sound/soc/tegra/tegra20_ac97.c b/sound/soc/tegra/tegra20_ac97.c
index 48037f784a86..f52eab6d2231 100644
--- a/sound/soc/tegra/tegra20_ac97.c
+++ b/sound/soc/tegra/tegra20_ac97.c
@@ -142,13 +142,12 @@ static void tegra20_ac97_codec_write(struct snd_ac97 *ac97_snd,
         } while (!time_after(jiffies, timeout));
 }
 
-struct snd_ac97_bus_ops soc_ac97_ops = {
+static struct snd_ac97_bus_ops tegra20_ac97_ops = {
         .read           = tegra20_ac97_codec_read,
         .write          = tegra20_ac97_codec_write,
         .reset          = tegra20_ac97_codec_reset,
         .warm_reset     = tegra20_ac97_codec_warm_reset,
 };
-EXPORT_SYMBOL_GPL(soc_ac97_ops);
 
 static inline void tegra20_ac97_start_playback(struct tegra20_ac97 *ac97)
 {
@@ -409,6 +408,12 @@ static int tegra20_ac97_platform_probe(struct platform_device *pdev)
                 goto err_asoc_utils_fini;
         }
 
+        ret = snd_soc_set_ac97_ops(&tegra20_ac97_ops);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to set AC'97 ops: %d\n", ret);
+                goto err_asoc_utils_fini;
+        }
+
         ret = snd_soc_register_component(&pdev->dev, &tegra20_ac97_component,
                                          &tegra20_ac97_dai, 1);
         if (ret) {
@@ -436,6 +441,7 @@ err_asoc_utils_fini:
         tegra_asoc_utils_fini(&ac97->util_data);
 err_clk_put:
 err:
+        snd_soc_set_ac97_ops(NULL);
         return ret;
 }
 
@@ -450,6 +456,8 @@ static int tegra20_ac97_platform_remove(struct platform_device *pdev)
 
         clk_disable_unprepare(ac97->clk_ac97);
 
+        snd_soc_set_ac97_ops(NULL);
+
         return 0;
 }