[PATCH 2/3] ASoC: img-spdif-out: Add suspend / resume handling

[Ed Blake <ed.blake@sondrel.com>]

Implement ASoC suspend and resume callbacks to save and restore
register state, to support platforms where the power is disabled
during suspend.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
---
 sound/soc/img/img-spdif-out.c | 44 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/sound/soc/img/img-spdif-out.c b/sound/soc/img/img-spdif-out.c
index 416aa57..8123e2a 100644
--- a/sound/soc/img/img-spdif-out.c
+++ b/sound/soc/img/img-spdif-out.c
@@ -47,6 +47,9 @@ struct img_spdif_out {
 	struct snd_dmaengine_dai_dma_data dma_data;
 	struct device *dev;
 	struct reset_control *rst;
+	u32 suspend_ctl;
+	u32 suspend_csl;
+	u32 suspend_csh;
 };
 
 static int img_spdif_out_runtime_suspend(struct device *dev)
@@ -296,8 +299,49 @@ static int img_spdif_out_dai_probe(struct snd_soc_dai *dai)
 	return 0;
 }
 
+static int img_spdif_out_dai_suspend(struct snd_soc_dai *dai)
+{
+	struct img_spdif_out *spdif = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	if (pm_runtime_status_suspended(spdif->dev)) {
+		ret = img_spdif_out_runtime_resume(spdif->dev);
+		if (ret)
+			return ret;
+	}
+
+	spdif->suspend_ctl = img_spdif_out_readl(spdif, IMG_SPDIF_OUT_CTL);
+	spdif->suspend_csl = img_spdif_out_readl(spdif, IMG_SPDIF_OUT_CSL);
+	spdif->suspend_csh = img_spdif_out_readl(spdif, IMG_SPDIF_OUT_CSH_UV);
+
+	img_spdif_out_runtime_suspend(spdif->dev);
+
+	return 0;
+}
+
+static int img_spdif_out_dai_resume(struct snd_soc_dai *dai)
+{
+	struct img_spdif_out *spdif = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = img_spdif_out_runtime_resume(spdif->dev);
+	if (ret)
+		return ret;
+
+	img_spdif_out_writel(spdif, spdif->suspend_ctl, IMG_SPDIF_OUT_CTL);
+	img_spdif_out_writel(spdif, spdif->suspend_csl, IMG_SPDIF_OUT_CSL);
+	img_spdif_out_writel(spdif, spdif->suspend_csh, IMG_SPDIF_OUT_CSH_UV);
+
+	if (pm_runtime_status_suspended(spdif->dev))
+		img_spdif_out_runtime_suspend(spdif->dev);
+
+	return 0;
+}
+
 static struct snd_soc_dai_driver img_spdif_out_dai = {
 	.probe = img_spdif_out_dai_probe,
+	.suspend = img_spdif_out_dai_suspend,
+	.resume = img_spdif_out_dai_resume,
 	.playback = {
 		.channels_min = 2,
 		.channels_max = 2,
-- 
1.9.1