[PATCH v2 2/6] ASoC: renesas: fsi: Fix hang by enabling SPU clock

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

Enable/disable the shared SPU clock in hw startup/shutdown. Without this,
accessing FSI registers may hang the system.

Suggested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---

Changes in v2:
 - Move SPU clock enable/disable handling from fsi_dai_startup/shutdown 
   to fsi_hw_startup/shutdown

 sound/soc/renesas/fsi.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/sound/soc/renesas/fsi.c b/sound/soc/renesas/fsi.c
index 196ec7bac33d..109e06b5f32d 100644
--- a/sound/soc/renesas/fsi.c
+++ b/sound/soc/renesas/fsi.c
@@ -1492,6 +1492,18 @@ static int fsi_hw_startup(struct fsi_priv *fsi,
 			  struct device *dev)
 {
 	u32 data = 0;
+	int ret = 0;
+	/* enable spu clock */
+	mutex_lock(&fsi->master->clk_lock);
+	if (fsi->master->clk_spu && fsi->master->spu_count++ == 0) {
+		ret = clk_prepare_enable(fsi->master->clk_spu);
+		if (ret < 0) {
+			fsi->master->spu_count--;
+			mutex_unlock(&fsi->master->clk_lock);
+			return ret;
+		}
+	}
+	mutex_unlock(&fsi->master->clk_lock);
 
 	/* clock setting */
 	if (fsi_is_clk_master(fsi))
@@ -1549,6 +1561,11 @@ static int fsi_hw_shutdown(struct fsi_priv *fsi,
 	/* stop master clock */
 	if (fsi_is_clk_master(fsi))
 		return fsi_clk_disable(dev, fsi);
+	/* stop spu clock */
+	mutex_lock(&fsi->master->clk_lock);
+	if (fsi->master->clk_spu && --fsi->master->spu_count == 0)
+		clk_disable_unprepare(fsi->master->clk_spu);
+	mutex_unlock(&fsi->master->clk_lock);
 
 	return 0;
 }
-- 
2.43.0