[alsa-devel] [PATCH 3/6] ASoC: davinci-mcasp: Simplify and clean up the AFIFO configuration code

1 Apr 2014

We can have more linear code flow by using variables in
mcasp_common_hw_param() related to the AFIFO configuration.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com
---
 sound/soc/davinci/davinci-mcasp.c | 48 +++++++++++++++++++--------------------
 sound/soc/davinci/davinci-mcasp.h |  1 +
 2 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index 4007b1f3141b..9620d0165133 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -38,6 +38,8 @@
 #include "davinci-pcm.h"
 #include "davinci-mcasp.h"
+#define MCASP_MAX_AFIFO_DEPTH	64
+
 struct davinci_mcasp_context {
    u32	txfmtctl;
    u32	rxfmtctl;
@@ -461,9 +463,9 @@ static int mcasp_common_hw_param(struct davinci_mcasp *mcasp, int stream,
    int i;
    u8 tx_ser = 0;
    u8 rx_ser = 0;
-	u8 ser;
    u8 slots = mcasp->tdm_slots;
    u8 max_active_serializers = (channels + slots - 1) / slots;
+	u8 active_serializers, numevt;
    u32 reg;
    /* Default configuration */
    if (mcasp->version != MCASP_VERSION_4)
@@ -497,36 +499,34 @@ static int mcasp_common_hw_param(struct davinci_mcasp *mcasp, int stream,
    	}
    }
-	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
-		ser = tx_ser;
-	else
-		ser = rx_ser;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		active_serializers = tx_ser;
+		numevt = mcasp->txnumevt;
+		reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;
+	} else {
+		active_serializers = rx_ser;
+		numevt = mcasp->rxnumevt;
+		reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;
+	}
-	if (ser < max_active_serializers) {
+	if (active_serializers < max_active_serializers) {
    	dev_warn(mcasp->dev, "stream has more channels (%d) than are "
-			"enabled in mcasp (%d)\n", channels, ser * slots);
+			 "enabled in mcasp (%d)\n", channels,
+			 active_serializers * slots);
    	return -EINVAL;
    }
-	if (mcasp->txnumevt && stream == SNDRV_PCM_STREAM_PLAYBACK) {
-		if (mcasp->txnumevt * tx_ser > 64)
-			mcasp->txnumevt = 1;
-
-		reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;
-		mcasp_mod_bits(mcasp, reg, tx_ser, NUMDMA_MASK);
-		mcasp_mod_bits(mcasp, reg, ((mcasp->txnumevt * tx_ser) << 8),
-			       NUMEVT_MASK);
-	}
+	/* AFIFO is not in use */
+	if (!numevt)
+		return 0;
-	if (mcasp->rxnumevt && stream == SNDRV_PCM_STREAM_CAPTURE) {
-		if (mcasp->rxnumevt * rx_ser > 64)
-			mcasp->rxnumevt = 1;
+	if (numevt * active_serializers > MCASP_MAX_AFIFO_DEPTH)
+		numevt = active_serializers;
-		reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;
-		mcasp_mod_bits(mcasp, reg, rx_ser, NUMDMA_MASK);
-		mcasp_mod_bits(mcasp, reg, ((mcasp->rxnumevt * rx_ser) << 8),
-			       NUMEVT_MASK);
-	}
+	/* Configure the AFIFO */
+	numevt *= active_serializers;
+	mcasp_mod_bits(mcasp, reg, active_serializers, NUMDMA_MASK);
+	mcasp_mod_bits(mcasp, reg, NUMEVT(numevt), NUMEVT_MASK);
return 0;
 }
diff --git a/sound/soc/davinci/davinci-mcasp.h b/sound/soc/davinci/davinci-mcasp.h
index 53243c22818d..9737108f0305 100644
--- a/sound/soc/davinci/davinci-mcasp.h
+++ b/sound/soc/davinci/davinci-mcasp.h
@@ -289,6 +289,7 @@
  */
 #define FIFO_ENABLE	BIT(16)
 #define NUMEVT_MASK	(0xFF << 8)
+#define NUMEVT(x)	(((x) & 0xFF) << 8)
 #define NUMDMA_MASK	(0xFF)
#endif	/* DAVINCI_MCASP_H */
-- 
1.9.1


    