[alsa-devel] [PATCH 3/3] ASoC: rsnd: SSI parent cares SWSP bit

[Kuninori Morimoto]

From: Kuninori Morimoto <kuninori.morimoto.gx at renesas.com>

SSICR has SWSP bit (= Serial WS Polarity) which decides WS pin 1st
channel polarity (low or hi). This bit shouldn't exchange after running.

Current SSI "parent" doesn't care SSICR, just controls clock only.
Because of this behavior, if platform uses SSI0 as playback,
SSI1 as capture, and if user starts capture -> playback order,
SSI0 SSICR::SWSP bit exchanged 0 -> 1 during captureing, and it makes
capture noise.
This patch cares SSICR on SSI parent, too.
Special thanks to Yokoyama-san

Reported-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx at renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx at renesas.com>
Tested-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx at renesas.com>
---
 sound/soc/sh/rcar/ssi.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c
index 4e60564..98dd120 100644
--- a/sound/soc/sh/rcar/ssi.c
+++ b/sound/soc/sh/rcar/ssi.c
@@ -37,6 +37,7 @@
 #define	CHNL_4		(1 << 22)	/* Channels */
 #define	CHNL_6		(2 << 22)	/* Channels */
 #define	CHNL_8		(3 << 22)	/* Channels */
+#define DWL_MASK	(7 << 19)	/* Data Word Length mask */
 #define	DWL_8		(0 << 19)	/* Data Word Length */
 #define	DWL_16		(1 << 19)	/* Data Word Length */
 #define	DWL_18		(2 << 19)	/* Data Word Length */
@@ -353,21 +354,18 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 	struct rsnd_dai *rdai = rsnd_io_to_rdai(io);
 	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
 	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
-	u32 cr_own;
-	u32 cr_mode;
-	u32 wsr;
+	u32 cr_own	= ssi->cr_own;
+	u32 cr_mode	= ssi->cr_mode;
+	u32 wsr		= ssi->wsr;
 	int is_tdm;
 
-	if (rsnd_ssi_is_parent(mod, io))
-		return;
-
 	is_tdm = rsnd_runtime_is_ssi_tdm(io);
 
 	/*
 	 * always use 32bit system word.
 	 * see also rsnd_ssi_master_clk_enable()
 	 */
-	cr_own = FORCE | SWL_32;
+	cr_own |= FORCE | SWL_32;
 
 	if (rdai->bit_clk_inv)
 		cr_own |= SCKP;
@@ -377,9 +375,18 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 		cr_own |= SDTA;
 	if (rdai->sys_delay)
 		cr_own |= DEL;
+
+	/*
+	 * We shouldn't exchange SWSP after running.
+	 * This means, parent needs to care it.
+	 */
+	if (rsnd_ssi_is_parent(mod, io))
+		goto init_end;
+
 	if (rsnd_io_is_play(io))
 		cr_own |= TRMD;
 
+	cr_own &= ~DWL_MASK;
 	switch (snd_pcm_format_width(runtime->format)) {
 	case 16:
 		cr_own |= DWL_16;
@@ -406,7 +413,7 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 		wsr	|= WS_MODE;
 		cr_own	|= CHNL_8;
 	}
-
+init_end:
 	ssi->cr_own	= cr_own;
 	ssi->cr_mode	= cr_mode;
 	ssi->wsr	= wsr;
@@ -470,15 +477,18 @@ static int rsnd_ssi_quit(struct rsnd_mod *mod,
 		return -EIO;
 	}
 
-	if (!rsnd_ssi_is_parent(mod, io))
-		ssi->cr_own	= 0;
-
 	rsnd_ssi_master_clk_stop(mod, io);
 
 	rsnd_mod_power_off(mod);
 
 	ssi->usrcnt--;
 
+	if (!ssi->usrcnt) {
+		ssi->cr_own	= 0;
+		ssi->cr_mode	= 0;
+		ssi->wsr	= 0;
+	}
+
 	return 0;
 }
 
-- 
1.9.1