[PATCH 3/3] ASoC: meson: aiu-encoder-i2s: use the core symmetric_rate handling

[Valerio Setti]

The driver manually implement the interface-wide rate symmetry enforcement
in hw_params(), which suffers from the same problem addressed in the
previous patch: the restriction is not visible in the hw parameter
constraints, so a stream with a mismatching rate only finds out via
-EINVAL late in the stream setup.

The ASoC core already provides this feature through the DAI's
'symmetric_rate' flag: when another stream of the DAI is active,
soc_pcm_apply_symmetry() constrains the rate at open time so the
restriction shows up during parameter refinement, and
soc_pcm_params_symmetry() still rejects a mismatch at hw_params()
time as a backstop.

Set 'symmetric_rate' on the I2S encoder DAI and drop the open-coded
check along with the now unused 'rate' member of struct gx_iface.

Signed-off-by: Valerio Setti <vsetti at baylibre.com>
---
 sound/soc/meson/aiu-encoder-i2s.c | 21 ++-------------------
 sound/soc/meson/aiu.c             |  1 +
 sound/soc/meson/gx-interface.h    |  3 ---
 3 files changed, 3 insertions(+), 22 deletions(-)

diff --git a/sound/soc/meson/aiu-encoder-i2s.c b/sound/soc/meson/aiu-encoder-i2s.c
index 4c62ea41d7e8..58dce9f08c9d 100644
--- a/sound/soc/meson/aiu-encoder-i2s.c
+++ b/sound/soc/meson/aiu-encoder-i2s.c
@@ -179,28 +179,14 @@ static int aiu_encoder_i2s_hw_params(struct snd_pcm_substream *substream,
 				     struct snd_soc_dai *dai)
 {
 	struct gx_stream *ts = snd_soc_dai_get_dma_data(dai, substream);
-	struct gx_iface *iface = ts->iface;
 	int ret;
 
-	/*
-	 * Enforce interface wide rate symmetry only if there is more than
-	 * 1 stream active.
-	 */
-	if (snd_soc_dai_active(dai) > 1) {
-		if (iface->rate && iface->rate != params_rate(params)) {
-			dev_err(dai->dev, "can't set iface rate (%d != %d)\n",
-				iface->rate, params_rate(params));
-			return -EINVAL;
-		}
-	}
-
 	ret = aiu_encoder_i2s_set_clocks(substream, params, dai);
 	if (ret) {
 		dev_err(dai->dev, "setting i2s clocks failed: %d\n", ret);
 		return ret;
 	}
 
-	iface->rate = params_rate(params);
 	ts->physical_width = params_physical_width(params);
 	ts->width = params_width(params);
 	ts->channels = params_channels(params);
@@ -233,17 +219,14 @@ static int aiu_encoder_i2s_hw_free(struct snd_pcm_substream *substream,
 				   struct snd_soc_dai *dai)
 {
 	struct gx_stream *ts = snd_soc_dai_get_dma_data(dai, substream);
-	struct gx_iface *iface = ts->iface;
 	struct snd_soc_component *component = dai->component;
 
 	/*
 	 * If this is the last substream being closed then disable the i2s
-	 * clock divider and clear 'iface->rate'.
+	 * clock divider.
 	 */
-	if (snd_soc_dai_active(dai) <= 1) {
+	if (snd_soc_dai_active(dai) <= 1)
 		aiu_encoder_i2s_divider_enable(component, 0);
-		iface->rate = 0;
-	}
 
 	if (ts->clk_enabled) {
 		clk_disable_unprepare(ts->iface->mclk);
diff --git a/sound/soc/meson/aiu.c b/sound/soc/meson/aiu.c
index 64ace4d25d92..2668646e3597 100644
--- a/sound/soc/meson/aiu.c
+++ b/sound/soc/meson/aiu.c
@@ -154,6 +154,7 @@ static struct snd_soc_dai_driver aiu_cpu_dai_drv[] = {
 			.formats = AIU_FORMATS,
 		},
 		.ops = &aiu_encoder_i2s_dai_ops,
+		.symmetric_rate = 1,
 	},
 	[CPU_SPDIF_ENCODER] = {
 		.name = "SPDIF Encoder",
diff --git a/sound/soc/meson/gx-interface.h b/sound/soc/meson/gx-interface.h
index d9ab894589fa..2a6207e393e8 100644
--- a/sound/soc/meson/gx-interface.h
+++ b/sound/soc/meson/gx-interface.h
@@ -19,9 +19,6 @@ struct gx_iface {
 
 	/* format is common to all the DAIs of the iface */
 	unsigned int fmt;
-
-	/* For component wide symmetry */
-	int rate;
 };
 
 struct gx_stream {

-- 
2.47.3