ASoC: arizona: Disable AIF TX/RX before configuring it

Changes to the AIF configuration registers only take
effect when the AIF is disabled. If the configuration
is being changed from the previous setup, temporarily
disable the AIF.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/arizona.c

@@ -1209,6 +1209,27 @@ static int arizona_hw_params_rate(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+static bool arizona_aif_cfg_changed(struct snd_soc_codec *codec,
+				    int base, int bclk, int lrclk, int frame)
+{
+	int val;
+
+	val = snd_soc_read(codec, base + ARIZONA_AIF_BCLK_CTRL);
+	if (bclk != (val & ARIZONA_AIF1_BCLK_FREQ_MASK))
+		return true;
+
+	val = snd_soc_read(codec, base + ARIZONA_AIF_TX_BCLK_RATE);
+	if (lrclk != (val & ARIZONA_AIF1TX_BCPF_MASK))
+		return true;
+
+	val = snd_soc_read(codec, base + ARIZONA_AIF_FRAME_CTRL_1);
+	if (frame != (val & (ARIZONA_AIF1TX_WL_MASK |
+			     ARIZONA_AIF1TX_SLOT_LEN_MASK)))
+		return true;
+
+	return false;
+}
+
 static int arizona_hw_params(struct snd_pcm_substream *substream,
 			     struct snd_pcm_hw_params *params,
 			     struct snd_soc_dai *dai)
@@ -1224,6 +1245,8 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
 	int tdm_width = arizona->tdm_width[dai->id - 1];
 	int tdm_slots = arizona->tdm_slots[dai->id - 1];
 	int bclk, lrclk, wl, frame, bclk_target;
+	bool reconfig;
+	unsigned int aif_tx_state, aif_rx_state;
 
 	if (params_rate(params) % 8000)
 		rates = &arizona_44k1_bclk_rates[0];
@@ -1274,28 +1297,56 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
 	wl = snd_pcm_format_width(params_format(params));
 	frame = wl << ARIZONA_AIF1TX_WL_SHIFT | wl;
 
+	reconfig = arizona_aif_cfg_changed(codec, base, bclk, lrclk, frame);
+
+	if (reconfig) {
+		/* Save AIF TX/RX state */
+		aif_tx_state = snd_soc_read(codec,
+					    base + ARIZONA_AIF_TX_ENABLES);
+		aif_rx_state = snd_soc_read(codec,
+					    base + ARIZONA_AIF_RX_ENABLES);
+		/* Disable AIF TX/RX before reconfiguring it */
+		regmap_update_bits_async(arizona->regmap,
+				    base + ARIZONA_AIF_TX_ENABLES, 0xff, 0x0);
+		regmap_update_bits(arizona->regmap,
+				    base + ARIZONA_AIF_RX_ENABLES, 0xff, 0x0);
+	}
+
 	ret = arizona_hw_params_rate(substream, params, dai);
 	if (ret != 0)
-		return ret;
+		goto restore_aif;
 
-	regmap_update_bits_async(arizona->regmap,
-				 base + ARIZONA_AIF_BCLK_CTRL,
-				 ARIZONA_AIF1_BCLK_FREQ_MASK, bclk);
-	regmap_update_bits_async(arizona->regmap,
-				 base + ARIZONA_AIF_TX_BCLK_RATE,
-				 ARIZONA_AIF1TX_BCPF_MASK, lrclk);
-	regmap_update_bits_async(arizona->regmap,
-				 base + ARIZONA_AIF_RX_BCLK_RATE,
-				 ARIZONA_AIF1RX_BCPF_MASK, lrclk);
-	regmap_update_bits_async(arizona->regmap,
-				 base + ARIZONA_AIF_FRAME_CTRL_1,
-				 ARIZONA_AIF1TX_WL_MASK |
-				 ARIZONA_AIF1TX_SLOT_LEN_MASK, frame);
-	regmap_update_bits(arizona->regmap, base + ARIZONA_AIF_FRAME_CTRL_2,
-			   ARIZONA_AIF1RX_WL_MASK |
-			   ARIZONA_AIF1RX_SLOT_LEN_MASK, frame);
+	if (reconfig) {
+		regmap_update_bits_async(arizona->regmap,
+					 base + ARIZONA_AIF_BCLK_CTRL,
+					 ARIZONA_AIF1_BCLK_FREQ_MASK, bclk);
+		regmap_update_bits_async(arizona->regmap,
+					 base + ARIZONA_AIF_TX_BCLK_RATE,
+					 ARIZONA_AIF1TX_BCPF_MASK, lrclk);
+		regmap_update_bits_async(arizona->regmap,
+					 base + ARIZONA_AIF_RX_BCLK_RATE,
+					 ARIZONA_AIF1RX_BCPF_MASK, lrclk);
+		regmap_update_bits_async(arizona->regmap,
+					 base + ARIZONA_AIF_FRAME_CTRL_1,
+					 ARIZONA_AIF1TX_WL_MASK |
+					 ARIZONA_AIF1TX_SLOT_LEN_MASK, frame);
+		regmap_update_bits(arizona->regmap,
+				   base + ARIZONA_AIF_FRAME_CTRL_2,
+				   ARIZONA_AIF1RX_WL_MASK |
+				   ARIZONA_AIF1RX_SLOT_LEN_MASK, frame);
+	}
 
-	return 0;
+restore_aif:
+	if (reconfig) {
+		/* Restore AIF TX/RX state */
+		regmap_update_bits_async(arizona->regmap,
+					 base + ARIZONA_AIF_TX_ENABLES,
+					 0xff, aif_tx_state);
+		regmap_update_bits(arizona->regmap,
+				   base + ARIZONA_AIF_RX_ENABLES,
+				   0xff, aif_rx_state);
+	}
+	return ret;
 }
 
 static const char *arizona_dai_clk_str(int clk_id)