ASoC: stm32: i2s: manage rebind issue

The commit e894efef ("ASoC: core: add support to card rebind")
allows to rebind the sound card after a rebind of one of its component.
With this commit, the sound card is actually rebound,
but may be no more functional.

Corrections:
- Call snd_dmaengine_pcm_register() before snd_soc_register_component().
- Call snd_dmaengine_pcm_unregister() and snd_soc_unregister_component()
explicitly from I2S driver.
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Link: https://lore.kernel.org/r/20200318144125.9163-4-olivier.moysan@st.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/stm/stm32_i2s.c

@@ -888,6 +888,14 @@ static int stm32_i2s_parse_dt(struct platform_device *pdev,
 	return 0;
 }
 
+static int stm32_i2s_remove(struct platform_device *pdev)
+{
+	snd_dmaengine_pcm_unregister(&pdev->dev);
+	snd_soc_unregister_component(&pdev->dev);
+
+	return 0;
+}
+
 static int stm32_i2s_probe(struct platform_device *pdev)
 {
 	struct stm32_i2s_data *i2s;
@@ -921,47 +929,56 @@ static int stm32_i2s_probe(struct platform_device *pdev)
 		return PTR_ERR(i2s->regmap);
 	}
 
-	ret = devm_snd_soc_register_component(&pdev->dev, &stm32_i2s_component,
-					      i2s->dai_drv, 1);
-	if (ret)
-		return ret;
-
-	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
-					      &stm32_i2s_pcm_config, 0);
+	ret = snd_dmaengine_pcm_register(&pdev->dev, &stm32_i2s_pcm_config, 0);
 	if (ret) {
 		if (ret != -EPROBE_DEFER)
 			dev_err(&pdev->dev, "PCM DMA register error %d\n", ret);
 		return ret;
 	}
 
+	ret = snd_soc_register_component(&pdev->dev, &stm32_i2s_component,
+					 i2s->dai_drv, 1);
+	if (ret) {
+		snd_dmaengine_pcm_unregister(&pdev->dev);
+		return ret;
+	}
+
 	/* Set SPI/I2S in i2s mode */
 	ret = regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,
 				 I2S_CGFR_I2SMOD, I2S_CGFR_I2SMOD);
 	if (ret)
-		return ret;
+		goto error;
 
 	ret = regmap_read(i2s->regmap, STM32_I2S_IPIDR_REG, &val);
 	if (ret)
-		return ret;
+		goto error;
 
 	if (val == I2S_IPIDR_NUMBER) {
 		ret = regmap_read(i2s->regmap, STM32_I2S_HWCFGR_REG, &val);
 		if (ret)
-			return ret;
+			goto error;
 
 		if (!FIELD_GET(I2S_HWCFGR_I2S_SUPPORT_MASK, val)) {
 			dev_err(&pdev->dev,
 				"Device does not support i2s mode\n");
-			return -EPERM;
+			ret = -EPERM;
+			goto error;
 		}
 
 		ret = regmap_read(i2s->regmap, STM32_I2S_VERR_REG, &val);
+		if (ret)
+			goto error;
 
 		dev_dbg(&pdev->dev, "I2S version: %lu.%lu registered\n",
 			FIELD_GET(I2S_VERR_MAJ_MASK, val),
 			FIELD_GET(I2S_VERR_MIN_MASK, val));
 	}
 
+	return ret;
+
+error:
+	stm32_i2s_remove(pdev);
+
 	return ret;
 }
 
@@ -998,6 +1015,7 @@ static struct platform_driver stm32_i2s_driver = {
 		.pm = &stm32_i2s_pm_ops,
 	},
 	.probe = stm32_i2s_probe,
+	.remove = stm32_i2s_remove,
 };
 
 module_platform_driver(stm32_i2s_driver);