On 10/17/2013 11:01 AM, Xiubo Li wrote:
[...]

+static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params,
+		struct snd_soc_dai *cpu_dai)
+{
+	int ret;
+
+	ret = fsl_sai_hw_params_tr(substream, params, cpu_dai,
+				FSL_FMT_TRANSMITTER);
+	if (ret) {
+		dev_err(cpu_dai->dev,
+				"Cannot set sai transmitter hw params: %d\n",
+				ret);
+		return ret;
+	}
+
+	ret = fsl_sai_hw_params_tr(substream, params, cpu_dai,
+				FSL_FMT_RECEIVER);
+	if (ret) {
+		dev_err(cpu_dai->dev,
+				"Cannot set sai's receiver hw params: %d\n",
+				ret);
+		return ret;
+	}

Shouldn't, depending on the substream direction, either transmit or receiver
be configured, instead of always configuring both?

+
+	return 0;
+}
+
+static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
+		struct snd_soc_dai *dai)
+{
+	struct fsl_sai *sai = snd_soc_dai_get_drvdata(dai);
+	unsigned int tcsr, rcsr;
+
+	tcsr = readl(sai->base + SAI_TCSR);
+	rcsr = readl(sai->base + SAI_RCSR);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		rcsr |= SAI_CSR_TERE | SAI_CSR_FRDE;
+		tcsr |= SAI_CSR_TERE | SAI_CSR_FRDE;
+		writel(rcsr, sai->base + SAI_RCSR);
+		udelay(10);
+		writel(tcsr, sai->base + SAI_TCSR);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		tcsr &= ~(SAI_CSR_TERE | SAI_CSR_FRDE);
+		rcsr &= ~(SAI_CSR_TERE | SAI_CSR_FRDE);
+		writel(tcsr, sai->base + SAI_TCSR);
+		udelay(10);
+		writel(rcsr, sai->base + SAI_RCSR);
+		break;
+	default:
+		return -EINVAL;
+	}
+

Same here, shouldn't tx and rx be started independently depending on the
substream direction?

+	return 0;
+}
+
+static struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {

const

+	.set_sysclk	= fsl_sai_set_dai_sysclk,
+	.set_clkdiv	= fsl_sai_set_dai_clkdiv,
+	.set_fmt	= fsl_sai_set_dai_fmt,
+	.set_tdm_slot	= fsl_sai_set_dai_tdm_slot,
+	.hw_params	= fsl_sai_hw_params,
+	.trigger	= fsl_sai_trigger,
+};

[...]

+static const struct snd_soc_component_driver fsl_component = {
+	.name           = "fsl-sai",
+};
+
+static int fsl_sai_probe(struct platform_device *pdev)
+{

[...]

+
+	sai->dma_params_rx.addr = res->start + SAI_RDR;
+	sai->dma_params_rx.maxburst = 6;
+	index = of_property_match_string(np, "dma-names", "rx");
+	ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", index,
+				&dma_args);
+	if (ret)
+		return ret;
+	sai->dma_params_rx.slave_id = dma_args.args[1];
+
+	sai->dma_params_tx.addr = res->start + SAI_TDR;
+	sai->dma_params_tx.maxburst = 6;
+	index = of_property_match_string(np, "dma-names", "tx");
+	ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", index,
+				&dma_args);
+	if (ret)
+		return ret;
+	sai->dma_params_tx.slave_id = dma_args.args[1];

The driver should not have to manually parse the dma devicetree properties,
this is something that should be handled by the dma engine driver.

+
+	ret = snd_soc_register_component(&pdev->dev, &fsl_component,
+			&fsl_sai_dai, 1);
+	if (ret)
+		return ret;
+
+	ret = fsl_pcm_dma_init(pdev);
+	if (ret)
+		goto out;
+
+	platform_set_drvdata(pdev, sai);
+
+	return 0;
+
+out:
+	snd_soc_unregister_component(&pdev->dev);
+	return ret;
+}