Add SPDIF support for Allwinner SoCs

From: Marcus Cooper <[email protected]>

Add devicetree bindings for the SPDIF transceiver found on found on Allwinners A10 and A20 SoCs.

Signed-off-by Marcus Cooper <[email protected]>

---
 .../devicetree/bindings/sound/sun4i,spdif.txt      | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/sun4i,spdif.txt

Documentation/devicetree/bindings/sound/sun4i,spdif.txt new file +21 -0

new file mode 100644
index 0000000..55ed2f6
@@ -0,0 +1,46 @@
+Allwinner Sony/Philips Digital Interface Format (S/PDIF) Controller
+
+The Allwinner S/PDIF audio block is a transceiver that allows the
+processor to receive and transmit digital audio via an coaxial cable or
+a fibre cable.
+
+Required properties:
+
+  - compatible		: should be one of the following:
+    - "allwinner,sun4i-a10-spdif": for the Allwinner A10 SoC
+
+  - reg			: Offset and length of the register set for the device.
+
+  - interrupts		: Contains the spdif interrupt.
+
+  - dmas		: Generic dma devicetree binding as described in
+			  Documentation/devicetree/bindings/dma/dma.txt.
+
+  - dma-names		: Two dmas have to be defined, "tx" and "rx".
+
+  - clocks		: Contains an entry for each entry in clock-names.

Hi,

Quoted 42 lines · On Tue, Feb 02, 2016 at 03:49:53PM +0100…

From: Marcus Cooper <[email protected]>

Add devicetree bindings for the SPDIF transceiver found on found on Allwinners A10 and A20 SoCs.

Signed-off-by Marcus Cooper <[email protected]>

---
 .../devicetree/bindings/sound/sun4i,spdif.txt      | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/sun4i,spdif.txt

Documentation/devicetree/bindings/sound/sun4i,spdif.txt new file +25 -0

new file mode 100644
index 0000000..55ed2f6
@@ -0,0 +1,46 @@
+Allwinner Sony/Philips Digital Interface Format (S/PDIF) Controller
+
+The Allwinner S/PDIF audio block is a transceiver that allows the
+processor to receive and transmit digital audio via an coaxial cable or
+a fibre cable.
+
+Required properties:
+
+  - compatible               : should be one of the following:
+    - "allwinner,sun4i-a10-spdif": for the Allwinner A10 SoC
+
+  - reg                      : Offset and length of the register set for the device.
+
+  - interrupts               : Contains the spdif interrupt.
+
+  - dmas             : Generic dma devicetree binding as described in
+                       Documentation/devicetree/bindings/dma/dma.txt.
+
+  - dma-names                : Two dmas have to be defined, "tx" and "rx".
+
+  - clocks           : Contains an entry for each entry in clock-names.
+
+  - clock-names              : Includes the following entries:
+     "apb"             clock for the spdif bus.
+     "spdif"           clock for spdif controller.

Documentation/devicetree/bindings/sound/sun4i,spdif.txt line 31

Quoted 6 lines

Documentation/devicetree/bindings/sound/sun4i,spdif.txt new file +6 -0

+
+Optional:
+
+  - spdif-in         : Enable block for capturing an SPDIF signal.
+
+  - spdif-out                : Enable block for transmitting an SPDIF signal.

Is that a generic property? What values can it hold?

Thanks,
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

sound/soc/sunxi/sun4i-spdif.c new file +9 -0

+#ifdef CONFIG_PM
+static int sun4i_spdif_runtime_suspend(struct device *dev)
+{
+	struct sun4i_spdif_dev *host  = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(host->spdif_clk);
+
+	return 0;
+}

sound/soc/sunxi/sun4i-spdif.c new file +62 -0

+	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+
+	host->pdev = pdev;
+
+	/* Initialize this copy of the CPU DAI driver structure */
+	memcpy(&host->cpu_dai_drv, &sun4i_spdif_dai, sizeof(sun4i_spdif_dai));
+	host->cpu_dai_drv.name = dev_name(&pdev->dev);
+
+	/* Get the addresses */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	host->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+						&sun4i_spdif_regmap_config);
+
+	/* Clocks */
+	host->apb_clk = devm_clk_get(&pdev->dev, "apb");
+	if (IS_ERR(host->apb_clk)) {
+		dev_err(&pdev->dev, "failed to get a apb clock.\n");
+		return PTR_ERR(host->apb_clk);
+	}
+
+	ret = clk_prepare_enable(host->apb_clk);
+	if (ret) {
+		dev_err(&pdev->dev, "try to enable apb_spdif_clk failed\n");
+		return ret;
+	}
+
+	host->spdif_clk = devm_clk_get(&pdev->dev, "spdif");
+	if (IS_ERR(host->spdif_clk)) {
+		dev_err(&pdev->dev, "failed to get a spdif clock.\n");
+		goto exit_clkdisable_apb_clk;
+	}
+
+	host->playback_supported = false;
+	host->capture_supported = false;
+
+	if (of_property_read_bool(np, "spdif-out"))
+		host->playback_supported = true;
+
+	if (!host->playback_supported) {
+		dev_err(&pdev->dev, "no enabled S/PDIF DAI link\n");
+		goto exit_clkdisable_clk;
+	}
+
+	host->dma_params_tx.addr = res->start + SUN4I_SPDIF_TXFIFO;
+	host->dma_params_tx.maxburst = 4;
+	host->dma_params_tx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	host->dma_params_rx.addr = res->start + SUN4I_SPDIF_RXFIFO;
+	host->dma_params_rx.maxburst = 4;
+	host->dma_params_rx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+
+	platform_set_drvdata(pdev, host);
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+				&sun4i_spdif_component, &sun4i_spdif_dai, 1);
+	if (ret)
+		goto exit_clkdisable_clk;

sound/soc/sunxi/sun4i-spdif.c new file +5 -0

+exit_clkdisable_apb_clk:
+	clk_disable_unprepare(host->apb_clk);
+	return ret;
+}
+

sound/soc/sunxi/sun4i-spdif.c new file +5 -0

+		clk_disable_unprepare(host->apb_clk);
+	}
+
+	return 0;
+}

Hi,

It looks mostly good on my side, a few comments though.

Quoted 17 lines · On Tue, Feb 02, 2016 at 03:49:54PM +0100…

sound/soc/sunxi/sun4i-spdif.c new file +17 -0

+#ifdef CONFIG_PM
+static int sun4i_spdif_runtime_suspend(struct device *dev)
+{
+     struct sun4i_spdif_dev *host  = dev_get_drvdata(dev);
+
+     clk_disable_unprepare(host->spdif_clk);
+
+     return 0;
+}
+
+static int sun4i_spdif_runtime_resume(struct device *dev)
+{
+     struct sun4i_spdif_dev *host  = dev_get_drvdata(dev);
+
+     clk_prepare_enable(host->spdif_clk);
+
+     return 0;

Review

Quoted 2 lines

(quoted diff) +2 -0

+}
+#endif /* CONFIG_PM */

You can also shut down the bus clock here. That will reset the device, so you'll have to reinit it in your resume, but since you won't be suspended while you play something, and that you set up most of your controller any way when you start streaming, it shouldn't be a big deal.

Quoted 4 lines

sound/soc/sunxi/sun4i-spdif.c new file +3 -0

+
+static int sun4i_spdif_probe(struct platform_device *pdev)
+{

sound/soc/sunxi/sun4i-spdif.c line 463

Quoted 10 lines

sound/soc/sunxi/sun4i-spdif.c new file +10 -0

+     struct device_node *np = pdev->dev.of_node;
+     struct sun4i_spdif_dev *host;
+     struct resource *res;
+     int ret;
+     void __iomem *base;
+
+     dev_dbg(&pdev->dev, "Entered %s\n", __func__);
+
+     if (!np)
+             return -ENODEV;

You won't probe without DT.

sound/soc/sunxi/sun4i-spdif.c line 468

Quoted 6 lines

sound/soc/sunxi/sun4i-spdif.c new file +5 -0

+
+     if (!of_match_device(sun4i_spdif_of_match, &pdev->dev)) {
+             dev_err(&pdev->dev, "No matched devices found.\n");
+             return -EINVAL;
+     }

And you won't probe if the compatibles don't match.

Quoted 67 lines

sound/soc/sunxi/sun4i-spdif.c new file +66 -0

+     host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
+     if (!host)
+             return -ENOMEM;
+
+     host->pdev = pdev;
+
+     /* Initialize this copy of the CPU DAI driver structure */
+     memcpy(&host->cpu_dai_drv, &sun4i_spdif_dai, sizeof(sun4i_spdif_dai));
+     host->cpu_dai_drv.name = dev_name(&pdev->dev);
+
+     /* Get the addresses */
+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     base = devm_ioremap_resource(&pdev->dev, res);
+     if (IS_ERR(base))
+             return PTR_ERR(base);
+
+     host->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+                                             &sun4i_spdif_regmap_config);
+
+     /* Clocks */
+     host->apb_clk = devm_clk_get(&pdev->dev, "apb");
+     if (IS_ERR(host->apb_clk)) {
+             dev_err(&pdev->dev, "failed to get a apb clock.\n");
+             return PTR_ERR(host->apb_clk);
+     }
+
+     ret = clk_prepare_enable(host->apb_clk);
+     if (ret) {
+             dev_err(&pdev->dev, "try to enable apb_spdif_clk failed\n");
+             return ret;
+     }
+
+     host->spdif_clk = devm_clk_get(&pdev->dev, "spdif");
+     if (IS_ERR(host->spdif_clk)) {
+             dev_err(&pdev->dev, "failed to get a spdif clock.\n");
+             goto exit_clkdisable_apb_clk;
+     }
+
+     host->playback_supported = false;
+     host->capture_supported = false;
+
+     if (of_property_read_bool(np, "spdif-out"))
+             host->playback_supported = true;
+
+     if (!host->playback_supported) {
+             dev_err(&pdev->dev, "no enabled S/PDIF DAI link\n");
+             goto exit_clkdisable_clk;
+     }
+
+     host->dma_params_tx.addr = res->start + SUN4I_SPDIF_TXFIFO;
+     host->dma_params_tx.maxburst = 4;
+     host->dma_params_tx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+     host->dma_params_rx.addr = res->start + SUN4I_SPDIF_RXFIFO;
+     host->dma_params_rx.maxburst = 4;
+     host->dma_params_rx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+
+     platform_set_drvdata(pdev, host);
+
+     ret = devm_snd_soc_register_component(&pdev->dev,
+                             &sun4i_spdif_component, &sun4i_spdif_dai, 1);
+     if (ret)
+             goto exit_clkdisable_clk;
+
+     pm_runtime_enable(&pdev->dev);
+
+     ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);

sound/soc/sunxi/sun4i-spdif.c line 541

Quoted 6 lines

sound/soc/sunxi/sun4i-spdif.c new file +6 -0

+     if (ret)
+             goto exit_clkdisable_clk;
+     return 0;
+
+exit_clkdisable_clk:
+     clk_disable_unprepare(host->spdif_clk);

You disabled a clock that you didn't enable.

Quoted 6 lines

sound/soc/sunxi/sun4i-spdif.c new file +5 -0

+exit_clkdisable_apb_clk:
+     clk_disable_unprepare(host->apb_clk);
+     return ret;
+}
+

sound/soc/sunxi/sun4i-spdif.c line 556

Quoted 10 lines

sound/soc/sunxi/sun4i-spdif.c new file +10 -0

+static int sun4i_spdif_remove(struct platform_device *pdev)
+{
+     struct sun4i_spdif_dev *host = dev_get_drvdata(&pdev->dev);
+
+     snd_soc_unregister_platform(&pdev->dev);
+     snd_soc_unregister_component(&pdev->dev);
+
+     pm_runtime_disable(&pdev->dev);
+
+     if (!IS_ERR(host->spdif_clk)) {

Probe will fail on this condition. If probe failed, remove won't be called.

Quoted 1 line

+ clk_disable_unprepare(host->spdif_clk);

And here as well.

Quoted 9 lines

sound/soc/sunxi/sun4i-spdif.c new file +9 -0

+             clk_disable_unprepare(host->apb_clk);
+     }
+
+     return 0;
+}
+
+static const struct dev_pm_ops sun4i_spdif_pm = {
+     SET_RUNTIME_PM_OPS(sun4i_spdif_runtime_suspend,
+                        sun4i_spdif_runtime_resume, NULL)

sound/soc/sunxi/sun4i-spdif.c line 572

Quoted 6 lines

sound/soc/sunxi/sun4i-spdif.c new file +6 -0

+};
+
+static struct platform_driver sun4i_spdif_driver = {
+     .driver         = {
+             .name   = "sun4i-spdif",
+             .owner  = THIS_MODULE,

This is not needed.

sound/soc/sunxi/sun4i-spdif.c line 574

Quoted 3 lines

sound/soc/sunxi/sun4i-spdif.c new file +2 -0

+             .of_match_table = of_match_ptr(sun4i_spdif_of_match),
+             .pm     = &sun4i_spdif_pm,

IIRC, the pm field is not defined if PM is not set.

Have you tested your driver without PM?

sound/soc/sunxi/sun4i-spdif.c line 586

Quoted 13 lines

sound/soc/sunxi/sun4i-spdif.c new file +12 -0

+     },
+     .probe          = sun4i_spdif_probe,
+     .remove         = sun4i_spdif_remove,
+};
+
+module_platform_driver(sun4i_spdif_driver);
+
+MODULE_AUTHOR("Marcus Cooper <[email protected]>");
+MODULE_AUTHOR("Andrea Venturi <be17068-p0aYb1w59bq9tCD/[email protected]>");
+MODULE_DESCRIPTION("Allwinner sun4i SPDIF SoC Interface");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sun4i-spdif");

Thanks!
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Marcus Cooper (2):
dt-bindings: add sun4i SPDIF transceiver bindings
ASOC: sunxi: Add support for the SPDIF block