Subject: [PATCH 4/5] ASoC: dwc: Add devicetree support for Designware I2S

From: [email-masked] (Andrew Jackson)
Date: Wed, 03 Dec 2014 16:39:08 +0000

Convert to driver to use either platform_data or device-tree for configuration
of the device.  When using device-tree, the I2S block's configuration is read
from the relevant registers: this reduces the amount of information required in
the device tree.

Signed-off-by: Andrew Jackson <[email-masked]>
---
 .../devicetree/bindings/sound/designware-i2s.txt   |   32 +++
 sound/soc/dwc/Kconfig                              |    1 +
 sound/soc/dwc/designware_i2s.c                     |  238 ++++++++++++++++----
 3 files changed, 222 insertions(+), 49 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/sound/designware-i2s.txt

diff --git a/Documentation/devicetree/bindings/sound/designware-i2s.txt b/Documentation/devicetree/bindings/sound/designware-i2s.txt
new file mode 100644
index 0000000..cdee591
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/designware-i2s.txt
@@ -0,0 +1,32 @@
+DesignWare I2S controller
+
+Required properties:
+ - compatible : Must be "snps,designware-i2s"
+ - reg : Must contain I2S core's registers location and length
+ - clocks : Pairs of phandle and specifier referencing the controller's clocks.
+   The controller expects two clocks, the clock used for the APB interface and
+   the clock used as the sampling rate reference clock sample.
+ - clock-names : "apb_plck" for the clock to the APB interface, "i2sclk" for the sample
+   rate reference clock.
+ - dmas: Pairs of phandle and specifier for the DMA channels that are used by
+   the core. The core expects one or two dma channels, one for transmit and one for
+   receive.
+ - dma-names : "tx" for the transmit channel, "rx" for the receive channel.
+
+For more details on the 'dma', 'dma-names', 'clock' and 'clock-names' properties
+please check:
+	* resource-names.txt
+	* clock/clock-bindings.txt
+	* dma/dma.txt
+
+Example:
+
+	soc_i2s: i2s at 7ff90000 {
+		compatible = "snps,designware-i2s";
+		reg = <0x0 0x7ff90000 0x0 0x1000>;
+		clocks = <&scpi_i2sclk 0>, <&soc_refclk100mhz>;
+		clock-names = "i2sclk", "apb_pclk";
+		#sound-dai-cells = <0>;
+		dmas = <&dma0 5>;
+		dma-names = "tx";
+	};
diff --git a/sound/soc/dwc/Kconfig b/sound/soc/dwc/Kconfig
index e334900..d50e085 100644
--- a/sound/soc/dwc/Kconfig
+++ b/sound/soc/dwc/Kconfig
@@ -1,6 +1,7 @@
 config SND_DESIGNWARE_I2S
 	tristate "Synopsys I2S Device Driver"
 	depends on CLKDEV_LOOKUP
+	select SND_SOC_GENERIC_DMAENGINE_PCM
 	help
 	 Say Y or M if you want to add support for I2S driver for
 	 Synopsys desigwnware I2S device. The device supports upto
diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index c497ada..083779d 100644
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -22,6 +22,7 @@
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
 
 /* common register for all channel */
 #define IER		0x000
@@ -54,19 +55,46 @@
 #define I2S_COMP_VERSION	0x01F8
 #define I2S_COMP_TYPE		0x01FC
 
+/*
+ * Component parameter register fields - define the I2S block's
+ * configuration.
+ */
+#define	COMP1_TX_WORDSIZE_3(r)	(((r) & GENMASK(27, 25)) >> 25)
+#define	COMP1_TX_WORDSIZE_2(r)	(((r) & GENMASK(24, 22)) >> 22)
+#define	COMP1_TX_WORDSIZE_1(r)	(((r) & GENMASK(21, 19)) >> 19)
+#define	COMP1_TX_WORDSIZE_0(r)	(((r) & GENMASK(18, 16)) >> 16)
+#define	COMP1_TX_CHANNELS(r)	(((r) & GENMASK(10, 9)) >> 9)
+#define	COMP1_RX_CHANNELS(r)	(((r) & GENMASK(8, 7)) >> 7)
+#define	COMP1_RX_ENABLED(r)	(((r) & BIT(6)) >> 6)
+#define	COMP1_TX_ENABLED(r)	(((r) & BIT(5)) >> 5)
+#define	COMP1_MODE_EN(r)	(((r) & BIT(4)) >> 4)
+#define	COMP1_FIFO_DEPTH_GLOBAL(r)	(((r) & GENMASK(3, 2)) >> 2)
+#define	COMP1_APB_DATA_WIDTH(r)	(((r) & GENMASK(1, 0)) >> 0)
+
+#define	COMP2_RX_WORDSIZE_3(r)	(((r) & GENMASK(12, 10)) >> 10)
+#define	COMP2_RX_WORDSIZE_2(r)	(((r) & GENMASK(9, 7)) >> 7)
+#define	COMP2_RX_WORDSIZE_1(r)	(((r) & GENMASK(5, 3)) >> 3)
+#define	COMP2_RX_WORDSIZE_0(r)	(((r) & GENMASK(2, 0)) >> 0)
+
 #define MAX_CHANNEL_NUM		8
 #define MIN_CHANNEL_NUM		2
 
+union snd_dma_data {
+	struct i2s_dma_data pd;
+	struct snd_dmaengine_dai_dma_data dt;
+};
+
 struct dw_i2s_dev {
 	void __iomem *i2s_base;
 	struct clk *clk;
 	int active;
 	unsigned int capability;
 	struct device *dev;
+	bool using_pd;
 
 	/* data related to DMA transfers b/w i2s and DMAC */
-	struct i2s_dma_data play_dma_data;
-	struct i2s_dma_data capture_dma_data;
+	union snd_dma_data play_dma_data;
+	union snd_dma_data capture_dma_data;
 	struct i2s_clk_config_data config;
 	int (*i2s_clk_cfg)(struct i2s_clk_config_data *config);
 };
@@ -153,7 +181,7 @@ static int dw_i2s_startup(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *cpu_dai)
 {
 	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
-	struct i2s_dma_data *dma_data = NULL;
+	union snd_dma_data *dma_data = NULL;
 
 	if (!(dev->capability & DWC_I2S_RECORD) &&
 			(substream->stream == SNDRV_PCM_STREAM_CAPTURE))
@@ -227,8 +255,7 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 
 	i2s_disable_channels(dev, substream->stream);
 
-	/* Iterate over set of channels - independently controlled.
-	 */
+	/* Iterate over set of channels - independently controlled. */
 	do {
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			i2s_write_reg(dev->i2s_base, TCR(ch_reg),
@@ -251,13 +278,18 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 
 	config->sample_rate = params_rate(params);
 
-	if (!dev->i2s_clk_cfg)
-		return -EINVAL;
+	if (dev->using_pd) {
+		ret = dev->i2s_clk_cfg(config);
+		if (ret < 0) {
+			dev_err(dev->dev, "runtime audio clk config fail\n");
+			return ret;
+		}
+	} else {
+		u32	bitclk;
 
-	ret = dev->i2s_clk_cfg(config);
-	if (ret < 0) {
-		dev_err(dev->dev, "runtime audio clk config fail\n");
-		return ret;
+		/* TODO: Validate sample rate against permissible set */
+		bitclk = config->sample_rate * config->data_width * 2;
+		clk_set_rate(dev->clk, bitclk);
 	}
 
 	return 0;
@@ -331,6 +363,31 @@ static int dw_i2s_resume(struct snd_soc_dai *dai)
 #define dw_i2s_resume	NULL
 #endif
 
+/* Maximum resolution of a channel - not uniformly spaced */
+static const u32 fifo_width[] = {
+	12, 16, 20, 24, 32, 0, 0, 0
+};
+
+/* Width of (DMA) bus */
+static const u32 bus_widths[] = {
+	DMA_SLAVE_BUSWIDTH_1_BYTE,
+	DMA_SLAVE_BUSWIDTH_2_BYTES,
+	DMA_SLAVE_BUSWIDTH_4_BYTES,
+	DMA_SLAVE_BUSWIDTH_UNDEFINED
+};
+
+/* PCM format to support channel resolution */
+static const u32 formats[] = {
+	SNDRV_PCM_FMTBIT_S16_LE,
+	SNDRV_PCM_FMTBIT_S16_LE,
+	SNDRV_PCM_FMTBIT_S24_LE,
+	SNDRV_PCM_FMTBIT_S24_LE,
+	SNDRV_PCM_FMTBIT_S32_LE,
+	0,
+	0,
+	0
+};
+
 static int dw_i2s_probe(struct platform_device *pdev)
 {
 	const struct i2s_platform_data *pdata = pdev->dev.platform_data;
@@ -340,11 +397,6 @@ static int dw_i2s_probe(struct platform_device *pdev)
 	unsigned int cap;
 	struct snd_soc_dai_driver *dw_i2s_dai;
 
-	if (!pdata) {
-		dev_err(&pdev->dev, "Invalid platform data\n");
-		return -EINVAL;
-	}
-
 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 	if (!dev) {
 		dev_warn(&pdev->dev, "kzalloc fail\n");
@@ -373,47 +425,114 @@ static int dw_i2s_probe(struct platform_device *pdev)
 		return PTR_ERR(dev->i2s_base);
 	}
 
-	cap = pdata->cap;
-	dev->capability = cap;
-	dev->i2s_clk_cfg = pdata->i2s_clk_cfg;
+	if (pdata) {
+		dev->using_pd = true;
+		cap = pdata->cap;
+		dev->capability = cap;
+		dev->i2s_clk_cfg = pdata->i2s_clk_cfg;
+		if (!dev->i2s_clk_cfg) {
+			dev_err(&pdev->dev, "no clock device\n");
+			return -ENODEV;
+		}
 
-	/* Set DMA slaves info */
+		/* Set DMA slaves info */
+
+		dev->play_dma_data.pd.data = pdata->play_dma_data;
+		dev->capture_dma_data.pd.data = pdata->capture_dma_data;
+		dev->play_dma_data.pd.addr = res->start + I2S_TXDMA;
+		dev->capture_dma_data.pd.addr = res->start + I2S_RXDMA;
+		dev->play_dma_data.pd.max_burst = 16;
+		dev->capture_dma_data.pd.max_burst = 16;
+		dev->play_dma_data.pd.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		dev->capture_dma_data.pd.addr_width =
+						DMA_SLAVE_BUSWIDTH_2_BYTES;
+		dev->play_dma_data.pd.filter = pdata->filter;
+		dev->capture_dma_data.pd.filter = pdata->filter;
+
+		dev->clk = clk_get(&pdev->dev, NULL);
+		if (IS_ERR(dev->clk))
+			return  PTR_ERR(dev->clk);
+
+		if (cap & DWC_I2S_PLAY) {
+			dev_dbg(&pdev->dev, " designware: play supported\n");
+			dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
+			dw_i2s_dai->playback.channels_max = pdata->channel;
+			dw_i2s_dai->playback.formats = pdata->snd_fmts;
+			dw_i2s_dai->playback.rates = pdata->snd_rates;
+		}
 
-	dev->play_dma_data.data = pdata->play_dma_data;
-	dev->capture_dma_data.data = pdata->capture_dma_data;
-	dev->play_dma_data.addr = res->start + I2S_TXDMA;
-	dev->capture_dma_data.addr = res->start + I2S_RXDMA;
-	dev->play_dma_data.max_burst = 16;
-	dev->capture_dma_data.max_burst = 16;
-	dev->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
-	dev->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
-	dev->play_dma_data.filter = pdata->filter;
-	dev->capture_dma_data.filter = pdata->filter;
+		if (cap & DWC_I2S_RECORD) {
+			dev_dbg(&pdev->dev, "designware: record supported\n");
+			dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
+			dw_i2s_dai->capture.channels_max = pdata->channel;
+			dw_i2s_dai->capture.formats = pdata->snd_fmts;
+			dw_i2s_dai->capture.rates = pdata->snd_rates;
+		}
+	} else {
+		/*
+		 * Read component parameter registers to extract
+		 * the I2S block's configuration.
+		 */
+		u32 comp1 = i2s_read_reg(dev->i2s_base, I2S_COMP_PARAM_1);
+		u32 comp2 = i2s_read_reg(dev->i2s_base, I2S_COMP_PARAM_2);
+		u32 bus_width = bus_widths[COMP1_APB_DATA_WIDTH(comp1)];
+		u32 fifo_depth = 1 << (1 + COMP1_FIFO_DEPTH_GLOBAL(comp1));
+		u32 max_size;
+
+		dev->using_pd = false;
+
+		dev->clk = devm_clk_get(&pdev->dev, "i2sclk");
+		if (IS_ERR(dev->clk))
+			return  PTR_ERR(dev->clk);
+
+		/*
+		 * Code presumes all channels are configured with the same
+		 * word size.
+		 */
+		if (COMP1_TX_ENABLED(comp1)) {
+			dev_dbg(&pdev->dev, "playback capable\n");
+
+			dev->capability |= DWC_I2S_PLAY;
+			max_size = COMP1_TX_WORDSIZE_0(comp1);
+			dev->play_dma_data.dt.addr = res->start + I2S_TXDMA;
+			dev->play_dma_data.dt.addr_width = bus_width;
+			dev->play_dma_data.dt.chan_name = "TX";
+			dev->play_dma_data.dt.fifo_size = fifo_depth *
+				(fifo_width[max_size]) >> 8;
+			dev->play_dma_data.dt.maxburst = 16;
+			dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
+			dw_i2s_dai->playback.channels_max =
+					1 << (COMP1_TX_CHANNELS(comp1) + 1);
+			dw_i2s_dai->playback.formats = formats[max_size];
+			dw_i2s_dai->playback.rates = SNDRV_PCM_RATE_8000_192000;
+		}
+		if (COMP1_RX_ENABLED(comp1)) {
+			dev_dbg(&pdev->dev, "record capable\n");
+
+			dev->capability |= DWC_I2S_RECORD;
+			max_size = COMP2_RX_WORDSIZE_0(comp2);
+			dev->capture_dma_data.dt.addr = res->start + I2S_RXDMA;
+			dev->capture_dma_data.dt.addr_width = bus_width;
+			dev->capture_dma_data.dt.chan_name = "RX";
+			dev->capture_dma_data.dt.fifo_size = fifo_depth *
+				(fifo_width[max_size] >> 8);
+			dev->capture_dma_data.dt.maxburst = 16;
+			dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
+			dw_i2s_dai->capture.channels_max =
+					1 << (COMP1_RX_CHANNELS(comp1) + 1);
+			dw_i2s_dai->capture.formats = formats[max_size];
+			dw_i2s_dai->capture.rates = SNDRV_PCM_RATE_8000_192000;
+		}
+	}
 
-	dev->clk = clk_get(&pdev->dev, NULL);
-	if (IS_ERR(dev->clk))
-		return  PTR_ERR(dev->clk);
+	ret = clk_prepare(dev->clk);
+	if (ret < 0)
+		goto err_clk_put;
 
 	ret = clk_enable(dev->clk);
 	if (ret < 0)
 		goto err_clk_put;
 
-	if (cap & DWC_I2S_PLAY) {
-		dev_dbg(&pdev->dev, " designware: play supported\n");
-		dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
-		dw_i2s_dai->playback.channels_max = pdata->channel;
-		dw_i2s_dai->playback.formats = pdata->snd_fmts;
-		dw_i2s_dai->playback.rates = pdata->snd_rates;
-	}
-
-	if (cap & DWC_I2S_RECORD) {
-		dev_dbg(&pdev->dev, "designware: record supported\n");
-		dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
-		dw_i2s_dai->capture.channels_max = pdata->channel;
-		dw_i2s_dai->capture.formats = pdata->snd_fmts;
-		dw_i2s_dai->capture.rates = pdata->snd_rates;
-	}
-
 	dev->dev = &pdev->dev;
 	dev_set_drvdata(&pdev->dev, dev);
 	ret = snd_soc_register_component(&pdev->dev, &dw_i2s_component,
@@ -423,6 +542,15 @@ static int dw_i2s_probe(struct platform_device *pdev)
 		goto err_clk_disable;
 	}
 
+	if (!dev->using_pd) {
+		ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Could not register PCM: %d\n", ret);
+			return ret;
+		}
+	}
+
 	return 0;
 
 err_clk_disable:
@@ -443,12 +571,24 @@ static int dw_i2s_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id dw_i2s_of_match[] = {
+	{ .compatible = "snps,designware-i2s",	 },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, dw_i2s_of_match);
+#endif
+
 static struct platform_driver dw_i2s_driver = {
 	.probe		= dw_i2s_probe,
 	.remove		= dw_i2s_remove,
 	.driver		= {
 		.name	= "designware-i2s",
 		.owner	= THIS_MODULE,
+#ifdef CONFIG_OF
+		.of_match_table = dw_i2s_of_match,
+#endif
 	},
 };
 
-- 
1.7.1