Add Chameleon v3 ASoC audio

Merge series from Paweł Anikiel <pan@semihalf.com>:

The Google Chameleon v3 is a device made for testing audio and video
paths of other devices. This patchset adds support for ASoC audio on
this device. It has two audio sources: HDMI audio from the it68051 chip
(RX only), and analog audio from the ssm2603 chip (RX and TX).

The patchset adds the ASoC platform and codec drivers.

Documentation/devicetree/bindings/sound/google,chv3-codec.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/google,chv3-codec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Chameleon v3 audio codec
+
+maintainers:
+  - Paweł Anikiel <pan@semihalf.com>
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: google,chv3-codec
+
+  "#sound-dai-cells":
+    const: 0
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    audio-codec {
+        compatible = "google,chv3-codec";
+    };

Documentation/devicetree/bindings/sound/google,chv3-i2s.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/google,chv3-i2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Chameleon v3 I2S device
+
+maintainers:
+  - Paweł Anikiel <pan@semihalf.com>
+
+description: |
+  I2S device for the Google Chameleon v3. The device handles both RX
+  and TX using a producer/consumer ring buffer design.
+
+properties:
+  compatible:
+    const: google,chv3-i2s
+
+  reg:
+    items:
+      - description: core registers
+      - description: irq registers
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    i2s@c0060300 {
+        compatible = "google,chv3-i2s";
+        reg = <0xc0060300 0x100>,
+              <0xc0060f00 0x10>;
+        interrupts = <GIC_SPI 20 IRQ_TYPE_LEVEL_HIGH>;
+    };

sound/soc/Kconfig

@@ -75,6 +75,7 @@ source "sound/soc/bcm/Kconfig"
 source "sound/soc/cirrus/Kconfig"
 source "sound/soc/dwc/Kconfig"
 source "sound/soc/fsl/Kconfig"
+source "sound/soc/google/Kconfig"
 source "sound/soc/hisilicon/Kconfig"
 source "sound/soc/jz4740/Kconfig"
 source "sound/soc/kirkwood/Kconfig"

sound/soc/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_SND_SOC)	+= bcm/
 obj-$(CONFIG_SND_SOC)	+= cirrus/
 obj-$(CONFIG_SND_SOC)	+= dwc/
 obj-$(CONFIG_SND_SOC)	+= fsl/
+obj-$(CONFIG_SND_SOC)	+= google/
 obj-$(CONFIG_SND_SOC)	+= hisilicon/
 obj-$(CONFIG_SND_SOC)	+= jz4740/
 obj-$(CONFIG_SND_SOC)	+= img/

sound/soc/codecs/Kconfig

@@ -57,6 +57,7 @@ config SND_SOC_ALL_CODECS
 	imply SND_SOC_AW88395
 	imply SND_SOC_BT_SCO
 	imply SND_SOC_BD28623
+	imply SND_SOC_CHV3_CODEC
 	imply SND_SOC_CQ0093VC
 	imply SND_SOC_CROS_EC_CODEC
 	imply SND_SOC_CS35L32
@@ -644,6 +645,13 @@ config SND_SOC_BD28623
 config SND_SOC_BT_SCO
 	tristate "Dummy BT SCO codec driver"
 
+config SND_SOC_CHV3_CODEC
+	tristate "Google Chameleon v3 codec driver"
+	help
+	  Enable support for the Google Chameleon v3 audio codec.
+	  This codec does not have a control interface, it always outputs
+	  8 channel S32_LE audio.
+
 config SND_SOC_CPCAP
 	tristate "Motorola CPCAP codec"
 	depends on MFD_CPCAP || COMPILE_TEST

sound/soc/codecs/Makefile

@@ -51,6 +51,7 @@ snd-soc-aw88395-objs := aw88395/aw88395.o \
 			aw88395/aw88395_device.o
 snd-soc-bd28623-objs := bd28623.o
 snd-soc-bt-sco-objs := bt-sco.o
+snd-soc-chv3-codec-objs := chv3-codec.o
 snd-soc-cpcap-objs := cpcap.o
 snd-soc-cq93vc-objs := cq93vc.o
 snd-soc-cros-ec-codec-objs := cros_ec_codec.o
@@ -427,6 +428,7 @@ obj-$(CONFIG_SND_SOC_AW88395_LIB) += snd-soc-aw88395-lib.o
 obj-$(CONFIG_SND_SOC_AW88395)	+=snd-soc-aw88395.o
 obj-$(CONFIG_SND_SOC_BD28623)	+= snd-soc-bd28623.o
 obj-$(CONFIG_SND_SOC_BT_SCO)	+= snd-soc-bt-sco.o
+obj-$(CONFIG_SND_SOC_CHV3_CODEC) += snd-soc-chv3-codec.o
 obj-$(CONFIG_SND_SOC_CQ0093VC) += snd-soc-cq93vc.o
 obj-$(CONFIG_SND_SOC_CPCAP)	+= snd-soc-cpcap.o
 obj-$(CONFIG_SND_SOC_CROS_EC_CODEC)	+= snd-soc-cros-ec-codec.o

sound/soc/codecs/chv3-codec.c

+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <sound/soc.h>
+
+static struct snd_soc_dai_driver chv3_codec_dai = {
+	.name = "chv3-codec-hifi",
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 8,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE,
+	},
+};
+
+static const struct snd_soc_component_driver soc_component_dev_chv3_codec = {
+};
+
+static int chv3_codec_probe(struct platform_device *pdev)
+{
+	return devm_snd_soc_register_component(&pdev->dev,
+		&soc_component_dev_chv3_codec, &chv3_codec_dai, 1);
+}
+
+static const struct of_device_id chv3_codec_of_match[] = {
+	{ .compatible = "google,chv3-codec", },
+	{ }
+};
+
+static struct platform_driver chv3_codec_platform_driver = {
+	.driver = {
+		.name = "chv3-codec",
+		.of_match_table = chv3_codec_of_match,
+	},
+	.probe = chv3_codec_probe,
+};
+module_platform_driver(chv3_codec_platform_driver);
+
+MODULE_DESCRIPTION("ASoC Chameleon v3 codec driver");
+MODULE_AUTHOR("Pawel Anikiel <pan@semihalf.com>");
+MODULE_LICENSE("GPL");

sound/soc/google/Kconfig

+# SPDX-License-Identifier: GPL-2.0-only
+
+config SND_SOC_CHV3_I2S
+	tristate "Google Chameleon v3 I2S device"
+	help
+	  Enable support for the Google Chameleon v3 I2S device.

sound/soc/google/Makefile

+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_SND_SOC_CHV3_I2S) += chv3-i2s.o

sound/soc/google/chv3-i2s.c

+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <sound/soc.h>
+
+/*
+ * The I2S interface consists of two ring buffers - one for RX and one for
+ * TX.  A ring buffer has a producer index and a consumer index. Depending
+ * on which way the data is flowing, either the software or the hardware
+ * writes data and updates the producer index, and the other end reads data
+ * and updates the consumer index.
+ *
+ * The pointer managed by software is updated using the .ack callback
+ * (see chv3_dma_ack). This seems to be the only way to reliably obtain
+ * the appl_ptr from within the driver and pass it to hardware.
+ *
+ * Because of the two pointer design, the ring buffer can never be full. With
+ * capture this isn't a problem, because the hardware being the producer
+ * will wait for the consumer index to move out of the way.  With playback,
+ * however, this is problematic, because ALSA wants to fill up the buffer
+ * completely when waiting for hardware. In the .ack callback, the driver
+ * would have to wait for the consumer index to move out of the way by
+ * busy-waiting, which would keep stalling the kernel for quite a long time.
+ *
+ * The workaround to this problem is to "lie" to ALSA that the hw_pointer
+ * is one frame behind what it actually is (see chv3_dma_pointer). This
+ * way, ALSA will not try to fill up the entire buffer, and all callbacks
+ * are wait-free.
+ */
+
+#define I2S_TX_ENABLE		0x00
+#define I2S_TX_BASE_ADDR	0x04
+#define I2S_TX_BUFFER_SIZE	0x08
+#define I2S_TX_PRODUCER_IDX	0x0c
+#define I2S_TX_CONSUMER_IDX	0x10
+#define I2S_RX_ENABLE		0x14
+#define I2S_RX_BASE_ADDR	0x18
+#define I2S_RX_BUFFER_SIZE	0x1c
+#define I2S_RX_PRODUCER_IDX	0x20
+#define I2S_RX_CONSUMER_IDX	0x24
+
+#define I2S_SOFT_RESET		0x2c
+#define I2S_SOFT_RESET_RX_BIT	0x1
+#define I2S_SOFT_RESET_TX_BIT	0x2
+
+#define I2S_RX_IRQ		0x4c
+#define I2S_RX_IRQ_CONST	0x50
+#define I2S_TX_IRQ		0x54
+#define I2S_TX_IRQ_CONST	0x58
+
+#define I2S_IRQ_MASK	0x8
+#define I2S_IRQ_CLR	0xc
+#define I2S_IRQ_RX_BIT	0x1
+#define I2S_IRQ_TX_BIT	0x2
+
+#define I2S_MAX_BUFFER_SIZE	0x200000
+
+struct chv3_i2s_dev {
+	struct device *dev;
+	void __iomem *iobase;
+	void __iomem *iobase_irq;
+	struct snd_pcm_substream *rx_substream;
+	struct snd_pcm_substream *tx_substream;
+	int tx_bytes_to_fetch;
+};
+
+static struct snd_soc_dai_driver chv3_i2s_dai = {
+	.name = "chv3-i2s",
+	.capture = {
+		.channels_min = 1,
+		.channels_max = 128,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.rate_min = 8000,
+		.rate_max = 96000,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE,
+	},
+	.playback = {
+		.channels_min = 1,
+		.channels_max = 128,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.rate_min = 8000,
+		.rate_max = 96000,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE,
+	},
+};
+
+static const struct snd_pcm_hardware chv3_dma_hw = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER,
+	.buffer_bytes_max = I2S_MAX_BUFFER_SIZE,
+	.period_bytes_min = 64,
+	.period_bytes_max = 8192,
+	.periods_min = 4,
+	.periods_max = 256,
+};
+
+static inline void chv3_i2s_wr(struct chv3_i2s_dev *i2s, int offset, u32 val)
+{
+	writel(val, i2s->iobase + offset);
+}
+
+static inline u32 chv3_i2s_rd(struct chv3_i2s_dev *i2s, int offset)
+{
+	return readl(i2s->iobase + offset);
+}
+
+static irqreturn_t chv3_i2s_isr(int irq, void *data)
+{
+	struct chv3_i2s_dev *i2s = data;
+	u32 reg;
+
+	reg = readl(i2s->iobase_irq + I2S_IRQ_CLR);
+	if (!reg)
+		return IRQ_NONE;
+
+	if (reg & I2S_IRQ_RX_BIT)
+		snd_pcm_period_elapsed(i2s->rx_substream);
+
+	if (reg & I2S_IRQ_TX_BIT)
+		snd_pcm_period_elapsed(i2s->tx_substream);
+
+	writel(reg, i2s->iobase_irq + I2S_IRQ_CLR);
+
+	return IRQ_HANDLED;
+}
+
+static int chv3_dma_open(struct snd_soc_component *component,
+			 struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+	int res;
+
+	snd_soc_set_runtime_hwparams(substream, &chv3_dma_hw);
+
+	res = snd_pcm_hw_constraint_pow2(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_BUFFER_BYTES);
+	if (res)
+		return res;
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		i2s->rx_substream = substream;
+	else
+		i2s->tx_substream = substream;
+
+	return 0;
+}
+static int chv3_dma_close(struct snd_soc_component *component,
+			  struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+
+	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
+		chv3_i2s_wr(i2s, I2S_RX_ENABLE, 0);
+	else
+		chv3_i2s_wr(i2s, I2S_TX_ENABLE, 0);
+
+	return 0;
+}
+
+static int chv3_dma_pcm_construct(struct snd_soc_component *component,
+				  struct snd_soc_pcm_runtime *rtd)
+{
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+	struct snd_pcm_substream *substream;
+	int res;
+
+	substream = rtd->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
+	if (substream) {
+		res = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, i2s->dev,
+				I2S_MAX_BUFFER_SIZE, &substream->dma_buffer);
+		if (res)
+			return res;
+	}
+
+	substream = rtd->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
+	if (substream) {
+		res = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, i2s->dev,
+				I2S_MAX_BUFFER_SIZE, &substream->dma_buffer);
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+static int chv3_dma_hw_params(struct snd_soc_component *component,
+			      struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *params)
+{
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	return 0;
+}
+
+static int chv3_dma_prepare(struct snd_soc_component *component,
+			    struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+	unsigned int buffer_bytes, period_bytes, period_size;
+
+	buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+	period_bytes = snd_pcm_lib_period_bytes(substream);
+	period_size = substream->runtime->period_size;
+
+	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
+		chv3_i2s_wr(i2s, I2S_SOFT_RESET, I2S_SOFT_RESET_RX_BIT);
+		chv3_i2s_wr(i2s, I2S_RX_BASE_ADDR, substream->dma_buffer.addr);
+		chv3_i2s_wr(i2s, I2S_RX_BUFFER_SIZE, buffer_bytes);
+		chv3_i2s_wr(i2s, I2S_RX_IRQ, (period_size << 8) | 1);
+		chv3_i2s_wr(i2s, I2S_RX_ENABLE, 1);
+	} else {
+		chv3_i2s_wr(i2s, I2S_SOFT_RESET, I2S_SOFT_RESET_TX_BIT);
+		chv3_i2s_wr(i2s, I2S_TX_BASE_ADDR, substream->dma_buffer.addr);
+		chv3_i2s_wr(i2s, I2S_TX_BUFFER_SIZE, buffer_bytes);
+		chv3_i2s_wr(i2s, I2S_TX_IRQ, ((period_bytes / i2s->tx_bytes_to_fetch) << 8) | 1);
+		chv3_i2s_wr(i2s, I2S_TX_ENABLE, 1);
+	}
+	writel(I2S_IRQ_RX_BIT | I2S_IRQ_TX_BIT, i2s->iobase_irq + I2S_IRQ_MASK);
+
+	return 0;
+}
+
+static snd_pcm_uframes_t chv3_dma_pointer(struct snd_soc_component *component,
+					  struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+	u32 frame_bytes, buffer_bytes;
+	u32 idx_bytes;
+
+	frame_bytes = substream->runtime->frame_bits * 8;
+	buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
+
+	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
+		idx_bytes = chv3_i2s_rd(i2s, I2S_RX_PRODUCER_IDX);
+	} else {
+		idx_bytes = chv3_i2s_rd(i2s, I2S_TX_CONSUMER_IDX);
+		/* lag the pointer by one frame */
+		idx_bytes = (idx_bytes - frame_bytes) & (buffer_bytes - 1);
+	}
+
+	return bytes_to_frames(substream->runtime, idx_bytes);
+}
+
+static int chv3_dma_ack(struct snd_soc_component *component,
+			struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct chv3_i2s_dev *i2s = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
+	unsigned int bytes, idx;
+
+	bytes = frames_to_bytes(runtime, runtime->control->appl_ptr);
+	idx = bytes & (snd_pcm_lib_buffer_bytes(substream) - 1);
+
+	if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
+		chv3_i2s_wr(i2s, I2S_RX_CONSUMER_IDX, idx);
+	else
+		chv3_i2s_wr(i2s, I2S_TX_PRODUCER_IDX, idx);
+
+	return 0;
+}
+
+static const struct snd_soc_component_driver chv3_i2s_comp = {
+	.name = "chv3-i2s-comp",
+	.open = chv3_dma_open,
+	.close = chv3_dma_close,
+	.pcm_construct = chv3_dma_pcm_construct,
+	.hw_params = chv3_dma_hw_params,
+	.prepare = chv3_dma_prepare,
+	.pointer = chv3_dma_pointer,
+	.ack = chv3_dma_ack,
+};
+
+static int chv3_i2s_probe(struct platform_device *pdev)
+{
+	struct chv3_i2s_dev *i2s;
+	int res;
+	int irq;
+
+	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s)
+		return -ENOMEM;
+
+	i2s->iobase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(i2s->iobase))
+		return PTR_ERR(i2s->iobase);
+
+	i2s->iobase_irq = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(i2s->iobase_irq))
+		return PTR_ERR(i2s->iobase_irq);
+
+	i2s->tx_bytes_to_fetch = (chv3_i2s_rd(i2s, I2S_TX_IRQ_CONST) >> 8) & 0xffff;
+
+	i2s->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, i2s);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENXIO;
+	res = devm_request_irq(i2s->dev, irq, chv3_i2s_isr, 0, "chv3-i2s", i2s);
+	if (res)
+		return res;
+
+	res = devm_snd_soc_register_component(&pdev->dev, &chv3_i2s_comp,
+					      &chv3_i2s_dai, 1);
+	if (res) {
+		dev_err(&pdev->dev, "couldn't register component: %d\n", res);
+		return res;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id chv3_i2s_of_match[] = {
+	{ .compatible = "google,chv3-i2s" },
+	{},
+};
+
+static struct platform_driver chv3_i2s_driver = {
+	.probe = chv3_i2s_probe,
+	.driver = {
+		.name = "chv3-i2s",
+		.of_match_table = chv3_i2s_of_match,
+	},
+};
+
+module_platform_driver(chv3_i2s_driver);
+
+MODULE_AUTHOR("Pawel Anikiel <pan@semihalf.com>");
+MODULE_DESCRIPTION("Chameleon v3 I2S interface");
+MODULE_LICENSE("GPL");