[PATCH 1/4] dt: Add bindings documentation for the ADI AXI-I2S controller

[PATCH 1/4] dt: Add bindings documentation for the ADI AXI-I2S controller

[Lars-Peter Clausen]

This patch adds the devicetree documentation for the ADI AXI-SPDIF audio
controller. The controller has:
 * One set of memory mapped register
 * Two clocks, one for the memory mapped register interface, one used as the
   audio reference clock
 * One DMA interface each for the transmit and receive data

Signed-off-by: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
Cc: Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Cc: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
Cc: Ian Campbell <ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 .../devicetree/bindings/sound/adi,axi-i2s.txt      | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/adi,axi-i2s.txt

diff --git a/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt b/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt
new file mode 100644
index 0000000..d9c0e53
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/adi,axi-i2s.txt
@@ -0,0 +1,29 @@
+ADI AXI-I2S controller
+
+Required properties:
+ - compatible : Must be "adi,axi-i2s-1.00.a"
+ - reg : Must contain I2S registers location and length
+ - clocks : Clock specifier providing a handle to the controller's clocks. The
+   controller expects two clocks, the clock used for the AXI interface and the
+   clock used as thei sampling rate reference clock sample.
+ - clock-names : "axi" for the clock to the AXI interface, "ref" for the sample
+   rate reference clock.
+ - dma : Specifiers for the DMA channels that are used by the core.
+ - 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:
+
+	i2s: i2s@0x77600000 {
+		compatible = "adi,axi-i2s-1.00.a";
+		reg = <0x77600000 0x1000>;
+		clocks = <&clk 15 &audio_clock>;
+		clock-names = "axi", "ref";
+		dmas = <&ps7_dma 0 &ps7_dma 1>;
+		dma-names = "tx", "rx";
+	};
-- 
1.8.0

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[PATCH 2/4] ASoC: Add support for the Analog Devices AXI-I2S core

[Lars-Peter Clausen]

This patch adds support for the AXI-I2S core. The core implements a simple
bidirectional I2S transceiver and is used by Analog Devices in some of their
reference designs for various FPGA platforms.

The patch also adds a simple ASoC PCM driver for the PL330 DMA controller using
the generic dmaengine PCM driver. This driver is only temporary can be removed
once we have all the infrastructure in place to query information like maximum
transfer size directly from the dmaengine driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
Has a compile time dependency on topic/dma
---
 sound/soc/Kconfig       |   1 +
 sound/soc/Makefile      |   1 +
 sound/soc/adi/Kconfig   |  13 +++
 sound/soc/adi/Makefile  |   3 +
 sound/soc/adi/axi-i2s.c | 276 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 294 insertions(+)
 create mode 100644 sound/soc/adi/Kconfig
 create mode 100644 sound/soc/adi/Makefile
 create mode 100644 sound/soc/adi/axi-i2s.c

diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 5138b84..866dfec 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -31,6 +31,7 @@ config SND_SOC_GENERIC_DMAENGINE_PCM
 	select SND_DMAENGINE_PCM
 
 # All the supported SoCs
+source "sound/soc/adi/Kconfig"
 source "sound/soc/atmel/Kconfig"
 source "sound/soc/au1x/Kconfig"
 source "sound/soc/blackfin/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 8b9e701..c70c7f7 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -8,6 +8,7 @@ endif
 obj-$(CONFIG_SND_SOC)	+= snd-soc-core.o
 obj-$(CONFIG_SND_SOC)	+= codecs/
 obj-$(CONFIG_SND_SOC)	+= generic/
+obj-$(CONFIG_SND_SOC)	+= adi/
 obj-$(CONFIG_SND_SOC)	+= atmel/
 obj-$(CONFIG_SND_SOC)	+= au1x/
 obj-$(CONFIG_SND_SOC)	+= blackfin/
diff --git a/sound/soc/adi/Kconfig b/sound/soc/adi/Kconfig
new file mode 100644
index 0000000..14bb385
--- /dev/null
+++ b/sound/soc/adi/Kconfig
@@ -0,0 +1,13 @@
+config SND_SOC_ADI
+	tristate "Audio support for Analog Devices reference designs"
+	depends on SND_SOC && (MICROBLAZE || ARCH_ZYNQ || COMPILE_TEST)
+	help
+	  Audio support for various reference designs by Analog Devices.
+
+config SND_SOC_ADI_AXI_I2S
+	tristate "AXI-I2S support"
+	depends on SND_SOC_ADI
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  ASoC driver for the Analog Devices AXI-I2S softcore peripheral.
diff --git a/sound/soc/adi/Makefile b/sound/soc/adi/Makefile
new file mode 100644
index 0000000..d32c21a
--- /dev/null
+++ b/sound/soc/adi/Makefile
@@ -0,0 +1,3 @@
+snd-soc-adi-axi-i2s-objs := axi-i2s.o
+
+obj-$(CONFIG_SND_SOC_ADI_AXI_I2S) += snd-soc-adi-axi-i2s.o
diff --git a/sound/soc/adi/axi-i2s.c b/sound/soc/adi/axi-i2s.c
new file mode 100644
index 0000000..107877e
--- /dev/null
+++ b/sound/soc/adi/axi-i2s.c
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2012-2013, Analog Devices Inc.
+ * Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+
+#define AXI_I2S_REG_RESET	0x00
+#define AXI_I2S_REG_CTRL	0x04
+#define AXI_I2S_REG_CLK_CTRL	0x08
+#define AXI_I2S_REG_STATUS	0x10
+
+#define AXI_I2S_REG_RX_FIFO	0x28
+#define AXI_I2S_REG_TX_FIFO	0x2C
+
+#define AXI_I2S_RESET_GLOBAL	BIT(0)
+#define AXI_I2S_RESET_TX_FIFO	BIT(1)
+#define AXI_I2S_RESET_RX_FIFO	BIT(2)
+
+#define AXI_I2S_CTRL_TX_EN	BIT(0)
+#define AXI_I2S_CTRL_RX_EN	BIT(1)
+
+#define AXI_I2S_BITS_PER_FRAME 64
+
+struct axi_i2s {
+	struct regmap *regmap;
+	struct clk *clk;
+	struct clk *clk_ref;
+
+	struct snd_soc_dai_driver dai_driver;
+
+	struct snd_dmaengine_dai_dma_data capture_dma_data;
+	struct snd_dmaengine_dai_dma_data playback_dma_data;
+
+	struct snd_ratnum ratnum;
+	struct snd_pcm_hw_constraint_ratnums rate_constraints;
+};
+
+static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+	struct snd_soc_dai *dai)
+{
+	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned int mask, val;
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		mask = AXI_I2S_CTRL_RX_EN;
+	else
+		mask = AXI_I2S_CTRL_TX_EN;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		val = mask;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val);
+
+	return 0;
+}
+
+static int axi_i2s_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
+{
+	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned int bclk_div, frame_size;
+	unsigned int bclk_rate;
+
+	bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME;
+
+	frame_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;
+	bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1;
+
+	regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (frame_size << 16) |
+		bclk_div);
+
+	return 0;
+}
+
+static int axi_i2s_startup(struct snd_pcm_substream *substream,
+	struct snd_soc_dai *dai)
+{
+	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	uint32_t mask;
+	int ret;
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		mask = AXI_I2S_RESET_RX_FIFO;
+	else
+		mask = AXI_I2S_RESET_TX_FIFO;
+
+	regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask);
+
+	ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
+			   SNDRV_PCM_HW_PARAM_RATE,
+			   &i2s->rate_constraints);
+	if (ret)
+		return ret;
+
+	return clk_prepare_enable(i2s->clk_ref);
+}
+
+static void axi_i2s_shutdown(struct snd_pcm_substream *substream,
+	struct snd_soc_dai *dai)
+{
+	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	clk_disable_unprepare(i2s->clk_ref);
+}
+
+static int axi_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &i2s->playback_dma_data,
+		&i2s->capture_dma_data);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops axi_i2s_dai_ops = {
+	.startup = axi_i2s_startup,
+	.shutdown = axi_i2s_shutdown,
+	.trigger = axi_i2s_trigger,
+	.hw_params = axi_i2s_hw_params,
+};
+
+static struct snd_soc_dai_driver axi_i2s_dai = {
+	.probe = axi_i2s_dai_probe,
+	.playback = {
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_KNOT,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE,
+	},
+	.capture = {
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_KNOT,
+		.formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE,
+	},
+	.ops = &axi_i2s_dai_ops,
+	.symmetric_rates = 1,
+};
+
+static const struct snd_soc_component_driver axi_i2s_component = {
+	.name		= "axi-i2s",
+};
+
+static const struct regmap_config axi_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = AXI_I2S_REG_STATUS,
+};
+
+static int axi_i2s_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct axi_i2s *i2s;
+	void __iomem *base;
+	int ret;
+
+	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, i2s);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!base)
+		return -EBUSY;
+
+	i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+		&axi_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap))
+		return PTR_ERR(i2s->regmap);
+
+	i2s->clk = devm_clk_get(&pdev->dev, "axi");
+	if (IS_ERR(i2s->clk))
+		return PTR_ERR(i2s->clk);
+
+	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
+	if (IS_ERR(i2s->clk_ref))
+		return PTR_ERR(i2s->clk_ref);
+
+	ret = clk_prepare_enable(i2s->clk);
+	if (ret)
+		return ret;
+
+	i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO;
+	i2s->playback_dma_data.addr_width = 4;
+	i2s->playback_dma_data.maxburst = 1;
+
+	i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO;
+	i2s->capture_dma_data.addr_width = 4;
+	i2s->capture_dma_data.maxburst = 1;
+
+	i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME;
+	i2s->ratnum.den_step = 1;
+	i2s->ratnum.den_min = 1;
+	i2s->ratnum.den_max = 64;
+
+	i2s->rate_constraints.rats = &i2s->ratnum;
+	i2s->rate_constraints.nrats = 1;
+
+	regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL);
+
+	ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component,
+					 &axi_i2s_dai, 1);
+	if (ret)
+		goto err_clk_disable;
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL,
+			SND_DMAENGINE_PCM_FLAG_NO_RESIDUE);
+	if (ret)
+		goto err_clk_disable;
+
+err_clk_disable:
+	clk_disable_unprepare(i2s->clk);
+	return ret;
+}
+
+static int axi_i2s_dev_remove(struct platform_device *pdev)
+{
+	struct axi_i2s *i2s = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(i2s->clk);
+
+	return 0;
+}
+
+static const struct of_device_id axi_i2s_of_match[] = {
+	{ .compatible = "adi,axi-i2s-1.00.a", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, axi_i2s_of_match);
+
+static struct platform_driver axi_i2s_driver = {
+	.driver = {
+		.name = "axi-i2s",
+		.owner = THIS_MODULE,
+		.of_match_table = axi_i2s_of_match,
+	},
+	.probe = axi_i2s_probe,
+	.remove = axi_i2s_dev_remove,
+};
+module_platform_driver(axi_i2s_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("AXI I2S driver");
+MODULE_LICENSE("GPL");
-- 
1.8.0

Re: [PATCH 2/4] ASoC: Add support for the Analog Devices AXI-I2S core

[Mark Brown]

[-- Attachment #1.1: Type: text/plain, Size: 1698 bytes --]

On Thu, Nov 28, 2013 at 08:02:50PM +0100, Lars-Peter Clausen wrote:

A few really minor things below.

> The patch also adds a simple ASoC PCM driver for the PL330 DMA controller using
> the generic dmaengine PCM driver. This driver is only temporary can be removed
> once we have all the infrastructure in place to query information like maximum
> transfer size directly from the dmaengine driver.

It's not really a driver as such, it's just specifying some extra
parameters - I'd expect you're going to need to keep the addresses at
least.  It's probably more accurate to say that at the minute there's
some assumptions in the driver about the DMA controller configuration
that will be required which should be removable in future?

> +config SND_SOC_ADI
> +	tristate "Audio support for Analog Devices reference designs"
> +	depends on SND_SOC && (MICROBLAZE || ARCH_ZYNQ || COMPILE_TEST)
> +	help
> +	  Audio support for various reference designs by Analog Devices.
> +

Given that this is a FPGA IP I'd also expect it to be available on
SOCFPGA and probably other things.  For the Designware I2S controller we
just don't have any platform dependency at all.

There's no need for the SND_SOC dependency, all the subdirectory
Kconfigs are only included in an if SND_SOC block.

> +	frame_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;

This isn't obvious - usually the frame size is the number of bits per
frame.  Looking at the code I guess the hardware is more flexible than
the driver allows at the minute?

> +	regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (frame_size << 16) |
> +		bclk_div);

update_bits() would be more obvious, though for a memory mapped device
it really makes no difference.

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Re: [PATCH 2/4] ASoC: Add support for the Analog Devices AXI-I2S core

[Lars-Peter Clausen]

On 11/29/2013 12:58 PM, Mark Brown wrote:
> On Thu, Nov 28, 2013 at 08:02:50PM +0100, Lars-Peter Clausen wrote:
> 
> A few really minor things below.
> 
>> The patch also adds a simple ASoC PCM driver for the PL330 DMA controller using
>> the generic dmaengine PCM driver. This driver is only temporary can be removed
>> once we have all the infrastructure in place to query information like maximum
>> transfer size directly from the dmaengine driver.
> 
> It's not really a driver as such, it's just specifying some extra
> parameters - I'd expect you're going to need to keep the addresses at
> least.  It's probably more accurate to say that at the minute there's
> some assumptions in the driver about the DMA controller configuration
> that will be required which should be removable in future?

Sorry, I forgot to update that paragraph there used to be a separate PCM
driver, but it's now all handled by generic PCM driver since it is now able
to query the constraints from the DMA driver.

> 
>> +config SND_SOC_ADI
>> +	tristate "Audio support for Analog Devices reference designs"
>> +	depends on SND_SOC && (MICROBLAZE || ARCH_ZYNQ || COMPILE_TEST)
>> +	help
>> +	  Audio support for various reference designs by Analog Devices.
>> +
> 
> Given that this is a FPGA IP I'd also expect it to be available on
> SOCFPGA and probably other things.  For the Designware I2S controller we
> just don't have any platform dependency at all.

We only use it on ZYNQ and Microblaze though. And people have complained in
the past about symbols that are viable on their platform, but are not
relevant for their platform. And to use the core on a different FPGA
platform will most likely require changes to the core, unless the other FPGA
also has a PL330 DMA interface. So I'd prefer to only make it avaiable on
ZYNQ and Microblaze right now.

> 
> There's no need for the SND_SOC dependency, all the subdirectory
> Kconfigs are only included in an if SND_SOC block.
> 
>> +	frame_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;
> 
> This isn't obvious - usually the frame size is the number of bits per
> frame.  Looking at the code I guess the hardware is more flexible than
> the driver allows at the minute?

The core allows to configure the bitclock cycles per word. Right now the
frame size is just hardcoded to 64. It's probably something that could be
made configurable by snd_soc_dai_set_bclk_ratio(). But we really don't need
that feature at the moment. But I'll add a comment explaining this. And
maybe rename the variable from framesize to wordsize.

Thanks for the quick review.

I'll wait for comments on the DT bindings and send out a v2 probably at the
end of next week.

- Lars

Re: [PATCH 2/4] ASoC: Add support for the Analog Devices AXI-I2S core

[Mark Brown]

[-- Attachment #1.1: Type: text/plain, Size: 1014 bytes --]

On Fri, Nov 29, 2013 at 02:04:48PM +0100, Lars-Peter Clausen wrote:

> We only use it on ZYNQ and Microblaze though. And people have complained in
> the past about symbols that are viable on their platform, but are not
> relevant for their platform. And to use the core on a different FPGA
> platform will most likely require changes to the core, unless the other FPGA
> also has a PL330 DMA interface. So I'd prefer to only make it avaiable on
> ZYNQ and Microblaze right now.

Is it really restricted to PL330 at the hardware level?  I don't recall
anything too fancy in the datasheet there.

> >> +	frame_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;

> > This isn't obvious - usually the frame size is the number of bits per
> > frame.  Looking at the code I guess the hardware is more flexible than
> > the driver allows at the minute?

> that feature at the moment. But I'll add a comment explaining this. And
> maybe rename the variable from framesize to wordsize.

It definitely needs to be changed to word size.

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Re: [PATCH 2/4] ASoC: Add support for the Analog Devices AXI-I2S core

[Lars-Peter Clausen]

On 11/29/2013 03:27 PM, Mark Brown wrote:
> On Fri, Nov 29, 2013 at 02:04:48PM +0100, Lars-Peter Clausen wrote:
> 
>> We only use it on ZYNQ and Microblaze though. And people have complained in
>> the past about symbols that are viable on their platform, but are not
>> relevant for their platform. And to use the core on a different FPGA
>> platform will most likely require changes to the core, unless the other FPGA
>> also has a PL330 DMA interface. So I'd prefer to only make it avaiable on
>> ZYNQ and Microblaze right now.
> 
> Is it really restricted to PL330 at the hardware level?  I don't recall
> anything too fancy in the datasheet there.

Yes, it is using the PL330 peripheral request interface.  See
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0424a/index.html
and
https://github.com/analogdevicesinc/fpgahdl_xilinx/blob/master/cf_lib/edk/pcores/adi_common_v1_00_a/hdl/vhdl/pl330_dma_fifo.vhd

- Lars

[PATCH 3/4] dt: Add bindings documentation for the ADI AXI-SPDIF audio controller

[Lars-Peter Clausen]

This patch adds the devicetree documentation for the ADI AXI-SPDIF audio
controller. The controller has:
 * One set of memory mapped register
 * Two clocks, one for the memory mapped register interface, one used as the
   audio reference clock
 * A DMA interface for the transmit data

Signed-off-by: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
Cc: Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Cc: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
Cc: Ian Campbell <ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 .../devicetree/bindings/sound/adi,axi-spdif-tx.txt | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt

diff --git a/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt b/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt
new file mode 100644
index 0000000..489ba9be
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt
@@ -0,0 +1,29 @@
+ADI AXI-SPDIF controller
+
+Required properties:
+ - compatible : Must be "adi,axi-spdif-1.00.a"
+ - reg : Must contain SPDIF registers location and length
+ - clocks : Clock specifier providing a handle to the controller's clocks. The
+   controller expects two clocks, the clock used for the AXI interface and the
+   clock used as the sample rate reference clock.
+ - clock-names: "axi" for the clock to the AXI interface, "ref" for the sample
+   rate reference clock.
+ - dma : Phandle to the dma channels for the transmit DMA.
+ - dma-names : Must be "tx"
+
+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:
+
+	spdif: spdif@0x77400000 {
+		compatible = "adi,axi-spdif-tx-1.00.a";
+		reg = <0x77600000 0x1000>;
+		clocks = <&clk 15 &audio_clock>;
+		clock-names = "axi", "ref";
+		dmas = <&ps7_dma 0>;
+		dma-names = "tx";
+	};
-- 
1.8.0

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[PATCH 4/4] ASoC: Add support for the Analog Devices AXI-SPDIF driver

[Lars-Peter Clausen]

This patch adds a ASoC driver for the AXI-SPDIF core. The core implements a
simple SPDIF transmitter and is used on some Analog Devices' reference designs
for various FPGA platforms. For now the driver only support the PL330 as the the
DMA controller.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
Has a compile time dependency on topic/dma
---
 sound/soc/adi/Kconfig     |   8 ++
 sound/soc/adi/Makefile    |   2 +
 sound/soc/adi/axi-spdif.c | 272 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 282 insertions(+)
 create mode 100644 sound/soc/adi/axi-spdif.c

diff --git a/sound/soc/adi/Kconfig b/sound/soc/adi/Kconfig
index 14bb385..82438de 100644
--- a/sound/soc/adi/Kconfig
+++ b/sound/soc/adi/Kconfig
@@ -11,3 +11,11 @@ config SND_SOC_ADI_AXI_I2S
 	select REGMAP_MMIO
 	help
 	  ASoC driver for the Analog Devices AXI-I2S softcore peripheral.
+
+config SND_SOC_ADI_AXI_SPDIF
+	tristate "AXI-SPDIF support"
+	depends on SND_SOC_ADI
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  ASoC driver for the Analog Devices AXI-SPDIF softcore peripheral.
diff --git a/sound/soc/adi/Makefile b/sound/soc/adi/Makefile
index d32c21a..64456c1 100644
--- a/sound/soc/adi/Makefile
+++ b/sound/soc/adi/Makefile
@@ -1,3 +1,5 @@
 snd-soc-adi-axi-i2s-objs := axi-i2s.o
+snd-soc-adi-axi-spdif-objs := axi-spdif.o
 
 obj-$(CONFIG_SND_SOC_ADI_AXI_I2S) += snd-soc-adi-axi-i2s.o
+obj-$(CONFIG_SND_SOC_ADI_AXI_SPDIF) += snd-soc-adi-axi-spdif.o
diff --git a/sound/soc/adi/axi-spdif.c b/sound/soc/adi/axi-spdif.c
new file mode 100644
index 0000000..806fc8f
--- /dev/null
+++ b/sound/soc/adi/axi-spdif.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2012-2013, Analog Devices Inc.
+ * Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <sound/dmaengine_pcm.h>
+
+#define AXI_SPDIF_REG_CTRL	0x0
+#define AXI_SPDIF_REG_STAT	0x4
+#define AXI_SPDIF_REG_TX_FIFO	0xc
+
+#define AXI_SPDIF_CTRL_TXDATA BIT(1)
+#define AXI_SPDIF_CTRL_TXEN BIT(0)
+#define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
+#define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
+
+#define AXI_SPDIF_FREQ_44100	(0x0 << 6)
+#define AXI_SPDIF_FREQ_48000	(0x1 << 6)
+#define AXI_SPDIF_FREQ_32000	(0x2 << 6)
+#define AXI_SPDIF_FREQ_NA	(0x3 << 6)
+
+struct axi_spdif {
+	struct regmap *regmap;
+	struct clk *clk;
+	struct clk *clk_ref;
+
+	struct snd_dmaengine_dai_dma_data dma_data;
+
+	struct snd_ratnum ratnum;
+	struct snd_pcm_hw_constraint_ratnums rate_constraints;
+};
+
+static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
+	struct snd_soc_dai *dai)
+{
+	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+	unsigned int val;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		val = AXI_SPDIF_CTRL_TXDATA;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+		AXI_SPDIF_CTRL_TXDATA, val);
+
+	return 0;
+}
+
+static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
+{
+	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+	unsigned int rate = params_rate(params);
+	unsigned int clkdiv, stat;
+
+	switch (params_rate(params)) {
+	case 32000:
+		stat = AXI_SPDIF_FREQ_32000;
+		break;
+	case 44100:
+		stat = AXI_SPDIF_FREQ_44100;
+		break;
+	case 48000:
+		stat = AXI_SPDIF_FREQ_48000;
+		break;
+	default:
+		stat = AXI_SPDIF_FREQ_NA;
+		break;
+	}
+
+	clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
+			rate * 64 * 2) - 1;
+	clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
+
+	regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
+	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+		AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
+
+	return 0;
+}
+
+static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
+{
+	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
+
+	return 0;
+}
+
+static int axi_spdif_startup(struct snd_pcm_substream *substream,
+	struct snd_soc_dai *dai)
+{
+	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
+			   SNDRV_PCM_HW_PARAM_RATE,
+			   &spdif->rate_constraints);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(spdif->clk_ref);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+		AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
+
+	return 0;
+}
+
+static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
+	struct snd_soc_dai *dai)
+{
+	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+
+	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+		AXI_SPDIF_CTRL_TXEN, 0);
+
+	clk_disable_unprepare(spdif->clk_ref);
+}
+
+static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
+	.startup = axi_spdif_startup,
+	.shutdown = axi_spdif_shutdown,
+	.trigger = axi_spdif_trigger,
+	.hw_params = axi_spdif_hw_params,
+};
+
+static struct snd_soc_dai_driver axi_spdif_dai = {
+	.probe = axi_spdif_dai_probe,
+	.playback = {
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_KNOT,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	},
+	.ops = &axi_spdif_dai_ops,
+};
+
+static const struct snd_soc_component_driver axi_spdif_component = {
+	.name		= "axi-spdif",
+};
+
+static const struct regmap_config axi_spdif_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = AXI_SPDIF_REG_STAT,
+};
+
+static int axi_spdif_probe(struct platform_device *pdev)
+{
+	struct axi_spdif *spdif;
+	struct resource *res;
+	void __iomem *base;
+	int ret;
+
+	spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
+	if (!spdif)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, spdif);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!base)
+		return -EBUSY;
+
+	spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					    &axi_spdif_regmap_config);
+	if (IS_ERR(spdif->regmap))
+		return PTR_ERR(spdif->regmap);
+
+	spdif->clk = devm_clk_get(&pdev->dev, "axi");
+	if (IS_ERR(spdif->clk))
+		return PTR_ERR(spdif->clk);
+
+	spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
+	if (IS_ERR(spdif->clk_ref))
+		return PTR_ERR(spdif->clk_ref);
+
+	ret = clk_prepare_enable(spdif->clk);
+	if (ret)
+		return ret;
+
+	spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
+	spdif->dma_data.addr_width = 4;
+	spdif->dma_data.maxburst = 1;
+
+	spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
+	spdif->ratnum.den_step = 1;
+	spdif->ratnum.den_min = 1;
+	spdif->ratnum.den_max = 64;
+
+	spdif->rate_constraints.rats = &spdif->ratnum;
+	spdif->rate_constraints.nrats = 1;
+
+	ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
+					 &axi_spdif_dai, 1);
+	if (ret)
+		goto err_clk_disable;
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL,
+			SND_DMAENGINE_PCM_FLAG_NO_RESIDUE);
+	if (ret)
+		goto err_clk_disable;
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(spdif->clk);
+	return ret;
+}
+
+static int axi_spdif_dev_remove(struct platform_device *pdev)
+{
+	struct axi_spdif *spdif = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(spdif->clk);
+
+	return 0;
+}
+
+static const struct of_device_id axi_spdif_of_match[] = {
+	{ .compatible = "adi,axi-spdif-tx-1.00.a", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
+
+static struct platform_driver axi_spdif_driver = {
+	.driver = {
+		.name = "axi-spdif",
+		.owner = THIS_MODULE,
+		.of_match_table = axi_spdif_of_match,
+	},
+	.probe = axi_spdif_probe,
+	.remove = axi_spdif_dev_remove,
+};
+module_platform_driver(axi_spdif_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("AXI SPDIF driver");
+MODULE_LICENSE("GPL");
-- 
1.8.0

Re: [PATCH 4/4] ASoC: Add support for the Analog Devices AXI-SPDIF driver

[Mark Brown]

[-- Attachment #1.1: Type: text/plain, Size: 459 bytes --]

On Thu, Nov 28, 2013 at 08:02:52PM +0100, Lars-Peter Clausen wrote:
> This patch adds a ASoC driver for the AXI-SPDIF core. The core implements a
> simple SPDIF transmitter and is used on some Analog Devices' reference designs
> for various FPGA platforms. For now the driver only support the PL330 as the the
> DMA controller.

Similar comments to the I2S driver here.  I'd probably apply them but
I'm holding off in case there is review of the DT bindings.

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