xlnx_i2s.c

// SPDX-License-Identifier: GPL-2.0
//
// Xilinx ASoC I2S audio support
//
// Copyright (C) 2018 Xilinx, Inc.
//
// Author: Praveen Vuppala <praveenv@xilinx.com>
// Author: Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>

#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#define DRV_NAME "xlnx_i2s"

#define I2S_CORE_CTRL_OFFSET		0x08
#define I2S_CORE_CTRL_32BIT_LRCLK	BIT(3)
#define I2S_CORE_CTRL_ENABLE		BIT(0)
#define I2S_I2STIM_OFFSET		0x20
#define I2S_CH0_OFFSET			0x30
#define I2S_I2STIM_VALID_MASK		GENMASK(7, 0)

struct xlnx_i2s_drv_data {
	struct snd_soc_dai_driver dai_drv;
	void __iomem *base;
	unsigned int sysclk;
	u32 data_width;
	u32 channels;
	bool is_32bit_lrclk;
	struct snd_ratnum ratnum;
	struct snd_pcm_hw_constraint_ratnums rate_constraints;
};

static int xlnx_i2s_set_sclkout_div(struct snd_soc_dai *cpu_dai,
				    int div_id, int div)
{
	struct xlnx_i2s_drv_data *drv_data = snd_soc_dai_get_drvdata(cpu_dai);

	if (!div || (div & ~I2S_I2STIM_VALID_MASK))
		return -EINVAL;

	drv_data->sysclk = 0;

	writel(div, drv_data->base + I2S_I2STIM_OFFSET);

	return 0;
}

static int xlnx_i2s_set_sysclk(struct snd_soc_dai *dai,
			       int clk_id, unsigned int freq, int dir)
{
	struct xlnx_i2s_drv_data *drv_data = snd_soc_dai_get_drvdata(dai);

	drv_data->sysclk = freq;
	if (freq) {
		unsigned int bits_per_sample;

		if (drv_data->is_32bit_lrclk)
			bits_per_sample = 32;
		else
			bits_per_sample = drv_data->data_width;

		drv_data->ratnum.num = freq / (bits_per_sample * drv_data->channels) / 2;
		drv_data->ratnum.den_step = 1;
		drv_data->ratnum.den_min = 1;
		drv_data->ratnum.den_max = 255;
		drv_data->rate_constraints.rats = &drv_data->ratnum;
		drv_data->rate_constraints.nrats = 1;
	}
	return 0;
}

static int xlnx_i2s_startup(struct snd_pcm_substream *substream,
			    struct snd_soc_dai *dai)
{
	struct xlnx_i2s_drv_data *drv_data = snd_soc_dai_get_drvdata(dai);

	if (drv_data->sysclk)
		return snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
						     SNDRV_PCM_HW_PARAM_RATE,
						     &drv_data->rate_constraints);

	return 0;
}

static int xlnx_i2s_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *params,
			      struct snd_soc_dai *i2s_dai)
{
	u32 reg_off, chan_id;
	struct xlnx_i2s_drv_data *drv_data = snd_soc_dai_get_drvdata(i2s_dai);

	if (drv_data->sysclk) {
		unsigned int bits_per_sample, sclk, sclk_div;

		if (drv_data->is_32bit_lrclk)
			bits_per_sample = 32;
		else
			bits_per_sample = drv_data->data_width;

		sclk = params_rate(params) * bits_per_sample * params_channels(params);
		sclk_div = drv_data->sysclk / sclk / 2;

		if ((drv_data->sysclk % sclk != 0) ||
		    !sclk_div || (sclk_div & ~I2S_I2STIM_VALID_MASK)) {
			dev_warn(i2s_dai->dev, "invalid SCLK divisor for sysclk %u and sclk %u\n",
				 drv_data->sysclk, sclk);
			return -EINVAL;
		}
		writel(sclk_div, drv_data->base + I2S_I2STIM_OFFSET);
	}

	chan_id = params_channels(params) / 2;

	while (chan_id > 0) {
		reg_off = I2S_CH0_OFFSET + ((chan_id - 1) * 4);
		writel(chan_id, drv_data->base + reg_off);
		chan_id--;
	}

	return 0;
}

static int xlnx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
			    struct snd_soc_dai *i2s_dai)
{
	struct xlnx_i2s_drv_data *drv_data = snd_soc_dai_get_drvdata(i2s_dai);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		writel(I2S_CORE_CTRL_ENABLE, drv_data->base + I2S_CORE_CTRL_OFFSET);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		writel(0, drv_data->base + I2S_CORE_CTRL_OFFSET);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static const struct snd_soc_dai_ops xlnx_i2s_dai_ops = {
	.trigger = xlnx_i2s_trigger,
	.set_sysclk = xlnx_i2s_set_sysclk,
	.set_clkdiv = xlnx_i2s_set_sclkout_div,
	.startup = xlnx_i2s_startup,
	.hw_params = xlnx_i2s_hw_params
};

static const struct snd_soc_component_driver xlnx_i2s_component = {
	.name = DRV_NAME,
	.legacy_dai_naming = 1,
};

static const struct of_device_id xlnx_i2s_of_match[] = {
	{ .compatible = "xlnx,i2s-transmitter-1.0", },
	{ .compatible = "xlnx,i2s-receiver-1.0", },
	{},
};
MODULE_DEVICE_TABLE(of, xlnx_i2s_of_match);

static int xlnx_i2s_probe(struct platform_device *pdev)
{
	struct xlnx_i2s_drv_data *drv_data;
	int ret;
	u32 format;
	struct device *dev = &pdev->dev;
	struct device_node *node = dev->of_node;

	drv_data = devm_kzalloc(&pdev->dev, sizeof(*drv_data), GFP_KERNEL);
	if (!drv_data)
		return -ENOMEM;

	drv_data->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(drv_data->base))
		return PTR_ERR(drv_data->base);

	ret = of_property_read_u32(node, "xlnx,num-channels", &drv_data->channels);
	if (ret < 0) {
		dev_err(dev, "cannot get supported channels\n");
		return ret;
	}
	drv_data->channels *= 2;

	ret = of_property_read_u32(node, "xlnx,dwidth", &drv_data->data_width);
	if (ret < 0) {
		dev_err(dev, "cannot get data width\n");
		return ret;
	}
	switch (drv_data->data_width) {
	case 16:
		format = SNDRV_PCM_FMTBIT_S16_LE;
		break;
	case 24:
		format = SNDRV_PCM_FMTBIT_S24_LE;
		break;
	default:
		return -EINVAL;
	}

	if (of_device_is_compatible(node, "xlnx,i2s-transmitter-1.0")) {
		drv_data->dai_drv.name = "xlnx_i2s_playback";
		drv_data->dai_drv.playback.stream_name = "Playback";
		drv_data->dai_drv.playback.formats = format;
		drv_data->dai_drv.playback.channels_min = drv_data->channels;
		drv_data->dai_drv.playback.channels_max = drv_data->channels;
		drv_data->dai_drv.playback.rates	= SNDRV_PCM_RATE_8000_192000;
		drv_data->dai_drv.ops = &xlnx_i2s_dai_ops;
	} else if (of_device_is_compatible(node, "xlnx,i2s-receiver-1.0")) {
		drv_data->dai_drv.name = "xlnx_i2s_capture";
		drv_data->dai_drv.capture.stream_name = "Capture";
		drv_data->dai_drv.capture.formats = format;
		drv_data->dai_drv.capture.channels_min = drv_data->channels;
		drv_data->dai_drv.capture.channels_max = drv_data->channels;
		drv_data->dai_drv.capture.rates = SNDRV_PCM_RATE_8000_192000;
		drv_data->dai_drv.ops = &xlnx_i2s_dai_ops;
	} else {
		return -ENODEV;
	}
	drv_data->is_32bit_lrclk = readl(drv_data->base + I2S_CORE_CTRL_OFFSET) &
				   I2S_CORE_CTRL_32BIT_LRCLK;

	dev_set_drvdata(&pdev->dev, drv_data);

	ret = devm_snd_soc_register_component(&pdev->dev, &xlnx_i2s_component,
					      &drv_data->dai_drv, 1);
	if (ret) {
		dev_err(&pdev->dev, "i2s component registration failed\n");
		return ret;
	}

	dev_info(&pdev->dev, "%s DAI registered\n", drv_data->dai_drv.name);

	return ret;
}

static struct platform_driver xlnx_i2s_aud_driver = {
	.driver = {
		.name = DRV_NAME,
		.of_match_table = xlnx_i2s_of_match,
	},
	.probe = xlnx_i2s_probe,
};

module_platform_driver(xlnx_i2s_aud_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Praveen Vuppala  <praveenv@xilinx.com>");
MODULE_AUTHOR("Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>");