#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 = {
.probe = axi_spdif_dai_probe,
.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 = {
.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",
.legacy_dai_naming = 1,
};
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);
base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(base))
return PTR_ERR(base);
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, 0);
if (ret)
goto err_clk_disable;
return 0;
err_clk_disable:
clk_disable_unprepare(spdif->clk);
return ret;
}
static void axi_spdif_dev_remove(struct platform_device *pdev)
{
struct axi_spdif *spdif = platform_get_drvdata(pdev);
clk_disable_unprepare(spdif->clk);
}
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",
.of_match_table = axi_spdif_of_match,
},
.probe = axi_spdif_probe,
.remove_new = 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"