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/*
* 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)
/* The frame size is configurable, but for now we always set it 64 bit */
#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, word_size;
unsigned int bclk_rate;
bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME;
word_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, (word_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_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
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");
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