// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/sound/soc/ep93xx-i2s.c
* EP93xx I2S driver
*
* Copyright (C) 2010 Ryan Mallon
*
* Based on the original driver by:
* Copyright (C) 2007 Chase Douglas <chasedouglas@gmail>
* Copyright (C) 2006 Lennert Buytenhek <[email protected]>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of.h>
#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <linux/soc/cirrus/ep93xx.h>
#include "ep93xx-pcm.h"
#define EP93XX_I2S_TXCLKCFG 0x00
#define EP93XX_I2S_RXCLKCFG 0x04
#define EP93XX_I2S_GLSTS 0x08
#define EP93XX_I2S_GLCTRL 0x0C
#define EP93XX_I2S_I2STX0LFT 0x10
#define EP93XX_I2S_I2STX0RT 0x14
#define EP93XX_I2S_TXLINCTRLDATA 0x28
#define EP93XX_I2S_TXCTRL 0x2C
#define EP93XX_I2S_TXWRDLEN 0x30
#define EP93XX_I2S_TX0EN 0x34
#define EP93XX_I2S_RXLINCTRLDATA 0x58
#define EP93XX_I2S_RXCTRL 0x5C
#define EP93XX_I2S_RXWRDLEN 0x60
#define EP93XX_I2S_RX0EN 0x64
#define EP93XX_I2S_WRDLEN_16 (0 << 0)
#define EP93XX_I2S_WRDLEN_24 (1 << 0)
#define EP93XX_I2S_WRDLEN_32 (2 << 0)
#define EP93XX_I2S_RXLINCTRLDATA_R_JUST BIT(1) /* Right justify */
#define EP93XX_I2S_TXLINCTRLDATA_R_JUST BIT(2) /* Right justify */
/*
* Transmit empty interrupt level select:
* 0 - Generate interrupt when FIFO is half empty
* 1 - Generate interrupt when FIFO is empty
*/
#define EP93XX_I2S_TXCTRL_TXEMPTY_LVL BIT(0)
#define EP93XX_I2S_TXCTRL_TXUFIE BIT(1) /* Transmit interrupt enable */
#define EP93XX_I2S_CLKCFG_LRS (1 << 0) /* lrclk polarity */
#define EP93XX_I2S_CLKCFG_CKP (1 << 1) /* Bit clock polarity */
#define EP93XX_I2S_CLKCFG_REL (1 << 2) /* First bit transition */
#define EP93XX_I2S_CLKCFG_MASTER (1 << 3) /* Master mode */
#define EP93XX_I2S_CLKCFG_NBCG (1 << 4) /* Not bit clock gating */
#define EP93XX_I2S_GLSTS_TX0_FIFO_FULL BIT(12)
struct ep93xx_i2s_info {
struct clk *mclk;
struct clk *sclk;
struct clk *lrclk;
void __iomem *regs;
struct snd_dmaengine_dai_dma_data dma_params_rx;
struct snd_dmaengine_dai_dma_data dma_params_tx;
};
static inline void ep93xx_i2s_write_reg(struct ep93xx_i2s_info *info,
unsigned reg, unsigned val)
{
__raw_writel(val, info->regs + reg);
}
static inline unsigned ep93xx_i2s_read_reg(struct ep93xx_i2s_info *info,
unsigned reg)
{
return __raw_readl(info->regs + reg);
}
static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
{
unsigned base_reg;
if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
(ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
/* Enable clocks */
clk_prepare_enable(info->mclk);
clk_prepare_enable(info->sclk);
clk_prepare_enable(info->lrclk);
/* Enable i2s */
ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 1);
}
/* Enable fifo */
if (stream == SNDRV_PCM_STREAM_PLAYBACK)
base_reg = EP93XX_I2S_TX0EN;
else
base_reg = EP93XX_I2S_RX0EN;
ep93xx_i2s_write_reg(info, base_reg, 1);
/* Enable TX IRQs (FIFO empty or underflow) */
if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
stream == SNDRV_PCM_STREAM_PLAYBACK)
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL,
EP93XX_I2S_TXCTRL_TXEMPTY_LVL |
EP93XX_I2S_TXCTRL_TXUFIE);
}
static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
{
unsigned base_reg;
/* Disable IRQs */
if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG) &&
stream == SNDRV_PCM_STREAM_PLAYBACK)
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCTRL, 0);
/* Disable fifo */
if (stream == SNDRV_PCM_STREAM_PLAYBACK)
base_reg = EP93XX_I2S_TX0EN;
else
base_reg = EP93XX_I2S_RX0EN;
ep93xx_i2s_write_reg(info, base_reg, 0);
if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
(ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
/* Disable i2s */
ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 0);
/* Disable clocks */
clk_disable_unprepare(info->lrclk);
clk_disable_unprepare(info->sclk);
clk_disable_unprepare(info->mclk);
}
}
/*
* According to documentation I2S controller can handle underflow conditions
* just fine, but in reality the state machine is sometimes confused so that
* the whole stream is shifted by one byte. The watchdog below disables the TX
* FIFO, fills the buffer with zeroes and re-enables the FIFO. State machine
* is being reset and by filling the buffer we get some time before next
* underflow happens.
*/
static irqreturn_t ep93xx_i2s_interrupt(int irq, void *dev_id)
{
struct ep93xx_i2s_info *info = dev_id;
/* Disable FIFO */
ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 0);
/*
* Fill TX FIFO with zeroes, this way we can defer next IRQs as much as
* possible and get more time for DMA to catch up. Actually there are
* only 8 samples in this FIFO, so even on 8kHz maximum deferral here is
* 1ms.
*/
while (!(ep93xx_i2s_read_reg(info, EP93XX_I2S_GLSTS) &
EP93XX_I2S_GLSTS_TX0_FIFO_FULL)) {
ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0LFT, 0);
ep93xx_i2s_write_reg(info, EP93XX_I2S_I2STX0RT, 0);
}
/* Re-enable FIFO */
ep93xx_i2s_write_reg(info, EP93XX_I2S_TX0EN, 1);
return IRQ_HANDLED;
}
static int ep93xx_i2s_dai_probe(struct snd_soc_dai *dai)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
snd_soc_dai_init_dma_data(dai, &info->dma_params_tx,
&info->dma_params_rx);
return 0;
}
static int ep93xx_i2s_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
ep93xx_i2s_enable(info, substream->stream);
return 0;
}
static void ep93xx_i2s_shutdown(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
ep93xx_i2s_disable(info, substream->stream);
}
static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
unsigned int fmt)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
unsigned int clk_cfg;
unsigned int txlin_ctrl = 0;
unsigned int rxlin_ctrl = 0;
clk_cfg = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXCLKCFG);
switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
clk_cfg |= EP93XX_I2S_CLKCFG_REL;
break;
case SND_SOC_DAIFMT_LEFT_J:
clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
break;
case SND_SOC_DAIFMT_RIGHT_J:
clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
rxlin_ctrl |= EP93XX_I2S_RXLINCTRLDATA_R_JUST;
txlin_ctrl |= EP93XX_I2S_TXLINCTRLDATA_R_JUST;
break;
default:
return -EINVAL;
}
switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
case SND_SOC_DAIFMT_BP_FP:
/* CPU is provider */
clk_cfg |= EP93XX_I2S_CLKCFG_MASTER;
break;
case SND_SOC_DAIFMT_BC_FC:
/* Codec is provider */
clk_cfg &= ~EP93XX_I2S_CLKCFG_MASTER;
break;
default:
return -EINVAL;
}
switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
case SND_SOC_DAIFMT_NB_NF:
/* Negative bit clock, lrclk low on left word */
clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS);
break;
case SND_SOC_DAIFMT_NB_IF:
/* Negative bit clock, lrclk low on right word */
clk_cfg &= ~EP93XX_I2S_CLKCFG_CKP;
clk_cfg |= EP93XX_I2S_CLKCFG_LRS;
break;
case SND_SOC_DAIFMT_IB_NF:
/* Positive bit clock, lrclk low on left word */
clk_cfg |= EP93XX_I2S_CLKCFG_CKP;
clk_cfg &= ~EP93XX_I2S_CLKCFG_LRS;
break;
case SND_SOC_DAIFMT_IB_IF:
/* Positive bit clock, lrclk low on right word */
clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_LRS;
break;
}
/* Write new register values */
ep93xx_i2s_write_reg(info, EP93XX_I2S_RXCLKCFG, clk_cfg);
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCLKCFG, clk_cfg);
ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, rxlin_ctrl);
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, txlin_ctrl);
return 0;
}
static int ep93xx_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *dai)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
unsigned word_len, div, sdiv, lrdiv;
int err;
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE:
word_len = EP93XX_I2S_WRDLEN_16;
break;
case SNDRV_PCM_FORMAT_S24_LE:
word_len = EP93XX_I2S_WRDLEN_24;
break;
case SNDRV_PCM_FORMAT_S32_LE:
word_len = EP93XX_I2S_WRDLEN_32;
break;
default:
return -EINVAL;
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
ep93xx_i2s_write_reg(info, EP93XX_I2S_TXWRDLEN, word_len);
else
ep93xx_i2s_write_reg(info, EP93XX_I2S_RXWRDLEN, word_len);
/*
* EP93xx I2S module can be setup so SCLK / LRCLK value can be
* 32, 64, 128. MCLK / SCLK value can be 2 and 4.
* We set LRCLK equal to `rate' and minimum SCLK / LRCLK
* value is 64, because our sample size is 32 bit * 2 channels.
* I2S standard permits us to transmit more bits than
* the codec uses.
*/
div = clk_get_rate(info->mclk) / params_rate(params);
sdiv = 4;
if (div > (256 + 512) / 2) {
lrdiv = 128;
} else {
lrdiv = 64;
if (div < (128 + 256) / 2)
sdiv = 2;
}
err = clk_set_rate(info->sclk, clk_get_rate(info->mclk) / sdiv);
if (err)
return err;
err = clk_set_rate(info->lrclk, clk_get_rate(info->sclk) / lrdiv);
if (err)
return err;
return 0;
}
static int ep93xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
unsigned int freq, int dir)
{
struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
if (dir == SND_SOC_CLOCK_IN || clk_id != 0)
return -EINVAL;
if (!freq)
return 0;
return clk_set_rate(info->mclk, freq);
}
#ifdef CONFIG_PM
static int ep93xx_i2s_suspend(struct snd_soc_component *component)
{
struct ep93xx_i2s_info *info = snd_soc_component_get_drvdata(component);
if (!snd_soc_component_active(component))
return 0;
ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_PLAYBACK);
ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_CAPTURE);
return 0;
}
static int ep93xx_i2s_resume(struct snd_soc_component *component)
{
struct ep93xx_i2s_info *info = snd_soc_component_get_drvdata(component);
if (!snd_soc_component_active(component))
return 0;
ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_PLAYBACK);
ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_CAPTURE);
return 0;
}
#else
#define ep93xx_i2s_suspend NULL
#define ep93xx_i2s_resume NULL
#endif
static const struct snd_soc_dai_ops ep93xx_i2s_dai_ops = {
.probe = ep93xx_i2s_dai_probe,
.startup = ep93xx_i2s_startup,
.shutdown = ep93xx_i2s_shutdown,
.hw_params = ep93xx_i2s_hw_params,
.set_sysclk = ep93xx_i2s_set_sysclk,
.set_fmt = ep93xx_i2s_set_dai_fmt,
};
#define EP93XX_I2S_FORMATS (SNDRV_PCM_FMTBIT_S32_LE)
static struct snd_soc_dai_driver ep93xx_i2s_dai = {
.symmetric_rate = 1,
.playback = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = EP93XX_I2S_FORMATS,
},
.capture = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = EP93XX_I2S_FORMATS,
},
.ops = &ep93xx_i2s_dai_ops,
};
static const struct snd_soc_component_driver ep93xx_i2s_component = {
.name = "ep93xx-i2s",
.suspend = ep93xx_i2s_suspend,
.resume = ep93xx_i2s_resume,
.legacy_dai_naming = 1,
};
static int ep93xx_i2s_probe(struct platform_device *pdev)
{
struct ep93xx_i2s_info *info;
int err;
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(info->regs))
return PTR_ERR(info->regs);
if (IS_ENABLED(CONFIG_SND_EP93XX_SOC_I2S_WATCHDOG)) {
int irq = platform_get_irq(pdev, 0);
if (irq <= 0)
return irq < 0 ? irq : -ENODEV;
err = devm_request_irq(&pdev->dev, irq, ep93xx_i2s_interrupt, 0,
pdev->name, info);
if (err)
return err;
}
info->mclk = clk_get(&pdev->dev, "mclk");
if (IS_ERR(info->mclk)) {
err = PTR_ERR(info->mclk);
goto fail;
}
info->sclk = clk_get(&pdev->dev, "sclk");
if (IS_ERR(info->sclk)) {
err = PTR_ERR(info->sclk);
goto fail_put_mclk;
}
info->lrclk = clk_get(&pdev->dev, "lrclk");
if (IS_ERR(info->lrclk)) {
err = PTR_ERR(info->lrclk);
goto fail_put_sclk;
}
dev_set_drvdata(&pdev->dev, info);
err = devm_snd_soc_register_component(&pdev->dev, &ep93xx_i2s_component,
&ep93xx_i2s_dai, 1);
if (err)
goto fail_put_lrclk;
err = devm_ep93xx_pcm_platform_register(&pdev->dev);
if (err)
goto fail_put_lrclk;
return 0;
fail_put_lrclk:
clk_put(info->lrclk);
fail_put_sclk:
clk_put(info->sclk);
fail_put_mclk:
clk_put(info->mclk);
fail:
return err;
}
static void ep93xx_i2s_remove(struct platform_device *pdev)
{
struct ep93xx_i2s_info *info = dev_get_drvdata(&pdev->dev);
clk_put(info->lrclk);
clk_put(info->sclk);
clk_put(info->mclk);
}
static const struct of_device_id ep93xx_i2s_of_ids[] = {
{ .compatible = "cirrus,ep9301-i2s" },
{}
};
MODULE_DEVICE_TABLE(of, ep93xx_i2s_of_ids);
static struct platform_driver ep93xx_i2s_driver = {
.probe = ep93xx_i2s_probe,
.remove = ep93xx_i2s_remove,
.driver = {
.name = "ep93xx-i2s",
.of_match_table = ep93xx_i2s_of_ids,
},
};
module_platform_driver(ep93xx_i2s_driver);
MODULE_ALIAS("platform:ep93xx-i2s");
MODULE_AUTHOR("Ryan Mallon");
MODULE_DESCRIPTION("EP93XX I2S driver");
MODULE_LICENSE("GPL");
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