- 根目录:
- sound
- soc
- bcm
- bcm2835-i2s.c
/*
* ALSA SoC I2S Audio Layer for Broadcom BCM2835 SoC
*
* Author: Florian Meier <florian.meier@koalo.de>
* Copyright 2013
*
* Based on
* Raspberry Pi PCM I2S ALSA Driver
* Copyright (c) by Phil Poole 2013
*
* ALSA SoC I2S (McBSP) Audio Layer for TI DAVINCI processor
* Vladimir Barinov, <vbarinov@embeddedalley.com>
* Copyright (C) 2007 MontaVista Software, Inc., <source@mvista.com>
*
* OMAP ALSA SoC DAI driver using McBSP port
* Copyright (C) 2008 Nokia Corporation
* Contact: Jarkko Nikula <jarkko.nikula@bitmer.com>
* Peter Ujfalusi <peter.ujfalusi@ti.com>
*
* Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
* Author: Timur Tabi <timur@freescale.com>
* Copyright 2007-2010 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
/* Clock registers */
#define BCM2835_CLK_PCMCTL_REG 0x00
#define BCM2835_CLK_PCMDIV_REG 0x04
/* Clock register settings */
#define BCM2835_CLK_PASSWD (0x5a000000)
#define BCM2835_CLK_PASSWD_MASK (0xff000000)
#define BCM2835_CLK_MASH(v) ((v) << 9)
#define BCM2835_CLK_FLIP BIT(8)
#define BCM2835_CLK_BUSY BIT(7)
#define BCM2835_CLK_KILL BIT(5)
#define BCM2835_CLK_ENAB BIT(4)
#define BCM2835_CLK_SRC(v) (v)
#define BCM2835_CLK_SHIFT (12)
#define BCM2835_CLK_DIVI(v) ((v) << BCM2835_CLK_SHIFT)
#define BCM2835_CLK_DIVF(v) (v)
#define BCM2835_CLK_DIVF_MASK (0xFFF)
enum {
BCM2835_CLK_MASH_0 = 0,
BCM2835_CLK_MASH_1,
BCM2835_CLK_MASH_2,
BCM2835_CLK_MASH_3,
};
enum {
BCM2835_CLK_SRC_GND = 0,
BCM2835_CLK_SRC_OSC,
BCM2835_CLK_SRC_DBG0,
BCM2835_CLK_SRC_DBG1,
BCM2835_CLK_SRC_PLLA,
BCM2835_CLK_SRC_PLLC,
BCM2835_CLK_SRC_PLLD,
BCM2835_CLK_SRC_HDMI,
};
/* Most clocks are not useable (freq = 0) */
static const unsigned int bcm2835_clk_freq[BCM2835_CLK_SRC_HDMI+1] = {
[BCM2835_CLK_SRC_GND] = 0,
[BCM2835_CLK_SRC_OSC] = 19200000,
[BCM2835_CLK_SRC_DBG0] = 0,
[BCM2835_CLK_SRC_DBG1] = 0,
[BCM2835_CLK_SRC_PLLA] = 0,
[BCM2835_CLK_SRC_PLLC] = 0,
[BCM2835_CLK_SRC_PLLD] = 500000000,
[BCM2835_CLK_SRC_HDMI] = 0,
};
/* I2S registers */
#define BCM2835_I2S_CS_A_REG 0x00
#define BCM2835_I2S_FIFO_A_REG 0x04
#define BCM2835_I2S_MODE_A_REG 0x08
#define BCM2835_I2S_RXC_A_REG 0x0c
#define BCM2835_I2S_TXC_A_REG 0x10
#define BCM2835_I2S_DREQ_A_REG 0x14
#define BCM2835_I2S_INTEN_A_REG 0x18
#define BCM2835_I2S_INTSTC_A_REG 0x1c
#define BCM2835_I2S_GRAY_REG 0x20
/* I2S register settings */
#define BCM2835_I2S_STBY BIT(25)
#define BCM2835_I2S_SYNC BIT(24)
#define BCM2835_I2S_RXSEX BIT(23)
#define BCM2835_I2S_RXF BIT(22)
#define BCM2835_I2S_TXE BIT(21)
#define BCM2835_I2S_RXD BIT(20)
#define BCM2835_I2S_TXD BIT(19)
#define BCM2835_I2S_RXR BIT(18)
#define BCM2835_I2S_TXW BIT(17)
#define BCM2835_I2S_CS_RXERR BIT(16)
#define BCM2835_I2S_CS_TXERR BIT(15)
#define BCM2835_I2S_RXSYNC BIT(14)
#define BCM2835_I2S_TXSYNC BIT(13)
#define BCM2835_I2S_DMAEN BIT(9)
#define BCM2835_I2S_RXTHR(v) ((v) << 7)
#define BCM2835_I2S_TXTHR(v) ((v) << 5)
#define BCM2835_I2S_RXCLR BIT(4)
#define BCM2835_I2S_TXCLR BIT(3)
#define BCM2835_I2S_TXON BIT(2)
#define BCM2835_I2S_RXON BIT(1)
#define BCM2835_I2S_EN (1)
#define BCM2835_I2S_CLKDIS BIT(28)
#define BCM2835_I2S_PDMN BIT(27)
#define BCM2835_I2S_PDME BIT(26)
#define BCM2835_I2S_FRXP BIT(25)
#define BCM2835_I2S_FTXP BIT(24)
#define BCM2835_I2S_CLKM BIT(23)
#define BCM2835_I2S_CLKI BIT(22)
#define BCM2835_I2S_FSM BIT(21)
#define BCM2835_I2S_FSI BIT(20)
#define BCM2835_I2S_FLEN(v) ((v) << 10)
#define BCM2835_I2S_FSLEN(v) (v)
#define BCM2835_I2S_CHWEX BIT(15)
#define BCM2835_I2S_CHEN BIT(14)
#define BCM2835_I2S_CHPOS(v) ((v) << 4)
#define BCM2835_I2S_CHWID(v) (v)
#define BCM2835_I2S_CH1(v) ((v) << 16)
#define BCM2835_I2S_CH2(v) (v)
#define BCM2835_I2S_TX_PANIC(v) ((v) << 24)
#define BCM2835_I2S_RX_PANIC(v) ((v) << 16)
#define BCM2835_I2S_TX(v) ((v) << 8)
#define BCM2835_I2S_RX(v) (v)
#define BCM2835_I2S_INT_RXERR BIT(3)
#define BCM2835_I2S_INT_TXERR BIT(2)
#define BCM2835_I2S_INT_RXR BIT(1)
#define BCM2835_I2S_INT_TXW BIT(0)
/* I2S DMA interface */
/* FIXME: Needs IOMMU support */
#define BCM2835_VCMMU_SHIFT (0x7E000000 - 0x20000000)
/* General device struct */
struct bcm2835_i2s_dev {
struct device *dev;
struct snd_dmaengine_dai_dma_data dma_data[2];
unsigned int fmt;
unsigned int bclk_ratio;
struct regmap *i2s_regmap;
struct regmap *clk_regmap;
};
static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
{
/* Start the clock if in master mode */
unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
switch (master) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBS_CFM:
regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
break;
default:
break;
}
}
static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev)
{
uint32_t clkreg;
int timeout = 1000;
/* Stop clock */
regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
BCM2835_CLK_PASSWD);
/* Wait for the BUSY flag going down */
while (--timeout) {
regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
if (!(clkreg & BCM2835_CLK_BUSY))
break;
}
if (!timeout) {
/* KILL the clock */
dev_err(dev->dev, "I2S clock didn't stop. Kill the clock!\n");
regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
BCM2835_CLK_KILL | BCM2835_CLK_PASSWD_MASK,
BCM2835_CLK_KILL | BCM2835_CLK_PASSWD);
}
}
static void bcm2835_i2s_clear_fifos(struct bcm2835_i2s_dev *dev,
bool tx, bool rx)
{
int timeout = 1000;
uint32_t syncval;
uint32_t csreg;
uint32_t i2s_active_state;
uint32_t clkreg;
uint32_t clk_active_state;
uint32_t off;
uint32_t clr;
off = tx ? BCM2835_I2S_TXON : 0;
off |= rx ? BCM2835_I2S_RXON : 0;
clr = tx ? BCM2835_I2S_TXCLR : 0;
clr |= rx ? BCM2835_I2S_RXCLR : 0;
/* Backup the current state */
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
i2s_active_state = csreg & (BCM2835_I2S_RXON | BCM2835_I2S_TXON);
regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
clk_active_state = clkreg & BCM2835_CLK_ENAB;
/* Start clock if not running */
if (!clk_active_state) {
regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
}
/* Stop I2S module */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, off, 0);
/*
* Clear the FIFOs
* Requires at least 2 PCM clock cycles to take effect
*/
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, clr, clr);
/* Wait for 2 PCM clock cycles */
/*
* Toggle the SYNC flag. After 2 PCM clock cycles it can be read back
* FIXME: This does not seem to work for slave mode!
*/
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &syncval);
syncval &= BCM2835_I2S_SYNC;
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_SYNC, ~syncval);
/* Wait for the SYNC flag changing it's state */
while (--timeout) {
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
if ((csreg & BCM2835_I2S_SYNC) != syncval)
break;
}
if (!timeout)
dev_err(dev->dev, "I2S SYNC error!\n");
/* Stop clock if it was not running before */
if (!clk_active_state)
bcm2835_i2s_stop_clock(dev);
/* Restore I2S state */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_RXON | BCM2835_I2S_TXON, i2s_active_state);
}
static int bcm2835_i2s_set_dai_fmt(struct snd_soc_dai *dai,
unsigned int fmt)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
dev->fmt = fmt;
return 0;
}
static int bcm2835_i2s_set_dai_bclk_ratio(struct snd_soc_dai *dai,
unsigned int ratio)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
dev->bclk_ratio = ratio;
return 0;
}
static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
unsigned int sampling_rate = params_rate(params);
unsigned int data_length, data_delay, bclk_ratio;
unsigned int ch1pos, ch2pos, mode, format;
unsigned int mash = BCM2835_CLK_MASH_1;
unsigned int divi, divf, target_frequency;
int clk_src = -1;
unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
bool bit_master = (master == SND_SOC_DAIFMT_CBS_CFS
|| master == SND_SOC_DAIFMT_CBS_CFM);
bool frame_master = (master == SND_SOC_DAIFMT_CBS_CFS
|| master == SND_SOC_DAIFMT_CBM_CFS);
uint32_t csreg;
/*
* If a stream is already enabled,
* the registers are already set properly.
*/
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
if (csreg & (BCM2835_I2S_TXON | BCM2835_I2S_RXON))
return 0;
/*
* Adjust the data length according to the format.
* We prefill the half frame length with an integer
* divider of 2400 as explained at the clock settings.
* Maybe it is overwritten there, if the Integer mode
* does not apply.
*/
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE:
data_length = 16;
bclk_ratio = 40;
break;
case SNDRV_PCM_FORMAT_S32_LE:
data_length = 32;
bclk_ratio = 80;
break;
default:
return -EINVAL;
}
/* If bclk_ratio already set, use that one. */
if (dev->bclk_ratio)
bclk_ratio = dev->bclk_ratio;
/*
* Clock Settings
*
* The target frequency of the bit clock is
* sampling rate * frame length
*
* Integer mode:
* Sampling rates that are multiples of 8000 kHz
* can be driven by the oscillator of 19.2 MHz
* with an integer divider as long as the frame length
* is an integer divider of 19200000/8000=2400 as set up above.
* This is no longer possible if the sampling rate
* is too high (e.g. 192 kHz), because the oscillator is too slow.
*
* MASH mode:
* For all other sampling rates, it is not possible to
* have an integer divider. Approximate the clock
* with the MASH module that induces a slight frequency
* variance. To minimize that it is best to have the fastest
* clock here. That is PLLD with 500 MHz.
*/
target_frequency = sampling_rate * bclk_ratio;
clk_src = BCM2835_CLK_SRC_OSC;
mash = BCM2835_CLK_MASH_0;
if (bcm2835_clk_freq[clk_src] % target_frequency == 0
&& bit_master && frame_master) {
divi = bcm2835_clk_freq[clk_src] / target_frequency;
divf = 0;
} else {
uint64_t dividend;
if (!dev->bclk_ratio) {
/*
* Overwrite bclk_ratio, because the
* above trick is not needed or can
* not be used.
*/
bclk_ratio = 2 * data_length;
}
target_frequency = sampling_rate * bclk_ratio;
clk_src = BCM2835_CLK_SRC_PLLD;
mash = BCM2835_CLK_MASH_1;
dividend = bcm2835_clk_freq[clk_src];
dividend <<= BCM2835_CLK_SHIFT;
do_div(dividend, target_frequency);
divi = dividend >> BCM2835_CLK_SHIFT;
divf = dividend & BCM2835_CLK_DIVF_MASK;
}
/* Set clock divider */
regmap_write(dev->clk_regmap, BCM2835_CLK_PCMDIV_REG, BCM2835_CLK_PASSWD
| BCM2835_CLK_DIVI(divi)
| BCM2835_CLK_DIVF(divf));
/* Setup clock, but don't start it yet */
regmap_write(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, BCM2835_CLK_PASSWD
| BCM2835_CLK_MASH(mash)
| BCM2835_CLK_SRC(clk_src));
/* Setup the frame format */
format = BCM2835_I2S_CHEN;
if (data_length > 24)
format |= BCM2835_I2S_CHWEX;
format |= BCM2835_I2S_CHWID((data_length-8)&0xf);
switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
data_delay = 1;
break;
default:
/*
* TODO
* Others are possible but are not implemented at the moment.
*/
dev_err(dev->dev, "%s:bad format\n", __func__);
return -EINVAL;
}
ch1pos = data_delay;
ch2pos = bclk_ratio / 2 + data_delay;
switch (params_channels(params)) {
case 2:
format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
format |= BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(ch1pos));
format |= BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(ch2pos));
break;
default:
return -EINVAL;
}
/*
* Set format for both streams.
* We cannot set another frame length
* (and therefore word length) anyway,
* so the format will be the same.
*/
regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
/* Setup the I2S mode */
mode = 0;
if (data_length <= 16) {
/*
* Use frame packed mode (2 channels per 32 bit word)
* We cannot set another frame length in the second stream
* (and therefore word length) anyway,
* so the format will be the same.
*/
mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP;
}
mode |= BCM2835_I2S_FLEN(bclk_ratio - 1);
mode |= BCM2835_I2S_FSLEN(bclk_ratio / 2);
/* Master or slave? */
switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBS_CFS:
/* CPU is master */
break;
case SND_SOC_DAIFMT_CBM_CFS:
/*
* CODEC is bit clock master
* CPU is frame master
*/
mode |= BCM2835_I2S_CLKM;
break;
case SND_SOC_DAIFMT_CBS_CFM:
/*
* CODEC is frame master
* CPU is bit clock master
*/
mode |= BCM2835_I2S_FSM;
break;
case SND_SOC_DAIFMT_CBM_CFM:
/* CODEC is master */
mode |= BCM2835_I2S_CLKM;
mode |= BCM2835_I2S_FSM;
break;
default:
dev_err(dev->dev, "%s:bad master\n", __func__);
return -EINVAL;
}
/*
* Invert clocks?
*
* The BCM approach seems to be inverted to the classical I2S approach.
*/
switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
case SND_SOC_DAIFMT_NB_NF:
/* None. Therefore, both for BCM */
mode |= BCM2835_I2S_CLKI;
mode |= BCM2835_I2S_FSI;
break;
case SND_SOC_DAIFMT_IB_IF:
/* Both. Therefore, none for BCM */
break;
case SND_SOC_DAIFMT_NB_IF:
/*
* Invert only frame sync. Therefore,
* invert only bit clock for BCM
*/
mode |= BCM2835_I2S_CLKI;
break;
case SND_SOC_DAIFMT_IB_NF:
/*
* Invert only bit clock. Therefore,
* invert only frame sync for BCM
*/
mode |= BCM2835_I2S_FSI;
break;
default:
return -EINVAL;
}
regmap_write(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, mode);
/* Setup the DMA parameters */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_RXTHR(1)
| BCM2835_I2S_TXTHR(1)
| BCM2835_I2S_DMAEN, 0xffffffff);
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_DREQ_A_REG,
BCM2835_I2S_TX_PANIC(0x10)
| BCM2835_I2S_RX_PANIC(0x30)
| BCM2835_I2S_TX(0x30)
| BCM2835_I2S_RX(0x20), 0xffffffff);
/* Clear FIFOs */
bcm2835_i2s_clear_fifos(dev, true, true);
return 0;
}
static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
uint32_t cs_reg;
bcm2835_i2s_start_clock(dev);
/*
* Clear both FIFOs if the one that should be started
* is not empty at the moment. This should only happen
* after overrun. Otherwise, hw_params would have cleared
* the FIFO.
*/
regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &cs_reg);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK
&& !(cs_reg & BCM2835_I2S_TXE))
bcm2835_i2s_clear_fifos(dev, true, false);
else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE
&& (cs_reg & BCM2835_I2S_RXD))
bcm2835_i2s_clear_fifos(dev, false, true);
return 0;
}
static void bcm2835_i2s_stop(struct bcm2835_i2s_dev *dev,
struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
uint32_t mask;
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
mask = BCM2835_I2S_RXON;
else
mask = BCM2835_I2S_TXON;
regmap_update_bits(dev->i2s_regmap,
BCM2835_I2S_CS_A_REG, mask, 0);
/* Stop also the clock when not SND_SOC_DAIFMT_CONT */
if (!dai->active && !(dev->fmt & SND_SOC_DAIFMT_CONT))
bcm2835_i2s_stop_clock(dev);
}
static int bcm2835_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
uint32_t mask;
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
bcm2835_i2s_start_clock(dev);
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
mask = BCM2835_I2S_RXON;
else
mask = BCM2835_I2S_TXON;
regmap_update_bits(dev->i2s_regmap,
BCM2835_I2S_CS_A_REG, mask, mask);
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
bcm2835_i2s_stop(dev, substream, dai);
break;
default:
return -EINVAL;
}
return 0;
}
static int bcm2835_i2s_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
if (dai->active)
return 0;
/* Should this still be running stop it */
bcm2835_i2s_stop_clock(dev);
/* Enable PCM block */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_EN, BCM2835_I2S_EN);
/*
* Disable STBY.
* Requires at least 4 PCM clock cycles to take effect.
*/
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_STBY, BCM2835_I2S_STBY);
return 0;
}
static void bcm2835_i2s_shutdown(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
bcm2835_i2s_stop(dev, substream, dai);
/* If both streams are stopped, disable module and clock */
if (dai->active)
return;
/* Disable the module */
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_EN, 0);
/*
* Stopping clock is necessary, because stop does
* not stop the clock when SND_SOC_DAIFMT_CONT
*/
bcm2835_i2s_stop_clock(dev);
}
static const struct snd_soc_dai_ops bcm2835_i2s_dai_ops = {
.startup = bcm2835_i2s_startup,
.shutdown = bcm2835_i2s_shutdown,
.prepare = bcm2835_i2s_prepare,
.trigger = bcm2835_i2s_trigger,
.hw_params = bcm2835_i2s_hw_params,
.set_fmt = bcm2835_i2s_set_dai_fmt,
.set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio
};
static int bcm2835_i2s_dai_probe(struct snd_soc_dai *dai)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
snd_soc_dai_init_dma_data(dai,
&dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK],
&dev->dma_data[SNDRV_PCM_STREAM_CAPTURE]);
return 0;
}
static struct snd_soc_dai_driver bcm2835_i2s_dai = {
.name = "bcm2835-i2s",
.probe = bcm2835_i2s_dai_probe,
.playback = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S32_LE
},
.capture = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S32_LE
},
.ops = &bcm2835_i2s_dai_ops,
.symmetric_rates = 1
};
static bool bcm2835_i2s_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case BCM2835_I2S_CS_A_REG:
case BCM2835_I2S_FIFO_A_REG:
case BCM2835_I2S_INTSTC_A_REG:
case BCM2835_I2S_GRAY_REG:
return true;
default:
return false;
};
}
static bool bcm2835_i2s_precious_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case BCM2835_I2S_FIFO_A_REG:
return true;
default:
return false;
};
}
static bool bcm2835_clk_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case BCM2835_CLK_PCMCTL_REG:
return true;
default:
return false;
};
}
static const struct regmap_config bcm2835_regmap_config[] = {
{
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.max_register = BCM2835_I2S_GRAY_REG,
.precious_reg = bcm2835_i2s_precious_reg,
.volatile_reg = bcm2835_i2s_volatile_reg,
.cache_type = REGCACHE_RBTREE,
},
{
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.max_register = BCM2835_CLK_PCMDIV_REG,
.volatile_reg = bcm2835_clk_volatile_reg,
.cache_type = REGCACHE_RBTREE,
},
};
static const struct snd_soc_component_driver bcm2835_i2s_component = {
.name = "bcm2835-i2s-comp",
};
static int bcm2835_i2s_probe(struct platform_device *pdev)
{
struct bcm2835_i2s_dev *dev;
int i;
int ret;
struct regmap *regmap[2];
struct resource *mem[2];
/* Request both ioareas */
for (i = 0; i <= 1; i++) {
void __iomem *base;
mem[i] = platform_get_resource(pdev, IORESOURCE_MEM, i);
base = devm_ioremap_resource(&pdev->dev, mem[i]);
if (IS_ERR(base))
return PTR_ERR(base);
regmap[i] = devm_regmap_init_mmio(&pdev->dev, base,
&bcm2835_regmap_config[i]);
if (IS_ERR(regmap[i]))
return PTR_ERR(regmap[i]);
}
dev = devm_kzalloc(&pdev->dev, sizeof(*dev),
GFP_KERNEL);
if (!dev)
return -ENOMEM;
dev->i2s_regmap = regmap[0];
dev->clk_regmap = regmap[1];
/* Set the DMA address */
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =
(dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
+ BCM2835_VCMMU_SHIFT;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =
(dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
+ BCM2835_VCMMU_SHIFT;
/* Set the bus width */
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr_width =
DMA_SLAVE_BUSWIDTH_4_BYTES;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr_width =
DMA_SLAVE_BUSWIDTH_4_BYTES;
/* Set burst */
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].maxburst = 2;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].maxburst = 2;
/* BCLK ratio - use default */
dev->bclk_ratio = 0;
/* Store the pdev */
dev->dev = &pdev->dev;
dev_set_drvdata(&pdev->dev, dev);
ret = devm_snd_soc_register_component(&pdev->dev,
&bcm2835_i2s_component, &bcm2835_i2s_dai, 1);
if (ret) {
dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
return ret;
}
ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
if (ret) {
dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
return ret;
}
return 0;
}
static const struct of_device_id bcm2835_i2s_of_match[] = {
{ .compatible = "brcm,bcm2835-i2s", },
{},
};
static struct platform_driver bcm2835_i2s_driver = {
.probe = bcm2835_i2s_probe,
.driver = {
.name = "bcm2835-i2s",
.of_match_table = bcm2835_i2s_of_match,
},
};
module_platform_driver(bcm2835_i2s_driver);
MODULE_ALIAS("platform:bcm2835-i2s");
MODULE_DESCRIPTION("BCM2835 I2S interface");
MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
MODULE_LICENSE("GPL v2");