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linux-zen-server/sound/soc/bcm/bcm2835-i2s.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
/* 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_CH1_POS(v) BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(v))
#define BCM2835_I2S_CH2_POS(v) BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(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)
/* Frame length register is 10 bit, maximum length 1024 */
#define BCM2835_I2S_MAX_FRAME_LENGTH 1024
/* General device struct */
struct bcm2835_i2s_dev {
struct device *dev;
struct snd_dmaengine_dai_dma_data dma_data[2];
unsigned int fmt;
unsigned int tdm_slots;
unsigned int rx_mask;
unsigned int tx_mask;
unsigned int slot_width;
unsigned int frame_length;
struct regmap *i2s_regmap;
struct clk *clk;
bool clk_prepared;
int clk_rate;
};
static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
{
unsigned int provider = dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK;
if (dev->clk_prepared)
return;
switch (provider) {
case SND_SOC_DAIFMT_BP_FP:
case SND_SOC_DAIFMT_BP_FC:
clk_prepare_enable(dev->clk);
dev->clk_prepared = true;
break;
default:
break;
}
}
static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev)
{
if (dev->clk_prepared)
clk_disable_unprepare(dev->clk);
dev->clk_prepared = false;
}
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;
bool clk_was_prepared;
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);
/* Start clock if not running */
clk_was_prepared = dev->clk_prepared;
if (!clk_was_prepared)
bcm2835_i2s_start_clock(dev);
/* 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_was_prepared)
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);
if (!ratio) {
dev->tdm_slots = 0;
return 0;
}
if (ratio > BCM2835_I2S_MAX_FRAME_LENGTH)
return -EINVAL;
dev->tdm_slots = 2;
dev->rx_mask = 0x03;
dev->tx_mask = 0x03;
dev->slot_width = ratio / 2;
dev->frame_length = ratio;
return 0;
}
static int bcm2835_i2s_set_dai_tdm_slot(struct snd_soc_dai *dai,
unsigned int tx_mask, unsigned int rx_mask,
int slots, int width)
{
struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
if (slots) {
if (slots < 0 || width < 0)
return -EINVAL;
/* Limit masks to available slots */
rx_mask &= GENMASK(slots - 1, 0);
tx_mask &= GENMASK(slots - 1, 0);
/*
* The driver is limited to 2-channel setups.
* Check that exactly 2 bits are set in the masks.
*/
if (hweight_long((unsigned long) rx_mask) != 2
|| hweight_long((unsigned long) tx_mask) != 2)
return -EINVAL;
if (slots * width > BCM2835_I2S_MAX_FRAME_LENGTH)
return -EINVAL;
}
dev->tdm_slots = slots;
dev->rx_mask = rx_mask;
dev->tx_mask = tx_mask;
dev->slot_width = width;
dev->frame_length = slots * width;
return 0;
}
/*
* Convert logical slot number into physical slot number.
*
* If odd_offset is 0 sequential number is identical to logical number.
* This is used for DSP modes with slot numbering 0 1 2 3 ...
*
* Otherwise odd_offset defines the physical offset for odd numbered
* slots. This is used for I2S and left/right justified modes to
* translate from logical slot numbers 0 1 2 3 ... into physical slot
* numbers 0 2 ... 3 4 ...
*/
static int bcm2835_i2s_convert_slot(unsigned int slot, unsigned int odd_offset)
{
if (!odd_offset)
return slot;
if (slot & 1)
return (slot >> 1) + odd_offset;
return slot >> 1;
}
/*
* Calculate channel position from mask and slot width.
*
* Mask must contain exactly 2 set bits.
* Lowest set bit is channel 1 position, highest set bit channel 2.
* The constant offset is added to both channel positions.
*
* If odd_offset is > 0 slot positions are translated to
* I2S-style TDM slot numbering ( 0 2 ... 3 4 ...) with odd
* logical slot numbers starting at physical slot odd_offset.
*/
static void bcm2835_i2s_calc_channel_pos(
unsigned int *ch1_pos, unsigned int *ch2_pos,
unsigned int mask, unsigned int width,
unsigned int bit_offset, unsigned int odd_offset)
{
*ch1_pos = bcm2835_i2s_convert_slot((ffs(mask) - 1), odd_offset)
* width + bit_offset;
*ch2_pos = bcm2835_i2s_convert_slot((fls(mask) - 1), odd_offset)
* width + bit_offset;
}
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 data_length, data_delay, framesync_length;
unsigned int slots, slot_width, odd_slot_offset;
int frame_length, bclk_rate;
unsigned int rx_mask, tx_mask;
unsigned int rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos;
unsigned int mode, format;
bool bit_clock_provider = false;
bool frame_sync_provider = false;
bool frame_start_falling_edge = false;
uint32_t csreg;
int ret = 0;
/*
* 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;
data_length = params_width(params);
data_delay = 0;
odd_slot_offset = 0;
mode = 0;
if (dev->tdm_slots) {
slots = dev->tdm_slots;
slot_width = dev->slot_width;
frame_length = dev->frame_length;
rx_mask = dev->rx_mask;
tx_mask = dev->tx_mask;
bclk_rate = dev->frame_length * params_rate(params);
} else {
slots = 2;
slot_width = params_width(params);
rx_mask = 0x03;
tx_mask = 0x03;
frame_length = snd_soc_params_to_frame_size(params);
if (frame_length < 0)
return frame_length;
bclk_rate = snd_soc_params_to_bclk(params);
if (bclk_rate < 0)
return bclk_rate;
}
/* Check if data fits into slots */
if (data_length > slot_width)
return -EINVAL;
/* Check if CPU is bit clock provider */
switch (dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
case SND_SOC_DAIFMT_BP_FP:
case SND_SOC_DAIFMT_BP_FC:
bit_clock_provider = true;
break;
case SND_SOC_DAIFMT_BC_FP:
case SND_SOC_DAIFMT_BC_FC:
bit_clock_provider = false;
break;
default:
return -EINVAL;
}
/* Check if CPU is frame sync provider */
switch (dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
case SND_SOC_DAIFMT_BP_FP:
case SND_SOC_DAIFMT_BC_FP:
frame_sync_provider = true;
break;
case SND_SOC_DAIFMT_BP_FC:
case SND_SOC_DAIFMT_BC_FC:
frame_sync_provider = false;
break;
default:
return -EINVAL;
}
/* Clock should only be set up here if CPU is clock master */
if (bit_clock_provider &&
(!dev->clk_prepared || dev->clk_rate != bclk_rate)) {
if (dev->clk_prepared)
bcm2835_i2s_stop_clock(dev);
if (dev->clk_rate != bclk_rate) {
ret = clk_set_rate(dev->clk, bclk_rate);
if (ret)
return ret;
dev->clk_rate = bclk_rate;
}
bcm2835_i2s_start_clock(dev);
}
/* Setup the frame format */
format = BCM2835_I2S_CHEN;
if (data_length >= 24)
format |= BCM2835_I2S_CHWEX;
format |= BCM2835_I2S_CHWID((data_length-8)&0xf);
/* CH2 format is the same as for CH1 */
format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
/* I2S mode needs an even number of slots */
if (slots & 1)
return -EINVAL;
/*
* Use I2S-style logical slot numbering: even slots
* are in first half of frame, odd slots in second half.
*/
odd_slot_offset = slots >> 1;
/* MSB starts one cycle after frame start */
data_delay = 1;
/* Setup frame sync signal for 50% duty cycle */
framesync_length = frame_length / 2;
frame_start_falling_edge = true;
break;
case SND_SOC_DAIFMT_LEFT_J:
if (slots & 1)
return -EINVAL;
odd_slot_offset = slots >> 1;
data_delay = 0;
framesync_length = frame_length / 2;
frame_start_falling_edge = false;
break;
case SND_SOC_DAIFMT_RIGHT_J:
if (slots & 1)
return -EINVAL;
/* Odd frame lengths aren't supported */
if (frame_length & 1)
return -EINVAL;
odd_slot_offset = slots >> 1;
data_delay = slot_width - data_length;
framesync_length = frame_length / 2;
frame_start_falling_edge = false;
break;
case SND_SOC_DAIFMT_DSP_A:
data_delay = 1;
framesync_length = 1;
frame_start_falling_edge = false;
break;
case SND_SOC_DAIFMT_DSP_B:
data_delay = 0;
framesync_length = 1;
frame_start_falling_edge = false;
break;
default:
return -EINVAL;
}
bcm2835_i2s_calc_channel_pos(&rx_ch1_pos, &rx_ch2_pos,
rx_mask, slot_width, data_delay, odd_slot_offset);
bcm2835_i2s_calc_channel_pos(&tx_ch1_pos, &tx_ch2_pos,
tx_mask, slot_width, data_delay, odd_slot_offset);
/*
* Transmitting data immediately after frame start, eg
* in left-justified or DSP mode A, only works stable
* if bcm2835 is the frame clock provider.
*/
if ((!rx_ch1_pos || !tx_ch1_pos) && !frame_sync_provider)
dev_warn(dev->dev,
"Unstable consumer config detected, L/R may be swapped");
/*
* 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
| BCM2835_I2S_CH1_POS(rx_ch1_pos)
| BCM2835_I2S_CH2_POS(rx_ch2_pos));
regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG,
format
| BCM2835_I2S_CH1_POS(tx_ch1_pos)
| BCM2835_I2S_CH2_POS(tx_ch2_pos));
/* Setup the I2S mode */
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(frame_length - 1);
mode |= BCM2835_I2S_FSLEN(framesync_length);
/* CLKM selects bcm2835 clock slave mode */
if (!bit_clock_provider)
mode |= BCM2835_I2S_CLKM;
/* FSM selects bcm2835 frame sync slave mode */
if (!frame_sync_provider)
mode |= BCM2835_I2S_FSM;
/* CLKI selects normal clocking mode, sampling on rising edge */
switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
case SND_SOC_DAIFMT_NB_NF:
case SND_SOC_DAIFMT_NB_IF:
mode |= BCM2835_I2S_CLKI;
break;
case SND_SOC_DAIFMT_IB_NF:
case SND_SOC_DAIFMT_IB_IF:
break;
default:
return -EINVAL;
}
/* FSI selects frame start on falling edge */
switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
case SND_SOC_DAIFMT_NB_NF:
case SND_SOC_DAIFMT_IB_NF:
if (frame_start_falling_edge)
mode |= BCM2835_I2S_FSI;
break;
case SND_SOC_DAIFMT_NB_IF:
case SND_SOC_DAIFMT_IB_IF:
if (!frame_start_falling_edge)
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);
dev_dbg(dev->dev,
"slots: %d width: %d rx mask: 0x%02x tx_mask: 0x%02x\n",
slots, slot_width, rx_mask, tx_mask);
dev_dbg(dev->dev, "frame len: %d sync len: %d data len: %d\n",
frame_length, framesync_length, data_length);
dev_dbg(dev->dev, "rx pos: %d,%d tx pos: %d,%d\n",
rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos);
dev_dbg(dev->dev, "sampling rate: %d bclk rate: %d\n",
params_rate(params), bclk_rate);
dev_dbg(dev->dev, "CLKM: %d CLKI: %d FSM: %d FSI: %d frame start: %s edge\n",
!!(mode & BCM2835_I2S_CLKM),
!!(mode & BCM2835_I2S_CLKI),
!!(mode & BCM2835_I2S_FSM),
!!(mode & BCM2835_I2S_FSI),
(mode & BCM2835_I2S_FSI) ? "falling" : "rising");
return ret;
}
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;
/*
* 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 (!snd_soc_dai_active(dai) && !(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 (snd_soc_dai_active(dai))
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 (snd_soc_dai_active(dai))
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,
.set_tdm_slot = bcm2835_i2s_set_dai_tdm_slot,
};
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_CONTINUOUS,
.rate_min = 8000,
.rate_max = 384000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S24_LE
| SNDRV_PCM_FMTBIT_S32_LE
},
.capture = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_CONTINUOUS,
.rate_min = 8000,
.rate_max = 384000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S24_LE
| SNDRV_PCM_FMTBIT_S32_LE
},
.ops = &bcm2835_i2s_dai_ops,
.symmetric_rate = 1,
.symmetric_sample_bits = 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 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,
};
static const struct snd_soc_component_driver bcm2835_i2s_component = {
.name = "bcm2835-i2s-comp",
.legacy_dai_naming = 1,
};
static int bcm2835_i2s_probe(struct platform_device *pdev)
{
struct bcm2835_i2s_dev *dev;
int ret;
void __iomem *base;
const __be32 *addr;
dma_addr_t dma_base;
dev = devm_kzalloc(&pdev->dev, sizeof(*dev),
GFP_KERNEL);
if (!dev)
return -ENOMEM;
/* get the clock */
dev->clk_prepared = false;
dev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk),
"could not get clk\n");
/* Request ioarea */
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
dev->i2s_regmap = devm_regmap_init_mmio(&pdev->dev, base,
&bcm2835_regmap_config);
if (IS_ERR(dev->i2s_regmap))
return PTR_ERR(dev->i2s_regmap);
/* Set the DMA address - we have to parse DT ourselves */
addr = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
if (!addr) {
dev_err(&pdev->dev, "could not get DMA-register address\n");
return -EINVAL;
}
dma_base = be32_to_cpup(addr);
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =
dma_base + BCM2835_I2S_FIFO_A_REG;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =
dma_base + BCM2835_I2S_FIFO_A_REG;
/* 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;
/*
* Set the PACK flag to enable S16_LE support (2 S16_LE values
* packed into 32-bit transfers).
*/
dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].flags =
SND_DMAENGINE_PCM_DAI_FLAG_PACK;
dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].flags =
SND_DMAENGINE_PCM_DAI_FLAG_PACK;
/* 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", },
{},
};
MODULE_DEVICE_TABLE(of, bcm2835_i2s_of_match);
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");