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linux/sound/soc/bcm/bcm2835-i2s.c
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00

935 lines
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// 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 master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
if (dev->clk_prepared)
return;
switch (master) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBS_CFM:
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_master = false;
bool frame_sync_master = 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 master */
switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBS_CFM:
bit_clock_master = true;
break;
case SND_SOC_DAIFMT_CBM_CFS:
case SND_SOC_DAIFMT_CBM_CFM:
bit_clock_master = false;
break;
default:
return -EINVAL;
}
/* Check if CPU is frame sync master */
switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBS_CFS:
case SND_SOC_DAIFMT_CBM_CFS:
frame_sync_master = true;
break;
case SND_SOC_DAIFMT_CBS_CFM:
case SND_SOC_DAIFMT_CBM_CFM:
frame_sync_master = false;
break;
default:
return -EINVAL;
}
/* Clock should only be set up here if CPU is clock master */
if (bit_clock_master &&
(!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 master.
*/
if ((!rx_ch1_pos || !tx_ch1_pos) && !frame_sync_master)
dev_warn(dev->dev,
"Unstable slave 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_master)
mode |= BCM2835_I2S_CLKM;
/* FSM selects bcm2835 frame sync slave mode */
if (!frame_sync_master)
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 (!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,
.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_rates = 1,
.symmetric_samplebits = 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",
};
static int bcm2835_i2s_probe(struct platform_device *pdev)
{
struct bcm2835_i2s_dev *dev;
int ret;
struct resource *mem;
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)) {
dev_err(&pdev->dev, "could not get clk: %ld\n",
PTR_ERR(dev->clk));
return PTR_ERR(dev->clk);
}
/* Request ioarea */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, mem);
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");
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