stm32-dfsdm-adc.c
// SPDX-License-Identifier: GPL-2.0
/*
* This file is the ADC part of the STM32 DFSDM driver
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
*/
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/iio/adc/stm32-dfsdm-adc.h>
#include <linux/iio/buffer.h>
#include <linux/iio/hw-consumer.h>
#include <linux/iio/sysfs.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "stm32-dfsdm.h"
#define DFSDM_DMA_BUFFER_SIZE (4 * PAGE_SIZE)
/* Conversion timeout */
#define DFSDM_TIMEOUT_US 100000
#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
/* Oversampling attribute default */
#define DFSDM_DEFAULT_OVERSAMPLING 100
/* Oversampling max values */
#define DFSDM_MAX_INT_OVERSAMPLING 256
#define DFSDM_MAX_FL_OVERSAMPLING 1024
/* Max sample resolutions */
#define DFSDM_MAX_RES BIT(31)
#define DFSDM_DATA_RES BIT(23)
enum sd_converter_type {
DFSDM_AUDIO,
DFSDM_IIO,
};
struct stm32_dfsdm_dev_data {
int type;
int (*init)(struct iio_dev *indio_dev);
unsigned int num_channels;
const struct regmap_config *regmap_cfg;
};
struct stm32_dfsdm_adc {
struct stm32_dfsdm *dfsdm;
const struct stm32_dfsdm_dev_data *dev_data;
unsigned int fl_id;
/* ADC specific */
unsigned int oversamp;
struct iio_hw_consumer *hwc;
struct completion completion;
u32 *buffer;
/* Audio specific */
unsigned int spi_freq; /* SPI bus clock frequency */
unsigned int sample_freq; /* Sample frequency after filter decimation */
int (*cb)(const void *data, size_t size, void *cb_priv);
void *cb_priv;
/* DMA */
u8 *rx_buf;
unsigned int bufi; /* Buffer current position */
unsigned int buf_sz; /* Buffer size */
struct dma_chan *dma_chan;
dma_addr_t dma_buf;
};
struct stm32_dfsdm_str2field {
const char *name;
unsigned int val;
};
/* DFSDM channel serial interface type */
static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = {
{ "SPI_R", 0 }, /* SPI with data on rising edge */
{ "SPI_F", 1 }, /* SPI with data on falling edge */
{ "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */
{ "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */
{},
};
/* DFSDM channel clock source */
static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = {
/* External SPI clock (CLKIN x) */
{ "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL },
/* Internal SPI clock (CLKOUT) */
{ "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL },
/* Internal SPI clock divided by 2 (falling edge) */
{ "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING },
/* Internal SPI clock divided by 2 (falling edge) */
{ "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING },
{},
};
static int stm32_dfsdm_str2val(const char *str,
const struct stm32_dfsdm_str2field *list)
{
const struct stm32_dfsdm_str2field *p = list;
for (p = list; p && p->name; p++)
if (!strcmp(p->name, str))
return p->val;
return -EINVAL;
}
static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl,
unsigned int fast, unsigned int oversamp)
{
unsigned int i, d, fosr, iosr;
u64 res;
s64 delta;
unsigned int m = 1; /* multiplication factor */
unsigned int p = fl->ford; /* filter order (ford) */
pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp);
/*
* This function tries to compute filter oversampling and integrator
* oversampling, base on oversampling ratio requested by user.
*
* Decimation d depends on the filter order and the oversampling ratios.
* ford: filter order
* fosr: filter over sampling ratio
* iosr: integrator over sampling ratio
*/
if (fl->ford == DFSDM_FASTSINC_ORDER) {
m = 2;
p = 2;
}
/*
* Look for filter and integrator oversampling ratios which allows
* to reach 24 bits data output resolution.
* Leave as soon as if exact resolution if reached.
* Otherwise the higher resolution below 32 bits is kept.
*/
fl->res = 0;
for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
if (fast)
d = fosr * iosr;
else if (fl->ford == DFSDM_FASTSINC_ORDER)
d = fosr * (iosr + 3) + 2;
else
d = fosr * (iosr - 1 + p) + p;
if (d > oversamp)
break;
else if (d != oversamp)
continue;
/*
* Check resolution (limited to signed 32 bits)
* res <= 2^31
* Sincx filters:
* res = m * fosr^p x iosr (with m=1, p=ford)
* FastSinc filter
* res = m * fosr^p x iosr (with m=2, p=2)
*/
res = fosr;
for (i = p - 1; i > 0; i--) {
res = res * (u64)fosr;
if (res > DFSDM_MAX_RES)
break;
}
if (res > DFSDM_MAX_RES)
continue;
res = res * (u64)m * (u64)iosr;
if (res > DFSDM_MAX_RES)
continue;
delta = res - DFSDM_DATA_RES;
if (res >= fl->res) {
fl->res = res;
fl->fosr = fosr;
fl->iosr = iosr;
fl->fast = fast;
pr_debug("%s: fosr = %d, iosr = %d\n",
__func__, fl->fosr, fl->iosr);
}
if (!delta)
return 0;
}
}
if (!fl->res)
return -EINVAL;
return 0;
}
static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm,
unsigned int ch_id)
{
return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
DFSDM_CHCFGR1_CHEN_MASK,
DFSDM_CHCFGR1_CHEN(1));
}
static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm,
unsigned int ch_id)
{
regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0));
}
static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
struct stm32_dfsdm_channel *ch)
{
unsigned int id = ch->id;
struct regmap *regmap = dfsdm->regmap;
int ret;
ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
DFSDM_CHCFGR1_SITP_MASK,
DFSDM_CHCFGR1_SITP(ch->type));
if (ret < 0)
return ret;
ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
DFSDM_CHCFGR1_SPICKSEL_MASK,
DFSDM_CHCFGR1_SPICKSEL(ch->src));
if (ret < 0)
return ret;
return regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
DFSDM_CHCFGR1_CHINSEL_MASK,
DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
}
static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
unsigned int fl_id)
{
int ret;
/* Enable filter */
ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1));
if (ret < 0)
return ret;
/* Start conversion */
return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_RSWSTART_MASK,
DFSDM_CR1_RSWSTART(1));
}
static void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm,
unsigned int fl_id)
{
/* Disable conversion */
regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
}
static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
unsigned int fl_id, unsigned int ch_id)
{
struct regmap *regmap = dfsdm->regmap;
struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id];
int ret;
/* Average integrator oversampling */
ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
DFSDM_FCR_IOSR(fl->iosr - 1));
if (ret)
return ret;
/* Filter order and Oversampling */
ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK,
DFSDM_FCR_FOSR(fl->fosr - 1));
if (ret)
return ret;
ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK,
DFSDM_FCR_FORD(fl->ford));
if (ret)
return ret;
/* No scan mode supported for the moment */
ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK,
DFSDM_CR1_RCH(ch_id));
if (ret)
return ret;
return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_RSYNC_MASK,
DFSDM_CR1_RSYNC(fl->sync_mode));
}
static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
struct iio_dev *indio_dev,
struct iio_chan_spec *ch)
{
struct stm32_dfsdm_channel *df_ch;
const char *of_str;
int chan_idx = ch->scan_index;
int ret, val;
ret = of_property_read_u32_index(indio_dev->dev.of_node,
"st,adc-channels", chan_idx,
&ch->channel);
if (ret < 0) {
dev_err(&indio_dev->dev,
" Error parsing 'st,adc-channels' for idx %d\n",
chan_idx);
return ret;
}
if (ch->channel >= dfsdm->num_chs) {
dev_err(&indio_dev->dev,
" Error bad channel number %d (max = %d)\n",
ch->channel, dfsdm->num_chs);
return -EINVAL;
}
ret = of_property_read_string_index(indio_dev->dev.of_node,
"st,adc-channel-names", chan_idx,
&ch->datasheet_name);
if (ret < 0) {
dev_err(&indio_dev->dev,
" Error parsing 'st,adc-channel-names' for idx %d\n",
chan_idx);
return ret;
}
df_ch = &dfsdm->ch_list[ch->channel];
df_ch->id = ch->channel;
ret = of_property_read_string_index(indio_dev->dev.of_node,
"st,adc-channel-types", chan_idx,
&of_str);
if (!ret) {
val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
if (val < 0)
return val;
} else {
val = 0;
}
df_ch->type = val;
ret = of_property_read_string_index(indio_dev->dev.of_node,
"st,adc-channel-clk-src", chan_idx,
&of_str);
if (!ret) {
val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
if (val < 0)
return val;
} else {
val = 0;
}
df_ch->src = val;
ret = of_property_read_u32_index(indio_dev->dev.of_node,
"st,adc-alt-channel", chan_idx,
&df_ch->alt_si);
if (ret < 0)
df_ch->alt_si = 0;
return 0;
}
static ssize_t dfsdm_adc_audio_get_spiclk(struct iio_dev *indio_dev,
uintptr_t priv,
const struct iio_chan_spec *chan,
char *buf)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
return snprintf(buf, PAGE_SIZE, "%d\n", adc->spi_freq);
}
static ssize_t dfsdm_adc_audio_set_spiclk(struct iio_dev *indio_dev,
uintptr_t priv,
const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
unsigned int sample_freq = adc->sample_freq;
unsigned int spi_freq;
int ret;
dev_err(&indio_dev->dev, "enter %s\n", __func__);
/* If DFSDM is master on SPI, SPI freq can not be updated */
if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
return -EPERM;
ret = kstrtoint(buf, 0, &spi_freq);
if (ret)
return ret;
if (!spi_freq)
return -EINVAL;
if (sample_freq) {
if (spi_freq % sample_freq)
dev_warn(&indio_dev->dev,
"Sampling rate not accurate (%d)\n",
spi_freq / (spi_freq / sample_freq));
ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / sample_freq));
if (ret < 0) {
dev_err(&indio_dev->dev,
"No filter parameters that match!\n");
return ret;
}
}
adc->spi_freq = spi_freq;
return len;
}
static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc,
const struct iio_chan_spec *chan,
bool dma)
{
struct regmap *regmap = adc->dfsdm->regmap;
int ret;
unsigned int dma_en = 0, cont_en = 0;
ret = stm32_dfsdm_start_channel(adc->dfsdm, chan->channel);
if (ret < 0)
return ret;
ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
chan->channel);
if (ret < 0)
goto stop_channels;
if (dma) {
/* Enable DMA transfer*/
dma_en = DFSDM_CR1_RDMAEN(1);
/* Enable conversion triggered by SPI clock*/
cont_en = DFSDM_CR1_RCONT(1);
}
/* Enable DMA transfer*/
ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RDMAEN_MASK, dma_en);
if (ret < 0)
goto stop_channels;
/* Enable conversion triggered by SPI clock*/
ret = regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RCONT_MASK, cont_en);
if (ret < 0)
goto stop_channels;
ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
if (ret < 0)
goto stop_channels;
return 0;
stop_channels:
regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RDMAEN_MASK, 0);
regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RCONT_MASK, 0);
stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
return ret;
}
static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc,
const struct iio_chan_spec *chan)
{
struct regmap *regmap = adc->dfsdm->regmap;
stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
/* Clean conversion options */
regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RDMAEN_MASK, 0);
regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RCONT_MASK, 0);
stm32_dfsdm_stop_channel(adc->dfsdm, chan->channel);
}
static int stm32_dfsdm_set_watermark(struct iio_dev *indio_dev,
unsigned int val)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
unsigned int watermark = DFSDM_DMA_BUFFER_SIZE / 2;
/*
* DMA cyclic transfers are used, buffer is split into two periods.
* There should be :
* - always one buffer (period) DMA is working on
* - one buffer (period) driver pushed to ASoC side.
*/
watermark = min(watermark, val * (unsigned int)(sizeof(u32)));
adc->buf_sz = watermark * 2;
return 0;
}
static unsigned int stm32_dfsdm_adc_dma_residue(struct stm32_dfsdm_adc *adc)
{
struct dma_tx_state state;
enum dma_status status;
status = dmaengine_tx_status(adc->dma_chan,
adc->dma_chan->cookie,
&state);
if (status == DMA_IN_PROGRESS) {
/* Residue is size in bytes from end of buffer */
unsigned int i = adc->buf_sz - state.residue;
unsigned int size;
/* Return available bytes */
if (i >= adc->bufi)
size = i - adc->bufi;
else
size = adc->buf_sz + i - adc->bufi;
return size;
}
return 0;
}
static void stm32_dfsdm_audio_dma_buffer_done(void *data)
{
struct iio_dev *indio_dev = data;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int available = stm32_dfsdm_adc_dma_residue(adc);
size_t old_pos;
/*
* FIXME: In Kernel interface does not support cyclic DMA buffer,and
* offers only an interface to push data samples per samples.
* For this reason IIO buffer interface is not used and interface is
* bypassed using a private callback registered by ASoC.
* This should be a temporary solution waiting a cyclic DMA engine
* support in IIO.
*/
dev_dbg(&indio_dev->dev, "%s: pos = %d, available = %d\n", __func__,
adc->bufi, available);
old_pos = adc->bufi;
while (available >= indio_dev->scan_bytes) {
u32 *buffer = (u32 *)&adc->rx_buf[adc->bufi];
/* Mask 8 LSB that contains the channel ID */
*buffer = (*buffer & 0xFFFFFF00) << 8;
available -= indio_dev->scan_bytes;
adc->bufi += indio_dev->scan_bytes;
if (adc->bufi >= adc->buf_sz) {
if (adc->cb)
adc->cb(&adc->rx_buf[old_pos],
adc->buf_sz - old_pos, adc->cb_priv);
adc->bufi = 0;
old_pos = 0;
}
}
if (adc->cb)
adc->cb(&adc->rx_buf[old_pos], adc->bufi - old_pos,
adc->cb_priv);
}
static int stm32_dfsdm_adc_dma_start(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct dma_async_tx_descriptor *desc;
dma_cookie_t cookie;
int ret;
if (!adc->dma_chan)
return -EINVAL;
dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
adc->buf_sz, adc->buf_sz / 2);
/* Prepare a DMA cyclic transaction */
desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
adc->dma_buf,
adc->buf_sz, adc->buf_sz / 2,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!desc)
return -EBUSY;
desc->callback = stm32_dfsdm_audio_dma_buffer_done;
desc->callback_param = indio_dev;
cookie = dmaengine_submit(desc);
ret = dma_submit_error(cookie);
if (ret) {
dmaengine_terminate_all(adc->dma_chan);
return ret;
}
/* Issue pending DMA requests */
dma_async_issue_pending(adc->dma_chan);
return 0;
}
static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
const struct iio_chan_spec *chan = &indio_dev->channels[0];
int ret;
/* Reset adc buffer index */
adc->bufi = 0;
ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
if (ret < 0)
return ret;
ret = stm32_dfsdm_start_conv(adc, chan, true);
if (ret) {
dev_err(&indio_dev->dev, "Can't start conversion\n");
goto stop_dfsdm;
}
if (adc->dma_chan) {
ret = stm32_dfsdm_adc_dma_start(indio_dev);
if (ret) {
dev_err(&indio_dev->dev, "Can't start DMA\n");
goto err_stop_conv;
}
}
return 0;
err_stop_conv:
stm32_dfsdm_stop_conv(adc, chan);
stop_dfsdm:
stm32_dfsdm_stop_dfsdm(adc->dfsdm);
return ret;
}
static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
const struct iio_chan_spec *chan = &indio_dev->channels[0];
if (adc->dma_chan)
dmaengine_terminate_all(adc->dma_chan);
stm32_dfsdm_stop_conv(adc, chan);
stm32_dfsdm_stop_dfsdm(adc->dfsdm);
return 0;
}
static const struct iio_buffer_setup_ops stm32_dfsdm_buffer_setup_ops = {
.postenable = &stm32_dfsdm_postenable,
.predisable = &stm32_dfsdm_predisable,
};
/**
* stm32_dfsdm_get_buff_cb() - register a callback that will be called when
* DMA transfer period is achieved.
*
* @iio_dev: Handle to IIO device.
* @cb: Pointer to callback function:
* - data: pointer to data buffer
* - size: size in byte of the data buffer
* - private: pointer to consumer private structure.
* @private: Pointer to consumer private structure.
*/
int stm32_dfsdm_get_buff_cb(struct iio_dev *iio_dev,
int (*cb)(const void *data, size_t size,
void *private),
void *private)
{
struct stm32_dfsdm_adc *adc;
if (!iio_dev)
return -EINVAL;
adc = iio_priv(iio_dev);
adc->cb = cb;
adc->cb_priv = private;
return 0;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_get_buff_cb);
/**
* stm32_dfsdm_release_buff_cb - unregister buffer callback
*
* @iio_dev: Handle to IIO device.
*/
int stm32_dfsdm_release_buff_cb(struct iio_dev *iio_dev)
{
struct stm32_dfsdm_adc *adc;
if (!iio_dev)
return -EINVAL;
adc = iio_priv(iio_dev);
adc->cb = NULL;
adc->cb_priv = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(stm32_dfsdm_release_buff_cb);
static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, int *res)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
long timeout;
int ret;
reinit_completion(&adc->completion);
adc->buffer = res;
ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
if (ret < 0)
return ret;
ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
if (ret < 0)
goto stop_dfsdm;
ret = stm32_dfsdm_start_conv(adc, chan, false);
if (ret < 0) {
regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
goto stop_dfsdm;
}
timeout = wait_for_completion_interruptible_timeout(&adc->completion,
DFSDM_TIMEOUT);
/* Mask IRQ for regular conversion achievement*/
regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
if (timeout == 0)
ret = -ETIMEDOUT;
else if (timeout < 0)
ret = timeout;
else
ret = IIO_VAL_INT;
stm32_dfsdm_stop_conv(adc, chan);
stop_dfsdm:
stm32_dfsdm_stop_dfsdm(adc->dfsdm);
return ret;
}
static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
unsigned int spi_freq;
int ret = -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
ret = stm32_dfsdm_set_osrs(fl, 0, val);
if (!ret)
adc->oversamp = val;
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
if (!val)
return -EINVAL;
switch (ch->src) {
case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL:
spi_freq = adc->dfsdm->spi_master_freq;
break;
case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING:
case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING:
spi_freq = adc->dfsdm->spi_master_freq / 2;
break;
default:
spi_freq = adc->spi_freq;
}
if (spi_freq % val)
dev_warn(&indio_dev->dev,
"Sampling rate not accurate (%d)\n",
spi_freq / (spi_freq / val));
ret = stm32_dfsdm_set_osrs(fl, 0, (spi_freq / val));
if (ret < 0) {
dev_err(&indio_dev->dev,
"Not able to find parameter that match!\n");
return ret;
}
adc->sample_freq = val;
return 0;
}
return -EINVAL;
}
static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iio_hw_consumer_enable(adc->hwc);
if (ret < 0) {
dev_err(&indio_dev->dev,
"%s: IIO enable failed (channel %d)\n",
__func__, chan->channel);
return ret;
}
ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
iio_hw_consumer_disable(adc->hwc);
if (ret < 0) {
dev_err(&indio_dev->dev,
"%s: Conversion failed (channel %d)\n",
__func__, chan->channel);
return ret;
}
return IIO_VAL_INT;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = adc->oversamp;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = adc->sample_freq;
return IIO_VAL_INT;
}
return -EINVAL;
}
static const struct iio_info stm32_dfsdm_info_audio = {
.hwfifo_set_watermark = stm32_dfsdm_set_watermark,
.read_raw = stm32_dfsdm_read_raw,
.write_raw = stm32_dfsdm_write_raw,
};
static const struct iio_info stm32_dfsdm_info_adc = {
.read_raw = stm32_dfsdm_read_raw,
.write_raw = stm32_dfsdm_write_raw,
};
static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
{
struct stm32_dfsdm_adc *adc = arg;
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
struct regmap *regmap = adc->dfsdm->regmap;
unsigned int status, int_en;
regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en);
if (status & DFSDM_ISR_REOCF_MASK) {
/* Read the data register clean the IRQ status */
regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer);
complete(&adc->completion);
}
if (status & DFSDM_ISR_ROVRF_MASK) {
if (int_en & DFSDM_CR2_ROVRIE_MASK)
dev_warn(&indio_dev->dev, "Overrun detected\n");
regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
DFSDM_ICR_CLRROVRF_MASK,
DFSDM_ICR_CLRROVRF_MASK);
}
return IRQ_HANDLED;
}
/*
* Define external info for SPI Frequency and audio sampling rate that can be
* configured by ASoC driver through consumer.h API
*/
static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
/* spi_clk_freq : clock freq on SPI/manchester bus used by channel */
{
.name = "spi_clk_freq",
.shared = IIO_SHARED_BY_TYPE,
.read = dfsdm_adc_audio_get_spiclk,
.write = dfsdm_adc_audio_set_spiclk,
},
{},
};
static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
if (adc->dma_chan) {
dma_free_coherent(adc->dma_chan->device->dev,
DFSDM_DMA_BUFFER_SIZE,
adc->rx_buf, adc->dma_buf);
dma_release_channel(adc->dma_chan);
}
}
static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct dma_slave_config config = {
.src_addr = (dma_addr_t)adc->dfsdm->phys_base +
DFSDM_RDATAR(adc->fl_id),
.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
};
int ret;
adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx");
if (!adc->dma_chan)
return -EINVAL;
adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
DFSDM_DMA_BUFFER_SIZE,
&adc->dma_buf, GFP_KERNEL);
if (!adc->rx_buf) {
ret = -ENOMEM;
goto err_release;
}
ret = dmaengine_slave_config(adc->dma_chan, &config);
if (ret)
goto err_free;
return 0;
err_free:
dma_free_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
adc->rx_buf, adc->dma_buf);
err_release:
dma_release_channel(adc->dma_chan);
return ret;
}
static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
struct iio_chan_spec *ch)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int ret;
ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
if (ret < 0)
return ret;
ch->type = IIO_VOLTAGE;
ch->indexed = 1;
/*
* IIO_CHAN_INFO_RAW: used to compute regular conversion
* IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling
*/
ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
if (adc->dev_data->type == DFSDM_AUDIO) {
ch->scan_type.sign = 's';
ch->ext_info = dfsdm_adc_audio_ext_info;
} else {
ch->scan_type.sign = 'u';
}
ch->scan_type.realbits = 24;
ch->scan_type.storagebits = 32;
return stm32_dfsdm_chan_configure(adc->dfsdm,
&adc->dfsdm->ch_list[ch->channel]);
}
static int stm32_dfsdm_audio_init(struct iio_dev *indio_dev)
{
struct iio_chan_spec *ch;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct stm32_dfsdm_channel *d_ch;
int ret;
indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
if (!ch)
return -ENOMEM;
ch->scan_index = 0;
ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
if (ret < 0) {
dev_err(&indio_dev->dev, "Channels init failed\n");
return ret;
}
ch->info_mask_separate = BIT(IIO_CHAN_INFO_SAMP_FREQ);
d_ch = &adc->dfsdm->ch_list[ch->channel];
if (d_ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
adc->spi_freq = adc->dfsdm->spi_master_freq;
indio_dev->num_channels = 1;
indio_dev->channels = ch;
return stm32_dfsdm_dma_request(indio_dev);
}
static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
{
struct iio_chan_spec *ch;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int num_ch;
int ret, chan_idx;
adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0,
adc->oversamp);
if (ret < 0)
return ret;
num_ch = of_property_count_u32_elems(indio_dev->dev.of_node,
"st,adc-channels");
if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) {
dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
return num_ch < 0 ? num_ch : -EINVAL;
}
/* Bind to SD modulator IIO device */
adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
if (IS_ERR(adc->hwc))
return -EPROBE_DEFER;
ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
GFP_KERNEL);
if (!ch)
return -ENOMEM;
for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
ch[chan_idx].scan_index = chan_idx;
ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &ch[chan_idx]);
if (ret < 0) {
dev_err(&indio_dev->dev, "Channels init failed\n");
return ret;
}
}
indio_dev->num_channels = num_ch;
indio_dev->channels = ch;
init_completion(&adc->completion);
return 0;
}
static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
.type = DFSDM_IIO,
.init = stm32_dfsdm_adc_init,
};
static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_audio_data = {
.type = DFSDM_AUDIO,
.init = stm32_dfsdm_audio_init,
};
static const struct of_device_id stm32_dfsdm_adc_match[] = {
{
.compatible = "st,stm32-dfsdm-adc",
.data = &stm32h7_dfsdm_adc_data,
},
{
.compatible = "st,stm32-dfsdm-dmic",
.data = &stm32h7_dfsdm_audio_data,
},
{}
};
static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct stm32_dfsdm_adc *adc;
struct device_node *np = dev->of_node;
const struct stm32_dfsdm_dev_data *dev_data;
struct iio_dev *iio;
char *name;
int ret, irq, val;
dev_data = of_device_get_match_data(dev);
iio = devm_iio_device_alloc(dev, sizeof(*adc));
if (!iio) {
dev_err(dev, "%s: Failed to allocate IIO\n", __func__);
return -ENOMEM;
}
adc = iio_priv(iio);
adc->dfsdm = dev_get_drvdata(dev->parent);
iio->dev.parent = dev;
iio->dev.of_node = np;
iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
platform_set_drvdata(pdev, adc);
ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
if (ret != 0 || adc->fl_id >= adc->dfsdm->num_fls) {
dev_err(dev, "Missing or bad reg property\n");
return -EINVAL;
}
name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
if (!name)
return -ENOMEM;
if (dev_data->type == DFSDM_AUDIO) {
iio->info = &stm32_dfsdm_info_audio;
snprintf(name, sizeof("dfsdm-pdm0"), "dfsdm-pdm%d", adc->fl_id);
} else {
iio->info = &stm32_dfsdm_info_adc;
snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
}
iio->name = name;
/*
* In a first step IRQs generated for channels are not treated.
* So IRQ associated to filter instance 0 is dedicated to the Filter 0.
*/
irq = platform_get_irq(pdev, 0);
ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
0, pdev->name, adc);
if (ret < 0) {
dev_err(dev, "Failed to request IRQ\n");
return ret;
}
ret = of_property_read_u32(dev->of_node, "st,filter-order", &val);
if (ret < 0) {
dev_err(dev, "Failed to set filter order\n");
return ret;
}
adc->dfsdm->fl_list[adc->fl_id].ford = val;
ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val);
if (!ret)
adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
adc->dev_data = dev_data;
ret = dev_data->init(iio);
if (ret < 0)
return ret;
ret = iio_device_register(iio);
if (ret < 0)
goto err_cleanup;
if (dev_data->type == DFSDM_AUDIO) {
ret = of_platform_populate(np, NULL, NULL, dev);
if (ret < 0) {
dev_err(dev, "Failed to find an audio DAI\n");
goto err_unregister;
}
}
return 0;
err_unregister:
iio_device_unregister(iio);
err_cleanup:
stm32_dfsdm_dma_release(iio);
return ret;
}
static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
{
struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
if (adc->dev_data->type == DFSDM_AUDIO)
of_platform_depopulate(&pdev->dev);
iio_device_unregister(indio_dev);
stm32_dfsdm_dma_release(indio_dev);
return 0;
}
static struct platform_driver stm32_dfsdm_adc_driver = {
.driver = {
.name = "stm32-dfsdm-adc",
.of_match_table = stm32_dfsdm_adc_match,
},
.probe = stm32_dfsdm_adc_probe,
.remove = stm32_dfsdm_adc_remove,
};
module_platform_driver(stm32_dfsdm_adc_driver);
MODULE_DESCRIPTION("STM32 sigma delta ADC");
MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
MODULE_LICENSE("GPL v2");
