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android-kvm / linux / refs/heads/for-upstream/guestmem / . / drivers / iio / adc / stm32-dfsdm-adc.c
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// 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/backend.h>
#include <linux/iio/buffer.h>
#include <linux/iio/hw-consumer.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/timer/stm32-lptim-trigger.h>
#include <linux/iio/timer/stm32-timer-trigger.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.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
/* Limit filter output resolution to 31 bits. (i.e. sample range is +/-2^30) */
#define DFSDM_DATA_MAX BIT(30)
/*
* Data are output as two's complement data in a 24 bit field.
* Data from filters are in the range +/-2^(n-1)
* 2^(n-1) maximum positive value cannot be coded in 2's complement n bits
* An extra bit is required to avoid wrap-around of the binary code for 2^(n-1)
* So, the resolution of samples from filter is actually limited to 23 bits
*/
#define DFSDM_DATA_RES 24
/* Filter configuration */
#define DFSDM_CR1_CFG_MASK (DFSDM_CR1_RCH_MASK | DFSDM_CR1_RCONT_MASK | \
DFSDM_CR1_RSYNC_MASK | DFSDM_CR1_JSYNC_MASK | \
DFSDM_CR1_JSCAN_MASK)
enum sd_converter_type {
DFSDM_AUDIO,
DFSDM_IIO,
};
struct stm32_dfsdm_dev_data {
int type;
int (*init)(struct device *dev, 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;
unsigned int nconv;
unsigned long smask;
/* ADC specific */
unsigned int oversamp;
struct iio_hw_consumer *hwc;
struct iio_backend **backend;
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;
}
/**
* struct stm32_dfsdm_trig_info - DFSDM trigger info
* @name: name of the trigger, corresponding to its source
* @jextsel: trigger signal selection
*/
struct stm32_dfsdm_trig_info {
const char *name;
unsigned int jextsel;
};
/* hardware injected trigger enable, edge selection */
enum stm32_dfsdm_jexten {
STM32_DFSDM_JEXTEN_DISABLED,
STM32_DFSDM_JEXTEN_RISING_EDGE,
STM32_DFSDM_JEXTEN_FALLING_EDGE,
STM32_DFSDM_EXTEN_BOTH_EDGES,
};
static const struct stm32_dfsdm_trig_info stm32_dfsdm_trigs[] = {
{ TIM1_TRGO, 0 },
{ TIM1_TRGO2, 1 },
{ TIM8_TRGO, 2 },
{ TIM8_TRGO2, 3 },
{ TIM3_TRGO, 4 },
{ TIM4_TRGO, 5 },
{ TIM16_OC1, 6 },
{ TIM6_TRGO, 7 },
{ TIM7_TRGO, 8 },
{ LPTIM1_OUT, 26 },
{ LPTIM2_OUT, 27 },
{ LPTIM3_OUT, 28 },
{},
};
static int stm32_dfsdm_get_jextsel(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
int i;
/* lookup triggers registered by stm32 timer trigger driver */
for (i = 0; stm32_dfsdm_trigs[i].name; i++) {
/**
* Checking both stm32 timer trigger type and trig name
* should be safe against arbitrary trigger names.
*/
if ((is_stm32_timer_trigger(trig) ||
is_stm32_lptim_trigger(trig)) &&
!strcmp(stm32_dfsdm_trigs[i].name, trig->name)) {
return stm32_dfsdm_trigs[i].jextsel;
}
}
return -EINVAL;
}
static int stm32_dfsdm_compute_osrs(struct stm32_dfsdm_filter *fl,
unsigned int fast, unsigned int oversamp)
{
unsigned int i, d, fosr, iosr;
u64 res, max;
int bits, shift;
unsigned int m = 1; /* multiplication factor */
unsigned int p = fl->ford; /* filter order (ford) */
struct stm32_dfsdm_filter_osr *flo = &fl->flo[fast];
pr_debug("Requested oversampling: %d\n", 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 maximize data output resolution.
*/
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_DATA_MAX)
break;
}
if (res > DFSDM_DATA_MAX)
continue;
res = res * (u64)m * (u64)iosr;
if (res > DFSDM_DATA_MAX)
continue;
if (res >= flo->res) {
flo->res = res;
flo->fosr = fosr;
flo->iosr = iosr;
bits = fls(flo->res);
/* 8 LBSs in data register contain chan info */
max = flo->res << 8;
/* if resolution is not a power of two */
if (flo->res > BIT(bits - 1))
bits++;
else
max--;
shift = DFSDM_DATA_RES - bits;
/*
* Compute right/left shift
* Right shift is performed by hardware
* when transferring samples to data register.
* Left shift is done by software on buffer
*/
if (shift > 0) {
/* Resolution is lower than 24 bits */
flo->rshift = 0;
flo->lshift = shift;
} else {
/*
* If resolution is 24 bits or more,
* max positive value may be ambiguous
* (equal to max negative value as sign
* bit is dropped).
* Reduce resolution to 23 bits (rshift)
* to keep the sign on bit 23 and treat
* saturation before rescaling on 24
* bits (lshift).
*/
flo->rshift = 1 - shift;
flo->lshift = 1;
max >>= flo->rshift;
}
flo->max = (s32)max;
flo->bits = bits;
pr_debug("fast %d, fosr %d, iosr %d, res 0x%llx/%d bits, rshift %d, lshift %d\n",
fast, flo->fosr, flo->iosr,
flo->res, bits, flo->rshift,
flo->lshift);
}
}
}
if (!flo->res)
return -EINVAL;
return 0;
}
static int stm32_dfsdm_compute_all_osrs(struct iio_dev *indio_dev,
unsigned int oversamp)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
int ret0, ret1;
memset(&fl->flo[0], 0, sizeof(fl->flo[0]));
memset(&fl->flo[1], 0, sizeof(fl->flo[1]));
ret0 = stm32_dfsdm_compute_osrs(fl, 0, oversamp);
ret1 = stm32_dfsdm_compute_osrs(fl, 1, oversamp);
if (ret0 < 0 && ret1 < 0) {
dev_err(&indio_dev->dev,
"Filter parameters not found: errors %d/%d\n",
ret0, ret1);
return -EINVAL;
}
return 0;
}
static int stm32_dfsdm_start_channel(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
const struct iio_chan_spec *chan;
unsigned int bit;
int ret;
for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
chan = indio_dev->channels + bit;
ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
DFSDM_CHCFGR1_CHEN_MASK,
DFSDM_CHCFGR1_CHEN(1));
if (ret < 0)
return ret;
}
return 0;
}
static void stm32_dfsdm_stop_channel(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
const struct iio_chan_spec *chan;
unsigned int bit;
for_each_set_bit(bit, &adc->smask, sizeof(adc->smask) * BITS_PER_BYTE) {
chan = indio_dev->channels + bit;
regmap_update_bits(regmap, DFSDM_CHCFGR1(chan->channel),
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_adc *adc,
unsigned int fl_id,
struct iio_trigger *trig)
{
struct stm32_dfsdm *dfsdm = adc->dfsdm;
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;
/* Nothing more to do for injected (scan mode/triggered) conversions */
if (adc->nconv > 1 || trig)
return 0;
/* Software start (single or continuous) regular 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_set_trig(struct iio_dev *indio_dev,
unsigned int fl_id,
struct iio_trigger *trig)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
u32 jextsel = 0, jexten = STM32_DFSDM_JEXTEN_DISABLED;
int ret;
if (trig) {
ret = stm32_dfsdm_get_jextsel(indio_dev, trig);
if (ret < 0)
return ret;
/* set trigger source and polarity (default to rising edge) */
jextsel = ret;
jexten = STM32_DFSDM_JEXTEN_RISING_EDGE;
}
ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_JEXTSEL_MASK | DFSDM_CR1_JEXTEN_MASK,
DFSDM_CR1_JEXTSEL(jextsel) |
DFSDM_CR1_JEXTEN(jexten));
if (ret < 0)
return ret;
return 0;
}
static int stm32_dfsdm_channels_configure(struct iio_dev *indio_dev,
unsigned int fl_id,
struct iio_trigger *trig)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo[0];
const struct iio_chan_spec *chan;
unsigned int bit;
int ret;
fl->fast = 0;
/*
* In continuous mode, use fast mode configuration,
* if it provides a better resolution.
*/
if (adc->nconv == 1 && !trig && iio_buffer_enabled(indio_dev)) {
if (fl->flo[1].res >= fl->flo[0].res) {
fl->fast = 1;
flo = &fl->flo[1];
}
}
if (!flo->res)
return -EINVAL;
dev_dbg(&indio_dev->dev, "Samples actual resolution: %d bits",
min(flo->bits, (u32)DFSDM_DATA_RES - 1));
for_each_set_bit(bit, &adc->smask,
sizeof(adc->smask) * BITS_PER_BYTE) {
chan = indio_dev->channels + bit;
ret = regmap_update_bits(regmap,
DFSDM_CHCFGR2(chan->channel),
DFSDM_CHCFGR2_DTRBS_MASK,
DFSDM_CHCFGR2_DTRBS(flo->rshift));
if (ret)
return ret;
}
return 0;
}
static int stm32_dfsdm_filter_configure(struct iio_dev *indio_dev,
unsigned int fl_id,
struct iio_trigger *trig)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
u32 cr1;
const struct iio_chan_spec *chan;
unsigned int bit, jchg = 0;
int ret;
/* Average integrator oversampling */
ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
DFSDM_FCR_IOSR(flo->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(flo->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;
ret = stm32_dfsdm_filter_set_trig(indio_dev, fl_id, trig);
if (ret)
return ret;
ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id),
DFSDM_CR1_FAST_MASK,
DFSDM_CR1_FAST(fl->fast));
if (ret)
return ret;
/*
* DFSDM modes configuration W.R.T audio/iio type modes
* ----------------------------------------------------------------
* Modes | regular | regular | injected | injected |
* | | continuous | | + scan |
* --------------|---------|--------------|----------|------------|
* single conv | x | | | |
* (1 chan) | | | | |
* --------------|---------|--------------|----------|------------|
* 1 Audio chan | | sample freq | | |
* | | or sync_mode | | |
* --------------|---------|--------------|----------|------------|
* 1 IIO chan | | sample freq | trigger | |
* | | or sync_mode | | |
* --------------|---------|--------------|----------|------------|
* 2+ IIO chans | | | | trigger or |
* | | | | sync_mode |
* ----------------------------------------------------------------
*/
if (adc->nconv == 1 && !trig) {
bit = __ffs(adc->smask);
chan = indio_dev->channels + bit;
/* Use regular conversion for single channel without trigger */
cr1 = DFSDM_CR1_RCH(chan->channel);
/* Continuous conversions triggered by SPI clk in buffer mode */
if (iio_buffer_enabled(indio_dev))
cr1 |= DFSDM_CR1_RCONT(1);
cr1 |= DFSDM_CR1_RSYNC(fl->sync_mode);
} else {
/* Use injected conversion for multiple channels */
for_each_set_bit(bit, &adc->smask,
sizeof(adc->smask) * BITS_PER_BYTE) {
chan = indio_dev->channels + bit;
jchg |= BIT(chan->channel);
}
ret = regmap_write(regmap, DFSDM_JCHGR(fl_id), jchg);
if (ret < 0)
return ret;
/* Use scan mode for multiple channels */
cr1 = DFSDM_CR1_JSCAN((adc->nconv > 1) ? 1 : 0);
/*
* Continuous conversions not supported in injected mode,
* either use:
* - conversions in sync with filter 0
* - triggered conversions
*/
if (!fl->sync_mode && !trig)
return -EINVAL;
cr1 |= DFSDM_CR1_JSYNC(fl->sync_mode);
}
return regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_CFG_MASK,
cr1);
}
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 int stm32_dfsdm_generic_channel_parse_of(struct stm32_dfsdm *dfsdm,
struct iio_dev *indio_dev,
struct iio_chan_spec *ch,
struct fwnode_handle *node)
{
struct stm32_dfsdm_channel *df_ch;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct iio_backend *backend;
const char *of_str;
int ret, val;
ret = fwnode_property_read_u32(node, "reg", &ch->channel);
if (ret < 0) {
dev_err(&indio_dev->dev, "Missing channel index %d\n", ret);
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 = fwnode_property_read_string(node, "label", &ch->datasheet_name);
if (ret < 0) {
dev_err(&indio_dev->dev,
" Error parsing 'label' for idx %d\n", ch->channel);
return ret;
}
df_ch = &dfsdm->ch_list[ch->channel];
df_ch->id = ch->channel;
ret = fwnode_property_read_string(node, "st,adc-channel-type", &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 = fwnode_property_read_string(node, "st,adc-channel-clk-src", &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 = fwnode_property_read_u32(node, "st,adc-alt-channel", &df_ch->alt_si);
if (ret != -EINVAL)
df_ch->alt_si = 0;
if (adc->dev_data->type == DFSDM_IIO) {
backend = devm_iio_backend_fwnode_get(&indio_dev->dev, NULL, node);
if (IS_ERR(backend))
return dev_err_probe(&indio_dev->dev, PTR_ERR(backend),
"Failed to get backend\n");
adc->backend[ch->scan_index] = backend;
}
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 int dfsdm_adc_set_samp_freq(struct iio_dev *indio_dev,
unsigned int sample_freq,
unsigned int spi_freq)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
unsigned int oversamp;
int ret;
oversamp = DIV_ROUND_CLOSEST(spi_freq, sample_freq);
if (spi_freq % sample_freq)
dev_dbg(&indio_dev->dev,
"Rate not accurate. requested (%u), actual (%u)\n",
sample_freq, spi_freq / oversamp);
ret = stm32_dfsdm_compute_all_osrs(indio_dev, oversamp);
if (ret < 0)
return ret;
adc->sample_freq = spi_freq / oversamp;
adc->oversamp = oversamp;
return 0;
}
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_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) {
ret = dfsdm_adc_set_samp_freq(indio_dev, sample_freq, spi_freq);
if (ret < 0)
return ret;
}
adc->spi_freq = spi_freq;
return len;
}
static int stm32_dfsdm_start_conv(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
int ret;
ret = stm32_dfsdm_channels_configure(indio_dev, adc->fl_id, trig);
if (ret < 0)
return ret;
ret = stm32_dfsdm_start_channel(indio_dev);
if (ret < 0)
return ret;
ret = stm32_dfsdm_filter_configure(indio_dev, adc->fl_id, trig);
if (ret < 0)
goto stop_channels;
ret = stm32_dfsdm_start_filter(adc, adc->fl_id, trig);
if (ret < 0)
goto filter_unconfigure;
return 0;
filter_unconfigure:
regmap_clear_bits(regmap, DFSDM_CR1(adc->fl_id), DFSDM_CR1_CFG_MASK);
stop_channels:
stm32_dfsdm_stop_channel(indio_dev);
return ret;
}
static void stm32_dfsdm_stop_conv(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
struct regmap *regmap = adc->dfsdm->regmap;
stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
regmap_clear_bits(regmap, DFSDM_CR1(adc->fl_id), DFSDM_CR1_CFG_MASK);
stm32_dfsdm_stop_channel(indio_dev);
}
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;
unsigned int rx_buf_sz = DFSDM_DMA_BUFFER_SIZE;
/*
* 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 = min(rx_buf_sz, watermark * 2 * adc->nconv);
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 inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc,
s32 *buffer)
{
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
unsigned int i = adc->nconv;
s32 *ptr = buffer;
while (i--) {
/* Mask 8 LSB that contains the channel ID */
*ptr &= 0xFFFFFF00;
/* Convert 2^(n-1) sample to 2^(n-1)-1 to avoid wrap-around */
if (*ptr > flo->max)
*ptr -= 1;
/*
* Samples from filter are retrieved with 23 bits resolution
* or less. Shift left to align MSB on 24 bits.
*/
*ptr <<= flo->lshift;
ptr++;
}
}
static void stm32_dfsdm_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, "pos = %d, available = %d\n",
adc->bufi, available);
old_pos = adc->bufi;
while (available >= indio_dev->scan_bytes) {
s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi];
stm32_dfsdm_process_data(adc, buffer);
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;
}
/*
* In DMA mode the trigger services of IIO are not used
* (e.g. no call to iio_trigger_poll).
* Calling irq handler associated to the hardware trigger is not
* relevant as the conversions have already been done. Data
* transfers are performed directly in DMA callback instead.
* This implementation avoids to call trigger irq handler that
* may sleep, in an atomic context (DMA irq handler context).
*/
if (adc->dev_data->type == DFSDM_IIO)
iio_push_to_buffers(indio_dev, buffer);
}
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);
/*
* The DFSDM supports half-word transfers. However, for 16 bits record,
* 4 bytes buswidth is kept, to avoid losing samples LSBs when left
* shift is required.
*/
struct dma_slave_config config = {
.src_addr = (dma_addr_t)adc->dfsdm->phys_base,
.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
};
struct dma_async_tx_descriptor *desc;
dma_cookie_t cookie;
int ret;
if (!adc->dma_chan)
return -EINVAL;
dev_dbg(&indio_dev->dev, "size=%d watermark=%d\n",
adc->buf_sz, adc->buf_sz / 2);
if (adc->nconv == 1 && !indio_dev->trig)
config.src_addr += DFSDM_RDATAR(adc->fl_id);
else
config.src_addr += DFSDM_JDATAR(adc->fl_id);
ret = dmaengine_slave_config(adc->dma_chan, &config);
if (ret)
return ret;
/* 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_dma_buffer_done;
desc->callback_param = indio_dev;
cookie = dmaengine_submit(desc);
ret = dma_submit_error(cookie);
if (ret)
goto err_stop_dma;
/* Issue pending DMA requests */
dma_async_issue_pending(adc->dma_chan);
if (adc->nconv == 1 && !indio_dev->trig) {
/* Enable regular DMA transfer*/
ret = regmap_set_bits(adc->dfsdm->regmap,
DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RDMAEN_MASK);
} else {
/* Enable injected DMA transfer*/
ret = regmap_set_bits(adc->dfsdm->regmap,
DFSDM_CR1(adc->fl_id),
DFSDM_CR1_JDMAEN_MASK);
}
if (ret < 0)
goto err_stop_dma;
return 0;
err_stop_dma:
dmaengine_terminate_all(adc->dma_chan);
return ret;
}
static void stm32_dfsdm_adc_dma_stop(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
if (!adc->dma_chan)
return;
regmap_clear_bits(adc->dfsdm->regmap, DFSDM_CR1(adc->fl_id),
DFSDM_CR1_RDMAEN_MASK | DFSDM_CR1_JDMAEN_MASK);
dmaengine_terminate_all(adc->dma_chan);
}
static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
adc->nconv = bitmap_weight(scan_mask, iio_get_masklength(indio_dev));
adc->smask = *scan_mask;
dev_dbg(&indio_dev->dev, "nconv=%d mask=%lx\n", adc->nconv, *scan_mask);
return 0;
}
static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int i = 0;
int ret;
/* Reset adc buffer index */
adc->bufi = 0;
if (adc->hwc) {
ret = iio_hw_consumer_enable(adc->hwc);
if (ret < 0)
return ret;
}
if (adc->backend) {
while (adc->backend[i]) {
ret = iio_backend_enable(adc->backend[i]);
if (ret < 0)
return ret;
i++;
}
}
ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
if (ret < 0)
goto err_stop_hwc;
ret = stm32_dfsdm_adc_dma_start(indio_dev);
if (ret) {
dev_err(&indio_dev->dev, "Can't start DMA\n");
goto stop_dfsdm;
}
ret = stm32_dfsdm_start_conv(indio_dev, indio_dev->trig);
if (ret) {
dev_err(&indio_dev->dev, "Can't start conversion\n");
goto err_stop_dma;
}
return 0;
err_stop_dma:
stm32_dfsdm_adc_dma_stop(indio_dev);
stop_dfsdm:
stm32_dfsdm_stop_dfsdm(adc->dfsdm);
err_stop_hwc:
if (adc->hwc)
iio_hw_consumer_disable(adc->hwc);
return ret;
}
static int stm32_dfsdm_predisable(struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int i = 0;
stm32_dfsdm_stop_conv(indio_dev);
stm32_dfsdm_adc_dma_stop(indio_dev);
stm32_dfsdm_stop_dfsdm(adc->dfsdm);
if (adc->backend) {
while (adc->backend[i]) {
iio_backend_disable(adc->backend[i]);
i++;
}
}
if (adc->hwc)
iio_hw_consumer_disable(adc->hwc);
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 time_left;
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;
adc->nconv = 1;
adc->smask = BIT(chan->scan_index);
ret = stm32_dfsdm_start_conv(indio_dev, NULL);
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;
}
time_left = 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 (time_left == 0)
ret = -ETIMEDOUT;
else if (time_left < 0)
ret = time_left;
else
ret = IIO_VAL_INT;
stm32_dfsdm_stop_conv(indio_dev);
stm32_dfsdm_process_data(adc, res);
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_channel *ch = &adc->dfsdm->ch_list[chan->channel];
unsigned int spi_freq;
int ret = -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;
}
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = stm32_dfsdm_compute_all_osrs(indio_dev, val);
if (!ret) {
dev_dbg(&indio_dev->dev,
"Sampling rate changed from (%u) to (%u)\n",
adc->sample_freq, spi_freq / val);
adc->oversamp = val;
adc->sample_freq = spi_freq / val;
}
iio_device_release_direct_mode(indio_dev);
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
if (!val)
return -EINVAL;
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = dfsdm_adc_set_samp_freq(indio_dev, val, spi_freq);
iio_device_release_direct_mode(indio_dev);
return ret;
}
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);
struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
struct stm32_dfsdm_filter_osr *flo = &fl->flo[fl->fast];
u32 max = flo->max << (flo->lshift - chan->scan_type.shift);
int idx = chan->scan_index;
int ret;
if (flo->lshift < chan->scan_type.shift)
max = flo->max >> (chan->scan_type.shift - flo->lshift);
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
if (adc->hwc)
ret = iio_hw_consumer_enable(adc->hwc);
if (adc->backend)
ret = iio_backend_enable(adc->backend[idx]);
if (ret < 0) {
dev_err(&indio_dev->dev,
"%s: IIO enable failed (channel %d)\n",
__func__, chan->channel);
iio_device_release_direct_mode(indio_dev);
return ret;
}
ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
if (adc->hwc)
iio_hw_consumer_disable(adc->hwc);
if (adc->backend)
iio_backend_disable(adc->backend[idx]);
if (ret < 0) {
dev_err(&indio_dev->dev,
"%s: Conversion failed (channel %d)\n",
__func__, chan->channel);
iio_device_release_direct_mode(indio_dev);
return ret;
}
iio_device_release_direct_mode(indio_dev);
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;
case IIO_CHAN_INFO_SCALE:
/*
* Scale is expressed in mV.
* When fast mode is disabled, actual resolution may be lower
* than 2^n, where n = realbits - 1.
* This leads to underestimating the input voltage.
* To compensate this deviation, the voltage reference can be
* corrected with a factor = realbits resolution / actual max
*/
if (adc->backend) {
ret = iio_backend_read_scale(adc->backend[idx], chan, val, NULL);
if (ret < 0)
return ret;
*val = div_u64((u64)*val * (u64)BIT(DFSDM_DATA_RES - 1), max);
*val2 = chan->scan_type.realbits;
if (chan->differential)
*val *= 2;
}
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
/*
* DFSDM output data are in the range [-2^n, 2^n],
* with n = realbits - 1.
* - Differential modulator:
* Offset correspond to SD modulator offset.
* - Single ended modulator:
* Input is in [0V, Vref] range,
* where 0V corresponds to -2^n, and Vref to 2^n.
* Add 2^n to offset. (i.e. middle of input range)
* offset = offset(sd) * vref / res(sd) * max / vref.
*/
if (adc->backend) {
ret = iio_backend_read_offset(adc->backend[idx], chan, val, NULL);
if (ret < 0)
return ret;
*val = div_u64((u64)max * *val, BIT(*val2 - 1));
if (!chan->differential)
*val += max;
}
return IIO_VAL_INT;
}
return -EINVAL;
}
static int stm32_dfsdm_validate_trigger(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
return stm32_dfsdm_get_jextsel(indio_dev, trig) < 0 ? -EINVAL : 0;
}
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,
.update_scan_mode = stm32_dfsdm_update_scan_mode,
};
static const struct iio_info stm32_dfsdm_info_adc = {
.hwfifo_set_watermark = stm32_dfsdm_set_watermark,
.read_raw = stm32_dfsdm_read_raw,
.write_raw = stm32_dfsdm_write_raw,
.update_scan_mode = stm32_dfsdm_update_scan_mode,
.validate_trigger = stm32_dfsdm_validate_trigger,
};
static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
{
struct iio_dev *indio_dev = arg;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
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_set_bits(regmap, DFSDM_ICR(adc->fl_id),
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 device *dev,
struct iio_dev *indio_dev)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
adc->dma_chan = dma_request_chan(dev, "rx");
if (IS_ERR(adc->dma_chan)) {
int ret = PTR_ERR(adc->dma_chan);
adc->dma_chan = NULL;
return ret;
}
adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
DFSDM_DMA_BUFFER_SIZE,
&adc->dma_buf, GFP_KERNEL);
if (!adc->rx_buf) {
dma_release_channel(adc->dma_chan);
return -ENOMEM;
}
indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
indio_dev->setup_ops = &stm32_dfsdm_buffer_setup_ops;
return 0;
}
static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev, struct iio_chan_spec *ch,
struct fwnode_handle *child)
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int ret;
if (child)
ret = stm32_dfsdm_generic_channel_parse_of(adc->dfsdm, indio_dev, ch, child);
else /* Legacy binding */
ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
if (ret < 0)
return dev_err_probe(&indio_dev->dev, ret, "Failed to parse channel\n");
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
*/
if (child) {
ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET);
} else {
/* Legacy. Scaling not supported */
ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
}
ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) |
BIT(IIO_CHAN_INFO_SAMP_FREQ);
if (adc->dev_data->type == DFSDM_AUDIO) {
ch->ext_info = dfsdm_adc_audio_ext_info;
ch->scan_index = 0;
} else {
ch->scan_type.shift = 8;
}
ch->scan_type.sign = 's';
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_chan_init(struct iio_dev *indio_dev, struct iio_chan_spec *channels)
{
int num_ch = indio_dev->num_channels;
int chan_idx = 0;
int ret;
for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
channels[chan_idx].scan_index = chan_idx;
ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &channels[chan_idx], NULL);
if (ret < 0)
return dev_err_probe(&indio_dev->dev, ret, "Channels init failed\n");
}
return 0;
}
static int stm32_dfsdm_generic_chan_init(struct iio_dev *indio_dev, struct iio_chan_spec *channels)
{
int chan_idx = 0, ret;
device_for_each_child_node_scoped(&indio_dev->dev, child) {
/* Skip DAI node in DFSDM audio nodes */
if (fwnode_property_present(child, "compatible"))
continue;
channels[chan_idx].scan_index = chan_idx;
ret = stm32_dfsdm_adc_chan_init_one(indio_dev, &channels[chan_idx], child);
if (ret < 0)
return dev_err_probe(&indio_dev->dev, ret, "Channels init failed\n");
chan_idx++;
}
return chan_idx;
}
static int stm32_dfsdm_audio_init(struct device *dev, 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;
bool legacy = false;
int num_ch, ret;
/* If st,adc-channels is defined legacy binding is used. Else assume generic binding. */
num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, "st,adc-channels");
if (num_ch == 1)
legacy = true;
ch = devm_kzalloc(&indio_dev->dev, sizeof(*ch), GFP_KERNEL);
if (!ch)
return -ENOMEM;
indio_dev->num_channels = 1;
indio_dev->channels = ch;
if (legacy)
ret = stm32_dfsdm_chan_init(indio_dev, ch);
else
ret = stm32_dfsdm_generic_chan_init(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;
return stm32_dfsdm_dma_request(dev, indio_dev);
}
static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev)
{
struct iio_chan_spec *ch;
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
int num_ch, ret;
bool legacy = false;
adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
ret = stm32_dfsdm_compute_all_osrs(indio_dev, adc->oversamp);
if (ret < 0)
return ret;
num_ch = device_get_child_node_count(&indio_dev->dev);
if (!num_ch) {
/* No channels nodes found. Assume legacy binding */
num_ch = of_property_count_u32_elems(indio_dev->dev.of_node, "st,adc-channels");
if (num_ch < 0) {
dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
return num_ch;
}
legacy = true;
}
if (num_ch > adc->dfsdm->num_chs) {
dev_err(&indio_dev->dev, "Number of channel [%d] exceeds [%d]\n",
num_ch, adc->dfsdm->num_chs);
return -EINVAL;
}
indio_dev->num_channels = num_ch;
if (legacy) {
/* Bind to SD modulator IIO device. */
adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
if (IS_ERR(adc->hwc))
return dev_err_probe(&indio_dev->dev, -EPROBE_DEFER,
"waiting for SD modulator\n");
} else {
/* Generic binding. SD modulator IIO device not used. Use SD modulator backend. */
adc->hwc = NULL;
adc->backend = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*adc->backend),
GFP_KERNEL);
if (!adc->backend)
return -ENOMEM;
}
ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch), GFP_KERNEL);
if (!ch)
return -ENOMEM;
indio_dev->channels = ch;
if (legacy)
ret = stm32_dfsdm_chan_init(indio_dev, ch);
else
ret = stm32_dfsdm_generic_chan_init(indio_dev, ch);
if (ret < 0)
return ret;
init_completion(&adc->completion);
/* Optionally request DMA */
ret = stm32_dfsdm_dma_request(dev, indio_dev);
if (ret) {
if (ret != -ENODEV)
return dev_err_probe(dev, ret,
"DMA channel request failed with\n");
dev_dbg(dev, "No DMA support\n");
return 0;
}
ret = iio_triggered_buffer_setup(indio_dev,
&iio_pollfunc_store_time, NULL,
&stm32_dfsdm_buffer_setup_ops);
if (ret) {
stm32_dfsdm_dma_release(indio_dev);
dev_err(&indio_dev->dev, "buffer setup failed\n");
return ret;
}
/* lptimer/timer hardware triggers */
indio_dev->modes |= INDIO_HARDWARE_TRIGGERED;
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,
},
{}
};
MODULE_DEVICE_TABLE(of, stm32_dfsdm_adc_match);
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.of_node = np;
iio->modes = INDIO_DIRECT_MODE;
platform_set_drvdata(pdev, iio);
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);
if (irq < 0)
return irq;
ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
0, pdev->name, iio);
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(dev, 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 void stm32_dfsdm_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
if (adc->dev_data->type == DFSDM_AUDIO)
of_platform_depopulate(&pdev->dev);
iio_device_unregister(indio_dev);
stm32_dfsdm_dma_release(indio_dev);
}
static int stm32_dfsdm_adc_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
if (iio_buffer_enabled(indio_dev))
stm32_dfsdm_predisable(indio_dev);
return 0;
}
static int stm32_dfsdm_adc_resume(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
const struct iio_chan_spec *chan;
struct stm32_dfsdm_channel *ch;
int i, ret;
/* restore channels configuration */
for (i = 0; i < indio_dev->num_channels; i++) {
chan = indio_dev->channels + i;
ch = &adc->dfsdm->ch_list[chan->channel];
ret = stm32_dfsdm_chan_configure(adc->dfsdm, ch);
if (ret)
return ret;
}
if (iio_buffer_enabled(indio_dev))
stm32_dfsdm_postenable(indio_dev);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(stm32_dfsdm_adc_pm_ops,
stm32_dfsdm_adc_suspend,
stm32_dfsdm_adc_resume);
static struct platform_driver stm32_dfsdm_adc_driver = {
.driver = {
.name = "stm32-dfsdm-adc",
.of_match_table = stm32_dfsdm_adc_match,
.pm = pm_sleep_ptr(&stm32_dfsdm_adc_pm_ops),
},
.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");
MODULE_IMPORT_NS("IIO_BACKEND");