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Diffstat (limited to 'drivers/iio/adc/stm32-dfsdm-adc.c')
-rw-r--r--drivers/iio/adc/stm32-dfsdm-adc.c297
1 files changed, 259 insertions, 38 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
index fabd654245f5..2037f73426d4 100644
--- a/drivers/iio/adc/stm32-dfsdm-adc.c
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -9,6 +9,7 @@
#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>
@@ -78,6 +79,7 @@ struct stm32_dfsdm_adc {
/* ADC specific */
unsigned int oversamp;
struct iio_hw_consumer *hwc;
+ struct iio_backend **backend;
struct completion completion;
u32 *buffer;
@@ -666,6 +668,74 @@ static int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
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,
@@ -987,7 +1057,7 @@ static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev,
{
struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
- adc->nconv = bitmap_weight(scan_mask, indio_dev->masklength);
+ 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);
@@ -998,6 +1068,7 @@ static int stm32_dfsdm_update_scan_mode(struct iio_dev *indio_dev,
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 */
@@ -1009,6 +1080,15 @@ static int stm32_dfsdm_postenable(struct iio_dev *indio_dev)
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;
@@ -1041,6 +1121,7 @@ err_stop_hwc:
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);
@@ -1048,6 +1129,13 @@ static int stm32_dfsdm_predisable(struct iio_dev *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);
@@ -1220,14 +1308,25 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
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;
- ret = iio_hw_consumer_enable(adc->hwc);
+ 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",
@@ -1236,7 +1335,10 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
return ret;
}
ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
- iio_hw_consumer_disable(adc->hwc);
+ 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",
@@ -1256,6 +1358,50 @@ static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
*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;
@@ -1320,7 +1466,7 @@ static const struct iio_chan_spec_ext_info dfsdm_adc_audio_ext_info[] = {
.read = dfsdm_adc_audio_get_spiclk,
.write = dfsdm_adc_audio_set_spiclk,
},
- {},
+ { }
};
static void stm32_dfsdm_dma_release(struct iio_dev *indio_dev)
@@ -1362,15 +1508,18 @@ static int stm32_dfsdm_dma_request(struct device *dev,
return 0;
}
-static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
- struct iio_chan_spec *ch)
+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;
- ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
+ 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 ret;
+ return dev_err_probe(&indio_dev->dev, ret, "Failed to parse channel\n");
ch->type = IIO_VOLTAGE;
ch->indexed = 1;
@@ -1379,12 +1528,21 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
* 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);
+ 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;
}
@@ -1396,20 +1554,67 @@ static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
&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;
- int ret;
+ 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;
- ch->scan_index = 0;
+ 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);
- ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
if (ret < 0) {
dev_err(&indio_dev->dev, "Channels init failed\n");
return ret;
@@ -1420,9 +1625,6 @@ static int stm32_dfsdm_audio_init(struct device *dev, struct iio_dev *indio_dev)
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(dev, indio_dev);
}
@@ -1430,43 +1632,61 @@ 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;
- int ret, chan_idx;
+ 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 = 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;
+ 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;
}
- /* Bind to SD modulator IIO device */
- adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
- if (IS_ERR(adc->hwc))
- return -EPROBE_DEFER;
+ 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;
- ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
- GFP_KERNEL);
- if (!ch)
- return -ENOMEM;
+ 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;
- 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;
- }
+ adc->backend = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*adc->backend),
+ GFP_KERNEL);
+ if (!adc->backend)
+ return -ENOMEM;
}
- indio_dev->num_channels = num_ch;
+ 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 */
@@ -1677,3 +1897,4 @@ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 23:41:36 +0100