[PATCH v9 2/2] iio: accel: adxl355: Add triggered buffer support
From: Puranjay Mohan
Date: Mon Aug 09 2021 - 03:45:50 EST
Provide a way for continuous data capture by setting up buffer support. The
data ready signal exposed at the DRDY pin of the ADXL355 is exploited as
a hardware interrupt which triggers to fill the buffer.
Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
---
drivers/iio/accel/Kconfig | 4 ++
drivers/iio/accel/adxl355.h | 2 +-
drivers/iio/accel/adxl355_core.c | 102 ++++++++++++++++++++++++++++++-
drivers/iio/accel/adxl355_i2c.c | 3 +-
drivers/iio/accel/adxl355_spi.c | 2 +-
5 files changed, 108 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index d0c45c809..9c16c1841 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -69,6 +69,8 @@ config ADXL355_I2C
depends on I2C
select ADXL355
select REGMAP_I2C
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say Y here if you want to build i2c support for the Analog Devices
ADXL355 3-axis digital accelerometer.
@@ -82,6 +84,8 @@ config ADXL355_SPI
depends on SPI
select ADXL355
select REGMAP_SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say Y here if you want to build spi support for the Analog Devices
ADXL355 3-axis digital accelerometer.
diff --git a/drivers/iio/accel/adxl355.h b/drivers/iio/accel/adxl355.h
index 322b0abb8..f0a376e6d 100644
--- a/drivers/iio/accel/adxl355.h
+++ b/drivers/iio/accel/adxl355.h
@@ -15,5 +15,5 @@ extern const struct regmap_access_table adxl355_readable_regs_tbl;
extern const struct regmap_access_table adxl355_writeable_regs_tbl;
int adxl355_core_probe(struct device *dev, struct regmap *regmap,
- const char *name);
+ const char *name, int irq);
#endif /* _ADXL355_H_ */
diff --git a/drivers/iio/accel/adxl355_core.c b/drivers/iio/accel/adxl355_core.c
index d1163cde1..45397dcce 100644
--- a/drivers/iio/accel/adxl355_core.c
+++ b/drivers/iio/accel/adxl355_core.c
@@ -9,6 +9,10 @@
#include <asm/unaligned.h>
#include <linux/bitfield.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
#include <linux/iio/iio.h>
#include <linux/limits.h>
#include <linux/math64.h>
@@ -153,6 +157,7 @@ static const struct adxl355_chan_info adxl355_chans[] = {
};
struct adxl355_data {
+ int irq;
struct regmap *regmap;
struct device *dev;
struct mutex lock; /* lock to protect op_mode */
@@ -162,6 +167,12 @@ struct adxl355_data {
int calibbias[3];
int adxl355_hpf_3db_table[7][2];
u8 transf_buf[3] ____cacheline_aligned;
+ struct iio_trigger *dready_trig;
+ /* Ensure correct alignment of timestamp when present */
+ struct {
+ __be32 channels[3];
+ s64 ts;
+ } buffer ____cacheline_aligned;
};
static int adxl355_set_op_mode(struct adxl355_data *data,
@@ -493,12 +504,46 @@ static int adxl355_read_avail(struct iio_dev *indio_dev,
}
}
+static const unsigned long adxl355_avail_scan_masks[] = {
+ GENMASK(3, 0),
+ 0
+};
+
static const struct iio_info adxl355_info = {
.read_raw = adxl355_read_raw,
.write_raw = adxl355_write_raw,
.read_avail = &adxl355_read_avail
};
+static const struct iio_trigger_ops adxl355_trigger_ops = {
+ .validate_device = &iio_trigger_validate_own_device,
+};
+
+static irqreturn_t adxl355_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adxl355_data *data = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&data->lock);
+
+ ret = regmap_bulk_read(data->regmap, ADXL355_XDATA3_REG,
+ data->buffer.channels,
+ 9);
+ if (ret)
+ goto out_unlock_notify;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
+ pf->timestamp);
+
+out_unlock_notify:
+ mutex_unlock(&data->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
#define ADXL355_ACCEL_CHANNEL(index, reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
@@ -512,6 +557,7 @@ static const struct iio_info adxl355_info = {
.info_mask_shared_by_type_available = \
BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \
+ .scan_index = index, \
.scan_type = { \
.sign = 's', \
.realbits = 20, \
@@ -531,17 +577,56 @@ static const struct iio_chan_spec adxl355_channels[] = {
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = 3,
.scan_type = {
.sign = 's',
.realbits = 12,
.storagebits = 16,
.endianness = IIO_BE,
},
- }
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(4)
};
+static int adxl355_probe_trigger(struct iio_dev *indio_dev)
+{
+ struct adxl355_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (!data->irq) {
+ dev_info(data->dev, "no irq, using polling\n");
+ return 0;
+ }
+
+ data->dready_trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (!data->dready_trig)
+ return -ENOMEM;
+
+ data->dready_trig->ops = &adxl355_trigger_ops;
+ iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+
+ ret = devm_request_irq(data->dev, data->irq,
+ &iio_trigger_generic_data_rdy_poll,
+ IRQF_ONESHOT, "adxl355_irq", data->dready_trig);
+ if (ret < 0)
+ return dev_err_probe(data->dev, ret, "request irq %d failed\n",
+ data->irq);
+
+ ret = devm_iio_trigger_register(data->dev, data->dready_trig);
+ if (ret) {
+ dev_err(data->dev, "iio trigger register failed\n");
+ return ret;
+ }
+
+ indio_dev->trig = iio_trigger_get(data->dready_trig);
+
+ return 0;
+}
+
int adxl355_core_probe(struct device *dev, struct regmap *regmap,
- const char *name)
+ const char *name, int irq)
{
struct adxl355_data *data;
struct iio_dev *indio_dev;
@@ -554,6 +639,7 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap,
data = iio_priv(indio_dev);
data->regmap = regmap;
data->dev = dev;
+ data->irq = irq;
data->op_mode = ADXL355_STANDBY;
mutex_init(&data->lock);
@@ -562,6 +648,7 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap,
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = adxl355_channels;
indio_dev->num_channels = ARRAY_SIZE(adxl355_channels);
+ indio_dev->available_scan_masks = adxl355_avail_scan_masks;
ret = adxl355_setup(data);
if (ret < 0) {
@@ -569,6 +656,17 @@ int adxl355_core_probe(struct device *dev, struct regmap *regmap,
return ret;
}
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ &iio_pollfunc_store_time,
+ &adxl355_trigger_handler, NULL);
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "iio triggered buffer setup failed\n");
+
+ ret = adxl355_probe_trigger(indio_dev);
+ if (ret < 0)
+ return ret;
+
return devm_iio_device_register(dev, indio_dev);
}
EXPORT_SYMBOL_GPL(adxl355_core_probe);
diff --git a/drivers/iio/accel/adxl355_i2c.c b/drivers/iio/accel/adxl355_i2c.c
index e3070ee81..c18521819 100644
--- a/drivers/iio/accel/adxl355_i2c.c
+++ b/drivers/iio/accel/adxl355_i2c.c
@@ -31,7 +31,8 @@ static int adxl355_i2c_probe(struct i2c_client *client)
return PTR_ERR(regmap);
}
- return adxl355_core_probe(&client->dev, regmap, client->name);
+ return adxl355_core_probe(&client->dev, regmap, client->name,
+ client->irq);
}
static const struct i2c_device_id adxl355_i2c_id[] = {
diff --git a/drivers/iio/accel/adxl355_spi.c b/drivers/iio/accel/adxl355_spi.c
index a16bd1407..f9ba153f6 100644
--- a/drivers/iio/accel/adxl355_spi.c
+++ b/drivers/iio/accel/adxl355_spi.c
@@ -34,7 +34,7 @@ static int adxl355_spi_probe(struct spi_device *spi)
return PTR_ERR(regmap);
}
- return adxl355_core_probe(&spi->dev, regmap, id->name);
+ return adxl355_core_probe(&spi->dev, regmap, id->name, spi->irq);
}
static const struct spi_device_id adxl355_spi_id[] = {
--
2.30.1