[PATCH v2 1/3] iio: gyro: adxrs290: Add triggered buffer support
From: Nishant Malpani
Date: Thu Sep 03 2020 - 10:08:26 EST
Provide a way for continuous data capture by setting up buffer support. The
data ready signal exposed at the SYNC pin of the ADXRS290 is exploited as
a hardware interrupt which triggers to fill the buffer.
Triggered buffer setup was tested with both hardware trigger (DATA_RDY) and
software triggers (sysfs-trig & hrtimer).
Signed-off-by: Nishant Malpani <nish.malpani25@xxxxxxxxx>
---
Changes in v2:
- In adxrs290_set_mode(), move 'if' block outside the locked section
- use break statement for error handling instead of goto labels in
switch-case blocks
- remove outer parentheses when conditional ternary operator is used
- use dev_err_probe() saving a few lines of code
- re-align 'buffer' variable name in 'struct adxrs290_state'
- don't return errors in 'try_reenable' callback
- use 'st->spi' inline in 'adxrs290_trigger_handler'
- unnecessary to mention default 'shift' (= 0) in
iio_chan_spec.scan_type
- bring in consistent wrapping of parameters while staying under
the advised 80 chars line limit
---
drivers/iio/gyro/Kconfig | 2 +
drivers/iio/gyro/adxrs290.c | 265 ++++++++++++++++++++++++++++++++++--
2 files changed, 253 insertions(+), 14 deletions(-)
diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig
index 024a34139875..5824f2edf975 100644
--- a/drivers/iio/gyro/Kconfig
+++ b/drivers/iio/gyro/Kconfig
@@ -44,6 +44,8 @@ config ADIS16260
config ADXRS290
tristate "Analog Devices ADXRS290 Dual-Axis MEMS Gyroscope SPI driver"
depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Analog Devices ADXRS290 programmable
digital output gyroscope.
diff --git a/drivers/iio/gyro/adxrs290.c b/drivers/iio/gyro/adxrs290.c
index ff989536d2fb..4099b8917d3e 100644
--- a/drivers/iio/gyro/adxrs290.c
+++ b/drivers/iio/gyro/adxrs290.c
@@ -13,8 +13,12 @@
#include <linux/module.h>
#include <linux/spi/spi.h>
+#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
#define ADXRS290_ADI_ID 0xAD
#define ADXRS290_MEMS_ID 0x1D
@@ -35,7 +39,9 @@
#define ADXRS290_READ BIT(7)
#define ADXRS290_TSM BIT(0)
#define ADXRS290_MEASUREMENT BIT(1)
-#define ADXRS290_SYNC GENMASK(1, 0)
+#define ADXRS290_DATA_RDY_OUT BIT(0)
+#define ADXRS290_SYNC_MASK GENMASK(1, 0)
+#define ADXRS290_SYNC(x) FIELD_PREP(ADXRS290_SYNC_MASK, x)
#define ADXRS290_LPF_MASK GENMASK(2, 0)
#define ADXRS290_LPF(x) FIELD_PREP(ADXRS290_LPF_MASK, x)
#define ADXRS290_HPF_MASK GENMASK(7, 4)
@@ -50,6 +56,13 @@ enum adxrs290_mode {
ADXRS290_MODE_MEASUREMENT,
};
+enum adxrs290_scan_index {
+ ADXRS290_IDX_X,
+ ADXRS290_IDX_Y,
+ ADXRS290_IDX_TEMP,
+ ADXRS290_IDX_TS,
+};
+
struct adxrs290_state {
struct spi_device *spi;
/* Serialize reads and their subsequent processing */
@@ -57,6 +70,12 @@ struct adxrs290_state {
enum adxrs290_mode mode;
unsigned int lpf_3db_freq_idx;
unsigned int hpf_3db_freq_idx;
+ struct iio_trigger *dready_trig;
+ /* Ensure correct alignment of timestamp when present */
+ struct {
+ s16 channels[3];
+ s64 ts __aligned(8);
+ } buffer;
};
/*
@@ -192,6 +211,52 @@ static int adxrs290_set_filter_freq(struct iio_dev *indio_dev,
return adxrs290_spi_write_reg(st->spi, ADXRS290_REG_FILTER, val);
}
+static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
+{
+ struct adxrs290_state *st = iio_priv(indio_dev);
+ int val, ret;
+
+ if (st->mode == mode) {
+ ret = 0;
+ goto done;
+ }
+
+ mutex_lock(&st->lock);
+
+ ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
+ if (ret < 0)
+ goto done;
+
+ val = ret;
+
+ switch (mode) {
+ case ADXRS290_MODE_STANDBY:
+ val &= ~ADXRS290_MEASUREMENT;
+ break;
+ case ADXRS290_MODE_MEASUREMENT:
+ val |= ADXRS290_MEASUREMENT;
+ break;
+ default:
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = adxrs290_spi_write_reg(st->spi,
+ ADXRS290_REG_POWER_CTL,
+ val);
+ if (ret < 0) {
+ dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
+ goto done;
+ }
+
+ /* update cached mode */
+ st->mode = mode;
+
+done:
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
static int adxrs290_initial_setup(struct iio_dev *indio_dev)
{
struct adxrs290_state *st = iio_priv(indio_dev);
@@ -203,6 +268,13 @@ static int adxrs290_initial_setup(struct iio_dev *indio_dev)
ADXRS290_MEASUREMENT | ADXRS290_TSM);
}
+static void adxrs290_chip_off_action(void *data)
+{
+ struct iio_dev *indio_dev = data;
+
+ adxrs290_set_mode(indio_dev, ADXRS290_MODE_STANDBY);
+}
+
static int adxrs290_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
@@ -215,24 +287,34 @@ static int adxrs290_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
switch (chan->type) {
case IIO_ANGL_VEL:
ret = adxrs290_get_rate_data(indio_dev,
ADXRS290_READ_REG(chan->address),
val);
if (ret < 0)
- return ret;
+ break;
- return IIO_VAL_INT;
+ ret = IIO_VAL_INT;
+ break;
case IIO_TEMP:
ret = adxrs290_get_temp_data(indio_dev, val);
if (ret < 0)
- return ret;
+ break;
- return IIO_VAL_INT;
+ ret = IIO_VAL_INT;
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
+
+ iio_device_release_direct_mode(indio_dev);
+ return ret;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_ANGL_VEL:
@@ -279,34 +361,52 @@ static int adxrs290_write_raw(struct iio_dev *indio_dev,
long mask)
{
struct adxrs290_state *st = iio_priv(indio_dev);
- int lpf_idx, hpf_idx;
+ int ret, lpf_idx, hpf_idx;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
switch (mask) {
case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
val, val2);
- if (lpf_idx < 0)
- return -EINVAL;
+ if (lpf_idx < 0) {
+ ret = -EINVAL;
+ break;
+ }
+
/* caching the updated state of the low-pass filter */
st->lpf_3db_freq_idx = lpf_idx;
/* retrieving the current state of the high-pass filter */
hpf_idx = st->hpf_3db_freq_idx;
- return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
+ ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
+ break;
+
case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
val, val2);
- if (hpf_idx < 0)
- return -EINVAL;
+ if (hpf_idx < 0) {
+ ret = -EINVAL;
+ break;
+ }
+
/* caching the updated state of the high-pass filter */
st->hpf_3db_freq_idx = hpf_idx;
/* retrieving the current state of the low-pass filter */
lpf_idx = st->lpf_3db_freq_idx;
- return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
+ ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
}
- return -EINVAL;
+ iio_device_release_direct_mode(indio_dev);
+ return ret;
}
static int adxrs290_read_avail(struct iio_dev *indio_dev,
@@ -334,6 +434,69 @@ static int adxrs290_read_avail(struct iio_dev *indio_dev,
}
}
+static int adxrs290_data_rdy_trigger_set_state(struct iio_trigger *trig, bool state)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct adxrs290_state *st = iio_priv(indio_dev);
+ int ret;
+ u8 val;
+
+ val = state ? ADXRS290_SYNC(ADXRS290_DATA_RDY_OUT) : 0;
+
+ ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_DATA_RDY, val);
+ if (ret < 0)
+ dev_err(&st->spi->dev, "failed to start data ready interrupt\n");
+
+ return ret;
+}
+
+static int adxrs290_reset_trig(struct iio_trigger *trig)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ int val;
+
+ /*
+ * Data ready interrupt is reset after a read of the data registers.
+ * Here, we only read the 16b DATAY registers as that marks the end of
+ * a read of the data registers and initiates a reset for the interrupt line.
+ */
+ adxrs290_get_rate_data(indio_dev, ADXRS290_READ_REG(ADXRS290_REG_DATAY0), &val);
+
+ return 0;
+}
+
+static const struct iio_trigger_ops adxrs290_trigger_ops = {
+ .set_trigger_state = &adxrs290_data_rdy_trigger_set_state,
+ .validate_device = &iio_trigger_validate_own_device,
+ .try_reenable = &adxrs290_reset_trig,
+};
+
+static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adxrs290_state *st = iio_priv(indio_dev);
+ u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
+ int ret;
+
+ mutex_lock(&st->lock);
+
+ /* exercise a bulk data capture starting from reg DATAX0... */
+ ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
+ sizeof(st->buffer.channels));
+ if (ret < 0)
+ goto done;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
+ pf->timestamp);
+
+done:
+ mutex_unlock(&st->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
#define ADXRS290_ANGL_VEL_CHANNEL(reg, axis) { \
.type = IIO_ANGL_VEL, \
.address = reg, \
@@ -346,6 +509,13 @@ static int adxrs290_read_avail(struct iio_dev *indio_dev,
.info_mask_shared_by_type_available = \
BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | \
BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \
+ .scan_index = ADXRS290_IDX_##axis, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_LE, \
+ }, \
}
static const struct iio_chan_spec adxrs290_channels[] = {
@@ -356,7 +526,20 @@ static const struct iio_chan_spec adxrs290_channels[] = {
.address = ADXRS290_REG_TEMP0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = ADXRS290_IDX_TEMP,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 12,
+ .storagebits = 16,
+ .endianness = IIO_LE,
+ },
},
+ IIO_CHAN_SOFT_TIMESTAMP(ADXRS290_IDX_TS),
+};
+
+static const unsigned long adxrs290_avail_scan_masks[] = {
+ BIT(ADXRS290_IDX_X) | BIT(ADXRS290_IDX_Y) | BIT(ADXRS290_IDX_TEMP),
+ 0
};
static const struct iio_info adxrs290_info = {
@@ -365,6 +548,43 @@ static const struct iio_info adxrs290_info = {
.read_avail = &adxrs290_read_avail,
};
+static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
+{
+ struct adxrs290_state *st = iio_priv(indio_dev);
+ int ret;
+
+ if (!st->spi->irq) {
+ dev_info(&st->spi->dev, "no irq, using polling\n");
+ return 0;
+ }
+
+ st->dready_trig = devm_iio_trigger_alloc(&st->spi->dev, "%s-dev%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (!st->dready_trig)
+ return -ENOMEM;
+
+ st->dready_trig->dev.parent = &st->spi->dev;
+ st->dready_trig->ops = &adxrs290_trigger_ops;
+ iio_trigger_set_drvdata(st->dready_trig, indio_dev);
+
+ ret = devm_request_irq(&st->spi->dev, st->spi->irq,
+ &iio_trigger_generic_data_rdy_poll,
+ IRQF_ONESHOT, "adxrs290_irq", st->dready_trig);
+ if (ret < 0)
+ return dev_err_probe(&st->spi->dev, ret,
+ "request irq %d failed\n", st->spi->irq);
+
+ ret = devm_iio_trigger_register(&st->spi->dev, st->dready_trig);
+ if (ret)
+ return dev_err_probe(&st->spi->dev, ret,
+ "iio trigger register failed\n");
+
+ indio_dev->trig = iio_trigger_get(st->dready_trig);
+
+ return 0;
+}
+
static int adxrs290_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
@@ -384,6 +604,7 @@ static int adxrs290_probe(struct spi_device *spi)
indio_dev->channels = adxrs290_channels;
indio_dev->num_channels = ARRAY_SIZE(adxrs290_channels);
indio_dev->info = &adxrs290_info;
+ indio_dev->available_scan_masks = adxrs290_avail_scan_masks;
mutex_init(&st->lock);
@@ -416,6 +637,11 @@ static int adxrs290_probe(struct spi_device *spi)
/* max transition time to measurement mode */
msleep(ADXRS290_MAX_TRANSITION_TIME_MS);
+ ret = devm_add_action_or_reset(&spi->dev, adxrs290_chip_off_action,
+ indio_dev);
+ if (ret < 0)
+ return ret;
+
ret = adxrs290_get_3db_freq(indio_dev, &val, &val2);
if (ret < 0)
return ret;
@@ -423,6 +649,17 @@ static int adxrs290_probe(struct spi_device *spi)
st->lpf_3db_freq_idx = val;
st->hpf_3db_freq_idx = val2;
+ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+ &iio_pollfunc_store_time,
+ &adxrs290_trigger_handler, NULL);
+ if (ret < 0)
+ return dev_err_probe(&spi->dev, ret,
+ "iio triggered buffer setup failed\n");
+
+ ret = adxrs290_probe_trigger(indio_dev);
+ if (ret < 0)
+ return ret;
+
return devm_iio_device_register(&spi->dev, indio_dev);
}
--
2.20.1