The event is triggered when the highpass filtered absolute acceleration
exceeds the threshold.
Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
---
drivers/iio/accel/mma8452.c | 203 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 202 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index c46df4e..3415b36 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -9,7 +9,7 @@
*
* 7-bit I2C slave address 0x1c/0x1d (pin selectable)
*
- * TODO: interrupt, thresholding, orientation / freefall events, autosleep
+ * TODO: orientation / freefall events, autosleep
*/
#include <linux/module.h>
@@ -19,20 +19,33 @@
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/events.h>
#include <linux/delay.h>
#define MMA8452_STATUS 0x00
#define MMA8452_OUT_X 0x01 /* MSB first, 12-bit */
#define MMA8452_OUT_Y 0x03
#define MMA8452_OUT_Z 0x05
+#define MMA8452_INT_SRC 0x0c
#define MMA8452_WHO_AM_I 0x0d
#define MMA8452_DATA_CFG 0x0e
+#define MMA8452_TRANSIENT_CFG 0x1d
+#define MMA8452_TRANSIENT_CFG_ELE BIT(4)
+#define MMA8452_TRANSIENT_CFG_CHAN_MASK(chan) (BIT(1) << chan)
+#define MMA8452_TRANSIENT_SRC 0x1e
+#define MMA8452_TRANSIENT_SRC_XTRANSE BIT(1)
+#define MMA8452_TRANSIENT_SRC_YTRANSE BIT(3)
+#define MMA8452_TRANSIENT_SRC_ZTRANSE BIT(5)
+#define MMA8452_TRANSIENT_THS 0x1f
+#define MMA8452_TRANSIENT_COUNT 0x20
#define MMA8452_OFF_X 0x2f
#define MMA8452_OFF_Y 0x30
#define MMA8452_OFF_Z 0x31
#define MMA8452_CTRL_REG1 0x2a
#define MMA8452_CTRL_REG2 0x2b
#define MMA8452_CTRL_REG2_RST BIT(6)
+#define MMA8452_CTRL_REG4 0x2d
+#define MMA8452_CTRL_REG5 0x2e
#define MMA8452_MAX_REG 0x31
@@ -48,6 +61,13 @@
#define MMA8452_DATA_CFG_FS_4G 1
#define MMA8452_DATA_CFG_FS_8G 2
+#define MMA8452_INT_DRDY BIT(0)
+#define MMA8452_INT_FF_MT BIT(2)
+#define MMA8452_INT_PULSE BIT(3)
+#define MMA8452_INT_LNDPRT BIT(4)
+#define MMA8452_INT_TRANS BIT(5)
+#define MMA8452_INT_ASLP BIT(7)
+
#define MMA8452_DEVICE_ID 0x2a
struct mma8452_data {
@@ -274,6 +294,117 @@ static int mma8452_write_raw(struct iio_dev *indio_dev,
}
}
+static int mma8452_read_thresh(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, enum iio_event_type type,
+ enum iio_event_direction dir, enum iio_event_info info, int *val,
+ int *val2)
+{
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_THS);
+ if (ret < 0)
+ return ret;
+
+ *val = ret & 0x7f;
+
+ return IIO_VAL_INT;
+}
+
+static int mma8452_write_thresh(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, enum iio_event_type type,
+ enum iio_event_direction dir, enum iio_event_info info, int val,
+ int val2)
+{
+ struct mma8452_data *data = iio_priv(indio_dev);
+
+ return mma8452_change_config(data, MMA8452_TRANSIENT_THS, val & 0x7f);
+}
+
+static int mma8452_read_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, enum iio_event_type type,
+ enum iio_event_direction dir)
+{
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
+ if (ret < 0)
+ return ret;
+
+ return ret & MMA8452_TRANSIENT_CFG_CHAN_MASK(chan->scan_index) ? 1 : 0;
+}
+
+static int mma8452_write_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, enum iio_event_type type,
+ enum iio_event_direction dir, int state)
+{
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int val;
+
+ val = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
+ if (val < 0)
+ return val;
+
+ if (state)
+ val |= MMA8452_TRANSIENT_CFG_CHAN_MASK(chan->scan_index);
+ else
+ val &= ~MMA8452_TRANSIENT_CFG_CHAN_MASK(chan->scan_index);
+
+ val |= MMA8452_TRANSIENT_CFG_ELE;
+
+ return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, val);
+}
+
+static void mma8452_push_transient_event(struct iio_dev *indio_dev,
+ int chan, u64 ts)
+{
+ iio_push_event(indio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_ACCEL,
+ chan,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING),
+ ts);
+}
+
+static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
+{
+ struct mma8452_data *data = iio_priv(indio_dev);
+ s64 ts = iio_get_time_ns();
+ int src;
+
+ src = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_SRC);
+ if (src < 0)
+ return;
+
+ if (src & MMA8452_TRANSIENT_SRC_XTRANSE)
+ mma8452_push_transient_event(indio_dev, 0, ts);
+
+ if (src & MMA8452_TRANSIENT_SRC_YTRANSE)
+ mma8452_push_transient_event(indio_dev, 1, ts);
+
+ if (src & MMA8452_TRANSIENT_SRC_ZTRANSE)
+ mma8452_push_transient_event(indio_dev, 2, ts);
+}
+
+static irqreturn_t mma8452_interrupt(int irq, void *p)
+{
+ struct iio_dev *indio_dev = p;
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int src;
+
+ src = i2c_smbus_read_byte_data(data->client, MMA8452_INT_SRC);
+ if (src < 0)
+ return IRQ_NONE;
+
+ if (src & MMA8452_INT_TRANS) {
+ mma8452_transient_interrupt(indio_dev);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
static irqreturn_t mma8452_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
@@ -316,6 +447,31 @@ static int mma8452_reg_access_dbg(struct iio_dev *indio_dev,
return ret;
}
+static const struct iio_event_spec mma8452_transient_event[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+ .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
+ },
+};
+
+/**
+ * Threshold is configured in fixed 8G/127 steps regardless of
+ * currently selected scale for measurement.
+ */
+static IIO_CONST_ATTR_NAMED(accel_transient_scale, in_accel_scale, "0.617742");
+
+static struct attribute *mma8452_event_attributes[] = {
+ &iio_const_attr_accel_transient_scale.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute_group mma8452_event_attribute_group = {
+ .attrs = mma8452_event_attributes,
+ .name = "events",
+};
+
#define MMA8452_CHANNEL(axis, idx) { \
.type = IIO_ACCEL, \
.modified = 1, \
@@ -332,6 +488,8 @@ static int mma8452_reg_access_dbg(struct iio_dev *indio_dev,
.shift = 4, \
.endianness = IIO_BE, \
}, \
+ .event_spec = mma8452_transient_event, \
+ .num_event_specs = ARRAY_SIZE(mma8452_transient_event), \
}
static const struct iio_chan_spec mma8452_channels[] = {
@@ -355,6 +513,11 @@ static const struct iio_info mma8452_info = {
.attrs = &mma8452_group,
.read_raw = &mma8452_read_raw,
.write_raw = &mma8452_write_raw,
+ .event_attrs = &mma8452_event_attribute_group,
+ .read_event_value = &mma8452_read_thresh,
+ .write_event_value = &mma8452_write_thresh,
+ .read_event_config = &mma8452_read_event_config,
+ .write_event_config = &mma8452_write_event_config,
.debugfs_reg_access = &mma8452_reg_access_dbg,
.driver_module = THIS_MODULE,
};
@@ -425,6 +588,31 @@ static int mma8452_probe(struct i2c_client *client,
if (ret < 0)
return ret;
+ /*
+ * By default set transient threshold to max to avoid events if
+ * enabling without configuring threshold
+ */
+ ret = i2c_smbus_write_byte_data(client, MMA8452_TRANSIENT_THS, 0x7f);
+ if (ret < 0)
+ return ret;
+
+ if (client->irq) {
+ int supported_interrupts = MMA8452_INT_TRANS;
+
+ /* Assume wired to INT1 pin */
+ ret = i2c_smbus_write_byte_data(client,
+ MMA8452_CTRL_REG5,
+ supported_interrupts);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte_data(client,
+ MMA8452_CTRL_REG4,
+ supported_interrupts);
+ if (ret < 0)
+ return ret;
+ }
+
data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
(MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
@@ -440,8 +628,21 @@ static int mma8452_probe(struct i2c_client *client,
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
+
+ if (client->irq) {
+ ret = devm_request_threaded_irq(&client->dev,
+ client->irq,
+ NULL, mma8452_interrupt,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ client->name, indio_dev);
+ if (ret)
+ goto device_cleanup;
+ }
return 0;
+device_cleanup:
+ iio_device_unregister(indio_dev);
+
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
--
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