[PATCH 3/8] iio: mma8452: add freefall / motion interrupt source

From: Martin Kepplinger
Date: Mon Jul 06 2015 - 08:36:26 EST


This adds the freefall / motion interrupt source definitions to the driver.
It is used in this series' next patch, for chips that don't support the
transient interrupt source.

The iio event type is IIO_EV_TYPE_MAG since the threshold for comparison
is no signed value. An interrupt occurs on positive and negative values
when the magnitude crosses the threshold value.

Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christoph Muellner <christoph.muellner@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/iio/accel/mma8452.c | 45 ++++++++++++++++++++++++++++++++++++---------
1 file changed, 36 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 71b40f7..1337707 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -38,9 +38,18 @@
#define MMA8452_DATA_CFG 0x0e
#define MMA8452_HP_FILTER_CUTOFF 0x0f
#define MMA8452_HP_FILTER_CUTOFF_SEL_MASK (BIT(0) | BIT(1))
+#define MMA8452_FF_MT_CFG 0x15
+#define MMA8452_FF_MT_CFG_OAE BIT(6)
+#define MMA8452_FF_MT_CFG_ELE BIT(7)
+#define MMA8452_FF_MT_SRC 0x16
+#define MMA8452_FF_MT_SRC_XHE BIT(1)
+#define MMA8452_FF_MT_SRC_YHE BIT(3)
+#define MMA8452_FF_MT_SRC_ZHE BIT(5)
+#define MMA8452_FF_MT_THS 0x17
+#define MMA8452_FF_MT_THS_MASK 0x7f
+#define MMA8452_FF_MT_COUNT 0x18
#define MMA8452_TRANSIENT_CFG 0x1d
#define MMA8452_TRANSIENT_CFG_ELE BIT(4)
-#define MMA8452_TRANSIENT_CFG_CHAN(chan) BIT(chan + 1)
#define MMA8452_TRANSIENT_CFG_HPF_BYP BIT(0)
#define MMA8452_TRANSIENT_SRC 0x1e
#define MMA8452_TRANSIENT_SRC_XTRANSE BIT(1)
@@ -74,6 +83,7 @@
#define MMA8452_DATA_CFG_HPF_MASK BIT(4)

#define MMA8452_INT_DRDY BIT(0)
+#define MMA8452_INT_FF_MT BIT(2)
#define MMA8452_INT_TRANS BIT(5)

#define MMA8452_DEVICE_ID 0x2a
@@ -591,7 +601,8 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
else
val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);

- val |= MMA8452_TRANSIENT_CFG_ELE;
+ val |= chip->ev_cfg_ele;
+ val |= MMA8452_FF_MT_CFG_OAE;

return mma8452_change_config(data, chip->ev_cfg, val);
}
@@ -632,6 +643,7 @@ static irqreturn_t mma8452_interrupt(int irq, void *p)
{
struct iio_dev *indio_dev = p;
struct mma8452_data *data = iio_priv(indio_dev);
+ const struct mma_chip_info *chip = data->chip_info;
int ret = IRQ_NONE;
int src;

@@ -644,7 +656,10 @@ static irqreturn_t mma8452_interrupt(int irq, void *p)
ret = IRQ_HANDLED;
}

- if (src & MMA8452_INT_TRANS) {
+ if ((src & MMA8452_INT_TRANS &&
+ chip->ev_src == MMA8452_TRANSIENT_SRC) ||
+ (src & MMA8452_INT_FF_MT &&
+ chip->ev_src == MMA8452_FF_MT_SRC)) {
mma8452_transient_interrupt(indio_dev);
ret = IRQ_HANDLED;
}
@@ -705,6 +720,16 @@ static const struct iio_event_spec mma8452_transient_event[] = {
},
};

+static const struct iio_event_spec mma8452_motion_event[] = {
+ {
+ .type = IIO_EV_TYPE_MAG,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+ .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_PERIOD)
+ },
+};
+
/*
* Threshold is configured in fixed 8G/127 steps regardless of
* currently selected scale for measurement.
@@ -988,13 +1013,15 @@ static int mma8452_probe(struct i2c_client *client,

if (client->irq) {
/*
- * Although we enable the transient interrupt source once and
- * for all here the transient event detection itself is not
- * enabled until userspace asks for it by
- * mma8452_write_event_config()
+ * Although we enable the interrupt sources once and for
+ * all here the event detection itself is not enabled until
+ * userspace asks for it by mma8452_write_event_config()
*/
- int supported_interrupts = MMA8452_INT_DRDY | MMA8452_INT_TRANS;
- int enabled_interrupts = MMA8452_INT_TRANS;
+ int supported_interrupts = MMA8452_INT_DRDY |
+ MMA8452_INT_TRANS |
+ MMA8452_INT_FF_MT;
+ int enabled_interrupts = MMA8452_INT_TRANS |
+ MMA8452_INT_FF_MT;

/* Assume wired to INT1 pin */
ret = i2c_smbus_write_byte_data(client,
--
2.1.4

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