On 29/07/14 10:01, Martin Fuzzey wrote:
> The event is triggered when the highpass filtered absolute acceleration
> exceeds the threshold.
>
> Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
I am unsure of the best way to handle this high pass filtered threshold.
Suggestions inline. I'm not happy just throwing it through the
current interface and ignoring the filter...
J
> ---
> 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);
> +}
I'd prefer it if you dropped the wrapper. Makes it more obvious what
is going on below.
Also it should be IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X, IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING).
> +
> +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[] = {
> + {
This is an interesting new event type - or at least it needs some
indication that it is high pass filtered...
It is closer to a rate of change detector than a threshold, but
not quite the same.
We could add an additional IIO_EV_INFO_HIGH_PASS_FILTER_3DB element
to the event to indicate the event is based on high pass filtered data.
Things will get interesting if there is a second low pass filtered
event of otherwise the same type. I guess we'll then just have to have
indexed events (we have hardware that would allow these, but it has never
made much sense to enable it).
> + .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,
This needs documenting under Documentation/ABI/testing/
> + 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
> + */
Why are we enabling it in the probe? Would normally expect events to
only be enabled from userspace once the device is up and running...
> + 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;
We'd normally do this in the other order. Hence have everything up
and running before we expose the userspace interfaces in iio_device_register.
> +
> + 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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