On 16/01/16 14:35, Martin Kepplinger wrote:
> This adds freefall event detection to the supported devices. It adds
> the in_accel_x&y&z_mag_falling_en iio event attribute, which activates
> freefall mode.
> 
> In freefall mode, the current acceleration magnitude (AND combination
> of all axis values) is compared to the specified threshold.
> If it falls under the threshold (in_accel_mag_falling_value),
> the appropriate IIO event code is generated.
> 
> This is what the sysfs "events" directory for these devices looks
> like after this change:
> 
> -rw-r--r--    4096 Oct 23 08:45 in_accel_mag_falling_period
> -rw-r--r--    4096 Oct 23 08:45 in_accel_mag_falling_value
> -rw-r--r--    4096 Oct 23 08:45 in_accel_mag_rising_period
> -rw-r--r--    4096 Oct 23 08:45 in_accel_mag_rising_value
> -r--r--r--    4096 Oct 23 08:45 in_accel_scale
> -rw-r--r--    4096 Oct 23 08:45 in_accel_x&y&z_mag_falling_en
> -rw-r--r--    4096 Oct 23 08:45 in_accel_x_mag_rising_en
> -rw-r--r--    4096 Oct 23 08:45 in_accel_y_mag_rising_en
> -rw-r--r--    4096 Oct 23 08:45 in_accel_z_mag_rising_en
> 
> Signed-off-by: Martin Kepplinger <[email protected]>
> Signed-off-by: Christoph Muellner <[email protected]>
Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan
> ---
> revision history
> ----------------
> v1:
>         initial post
> v2:
>         build all from correct event and channel spec structs
> v3:
>         rising and falling are treated as equal now. Until last time, I had
>         misunderstood the iio events' user API definition. This works and
>         values always reflect the current state of operation.
> v4:
>       fix error that caused a build warning
> v5:
>       changes according to Peter's review
> v6:
>       changes according to Jonathan's review:
>       improve set_freefall_mode(); fix error case
> 
> 
>  drivers/iio/accel/mma8452.c | 160 
> +++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 144 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index ccc632a..77b71c2 100644
> --- a/drivers/iio/accel/mma8452.c
> +++ b/drivers/iio/accel/mma8452.c
> @@ -15,7 +15,7 @@
>   *
>   * 7-bit I2C slave address 0x1c/0x1d (pin selectable)
>   *
> - * TODO: orientation / freefall events, autosleep
> + * TODO: orientation events, autosleep
>   */
>  
>  #include <linux/module.h>
> @@ -416,6 +416,51 @@ fail:
>       return ret;
>  }
>  
> +/* returns >0 if in freefall mode, 0 if not or <0 if an error occured */
> +static int mma8452_freefall_mode_enabled(struct mma8452_data *data)
> +{
> +     int val;
> +     const struct mma_chip_info *chip = data->chip_info;
> +
> +     val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
> +     if (val < 0)
> +             return val;
> +
> +     return !(val & MMA8452_FF_MT_CFG_OAE);
> +}
> +
> +static int mma8452_set_freefall_mode(struct mma8452_data *data, bool state)
> +{
> +     int val;
> +     const struct mma_chip_info *chip = data->chip_info;
> +
> +     if ((state && mma8452_freefall_mode_enabled(data)) ||
> +         (!state && !(mma8452_freefall_mode_enabled(data))))
> +             return 0;
> +
> +     val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
> +     if (val < 0)
> +             return val;
> +
> +     if (state) {
> +             val |= BIT(idx_x + chip->ev_cfg_chan_shift);
> +             val |= BIT(idx_y + chip->ev_cfg_chan_shift);
> +             val |= BIT(idx_z + chip->ev_cfg_chan_shift);
> +             val &= ~MMA8452_FF_MT_CFG_OAE;
> +     } else {
> +             val &= ~BIT(idx_x + chip->ev_cfg_chan_shift);
> +             val &= ~BIT(idx_y + chip->ev_cfg_chan_shift);
> +             val &= ~BIT(idx_z + chip->ev_cfg_chan_shift);
> +             val |= MMA8452_FF_MT_CFG_OAE;
> +     }
> +
> +     val = mma8452_change_config(data, chip->ev_cfg, val);
> +     if (val)
> +             return val;
> +
> +     return 0;
> +}
> +
>  static int mma8452_set_hp_filter_frequency(struct mma8452_data *data,
>                                          int val, int val2)
>  {
> @@ -609,12 +654,22 @@ static int mma8452_read_event_config(struct iio_dev 
> *indio_dev,
>       const struct mma_chip_info *chip = data->chip_info;
>       int ret;
>  
> -     ret = i2c_smbus_read_byte_data(data->client,
> -                                    data->chip_info->ev_cfg);
> -     if (ret < 0)
> -             return ret;
> +     switch (dir) {
> +     case IIO_EV_DIR_FALLING:
> +             return mma8452_freefall_mode_enabled(data);
> +     case IIO_EV_DIR_RISING:
> +             if (mma8452_freefall_mode_enabled(data))
> +                     return 0;
> +
> +             ret = i2c_smbus_read_byte_data(data->client,
> +                                            data->chip_info->ev_cfg);
> +             if (ret < 0)
> +                     return ret;
>  
> -     return !!(ret & BIT(chan->scan_index + chip->ev_cfg_chan_shift));
> +             return !!(ret & BIT(chan->scan_index + 
> chip->ev_cfg_chan_shift));
> +     default:
> +             return -EINVAL;
> +     }
>  }
>  
>  static int mma8452_write_event_config(struct iio_dev *indio_dev,
> @@ -627,19 +682,35 @@ static int mma8452_write_event_config(struct iio_dev 
> *indio_dev,
>       const struct mma_chip_info *chip = data->chip_info;
>       int val;
>  
> -     val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
> -     if (val < 0)
> -             return val;
> +     switch (dir) {
> +     case IIO_EV_DIR_FALLING:
> +             return mma8452_set_freefall_mode(data, state);
> +     case IIO_EV_DIR_RISING:
> +             val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
> +             if (val < 0)
> +                     return val;
> +
> +             if (state) {
> +                     if (mma8452_freefall_mode_enabled(data)) {
> +                             val &= ~BIT(idx_x + chip->ev_cfg_chan_shift);
> +                             val &= ~BIT(idx_y + chip->ev_cfg_chan_shift);
> +                             val &= ~BIT(idx_z + chip->ev_cfg_chan_shift);
> +                             val |= MMA8452_FF_MT_CFG_OAE;
> +                     }
> +                     val |= BIT(chan->scan_index + chip->ev_cfg_chan_shift);
> +             } else {
> +                     if (mma8452_freefall_mode_enabled(data))
> +                             return 0;
>  
> -     if (state)
> -             val |= BIT(chan->scan_index + chip->ev_cfg_chan_shift);
> -     else
> -             val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);
> +                     val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);
> +             }
>  
> -     val |= chip->ev_cfg_ele;
> -     val |= MMA8452_FF_MT_CFG_OAE;
> +             val |= chip->ev_cfg_ele;
>  
> -     return mma8452_change_config(data, chip->ev_cfg, val);
> +             return mma8452_change_config(data, chip->ev_cfg, val);
> +     default:
> +             return -EINVAL;
> +     }
>  }
>  
>  static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
> @@ -652,6 +723,16 @@ static void mma8452_transient_interrupt(struct iio_dev 
> *indio_dev)
>       if (src < 0)
>               return;
>  
> +     if (mma8452_freefall_mode_enabled(data)) {
> +             iio_push_event(indio_dev,
> +                            IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
> +                                               IIO_MOD_X_AND_Y_AND_Z,
> +                                               IIO_EV_TYPE_MAG,
> +                                               IIO_EV_DIR_FALLING),
> +                            ts);
> +             return;
> +     }
> +
>       if (src & data->chip_info->ev_src_xe)
>               iio_push_event(indio_dev,
>                              IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X,
> @@ -745,6 +826,27 @@ static int mma8452_reg_access_dbg(struct iio_dev 
> *indio_dev,
>       return 0;
>  }
>  
> +static const struct iio_event_spec mma8452_freefall_event[] = {
> +     {
> +             .type = IIO_EV_TYPE_MAG,
> +             .dir = IIO_EV_DIR_FALLING,
> +             .mask_separate = BIT(IIO_EV_INFO_ENABLE),
> +             .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
> +                                     BIT(IIO_EV_INFO_PERIOD) |
> +                                     BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB)
> +     },
> +};
> +
> +static const struct iio_event_spec mma8652_freefall_event[] = {
> +     {
> +             .type = IIO_EV_TYPE_MAG,
> +             .dir = IIO_EV_DIR_FALLING,
> +             .mask_separate = BIT(IIO_EV_INFO_ENABLE),
> +             .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
> +                                     BIT(IIO_EV_INFO_PERIOD)
> +     },
> +};
> +
>  static const struct iio_event_spec mma8452_transient_event[] = {
>       {
>               .type = IIO_EV_TYPE_MAG,
> @@ -781,6 +883,24 @@ static struct attribute_group 
> mma8452_event_attribute_group = {
>       .attrs = mma8452_event_attributes,
>  };
>  
> +#define MMA8452_FREEFALL_CHANNEL(modifier) { \
> +     .type = IIO_ACCEL, \
> +     .modified = 1, \
> +     .channel2 = modifier, \
> +     .scan_index = -1, \
> +     .event_spec = mma8452_freefall_event, \
> +     .num_event_specs = ARRAY_SIZE(mma8452_freefall_event), \
> +}
> +
> +#define MMA8652_FREEFALL_CHANNEL(modifier) { \
> +     .type = IIO_ACCEL, \
> +     .modified = 1, \
> +     .channel2 = modifier, \
> +     .scan_index = -1, \
> +     .event_spec = mma8652_freefall_event, \
> +     .num_event_specs = ARRAY_SIZE(mma8652_freefall_event), \
> +}
> +
>  #define MMA8452_CHANNEL(axis, idx, bits) { \
>       .type = IIO_ACCEL, \
>       .modified = 1, \
> @@ -827,6 +947,7 @@ static const struct iio_chan_spec mma8452_channels[] = {
>       MMA8452_CHANNEL(Y, idx_y, 12),
>       MMA8452_CHANNEL(Z, idx_z, 12),
>       IIO_CHAN_SOFT_TIMESTAMP(idx_ts),
> +     MMA8452_FREEFALL_CHANNEL(IIO_MOD_X_AND_Y_AND_Z),
>  };
>  
>  static const struct iio_chan_spec mma8453_channels[] = {
> @@ -834,6 +955,7 @@ static const struct iio_chan_spec mma8453_channels[] = {
>       MMA8452_CHANNEL(Y, idx_y, 10),
>       MMA8452_CHANNEL(Z, idx_z, 10),
>       IIO_CHAN_SOFT_TIMESTAMP(idx_ts),
> +     MMA8452_FREEFALL_CHANNEL(IIO_MOD_X_AND_Y_AND_Z),
>  };
>  
>  static const struct iio_chan_spec mma8652_channels[] = {
> @@ -841,6 +963,7 @@ static const struct iio_chan_spec mma8652_channels[] = {
>       MMA8652_CHANNEL(Y, idx_y, 12),
>       MMA8652_CHANNEL(Z, idx_z, 12),
>       IIO_CHAN_SOFT_TIMESTAMP(idx_ts),
> +     MMA8652_FREEFALL_CHANNEL(IIO_MOD_X_AND_Y_AND_Z),
>  };
>  
>  static const struct iio_chan_spec mma8653_channels[] = {
> @@ -848,6 +971,7 @@ static const struct iio_chan_spec mma8653_channels[] = {
>       MMA8652_CHANNEL(Y, idx_y, 10),
>       MMA8652_CHANNEL(Z, idx_z, 10),
>       IIO_CHAN_SOFT_TIMESTAMP(idx_ts),
> +     MMA8652_FREEFALL_CHANNEL(IIO_MOD_X_AND_Y_AND_Z),
>  };
>  
>  enum {
> @@ -1190,6 +1314,10 @@ static int mma8452_probe(struct i2c_client *client,
>       if (ret < 0)
>               goto buffer_cleanup;
>  
> +     ret = mma8452_set_freefall_mode(data, false);
> +     if (ret)
> +             return ret;
> +
>       return 0;
>  
>  buffer_cleanup:
> 

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