From 4b04266abe3ea0c5c8f7a82b4d69f0f8e1e81b0a Mon Sep 17 00:00:00 2001 From: Martin Kepplinger Date: Sat, 16 Jan 2016 15:35:20 +0100 Subject: [PATCH] iio: mma8452: add freefall detection for Freescale's accelerometers 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 Signed-off-by: Christoph Muellner Signed-off-by: Jonathan Cameron --- 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 ccc632a7cf01..77b71c2dfd72 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 @@ -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: -- 2.30.2