iio: accel: bma400: Add activity recognition support

Add support for activity recognition like STILL, WALKING, RUNNING
and these events are pushed to the userspace whenever the STEP
interrupt occurs.

Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com>
Link: https://lore.kernel.org/r/20220505133021.22362-8-jagathjog1996@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
index 8483c66..e977326 100644 (file)
--- a/drivers/iio/accel/bma400_core.c
+++ b/drivers/iio/accel/bma400_core.c
@@ -67,6 +67,12 @@ struct bma400_sample_freq {
        int uhz;
 };
 
+enum bma400_activity {
+       BMA400_STILL,
+       BMA400_WALKING,
+       BMA400_RUNNING,
+};
+
 struct bma400_data {
        struct device *dev;
        struct regmap *regmap;
@@ -80,6 +86,7 @@ struct bma400_data {
        struct iio_trigger *trig;
        int steps_enabled;
        bool step_event_en;
+       bool activity_event_en;
        /* Correct time stamp alignment */
        struct {
                __le16 buff[3];
@@ -184,6 +191,12 @@ static const struct iio_event_spec bma400_step_detect_event = {
        .mask_separate = BIT(IIO_EV_INFO_ENABLE),
 };
 
+static const struct iio_event_spec bma400_activity_event = {
+       .type = IIO_EV_TYPE_CHANGE,
+       .dir = IIO_EV_DIR_NONE,
+       .mask_shared_by_type = BIT(IIO_EV_INFO_ENABLE),
+};
+
 #define BMA400_ACC_CHANNEL(_index, _axis) { \
        .type = IIO_ACCEL, \
        .modified = 1, \
@@ -205,6 +218,16 @@ static const struct iio_event_spec bma400_step_detect_event = {
        },                              \
 }
 
+#define BMA400_ACTIVITY_CHANNEL(_chan2) {      \
+       .type = IIO_ACTIVITY,                   \
+       .modified = 1,                          \
+       .channel2 = _chan2,                     \
+       .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),     \
+       .scan_index = -1, /* No buffer support */               \
+       .event_spec = &bma400_activity_event,                   \
+       .num_event_specs = 1,                                   \
+}
+
 static const struct iio_chan_spec bma400_channels[] = {
        BMA400_ACC_CHANNEL(0, X),
        BMA400_ACC_CHANNEL(1, Y),
@@ -229,6 +252,9 @@ static const struct iio_chan_spec bma400_channels[] = {
                .event_spec = &bma400_step_detect_event,
                .num_event_specs = 1,
        },
+       BMA400_ACTIVITY_CHANNEL(IIO_MOD_STILL),
+       BMA400_ACTIVITY_CHANNEL(IIO_MOD_WALKING),
+       BMA400_ACTIVITY_CHANNEL(IIO_MOD_RUNNING),
        IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
@@ -669,6 +695,20 @@ static void bma400_power_disable(void *data_ptr)
                         ERR_PTR(ret));
 }
 
+static enum iio_modifier bma400_act_to_mod(enum bma400_activity activity)
+{
+       switch (activity) {
+       case BMA400_STILL:
+               return IIO_MOD_STILL;
+       case BMA400_WALKING:
+               return IIO_MOD_WALKING;
+       case BMA400_RUNNING:
+               return IIO_MOD_RUNNING;
+       default:
+               return IIO_NO_MOD;
+       }
+}
+
 static int bma400_init(struct bma400_data *data)
 {
        unsigned int val;
@@ -766,6 +806,7 @@ static int bma400_read_raw(struct iio_dev *indio_dev,
                           int *val2, long mask)
 {
        struct bma400_data *data = iio_priv(indio_dev);
+       unsigned int activity;
        int ret;
 
        switch (mask) {
@@ -778,6 +819,21 @@ static int bma400_read_raw(struct iio_dev *indio_dev,
                        return ret;
                case IIO_STEPS:
                        return bma400_get_steps_reg(data, val);
+               case IIO_ACTIVITY:
+                       ret = regmap_read(data->regmap, BMA400_STEP_STAT_REG,
+                                         &activity);
+                       if (ret)
+                               return ret;
+                       /*
+                        * The device does not support confidence value levels,
+                        * so we will always have 100% for current activity and
+                        * 0% for the others.
+                        */
+                       if (chan->channel2 == bma400_act_to_mod(activity))
+                               *val = 100;
+                       else
+                               *val = 0;
+                       return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
@@ -927,6 +983,8 @@ static int bma400_read_event_config(struct iio_dev *indio_dev,
        switch (chan->type) {
        case IIO_STEPS:
                return data->step_event_en;
+       case IIO_ACTIVITY:
+               return data->activity_event_en;
        default:
                return -EINVAL;
        }
@@ -964,6 +1022,18 @@ static int bma400_write_event_config(struct iio_dev *indio_dev,
                ret = bma400_steps_event_enable(data, state);
                mutex_unlock(&data->mutex);
                return ret;
+       case IIO_ACTIVITY:
+               mutex_lock(&data->mutex);
+               if (!data->step_event_en) {
+                       ret = bma400_steps_event_enable(data, true);
+                       if (ret) {
+                               mutex_unlock(&data->mutex);
+                               return ret;
+                       }
+               }
+               data->activity_event_en = state;
+               mutex_unlock(&data->mutex);
+               return 0;
        default:
                return -EINVAL;
        }
@@ -1049,6 +1119,7 @@ static irqreturn_t bma400_interrupt(int irq, void *private)
        struct iio_dev *indio_dev = private;
        struct bma400_data *data = iio_priv(indio_dev);
        s64 timestamp = iio_get_time_ns(indio_dev);
+       unsigned int act;
        int ret;
 
        /* Lock to protect the data->status */
@@ -1069,6 +1140,20 @@ static irqreturn_t bma400_interrupt(int irq, void *private)
                                                  IIO_EV_TYPE_CHANGE,
                                                  IIO_EV_DIR_NONE),
                               timestamp);
+
+               if (data->activity_event_en) {
+                       ret = regmap_read(data->regmap, BMA400_STEP_STAT_REG,
+                                         &act);
+                       if (ret)
+                               goto unlock_err;
+
+                       iio_push_event(indio_dev,
+                                      IIO_MOD_EVENT_CODE(IIO_ACTIVITY, 0,
+                                                         bma400_act_to_mod(act),
+                                                         IIO_EV_TYPE_CHANGE,
+                                                         IIO_EV_DIR_NONE),
+                                      timestamp);
+               }
        }
 
        if (FIELD_GET(BMA400_INT_DRDY_MSK, le16_to_cpu(data->status))) {