+/* 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;
+}
+