diff options
Diffstat (limited to 'drivers/iio/accel/mma8452.c')
| -rw-r--r-- | drivers/iio/accel/mma8452.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c index 17d72bc2e6fa..9c4a84a72ad4 100644 --- a/drivers/iio/accel/mma8452.c +++ b/drivers/iio/accel/mma8452.c @@ -393,24 +393,47 @@ static int mma8452_active(struct mma8452_data *data) data->ctrl_reg1); } +/* returns >0 if active, 0 if in standby and <0 on error */ +static int mma8452_is_active(struct mma8452_data *data) +{ + int reg; + + reg = i2c_smbus_read_byte_data(data->client, MMA8452_CTRL_REG1); + if (reg < 0) + return reg; + + return reg & MMA8452_CTRL_ACTIVE; +} + static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val) { int ret; + int is_active; mutex_lock(&data->lock); - /* config can only be changed when in standby */ - ret = mma8452_standby(data); - if (ret < 0) + is_active = mma8452_is_active(data); + if (is_active < 0) { + ret = is_active; goto fail; + } + + /* config can only be changed when in standby */ + if (is_active > 0) { + ret = mma8452_standby(data); + if (ret < 0) + goto fail; + } ret = i2c_smbus_write_byte_data(data->client, reg, val); if (ret < 0) goto fail; - ret = mma8452_active(data); - if (ret < 0) - goto fail; + if (is_active > 0) { + ret = mma8452_active(data); + if (ret < 0) + goto fail; + } ret = 0; fail: |