diff options
Diffstat (limited to 'drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c')
| -rw-r--r-- | drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c | 69 |
1 files changed, 33 insertions, 36 deletions
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c index 7327e5723f96..970cf5c47f68 100644 --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_aux.c @@ -14,6 +14,8 @@ /* * i2c master auxiliary bus transfer function. * Requires the i2c operations to be correctly setup before. + * Disables SLV0 and checks for NACK status internally. + * Assumes that only SLV0 is used for transfers. */ static int inv_mpu_i2c_master_xfer(const struct inv_mpu6050_state *st) { @@ -23,6 +25,7 @@ static int inv_mpu_i2c_master_xfer(const struct inv_mpu6050_state *st) uint8_t d; unsigned int user_ctrl; int ret; + unsigned int status; /* set sample rate */ d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(freq); @@ -51,12 +54,27 @@ static int inv_mpu_i2c_master_xfer(const struct inv_mpu6050_state *st) if (ret) goto error_restore_rate; + /* disable i2c slave */ + ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); + if (ret) + goto error_disable_i2c; + + /* check i2c status */ + ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status); + if (ret) + return ret; + + if (status & INV_MPU6050_BIT_I2C_SLV0_NACK) + return -EIO; + return 0; error_stop_i2c: regmap_write(st->map, st->reg->user_ctrl, st->chip_config.user_ctrl); error_restore_rate: regmap_write(st->map, st->reg->sample_rate_div, st->chip_config.divider); +error_disable_i2c: + regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); return ret; } @@ -71,6 +89,19 @@ int inv_mpu_aux_init(const struct inv_mpu6050_state *st) unsigned int val; int ret; + /* + * Code based on the vendor Linux kernel v3.0, + * the exact meaning is unknown. + */ + if (st->chip_type == INV_MPU9150) { + unsigned int mask = BIT(7); + + val = st->level_shifter ? mask : 0; + ret = regmap_update_bits(st->map, 0x1, mask, val); + if (ret) + return ret; + } + /* configure i2c master */ val = INV_MPU6050_BITS_I2C_MST_CLK_400KHZ | INV_MPU6050_BIT_WAIT_FOR_ES; @@ -104,7 +135,6 @@ int inv_mpu_aux_init(const struct inv_mpu6050_state *st) int inv_mpu_aux_read(const struct inv_mpu6050_state *st, uint8_t addr, uint8_t reg, uint8_t *val, size_t size) { - unsigned int status; int ret; if (size > 0x0F) @@ -123,30 +153,14 @@ int inv_mpu_aux_read(const struct inv_mpu6050_state *st, uint8_t addr, if (ret) return ret; - /* do i2c xfer */ + /* do i2c xfer, disable i2c slave and check status*/ ret = inv_mpu_i2c_master_xfer(st); if (ret) - goto error_disable_i2c; - - /* disable i2c slave */ - ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); - if (ret) - goto error_disable_i2c; - - /* check i2c status */ - ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status); - if (ret) return ret; - if (status & INV_MPU6050_BIT_I2C_SLV0_NACK) - return -EIO; /* read data in registers */ return regmap_bulk_read(st->map, INV_MPU6050_REG_EXT_SENS_DATA, val, size); - -error_disable_i2c: - regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); - return ret; } /** @@ -161,7 +175,6 @@ error_disable_i2c: int inv_mpu_aux_write(const struct inv_mpu6050_state *st, uint8_t addr, uint8_t reg, uint8_t val) { - unsigned int status; int ret; /* setup i2c SLV0 control: i2c addr, register, value, enable + size */ @@ -179,26 +192,10 @@ int inv_mpu_aux_write(const struct inv_mpu6050_state *st, uint8_t addr, if (ret) return ret; - /* do i2c xfer */ + /* do i2c xfer, disable i2c slave and check status*/ ret = inv_mpu_i2c_master_xfer(st); if (ret) - goto error_disable_i2c; - - /* disable i2c slave */ - ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); - if (ret) - goto error_disable_i2c; - - /* check i2c status */ - ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status); - if (ret) return ret; - if (status & INV_MPU6050_BIT_I2C_SLV0_NACK) - return -EIO; return 0; - -error_disable_i2c: - regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0); - return ret; } |