Re: [PATCH v2 2/7] iio: inv_mpu6050: Initial regcache support

[Peter Rosin]

Hi!

On 2016-05-20 04:34, Matt Ranostay wrote:
> On Wed, May 18, 2016 at 8:00 AM, Crestez Dan Leonard
> <leonard.crestez@xxxxxxxxx> wrote:
>> Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
>> ---
>>  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 47 ++++++++++++++++++++++++++++++
>>  drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c  |  5 ----
>>  drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  1 +
>>  drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c  |  5 ----
>>  4 files changed, 48 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> index b269b37..5918c23 100644
>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> @@ -116,6 +116,53 @@ static const struct inv_mpu6050_hw hw_info[] = {
>>         },
>>  };
>>
>> +static bool inv_mpu6050_volatile_reg(struct device *dev, unsigned int reg)
>> +{
>> +       if (reg >= INV_MPU6050_REG_RAW_ACCEL && reg < INV_MPU6050_REG_RAW_ACCEL + 6)
>> +               return true;
>> +       if (reg >= INV_MPU6050_REG_RAW_GYRO && reg < INV_MPU6050_REG_RAW_GYRO + 6)
>> +               return true;
> 
> I think you want to put parenthesis around the addition operations...

Maybe.

> the condition check probably don't evaluate to what you are expecting.

Looks sane to me since + has highest precedence, then < and >=, and && comes
in last...

>> +       switch (reg) {
>> +       case INV_MPU6050_REG_TEMPERATURE:
>> +       case INV_MPU6050_REG_TEMPERATURE + 1:
>> +       case INV_MPU6050_REG_USER_CTRL:
>> +       case INV_MPU6050_REG_PWR_MGMT_1:
>> +       case INV_MPU6050_REG_FIFO_COUNT_H:
>> +       case INV_MPU6050_REG_FIFO_COUNT_H + 1:
>> +       case INV_MPU6050_REG_FIFO_R_W:
>> +               return true;
>> +       default:
>> +               return false;
>> +       }
>> +}

...but even so, I think I would use an ellipsis in the switch statement
instead, like so:

static bool inv_mpu6050_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case INV_MPU6050_REG_RAW_ACCEL ... INV_MPU6050_REG_RAW_ACCEL + 5:
	case INV_MPU6050_REG_RAW_GYRO ... INV_MPU6050_REG_RAW_GYRO  + 5:
	case INV_MPU6050_REG_TEMPERATURE:
	case INV_MPU6050_REG_TEMPERATURE + 1:
	case INV_MPU6050_REG_USER_CTRL:
	case INV_MPU6050_REG_PWR_MGMT_1:
	case INV_MPU6050_REG_FIFO_COUNT_H:
	case INV_MPU6050_REG_FIFO_COUNT_H + 1:
	case INV_MPU6050_REG_FIFO_R_W:
		return true;
	default:
		return false;
	}
}

Cheers,
Peter