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

[Crestez Dan Leonard]

On 05/20/2016 09:39 AM, Peter Rosin wrote:
> 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...
> 
> ...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;
> 	}
> }

Neat, I didn't know about this extension. It does look nicer in this
function.