On 22/12/14 12:29, Vlad Dogaru wrote:
> On Fri, Dec 19, 2014 at 11:59:25PM +0100, Hartmut Knaack wrote:
>> The calculations for temperature and pressure compensation were already slightly
>> optimized in comparison to the datasheet. So, it makes sense to optimize even a
>> bit more, making proper use of C operators:
>> - variable t in bmp280_compensate_temp() can be eliminated by directly
>> returning the result of the relevant equation.
>> - make use of the += operator and eliminate an unnecessary parenthesis level in
>> bmp280_compensate_press().
>> When the initialization of the ctrl_meas register fails, the error message will
>> now mention the right register name.
>> During probe, i2c_set_clientdata() is called, although it is not necessary. Drop
>> it.
>>
>> Signed-off-by: Hartmut Knaack <knaack.h@xxxxxx>
> Reviewed-by: Vlad Dogaru <vlad.dogaru@xxxxxxxxx>
>
> Thanks for following up with this one, Hartmut.
Applied to the togreg branch of iio.git -- initially pushed out as testing
for the autobuilders to play with it. Well, it will be once I've caught up
with some more reviews..
Jonathan
>
>> ---
>> Changes in V2:
>> Rebase after refactoring of compensation code.
>>
>> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
>> index 47dfd34..7c623e2 100644
>> --- a/drivers/iio/pressure/bmp280.c
>> +++ b/drivers/iio/pressure/bmp280.c
>> @@ -148,7 +148,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
>> s32 adc_temp)
>> {
>> int ret;
>> - s32 var1, var2, t;
>> + s32 var1, var2;
>> __le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
>>
>> ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
>> @@ -173,10 +173,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
>> ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
>> ((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
>>
>> - data->t_fine = var1 + var2;
>> - t = (data->t_fine * 5 + 128) >> 8;
>> -
>> - return t;
>> + return (data->t_fine * 5 + 128) >> 8;
>> }
>>
>> /*
>> @@ -203,8 +200,8 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
>>
>> var1 = ((s64)data->t_fine) - 128000;
>> var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
>> - var2 = var2 + ((var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17);
>> - var2 = var2 + (((s64)(s16)le16_to_cpu(buf[P4])) << 35);
>> + var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
>> + var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
>> var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
>> ((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
>> var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;
>> @@ -218,7 +215,7 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
>> var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
>> p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);
>>
>> - return (u32) p;
>> + return (u32)p;
>> }
>>
>> static int bmp280_read_temp(struct bmp280_data *data,
>> @@ -330,7 +327,7 @@ static int bmp280_chip_init(struct bmp280_data *data)
>> BMP280_MODE_NORMAL);
>> if (ret < 0) {
>> dev_err(&data->client->dev,
>> - "failed to write config register\n");
>> + "failed to write ctrl_meas register\n");
>> return ret;
>> }
>>
>> @@ -358,7 +355,6 @@ static int bmp280_probe(struct i2c_client *client,
>> if (!indio_dev)
>> return -ENOMEM;
>>
>> - i2c_set_clientdata(client, indio_dev);
>> data = iio_priv(indio_dev);
>> mutex_init(&data->lock);
>> data->client = client;
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