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iio:pressure:bmp280: cleanup 

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@gmx.de>
Reviewed-by: Vlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Hartmut Knaack 2014-12-19 23:59:25 +01:00 committed by Jonathan Cameron
parent 762c4da347
commit 44cf3798a3
1 changed files with 6 additions and 10 deletions
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16
drivers/iio/pressure/bmp280.c
View File

@ -148,7 +148,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
s32 adc_temp) s32 adc_temp)
{ {
int ret; int ret;
s32 var1, var2, t; s32 var1, var2;
__le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2]; __le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START, 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) * ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
((s32)(s16)le16_to_cpu(buf[T3]))) >> 14; ((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
data->t_fine = var1 + var2; return (data->t_fine * 5 + 128) >> 8;
t = (data->t_fine * 5 + 128) >> 8;
return t;
} }
/* /*
@ -203,8 +200,8 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
var1 = ((s64)data->t_fine) - 128000; var1 = ((s64)data->t_fine) - 128000;
var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]); var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
var2 = var2 + ((var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17); var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
var2 = var2 + (((s64)(s16)le16_to_cpu(buf[P4])) << 35); var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) + var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12); ((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33; 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; var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4); 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, 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); BMP280_MODE_NORMAL);
if (ret < 0) { if (ret < 0) {
dev_err(&data->client->dev, dev_err(&data->client->dev,
"failed to write config register\n"); "failed to write ctrl_meas register\n");
return ret; return ret;
} }
@ -358,7 +355,6 @@ static int bmp280_probe(struct i2c_client *client,
if (!indio_dev) if (!indio_dev)
return -ENOMEM; return -ENOMEM;
i2c_set_clientdata(client, indio_dev);
data = iio_priv(indio_dev); data = iio_priv(indio_dev);
mutex_init(&data->lock); mutex_init(&data->lock);
data->client = client; data->client = client;