The calculations for temperature and pressure compensation were already slightly optimized in comparison to the data sheet. 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, eliminate an unnecessary parenthesis level and directly return the result of the last equation 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> --- diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c index 75038da..4f6ae4d 100644 --- a/drivers/iio/pressure/bmp280.c +++ b/drivers/iio/pressure/bmp280.c @@ -200,7 +200,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data, struct bmp280_comp_temp *comp, s32 adc_temp) { - s32 var1, var2, t; + s32 var1, var2; var1 = (((adc_temp >> 3) - ((s32) comp->dig_t1 << 1)) * ((s32) comp->dig_t2)) >> 11; @@ -209,9 +209,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data, ((s32) comp->dig_t3)) >> 14; data->t_fine = var1 + var2; - t = (data->t_fine * 5 + 128) >> 8; - - return t; + return (data->t_fine * 5 + 128) >> 8; } /* @@ -229,11 +227,11 @@ static u32 bmp280_compensate_press(struct bmp280_data *data, var1 = ((s64) data->t_fine) - 128000; var2 = var1 * var1 * (s64) comp->dig_p6; - var2 = var2 + ((var1 * (s64) comp->dig_p5) << 17); - var2 = var2 + (((s64) comp->dig_p4) << 35); + var2 += ((var1 * (s64) comp->dig_p5) << 17); + var2 += (((s64) comp->dig_p4) << 35); var1 = ((var1 * var1 * (s64) comp->dig_p3) >> 8) + ((var1 * (s64) comp->dig_p2) << 12); - var1 = (((((s64) 1) << 47) + var1)) * ((s64) comp->dig_p1) >> 33; + var1 = ((((s64) 1) << 47) + var1) * ((s64) comp->dig_p1) >> 33; if (var1 == 0) return 0; @@ -242,9 +240,7 @@ static u32 bmp280_compensate_press(struct bmp280_data *data, p = div64_s64(p, var1); var1 = (((s64) comp->dig_p9) * (p >> 13) * (p >> 13)) >> 25; var2 = (((s64) comp->dig_p8) * p) >> 19; - p = ((p + var1 + var2) >> 8) + (((s64) comp->dig_p7) << 4); - - return (u32) p; + return (u32)((p + var1 + var2) >> 8) + (((s64) comp->dig_p7) << 4); } static int bmp280_read_temp(struct bmp280_data *data, @@ -366,7 +362,7 @@ 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; } @@ -394,7 +390,6 @@ 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; -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html