iio: pressure: bmp280: Generalize read_*() functions

Add the coefficients for the IIO standard units and the IIO value
inside the chip_info structure.

Move the calculations for the IIO unit compatibility from inside the
read_{temp,press,humid}() functions and move them to the general
read_raw() function.

In this way, all the data for the calculation of the value are
located in the chip_info structure of the respective sensor.
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Acked-by: Adam Rizkalla <ajarizzo@gmail.com>
Link: https://patch.msgid.link/20240628171726.124852-2-vassilisamir@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/pressure/bmp280.h

@@ -446,10 +446,17 @@ struct bmp280_chip_info {
 	int num_sampling_freq_avail;
 	int sampling_freq_default;
 
+	const int *temp_coeffs;
+	const int temp_coeffs_type;
+	const int *press_coeffs;
+	const int press_coeffs_type;
+	const int *humid_coeffs;
+	const int humid_coeffs_type;
+
 	int (*chip_config)(struct bmp280_data *data);
-	int (*read_temp)(struct bmp280_data *data, int *val, int *val2);
-	int (*read_press)(struct bmp280_data *data, int *val, int *val2);
-	int (*read_humid)(struct bmp280_data *data, int *val, int *val2);
+	int (*read_temp)(struct bmp280_data *data, s32 *adc_temp);
+	int (*read_press)(struct bmp280_data *data, u32 *adc_press);
+	int (*read_humid)(struct bmp280_data *data, u32 *adc_humidity);
 	int (*read_calib)(struct bmp280_data *data);
 	int (*preinit)(struct bmp280_data *data);
 };