iio: pressure: bmp280: simplify driver initialization logic

Simplified common initialization logic of different sensor types
unifying calibration and initial configuration recovery.

Default config param values of each sensor type are stored inside
chip_info structure and used to initialize sensor data struct instance.

The helper functions for read each sensor type calibration are converted
to a callback available on the chip_info struct.

Separated bme280 specific calibration code from bmp280 function. Dropped
the additional chip_id argument in bmp280 code as is not longer required.
Now both bmp280/bme280 calibration function use same signature as bmp180.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Link: https://lore.kernel.org/r/584c90f309e4f24bf2e4aa2b15c8577d288f978d.1663025017.git.ang.iglesiasg@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index c86dae3..067e56b 100644 (file)
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -115,19 +115,28 @@ struct bmp280_data {
 };
 
 struct bmp280_chip_info {
+       unsigned int id_reg;
+
+       int num_channels;
+       unsigned int start_up_time;
+
        const int *oversampling_temp_avail;
        int num_oversampling_temp_avail;
+       int oversampling_temp_default;
 
        const int *oversampling_press_avail;
        int num_oversampling_press_avail;
+       int oversampling_press_default;
 
        const int *oversampling_humid_avail;
        int num_oversampling_humid_avail;
+       int oversampling_humid_default;
 
        int (*chip_config)(struct bmp280_data *);
        int (*read_temp)(struct bmp280_data *, int *);
        int (*read_press)(struct bmp280_data *, int *, int *);
        int (*read_humid)(struct bmp280_data *, int *, int *);
+       int (*read_calib)(struct bmp280_data *);
 };
 
 /*
@@ -154,15 +163,10 @@ static const struct iio_chan_spec bmp280_channels[] = {
        },
 };
 
-static int bmp280_read_calib(struct bmp280_data *data,
-                            struct bmp280_calib *calib,
-                            unsigned int chip)
+static int bmp280_read_calib(struct bmp280_data *data)
 {
+       struct bmp280_calib *calib = &data->calib.bmp280;
        __le16 c_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
-       struct device *dev = data->dev;
-       unsigned int tmp;
-       __le16 l16;
-       __be16 b16;
        int ret;
 
 
@@ -194,6 +198,25 @@ static int bmp280_read_calib(struct bmp280_data *data,
        calib->P8 = le16_to_cpu(c_buf[P8]);
        calib->P9 = le16_to_cpu(c_buf[P9]);
 
+       return 0;
+}
+
+static int bme280_read_calib(struct bmp280_data *data)
+{
+       struct bmp280_calib *calib = &data->calib.bmp280;
+       struct device *dev = data->dev;
+       unsigned int tmp;
+       __le16 l16;
+       __be16 b16;
+       int ret;
+
+       /* Load shared calibration params with bmp280 first */
+       ret = bmp280_read_calib(data);
+       if  (ret < 0) {
+               dev_err(dev, "failed to read common bmp280 calibration parameters\n");
+               return ret;
+       }
+
        /*
         * Read humidity calibration values.
         * Due to some odd register addressing we cannot just
@@ -201,8 +224,6 @@ static int bmp280_read_calib(struct bmp280_data *data,
         * value separately and sometimes do some bit shifting...
         * Humidity data is only available on BME280.
         */
-       if (chip != BME280_CHIP_ID)
-               return 0;
 
        ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &tmp);
        if (ret < 0) {
@@ -637,15 +658,32 @@ static int bmp280_chip_config(struct bmp280_data *data)
 static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
 
 static const struct bmp280_chip_info bmp280_chip_info = {
+       .id_reg = BMP280_REG_ID,
+       .start_up_time = 2000,
+       .num_channels = 2,
+
        .oversampling_temp_avail = bmp280_oversampling_avail,
        .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+       /*
+        * Oversampling config values on BMx280 have one additional setting
+        * that other generations of the family don't:
+        * The value 0 means the measurement is bypassed instead of
+        * oversampling set to x1.
+        *
+        * To account for this difference, and preserve the same common
+        * config logic, this is handled later on chip_config callback
+        * incrementing one unit the oversampling setting.
+        */
+       .oversampling_temp_default = BMP280_OSRS_TEMP_2X - 1,
 
        .oversampling_press_avail = bmp280_oversampling_avail,
        .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+       .oversampling_press_default = BMP280_OSRS_PRESS_16X - 1,
 
        .chip_config = bmp280_chip_config,
        .read_temp = bmp280_read_temp,
        .read_press = bmp280_read_press,
+       .read_calib = bmp280_read_calib,
 };
 
 static int bme280_chip_config(struct bmp280_data *data)
@@ -667,19 +705,27 @@ static int bme280_chip_config(struct bmp280_data *data)
 }
 
 static const struct bmp280_chip_info bme280_chip_info = {
+       .id_reg = BMP280_REG_ID,
+       .start_up_time = 2000,
+       .num_channels = 3,
+
        .oversampling_temp_avail = bmp280_oversampling_avail,
        .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+       .oversampling_temp_default = BMP280_OSRS_TEMP_2X - 1,
 
        .oversampling_press_avail = bmp280_oversampling_avail,
        .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+       .oversampling_press_default = BMP280_OSRS_PRESS_16X - 1,
 
        .oversampling_humid_avail = bmp280_oversampling_avail,
        .num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+       .oversampling_humid_default = BMP280_OSRS_HUMIDITY_16X - 1,
 
        .chip_config = bme280_chip_config,
        .read_temp = bmp280_read_temp,
        .read_press = bmp280_read_press,
        .read_humid = bmp280_read_humid,
+       .read_calib = bme280_read_calib,
 };
 
 static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
@@ -747,9 +793,9 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
        return 0;
 }
 
-static int bmp180_read_calib(struct bmp280_data *data,
-                            struct bmp180_calib *calib)
+static int bmp180_read_calib(struct bmp280_data *data)
 {
+       struct bmp180_calib *calib = &data->calib.bmp180;
        __be16 buf[BMP180_REG_CALIB_COUNT / 2];
        int ret;
        int i;
@@ -915,17 +961,24 @@ static const int bmp180_oversampling_temp_avail[] = { 1 };
 static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
 
 static const struct bmp280_chip_info bmp180_chip_info = {
+       .id_reg = BMP280_REG_ID,
+       .start_up_time = 2000,
+       .num_channels = 2,
+
        .oversampling_temp_avail = bmp180_oversampling_temp_avail,
        .num_oversampling_temp_avail =
                ARRAY_SIZE(bmp180_oversampling_temp_avail),
+       .oversampling_temp_default = 0,
 
        .oversampling_press_avail = bmp180_oversampling_press_avail,
        .num_oversampling_press_avail =
                ARRAY_SIZE(bmp180_oversampling_press_avail),
+       .oversampling_press_default = BMP180_MEAS_PRESS_8X,
 
        .chip_config = bmp180_chip_config,
        .read_temp = bmp180_read_temp,
        .read_press = bmp180_read_press,
+       .read_calib = bmp180_read_calib,
 };
 
 static irqreturn_t bmp085_eoc_irq(int irq, void *d)
@@ -992,6 +1045,7 @@ int bmp280_common_probe(struct device *dev,
                        const char *name,
                        int irq)
 {
+       const struct bmp280_chip_info *chip_info;
        struct iio_dev *indio_dev;
        struct bmp280_data *data;
        struct gpio_desc *gpiod;
@@ -1013,30 +1067,25 @@ int bmp280_common_probe(struct device *dev,
 
        switch (chip) {
        case BMP180_CHIP_ID:
-               indio_dev->num_channels = 2;
-               data->chip_info = &bmp180_chip_info;
-               data->oversampling_press = ilog2(8);
-               data->oversampling_temp = ilog2(1);
-               data->start_up_time = 10000;
+               chip_info = &bmp180_chip_info;
                break;
        case BMP280_CHIP_ID:
-               indio_dev->num_channels = 2;
-               data->chip_info = &bmp280_chip_info;
-               data->oversampling_press = ilog2(16);
-               data->oversampling_temp = ilog2(2);
-               data->start_up_time = 2000;
+               chip_info = &bmp280_chip_info;
                break;
        case BME280_CHIP_ID:
-               indio_dev->num_channels = 3;
-               data->chip_info = &bme280_chip_info;
-               data->oversampling_press = ilog2(16);
-               data->oversampling_humid = ilog2(16);
-               data->oversampling_temp = ilog2(2);
-               data->start_up_time = 2000;
+               chip_info = &bme280_chip_info;
                break;
        default:
                return -EINVAL;
        }
+       data->chip_info = chip_info;
+
+       /* Apply initial values from chip info structure */
+       indio_dev->num_channels = chip_info->num_channels;
+       data->oversampling_press = chip_info->oversampling_press_default;
+       data->oversampling_humid = chip_info->oversampling_humid_default;
+       data->oversampling_temp = chip_info->oversampling_temp_default;
+       data->start_up_time = chip_info->start_up_time;
 
        /* Bring up regulators */
        regulator_bulk_set_supply_names(data->supplies,
@@ -1073,7 +1122,8 @@ int bmp280_common_probe(struct device *dev,
        }
 
        data->regmap = regmap;
-       ret = regmap_read(regmap, BMP280_REG_ID, &chip_id);
+
+       ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id);
        if (ret < 0)
                return ret;
        if (chip_id != chip) {
@@ -1093,21 +1143,11 @@ int bmp280_common_probe(struct device *dev,
         * non-volatile memory during production". Let's read them out at probe
         * time once. They will not change.
         */
-       if (chip_id  == BMP180_CHIP_ID) {
-               ret = bmp180_read_calib(data, &data->calib.bmp180);
-               if (ret < 0) {
-                       dev_err(data->dev,
-                               "failed to read calibration coefficients\n");
-                       return ret;
-               }
-       } else if (chip_id == BMP280_CHIP_ID || chip_id == BME280_CHIP_ID) {
-               ret = bmp280_read_calib(data, &data->calib.bmp280, chip_id);
-               if (ret < 0) {
-                       dev_err(data->dev,
-                               "failed to read calibration coefficients\n");
-                       return ret;
-               }
-       }
+
+       ret = data->chip_info->read_calib(data);
+       if (ret < 0)
+               return dev_err_probe(data->dev, ret,
+                                    "failed to read calibration coefficients\n");
 
        /*
         * Attempt to grab an optional EOC IRQ - only the BMP085 has this