Re: [PATCH v6 4/9] iio: pressure: bmp280: simplify driver initialization logic
From: Jonathan Cameron
Date: Sat Sep 17 2022 - 09:16:15 EST
On Tue, 13 Sep 2022 01:47:31 +0200
Angel Iglesias <ang.iglesiasg@xxxxxxxxx> wrote:
> 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@xxxxxxxxxx>
> Signed-off-by: Angel Iglesias <ang.iglesiasg@xxxxxxxxx>
Applied
> ---
> drivers/iio/pressure/bmp280-core.c | 126 +++++++++++++++++++----------
> 1 file changed, 83 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 4793bcd9f0b3..203623d32032 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -109,19 +109,28 @@ 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 *);
> };
>
> /*
> @@ -148,15 +157,10 @@ 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;
>
>
> @@ -188,6 +192,25 @@ 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
> @@ -195,8 +218,6 @@ 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) {
> @@ -631,15 +652,32 @@ 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)
> @@ -661,19 +699,27 @@ 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)
> @@ -741,9 +787,9 @@ 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;
> @@ -909,17 +955,24 @@ 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)
> @@ -986,6 +1039,7 @@ 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;
> @@ -1007,30 +1061,25 @@ 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,
> @@ -1067,7 +1116,8 @@ 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) {
> @@ -1087,21 +1137,11 @@ 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