int bmp280_common_probe()

in pressure/bmp280-core.c [987:1138]

• 115 lines of code
• 21 McCabe index (conditional complexity)

int bmp280_common_probe(struct device *dev,
			struct regmap *regmap,
			unsigned int chip,
			const char *name,
			int irq)
{
	int ret;
	struct iio_dev *indio_dev;
	struct bmp280_data *data;
	unsigned int chip_id;
	struct gpio_desc *gpiod;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);
	mutex_init(&data->lock);
	data->dev = dev;

	indio_dev->name = name;
	indio_dev->channels = bmp280_channels;
	indio_dev->info = &bmp280_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	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;
		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;
		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;
		break;
	default:
		return -EINVAL;
	}

	/* Bring up regulators */
	regulator_bulk_set_supply_names(data->supplies,
					bmp280_supply_names,
					BMP280_NUM_SUPPLIES);

	ret = devm_regulator_bulk_get(dev,
				      BMP280_NUM_SUPPLIES, data->supplies);
	if (ret) {
		dev_err(dev, "failed to get regulators\n");
		return ret;
	}

	ret = regulator_bulk_enable(BMP280_NUM_SUPPLIES, data->supplies);
	if (ret) {
		dev_err(dev, "failed to enable regulators\n");
		return ret;
	}

	ret = devm_add_action_or_reset(dev, bmp280_regulators_disable,
				       data->supplies);
	if (ret)
		return ret;

	/* Wait to make sure we started up properly */
	usleep_range(data->start_up_time, data->start_up_time + 100);

	/* Bring chip out of reset if there is an assigned GPIO line */
	gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
	/* Deassert the signal */
	if (gpiod) {
		dev_info(dev, "release reset\n");
		gpiod_set_value(gpiod, 0);
	}

	data->regmap = regmap;
	ret = regmap_read(regmap, BMP280_REG_ID, &chip_id);
	if (ret < 0)
		return ret;
	if (chip_id != chip) {
		dev_err(dev, "bad chip id: expected %x got %x\n",
			chip, chip_id);
		return -EINVAL;
	}

	ret = data->chip_info->chip_config(data);
	if (ret < 0)
		return ret;

	dev_set_drvdata(dev, indio_dev);

	/*
	 * Some chips have calibration parameters "programmed into the devices'
	 * 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;
		}
	}

	/*
	 * Attempt to grab an optional EOC IRQ - only the BMP085 has this
	 * however as it happens, the BMP085 shares the chip ID of BMP180
	 * so we look for an IRQ if we have that.
	 */
	if (irq > 0 || (chip_id  == BMP180_CHIP_ID)) {
		ret = bmp085_fetch_eoc_irq(dev, name, irq, data);
		if (ret)
			return ret;
	}

	/* Enable runtime PM */
	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	/*
	 * Set autosuspend to two orders of magnitude larger than the
	 * start-up time.
	 */
	pm_runtime_set_autosuspend_delay(dev, data->start_up_time / 10);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_put(dev);

	ret = devm_add_action_or_reset(dev, bmp280_pm_disable, dev);
	if (ret)
		return ret;

	return devm_iio_device_register(dev, indio_dev);
}