Re: [PATCH 08/10 v4] iio: pressure: bmp280: add support for BMP085 EOC interrupt

[Jonathan Cameron <jic23@kernel.org>]

On 30/06/16 02:48, Linus Walleij wrote:
> The first version of this sensor, BMP085, supports sending an
> End-of-Conversion (EOC) interrupt. Add code to support this using
> a completion, in a similar vein as drivers/misc/bmp085.c does.
> 
> Make sure to check that we are given a rising edge, because the
> EOC line goes from low-to-high when the conversion is ready.
> 
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Bit of fuzz on this + one unrelated change that I've simply dropped.
If it matters to you send up a follow up patch.
> ---
> ChangeLog v3->v4:
> - Fix a few 058/085 typos
> ChangeLog v2->v3:
> - Fetch interrupt before registering IIO device
> - Factor out a separate BMP058 IRQ fetch function
> ChangeLog v1->v2:
> - Fix spelling mistakes
> - Rebase on all other stuff like changes in probe() etc
> ---
>  drivers/iio/pressure/bmp280-core.c | 92 ++++++++++++++++++++++++++++++++++----
>  drivers/iio/pressure/bmp280-i2c.c  |  3 +-
>  drivers/iio/pressure/bmp280-spi.c  |  3 +-
>  drivers/iio/pressure/bmp280.h      |  3 +-
>  4 files changed, 89 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 89ed608035f8..b2858fbc1049 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -27,6 +27,9 @@
>  #include <linux/iio/sysfs.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h> /* For irq_get_irq_data() */
> +#include <linux/completion.h>
>  
>  #include "bmp280.h"
>  
> @@ -34,6 +37,8 @@ struct bmp280_data {
>  	struct device *dev;
>  	struct mutex lock;
>  	struct regmap *regmap;
> +	struct completion done;
> +	bool use_eoc;
>  	const struct bmp280_chip_info *chip_info;
>  	struct regulator *vddd;
>  	struct regulator *vdda;
> @@ -595,16 +600,32 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
>  	unsigned int delay_us;
>  	unsigned int ctrl;
>  
> +	if (data->use_eoc)
> +		init_completion(&data->done);
> +
>  	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
>  	if (ret)
>  		return ret;
>  
> -	if (ctrl_meas == BMP180_MEAS_TEMP)
> -		delay_us = 4500;
> -	else
> -		delay_us = conversion_time_max[data->oversampling_press];
> -
> -	usleep_range(delay_us, delay_us + 1000);
> +	if (data->use_eoc) {
> +		/*
> +		 * If we have a completion interrupt, use it, wait up to
> +		 * 100ms. The longest conversion time listed is 76.5 ms for
> +		 * advanced resolution mode.
> +		 */
> +		ret = wait_for_completion_timeout(&data->done,
> +						  1 + msecs_to_jiffies(100));
> +		if (!ret)
> +			dev_err(data->dev, "timeout waiting for completion\n");
> +	} else {
> +		if (ctrl_meas == BMP180_MEAS_TEMP)
> +			delay_us = 4500;
> +		else
> +			delay_us =
> +				conversion_time_max[data->oversampling_press];
> +
> +		usleep_range(delay_us, delay_us + 1000);
> +	}
>  
>  	ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
>  	if (ret)
> @@ -846,10 +867,51 @@ static const struct bmp280_chip_info bmp180_chip_info = {
>  	.read_press = bmp180_read_press,
>  };
>  
> +static irqreturn_t bmp085_eoc_irq(int irq, void *d)
> +{
> +	struct bmp280_data *data = d;
> +
> +	complete(&data->done);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +int bmp085_fetch_eoc_irq(struct device *dev,
> +			 const char *name,
> +			 int irq,
> +			 struct bmp280_data *data)
> +{
> +	unsigned long irq_trig;
> +	int ret;
> +
> +	irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
> +	if (irq_trig != IRQF_TRIGGER_RISING) {
> +		dev_err(dev, "non-rising trigger given for EOC interrupt, "
> +			"trying to enforce it\n");
> +		irq_trig = IRQF_TRIGGER_RISING;
> +	}
> +	ret = devm_request_threaded_irq(dev,
> +			irq,
> +			bmp085_eoc_irq,
> +			NULL,
> +			irq_trig,
> +			name,
> +			data);
> +	if (ret) {
> +		/* Bail out without IRQ but keep the driver in place */
> +		dev_err(dev, "unable to request DRDY IRQ\n");
> +		return 0;
> +	}
> +
> +	data->use_eoc = true;
> +	return 0;
> +}
> +
>  int bmp280_common_probe(struct device *dev,
>  			struct regmap *regmap,
>  			unsigned int chip,
> -			const char *name)
> +			const char *name,
> +			int irq)
>  {
>  	int ret;
>  	struct iio_dev *indio_dev;
> @@ -948,10 +1010,22 @@ int bmp280_common_probe(struct device *dev,
>  
>  	dev_set_drvdata(dev, data);
>  
> +	/*
> +	 * 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)
> +			goto out_disable_vdda;
> +	}
> +
>  	ret = devm_iio_device_register(dev, indio_dev);
> -	if (ret)
> +	if (ret) {
> +		dev_err(dev, "unable to register IIO device\n");
Nothing whatsoever to do with this patch.
>  		goto out_disable_vdda;
> -
> +	}
>  	return 0;
>  
>  out_disable_vdda:
> diff --git a/drivers/iio/pressure/bmp280-i2c.c b/drivers/iio/pressure/bmp280-i2c.c
> index 7c70ee172bba..8cf8a900bdaa 100644
> --- a/drivers/iio/pressure/bmp280-i2c.c
> +++ b/drivers/iio/pressure/bmp280-i2c.c
> @@ -33,7 +33,8 @@ static int bmp280_i2c_probe(struct i2c_client *client,
>  	return bmp280_common_probe(&client->dev,
>  				   regmap,
>  				   id->driver_data,
> -				   id->name);
> +				   id->name,
> +				   client->irq);
>  }
>  
>  static int bmp280_i2c_remove(struct i2c_client *client)
> diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
> index 216e64b682bf..cd365ba74b68 100644
> --- a/drivers/iio/pressure/bmp280-spi.c
> +++ b/drivers/iio/pressure/bmp280-spi.c
> @@ -81,7 +81,8 @@ static int bmp280_spi_probe(struct spi_device *spi)
>  	return bmp280_common_probe(&spi->dev,
>  				   regmap,
>  				   id->driver_data,
> -				   id->name);
> +				   id->name,
> +				   spi->irq);
>  }
>  
>  static int bmp280_spi_remove(struct spi_device *spi)
> diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
> index b9fc28ce9428..573334b8e93b 100644
> --- a/drivers/iio/pressure/bmp280.h
> +++ b/drivers/iio/pressure/bmp280.h
> @@ -104,5 +104,6 @@ extern const struct regmap_config bmp280_regmap_config;
>  int bmp280_common_probe(struct device *dev,
>  			struct regmap *regmap,
>  			unsigned int chip,
> -			const char *name);
> +			const char *name,
> +			int irq);
>  int bmp280_common_remove(struct device *dev);
>