On 22/06/16 21:53, 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@xxxxxxxxxx>
Rather obvious race condition in probe..
> ---
> ChangeLog v1->v2:
> - Fix spelling mistakes
> ---
> drivers/iio/pressure/bmp280-core.c | 83 ++++++++++++++++++++++++++++++++++----
> drivers/iio/pressure/bmp280-i2c.c | 3 +-
> drivers/iio/pressure/bmp280-spi.c | 3 +-
> drivers/iio/pressure/bmp280.h | 3 +-
> 4 files changed, 81 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 733ef3c08102..7b2a03d6fd1d 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -26,6 +26,9 @@
> #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"
>
> @@ -33,6 +36,8 @@ 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;
> @@ -593,16 +598,32 @@ 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)
> @@ -844,16 +865,28 @@ static const struct bmp280_chip_info bmp180_chip_info = {
> .read_press = bmp180_read_press,
> };
>
> +static irqreturn_t bmp058_eoc_irq(int irq, void *d)
> +{
> + struct bmp280_data *data = d;
> +
> + complete(&data->done);
> +
> + return IRQ_HANDLED;
> +}
> +
> +
> 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;
> struct bmp280_data *data;
> unsigned int chip_id;
> struct gpio_desc *gpiod;
> + unsigned long irq_trig;
>
> indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> if (!indio_dev)
> @@ -937,5 +970,39 @@ int bmp280_common_probe(struct device *dev,
> if (ret < 0)
> return ret;
>
> - return devm_iio_device_register(dev, indio_dev);
> + ret = devm_iio_device_register(dev, indio_dev);
You just exposed the userspace interface here.... Yet (see below)
> + if (ret) {
> + dev_err(dev, "unable to register IIO device\n");
> + return ret;
> + }
> +
> + /*
> + * Attempt to grab an optional EOC IRQ - only the BMP058 has this
> + * however as it happens, the BMP058 shares the chip ID of BMP180
> + * so we look for an IRQ if we have that.
> + */
> + if (irq <= 0 || (chip_id != BMP180_CHIP_ID))
> + return 0;
> +
> + 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,
> + bmp058_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;
> + }
A necessary interrupt isn't available until here. Please reorder.
The register call for userspace (and for that matter inkernel users) must
be made only one everything else is ready.
> +
> + data->use_eoc = true;
> + return 0;
> }
> diff --git a/drivers/iio/pressure/bmp280-i2c.c b/drivers/iio/pressure/bmp280-i2c.c
> index a981670e5dc0..b9a2562e8a7e 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 const struct acpi_device_id bmp280_acpi_i2c_match[] = {
> diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
> index 2b9955f48d58..05ddf2ee7519 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 const struct of_device_id bmp280_of_spi_match[] = {
> diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
> index acb40de2f581..9dee048b5a74 100644
> --- a/drivers/iio/pressure/bmp280.h
> +++ b/drivers/iio/pressure/bmp280.h
> @@ -104,4 +104,5 @@ 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);
>
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