iio: pressure: bmp280: add support for BMP085 EOC interrupt

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 43bd0b07619cdf1b12d98c0a6a049247bef98059..3ebd84f06e36609f85292e3a13721ad9505d5c5f 100644 (file)
--- 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;
+}
+
+static 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;
@@ -948,6 +1010,17 @@ int bmp280_common_probe(struct device *dev,
 
        dev_set_drvdata(dev, indio_dev);
 
+       /*
+        * 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 = iio_device_register(indio_dev);
        if (ret)
                goto out_disable_vdda;

diff --git a/drivers/iio/pressure/bmp280-i2c.c b/drivers/iio/pressure/bmp280-i2c.c
index 7c70ee172bba9e37ab20d72450c62b5eb3924816..8cf8a900bdaab533fab0c841b14a0a5ca1de874e 100644 (file)
--- 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 216e64b682bf2a74d0a46ba080851437a0ff94b2..cd365ba74b68f0a56a05cd3ab603440e1c6ac00d 100644 (file)
--- 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 b9fc28ce94288a10b91529f4536971fe053d99c9..573334b8e93b6161a9c407192b5af5c6f889da82 100644 (file)
--- 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);