[PATCH v3 6/7] iio: pressure: bmp280: Add data ready trigger support

Vasileios Amoiridis
2024-08-23T18:17:27Z

The BMP3xx and BMP5xx sensors have an interrupt pin which can be used as
a trigger for when there are data ready in the sensor for pick up.

This use case is used along with NORMAL_MODE in the sensor, which allows
the sensor to do consecutive measurements depending on the ODR rate value.

The trigger pin can be configured to be open-drain or push-pull and either
rising or falling edge.

No support is added yet for interrupts for FIFO, WATERMARK and out of range
values.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
drivers/iio/pressure/bmp280-core.c | 252 ++++++++++++++++++++++++++++-
drivers/iio/pressure/bmp280.h | 21 +++
2 files changed, 269 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index e1336aeceec0..f5268a13bfdb 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -37,12 +37,14 @@
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/pm_runtime.h>
+#include <linux/property.h>
#include <linux/random.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

@@ -1271,6 +1273,74 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p)
return IRQ_HANDLED;
}

+static int __bmp280_trigger_probe(struct iio_dev *indio_dev,
+ const struct iio_trigger_ops *trigger_ops,
+ int (*int_config)(struct bmp280_data *data),
+ irqreturn_t (*irq_thread_handler)(int irq, void *p))
+{
+ struct bmp280_data *data = iio_priv(indio_dev);
+ struct fwnode_handle *fwnode;
+ int ret, irq, irq_type;
+ struct irq_data *desc;
+
+ fwnode = dev_fwnode(data->dev);
+ if (!fwnode)
+ return -ENODEV;
+
+ irq = fwnode_irq_get(fwnode, 0);
+ if (!irq)
+ return dev_err_probe(data->dev, -ENODEV,
+ "No interrupt found.\n");
+
+ desc = irq_get_irq_data(irq);
+ if (!desc)
+ return -EINVAL;
+
+ irq_type = irqd_get_trigger_type(desc);
+ switch (irq_type) {
+ case IRQF_TRIGGER_RISING:
+ data->trig_active_high = true;
+ break;
+ case IRQF_TRIGGER_FALLING:
+ data->trig_active_high = false;
+ break;
+ default:
+ return dev_err_probe(data->dev, -EINVAL,
+ "Invalid interrupt type specified.\n");
+ }
+
+ data->trig_open_drain = fwnode_property_read_bool(fwnode,
+ "int-open-drain");
+
+ ret = int_config(data);
+ if (ret)
+ return ret;
+
+ data->trig = devm_iio_trigger_alloc(data->dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!data->trig)
+ return -ENOMEM;
+
+ data->trig->ops = trigger_ops;
+ iio_trigger_set_drvdata(data->trig, data);
+
+ ret = devm_request_threaded_irq(data->dev, irq, NULL,
+ irq_thread_handler, IRQF_ONESHOT,
+ indio_dev->name, indio_dev);
+ if (ret)
+ return dev_err_probe(data->dev, ret, "request irq failed.\n");
+
+ ret = devm_iio_trigger_register(data->dev, data->trig);
+ if (ret)
+ return dev_err_probe(data->dev, ret,
+ "iio trigger register failed.\n");
+
+ indio_dev->trig = iio_trigger_get(data->trig);
+
+ return 0;
+}
+
static const u8 bme280_chip_ids[] = { BME280_CHIP_ID };
static const int bme280_humid_coeffs[] = { 1000, 1024 };

@@ -1769,6 +1839,85 @@ static int bmp380_chip_config(struct bmp280_data *data)
return 0;
}

+static void bmp380_trigger_reenable(struct iio_trigger *trig)
+{
+ struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+ unsigned int tmp;
+ int ret;
+
+ ret = regmap_read(data->regmap, BMP380_REG_INT_STATUS, &tmp);
+ if (ret)
+ dev_err(data->dev, "Failed to reset interrupt\n");
+}
+
+static int bmp380_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = regmap_update_bits(data->regmap, BMP380_REG_INT_CONTROL,
+ BMP380_INT_CTRL_DRDY_EN,
+ FIELD_PREP(BMP380_INT_CTRL_DRDY_EN,
+ state ? 1 : 0));
+ if (ret) {
+ dev_err(data->dev, "Could not enable/disable interrupt\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct iio_trigger_ops bmp380_trigger_ops = {
+ .set_trigger_state = &bmp380_data_rdy_trigger_set_state,
+ .reenable = &bmp380_trigger_reenable,
+};
+
+static int bmp380_int_config(struct bmp280_data *data)
+{
+ int ret, int_cfg = FIELD_PREP(BMP380_INT_CTRL_OPEN_DRAIN,
+ data->trig_open_drain) |
+ FIELD_PREP(BMP380_INT_CTRL_LEVEL,
+ data->trig_active_high);
+
+ ret = regmap_update_bits(data->regmap, BMP380_REG_INT_CONTROL,
+ BMP380_INT_CTRL_SETTINGS_MASK, int_cfg);
+ if (ret) {
+ dev_err(data->dev, "Could not set interrupt settings\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static irqreturn_t bmp380_irq_thread_handler(int irq, void *p)
+{
+ struct iio_dev *indio_dev = p;
+ struct bmp280_data *data = iio_priv(indio_dev);
+ unsigned int int_ctrl;
+ int ret;
+
+ scoped_guard(mutex, &data->lock) {
+ ret = regmap_read(data->regmap, BMP380_REG_INT_STATUS, &int_ctrl);
+ if (ret)
+ return IRQ_NONE;
+ }
+
+ if (FIELD_GET(BMP380_INT_STATUS_DRDY, int_ctrl))
+ iio_trigger_poll_nested(data->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int bmp380_trigger_probe(struct iio_dev *indio_dev)
+{
+ return __bmp280_trigger_probe(indio_dev, &bmp380_trigger_ops,
+ bmp380_int_config,
+ bmp380_irq_thread_handler);
+}
+
static irqreturn_t bmp380_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
@@ -1863,6 +2012,7 @@ const struct bmp280_chip_info bmp380_chip_info = {
.wait_conv = bmp380_wait_conv,
.preinit = bmp380_preinit,

+ .trigger_probe = bmp380_trigger_probe,
.trigger_handler = bmp380_trigger_handler,
};
EXPORT_SYMBOL_NS(bmp380_chip_info, IIO_BMP280);
@@ -2401,6 +2551,92 @@ static int bmp580_chip_config(struct bmp280_data *data)
return 0;
}

+static void bmp580_trigger_reenable(struct iio_trigger *trig)
+{
+ struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+ unsigned int tmp;
+ int ret;
+
+ ret = regmap_read(data->regmap, BMP580_REG_INT_STATUS, &tmp);
+ if (ret)
+ dev_err(data->dev, "Failed to reset interrupt\n");
+}
+
+static int bmp580_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct bmp280_data *data = iio_trigger_get_drvdata(trig);
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ ret = regmap_update_bits(data->regmap, BMP580_REG_INT_CONFIG,
+ BMP580_INT_CONFIG_INT_EN,
+ FIELD_PREP(BMP580_INT_CONFIG_INT_EN,
+ state ? 1 : 0));
+ if (ret) {
+ dev_err(data->dev, "Could not enable/disable interrupt\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct iio_trigger_ops bmp580_trigger_ops = {
+ .set_trigger_state = &bmp580_data_rdy_trigger_set_state,
+ .reenable = &bmp580_trigger_reenable,
+};
+
+static int bmp580_int_config(struct bmp280_data *data)
+{
+ int ret, int_cfg = FIELD_PREP(BMP580_INT_CONFIG_OPEN_DRAIN,
+ data->trig_open_drain) |
+ FIELD_PREP(BMP580_INT_CONFIG_LEVEL,
+ data->trig_active_high);
+
+ ret = regmap_update_bits(data->regmap, BMP580_REG_INT_CONFIG,
+ BMP580_INT_CONFIG_MASK, int_cfg);
+ if (ret) {
+ dev_err(data->dev, "Could not set interrupt settings\n");
+ return ret;
+ }
+
+ ret = regmap_set_bits(data->regmap, BMP580_REG_INT_SOURCE,
+ BMP580_INT_SOURCE_DRDY);
+ if (ret) {
+ dev_err(data->dev, "Could not set interrupt source\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static irqreturn_t bmp580_irq_thread_handler(int irq, void *p)
+{
+ struct iio_dev *indio_dev = p;
+ struct bmp280_data *data = iio_priv(indio_dev);
+ unsigned int int_ctrl;
+ int ret;
+
+ scoped_guard(mutex, &data->lock) {
+ ret = regmap_read(data->regmap, BMP580_REG_INT_STATUS, &int_ctrl);
+ if (ret)
+ return IRQ_NONE;
+ }
+
+ if (FIELD_GET(BMP580_INT_STATUS_DRDY_MASK, int_ctrl))
+ iio_trigger_poll_nested(data->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int bmp580_trigger_probe(struct iio_dev *indio_dev)
+{
+ return __bmp280_trigger_probe(indio_dev, &bmp580_trigger_ops,
+ bmp580_int_config,
+ bmp580_irq_thread_handler);
+}
+
static irqreturn_t bmp580_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
@@ -2477,6 +2713,7 @@ const struct bmp280_chip_info bmp580_chip_info = {
.wait_conv = bmp580_wait_conv,
.preinit = bmp580_preinit,

+ .trigger_probe = bmp580_trigger_probe,
.trigger_handler = bmp580_trigger_handler,
};
EXPORT_SYMBOL_NS(bmp580_chip_info, IIO_BMP280);
@@ -3024,10 +3261,17 @@ int bmp280_common_probe(struct device *dev,
* 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;
+ if (irq > 0) {
+ if (chip_id == BMP180_CHIP_ID) {
+ ret = bmp085_fetch_eoc_irq(dev, name, irq, data);
+ if (ret)
+ return ret;
+ }
+ if (data->chip_info->trigger_probe) {
+ ret = data->chip_info->trigger_probe(indio_dev);
+ if (ret)
+ return ret;
+ }
}

ret = data->chip_info->set_mode(data, BMP280_SLEEP);
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index c9840b8d58b0..0c32b6430677 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -55,8 +55,17 @@
#define BMP580_CMD_NVM_WRITE_SEQ_1 0xA0
#define BMP580_CMD_SOFT_RESET 0xB6

+#define BMP580_INT_STATUS_DRDY_MASK BIT(0)
#define BMP580_INT_STATUS_POR_MASK BIT(4)

+#define BMP580_INT_SOURCE_DRDY BIT(0)
+
+#define BMP580_INT_CONFIG_MASK GENMASK(3, 0)
+#define BMP580_INT_CONFIG_LATCH BIT(0)
+#define BMP580_INT_CONFIG_LEVEL BIT(1)
+#define BMP580_INT_CONFIG_OPEN_DRAIN BIT(2)
+#define BMP580_INT_CONFIG_INT_EN BIT(3)
+
#define BMP580_STATUS_CORE_RDY_MASK BIT(0)
#define BMP580_STATUS_NVM_RDY_MASK BIT(1)
#define BMP580_STATUS_NVM_ERR_MASK BIT(2)
@@ -175,6 +184,14 @@
#define BMP380_TEMP_MEAS_OFFSET 163
#define BMP380_PRESS_MEAS_OFFSET 392

+#define BMP380_INT_STATUS_DRDY BIT(3)
+
+#define BMP380_INT_CTRL_SETTINGS_MASK GENMASK(2, 0)
+#define BMP380_INT_CTRL_OPEN_DRAIN BIT(0)
+#define BMP380_INT_CTRL_LEVEL BIT(1)
+#define BMP380_INT_CTRL_LATCH BIT(2)
+#define BMP380_INT_CTRL_DRDY_EN BIT(6)
+
#define BMP380_MIN_TEMP -4000
#define BMP380_MAX_TEMP 8500
#define BMP380_MIN_PRES 3000000
@@ -406,6 +423,9 @@ struct bmp280_data {
struct regmap *regmap;
struct completion done;
bool use_eoc;
+ bool trig_open_drain;
+ bool trig_active_high;
+ struct iio_trigger *trig;
const struct bmp280_chip_info *chip_info;
union {
struct bmp180_calib bmp180;
@@ -510,6 +530,7 @@ struct bmp280_chip_info {
int (*set_mode)(struct bmp280_data *data, enum bmp280_op_mode mode);
int (*wait_conv)(struct bmp280_data *data);

+ int (*trigger_probe)(struct iio_dev *indio_dev);
irqreturn_t (*trigger_handler)(int irq, void *p);
};

--
2.25.1