Add data ready trigger for hardware interrupts that signal
new, available measurement samples.
Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
Cc: Alison Schofield <amsfield22@xxxxxxxxx>
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@xxxxxxxxx>
---
Changes in v2:
- Define top half handler for interrupts which calls iio_trigger_poll
- Remove bottom half interrupt handler
- Add bool variable to store the state of the data ready trigger
- Remove threshold related macros and checks, as driver doesn't support
threshold interrupts yet
- Protect direct/buffered modes, by claiming direct mode in raw readings.
Reading the data from ALG_RESULT_DATA will clear the data ready bit and
will stop the nINT signal from being driven low. Therefore, disallow
raw readings while hardware interrupts are active.
- Rephrase commit message
Note:
It may not be necessary to protect direct mode when performing raw readings,
in that the data read may not be corrupted, but raw readings may "clear" the
interrupt(clear the data-ready bit and nINT signal) before the handler deals
with the interrupt, which doesn't seem like expected/acceptable behaviour.
Thoughts on this?
drivers/iio/chemical/ccs811.c | 87 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 86 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
index b59994d..c8ca1b9 100644
--- a/drivers/iio/chemical/ccs811.c
+++ b/drivers/iio/chemical/ccs811.c
@@ -23,6 +23,7 @@
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/module.h>
@@ -60,8 +61,12 @@
#define CCS811_MODE_IAQ_60SEC 0x30
#define CCS811_MODE_RAW_DATA 0x40
+#define CCS811_MEAS_MODE_INTERRUPT BIT(3)
+
#define CCS811_VOLTAGE_MASK 0x3FF
+#define CCS811_IRQ_NAME "ccs811_irq"
+
struct ccs811_reading {
__be16 co2;
__be16 voc;
@@ -74,6 +79,8 @@ struct ccs811_data {
struct i2c_client *client;
struct mutex lock; /* Protect readings */
struct ccs811_reading buffer;
+ struct iio_trigger *drdy_trig;
+ bool drdy_trig_on;
};
static const struct iio_chan_spec ccs811_channels[] = {
@@ -194,10 +201,14 @@ static int ccs811_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
mutex_lock(&data->lock);
ret = ccs811_get_measurement(data);
if (ret < 0) {
mutex_unlock(&data->lock);
+ iio_device_release_direct_mode(indio_dev);
return ret;
}
@@ -229,6 +240,7 @@ static int ccs811_read_raw(struct iio_dev *indio_dev,
ret = -EINVAL;
}
mutex_unlock(&data->lock);
+ iio_device_release_direct_mode(indio_dev);
return ret;
@@ -274,6 +286,32 @@ static int ccs811_read_raw(struct iio_dev *indio_dev,
.driver_module = THIS_MODULE,
};
+static int ccs811_set_trigger_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct ccs811_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, CCS811_MEAS_MODE);
+ if (ret < 0)
+ return ret;
+
+ if (state)
+ ret |= CCS811_MEAS_MODE_INTERRUPT;
+ else
+ ret &= ~CCS811_MEAS_MODE_INTERRUPT;
+
+ data->drdy_trig_on = state;
+
+ return i2c_smbus_write_byte_data(data->client, CCS811_MEAS_MODE, ret);
+}
+
+static const struct iio_trigger_ops ccs811_trigger_ops = {
+ .set_trigger_state = ccs811_set_trigger_state,
+ .owner = THIS_MODULE,
+};
+
static irqreturn_t ccs811_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
@@ -299,6 +337,17 @@ static irqreturn_t ccs811_trigger_handler(int irq, void *p)
return IRQ_HANDLED;
}
+static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct ccs811_data *data = iio_priv(indio_dev);
+
+ if (data->drdy_trig_on)
+ iio_trigger_poll(data->drdy_trig);
+
+ return IRQ_HANDLED;
+}
+
static int ccs811_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -347,16 +396,48 @@ static int ccs811_probe(struct i2c_client *client,
indio_dev->dev.parent = &client->dev;
indio_dev->name = id->name;
indio_dev->info = &ccs811_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ccs811_channels;
indio_dev->num_channels = ARRAY_SIZE(ccs811_channels);
+ if (client->irq > 0) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ ccs811_data_rdy_trigger_poll,
+ NULL,
+ IRQF_TRIGGER_FALLING |
+ IRQF_ONESHOT,
+ CCS811_IRQ_NAME, indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "irq request error %d\n", -ret);
+ goto err_poweroff;
+ }
+
+ data->drdy_trig = devm_iio_trigger_alloc(&client->dev,
+ "%s-dev%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (!data->drdy_trig) {
+ ret = -ENOMEM;
+ goto err_poweroff;
+ }
+
+ data->drdy_trig->dev.parent = &client->dev;
+ data->drdy_trig->ops = &ccs811_trigger_ops;
+ iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
+ indio_dev->trig = data->drdy_trig;
+ iio_trigger_get(indio_dev->trig);
+ ret = iio_trigger_register(data->drdy_trig);
+ if (ret)
+ goto err_poweroff;
+ }
+
ret = iio_triggered_buffer_setup(indio_dev, NULL,
ccs811_trigger_handler, NULL);
if (ret < 0) {
dev_err(&client->dev, "triggered buffer setup failed\n");
- goto err_poweroff;
+ goto err_trigger_unregister;
}
ret = iio_device_register(indio_dev);
@@ -368,6 +449,8 @@ static int ccs811_probe(struct i2c_client *client,
err_buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+ iio_trigger_unregister(data->drdy_trig);
err_poweroff:
i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);
@@ -377,9 +460,11 @@ static int ccs811_probe(struct i2c_client *client,
static int ccs811_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct ccs811_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
+ iio_trigger_unregister(data->drdy_trig);
return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
CCS811_MODE_IDLE);
--
1.9.1
--
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