iio: chemical: ccs811: Add support for data ready trigger

Add data ready trigger for hardware interrupts that signal
new, available measurement samples.

Cc: Daniel Baluta <daniel.baluta@gmail.com>
Cc: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
index 6f57cb15c513079b9e1610b1e08b7fb57984f400..97bce8345c6a88b84269dce60a04c6df6100801e 100644 (file)
--- a/drivers/iio/chemical/ccs811.c
+++ b/drivers/iio/chemical/ccs811.c
@@ -22,6 +22,7 @@
 #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>
@@ -59,6 +60,8 @@
 #define CCS811_MODE_IAQ_60SEC  0x30
 #define CCS811_MODE_RAW_DATA   0x40
 
+#define CCS811_MEAS_MODE_INTERRUPT     BIT(3)
+
 #define CCS811_VOLTAGE_MASK    0x3FF
 
 struct ccs811_reading {
@@ -73,6 +76,8 @@ 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[] = {
@@ -193,10 +198,14 @@ 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;
                }
 
@@ -228,6 +237,7 @@ 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;
 
@@ -272,6 +282,31 @@ static const struct iio_info ccs811_info = {
        .read_raw = ccs811_read_raw,
 };
 
+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,
+};
+
 static irqreturn_t ccs811_trigger_handler(int irq, void *p)
 {
        struct iio_poll_func *pf = p;
@@ -297,6 +332,17 @@ err:
        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)
 {
@@ -345,16 +391,48 @@ 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", 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);
@@ -366,6 +444,9 @@ static int ccs811_probe(struct i2c_client *client,
 
 err_buffer_cleanup:
        iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+       if (data->drdy_trig)
+               iio_trigger_unregister(data->drdy_trig);
 err_poweroff:
        i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);
 
@@ -375,9 +456,12 @@ err_poweroff:
 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);
+       if (data->drdy_trig)
+               iio_trigger_unregister(data->drdy_trig);
 
        return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
                                         CCS811_MODE_IDLE);