On Thu, 17 Aug 2017 14:39:26 +0300
Narcisa Ana Maria Vasile <narcisaanamaria12@xxxxxxxxx> wrote:
> Add data ready trigger for hardware interrupts that notify us when
> new measurement samples are available.
>
> Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@xxxxxxxxx>
> ---
> Note: This patch depends on:
> [PATCH v2] iio: chemical: ccs811: Add triggered buffer support
>
> drivers/iio/chemical/ccs811.c | 93 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 92 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
> index b59994d..0fd617a 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 +61,13 @@
> #define CCS811_MODE_IAQ_60SEC 0x30
> #define CCS811_MODE_RAW_DATA 0x40
>
> +#define CCS811_MEAS_MODE_THRESH BIT(2)
> +#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 +80,7 @@ struct ccs811_data {
> struct i2c_client *client;
> struct mutex lock; /* Protect readings */
> struct ccs811_reading buffer;
> + struct iio_trigger *drdy_trig;
> };
>
> static const struct iio_chan_spec ccs811_channels[] = {
> @@ -274,6 +281,54 @@ 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;
> +
> + if (data->drdy_trig == trig)
> + ret &= ~CCS811_MEAS_MODE_THRESH;
> +
> + 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_interrupt_handler(int irq, void *p)
> +{
How does this differ from the interrupt handler that was added in
the previous patch?
For a dataready trigger I'd be expecting to see some calls into
the triggering core.
In particular an iio_trigger_poll call.
It is fine to not use the trigger infrastructure at all if the
device doesn'g fit. However as far as I can tell this one does.
> + struct iio_dev *indio_dev = p;
> + struct ccs811_data *data = iio_priv(indio_dev);
> + u16 buf[8]; /* u16 eCO2 + u16 TVOC + padding + 8 byte timestamp */
> + int ret;
> +
> + ret = i2c_smbus_read_i2c_block_data(data->client,
> + CCS811_ALG_RESULT_DATA, 4,
> + (u8 *)&buf);
> + if (ret != 4) {
> + dev_err(&data->client->dev, "cannot read sensor data\n");
> + goto err;
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, buf,
> + iio_get_time_ns(indio_dev));
> +err:
> + return IRQ_HANDLED;
> +}
> +
> static irqreturn_t ccs811_trigger_handler(int irq, void *p)
> {
> struct iio_poll_func *pf = p;
> @@ -347,16 +402,48 @@ 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,
> + NULL,
> + ccs811_interrupt_handler,
> + 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 +455,8 @@ 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 +466,11 @@ 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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