On Fri, Aug 18, 2017 at 10:16 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> 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?
Shouldn't be any difference. Perhaps, a check to see if the interrupt was
really for us.
But for the moment we can use ccs811_trigger_handler instead of this
cc2811_interrupt_handler.
>
> For a dataready trigger I'd be expecting to see some calls into
> the triggering core.
>
> In particular an iio_trigger_poll call.
>
Yup, this means adding a top half handler 4th parameter of
devm_request_threaded_irq,
This will call iio_trigger_poll which in turn will call ccs811_trigger_handler.
Then, the 5th parameter of devm_request_threaded_irq (the bottom half)
it will be used
for handling events.
> 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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