On Sat, Mar 13, 2021 at 8:29 AM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Wed, 10 Mar 2021 17:41:14 -0800
> Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
>
> > fixes commit 2e2366c2d141 ("iio: cros_ec: unify hw fifo attributes into the core file")
> > fixes commit 165aea80e2e2 ("iio: cros_ec: use devm_iio_triggered_buffer_setup_ext()")
>
> I'm lost on what the purpose of this patch is. Could you describe how the
> above 2 patches broken the driver?
>
> >
> > 1. Instead of adding has_fw_fifo, deduct it from the configuration:
> > - EC must support FIFO (EC_FEATURE_MOTION_SENSE_FIFO) set.
> > - sensors send data a regular interval (accelerometer, gyro,
> > magnetomer, barometer, light sensor).
> > - "Legacy accelerometer" is only present on EC without FIFO, so we don't
> > need to set buffer attributes.
> >
> > 2. devm_iio_triggered_buffer_setup_ext() does not need to be called when
> > EC does not support FIFO, as there is no FIFO to manage.
>
> Whilst true, that point is rather trivial as the non _ext() version
> just calls that function with last parameter set to NULL.
> I guess from a readability point of view, calling the non extended
> version makes sense.
>
> >
> > 3. Create a triggered buffer with devm_iio_triggered_buffer_setup_ext() when
> > the EC support FIFO as it is the only clean way to set the
> > buffer extended attributes.
> > Add a slim trigger to be sure the samples can flow via callback from the
> > EC FIFO to the IIO buffer.
>
> There are some issues with doing that which make it somewhat fiddly (see inline).
>
> Jonathan
>
>
> >
> > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> > ---
> > Changes since v3:
> > Remove Change-Id.
> >
> > Changes since v2:
> > Remove include of buffer_impl.
> > Rebase on top of kernel/git/jic23/iio.git testing branch.
> >
> > Changes since v1:
> > Use a slim trigger when EC supports FIFO, to use
> > devm_iio_triggered_buffer_setup_ext().
> >
> > drivers/iio/accel/cros_ec_accel_legacy.c | 2 +-
> > .../cros_ec_sensors/cros_ec_lid_angle.c | 3 +-
> > .../common/cros_ec_sensors/cros_ec_sensors.c | 3 +-
> > .../cros_ec_sensors/cros_ec_sensors_core.c | 56 ++++++++++++-------
> > drivers/iio/light/cros_ec_light_prox.c | 3 +-
> > drivers/iio/pressure/cros_ec_baro.c | 3 +-
> > .../linux/iio/common/cros_ec_sensors_core.h | 3 +-
> > 7 files changed, 41 insertions(+), 32 deletions(-)
> >
> > diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c
> > index 8f1232c38e0d7..b6f3471b62dcf 100644
> > --- a/drivers/iio/accel/cros_ec_accel_legacy.c
> > +++ b/drivers/iio/accel/cros_ec_accel_legacy.c
> > @@ -215,7 +215,7 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
> > return -ENOMEM;
> >
> > ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
> > - cros_ec_sensors_capture, NULL, false);
> > + cros_ec_sensors_capture, NULL);
> > if (ret)
> > return ret;
> >
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > index 752f59037715b..af801e203623e 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > @@ -97,8 +97,7 @@ static int cros_ec_lid_angle_probe(struct platform_device *pdev)
> > if (!indio_dev)
> > return -ENOMEM;
> >
> > - ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL,
> > - NULL, false);
> > + ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL, NULL);
> > if (ret)
> > return ret;
> >
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > index dee1191de7528..376a5b30010ae 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > @@ -236,8 +236,7 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
> >
> > ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
> > cros_ec_sensors_capture,
> > - cros_ec_sensors_push_data,
> > - true);
> > + cros_ec_sensors_push_data);
> > if (ret)
> > return ret;
> >
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > index f8824afe595e4..7b7a98922892d 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > @@ -12,6 +12,7 @@
> > #include <linux/iio/iio.h>
> > #include <linux/iio/kfifo_buf.h>
> > #include <linux/iio/sysfs.h>
> > +#include <linux/iio/trigger.h>
> > #include <linux/iio/trigger_consumer.h>
> > #include <linux/iio/triggered_buffer.h>
> > #include <linux/kernel.h>
> > @@ -240,7 +241,6 @@ static void cros_ec_sensors_core_clean(void *arg)
> > * for backward compatibility.
> > * @push_data: function to call when cros_ec_sensorhub receives
> > * a sample for that sensor.
> > - * @has_hw_fifo: Set true if this device has/uses a HW FIFO
> > *
> > * Return: 0 on success, -errno on failure.
> > */
> > @@ -248,8 +248,7 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> > struct iio_dev *indio_dev,
> > bool physical_device,
> > cros_ec_sensors_capture_t trigger_capture,
> > - cros_ec_sensorhub_push_data_cb_t push_data,
> > - bool has_hw_fifo)
> > + cros_ec_sensorhub_push_data_cb_t push_data)
> > {
> > struct device *dev = &pdev->dev;
> > struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
> > @@ -329,19 +328,41 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> > }
> >
> > if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
> > + struct iio_trigger *trig;
> > +
> > /*
> > - * Create a software buffer, feed by the EC FIFO.
> > - * We can not use trigger here, as events are generated
> > - * as soon as sample_frequency is set.
> > + * Create a triggered buffer to be able to trigger data
> > + * gathering manually, but by default, samples come from
> > + * the EC FIFO.
> > */
> > - ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
> > - INDIO_BUFFER_SOFTWARE,
> > - NULL);
> > + ret = devm_iio_triggered_buffer_setup_ext(dev, indio_dev,
> > + NULL, trigger_capture, NULL,
> > + cros_ec_sensor_fifo_attributes);
> > if (ret)
> > return ret;
> >
> > - ret = cros_ec_sensorhub_register_push_data(
> > - sensor_hub, sensor_platform->sensor_num,
> > + /*
> > + * Register a trigger as plug to allow samples from the
> > + * FIFO to flow.
> > + * When cros-ec-sensor-ring is present, samples produced
> > + * by the EC FIFO are directed to that ring only.
> > + */
> > + trig = devm_iio_trigger_alloc(dev, "cros_ec%d-dev%d",
> > + sensor_platform->sensor_num, indio_dev->id);
> > + if (!trig)
> > + return -ENOMEM;
> > +
> > + ret = devm_iio_trigger_register(dev, trig);
> > + if (ret < 0)
> > + return ret;
> > + indio_dev->trig = iio_trigger_get(trig);
> Whilst this is a valid way of doing things, we normally only bother if the driver
> is happy for that trigger to be changed and will function correctly with
> a different trigger.
>
> If the driver only supports one trigger, we do have iio_trigger_set_immutable()
> Do you also need to stop other drivers using the trigger as it's a fake and
> hence won't ever actually do result in the triggers being polled?
> For that you need to set the validate_device() callback in the trigger ops.
>
> It's a bit pointless though, so unless you have a strong reason, I think the
> approach of just defining the devm_iio_kfifo_setup_buffer_ext() as Alex
> suggested is cleaner.
I am fine devm_iio_kfifo_setup_buffer_ext(), it is indeed cleaner.
Gwendal.
>
> > +
> > + /*
> > + * Register the callback to use when a sensor sample is
> > + * coming from the EC FIFO.
> > + */
> > + ret = cros_ec_sensorhub_register_push_data(sensor_hub,
> > + sensor_platform->sensor_num,
> > indio_dev, push_data);
> > if (ret)
> > return ret;
> > @@ -355,21 +376,14 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> > ret = iio_device_set_clock(indio_dev, CLOCK_BOOTTIME);
> > if (ret)
> > return ret;
> > - } else {
> > - const struct attribute **fifo_attrs;
> > -
> > - if (has_hw_fifo)
> > - fifo_attrs = cros_ec_sensor_fifo_attributes;
> > - else
> > - fifo_attrs = NULL;
> >
> > + } else {
> > /*
> > * The only way to get samples in buffer is to set a
> > * software trigger (systrig, hrtimer).
> > */
> > - ret = devm_iio_triggered_buffer_setup_ext(
> > - dev, indio_dev, NULL, trigger_capture,
> > - NULL, fifo_attrs);
> > + ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
> > + NULL, trigger_capture, NULL);
> > if (ret)
> > return ret;
> > }
> > diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
> > index 75d6b5fcf2cc4..de472f23d1cba 100644
> > --- a/drivers/iio/light/cros_ec_light_prox.c
> > +++ b/drivers/iio/light/cros_ec_light_prox.c
> > @@ -182,8 +182,7 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
> >
> > ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
> > cros_ec_sensors_capture,
> > - cros_ec_sensors_push_data,
> > - true);
> > + cros_ec_sensors_push_data);
> > if (ret)
> > return ret;
> >
> > diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
> > index aa043cb9ac426..2f882e1094232 100644
> > --- a/drivers/iio/pressure/cros_ec_baro.c
> > +++ b/drivers/iio/pressure/cros_ec_baro.c
> > @@ -139,8 +139,7 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
> >
> > ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
> > cros_ec_sensors_capture,
> > - cros_ec_sensors_push_data,
> > - true);
> > + cros_ec_sensors_push_data);
> > if (ret)
> > return ret;
> >
> > diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
> > index c9b80be82440f..7ce8a8adad587 100644
> > --- a/include/linux/iio/common/cros_ec_sensors_core.h
> > +++ b/include/linux/iio/common/cros_ec_sensors_core.h
> > @@ -96,8 +96,7 @@ struct platform_device;
> > int cros_ec_sensors_core_init(struct platform_device *pdev,
> > struct iio_dev *indio_dev, bool physical_device,
> > cros_ec_sensors_capture_t trigger_capture,
> > - cros_ec_sensorhub_push_data_cb_t push_data,
> > - bool has_hw_fifo);
> > + cros_ec_sensorhub_push_data_cb_t push_data);
> >
> > irqreturn_t cros_ec_sensors_capture(int irq, void *p);
> > int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
>
