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.
> +
> + /*
> + * 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,
