Re: [PATCH] iio: hid-sensor-press: Add timestamp channel

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 31 Jul 2021 11:25:56 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> Each sample has a timestamp field with this change. This timestamp may
> be from the sensor hub when present or local kernel timestamp. The
> unit of timestamp is nanosecond.
> 
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Applied to the togreg branch of iio.git and pushed out as testing to
let 0-day see what it can find.

Thanks,

Jonathan

> ---
>  drivers/iio/pressure/hid-sensor-press.c | 40 +++++++++++++++----------
>  1 file changed, 24 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/pressure/hid-sensor-press.c b/drivers/iio/pressure/hid-sensor-press.c
> index c416d261e3e3..b365483bd09e 100644
> --- a/drivers/iio/pressure/hid-sensor-press.c
> +++ b/drivers/iio/pressure/hid-sensor-press.c
> @@ -16,17 +16,24 @@
>  #include <linux/iio/buffer.h>
>  #include "../common/hid-sensors/hid-sensor-trigger.h"
>  
> -#define CHANNEL_SCAN_INDEX_PRESSURE 0
> +enum {
> +	CHANNEL_SCAN_INDEX_PRESSURE,
> +	CHANNEL_SCAN_INDEX_TIMESTAMP,
> +};
>  
>  struct press_state {
>  	struct hid_sensor_hub_callbacks callbacks;
>  	struct hid_sensor_common common_attributes;
>  	struct hid_sensor_hub_attribute_info press_attr;
> -	u32 press_data;
> +	struct {
> +		u32 press_data;
> +		u64 timestamp __aligned(8);
> +	} scan;
>  	int scale_pre_decml;
>  	int scale_post_decml;
>  	int scale_precision;
>  	int value_offset;
> +	s64 timestamp;
>  };
>  
>  static const u32 press_sensitivity_addresses[] = {
> @@ -44,7 +51,9 @@ static const struct iio_chan_spec press_channels[] = {
>  		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>  		BIT(IIO_CHAN_INFO_HYSTERESIS),
>  		.scan_index = CHANNEL_SCAN_INDEX_PRESSURE,
> -	}
> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)
> +
>  };
>  
>  /* Adjust channel real bits based on report descriptor */
> @@ -157,14 +166,6 @@ static const struct iio_info press_info = {
>  	.write_raw = &press_write_raw,
>  };
>  
> -/* Function to push data to buffer */
> -static void hid_sensor_push_data(struct iio_dev *indio_dev, const void *data,
> -					int len)
> -{
> -	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
> -	iio_push_to_buffers(indio_dev, data);
> -}
> -
>  /* Callback handler to send event after all samples are received and captured */
>  static int press_proc_event(struct hid_sensor_hub_device *hsdev,
>  				unsigned usage_id,
> @@ -174,10 +175,13 @@ static int press_proc_event(struct hid_sensor_hub_device *hsdev,
>  	struct press_state *press_state = iio_priv(indio_dev);
>  
>  	dev_dbg(&indio_dev->dev, "press_proc_event\n");
> -	if (atomic_read(&press_state->common_attributes.data_ready))
> -		hid_sensor_push_data(indio_dev,
> -				&press_state->press_data,
> -				sizeof(press_state->press_data));
> +	if (atomic_read(&press_state->common_attributes.data_ready)) {
> +		if (!press_state->timestamp)
> +			press_state->timestamp = iio_get_time_ns(indio_dev);
> +
> +		iio_push_to_buffers_with_timestamp(
> +			indio_dev, &press_state->scan, press_state->timestamp);
> +	}
>  
>  	return 0;
>  }
> @@ -194,9 +198,13 @@ static int press_capture_sample(struct hid_sensor_hub_device *hsdev,
>  
>  	switch (usage_id) {
>  	case HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE:
> -		press_state->press_data = *(u32 *)raw_data;
> +		press_state->scan.press_data = *(u32 *)raw_data;
>  		ret = 0;
>  		break;
> +	case HID_USAGE_SENSOR_TIME_TIMESTAMP:
> +		press_state->timestamp = hid_sensor_convert_timestamp(
> +			&press_state->common_attributes, *(s64 *)raw_data);
> +		break;
>  	default:
>  		break;
>  	}