Re: [PATCH v2 1/2] HID: hid-sensor-hub: Enhance get feature report API

[Jonathan Cameron <jic23@kernel.org>]

On 17/01/15 00:39, Srinivas Pandruvada wrote:
> Some hid sensor feature report can contain more than one reports.
> This API can now support receiving multiple values from the feature
> report.
> Also update the parameters in the users of this API.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Oops, commented on old version.
Acked-by: Jonathan Cameron <jic23@kernel.org>
> ---
>  drivers/hid/hid-sensor-hub.c                           | 15 +++++++++++++--
>  drivers/iio/common/hid-sensors/hid-sensor-attributes.c | 13 +++++++------
>  drivers/iio/common/hid-sensors/hid-sensor-trigger.c    |  4 ++--
>  include/linux/hid-sensor-hub.h                         |  8 +++++---
>  4 files changed, 27 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
> index e54ce10..4d22bd4 100644
> --- a/drivers/hid/hid-sensor-hub.c
> +++ b/drivers/hid/hid-sensor-hub.c
> @@ -232,10 +232,11 @@ done_proc:
>  EXPORT_SYMBOL_GPL(sensor_hub_set_feature);
>  
>  int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
> -				u32 field_index, s32 *value)
> +			   u32 field_index, int buffer_size, void *buffer)
>  {
>  	struct hid_report *report;
>  	struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
> +	int report_size;
>  	int ret = 0;
>  
>  	mutex_lock(&data->mutex);
> @@ -247,7 +248,17 @@ int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
>  	}
>  	hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
>  	hid_hw_wait(hsdev->hdev);
> -	*value = report->field[field_index]->value[0];
> +
> +	/* calculate number of bytes required to read this field */
> +	report_size = DIV_ROUND_UP(report->field[field_index]->report_size,
> +				   8) *
> +				   report->field[field_index]->report_count;
> +	if (!report_size) {
> +		ret = -EINVAL;
> +		goto done_proc;
> +	}
> +	ret = min(report_size, buffer_size);
> +	memcpy(buffer, report->field[field_index]->value, ret);
>  
>  done_proc:
>  	mutex_unlock(&data->mutex);
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> index 25b01e1..e1435e9 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> @@ -153,8 +153,8 @@ s32 hid_sensor_read_poll_value(struct hid_sensor_common *st)
>  	int ret;
>  
>  	ret = sensor_hub_get_feature(st->hsdev,
> -		st->poll.report_id,
> -		st->poll.index, &value);
> +				     st->poll.report_id,
> +				     st->poll.index, sizeof(value), &value);
>  
>  	if (ret < 0 || value < 0) {
>  		return -EINVAL;
> @@ -174,8 +174,8 @@ int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
>  	int ret;
>  
>  	ret = sensor_hub_get_feature(st->hsdev,
> -		st->poll.report_id,
> -		st->poll.index, &value);
> +				     st->poll.report_id,
> +				     st->poll.index, sizeof(value), &value);
>  	if (ret < 0 || value < 0) {
>  		*val1 = *val2 = 0;
>  		return -EINVAL;
> @@ -229,8 +229,9 @@ int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
>  	int ret;
>  
>  	ret = sensor_hub_get_feature(st->hsdev,
> -		st->sensitivity.report_id,
> -		st->sensitivity.index, &value);
> +				     st->sensitivity.report_id,
> +				     st->sensitivity.index, sizeof(value),
> +				     &value);
>  	if (ret < 0 || value < 0) {
>  		*val1 = *val2 = 0;
>  		return -EINVAL;
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> index 92068cd..ef0c495 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
> @@ -76,8 +76,8 @@ int hid_sensor_power_state(struct hid_sensor_common *st, bool state)
>  	}
>  
>  	sensor_hub_get_feature(st->hsdev, st->power_state.report_id,
> -					st->power_state.index,
> -					&state_val);
> +			       st->power_state.index,
> +			       sizeof(state_val), &state_val);
>  	return 0;
>  }
>  EXPORT_SYMBOL(hid_sensor_power_state);
> diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
> index 4173a8f..dfdf6ef 100644
> --- a/include/linux/hid-sensor-hub.h
> +++ b/include/linux/hid-sensor-hub.h
> @@ -179,13 +179,15 @@ int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
>  * @hsdev:	Hub device instance.
>  * @report_id:	Report id to look for
>  * @field_index:	Field index inside a report
> -* @value:	Place holder for return value
> +* @buffer_size:	size of the buffer
> +* @buffer:	buffer to copy output
>  *
>  * Used to get a field in feature report. For example this can get polling
> -* interval, sensitivity, activate/deactivate state.
> +* interval, sensitivity, activate/deactivate state. On success it returns
> +* number of bytes copied to buffer. On failure, it returns value < 0.
>  */
>  int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
> -			u32 field_index, s32 *value);
> +			   u32 field_index, int buffer_size, void *buffer);
>  
>  /* hid-sensor-attributes */
>  
>