Re: [PATCH v2 2/4] drivers: devfreq: events: extend events by type of counted data

[Lukasz Luba]

Hi Chanwoo,

please ignore this patch there is a comment below.
It wrongly sets the default value.

On 4/18/19 3:38 PM, Lukasz Luba wrote:
> This patch adds posibility to choose what type of data should be counted
> by the PPMU counter. Now the type comes from DT where the event has been
> defined. When there is no 'event-data-type' the default value is used,
> which is 'read data in bytes'.
> It is needed when you want to know not only read+write data bytes but
> i.e. only write data in byte, or number of read requests, etc.
> 
> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
> ---
>   drivers/devfreq/event/exynos-ppmu.c | 61 +++++++++++++++++++++++++------------
>   include/linux/devfreq-event.h       |  6 ++++
>   2 files changed, 48 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
> index c61de0b..9f12201 100644
> --- a/drivers/devfreq/event/exynos-ppmu.c
> +++ b/drivers/devfreq/event/exynos-ppmu.c
> @@ -154,9 +154,9 @@ static int exynos_ppmu_set_event(struct devfreq_event_dev *edev)
>   	if (ret < 0)
>   		return ret;
>   
> -	/* Set the event of Read/Write data count  */
> +	/* Set the event of proper data type monitoring */
>   	ret = regmap_write(info->regmap, PPMU_BEVTxSEL(id),
> -				PPMU_RO_DATA_CNT | PPMU_WO_DATA_CNT);
> +			   edev->desc->data_type);
>   	if (ret < 0)
>   		return ret;
>   
> @@ -368,23 +368,11 @@ static int exynos_ppmu_v2_set_event(struct devfreq_event_dev *edev)
>   	if (ret < 0)
>   		return ret;
>   
> -	/* Set the event of Read/Write data count  */
> -	switch (id) {
> -	case PPMU_PMNCNT0:
> -	case PPMU_PMNCNT1:
> -	case PPMU_PMNCNT2:
> -		ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
> -				PPMU_V2_RO_DATA_CNT | PPMU_V2_WO_DATA_CNT);
> -		if (ret < 0)
> -			return ret;
> -		break;
> -	case PPMU_PMNCNT3:
> -		ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
> -				PPMU_V2_EVT3_RW_DATA_CNT);
> -		if (ret < 0)
> -			return ret;
> -		break;
> -	}
> +	/* Set the event of proper data type monitoring */
> +	ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
> +			   edev->desc->data_type);
> +	if (ret < 0)
> +		return ret;
>   
>   	/* Reset cycle counter/performance counter and enable PPMU */
>   	ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
> @@ -508,6 +496,7 @@ static int of_get_devfreq_events(struct device_node *np,
>   	struct device *dev = info->dev;
>   	struct device_node *events_np, *node;
>   	int i, j, count;
> +	int ret;
>   
>   	events_np = of_get_child_by_name(np, "events");
>   	if (!events_np) {
> @@ -544,6 +533,40 @@ static int of_get_devfreq_events(struct device_node *np,
>   		desc[j].driver_data = info;
>   
>   		of_property_read_string(node, "event-name", &desc[j].name);
> +		ret = of_property_read_u32(node, "event-data-type",
> +					   &desc[j].data_type);
> +		if (!ret) {
It should be: if (ret)
then it means we do not have a value in DT and we are using
our defaults taking into account the right register type.

I am going to send v3 with this fix.

Regards,
Lukasz
> +			/* Set the event of proper data type counting.
> +			 * Check if the data type has been defined in DT,
> +			 * use default if not.
> +			 */
> +			if (of_device_is_compatible(np,
> +					"samsung,exynos-ppmu-v2")) {
> +				struct devfreq_event_dev edev;
> +				int id;
> +				/* Not all registers take the same value for
> +				 * read+write data count.
> +				 */
> +				edev.desc = &desc[j];
> +				id = exynos_ppmu_find_ppmu_id(&edev);
> +
> +				switch (id) {
> +				case PPMU_PMNCNT0:
> +				case PPMU_PMNCNT1:
> +				case PPMU_PMNCNT2:
> +					desc[j].data_type = PPMU_V2_RO_DATA_CNT
> +						| PPMU_V2_WO_DATA_CNT;
> +					break;
> +				case PPMU_PMNCNT3:
> +					desc[j].data_type =
> +						PPMU_V2_EVT3_RW_DATA_CNT;
> +					break;
> +				}
> +			} else {
> +				desc[j].data_type = PPMU_RO_DATA_CNT |
> +					PPMU_WO_DATA_CNT;
> +			}
> +		}
>   
>   		j++;
>   	}
> diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
> index 4db00b0..cc160b1 100644
> --- a/include/linux/devfreq-event.h
> +++ b/include/linux/devfreq-event.h
> @@ -81,14 +81,20 @@ struct devfreq_event_ops {
>    * struct devfreq_event_desc - the descriptor of devfreq-event device
>    *
>    * @name	: the name of devfreq-event device.
> + * @data_type	: the data type which is going to be counted in the register.
>    * @driver_data	: the private data for devfreq-event driver.
>    * @ops		: the operation to control devfreq-event device.
>    *
>    * Each devfreq-event device is described with a this structure.
>    * This structure contains the various data for devfreq-event device.
> + * The data_type describes what is going to be counted in the register.
> + * It might choose to count e.g. read requests, write data in bytes, etc.
> + * The full supported list of types is present in specyfic header in:
> + * include/dt-bindings/pmu/.
>    */
>   struct devfreq_event_desc {
>   	const char *name;
> +	u32 data_type;
>   	void *driver_data;
>   
>   	const struct devfreq_event_ops *ops;
>