Re: [RFC][PATCH] ACPI: battery: add power_{now, avg} properties to power_class

["Rafael J. Wysocki" <rjw@sisk.pl>]

Hi,

On Monday, 15 of December 2008, Alexey Starikovskiy wrote:
> ACPI has smart batteries, which work in units of energy and measure
> rate of (dis)charge as power, thus it is not appropriate to export it
> as a current_now.
> 
> Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
> ---
> 
>  drivers/acpi/battery.c             |    3 ++-
>  drivers/acpi/sbs.c                 |    6 ++++--
>  drivers/power/power_supply_sysfs.c |    2 ++
>  include/linux/power_supply.h       |    2 ++
>  4 files changed, 10 insertions(+), 3 deletions(-)
> 
> 
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index 1423b0c..88f1fb5 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -173,6 +173,7 @@ static int acpi_battery_get_property(struct power_supply *psy,
>  		val->intval = battery->voltage_now * 1000;
>  		break;
>  	case POWER_SUPPLY_PROP_CURRENT_NOW:
> +	case POWER_SUPPLY_PROP_POWER_NOW:
>  		val->intval = battery->current_now * 1000;
>  		break;
>  	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> @@ -223,7 +224,7 @@ static enum power_supply_property energy_battery_props[] = {
>  	POWER_SUPPLY_PROP_TECHNOLOGY,
>  	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
>  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
> -	POWER_SUPPLY_PROP_CURRENT_NOW,
> +	POWER_SUPPLY_PROP_POWER_NOW,
>  	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
>  	POWER_SUPPLY_PROP_ENERGY_FULL,
>  	POWER_SUPPLY_PROP_ENERGY_NOW,
> diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
> index 6050ce4..994c04e 100644
> --- a/drivers/acpi/sbs.c
> +++ b/drivers/acpi/sbs.c
> @@ -224,10 +224,12 @@ static int acpi_sbs_battery_get_property(struct power_supply *psy,
>  				acpi_battery_vscale(battery) * 1000;
>  		break;
>  	case POWER_SUPPLY_PROP_CURRENT_NOW:
> +	case POWER_SUPPLY_PROP_POWER_NOW:
>  		val->intval = abs(battery->current_now) *
>  				acpi_battery_ipscale(battery) * 1000;

Please introduce another field called 'battery->power_now' for this purpose.
Otherwise, confusion is guaranteed to ensue.

>  		break;
>  	case POWER_SUPPLY_PROP_CURRENT_AVG:
> +	case POWER_SUPPLY_PROP_POWER_AVG:
>  		val->intval = abs(battery->current_avg) *
>  				acpi_battery_ipscale(battery) * 1000;

Same here.

Also, as per our IRC conversation, I'd like 'current_now' to be reported even
if energy units are used, at least for some time, to give a chance to the user
land to switch to 'power_now' and 'power_avg' without pain.

You can put information about that into
Documentation/feature-removal-schedule.txt and say that after 2.6.29
'current_now' will no longer be reported when energy units are used.

Thanks,
Rafael