linux-kernel - Re: [PATCH] HID: logitech-hidpp: BatteryVoltage: only read chargeStatus if extPower is active

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Message-ID: <aaca852e-cb31-2690-7f90-819ed673bacb@pedrovanzella.com>
Date:   Mon, 20 Jan 2020 10:43:36 -0300
From:   Pedro Vanzella <pedro@...rovanzella.com>
To:     Filipe Laíns <lains@...hlinux.org>,
        Jiri Kosina <jikos@...nel.org>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        Henrik Rydberg <rydberg@...math.org>,
        linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] HID: logitech-hidpp: BatteryVoltage: only read
 chargeStatus if extPower is active

On 1/11/20 4:24 PM, Filipe Laíns wrote:
> In the HID++ 2.0 function getBatteryInfo() from the BatteryVoltage
> (0x1001) feature, chargeStatus is only valid if extPower is active.
> 
> Previously we were ignoring extPower, which resulted in wrong values.

Nice catch. Sorry for missing that the first time around.

> 
> Example:
>      With an unplugged mouse
> 
>      $ cat /sys/class/power_supply/hidpp_battery_0/status
>      Charging

Tested and it works as expected now.

> 
> This patch makes fixes that, it also renames charge_sts to flags as
> charge_sts can be confused with chargeStatus from the spec.
> 
> Spec:
> +--------+-------------------------------------------------------------------------+
> |  byte  |                                    2                                    |
> +--------+--------------+------------+------------+----------+----------+----------+
> |   bit  |     0..2     |      3     |      4     |     5    |     6    |     7    |
> +--------+--------------+------------+------------+----------+----------+----------+
> | buffer | chargeStatus | fastCharge | slowCharge | critical | (unused) | extPower |
> +--------+--------------+------------+------------+----------+----------+----------+
> Table 1 - battery voltage (0x1001), getBatteryInfo() (ASE 0), 3rd byte
> 
> +-------+--------------------------------------+
> | value |                meaning               |
> +-------+--------------------------------------+
> |   0   | Charging                             |
> +-------+--------------------------------------+
> |   1   | End of charge (100% charged)         |
> +-------+--------------------------------------+
> |   2   | Charge stopped (any "normal" reason) |
> +-------+--------------------------------------+
> |   7   | Hardware error                       |
> +-------+--------------------------------------+
> Table 2 - chargeStatus value
> 
> Signed-off-by: Filipe Laíns <lains@...hlinux.org>
> ---
>   drivers/hid/hid-logitech-hidpp.c | 43 ++++++++++++++++----------------
>   1 file changed, 21 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
> index bb063e7d48df..39a5ee0aaab0 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -1256,36 +1256,35 @@ static int hidpp20_battery_map_status_voltage(u8 data[3], int *voltage,
>   {
>   	int status;
>   
> -	long charge_sts = (long)data[2];
> +	long flags = (long) data[2];
>   
> -	*level = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
> -	switch (data[2] & 0xe0) {
> -	case 0x00:
> -		status = POWER_SUPPLY_STATUS_CHARGING;
> -		break;
> -	case 0x20:
> -		status = POWER_SUPPLY_STATUS_FULL;
> -		*level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
> -		break;
> -	case 0x40:
> +	if (flags & 0x80)
> +		switch (flags & 0x07) {
> +		case 0:
> +			status = POWER_SUPPLY_STATUS_CHARGING;
> +			break;
> +		case 1:
> +			status = POWER_SUPPLY_STATUS_FULL;
> +			*level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
> +			break;
> +		case 2:
> +			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +			break;
> +		default:
> +			status = POWER_SUPPLY_STATUS_UNKNOWN;
> +			break;
> +		}
> +	else
>   		status = POWER_SUPPLY_STATUS_DISCHARGING;
> -		break;
> -	case 0xe0:
> -		status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> -		break;
> -	default:
> -		status = POWER_SUPPLY_STATUS_UNKNOWN;
> -	}
>   
>   	*charge_type = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
> -	if (test_bit(3, &charge_sts)) {
> +	if (test_bit(3, &flags)) {
>   		*charge_type = POWER_SUPPLY_CHARGE_TYPE_FAST;
>   	}
> -	if (test_bit(4, &charge_sts)) {
> +	if (test_bit(4, &flags)) {
>   		*charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
>   	}
> -
> -	if (test_bit(5, &charge_sts)) {
> +	if (test_bit(5, &flags)) {
>   		*level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
>   	}
>   
> 

Tested-by: Pedro Vanzella <pedro@...rovanzella.com>
Reviewed-by: Pedro Vanzella <pedro@...rovanzella.com>