Re: [External] [PATCH 4/4] platform/x86: thinkpad_acpi: support inhibit-charge

From: Mark Pearson
Date: Wed Nov 17 2021 - 10:10:04 EST


Hi Thomas

On 2021-11-16 18:44, Thomas Weißschuh wrote:
> Hi Mark,
>
> On 2021-11-16 15:52-0500, Mark Pearson wrote:
>> On 2021-11-13 05:42, Thomas Weißschuh wrote:
>>> This adds support for the inhibit-charge charge_behaviour through the
>>> embedded controller of ThinkPads.
>>>
>>> Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
>>>
>>> ---
>>>
>>> This patch is based on https://lore.kernel.org/platform-driver-x86/d2808930-5840-6ffb-3a59-d235cdb1fe16@xxxxxxxxx/ ---
>>> drivers/platform/x86/thinkpad_acpi.c | 55 +++++++++++++++++++++++++++-
>>> 1 file changed, 53 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
>>> index e8c98e9aff71..7cd6475240b2 100644
>>> --- a/drivers/platform/x86/thinkpad_acpi.c
>>> +++ b/drivers/platform/x86/thinkpad_acpi.c
>>> @@ -9321,6 +9321,8 @@ static struct ibm_struct mute_led_driver_data = {
>>> #define SET_STOP "BCSS"
>>> #define GET_DISCHARGE "BDSG"
>>> #define SET_DISCHARGE "BDSS"
>>> +#define GET_INHIBIT "PSSG"
>>> +#define SET_INHIBIT "BICS"
>>>
>>> enum {
>>> BAT_ANY = 0,
>>> @@ -9338,6 +9340,7 @@ enum {
>>> THRESHOLD_START,
>>> THRESHOLD_STOP,
>>> FORCE_DISCHARGE,
>>> + INHIBIT_CHARGE,
>>> };
>>>
>>> struct tpacpi_battery_data {
>>> @@ -9409,6 +9412,13 @@ static int tpacpi_battery_get(int what, int battery, int *ret)
>>> /* The force discharge status is in bit 0 */
>>> *ret = *ret & 0x01;
>>> return 0;
>>> + case INHIBIT_CHARGE:
>>> + /* This is actually reading peak shift state, like tpacpi-bat does */
>>> + if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_INHIBIT, ret, battery))
>>> + return -ENODEV;
>>> + /* The inhibit charge status is in bit 0 */
>>> + *ret = *ret & 0x01;
>>> + return 0;
>>> default:
>>> pr_crit("wrong parameter: %d", what);
>>> return -EINVAL;
>>> @@ -9447,6 +9457,22 @@ static int tpacpi_battery_set(int what, int battery, int value)
>>> return -ENODEV;
>>> }
>>> return 0;
>>> + case INHIBIT_CHARGE:
>>> + /* When setting inhibit charge, we set a default value of
>>> + * always breaking on AC detach and the effective time is set to
>>> + * be permanent.
>>> + * The battery ID is in bits 4-5, 2 bits,
>>> + * the effective time is in bits 8-23, 2 bytes.
>>> + * A time of FFFF indicates forever.
>>> + */
>>> + param = value;
>>> + param |= battery << 4;
>>> + param |= 0xFFFF << 8;
>>> + if (ACPI_FAILURE(tpacpi_battery_acpi_eval(SET_INHIBIT, &ret, param))) {
>>> + pr_err("failed to set inhibit charge on %d", battery);
>>> + return -ENODEV;
>>> + }
>>> + return 0;
>>> default:
>>> pr_crit("wrong parameter: %d", what);
>>> return -EINVAL;
>>> @@ -9467,6 +9493,8 @@ static int tpacpi_battery_probe(int battery)
>>> * 4) Check for support
>>> * 5) Get the current force discharge status
>>> * 6) Check for support
>>> + * 7) Get the current inhibit charge status
>>> + * 8) Check for support
>>> */
>>> if (acpi_has_method(hkey_handle, GET_START)) {
>>> if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_START, &ret, battery)) {
>>> @@ -9513,6 +9541,16 @@ static int tpacpi_battery_probe(int battery)
>>> battery_info.batteries[battery].charge_behaviours |=
>>> BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE);
>>> }
>>> + if (acpi_has_method(hkey_handle, GET_INHIBIT)) {
>>> + if (ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_INHIBIT, &ret, battery))) {
>>> + pr_err("Error probing battery inhibit charge; %d\n", battery);
>>> + return -ENODEV;
>>> + }
>>> + /* Support is marked in bit 5 */
>>> + if (ret & BIT(5))
>>> + battery_info.batteries[battery].charge_behaviours |=
>>> + BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE);
>>> + }
>>>
>>> battery_info.batteries[battery].charge_behaviours |=
>>> BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO);
>>> @@ -9673,6 +9711,11 @@ static ssize_t charge_behaviour_show(struct device *dev,
>>> return -ENODEV;
>>> if (ret)
>>> active = POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE;
>>> + } else if (available & BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE)) {
>>> + if (tpacpi_battery_get(INHIBIT_CHARGE, battery, &ret))
>>> + return -ENODEV;
>>> + if (ret)
>>> + active = POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE;
>>> }
>>>
>>> return power_supply_charge_behaviour_show(dev, available, active, buf);
>>> @@ -9710,12 +9753,20 @@ static ssize_t charge_behaviour_store(struct device *dev,
>>> switch (selected) {
>>> case POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO:
>>> ret = tpacpi_battery_set(FORCE_DISCHARGE, battery, 0);
>>> - if (ret < 0)
>>> + ret = tpacpi_battery_set(INHIBIT_CHARGE, battery, 0) || ret;
>>> + if (ret)
>>> return ret;
>>> break;
>>> case POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE:
>>> ret = tpacpi_battery_set(FORCE_DISCHARGE, battery, 1);
>>> - if (ret < 0)
>>> + ret = tpacpi_battery_set(INHIBIT_CHARGE, battery, 0) || ret;
>>> + if (ret)
>>> + return ret;
>>> + break;
>>> + case POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE:
>>> + ret = tpacpi_battery_set(FORCE_DISCHARGE, battery, 0);
>>> + ret = tpacpi_battery_set(INHIBIT_CHARGE, battery, 1) || ret;
>>> + if (ret)
>>> return ret;
>>> break;
>>> default:
>>>
>>
>> I can confirm the bit fields are correct for these calls (as for the
>> previous patch)
>
> Thanks!
>
> Could you doublecheck the behavior for multiple batteries to maybe find a
> reason why BAT1 is not inhibited as reported by Thomas Koch [0]?
>
>> Couple of things to note, based on feedback previously from the FW team
>> that I found when digging thru my battery related emails.
>>
>> "Lenovo doesn't officially support the use of these calls - they're
>> intended for internal use" (at this point in time - there is some
>> discussion about battery recalibration support but I don't have details
>> I can share there yet).
>>
>> The FW team also noted that:
>>
>> "Actual battery charging/discharging behaviors are managed by ECFW. So
>> the request of BDSS/BICS method may be rejected by ECFW for the current
>> battery mode/status. You have to check if the request of the method is
>> actually applied or not"
>>
>> So for the calls above (and for the BDSS calls in the previous patch) it
>> would be good to do a read back of the setting to ensure it has
>> completed successfully.
>
> I'll add that for v2.
>
>> Hope that helps
>
> It does, thanks!
>
> Thomas
>
> [0] https://lore.kernel.org/platform-driver-x86/9cebba85-f399-a7aa-91f7-237852338dc5@xxxxxxx/>>
I got confirmation that:

<quote>
BDSS have to be used with specific battery. Please use with Primary(=1b)
or Secondary(2b) as Battery ID (Bit9-8)

Bit 9-8: Battery ID
= 0: Any battery
= 1: Primary battery
= 2: Secondary battery
</quote>

It seems you can't use BDSS with all batteries.
I'll confirm on BICS what the limitations are, they didn't update on
that piece yet I'm afraid. Unfortunately I don't think I have any
systems with two batteries to test myself.

Mark