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Message-ID: <f5b7c3fe-dfcf-da4f-b0a8-2ed256b95d47@lenovo.com>
Date: Tue, 16 Nov 2021 15:35:17 -0500
From: Mark Pearson <markpearson@...ovo.com>
To: Thomas Weißschuh <linux@...ssschuh.net>,
<linux-pm@...r.kernel.org>, Sebastian Reichel <sre@...nel.org>,
<ibm-acpi-devel@...ts.sourceforge.net>,
<platform-driver-x86@...r.kernel.org>,
Mark Gross <markgross@...nel.org>,
Hans de Goede <hdegoede@...hat.com>,
Henrique de Moraes Holschuh <hmh@....eng.br>
CC: <linux-kernel@...r.kernel.org>, <linrunner@....net>,
<bberg@...hat.com>, <hadess@...ess.net>,
<nicolopiazzalunga@...il.com>, <njoshi1@...ovo.com>,
<smclt30p@...il.com>
Subject: Re: [External] [PATCH 3/4] platform/x86: thinkpad_acpi: support
force-discharge
Hi Thomas,
On 2021-11-13 05:42, Thomas Weißschuh wrote:
> This adds support for the force-discharge charge_behaviour through the
> embedded controller of ThinkPads.
>
> Signed-off-by: Thomas Weißschuh <linux@...ssschuh.net>
>
> ---
>
> This patch is based on https://lore.kernel.org/platform-driver-x86/c2504700-06e9-e7d8-80f7-de90b0b6dfb5@gmail.com/>> ---
> drivers/platform/x86/thinkpad_acpi.c | 103 +++++++++++++++++++++++++--
> 1 file changed, 99 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index 9c632df734bb..e8c98e9aff71 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -9319,6 +9319,8 @@ static struct ibm_struct mute_led_driver_data = {
> #define SET_START "BCCS"
> #define GET_STOP "BCSG"
> #define SET_STOP "BCSS"
> +#define GET_DISCHARGE "BDSG"
> +#define SET_DISCHARGE "BDSS"
>
> enum {
> BAT_ANY = 0,
> @@ -9335,6 +9337,7 @@ enum {
> /* This is used in the get/set helpers */
> THRESHOLD_START,
> THRESHOLD_STOP,
> + FORCE_DISCHARGE,
> };
>
> struct tpacpi_battery_data {
> @@ -9342,6 +9345,7 @@ struct tpacpi_battery_data {
> int start_support;
> int charge_stop;
> int stop_support;
> + unsigned int charge_behaviours;
> };
>
> struct tpacpi_battery_driver_data {
> @@ -9399,6 +9403,12 @@ static int tpacpi_battery_get(int what, int battery, int *ret)
> if (*ret == 0)
> *ret = 100;
> return 0;
> + case FORCE_DISCHARGE:
> + if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_DISCHARGE, ret, battery))
> + return -ENODEV;
> + /* The force discharge status is in bit 0 */
> + *ret = *ret & 0x01;
> + return 0;
> default:
> pr_crit("wrong parameter: %d", what);
> return -EINVAL;
> @@ -9427,6 +9437,16 @@ static int tpacpi_battery_set(int what, int battery, int value)
> return -ENODEV;
> }
> return 0;
> + case FORCE_DISCHARGE:
> + /* Force discharge is in bit 0,
> + * break on AC attach is in bit 1 (won't work on some ThinkPads),
> + * battery ID is in bits 8-9, 2 bits.
> + */
> + if (ACPI_FAILURE(tpacpi_battery_acpi_eval(SET_DISCHARGE, &ret, param))) {
> + pr_err("failed to set force dischrage on %d", battery);
> + return -ENODEV;
> + }
> + return 0;
> default:
> pr_crit("wrong parameter: %d", what);
> return -EINVAL;
> @@ -9445,6 +9465,8 @@ static int tpacpi_battery_probe(int battery)
> * 2) Check for support
> * 3) Get the current stop threshold
> * 4) Check for support
> + * 5) Get the current force discharge status
> + * 6) Check for support
> */
> if (acpi_has_method(hkey_handle, GET_START)) {
> if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_START, &ret, battery)) {
> @@ -9481,10 +9503,25 @@ static int tpacpi_battery_probe(int battery)
> return -ENODEV;
> }
> }
> - pr_info("battery %d registered (start %d, stop %d)",
> - battery,
> - battery_info.batteries[battery].charge_start,
> - battery_info.batteries[battery].charge_stop);
> + if (acpi_has_method(hkey_handle, GET_DISCHARGE)) {
> + if (ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_DISCHARGE, &ret, battery))) {
> + pr_err("Error probing battery discharge; %d\n", battery);
> + return -ENODEV;
> + }
> + /* Support is marked in bit 8 */
> + if (ret & BIT(8))
> + battery_info.batteries[battery].charge_behaviours |=
> + BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE);
> + }
> +
> + battery_info.batteries[battery].charge_behaviours |=
> + BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO);
> +
> + pr_info("battery %d registered (start %d, stop %d, behaviours: 0x%x)\n",
> + battery,
> + battery_info.batteries[battery].charge_start,
> + battery_info.batteries[battery].charge_stop,
> + battery_info.batteries[battery].charge_behaviours);
>
> return 0;
> }
> @@ -9619,6 +9656,28 @@ static ssize_t charge_control_end_threshold_show(struct device *device,
> return tpacpi_battery_show(THRESHOLD_STOP, device, buf);
> }
>
> +static ssize_t charge_behaviour_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + enum power_supply_charge_behaviour active = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
> + struct power_supply *supply = to_power_supply(dev);
> + unsigned int available;
> + int ret, battery;
> +
> + battery = tpacpi_battery_get_id(supply->desc->name);
> + available = battery_info.batteries[battery].charge_behaviours;
> +
> + if (available & BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE)) {
> + if (tpacpi_battery_get(FORCE_DISCHARGE, battery, &ret))
> + return -ENODEV;
> + if (ret)
> + active = POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE;
> + }
> +
> + return power_supply_charge_behaviour_show(dev, available, active, buf);
> +}
> +
> static ssize_t charge_control_start_threshold_store(struct device *dev,
> struct device_attribute *attr,
> const char *buf, size_t count)
> @@ -9633,8 +9692,43 @@ static ssize_t charge_control_end_threshold_store(struct device *dev,
> return tpacpi_battery_store(THRESHOLD_STOP, dev, buf, count);
> }
>
> +static ssize_t charge_behaviour_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct power_supply *supply = to_power_supply(dev);
> + int selected, battery, ret;
> + unsigned int available;
> +
> + battery = tpacpi_battery_get_id(supply->desc->name);
> + available = battery_info.batteries[battery].charge_behaviours;
> + selected = power_supply_charge_behaviour_parse(available, buf);
> +
> + if (selected < 0)
> + return selected;
> +
> + switch (selected) {
> + case POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO:
> + ret = tpacpi_battery_set(FORCE_DISCHARGE, battery, 0);
> + if (ret < 0)
> + return ret;
> + break;
> + case POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE:
> + ret = tpacpi_battery_set(FORCE_DISCHARGE, battery, 1);
> + if (ret < 0)
> + return ret;
> + break;
> + default:
> + dev_err(dev, "Unexpected charge behaviour: %d\n", selected);
> + return -EINVAL;
> + }
> +
> + return count;
> +}
> +
> static DEVICE_ATTR_RW(charge_control_start_threshold);
> static DEVICE_ATTR_RW(charge_control_end_threshold);
> +static DEVICE_ATTR_RW(charge_behaviour);
> static struct device_attribute dev_attr_charge_start_threshold = __ATTR(
> charge_start_threshold,
> 0644,
> @@ -9653,6 +9747,7 @@ static struct attribute *tpacpi_battery_attrs[] = {
> &dev_attr_charge_control_end_threshold.attr,
> &dev_attr_charge_start_threshold.attr,
> &dev_attr_charge_stop_threshold.attr,
> + &dev_attr_charge_behaviour.attr,
> NULL,
> };
>
>
Sorry for the slow review - been busy this week. Thank you for
implementing this - it's great to be getting this into the kernel and
it's something we have had on our todo list for a little while now.
I can confirm the BDSG and BDSS APIs are correct along with the bit
field defines you have used. Not sure if that's helpful but as I have
access to some internal documents I figured I'd check :)
I'll note that bit 10 in BDSG should flag if the 'enable breaking by AC
detaching' feature is supported. You're not using it so I don't think
that's important - but figured I'd mention it because of the comment
that not all thinkpads support it.
Mark
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