platform/x86: thinkpad_acpi: support force-discharge

This adds support for the force-discharge charge_behaviour through the
embedded controller of ThinkPads.

Co-developed-by: Thomas Koch <linrunner@gmx.net>
Signed-off-by: Thomas Koch <linrunner@gmx.net>
Co-developed-by: Nicolò Piazzalunga <nicolopiazzalunga@gmail.com>
Signed-off-by: Nicolò Piazzalunga <nicolopiazzalunga@gmail.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20211123232704.25394-4-linux@weissschuh.net
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 38996e6..4dea533 100644 (file)
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -9214,6 +9214,8 @@ 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,
@@ -9230,6 +9232,7 @@ enum {
        /* This is used in the get/set helpers */
        THRESHOLD_START,
        THRESHOLD_STOP,
+       FORCE_DISCHARGE,
 };
 
 struct tpacpi_battery_data {
@@ -9237,6 +9240,7 @@ struct tpacpi_battery_data {
        int start_support;
        int charge_stop;
        int stop_support;
+       unsigned int charge_behaviours;
 };
 
 struct tpacpi_battery_driver_data {
@@ -9294,6 +9298,12 @@ 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;
@@ -9322,12 +9332,49 @@ 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 discharge on %d", battery);
+                       return -ENODEV;
+               }
+               return 0;
        default:
                pr_crit("wrong parameter: %d", what);
                return -EINVAL;
        }
 }
 
+static int tpacpi_battery_set_validate(int what, int battery, int value)
+{
+       int ret, v;
+
+       ret = tpacpi_battery_set(what, battery, value);
+       if (ret < 0)
+               return ret;
+
+       ret = tpacpi_battery_get(what, battery, &v);
+       if (ret < 0)
+               return ret;
+
+       if (v == value)
+               return 0;
+
+       msleep(500);
+
+       ret = tpacpi_battery_get(what, battery, &v);
+       if (ret < 0)
+               return ret;
+
+       if (v == value)
+               return 0;
+
+       return -EIO;
+}
+
 static int tpacpi_battery_probe(int battery)
 {
        int ret = 0;
@@ -9340,6 +9387,8 @@ 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)) {
@@ -9376,10 +9425,25 @@ 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;
 }
@@ -9514,6 +9578,28 @@ 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)
@@ -9528,8 +9614,44 @@ 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 = 0;
+       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:
+               if (available & BIT(POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE))
+                       ret = tpacpi_battery_set_validate(FORCE_DISCHARGE, battery, 0);
+               if (ret < 0)
+                       return ret;
+               break;
+       case POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE:
+               ret = tpacpi_battery_set_validate(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,
@@ -9548,6 +9670,7 @@ 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,
 };