Lenovo ThinkPad systems support the prevention of
battery charging via a manual override called Inhibit Charge.
This patch adds support for that attribute and exposes it via the
battery ACPI driver in the generic location:
/sys/class/power_supply/BATX/inhibit_charge
Signed-off-by: Ognjen Galic <smclt30p@xxxxxxxxx>
---
drivers/platform/x86/thinkpad_acpi.c | 66 +++++++++++++++++++++++++++-
1 file changed, 64 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index da1ca485..b8b74889 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -9233,6 +9233,11 @@ static struct ibm_struct mute_led_driver_data = {
#define GET_STOP "BCSG"
#define SET_STOP "BCSS"
+#define SET_INHIBIT "BICS"
+#define GET_INHIBIT "BICG"
+
+#define INHIBIT_ATTR "inhibit_charge"
+
#define START_ATTR "charge_start_threshold"
#define STOP_ATTR "charge_stop_threshold"
@@ -9251,6 +9256,7 @@ enum {
/* This is used in the get/set helpers */
THRESHOLD_START,
THRESHOLD_STOP,
+ INHIBIT_CHARGE
};
struct tpacpi_battery_data {
@@ -9258,6 +9264,7 @@ struct tpacpi_battery_data {
int start_support;
int charge_stop;
int stop_support;
+ int inhibit_support;
};
struct tpacpi_battery_driver_data {
@@ -9315,6 +9322,13 @@ static int tpacpi_battery_get(int what, int battery, int *ret)
if (*ret == 0)
*ret = 100;
return 0;
+ case INHIBIT_CHARGE:
+ if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_INHIBIT, ret, battery))
+ return -ENODEV;
+
+ /* The inhibit charge status is in the first bit */
+ *ret = *ret & 0x01;
+ return 0;
default:
pr_crit("wrong parameter: %d", what);
return -EINVAL;
@@ -9343,6 +9357,21 @@ static int tpacpi_battery_set(int what, int battery, int value)
return -ENODEV;
}
return 0;
+ case INHIBIT_CHARGE:
+ /* When setting inhbitit charge, we set a default vaulue 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 and 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;
@@ -9359,6 +9388,8 @@ static int tpacpi_battery_probe(int battery)
* 2) Check for support
* 3) Get the current stop threshold
* 4) Check for support
+ * 5) Check for inhibit charge support
+ * 6) Get the current inhibit charge status
*/
if (acpi_has_method(hkey_handle, GET_START)) {
if ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_START, &ret, battery)) {
@@ -9395,10 +9426,16 @@ static int tpacpi_battery_probe(int battery)
return -ENODEV;
}
}
- pr_info("battery %d registered (start %d, stop %d)",
+ if (acpi_has_method(hkey_handle, GET_INHIBIT))
+ if (!ACPI_FAILURE(tpacpi_battery_acpi_eval(GET_INHIBIT, &ret, battery)))
+ /* Support is marked in bit 5 */
+ battery_info.batteries[battery].inhibit_support = ret & BIT(5);
+
+ pr_info("battery %d registered (start %d, stop %d, inhibit: %d)",
battery,
battery_info.batteries[battery].charge_start,
- battery_info.batteries[battery].charge_stop);
+ battery_info.batteries[battery].charge_stop,
+ battery_info.batteries[battery].inhibit_support);
return 0;
}
@@ -9484,6 +9521,15 @@ static ssize_t tpacpi_battery_store(int what,
if (tpacpi_battery_set(THRESHOLD_STOP, battery, value))
return -EINVAL;
return count;
+ case INHIBIT_CHARGE:
+ if (!battery_info.batteries[battery].inhibit_support)
+ return -ENODEV;
+ /* The only valid values are 1 and 0 */
+ if (value != 0 && value != 1)
+ return -EINVAL;
+ if (tpacpi_battery_set(INHIBIT_CHARGE, battery, value))
+ return -ENODEV;
+ return count;
default:
pr_crit("Wrong parameter: %d", what);
return -EINVAL;
@@ -9546,12 +9592,28 @@ static ssize_t charge_stop_threshold_store(struct device *dev,
return tpacpi_battery_store(THRESHOLD_STOP, dev, buf, count);
}
+static ssize_t inhibit_charge_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return tpacpi_battery_store(INHIBIT_CHARGE, dev, buf, count);
+}
+
+static ssize_t inhibit_charge_show(struct device *device,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return tpacpi_battery_show(INHIBIT_CHARGE, device, buf);
+}
+
static DEVICE_ATTR_RW(charge_start_threshold);
static DEVICE_ATTR_RW(charge_stop_threshold);
+static DEVICE_ATTR_RW(inhibit_charge);
static struct attribute *tpacpi_battery_attrs[] = {
&dev_attr_charge_start_threshold.attr,
&dev_attr_charge_stop_threshold.attr,
+ &dev_attr_inhibit_charge.attr,
NULL,
};
--
2.17.0
