On Sun, May 13, 2018 at 05:29:37PM +0200, Ognjen Galic wrote:
> 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
This comment does not adhere to the Linux coding style
> + * 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)
I'm not sure, but maybe `if (value < 2)` is better here?
> + 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
>
