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platform/x86: system76_acpi: Add battery charging thresholds

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System76 laptops running open source EC firmware support configuring
charging thresholds through ACPI methods. Expose this functionality
through the standard sysfs entries charge_control_{start,end}_threshold.

Signed-off-by: Tim Crawford <tcrawford@system76.com>
Link: https://lore.kernel.org/r/20211006202202.7479-4-tcrawford@system76.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Tim Crawford 2021-10-06 14:22:01 -06:00 committed by Hans de Goede
parent 0de30fc684
commit 76f7eba3e0
1 changed files with 157 additions and 0 deletions
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157
drivers/platform/x86/system76_acpi.c
View File

@ -18,8 +18,12 @@
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/pci_ids.h>
#include <linux/power_supply.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <acpi/battery.h>
struct system76_data {
struct acpi_device *acpi_dev;
struct led_classdev ap_led;
@ -143,6 +147,154 @@ static int system76_set(struct system76_data *data, char *method, int value)
return -1;
}
#define BATTERY_THRESHOLD_INVALID 0xFF
enum {
THRESHOLD_START,
THRESHOLD_END,
};
static ssize_t battery_get_threshold(int which, char *buf)
{
struct acpi_object_list input;
union acpi_object param;
acpi_handle handle;
acpi_status status;
unsigned long long ret = BATTERY_THRESHOLD_INVALID;
handle = ec_get_handle();
if (!handle)
return -ENODEV;
input.count = 1;
input.pointer = &param;
// Start/stop selection
param.type = ACPI_TYPE_INTEGER;
param.integer.value = which;
status = acpi_evaluate_integer(handle, "GBCT", &input, &ret);
if (ACPI_FAILURE(status))
return -EIO;
if (ret == BATTERY_THRESHOLD_INVALID)
return -EINVAL;
return sysfs_emit(buf, "%d\n", (int)ret);
}
static ssize_t battery_set_threshold(int which, const char *buf, size_t count)
{
struct acpi_object_list input;
union acpi_object params[2];
acpi_handle handle;
acpi_status status;
unsigned int value;
int ret;
handle = ec_get_handle();
if (!handle)
return -ENODEV;
ret = kstrtouint(buf, 10, &value);
if (ret)
return ret;
if (value > 100)
return -EINVAL;
input.count = 2;
input.pointer = params;
// Start/stop selection
params[0].type = ACPI_TYPE_INTEGER;
params[0].integer.value = which;
// Threshold value
params[1].type = ACPI_TYPE_INTEGER;
params[1].integer.value = value;
status = acpi_evaluate_object(handle, "SBCT", &input, NULL);
if (ACPI_FAILURE(status))
return -EIO;
return count;
}
static ssize_t charge_control_start_threshold_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return battery_get_threshold(THRESHOLD_START, buf);
}
static ssize_t charge_control_start_threshold_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
return battery_set_threshold(THRESHOLD_START, buf, count);
}
static DEVICE_ATTR_RW(charge_control_start_threshold);
static ssize_t charge_control_end_threshold_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return battery_get_threshold(THRESHOLD_END, buf);
}
static ssize_t charge_control_end_threshold_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
return battery_set_threshold(THRESHOLD_END, buf, count);
}
static DEVICE_ATTR_RW(charge_control_end_threshold);
static struct attribute *system76_battery_attrs[] = {
&dev_attr_charge_control_start_threshold.attr,
&dev_attr_charge_control_end_threshold.attr,
NULL,
};
ATTRIBUTE_GROUPS(system76_battery);
static int system76_battery_add(struct power_supply *battery)
{
// System76 EC only supports 1 battery
if (strcmp(battery->desc->name, "BAT0") != 0)
return -ENODEV;
if (device_add_groups(&battery->dev, system76_battery_groups))
return -ENODEV;
return 0;
}
static int system76_battery_remove(struct power_supply *battery)
{
device_remove_groups(&battery->dev, system76_battery_groups);
return 0;
}
static struct acpi_battery_hook system76_battery_hook = {
.add_battery = system76_battery_add,
.remove_battery = system76_battery_remove,
.name = "System76 Battery Extension",
};
static void system76_battery_init(void)
{
acpi_handle handle;
handle = ec_get_handle();
if (handle && acpi_has_method(handle, "GBCT"))
battery_hook_register(&system76_battery_hook);
}
static void system76_battery_exit(void)
{
acpi_handle handle;
handle = ec_get_handle();
if (handle && acpi_has_method(handle, "GBCT"))
battery_hook_unregister(&system76_battery_hook);
}
// Get the airplane mode LED brightness
static enum led_brightness ap_led_get(struct led_classdev *led)
{
@ -581,6 +733,8 @@ static int system76_add(struct acpi_device *acpi_dev)
if (err)
goto error;
system76_battery_init();
return 0;
error:
@ -596,6 +750,9 @@ static int system76_remove(struct acpi_device *acpi_dev)
struct system76_data *data;
data = acpi_driver_data(acpi_dev);
system76_battery_exit();
if (data->kb_color >= 0)
device_remove_file(data->kb_led.dev, &kb_led_color_dev_attr);