Control battery charge thresholds through the battery API and driver's
attributes.
Setting battery charging thresholds can introduce a race condition with
MACH-WX9 where two or more threads are trying to read/write values
from/to EC memory.
Signed-off-by: Ayman Bagabas <ayman.bagabas@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 1 +
drivers/platform/x86/huawei-wmi.c | 212 ++++++++++++++++++++++++++++++
2 files changed, 213 insertions(+)
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 754405e19ef1..e64103789885 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1306,6 +1306,7 @@ config INTEL_ATOMISP2_PM
config HUAWEI_WMI
tristate "Huawei WMI laptop extras driver"
+ depends on ACPI_BATTERY
depends on ACPI_WMI
depends on INPUT
select INPUT_SPARSEKMAP
diff --git a/drivers/platform/x86/huawei-wmi.c b/drivers/platform/x86/huawei-wmi.c
index 41904b1cc284..6e791f9ffc26 100644
--- a/drivers/platform/x86/huawei-wmi.c
+++ b/drivers/platform/x86/huawei-wmi.c
@@ -6,6 +6,7 @@
*/
#include <linux/acpi.h>
+#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
@@ -13,7 +14,10 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/sysfs.h>
#include <linux/wmi.h>
+#include <acpi/battery.h>
/*
* Huawei WMI GUIDs
@@ -49,10 +53,13 @@ struct quirk_entry {
static struct quirk_entry *quirks;
struct huawei_wmi {
+ bool battery_available;
+
struct input_dev *idev[2];
struct led_classdev cdev;
struct platform_device *pdev;
+ struct mutex battery_lock;
struct mutex wmi_lock;
};
@@ -300,6 +307,208 @@ static void huawei_wmi_leds_setup(struct device *dev)
devm_led_classdev_register(dev, &huawei->cdev);
}
+/* Battery protection */
+
+static int huawei_wmi_battery_get(int *start, int *end)
+{
+ u8 ret[0x100];
+ int err, i;
+
+ err = huawei_wmi_cmd(BATTERY_THRESH_GET, ret, 0x100);
+ if (err)
+ return err;
+
+ /* Find the last two non-zero values. Return status is ignored. */
+ i = 0xff;
+ do {
+ if (start)
+ *start = ret[i-1];
+ if (end)
+ *end = ret[i];
+ } while (i > 2 && !ret[i--]);
+
+ return 0;
+}
+
+static int huawei_wmi_battery_set(int start, int end)
+{
+ union hwmi_arg arg;
+ int err;
+
+ if (start < 0 || end > 100)
+ return -EINVAL;
+
+ arg.cmd = BATTERY_THRESH_SET;
+ arg.args[2] = start;
+ arg.args[3] = end;
+
+ /* This is an edge case were some models turn battery protection
+ * off without changing their thresholds values. We clear the
+ * values before turning off protection. Sometimes we need a sleep delay to
+ * make sure these values make their way to EC memory.
+ */
+ if (quirks && quirks->battery_reset && start == 0 && end == 100) {
+ err = huawei_wmi_battery_set(0, 0);
+ if (err)
+ return err;
+
+ msleep(1000);
+ }
+
+ err = huawei_wmi_cmd(arg.cmd, NULL, 0);
+
+ return err;
+}
+
+static ssize_t charge_control_start_threshold_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int err, start;
+
+ err = huawei_wmi_battery_get(&start, NULL);
+ if (err)
+ return err;
+
+ return sprintf(buf, "%d\n", start);
+}
+
+static ssize_t charge_control_end_threshold_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int err, end;
+
+ err = huawei_wmi_battery_get(NULL, &end);
+ if (err)
+ return err;
+
+ return sprintf(buf, "%d\n", end);
+}
+
+static ssize_t charge_control_thresholds_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int err, start, end;
+
+ err = huawei_wmi_battery_get(&start, &end);
+ if (err)
+ return err;
+
+ return sprintf(buf, "%d %d\n", start, end);
+}
+
+static ssize_t charge_control_start_threshold_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int err, start, end;
+
+ err = huawei_wmi_battery_get(NULL, &end);
+ if (err)
+ return err;
+
+ if (sscanf(buf, "%d", &start) != 1)
+ return -EINVAL;
+
+ err = huawei_wmi_battery_set(start, end);
+ if (err)
+ return err;
+
+ return size;
+}
+
+static ssize_t charge_control_end_threshold_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int err, start, end;
+
+ err = huawei_wmi_battery_get(&start, NULL);
+ if (err)
+ return err;
+
+ if (sscanf(buf, "%d", &end) != 1)
+ return -EINVAL;
+
+ err = huawei_wmi_battery_set(start, end);
+ if (err)
+ return err;
+
+ return size;
+}
+
+static ssize_t charge_control_thresholds_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int err, start, end;
+
+ if (sscanf(buf, "%d %d", &start, &end) != 2)
+ return -EINVAL;
+
+ err = huawei_wmi_battery_set(start, end);
+ if (err)
+ return err;
+
+ return size;
+}
+
+static DEVICE_ATTR_RW(charge_control_start_threshold);
+static DEVICE_ATTR_RW(charge_control_end_threshold);
+static DEVICE_ATTR_RW(charge_control_thresholds);
+
+static int huawei_wmi_battery_add(struct power_supply *battery)
+{
+ /* Huawei laptops come with one battery only */
+ if (strcmp(battery->desc->name, "BAT") != 1)
+ return -ENODEV;
+
+ device_create_file(&battery->dev, &dev_attr_charge_control_start_threshold);
+ device_create_file(&battery->dev, &dev_attr_charge_control_end_threshold);
+
+ return 0;
+}
+
+static int huawei_wmi_battery_remove(struct power_supply *battery)
+{
+ device_remove_file(&battery->dev, &dev_attr_charge_control_start_threshold);
+ device_remove_file(&battery->dev, &dev_attr_charge_control_end_threshold);
+
+ return 0;
+}
+
+static struct acpi_battery_hook huawei_wmi_battery_hook = {
+ .add_battery = huawei_wmi_battery_add,
+ .remove_battery = huawei_wmi_battery_remove,
+ .name = "Huawei Battery Extension"
+};
+
+static void huawei_wmi_battery_setup(struct device *dev)
+{
+ struct huawei_wmi *huawei = dev_get_drvdata(dev);
+
+ huawei->battery_available = true;
+ if (huawei_wmi_battery_get(NULL, NULL)) {
+ huawei->battery_available = false;
+ return;
+ }
+
+ battery_hook_register(&huawei_wmi_battery_hook);
+ device_create_file(dev, &dev_attr_charge_control_thresholds);
+}
+
+static void huawei_wmi_battery_exit(struct device *dev)
+{
+ struct huawei_wmi *huawei = dev_get_drvdata(dev);
+
+ if (huawei->battery_available) {
+ battery_hook_unregister(&huawei_wmi_battery_hook);
+ device_remove_file(dev, &dev_attr_charge_control_thresholds);
+ }
+}
+
/* Input */
static void huawei_wmi_process_key(struct input_dev *idev, int code)
@@ -420,8 +629,10 @@ static int huawei_wmi_probe(struct platform_device *pdev)
if (wmi_has_guid(HWMI_METHOD_GUID)) {
mutex_init(&huawei_wmi->wmi_lock);
+ mutex_init(&huawei_wmi->battery_lock);
huawei_wmi_leds_setup(&pdev->dev);
+ huawei_wmi_battery_setup(&pdev->dev);
}
return 0;
@@ -439,6 +650,7 @@ static int huawei_wmi_remove(struct platform_device *pdev)
}
if (wmi_has_guid(HWMI_METHOD_GUID)) {
+ huawei_wmi_battery_exit(&pdev->dev);
}
return 0;
--
2.21.0
