v4.19.13 snapshot.
diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
new file mode 100644
index 0000000..cdd3136
--- /dev/null
+++ b/drivers/acpi/ac.c
@@ -0,0 +1,488 @@
+/*
+ *  acpi_ac.c - ACPI AC Adapter Driver ($Revision: 27 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/dmi.h>
+#include <linux/delay.h>
+#ifdef CONFIG_ACPI_PROCFS_POWER
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/acpi.h>
+#include <acpi/battery.h>
+
+#define PREFIX "ACPI: "
+
+#define ACPI_AC_CLASS			"ac_adapter"
+#define ACPI_AC_DEVICE_NAME		"AC Adapter"
+#define ACPI_AC_FILE_STATE		"state"
+#define ACPI_AC_NOTIFY_STATUS		0x80
+#define ACPI_AC_STATUS_OFFLINE		0x00
+#define ACPI_AC_STATUS_ONLINE		0x01
+#define ACPI_AC_STATUS_UNKNOWN		0xFF
+
+#define _COMPONENT		ACPI_AC_COMPONENT
+ACPI_MODULE_NAME("ac");
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION("ACPI AC Adapter Driver");
+MODULE_LICENSE("GPL");
+
+
+static int acpi_ac_add(struct acpi_device *device);
+static int acpi_ac_remove(struct acpi_device *device);
+static void acpi_ac_notify(struct acpi_device *device, u32 event);
+
+struct acpi_ac_bl {
+	const char *hid;
+	int hrv;
+};
+
+static const struct acpi_device_id ac_device_ids[] = {
+	{"ACPI0003", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, ac_device_ids);
+
+/* Lists of PMIC ACPI HIDs with an (often better) native charger driver */
+static const struct acpi_ac_bl acpi_ac_blacklist[] = {
+	{ "INT33F4", -1 }, /* X-Powers AXP288 PMIC */
+	{ "INT34D3",  3 }, /* Intel Cherrytrail Whiskey Cove PMIC */
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_ac_resume(struct device *dev);
+#endif
+static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume);
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+extern struct proc_dir_entry *acpi_lock_ac_dir(void);
+extern void *acpi_unlock_ac_dir(struct proc_dir_entry *acpi_ac_dir);
+#endif
+
+
+static int ac_sleep_before_get_state_ms;
+static int ac_check_pmic = 1;
+
+static struct acpi_driver acpi_ac_driver = {
+	.name = "ac",
+	.class = ACPI_AC_CLASS,
+	.ids = ac_device_ids,
+	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
+	.ops = {
+		.add = acpi_ac_add,
+		.remove = acpi_ac_remove,
+		.notify = acpi_ac_notify,
+		},
+	.drv.pm = &acpi_ac_pm,
+};
+
+struct acpi_ac {
+	struct power_supply *charger;
+	struct power_supply_desc charger_desc;
+	struct acpi_device * device;
+	unsigned long long state;
+	struct notifier_block battery_nb;
+};
+
+#define to_acpi_ac(x) power_supply_get_drvdata(x)
+
+/* --------------------------------------------------------------------------
+                               AC Adapter Management
+   -------------------------------------------------------------------------- */
+
+static int acpi_ac_get_state(struct acpi_ac *ac)
+{
+	acpi_status status = AE_OK;
+
+	if (!ac)
+		return -EINVAL;
+
+	status = acpi_evaluate_integer(ac->device->handle, "_PSR", NULL,
+				       &ac->state);
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status,
+				"Error reading AC Adapter state"));
+		ac->state = ACPI_AC_STATUS_UNKNOWN;
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+                            sysfs I/F
+   -------------------------------------------------------------------------- */
+static int get_ac_property(struct power_supply *psy,
+			   enum power_supply_property psp,
+			   union power_supply_propval *val)
+{
+	struct acpi_ac *ac = to_acpi_ac(psy);
+
+	if (!ac)
+		return -ENODEV;
+
+	if (acpi_ac_get_state(ac))
+		return -ENODEV;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = ac->state;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static enum power_supply_property ac_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+/* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+
+static struct proc_dir_entry *acpi_ac_dir;
+
+static int acpi_ac_seq_show(struct seq_file *seq, void *offset)
+{
+	struct acpi_ac *ac = seq->private;
+
+
+	if (!ac)
+		return 0;
+
+	if (acpi_ac_get_state(ac)) {
+		seq_puts(seq, "ERROR: Unable to read AC Adapter state\n");
+		return 0;
+	}
+
+	seq_puts(seq, "state:                   ");
+	switch (ac->state) {
+	case ACPI_AC_STATUS_OFFLINE:
+		seq_puts(seq, "off-line\n");
+		break;
+	case ACPI_AC_STATUS_ONLINE:
+		seq_puts(seq, "on-line\n");
+		break;
+	default:
+		seq_puts(seq, "unknown\n");
+		break;
+	}
+
+	return 0;
+}
+
+static int acpi_ac_add_fs(struct acpi_ac *ac)
+{
+	struct proc_dir_entry *entry = NULL;
+
+	printk(KERN_WARNING PREFIX "Deprecated procfs I/F for AC is loaded,"
+			" please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
+	if (!acpi_device_dir(ac->device)) {
+		acpi_device_dir(ac->device) =
+			proc_mkdir(acpi_device_bid(ac->device), acpi_ac_dir);
+		if (!acpi_device_dir(ac->device))
+			return -ENODEV;
+	}
+
+	/* 'state' [R] */
+	entry = proc_create_single_data(ACPI_AC_FILE_STATE, S_IRUGO,
+			acpi_device_dir(ac->device), acpi_ac_seq_show, ac);
+	if (!entry)
+		return -ENODEV;
+	return 0;
+}
+
+static int acpi_ac_remove_fs(struct acpi_ac *ac)
+{
+
+	if (acpi_device_dir(ac->device)) {
+		remove_proc_entry(ACPI_AC_FILE_STATE,
+				  acpi_device_dir(ac->device));
+		remove_proc_entry(acpi_device_bid(ac->device), acpi_ac_dir);
+		acpi_device_dir(ac->device) = NULL;
+	}
+
+	return 0;
+}
+#endif
+
+/* --------------------------------------------------------------------------
+                                   Driver Model
+   -------------------------------------------------------------------------- */
+
+static void acpi_ac_notify(struct acpi_device *device, u32 event)
+{
+	struct acpi_ac *ac = acpi_driver_data(device);
+
+	if (!ac)
+		return;
+
+	switch (event) {
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Unsupported event [0x%x]\n", event));
+	/* fall through */
+	case ACPI_AC_NOTIFY_STATUS:
+	case ACPI_NOTIFY_BUS_CHECK:
+	case ACPI_NOTIFY_DEVICE_CHECK:
+		/*
+		 * A buggy BIOS may notify AC first and then sleep for
+		 * a specific time before doing actual operations in the
+		 * EC event handler (_Qxx). This will cause the AC state
+		 * reported by the ACPI event to be incorrect, so wait for a
+		 * specific time for the EC event handler to make progress.
+		 */
+		if (ac_sleep_before_get_state_ms > 0)
+			msleep(ac_sleep_before_get_state_ms);
+
+		acpi_ac_get_state(ac);
+		acpi_bus_generate_netlink_event(device->pnp.device_class,
+						  dev_name(&device->dev), event,
+						  (u32) ac->state);
+		acpi_notifier_call_chain(device, event, (u32) ac->state);
+		kobject_uevent(&ac->charger->dev.kobj, KOBJ_CHANGE);
+	}
+
+	return;
+}
+
+static int acpi_ac_battery_notify(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct acpi_ac *ac = container_of(nb, struct acpi_ac, battery_nb);
+	struct acpi_bus_event *event = (struct acpi_bus_event *)data;
+
+	/*
+	 * On HP Pavilion dv6-6179er AC status notifications aren't triggered
+	 * when adapter is plugged/unplugged. However, battery status
+	 * notifcations are triggered when battery starts charging or
+	 * discharging. Re-reading AC status triggers lost AC notifications,
+	 * if AC status has changed.
+	 */
+	if (strcmp(event->device_class, ACPI_BATTERY_CLASS) == 0 &&
+	    event->type == ACPI_BATTERY_NOTIFY_STATUS)
+		acpi_ac_get_state(ac);
+
+	return NOTIFY_OK;
+}
+
+static int __init thinkpad_e530_quirk(const struct dmi_system_id *d)
+{
+	ac_sleep_before_get_state_ms = 1000;
+	return 0;
+}
+
+static int __init ac_do_not_check_pmic_quirk(const struct dmi_system_id *d)
+{
+	ac_check_pmic = 0;
+	return 0;
+}
+
+static const struct dmi_system_id ac_dmi_table[]  __initconst = {
+	{
+	/* Thinkpad e530 */
+	.callback = thinkpad_e530_quirk,
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		DMI_MATCH(DMI_PRODUCT_NAME, "32597CG"),
+		},
+	},
+	{
+		/* ECS EF20EA */
+		.callback = ac_do_not_check_pmic_quirk,
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_NAME, "EF20EA"),
+		},
+	},
+	{
+		/* Lenovo Ideapad Miix 320 */
+		.callback = ac_do_not_check_pmic_quirk,
+		.matches = {
+		  DMI_EXACT_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "80XF"),
+		  DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Lenovo MIIX 320-10ICR"),
+		},
+	},
+	{},
+};
+
+static int acpi_ac_add(struct acpi_device *device)
+{
+	struct power_supply_config psy_cfg = {};
+	int result = 0;
+	struct acpi_ac *ac = NULL;
+
+
+	if (!device)
+		return -EINVAL;
+
+	ac = kzalloc(sizeof(struct acpi_ac), GFP_KERNEL);
+	if (!ac)
+		return -ENOMEM;
+
+	ac->device = device;
+	strcpy(acpi_device_name(device), ACPI_AC_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_AC_CLASS);
+	device->driver_data = ac;
+
+	result = acpi_ac_get_state(ac);
+	if (result)
+		goto end;
+
+	psy_cfg.drv_data = ac;
+
+	ac->charger_desc.name = acpi_device_bid(device);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	result = acpi_ac_add_fs(ac);
+	if (result)
+		goto end;
+#endif
+	ac->charger_desc.type = POWER_SUPPLY_TYPE_MAINS;
+	ac->charger_desc.properties = ac_props;
+	ac->charger_desc.num_properties = ARRAY_SIZE(ac_props);
+	ac->charger_desc.get_property = get_ac_property;
+	ac->charger = power_supply_register(&ac->device->dev,
+					    &ac->charger_desc, &psy_cfg);
+	if (IS_ERR(ac->charger)) {
+		result = PTR_ERR(ac->charger);
+		goto end;
+	}
+
+	printk(KERN_INFO PREFIX "%s [%s] (%s)\n",
+	       acpi_device_name(device), acpi_device_bid(device),
+	       ac->state ? "on-line" : "off-line");
+
+	ac->battery_nb.notifier_call = acpi_ac_battery_notify;
+	register_acpi_notifier(&ac->battery_nb);
+end:
+	if (result) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+		acpi_ac_remove_fs(ac);
+#endif
+		kfree(ac);
+	}
+
+	return result;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_ac_resume(struct device *dev)
+{
+	struct acpi_ac *ac;
+	unsigned old_state;
+
+	if (!dev)
+		return -EINVAL;
+
+	ac = acpi_driver_data(to_acpi_device(dev));
+	if (!ac)
+		return -EINVAL;
+
+	old_state = ac->state;
+	if (acpi_ac_get_state(ac))
+		return 0;
+	if (old_state != ac->state)
+		kobject_uevent(&ac->charger->dev.kobj, KOBJ_CHANGE);
+	return 0;
+}
+#else
+#define acpi_ac_resume NULL
+#endif
+
+static int acpi_ac_remove(struct acpi_device *device)
+{
+	struct acpi_ac *ac = NULL;
+
+
+	if (!device || !acpi_driver_data(device))
+		return -EINVAL;
+
+	ac = acpi_driver_data(device);
+
+	power_supply_unregister(ac->charger);
+	unregister_acpi_notifier(&ac->battery_nb);
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_ac_remove_fs(ac);
+#endif
+
+	kfree(ac);
+
+	return 0;
+}
+
+static int __init acpi_ac_init(void)
+{
+	unsigned int i;
+	int result;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	dmi_check_system(ac_dmi_table);
+
+	if (ac_check_pmic) {
+		for (i = 0; i < ARRAY_SIZE(acpi_ac_blacklist); i++)
+			if (acpi_dev_present(acpi_ac_blacklist[i].hid, "1",
+					     acpi_ac_blacklist[i].hrv)) {
+				pr_info(PREFIX "AC: found native %s PMIC, not loading\n",
+					acpi_ac_blacklist[i].hid);
+				return -ENODEV;
+			}
+	}
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_ac_dir = acpi_lock_ac_dir();
+	if (!acpi_ac_dir)
+		return -ENODEV;
+#endif
+
+
+	result = acpi_bus_register_driver(&acpi_ac_driver);
+	if (result < 0) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+		acpi_unlock_ac_dir(acpi_ac_dir);
+#endif
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void __exit acpi_ac_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_ac_driver);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_unlock_ac_dir(acpi_ac_dir);
+#endif
+}
+module_init(acpi_ac_init);
+module_exit(acpi_ac_exit);