platform/x86: lg-laptop: Support for battery charge limit on newer models

Add support for the difference between various models:

- Use dmi to detect laptop model.
- 2019 and newer models use _wmbb method to set battery charge limit.
Signed-off-by: Matan Ziv-Av <matan@svgalib.org>
Link: https://lore.kernel.org/r/bd6922a412e50c2dcfb7ce24fc8687f577181d65.1629291912.git.matan@svgalib.orgReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/lg-laptop.c

@@ -8,6 +8,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/acpi.h>
+#include <linux/dmi.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>
 #include <linux/kernel.h>
@@ -69,6 +70,8 @@ static u32 inited;
 #define INIT_INPUT_ACPI         0x04
 #define INIT_SPARSE_KEYMAP      0x80
 
+static int battery_limit_use_wmbb;
+
 static const struct key_entry wmi_keymap[] = {
 	{KE_KEY, 0x70, {KEY_F15} },	 /* LG control panel (F1) */
 	{KE_KEY, 0x74, {KEY_F13} },	 /* Touchpad toggle (F5) */
@@ -461,7 +464,10 @@ static ssize_t battery_care_limit_store(struct device *dev,
 	if (value == 100 || value == 80) {
 		union acpi_object *r;
 
-		r = lg_wmab(WM_BATT_LIMIT, WM_SET, value);
+		if (battery_limit_use_wmbb)
+			r = lg_wmbb(WMBB_BATT_LIMIT, WM_SET, value);
+		else
+			r = lg_wmab(WM_BATT_LIMIT, WM_SET, value);
 		if (!r)
 			return -EIO;
 
@@ -479,16 +485,29 @@ static ssize_t battery_care_limit_show(struct device *dev,
 	unsigned int status;
 	union acpi_object *r;
 
-	r = lg_wmab(WM_BATT_LIMIT, WM_GET, 0);
-	if (!r)
-		return -EIO;
+	if (battery_limit_use_wmbb) {
+		r = lg_wmbb(WMBB_BATT_LIMIT, WM_GET, 0);
+		if (!r)
+			return -EIO;
 
-	if (r->type != ACPI_TYPE_INTEGER) {
-		kfree(r);
-		return -EIO;
-	}
+		if (r->type != ACPI_TYPE_BUFFER) {
+			kfree(r);
+			return -EIO;
+		}
 
-	status = r->integer.value;
+		status = r->buffer.pointer[0x10];
+	} else {
+		r = lg_wmab(WM_BATT_LIMIT, WM_GET, 0);
+		if (!r)
+			return -EIO;
+
+		if (r->type != ACPI_TYPE_INTEGER) {
+			kfree(r);
+			return -EIO;
+		}
+
+		status = r->integer.value;
+	}
 	kfree(r);
 	if (status != 80 && status != 100)
 		status = 0;
@@ -602,6 +621,8 @@ static struct platform_driver pf_driver = {
 static int acpi_add(struct acpi_device *device)
 {
 	int ret;
+	const char *product;
+	int year = 2017;
 
 	if (pf_device)
 		return 0;
@@ -619,6 +640,42 @@ static int acpi_add(struct acpi_device *device)
 		pr_err("unable to register platform device\n");
 		goto out_platform_registered;
 	}
+	product = dmi_get_system_info(DMI_PRODUCT_NAME);
+	if (strlen(product) > 4)
+		switch (product[4]) {
+		case '5':
+		case '6':
+			year = 2016;
+			break;
+		case '7':
+			year = 2017;
+			break;
+		case '8':
+			year = 2018;
+			break;
+		case '9':
+			year = 2019;
+			break;
+		case '0':
+			if (strlen(product) > 5)
+				switch (product[5]) {
+				case 'N':
+					year = 2020;
+					break;
+				case 'P':
+					year = 2021;
+					break;
+				default:
+					year = 2022;
+				}
+			break;
+		default:
+			year = 2019;
+		}
+	pr_info("product: %s  year: %d\n", product, year);
+
+	if (year >= 2019)
+		battery_limit_use_wmbb = 1;
 
 	ret = sysfs_create_group(&pf_device->dev.kobj, &dev_attribute_group);
 	if (ret)