Add version checking to Battery patches to fix incompatability with t…

…he 4.5 kernel

Adding in a few kernel version checks using 4.19.0 as the basis of a ktime_t type change makes older kernels incapable of working with the new code. Reintroduced some of the old code to ensure old functionality stays when the user is below 4.19.0.

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        kernel: ["6.3", "5.10", "4.14", "4.6", "4.5", "4.1", "3.19", "3.18", "3.17", "3.7"]
+        kernel: ["6.3", "5.10", "4.19", "4.14", "4.6", "4.5", "4.1", "3.19", "3.18", "3.17", "3.7"]
         include:
           - kernel: "3.7"
             compile_cflags: -fno-pie -Wno-error=pointer-sign
@@ -34,6 +34,8 @@ jobs:
             prepare_cflags: -fno-pie -no-pie
           - kernel: "4.14"
             compile_cflags: -Wno-error=format-truncation -Wno-error=pointer-sign
+          - kernel: "4.19"
+            compile_cflags: -Wno-error=format-truncation -Wno-error=pointer-sign
           - kernel: "5.10"
             compile_cflags: -Wno-error=format-truncation -Wno-error=pointer-sign
           - kernel: "6.3"

4.5/wacom.h

@@ -166,7 +166,9 @@ struct wacom_remote {
 		struct input_dev *input;
 		bool registered;
 		struct wacom_battery battery;
+		#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 		ktime_t active_time;
+		#endif
 	} remotes[WACOM_MAX_REMOTES];
 };
 

4.5/wacom_sys.c

@@ -2585,6 +2585,7 @@ static void wacom_wireless_work(struct work_struct *work)
 	return;
 }
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 static void wacom_remote_destroy_battery(struct wacom *wacom, int index)
 {
 	struct wacom_remote *remote = wacom->remote;
@@ -2596,6 +2597,7 @@ static void wacom_remote_destroy_battery(struct wacom *wacom, int index)
 		remote->remotes[index].active_time = 0;
 	}
 }
+#endif
 
 static void wacom_remote_destroy_one(struct wacom *wacom, unsigned int index)
 {
@@ -2610,15 +2612,23 @@ static void wacom_remote_destroy_one(struct wacom *wacom, unsigned int index)
 			spin_lock_irqsave(&remote->remote_lock, flags);
 			remote->remotes[i].registered = false;
 			spin_unlock_irqrestore(&remote->remote_lock, flags);
-
+			#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 			wacom_remote_destroy_battery(wacom, i);
+			#else
+			if (remote->remotes[i].battery.battery)
+				devres_release_group(&wacom->hdev->dev,
+						     &remote->remotes[i].battery.bat_desc);
+			#endif
 
 			if (remote->remotes[i].group.name)
 				devres_release_group(&wacom->hdev->dev,
 						     &remote->remotes[i]);
 
 			remote->remotes[i].serial = 0;
 			remote->remotes[i].group.name = NULL;
+			#if LINUX_VERSION_CODE < KERNEL_VERSION(4,19,0)
+			remote->remotes[i].battery.battery = NULL;
+			#endif
 			wacom->led.groups[i].select = WACOM_STATUS_UNKNOWN;
 		}
 	}
@@ -2702,9 +2712,11 @@ static int wacom_remote_attach_battery(struct wacom *wacom, int index)
 
 	if (remote->remotes[index].battery.battery)
 		return 0;
-
+
+	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 	if (!remote->remotes[index].active_time)
 		return 0;
+	#endif
 
 	if (wacom->led.groups[index].select == WACOM_STATUS_UNKNOWN)
 		return 0;
@@ -2721,7 +2733,9 @@ static void wacom_remote_work(struct work_struct *work)
 {
 	struct wacom *wacom = container_of(work, struct wacom, remote_work);
 	struct wacom_remote *remote = wacom->remote;
+	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 	ktime_t kt = ktime_get();
+	#endif
 	struct wacom_remote_work_data remote_work_data;
 	unsigned long flags;
 	unsigned int count;
@@ -2747,11 +2761,16 @@ static void wacom_remote_work(struct work_struct *work)
 
 	for (i = 0; i < WACOM_MAX_REMOTES; i++) {
 		work_serial = remote_work_data.remote[i].serial;
+
+		#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 		if (work_serial) {
 
 			if (kt - remote->remotes[i].active_time > WACOM_REMOTE_BATTERY_TIMEOUT
 			    && remote->remotes[i].active_time != 0)
 				wacom_remote_destroy_battery(wacom, i);
+		#else
+		if (remote_work_data.remote[i].connected) {
+		#endif
 
 			if (remote->remotes[i].serial == work_serial) {
 				wacom_remote_attach_battery(wacom, i);

4.5/wacom_wac.c

@@ -1143,8 +1143,11 @@ static int wacom_remote_irq(struct wacom_wac *wacom_wac, size_t len)
 
 	if (index < 0 || !remote->remotes[index].registered)
 		goto out;
-
+
+	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 	remote->remotes[i].active_time = ktime_get();
+	#endif
+
 	input = remote->remotes[index].input;
 
 	input_report_key(input, BTN_0, (data[9] & 0x01));
@@ -1219,7 +1222,10 @@ static void wacom_remote_status_irq(struct wacom_wac *wacom_wac, size_t len)
 	for (i = 0; i < WACOM_MAX_REMOTES; i++) {
 		int j = i * 6;
 		int serial = (data[j+6] << 16) + (data[j+5] << 8) + data[j+4];
-
+		#if LINUX_VERSION_CODE < KERNEL_VERSION(4,19,0)
+		bool connected = data[j+2];
+		remote_data.remote[i].connected = connected;
+		#endif
 		remote_data.remote[i].serial = serial;
 	}
 

4.5/wacom_wac.h

@@ -8,14 +8,17 @@
 #include <linux/types.h>
 #include <linux/hid.h>
 #include <linux/kfifo.h>
+#include <linux/version.h>
 
 /* maximum packet length for USB/BT devices */
 #define WACOM_PKGLEN_MAX	361
 
 #define WACOM_NAME_MAX		64
 #define WACOM_MAX_REMOTES	5
 #define WACOM_STATUS_UNKNOWN	255
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
 #define WACOM_REMOTE_BATTERY_TIMEOUT	21000000000ll
+#endif
 
 /* packet length for individual models */
 #define WACOM_PKGLEN_BBFUN	 9
@@ -359,6 +362,9 @@ struct hid_data {
 struct wacom_remote_work_data {
 	struct {
 		u32 serial;
+		#if LINUX_VERSION_CODE < KERNEL_VERSION(4,19,0)
+		bool connected;
+		#endif
 	} remote[WACOM_MAX_REMOTES];
 };