acpi_ibm: pass brightness events to evdev(4)

unless the dev.acpi_ibm.0.handlerevents sysctl is set to process
them internally.  The default for the latter is to ignore them,
so passing to evdev(4) is enabled by default.

Reviewed by:		wulf, imp
Tested on:		Lenovo Thinpad X11 Carbon 7Th Gen
Differential Revision:	https://reviews.freebsd.org/D48174

sys/dev/acpi_support/acpi_ibm.c

@@ -37,6 +37,7 @@
  */
 
 #include "opt_acpi.h"
+#include "opt_evdev.h"
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
@@ -55,6 +56,11 @@
 #include <sys/sysctl.h>
 #include <isa/rtc.h>
 
+#ifdef EVDEV_SUPPORT
+#include <dev/evdev/input.h>
+#include <dev/evdev/evdev.h>
+#endif
+
 #define _COMPONENT	ACPI_OEM
 ACPI_MODULE_NAME("IBM")
 
@@ -198,6 +204,9 @@ struct acpi_ibm_softc {
 
 	struct sysctl_ctx_list	*sysctl_ctx;
 	struct sysctl_oid	*sysctl_tree;
+#ifdef EVDEV_SUPPORT
+	struct evdev_dev	*evdev;
+#endif
 };
 
 static struct {
@@ -363,6 +372,9 @@ static driver_t	acpi_ibm_driver = {
 
 DRIVER_MODULE(acpi_ibm, acpi, acpi_ibm_driver, 0, 0);
 MODULE_DEPEND(acpi_ibm, acpi, 1, 1, 1);
+#ifdef EVDEV_SUPPORT
+MODULE_DEPEND(acpi_ibm, evdev, 1, 1, 1);
+#endif
 static char    *ibm_ids[] = {"IBM0068", "LEN0068", "LEN0268", NULL};
 
 static int
@@ -482,6 +494,20 @@ acpi_ibm_attach(device_t dev)
 	}
 	sc->ec_handle = acpi_get_handle(sc->ec_dev);
 
+#ifdef EVDEV_SUPPORT
+	sc->evdev = evdev_alloc();
+	evdev_set_name(sc->evdev, device_get_desc(dev));
+	evdev_set_phys(sc->evdev, device_get_nameunit(dev));
+	evdev_set_id(sc->evdev, BUS_HOST, 0, 0, 1);
+	evdev_support_event(sc->evdev, EV_SYN);
+	evdev_support_event(sc->evdev, EV_KEY);
+	evdev_support_key(sc->evdev, KEY_BRIGHTNESSUP);
+	evdev_support_key(sc->evdev, KEY_BRIGHTNESSDOWN);
+
+	if (evdev_register(sc->evdev) != 0)
+		return (ENXIO);
+#endif
+
 	/* Get the sysctl tree */
 	sc->sysctl_ctx = device_get_sysctl_ctx(dev);
 	sc->sysctl_tree = device_get_sysctl_tree(dev);
@@ -627,6 +653,10 @@ acpi_ibm_detach(device_t dev)
 	if (sc->led_dev != NULL)
 		led_destroy(sc->led_dev);
 
+#ifdef EVDEV_SUPPORT
+	evdev_free(sc->evdev);
+#endif
+
 	return (0);
 }
 
@@ -1499,6 +1529,19 @@ acpi_ibm_notify(ACPI_HANDLE h, UINT32 notify, void *context)
 			/* Execute event handler */
 			if (sc->handler_events & (1 << (arg - 1)))
 				acpi_ibm_eventhandler(sc, (arg & 0xff));
+#ifdef EVDEV_SUPPORT
+			else if ((arg & 0xff) == IBM_EVENT_BRIGHTNESS_UP ||
+			    (arg & 0xff) == IBM_EVENT_BRIGHTNESS_DOWN) {
+				uint16_t key;
+
+				key = arg == IBM_EVENT_BRIGHTNESS_UP ?
+				    KEY_BRIGHTNESSUP : KEY_BRIGHTNESSDOWN;
+				evdev_push_key(sc->evdev, key, 1);
+				evdev_sync(sc->evdev);
+				evdev_push_key(sc->evdev, key, 0);
+				evdev_sync(sc->evdev);
+			}
+#endif
 
 			/* Notify devd(8) */
 			acpi_UserNotify("IBM", h, (arg & 0xff));

sys/modules/acpi/acpi_ibm/Makefile

@@ -1,6 +1,6 @@
 .PATH:		${SRCTOP}/sys/dev/acpi_support
 KMOD=		acpi_ibm
 SRCS=		acpi_ibm.c opt_acpi.h device_if.h bus_if.h acpi_if.h
-SRCS+=		opt_ddb.h
+SRCS+=		opt_ddb.h opt_evdev.h
 
 .include <bsd.kmod.mk>