FreeBSD-10+ patch to enable ACPI CMOS regions

Index: sys/x86/isa/atrtc.c
===================================================================
--- sys/x86/isa/atrtc.c (revision 267519)
+++ sys/x86/isa/atrtc.c (working copy)
@@ -31,6 +31,7 @@
 __FBSDID("$FreeBSD$");

 #include "opt_isa.h"
+#include "opt_acpi.h"

 #include <sys/param.h>
 #include <sys/systm.h>
@@ -53,6 +54,10 @@
 #include <machine/intr_machdep.h>
 #include "clock_if.h"

+#include <contrib/dev/acpica/include/acpi.h>
+#include <contrib/dev/acpica/include/accommon.h>
+#include <dev/acpica/acpivar.h>
+
 #define    RTC_LOCK    do { if (!kdb_active) mtx_lock_spin(&clock_lock); } while (0)
 #define    RTC_UNLOCK  do { if (!kdb_active) mtx_unlock_spin(&clock_lock); } while (0)

@@ -161,8 +166,33 @@
    struct resource *intr_res;
    void *intr_handler;
    struct eventtimer et;
+   ACPI_HANDLE acpi_handle;    /* Handle of the PNP0B00 node */
 };

+static ACPI_STATUS
+acpi_rtc_cmos_handler(UINT32 function, ACPI_PHYSICAL_ADDRESS address, UINT32 width,
+               UINT64 *value, void *context, void *region_context)
+{
+   struct atrtc_softc *sc;
+
+   sc = (struct atrtc_softc *)context;
+   if (!value || !sc)
+       return AE_BAD_PARAMETER;
+   if (width != 8 || address >= 64U)
+       return AE_BAD_PARAMETER;
+   switch (function) {
+       case ACPI_READ:
+           *((UINT8 *)value) = rtcin((int)address);
+           break;
+       case ACPI_WRITE:
+           writertc((int)address, *((UINT8 *)value));
+           break;
+       default:
+           return AE_BAD_PARAMETER;
+   }
+   return AE_OK;
+}
+
 static int
 rtc_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
 {
@@ -245,10 +275,17 @@
    int i;

    sc = device_get_softc(dev);
+   sc->acpi_handle = acpi_get_handle(dev);
    sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid,
        IO_RTC, IO_RTC + 1, 2, RF_ACTIVE);
    if (sc->port_res == NULL)
        device_printf(dev, "Warning: Couldn't map I/O.\n");
+   if (ACPI_FAILURE(AcpiInstallAddressSpaceHandler(sc->acpi_handle,
+                       ACPI_ADR_SPACE_CMOS, acpi_rtc_cmos_handler, NULL, sc)))
+   {
+       device_printf(dev, "Error registering ACPI CMOS address space handler.\n");
+       return 0;
+   }
    atrtc_start();
    clock_register(dev, 1000000);
    bzero(&sc->et, sizeof(struct eventtimer));
@@ -286,6 +323,15 @@
    return(0);
 }

+static int atrtc_detach(device_t dev)
+{
+   struct atrtc_softc *sc;
+
+   sc = device_get_softc(dev);
+   AcpiRemoveAddressSpaceHandler(sc->acpi_handle, ACPI_ADR_SPACE_CMOS, acpi_rtc_cmos_handler);
+   return bus_generic_detach(dev);
+}
+
 static int
 atrtc_resume(device_t dev)
 {
@@ -366,7 +412,7 @@
    /* Device interface */
    DEVMETHOD(device_probe,     atrtc_probe),
    DEVMETHOD(device_attach,    atrtc_attach),
-   DEVMETHOD(device_detach,    bus_generic_detach),
+   DEVMETHOD(device_detach,    atrtc_detach),
    DEVMETHOD(device_shutdown,  bus_generic_shutdown),
    DEVMETHOD(device_suspend,   bus_generic_suspend),
        /* XXX stop statclock? */
@@ -402,3 +448,4 @@
        rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
 }
 #endif /* DDB */
+