Add support for the DesignWare MMC hardware in the HiSilicon hi6220. This

SoC is used in the HiKey board from 96boards.

Currently on the SD card is working on the HiKey, as such devices 0 and 2
will need to be disabled, for example by adding the following to
loader.conf:

hint.hisi_dwmmc.0.disabled=1
hint.hisi_dwmmc.2.disabled=1

Relnotes:	yes (Hikey board booting)
Sponsored by:	ABT Systems Ltd

sys/arm64/conf/GENERIC

@@ -107,6 +107,11 @@ device		ahci
 device		scbus
 device		da
 
+# MMC/SD/SDIO Card slot support
+device		mmc			# mmc/sd bus
+device		mmcsd			# mmc/sd flash cards
+device		dwmmc
+
 # Serial (COM) ports
 device		uart		# Generic UART driver
 device		pl011

sys/conf/files.arm64

@@ -59,6 +59,8 @@ dev/acpica/acpi_if.m		optional	acpi
 dev/fdt/fdt_arm64.c		optional	fdt
 dev/hwpmc/hwpmc_arm64.c		optional	hwpmc
 dev/hwpmc/hwpmc_arm64_md.c	optional	hwpmc
+dev/mmc/host/dwmmc.c		optional	dwmmc
+dev/mmc/host/dwmmc_hisi.c	optional	dwmmc soc_hisi_hi6220
 dev/ofw/ofw_cpu.c		optional	fdt
 dev/pci/pci_host_generic.c	optional	pci fdt
 dev/psci/psci.c			optional	psci

sys/dev/mmc/host/dwmmc_hisi.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2015 Andrew Turner.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/bus.h>
+#include <sys/module.h>
+
+#include <machine/bus.h>
+
+#include <dev/mmc/bridge.h>
+
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <dev/mmc/host/dwmmc_var.h>
+
+static device_probe_t hisi_dwmmc_probe;
+static device_attach_t hisi_dwmmc_attach;
+
+static int
+hisi_dwmmc_probe(device_t dev)
+{
+
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+
+	if (!ofw_bus_is_compatible(dev, "hisilicon,hi6220-dw-mshc"))
+		return (ENXIO);
+
+	device_set_desc(dev, "Synopsys DesignWare Mobile "
+	    "Storage Host Controller (HiSilicon)");
+
+	return (BUS_PROBE_VENDOR);
+}
+
+static int
+hisi_dwmmc_attach(device_t dev)
+{
+	struct dwmmc_softc *sc;
+
+	sc = device_get_softc(dev);
+	sc->hwtype = HWTYPE_HISILICON;
+	/* TODO: Calculate this from a clock driver */
+	sc->bus_hz = 24000000; /* 24MHz */
+
+	/*
+	 * ARM64TODO: This is likely because we lack support for
+	 * DMA when the controller is not cache-coherent on arm64.
+	 */
+	sc->use_pio = 1;
+	sc->desc_count = 1;
+
+	return (dwmmc_attach(dev));
+}
+
+static device_method_t hisi_dwmmc_methods[] = {
+	/* bus interface */
+	DEVMETHOD(device_probe, hisi_dwmmc_probe),
+	DEVMETHOD(device_attach, hisi_dwmmc_attach),
+
+	DEVMETHOD_END
+};
+
+static devclass_t hisi_dwmmc_devclass;
+
+DEFINE_CLASS_1(hisi_dwmmc, hisi_dwmmc_driver, hisi_dwmmc_methods,
+    sizeof(struct dwmmc_softc), dwmmc_driver);
+DRIVER_MODULE(hisi_dwmmc, simplebus, hisi_dwmmc_driver,
+    hisi_dwmmc_devclass, 0, 0);