fdt: Add support for simple-mfd bus

Quoting the binding Documentation :

"These devices comprise a nexus for heterogeneous hardware blocks containing
more than one non-unique yet varying hardware functionality."

Reviewed by:	loos
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D17751

sys/conf/files

@@ -1762,6 +1762,7 @@ dev/fdt/fdt_slicer.c		optional fdt cfi | fdt nand | fdt mx25l | fdt n25q
 dev/fdt/fdt_static_dtb.S	optional fdt fdt_dtb_static \
 	dependency	"fdt_dtb_file"
 dev/fdt/simplebus.c		optional fdt
+dev/fdt/simple_mfd.c		optional fdt
 dev/fe/if_fe.c			optional fe
 dev/fe/if_fe_pccard.c		optional fe pccard
 dev/filemon/filemon.c		optional filemon

sys/dev/fdt/simple_mfd.c

@@ -0,0 +1,176 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2018 Rubicon Communications, LLC (Netgate)
+ *
+ * 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/systm.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+
+#include <machine/bus.h>
+
+#include <dev/fdt/simplebus.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+struct simple_mfd_softc {
+	struct simplebus_softc	sc;
+};
+
+device_t simple_mfd_add_device(device_t dev, phandle_t node, u_int order,
+    const char *name, int unit, struct simplebus_devinfo *di);
+struct simplebus_devinfo *simple_mfd_setup_dinfo(device_t dev, phandle_t node, struct simplebus_devinfo *di);
+
+static int
+simple_mfd_probe(device_t dev)
+{
+
+	if (!ofw_bus_status_okay(dev))
+		return (ENXIO);
+	if (!ofw_bus_is_compatible(dev, "simple-mfd"))
+		return (ENXIO);
+
+	device_set_desc(dev, "Simple MFD (Multi-Functions Device)");
+
+	return (BUS_PROBE_GENERIC);
+}
+
+static int
+simple_mfd_attach(device_t dev)
+{
+	struct simple_mfd_softc *sc;
+	phandle_t node, child;
+	device_t cdev;
+
+	sc = device_get_softc(dev);
+	node = ofw_bus_get_node(dev);
+
+	/* Parse address-cells and size-cells from the parent node as a fallback */
+	if (OF_getencprop(node, "#address-cells", &sc->sc.acells,
+	    sizeof(sc->sc.acells)) == -1) {
+		if (OF_getencprop(OF_parent(node), "#address-cells", &sc->sc.acells,
+		    sizeof(sc->sc.acells)) == -1) {
+			sc->sc.acells = 2;
+		}
+	}
+	if (OF_getencprop(node, "#size-cells", &sc->sc.scells,
+	    sizeof(sc->sc.scells)) == -1) {
+		if (OF_getencprop(OF_parent(node), "#size-cells", &sc->sc.scells,
+		    sizeof(sc->sc.scells)) == -1) {
+			sc->sc.scells = 1;
+		}
+	}
+
+	/* If the node has a ranges prop, parse it so children mapping will be done correctly */
+	if (OF_hasprop(node, "ranges")) {
+		if (simplebus_fill_ranges(node, &sc->sc) < 0) {
+			device_printf(dev, "could not get ranges\n");
+			return (ENXIO);
+		}
+	}
+
+	/* Attach child devices */
+	for (child = OF_child(node); child > 0; child = OF_peer(child)) {
+		cdev = simple_mfd_add_device(dev, child, 0, NULL, -1, NULL);
+		if (cdev != NULL)
+			device_probe_and_attach(cdev);
+	}
+
+	return (bus_generic_attach(dev));
+}
+
+struct simplebus_devinfo *
+simple_mfd_setup_dinfo(device_t dev, phandle_t node,
+    struct simplebus_devinfo *di)
+{
+	struct simplebus_softc *sc;
+	struct simplebus_devinfo *ndi;
+
+	sc = device_get_softc(dev);
+	if (di == NULL)
+		ndi = malloc(sizeof(*ndi), M_DEVBUF, M_WAITOK | M_ZERO);
+	else
+		ndi = di;
+	if (ofw_bus_gen_setup_devinfo(&ndi->obdinfo, node) != 0) {
+		if (di == NULL)
+			free(ndi, M_DEVBUF);
+		return (NULL);
+	}
+
+	/* reg resources is from the parent but interrupts is on the node itself */
+	resource_list_init(&ndi->rl);
+	ofw_bus_reg_to_rl(dev, OF_parent(node), sc->acells, sc->scells, &ndi->rl);
+	ofw_bus_intr_to_rl(dev, node, &ndi->rl, NULL);
+
+	return (ndi);
+}
+
+device_t
+simple_mfd_add_device(device_t dev, phandle_t node, u_int order,
+    const char *name, int unit, struct simplebus_devinfo *di)
+{
+	struct simplebus_devinfo *ndi;
+	device_t cdev;
+
+	if ((ndi = simple_mfd_setup_dinfo(dev, node, di)) == NULL)
+		return (NULL);
+	cdev = device_add_child_ordered(dev, order, name, unit);
+	if (cdev == NULL) {
+		device_printf(dev, "<%s>: device_add_child failed\n",
+		    ndi->obdinfo.obd_name);
+		resource_list_free(&ndi->rl);
+		ofw_bus_gen_destroy_devinfo(&ndi->obdinfo);
+		if (di == NULL)
+			free(ndi, M_DEVBUF);
+		return (NULL);
+	}
+	device_set_ivars(cdev, ndi);
+
+	return(cdev);
+}
+
+static device_method_t simple_mfd_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		simple_mfd_probe),
+	DEVMETHOD(device_attach,	simple_mfd_attach),
+
+	DEVMETHOD_END
+};
+
+DEFINE_CLASS_1(simple_mfd, simple_mfd_driver, simple_mfd_methods,
+  sizeof(struct simple_mfd_softc), simplebus_driver);
+
+static devclass_t simple_mfd_devclass;
+
+EARLY_DRIVER_MODULE(simple_mfd, simplebus, simple_mfd_driver,
+    simple_mfd_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_LATE);
+MODULE_VERSION(simple_mfd, 1);

sys/dev/fdt/simplebus.c

@@ -61,13 +61,6 @@ static struct resource_list *simplebus_get_resource_list(device_t bus,
 static const struct ofw_bus_devinfo *simplebus_get_devinfo(device_t bus,
     device_t child);
 
-/*
- * local methods
- */
-
-static int simplebus_fill_ranges(phandle_t node,
-    struct simplebus_softc *sc);
-
 /*
  * Driver methods.
  */
@@ -184,7 +177,7 @@ simplebus_init(device_t dev, phandle_t node)
 	OF_getencprop(node, "#size-cells", &sc->scells, sizeof(sc->scells));
 }
 
-static int
+int
 simplebus_fill_ranges(phandle_t node, struct simplebus_softc *sc)
 {
 	int host_address_cells;

sys/dev/fdt/simplebus.h

@@ -61,4 +61,6 @@ device_t simplebus_add_device(device_t dev, phandle_t node, u_int order,
     const char *name, int unit, struct simplebus_devinfo *di);
 struct simplebus_devinfo *simplebus_setup_dinfo(device_t dev, phandle_t node,
     struct simplebus_devinfo *di);
+int simplebus_fill_ranges(phandle_t node,
+    struct simplebus_softc *sc);
 #endif	/* _FDT_SIMPLEBUS_H */