Initial implementation of the OFW i/f methods for FDT back-end.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation

sys/dev/ofw/ofw_fdt.c

@@ -0,0 +1,458 @@
+/*-
+ * Copyright (c) 2009-2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Semihalf under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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/malloc.h>
+#include <sys/systm.h>
+
+#include <contrib/libfdt/libfdt.h>
+
+#include <machine/stdarg.h>
+
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/ofwvar.h>
+#include <dev/ofw/openfirm.h>
+
+#include "ofw_if.h"
+
+#ifdef DEBUG
+#define debugf(fmt, args...) do { printf("%s(): ", __func__);	\
+    printf(fmt,##args); } while (0)
+#else
+#define debugf(fmt, args...)
+#endif
+
+static int ofw_fdt_init(ofw_t, void *);
+static phandle_t ofw_fdt_peer(ofw_t, phandle_t);
+static phandle_t ofw_fdt_child(ofw_t, phandle_t);
+static phandle_t ofw_fdt_parent(ofw_t, phandle_t);
+static phandle_t ofw_fdt_instance_to_package(ofw_t, ihandle_t);
+static ssize_t ofw_fdt_getproplen(ofw_t, phandle_t, const char *);
+static ssize_t ofw_fdt_getprop(ofw_t, phandle_t, const char *, void *, size_t);
+static int ofw_fdt_nextprop(ofw_t, phandle_t, const char *, char *, size_t);
+static int ofw_fdt_setprop(ofw_t, phandle_t, const char *, const void *,
+    size_t);
+static ssize_t ofw_fdt_canon(ofw_t, const char *, char *, size_t);
+static phandle_t ofw_fdt_finddevice(ofw_t, const char *);
+static ssize_t ofw_fdt_instance_to_path(ofw_t, ihandle_t, char *, size_t);
+static ssize_t ofw_fdt_package_to_path(ofw_t, phandle_t, char *, size_t);
+static int ofw_fdt_interpret(ofw_t, const char *, int, unsigned long *);
+
+static ofw_method_t ofw_fdt_methods[] = {
+	OFWMETHOD(ofw_init,			ofw_fdt_init),
+	OFWMETHOD(ofw_peer,			ofw_fdt_peer),
+	OFWMETHOD(ofw_child,			ofw_fdt_child),
+	OFWMETHOD(ofw_parent,			ofw_fdt_parent),
+	OFWMETHOD(ofw_instance_to_package,	ofw_fdt_instance_to_package),
+	OFWMETHOD(ofw_getproplen,		ofw_fdt_getproplen),
+	OFWMETHOD(ofw_getprop,			ofw_fdt_getprop),
+	OFWMETHOD(ofw_nextprop,			ofw_fdt_nextprop),
+	OFWMETHOD(ofw_setprop,			ofw_fdt_setprop),
+	OFWMETHOD(ofw_canon,			ofw_fdt_canon),
+	OFWMETHOD(ofw_finddevice,		ofw_fdt_finddevice),
+	OFWMETHOD(ofw_instance_to_path,		ofw_fdt_instance_to_path),
+	OFWMETHOD(ofw_package_to_path,		ofw_fdt_package_to_path),
+	OFWMETHOD(ofw_interpret,		ofw_fdt_interpret),
+	{ 0, 0 }
+};
+
+static ofw_def_t ofw_fdt = {
+	OFW_FDT,
+	ofw_fdt_methods,
+	0
+};
+OFW_DEF(ofw_fdt);
+
+static void *fdtp = NULL;
+
+static int
+ofw_fdt_init(ofw_t ofw, void *data)
+{
+	int err;
+
+	/* Check FDT blob integrity */
+	if ((err = fdt_check_header(data)) != 0)
+		return (err);
+
+	fdtp = data;
+	return (0);
+}
+
+/*
+ * Device tree functions
+ */
+
+static int
+fdt_phandle_offset(phandle_t p)
+{
+	const char *dt_struct;
+	int offset;
+
+	dt_struct = (const char *)fdtp + fdt_off_dt_struct(fdtp);
+
+	if (((const char *)p < dt_struct) ||
+	    (const char *)p > (dt_struct + fdt_size_dt_struct(fdtp)))
+		return (-1);
+
+	offset = (const char *)p - dt_struct;
+	if (offset < 0)
+		return (-1);
+
+	return (offset);
+}
+
+/* Return the next sibling of this node or 0. */
+static phandle_t
+ofw_fdt_peer(ofw_t ofw, phandle_t node)
+{
+	phandle_t p;
+	int depth, offset;
+
+	if (node == 0) {
+		/* Find root node */
+		offset = fdt_path_offset(fdtp, "/");
+		p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
+
+		return (p);
+	}
+
+	offset = fdt_phandle_offset(node);
+	if (offset < 0)
+		return (0);
+
+	for (depth = 1, offset = fdt_next_node(fdtp, offset, &depth);
+	    offset >= 0;
+	    offset = fdt_next_node(fdtp, offset, &depth)) {
+		if (depth < 0)
+			return (0);
+		if (depth == 1) {
+			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
+			return (p);
+		}
+	}
+
+	return (0);
+}
+
+/* Return the first child of this node or 0. */
+static phandle_t
+ofw_fdt_child(ofw_t ofw, phandle_t node)
+{
+	phandle_t p;
+	int depth, offset;
+
+	offset = fdt_phandle_offset(node);
+	if (offset < 0)
+		return (0);
+
+	for (depth = 0, offset = fdt_next_node(fdtp, offset, &depth);
+	    (offset >= 0) && (depth > 0);
+	    offset = fdt_next_node(fdtp, offset, &depth)) {
+		if (depth < 0)
+			return (0);
+		if (depth == 1) {
+			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
+			return (p);
+		}
+	}
+
+	return (0);
+}
+
+/* Return the parent of this node or 0. */
+static phandle_t
+ofw_fdt_parent(ofw_t ofw, phandle_t node)
+{
+	phandle_t p;
+	int offset, paroffset;
+
+	offset = fdt_phandle_offset(node);
+	if (offset < 0)
+		return (0);
+
+	paroffset = fdt_parent_offset(fdtp, offset);
+	p = (phandle_t)fdt_offset_ptr(fdtp, paroffset, sizeof(phandle_t));
+	return (p);
+}
+
+/* Return the package handle that corresponds to an instance handle. */
+static phandle_t
+ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
+{
+	phandle_t p;
+	int offset;
+
+	/*
+	 * Note: FDT does not have the notion of instances, but we somewhat
+	 * abuse the semantics and let treat as 'instance' the internal
+	 * 'phandle' prop, so that ofw I/F consumers have a uniform way of
+	 * translation between internal representation (which appear in some
+	 * contexts as property values) and effective phandles.
+	 */
+	offset = fdt_node_offset_by_phandle(fdtp, instance);
+	if (offset < 0)
+		return (0);
+
+	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(phandle_t));
+	return (p);
+}
+
+/* Get the length of a property of a package. */
+static ssize_t
+ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
+{
+	const struct fdt_property *prop;
+	int offset, len;
+
+	offset = fdt_phandle_offset(package);
+	if (offset < 0)
+		return (0);
+
+	if (strcmp(propname, "name") == 0) {
+		/* Emulate the 'name' property */
+		fdt_get_name(fdtp, offset, &len);
+		return (len + 1);
+	}
+
+	len = 0;
+	prop = fdt_get_property(fdtp, offset, propname, &len);
+
+	return (len);
+}
+
+/* Get the value of a property of a package. */
+static ssize_t
+ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
+    size_t buflen)
+{
+	const void *prop;
+	const char *name;
+	int len, offset;
+
+	offset = fdt_phandle_offset(package);
+	if (offset < 0)
+		return (0);
+
+	if (strcmp(propname, "name") == 0) {
+		/* Emulate the 'name' property */
+		name = fdt_get_name(fdtp, offset, &len);
+		strncpy(buf, name, buflen);
+		if (len + 1 > buflen)
+			len = buflen;
+		return (len + 1);
+	}
+
+	prop = fdt_getprop(fdtp, offset, propname, &len);
+	if (prop == NULL)
+		return (0);
+
+	if (len > buflen)
+		len = buflen;
+	bcopy(prop, buf, len);
+	return (len);
+}
+
+static int
+fdt_nextprop(int offset, char *buf, size_t size)
+{
+	const struct fdt_property *prop;
+	const char *name;
+	uint32_t tag;
+	int nextoffset, depth;
+
+	depth = 0;
+	tag = fdt_next_tag(fdtp, offset, &nextoffset);
+
+	/* Find the next prop */
+	do {
+		offset = nextoffset;
+		tag = fdt_next_tag(fdtp, offset, &nextoffset);
+
+		if (tag == FDT_BEGIN_NODE)
+			depth++;
+		else if (tag == FDT_END_NODE)
+			depth--;
+		else if ((tag == FDT_PROP) && (depth == 0)) {
+			prop =
+			    (const struct fdt_property *)fdt_offset_ptr(fdtp,
+			    offset, sizeof(*prop));
+			name = fdt_string(fdtp,
+			    fdt32_to_cpu(prop->nameoff));
+			strncpy(buf, name, size);
+			return (strlen(name));
+		} else
+			depth = -1;
+	} while (depth >= 0);
+
+	return (0);
+}
+
+/*
+ * Get the next property of a package. Return the actual len of retrieved
+ * prop name.
+ */
+static int
+ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
+    size_t size)
+{
+	const struct fdt_property *prop;
+	int offset, rv;
+
+	offset = fdt_phandle_offset(package);
+	if (offset < 0)
+		return (0);
+
+	if (previous == NULL)
+		/* Find the first prop in the node */
+		return (fdt_nextprop(offset, buf, size));
+
+	/*
+	 * Advance to the previous prop
+	 */
+	prop = fdt_get_property(fdtp, offset, previous, NULL);
+	if (prop == NULL)
+		return (0);
+
+	offset = fdt_phandle_offset((phandle_t)prop);
+	rv = fdt_nextprop(offset, buf, size);
+	return (rv);
+}
+
+/* Set the value of a property of a package. */
+static int
+ofw_fdt_setprop(ofw_t ofw, phandle_t package, const char *propname,
+    const void *buf, size_t len)
+{
+	int offset;
+
+	offset = fdt_phandle_offset(package);
+	if (offset < 0)
+		return (-1);
+
+	return (fdt_setprop_inplace(fdtp, offset, propname, buf, len));
+}
+
+/* Convert a device specifier to a fully qualified pathname. */
+static ssize_t
+ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
+{
+
+	return (-1);
+}
+
+/* Return a package handle for the specified device. */
+static phandle_t
+ofw_fdt_finddevice(ofw_t ofw, const char *device)
+{
+	phandle_t p;
+	int offset;
+
+	offset = fdt_path_offset(fdtp, device);
+
+	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
+
+	return (p);
+}
+
+/* Return the fully qualified pathname corresponding to an instance. */
+static ssize_t
+ofw_fdt_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
+{
+
+	return (-1);
+}
+
+/* Return the fully qualified pathname corresponding to a package. */
+static ssize_t
+ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
+{
+
+	return (-1);
+}
+
+static int
+ofw_fdt_fixup(ofw_t ofw)
+{
+#define FDT_MODEL_LEN	80
+	char model[FDT_MODEL_LEN];
+	phandle_t root;
+	ssize_t len;
+	int i;
+
+	if ((root = ofw_fdt_finddevice(ofw, "/")) == 0)
+		return (ENODEV);
+
+	if ((len = ofw_fdt_getproplen(ofw, root, "model")) <= 0)
+		return (0);
+
+	bzero(model, FDT_MODEL_LEN);
+	if (ofw_fdt_getprop(ofw, root, "model", model, FDT_MODEL_LEN) <= 0)
+		return (0);
+
+	/*
+	 * Search fixup table and call handler if appropriate.
+	 */
+	for (i = 0; fdt_fixup_table[i].model != NULL; i++) {
+		if (strncmp(model, fdt_fixup_table[i].model,
+		    FDT_MODEL_LEN) != 0)
+			continue;
+
+		if (fdt_fixup_table[i].handler != NULL)
+			(*fdt_fixup_table[i].handler)(root);
+	}
+
+	return (0);
+}
+
+static int
+ofw_fdt_interpret(ofw_t ofw, const char *cmd, int nret, unsigned long *retvals)
+{
+	int rv;
+
+	/*
+	 * Note: FDT does not have the possibility to 'interpret' commands,
+	 * but we abuse the interface a bit to use it for doing non-standard
+	 * operations on the device tree blob.
+	 *
+	 * Currently the only supported 'command' is to trigger performing
+	 * fixups.
+	 */
+	if (strncmp("perform-fixup", cmd, 13) != 0)
+		return (0);
+
+	rv = ofw_fdt_fixup(ofw);
+	if (nret > 0)
+		retvals[0] = rv;
+
+	return (rv);
+}