/*
 * Procedures for creating, accessing and interpreting the device tree.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 * 
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com 
 *
 *  Adapted for sparc32 by David S. Miller davem@davemloft.net
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/module.h>

#include <asm/prom.h>
#include <asm/oplib.h>

#include "prom.h"

static unsigned int prom_early_allocated;

void * __init prom_early_alloc(unsigned long size)
{
	void *ret;

	ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
	if (ret != NULL)
		memset(ret, 0, size);

	prom_early_allocated += size;

	return ret;
}

static int is_root_node(const struct device_node *dp)
{
	if (!dp)
		return 0;

	return (dp->parent == NULL);
}

/* The following routines deal with the black magic of fully naming a
 * node.
 *
 * Certain well known named nodes are just the simple name string.
 *
 * Actual devices have an address specifier appended to the base name
 * string, like this "foo@addr".  The "addr" can be in any number of
 * formats, and the platform plus the type of the node determine the
 * format and how it is constructed.
 *
 * For children of the ROOT node, the naming convention is fixed and
 * determined by whether this is a sun4u or sun4v system.
 *
 * For children of other nodes, it is bus type specific.  So
 * we walk up the tree until we discover a "device_type" property
 * we recognize and we go from there.
 */
static void __init sparc32_path_component(struct device_node *dp, char *tmp_buf)
{
	struct linux_prom_registers *regs;
	struct property *rprop;

	rprop = of_find_property(dp, "reg", NULL);
	if (!rprop)
		return;

	regs = rprop->value;
	sprintf(tmp_buf, "%s@%x,%x",
		dp->name,
		regs->which_io, regs->phys_addr);
}

/* "name@slot,offset"  */
static void __init sbus_path_component(struct device_node *dp, char *tmp_buf)
{
	struct linux_prom_registers *regs;
	struct property *prop;

	prop = of_find_property(dp, "reg", NULL);
	if (!prop)
		return;

	regs = prop->value;
	sprintf(tmp_buf, "%s@%x,%x",
		dp->name,
		regs->which_io,
		regs->phys_addr);
}

/* "name@devnum[,func]" */
static void __init pci_path_component(struct device_node *dp, char *tmp_buf)
{
	struct linux_prom_pci_registers *regs;
	struct property *prop;
	unsigned int devfn;

	prop = of_find_property(dp, "reg", NULL);
	if (!prop)
		return;

	regs = prop->value;
	devfn = (regs->phys_hi >> 8) & 0xff;
	if (devfn & 0x07) {
		sprintf(tmp_buf, "%s@%x,%x",
			dp->name,
			devfn >> 3,
			devfn & 0x07);
	} else {
		sprintf(tmp_buf, "%s@%x",
			dp->name,
			devfn >> 3);
	}
}

/* "name@addrhi,addrlo" */
static void __init ebus_path_component(struct device_node *dp, char *tmp_buf)
{
	struct linux_prom_registers *regs;
	struct property *prop;

	prop = of_find_property(dp, "reg", NULL);
	if (!prop)
		return;

	regs = prop->value;

	sprintf(tmp_buf, "%s@%x,%x",
		dp->name,
		regs->which_io, regs->phys_addr);
}

static void __init __build_path_component(struct device_node *dp, char *tmp_buf)
{
	struct device_node *parent = dp->parent;

	if (parent != NULL) {
		if (!strcmp(parent->type, "pci") ||
		    !strcmp(parent->type, "pciex"))
			return pci_path_component(dp, tmp_buf);
		if (!strcmp(parent->type, "sbus"))
			return sbus_path_component(dp, tmp_buf);
		if (!strcmp(parent->type, "ebus"))
			return ebus_path_component(dp, tmp_buf);

		/* "isa" is handled with platform naming */
	}

	/* Use platform naming convention.  */
	return sparc32_path_component(dp, tmp_buf);
}

static char * __init build_path_component(struct device_node *dp)
{
	char tmp_buf[64], *n;

	tmp_buf[0] = '\0';
	__build_path_component(dp, tmp_buf);
	if (tmp_buf[0] == '\0')
		strcpy(tmp_buf, dp->name);

	n = prom_early_alloc(strlen(tmp_buf) + 1);
	strcpy(n, tmp_buf);

	return n;
}

static char * __init build_full_name(struct device_node *dp)
{
	int len, ourlen, plen;
	char *n;

	plen = strlen(dp->parent->full_name);
	ourlen = strlen(dp->path_component_name);
	len = ourlen + plen + 2;

	n = prom_early_alloc(len);
	strcpy(n, dp->parent->full_name);
	if (!is_root_node(dp->parent)) {
		strcpy(n + plen, "/");
		plen++;
	}
	strcpy(n + plen, dp->path_component_name);

	return n;
}

static char * __init get_one_property(phandle node, char *name)
{
	char *buf = "<NULL>";
	int len;

	len = prom_getproplen(node, name);
	if (len > 0) {
		buf = prom_early_alloc(len);
		len = prom_getproperty(node, name, buf, len);
	}

	return buf;
}

static struct device_node * __init create_node(phandle node)
{
	struct device_node *dp;

	if (!node)
		return NULL;

	dp = prom_early_alloc(sizeof(*dp));
	dp->unique_id = prom_unique_id++;

	kref_init(&dp->kref);

	dp->name = get_one_property(node, "name");
	dp->type = get_one_property(node, "device_type");
	dp->node = node;

	/* Build interrupts later... */

	dp->properties = build_prop_list(node);

	return dp;
}

static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
{
	struct device_node *dp;

	dp = create_node(node);
	if (dp) {
		*(*nextp) = dp;
		*nextp = &dp->allnext;

		dp->parent = parent;
		dp->path_component_name = build_path_component(dp);
		dp->full_name = build_full_name(dp);

		dp->child = build_tree(dp, prom_getchild(node), nextp);

		dp->sibling = build_tree(parent, prom_getsibling(node), nextp);
	}

	return dp;
}

struct device_node *of_console_device;
EXPORT_SYMBOL(of_console_device);

char *of_console_path;
EXPORT_SYMBOL(of_console_path);

char *of_console_options;
EXPORT_SYMBOL(of_console_options);

extern void restore_current(void);

static void __init of_console_init(void)
{
	char *msg = "OF stdout device is: %s\n";
	struct device_node *dp;
	unsigned long flags;
	const char *type;
	phandle node;
	int skip, tmp, fd;

	of_console_path = prom_early_alloc(256);

	switch (prom_vers) {
	case PROM_V0:
		skip = 0;
		switch (*romvec->pv_stdout) {
		case PROMDEV_SCREEN:
			type = "display";
			break;

		case PROMDEV_TTYB:
			skip = 1;
			/* FALLTHRU */

		case PROMDEV_TTYA:
			type = "serial";
			break;

		default:
			prom_printf("Invalid PROM_V0 stdout value %u\n",
				    *romvec->pv_stdout);
			prom_halt();
		}

		tmp = skip;
		for_each_node_by_type(dp, type) {
			if (!tmp--)
				break;
		}
		if (!dp) {
			prom_printf("Cannot find PROM_V0 console node.\n");
			prom_halt();
		}
		of_console_device = dp;

		strcpy(of_console_path, dp->full_name);
		if (!strcmp(type, "serial")) {
			strcat(of_console_path,
			       (skip ? ":b" : ":a"));
		}
		break;

	default:
	case PROM_V2:
	case PROM_V3:
		fd = *romvec->pv_v2bootargs.fd_stdout;

		spin_lock_irqsave(&prom_lock, flags);
		node = (*romvec->pv_v2devops.v2_inst2pkg)(fd);
		restore_current();
		spin_unlock_irqrestore(&prom_lock, flags);

		if (!node) {
			prom_printf("Cannot resolve stdout node from "
				    "instance %08x.\n", fd);
			prom_halt();
		}
		dp = of_find_node_by_phandle(node);
		type = of_get_property(dp, "device_type", NULL);

		if (!type) {
			prom_printf("Console stdout lacks "
				    "device_type property.\n");
			prom_halt();
		}

		if (strcmp(type, "display") && strcmp(type, "serial")) {
			prom_printf("Console device_type is neither display "
				    "nor serial.\n");
			prom_halt();
		}

		of_console_device = dp;

		if (prom_vers == PROM_V2) {
			strcpy(of_console_path, dp->full_name);
			switch (*romvec->pv_stdout) {
			case PROMDEV_TTYA:
				strcat(of_console_path, ":a");
				break;
			case PROMDEV_TTYB:
				strcat(of_console_path, ":b");
				break;
			}
		} else {
			const char *path;

			dp = of_find_node_by_path("/");
			path = of_get_property(dp, "stdout-path", NULL);
			if (!path) {
				prom_printf("No stdout-path in root node.\n");
				prom_halt();
			}
			strcpy(of_console_path, path);
		}
		break;
	}

	of_console_options = strrchr(of_console_path, ':');
	if (of_console_options) {
		of_console_options++;
		if (*of_console_options == '\0')
			of_console_options = NULL;
	}

	prom_printf(msg, of_console_path);
	printk(msg, of_console_path);
}

void __init prom_build_devicetree(void)
{
	struct device_node **nextp;

	allnodes = create_node(prom_root_node);
	allnodes->path_component_name = "";
	allnodes->full_name = "/";

	nextp = &allnodes->allnext;
	allnodes->child = build_tree(allnodes,
				     prom_getchild(allnodes->node),
				     &nextp);
	of_console_init();

	printk("PROM: Built device tree with %u bytes of memory.\n",
	       prom_early_allocated);
}