aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sparc/kernel/devices.c
blob: 3d465e87f7e247db101d757fff4abbfeac9b3719 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/* devices.c: Initial scan of the prom device tree for important
 *	      Sparc device nodes which we need to find.
 *
 * This is based on the sparc64 version, but sun4m doesn't always use
 * the hardware MIDs, so be careful.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/errno.h>

#include <asm/page.h>
#include <asm/oplib.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/cpudata.h>
#include <asm/cpu_type.h>

extern void clock_stop_probe(void); /* tadpole.c */

static char *cpu_mid_prop(void)
{
	if (sparc_cpu_model == sun4d)
		return "cpu-id";
	return "mid";
}

static int check_cpu_node(phandle nd, int *cur_inst,
		int (*compare)(phandle, int, void *), void *compare_arg,
		phandle *prom_node, int *mid)
{
	if (!compare(nd, *cur_inst, compare_arg)) {
		if (prom_node)
			*prom_node = nd;
		if (mid) {
			*mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
			if (sparc_cpu_model == sun4m)
				*mid &= 3;
		}
		return 0;
	}

	(*cur_inst)++;

	return -ENODEV;
}

static int __cpu_find_by(int (*compare)(phandle, int, void *),
		void *compare_arg, phandle *prom_node, int *mid)
{
	struct device_node *dp;
	int cur_inst;

	cur_inst = 0;
	for_each_node_by_type(dp, "cpu") {
		int err = check_cpu_node(dp->phandle, &cur_inst,
					 compare, compare_arg,
					 prom_node, mid);
		if (!err) {
			of_node_put(dp);
			return 0;
		}
	}

	return -ENODEV;
}

static int cpu_instance_compare(phandle nd, int instance, void *_arg)
{
	int desired_instance = (int) _arg;

	if (instance == desired_instance)
		return 0;
	return -ENODEV;
}

int cpu_find_by_instance(int instance, phandle *prom_node, int *mid)
{
	return __cpu_find_by(cpu_instance_compare, (void *)instance,
			     prom_node, mid);
}

static int cpu_mid_compare(phandle nd, int instance, void *_arg)
{
	int desired_mid = (int) _arg;
	int this_mid;

	this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
	if (this_mid == desired_mid
	    || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))
		return 0;
	return -ENODEV;
}

int cpu_find_by_mid(int mid, phandle *prom_node)
{
	return __cpu_find_by(cpu_mid_compare, (void *)mid,
			     prom_node, NULL);
}

/* sun4m uses truncated mids since we base the cpuid on the ttable/irqset
 * address (0-3).  This gives us the true hardware mid, which might have
 * some other bits set.  On 4d hardware and software mids are the same.
 */
int cpu_get_hwmid(phandle prom_node)
{
	return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);
}

void __init device_scan(void)
{
	printk(KERN_NOTICE "Booting Linux...\n");

#ifndef CONFIG_SMP
	{
		phandle cpu_node;
		int err;
		err = cpu_find_by_instance(0, &cpu_node, NULL);
		if (err) {
			/* Probably a sun4e, Sun is trying to trick us ;-) */
			prom_printf("No cpu nodes, cannot continue\n");
			prom_halt();
		}
		cpu_data(0).clock_tick = prom_getintdefault(cpu_node,
							    "clock-frequency",
							    0);
	}
#endif /* !CONFIG_SMP */

	{
		extern void auxio_probe(void);
		extern void auxio_power_probe(void);
		auxio_probe();
		auxio_power_probe();
	}
	clock_stop_probe();
}