Linux 2.6.31.6
[linux/fpc-iii.git] / arch / sparc / kernel / devices.c
blobb171ae8de90dc5b49aa410c03c166603c37b4d02
1 /* devices.c: Initial scan of the prom device tree for important
2 * Sparc device nodes which we need to find.
4 * This is based on the sparc64 version, but sun4m doesn't always use
5 * the hardware MIDs, so be careful.
7 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
8 */
10 #include <linux/kernel.h>
11 #include <linux/threads.h>
12 #include <linux/string.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
16 #include <asm/page.h>
17 #include <asm/oplib.h>
18 #include <asm/prom.h>
19 #include <asm/smp.h>
20 #include <asm/system.h>
21 #include <asm/cpudata.h>
23 extern void cpu_probe(void);
24 extern void clock_stop_probe(void); /* tadpole.c */
25 extern void sun4c_probe_memerr_reg(void);
27 static char *cpu_mid_prop(void)
29 if (sparc_cpu_model == sun4d)
30 return "cpu-id";
31 return "mid";
34 static int check_cpu_node(int nd, int *cur_inst,
35 int (*compare)(int, int, void *), void *compare_arg,
36 int *prom_node, int *mid)
38 if (!compare(nd, *cur_inst, compare_arg)) {
39 if (prom_node)
40 *prom_node = nd;
41 if (mid) {
42 *mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
43 if (sparc_cpu_model == sun4m)
44 *mid &= 3;
46 return 0;
49 (*cur_inst)++;
51 return -ENODEV;
54 static int __cpu_find_by(int (*compare)(int, int, void *), void *compare_arg,
55 int *prom_node, int *mid)
57 struct device_node *dp;
58 int cur_inst;
60 cur_inst = 0;
61 for_each_node_by_type(dp, "cpu") {
62 int err = check_cpu_node(dp->node, &cur_inst,
63 compare, compare_arg,
64 prom_node, mid);
65 if (!err) {
66 of_node_put(dp);
67 return 0;
71 return -ENODEV;
74 static int cpu_instance_compare(int nd, int instance, void *_arg)
76 int desired_instance = (int) _arg;
78 if (instance == desired_instance)
79 return 0;
80 return -ENODEV;
83 int cpu_find_by_instance(int instance, int *prom_node, int *mid)
85 return __cpu_find_by(cpu_instance_compare, (void *)instance,
86 prom_node, mid);
89 static int cpu_mid_compare(int nd, int instance, void *_arg)
91 int desired_mid = (int) _arg;
92 int this_mid;
94 this_mid = prom_getintdefault(nd, cpu_mid_prop(), 0);
95 if (this_mid == desired_mid
96 || (sparc_cpu_model == sun4m && (this_mid & 3) == desired_mid))
97 return 0;
98 return -ENODEV;
101 int cpu_find_by_mid(int mid, int *prom_node)
103 return __cpu_find_by(cpu_mid_compare, (void *)mid,
104 prom_node, NULL);
107 /* sun4m uses truncated mids since we base the cpuid on the ttable/irqset
108 * address (0-3). This gives us the true hardware mid, which might have
109 * some other bits set. On 4d hardware and software mids are the same.
111 int cpu_get_hwmid(int prom_node)
113 return prom_getintdefault(prom_node, cpu_mid_prop(), -ENODEV);
116 void __init device_scan(void)
118 prom_printf("Booting Linux...\n");
120 #ifndef CONFIG_SMP
122 int err, cpu_node;
123 err = cpu_find_by_instance(0, &cpu_node, NULL);
124 if (err) {
125 /* Probably a sun4e, Sun is trying to trick us ;-) */
126 prom_printf("No cpu nodes, cannot continue\n");
127 prom_halt();
129 cpu_data(0).clock_tick = prom_getintdefault(cpu_node,
130 "clock-frequency",
133 #endif /* !CONFIG_SMP */
135 cpu_probe();
137 extern void auxio_probe(void);
138 extern void auxio_power_probe(void);
139 auxio_probe();
140 auxio_power_probe();
142 clock_stop_probe();
144 if (ARCH_SUN4C)
145 sun4c_probe_memerr_reg();
147 return;