Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* tadpole.c: Probing for the tadpole clock stopping h/w at boot time. |
2 | * | |
3 | * Copyright (C) 1996 David Redman (djhr@tadpole.co.uk) | |
4 | */ | |
5 | ||
6 | #include <linux/string.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/sched.h> | |
9 | #include <linux/init.h> | |
10 | ||
11 | #include <asm/asi.h> | |
12 | #include <asm/oplib.h> | |
13 | #include <asm/io.h> | |
14 | ||
15 | #define MACIO_SCSI_CSR_ADDR 0x78400000 | |
16 | #define MACIO_EN_DMA 0x00000200 | |
17 | #define CLOCK_INIT_DONE 1 | |
18 | ||
19 | static int clk_state; | |
20 | static volatile unsigned char *clk_ctrl; | |
21 | void (*cpu_pwr_save)(void); | |
22 | ||
23 | static inline unsigned int ldphys(unsigned int addr) | |
24 | { | |
25 | unsigned long data; | |
26 | ||
27 | __asm__ __volatile__("\n\tlda [%1] %2, %0\n\t" : | |
28 | "=r" (data) : | |
29 | "r" (addr), "i" (ASI_M_BYPASS)); | |
30 | return data; | |
31 | } | |
32 | ||
33 | static void clk_init(void) | |
34 | { | |
35 | __asm__ __volatile__("mov 0x6c, %%g1\n\t" | |
36 | "mov 0x4c, %%g2\n\t" | |
37 | "mov 0xdf, %%g3\n\t" | |
38 | "stb %%g1, [%0+3]\n\t" | |
39 | "stb %%g2, [%0+3]\n\t" | |
40 | "stb %%g3, [%0+3]\n\t" : : | |
41 | "r" (clk_ctrl) : | |
42 | "g1", "g2", "g3"); | |
43 | } | |
44 | ||
45 | static void clk_slow(void) | |
46 | { | |
47 | __asm__ __volatile__("mov 0xcc, %%g2\n\t" | |
48 | "mov 0x4c, %%g3\n\t" | |
49 | "mov 0xcf, %%g4\n\t" | |
50 | "mov 0xdf, %%g5\n\t" | |
51 | "stb %%g2, [%0+3]\n\t" | |
52 | "stb %%g3, [%0+3]\n\t" | |
53 | "stb %%g4, [%0+3]\n\t" | |
54 | "stb %%g5, [%0+3]\n\t" : : | |
55 | "r" (clk_ctrl) : | |
56 | "g2", "g3", "g4", "g5"); | |
57 | } | |
58 | ||
59 | /* | |
60 | * Tadpole is guaranteed to be UP, using local_irq_save. | |
61 | */ | |
62 | static void tsu_clockstop(void) | |
63 | { | |
64 | unsigned int mcsr; | |
65 | unsigned long flags; | |
66 | ||
67 | if (!clk_ctrl) | |
68 | return; | |
69 | if (!(clk_state & CLOCK_INIT_DONE)) { | |
70 | local_irq_save(flags); | |
71 | clk_init(); | |
72 | clk_state |= CLOCK_INIT_DONE; /* all done */ | |
73 | local_irq_restore(flags); | |
74 | return; | |
75 | } | |
76 | if (!(clk_ctrl[2] & 1)) | |
77 | return; /* no speed up yet */ | |
78 | ||
79 | local_irq_save(flags); | |
80 | ||
81 | /* if SCSI DMA in progress, don't slow clock */ | |
82 | mcsr = ldphys(MACIO_SCSI_CSR_ADDR); | |
83 | if ((mcsr&MACIO_EN_DMA) != 0) { | |
84 | local_irq_restore(flags); | |
85 | return; | |
86 | } | |
87 | /* TODO... the minimum clock setting ought to increase the | |
88 | * memory refresh interval.. | |
89 | */ | |
90 | clk_slow(); | |
91 | local_irq_restore(flags); | |
92 | } | |
93 | ||
94 | static void swift_clockstop(void) | |
95 | { | |
96 | if (!clk_ctrl) | |
97 | return; | |
98 | clk_ctrl[0] = 0; | |
99 | } | |
100 | ||
101 | void __init clock_stop_probe(void) | |
102 | { | |
103 | unsigned int node, clk_nd; | |
104 | char name[20]; | |
105 | ||
106 | prom_getstring(prom_root_node, "name", name, sizeof(name)); | |
107 | if (strncmp(name, "Tadpole", 7)) | |
108 | return; | |
109 | node = prom_getchild(prom_root_node); | |
110 | node = prom_searchsiblings(node, "obio"); | |
111 | node = prom_getchild(node); | |
112 | clk_nd = prom_searchsiblings(node, "clk-ctrl"); | |
113 | if (!clk_nd) | |
114 | return; | |
115 | printk("Clock Stopping h/w detected... "); | |
116 | clk_ctrl = (char *) prom_getint(clk_nd, "address"); | |
117 | clk_state = 0; | |
118 | if (name[10] == '\0') { | |
119 | cpu_pwr_save = tsu_clockstop; | |
120 | printk("enabled (S3)\n"); | |
121 | } else if ((name[10] == 'X') || (name[10] == 'G')) { | |
122 | cpu_pwr_save = swift_clockstop; | |
123 | printk("enabled (%s)\n",name+7); | |
124 | } else | |
125 | printk("disabled %s\n",name+7); | |
126 | } |