| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | { |
| Andres Salomon | 8d12556 | 2010-10-08 14:18:11 -0700 | [diff] [blame] | 103 | phandle node, clk_nd; |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |