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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/kernel/tadpole.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/sparc/kernel/tadpole.c')
-rw-r--r-- | arch/sparc/kernel/tadpole.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/sparc/kernel/tadpole.c b/arch/sparc/kernel/tadpole.c new file mode 100644 index 000000000000..f476a5f4af6a --- /dev/null +++ b/arch/sparc/kernel/tadpole.c @@ -0,0 +1,126 @@ +/* tadpole.c: Probing for the tadpole clock stopping h/w at boot time. + * + * Copyright (C) 1996 David Redman (djhr@tadpole.co.uk) + */ + +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/init.h> + +#include <asm/asi.h> +#include <asm/oplib.h> +#include <asm/io.h> + +#define MACIO_SCSI_CSR_ADDR 0x78400000 +#define MACIO_EN_DMA 0x00000200 +#define CLOCK_INIT_DONE 1 + +static int clk_state; +static volatile unsigned char *clk_ctrl; +void (*cpu_pwr_save)(void); + +static inline unsigned int ldphys(unsigned int addr) +{ + unsigned long data; + + __asm__ __volatile__("\n\tlda [%1] %2, %0\n\t" : + "=r" (data) : + "r" (addr), "i" (ASI_M_BYPASS)); + return data; +} + +static void clk_init(void) +{ + __asm__ __volatile__("mov 0x6c, %%g1\n\t" + "mov 0x4c, %%g2\n\t" + "mov 0xdf, %%g3\n\t" + "stb %%g1, [%0+3]\n\t" + "stb %%g2, [%0+3]\n\t" + "stb %%g3, [%0+3]\n\t" : : + "r" (clk_ctrl) : + "g1", "g2", "g3"); +} + +static void clk_slow(void) +{ + __asm__ __volatile__("mov 0xcc, %%g2\n\t" + "mov 0x4c, %%g3\n\t" + "mov 0xcf, %%g4\n\t" + "mov 0xdf, %%g5\n\t" + "stb %%g2, [%0+3]\n\t" + "stb %%g3, [%0+3]\n\t" + "stb %%g4, [%0+3]\n\t" + "stb %%g5, [%0+3]\n\t" : : + "r" (clk_ctrl) : + "g2", "g3", "g4", "g5"); +} + +/* + * Tadpole is guaranteed to be UP, using local_irq_save. + */ +static void tsu_clockstop(void) +{ + unsigned int mcsr; + unsigned long flags; + + if (!clk_ctrl) + return; + if (!(clk_state & CLOCK_INIT_DONE)) { + local_irq_save(flags); + clk_init(); + clk_state |= CLOCK_INIT_DONE; /* all done */ + local_irq_restore(flags); + return; + } + if (!(clk_ctrl[2] & 1)) + return; /* no speed up yet */ + + local_irq_save(flags); + + /* if SCSI DMA in progress, don't slow clock */ + mcsr = ldphys(MACIO_SCSI_CSR_ADDR); + if ((mcsr&MACIO_EN_DMA) != 0) { + local_irq_restore(flags); + return; + } + /* TODO... the minimum clock setting ought to increase the + * memory refresh interval.. + */ + clk_slow(); + local_irq_restore(flags); +} + +static void swift_clockstop(void) +{ + if (!clk_ctrl) + return; + clk_ctrl[0] = 0; +} + +void __init clock_stop_probe(void) +{ + unsigned int node, clk_nd; + char name[20]; + + prom_getstring(prom_root_node, "name", name, sizeof(name)); + if (strncmp(name, "Tadpole", 7)) + return; + node = prom_getchild(prom_root_node); + node = prom_searchsiblings(node, "obio"); + node = prom_getchild(node); + clk_nd = prom_searchsiblings(node, "clk-ctrl"); + if (!clk_nd) + return; + printk("Clock Stopping h/w detected... "); + clk_ctrl = (char *) prom_getint(clk_nd, "address"); + clk_state = 0; + if (name[10] == '\0') { + cpu_pwr_save = tsu_clockstop; + printk("enabled (S3)\n"); + } else if ((name[10] == 'X') || (name[10] == 'G')) { + cpu_pwr_save = swift_clockstop; + printk("enabled (%s)\n",name+7); + } else + printk("disabled %s\n",name+7); +} |