From 4350147a816b9c5b40fa59e4fa23f17490630b79 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 7 Nov 2005 14:27:33 +1100 Subject: [PATCH] ppc64: SMU based macs cpufreq support CPU freq support using 970FX powertune facility for iMac G5 and SMU based single CPU desktop. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras --- arch/ppc64/kernel/misc.S | 72 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) (limited to 'arch/ppc64/kernel') diff --git a/arch/ppc64/kernel/misc.S b/arch/ppc64/kernel/misc.S index 077507ffbab..914632ec587 100644 --- a/arch/ppc64/kernel/misc.S +++ b/arch/ppc64/kernel/misc.S @@ -560,7 +560,7 @@ _GLOBAL(real_readb) isync blr - /* +/* * Do an IO access in real mode */ _GLOBAL(real_writeb) @@ -592,6 +592,76 @@ _GLOBAL(real_writeb) blr #endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */ +/* + * SCOM access functions for 970 (FX only for now) + * + * unsigned long scom970_read(unsigned int address); + * void scom970_write(unsigned int address, unsigned long value); + * + * The address passed in is the 24 bits register address. This code + * is 970 specific and will not check the status bits, so you should + * know what you are doing. + */ +_GLOBAL(scom970_read) + /* interrupts off */ + mfmsr r4 + ori r0,r4,MSR_EE + xori r0,r0,MSR_EE + mtmsrd r0,1 + + /* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits + * (including parity). On current CPUs they must be 0'd, + * and finally or in RW bit + */ + rlwinm r3,r3,8,0,15 + ori r3,r3,0x8000 + + /* do the actual scom read */ + sync + mtspr SPRN_SCOMC,r3 + isync + mfspr r3,SPRN_SCOMD + isync + mfspr r0,SPRN_SCOMC + isync + + /* XXX: fixup result on some buggy 970's (ouch ! we lost a bit, bah + * that's the best we can do). Not implemented yet as we don't use + * the scom on any of the bogus CPUs yet, but may have to be done + * ultimately + */ + + /* restore interrupts */ + mtmsrd r4,1 + blr + + +_GLOBAL(scom970_write) + /* interrupts off */ + mfmsr r5 + ori r0,r5,MSR_EE + xori r0,r0,MSR_EE + mtmsrd r0,1 + + /* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits + * (including parity). On current CPUs they must be 0'd. + */ + + rlwinm r3,r3,8,0,15 + + sync + mtspr SPRN_SCOMD,r4 /* write data */ + isync + mtspr SPRN_SCOMC,r3 /* write command */ + isync + mfspr 3,SPRN_SCOMC + isync + + /* restore interrupts */ + mtmsrd r5,1 + blr + + /* * Create a kernel thread * kernel_thread(fn, arg, flags) -- cgit v1.2.3