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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2005-11-07 14:27:33 +1100
committerPaul Mackerras <paulus@samba.org>2005-11-08 11:17:34 +1100
commit4350147a816b9c5b40fa59e4fa23f17490630b79 (patch)
treec333986047de60aa90809d669895726610c0c3e5 /arch/ppc64/kernel
parenta82765b6eee3d1267ded3320ca67b39fe1844599 (diff)
[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 <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc64/kernel')
-rw-r--r--arch/ppc64/kernel/misc.S72
1 files changed, 71 insertions, 1 deletions
diff --git a/arch/ppc64/kernel/misc.S b/arch/ppc64/kernel/misc.S
index 077507ffbab8..914632ec587d 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)
@@ -593,6 +593,76 @@ _GLOBAL(real_writeb)
#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)
*/