From a07c08cea53bb69ce9854d9f31d10e13e3b63b83 Mon Sep 17 00:00:00 2001
From: Andreas Tobler <andreast@FreeBSD.org>
Date: Thu, 28 Nov 2013 21:57:17 +0000
Subject: [PATCH] Give some output about the CPU clock on IBMPOWER machines,
 currently read from OF. Linux does it similar, means they also read the OF
 values and display them.

Tested under qemu and real hardware:

	cpu0: IBM POWER5+ revision 2.0, 1898.10 MHz
---
 sys/powerpc/powerpc/cpu.c | 41 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/sys/powerpc/powerpc/cpu.c b/sys/powerpc/powerpc/cpu.c
index d7f8e2d4d05..dd7ad82fd01 100644
--- a/sys/powerpc/powerpc/cpu.c
+++ b/sys/powerpc/powerpc/cpu.c
@@ -74,6 +74,8 @@
 #include <machine/smp.h>
 #include <machine/spr.h>
 
+#include <dev/ofw/openfirm.h>
+
 static void	cpu_6xx_setup(int cpuid, uint16_t vers);
 static void	cpu_970_setup(int cpuid, uint16_t vers);
 static void	cpu_booke_setup(int cpuid, uint16_t vers);
@@ -273,6 +275,10 @@ cpu_est_clockrate(int cpu_id, uint64_t *cps)
 {
 	uint16_t	vers;
 	register_t	msr;
+	phandle_t	cpu, dev, root;
+	uint32_t	freq[2];
+	int		res  = 0;
+	char		buf[8];
 
 	vers = mfpvr() >> 16;
 	msr = mfmsr();
@@ -316,6 +322,41 @@ cpu_est_clockrate(int cpu_id, uint64_t *cps)
 
 			mtmsr(msr);
 			return (0);
+
+		case IBMPOWER5:
+		case IBMPOWER5PLUS:
+		case IBMPOWER6:
+		case IBMPOWER7:
+		case IBMPOWER7PLUS:
+		case IBMPOWER8:
+			root = OF_peer(0);
+			dev = OF_child(root);
+			while (dev != 0) {
+				res = OF_getprop(dev, "name", buf, sizeof(buf));
+				if (res > 0 && strcmp(buf, "cpus") == 0)
+					break;
+				dev = OF_peer(dev);
+			}
+			cpu = OF_child(dev);
+			while (cpu != 0) {
+				res = OF_getprop(cpu, "device_type", buf,
+						sizeof(buf));
+				if (res > 0 && strcmp(buf, "cpu") == 0)
+					break;
+				cpu = OF_peer(cpu);
+			}
+			if (cpu == 0)
+				return (ENOENT);
+			if (OF_getprop(cpu, "clock-frequency", &freq[0],
+					sizeof(freq[0])))
+					*cps = freq[0];
+			else if (OF_getprop(cpu, "ibm,extended-clock-frequency",
+					&freq, sizeof(freq)))
+					*cps = freq[1];
+			else
+			    *cps = 0;
+
+			return(0);		
 	}
 	
 	return (ENXIO);