hwmon: (coretemp) Add support for Penryn mobile CPUs

Following patch adds support for mobile Penryn CPUs. Intel documents this
poorly. I asked the Coretemp author for some help. This is totally untested and
may not work. Please test!

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Cc: Huaxu Wan <huaxu.wan@linux.intel.com>
Cc: Kent Liu <kent.liu@linux.intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

2 files changed, 26 insertions, 4 deletions

diff --git a/Documentation/hwmon/coretemp b/Documentation/hwmon/coretemp
index d3d79e658718..65d1e667c36e 100644
--- a/Documentation/hwmon/coretemp
+++ b/Documentation/hwmon/coretemp
@@ -4,7 +4,9 @@ Kernel driver coretemp
 Supported chips:
   * All Intel Core family
     Prefix: 'coretemp'
-    CPUID: family 0x6, models 0xe, 0xf, 0x16, 0x17, 0x1c (Atom)
+    CPUID: family 0x6, models 0xe (Pentium M DC), 0xf (Core 2 DC 65nm),
+                              0x16 (Core 2 SC 65nm), 0x17 (Penryn 45nm),
+                              0x1a (Nehalem), 0x1c (Atom).
     Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
                Volume 3A: System Programming Guide
                http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 4c15ed7eb786..c86b1247b94c 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -157,6 +157,7 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
         /* The 100C is default for both mobile and non mobile CPUs */
 
         int tjmax = 100000;
+        int tjmax_ee = 85000;
         int usemsr_ee = 1;
         int err;
         u32 eax, edx;
@@ -175,6 +176,7 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
         }
 
         if ((c->x86_model > 0xe) && (usemsr_ee)) {
+                u8 platform_id;
 
                 /* Now we can detect the mobile CPU using Intel provided table
                    http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
@@ -187,8 +189,24 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
                                  "Unable to access MSR 0x17, assuming desktop"
                                  " CPU\n");
                         usemsr_ee = 0;
-                } else if (!(eax & 0x10000000)) {
+                } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
+                        /* Trust bit 28 up to Penryn, I could not find any
+                           documentation on that; if you happen to know
+                           someone at Intel please ask */
                         usemsr_ee = 0;
+                } else {
+                        /* Platform ID bits 52:50 (EDX starts at bit 32) */
+                        platform_id = (edx >> 18) & 0x7;
+
+                        /* Mobile Penryn CPU seems to be platform ID 7 or 5
+                          (guesswork) */
+                        if ((c->x86_model == 0x17) &&
+                            ((platform_id == 5) || (platform_id == 7))) {
+                                /* If MSR EE bit is set, set it to 90 degrees C,
+                                   otherwise 105 degrees C */
+                                tjmax_ee = 90000;
+                                tjmax = 105000;
+                        }
                 }
         }
 
@@ -200,7 +218,7 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
                                  "Unable to access MSR 0xEE, for Tjmax, left"
                                  " at default");
                 } else if (eax & 0x40000000) {
-                        tjmax = 85000;
+                        tjmax = tjmax_ee;
                 }
         /* if we dont use msr EE it means we are desktop CPU (with exeception
            of Atom) */
@@ -422,7 +440,9 @@ static int __init coretemp_init(void)
         for_each_online_cpu(i) {
                 struct cpuinfo_x86 *c = &cpu_data(i);
 
-                /* check if family 6, models 0xe, 0xf, 0x16, 0x17, 0x1A, 0x1c */
+                /* check if family 6, models 0xe (Pentium M DC),
+                  0xf (Core 2 DC 65nm), 0x16 (Core 2 SC 65nm),
+                  0x17 (Penryn 45nm), 0x1a (Nehalem), 0x1c (Atom) */
                 if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
                     !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
                         (c->x86_model == 0x16) || (c->x86_model == 0x17) ||