drivers/hwmon/coretemp.c: get TjMax value from MSR

[safe/jmp/linux-2.6] / drivers / hwmon / coretemp.c

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index 9fae7cb..2988da1 100644 (file)
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -241,6 +241,55 @@ static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *
        return tjmax;
 }
 
+static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
+                              struct device *dev)
+{
+       /* The 100C is default for both mobile and non mobile CPUs */
+       int err;
+       u32 eax, edx;
+       u32 val;
+
+       /* A new feature of current Intel(R) processors, the
+          IA32_TEMPERATURE_TARGET contains the TjMax value */
+       err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
+       if (err) {
+               dev_warn(dev, "Unable to read TjMax from CPU.\n");
+       } else {
+               val = (eax >> 16) & 0xff;
+               /*
+                * If the TjMax is not plausible, an assumption
+                * will be used
+                */
+               if ((val > 80) && (val < 120)) {
+                       dev_info(dev, "TjMax is %d C.\n", val);
+                       return val * 1000;
+               }
+       }
+
+       /*
+        * An assumption is made for early CPUs and unreadable MSR.
+        * NOTE: the given value may not be correct.
+        */
+
+       switch (c->x86_model) {
+       case 0xe:
+       case 0xf:
+       case 0x16:
+       case 0x1a:
+               dev_warn(dev, "TjMax is assumed as 100 C!\n");
+               return 100000;
+               break;
+       case 0x17:
+       case 0x1c:              /* Atom CPUs */
+               return adjust_tjmax(c, id, dev);
+               break;
+       default:
+               dev_warn(dev, "CPU (model=0x%x) is not supported yet,"
+                       " using default TjMax of 100C.\n", c->x86_model);
+               return 100000;
+       }
+}
+
 static int __devinit coretemp_probe(struct platform_device *pdev)
 {
        struct coretemp_data *data;
@@ -283,14 +332,18 @@ static int __devinit coretemp_probe(struct platform_device *pdev)
                }
        }
 
-       data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
+       data->tjmax = get_tjmax(c, data->id, &pdev->dev);
        platform_set_drvdata(pdev, data);
 
-       /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
-          on older CPUs but not in this register, Atoms don't have it either */
+       /*
+        * read the still undocumented IA32_TEMPERATURE_TARGET. It exists
+        * on older CPUs but not in this register,
+        * Atoms don't have it either.
+        */
 
        if ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
-               err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
+               err = rdmsr_safe_on_cpu(data->id, MSR_IA32_TEMPERATURE_TARGET,
+                   &eax, &edx);
                if (err) {
                        dev_warn(&pdev->dev, "Unable to read"
                                        " IA32_TEMPERATURE_TARGET MSR\n");