hwmon: (ibmpowernv) pretty print labels

The new OPAL device tree adds a few properties which can be used to add
extra information on the sensor label.

In the case of a cpu core sensor, the firmware exposes the physical
identifier of the core in the "ibm,pir" property. The driver
translates this identifier in a linux cpu number and prints out a
range corresponding to the hardware threads of the core (as they
share the same sensor).

The numbering gives a hint on the localization of the core in the
system (which socket, which chip).

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
index 1180ce6..7108daf 100644 (file)
--- a/drivers/hwmon/ibmpowernv.c
+++ b/drivers/hwmon/ibmpowernv.c
@@ -30,6 +30,7 @@
 #include <linux/platform_device.h>
 #include <asm/opal.h>
 #include <linux/err.h>
+#include <asm/cputhreads.h>
 
 #define MAX_ATTR_LEN   32
 #define MAX_LABEL_LEN  64
@@ -112,13 +113,53 @@ static ssize_t show_label(struct device *dev, struct device_attribute *devattr,
        return sprintf(buf, "%s\n", sdata->label);
 }
 
+static int __init get_logical_cpu(int hwcpu)
+{
+       int cpu;
+
+       for_each_possible_cpu(cpu)
+               if (get_hard_smp_processor_id(cpu) == hwcpu)
+                       return cpu;
+
+       return -ENOENT;
+}
+
 static void __init make_sensor_label(struct device_node *np,
                                     struct sensor_data *sdata,
                                     const char *label)
 {
+       u32 id;
        size_t n;
 
        n = snprintf(sdata->label, sizeof(sdata->label), "%s", label);
+
+       /*
+        * Core temp pretty print
+        */
+       if (!of_property_read_u32(np, "ibm,pir", &id)) {
+               int cpuid = get_logical_cpu(id);
+
+               if (cpuid >= 0)
+                       /*
+                        * The digital thermal sensors are associated
+                        * with a core. Let's print out the range of
+                        * cpu ids corresponding to the hardware
+                        * threads of the core.
+                        */
+                       n += snprintf(sdata->label + n,
+                                     sizeof(sdata->label) - n, " %d-%d",
+                                     cpuid, cpuid + threads_per_core - 1);
+               else
+                       n += snprintf(sdata->label + n,
+                                     sizeof(sdata->label) - n, " phy%d", id);
+       }
+
+       /*
+        * Membuffer pretty print
+        */
+       if (!of_property_read_u32(np, "ibm,chip-id", &id))
+               n += snprintf(sdata->label + n, sizeof(sdata->label) - n,
+                             " %d", id & 0xffff);
 }
 
 static int get_sensor_index_attr(const char *name, u32 *index, char *attr)