hwmon: (applesmc) Ignore some temperature registers

Not all sensors in the T range are useful temperatures.  This patch
creates a subset of sensors to be exported to userland, excluding the
unknown types.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 47 insertions, 28 deletions

diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index 75f87f125dac..4d937a18fadb 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -133,11 +133,13 @@ static struct applesmc_registers {
         unsigned int temp_count;        /* number of temperature registers */
         unsigned int temp_begin;        /* temperature lower index bound */
         unsigned int temp_end;          /* temperature upper index bound */
+        unsigned int index_count;       /* size of temperature index array */
         int num_light_sensors;          /* number of light sensors */
         bool has_accelerometer;         /* has motion sensor */
         bool has_key_backlight;         /* has keyboard backlight */
         bool init_complete;             /* true when fully initialized */
         struct applesmc_entry *cache;   /* cached key entries */
+        const char **index;             /* temperature key index */
 } smcreg = {
         .mutex = __MUTEX_INITIALIZER(smcreg.mutex),
 };
@@ -469,6 +471,30 @@ static void applesmc_device_init(void)
         pr_warn("failed to init the device\n");
 }
 
+static int applesmc_init_index(struct applesmc_registers *s)
+{
+        const struct applesmc_entry *entry;
+        unsigned int i;
+
+        if (s->index)
+                return 0;
+
+        s->index = kcalloc(s->temp_count, sizeof(s->index[0]), GFP_KERNEL);
+        if (!s->index)
+                return -ENOMEM;
+
+        for (i = s->temp_begin; i < s->temp_end; i++) {
+                entry = applesmc_get_entry_by_index(i);
+                if (IS_ERR(entry))
+                        continue;
+                if (strcmp(entry->type, TEMP_SENSOR_TYPE))
+                        continue;
+                s->index[s->index_count++] = entry->key;
+        }
+
+        return 0;
+}
+
 /*
  * applesmc_init_smcreg_try - Try to initialize register cache. Idempotent.
  */
@@ -504,6 +530,10 @@ static int applesmc_init_smcreg_try(void)
                 return ret;
         s->temp_count = s->temp_end - s->temp_begin;
 
+        ret = applesmc_init_index(s);
+        if (ret)
+                return ret;
+
         ret = applesmc_has_key(LIGHT_SENSOR_LEFT_KEY, &left_light_sensor);
         if (ret)
                 return ret;
@@ -520,8 +550,8 @@ static int applesmc_init_smcreg_try(void)
         s->num_light_sensors = left_light_sensor + right_light_sensor;
         s->init_complete = true;
 
-        pr_info("key=%d fan=%d temp=%d acc=%d lux=%d kbd=%d\n",
-               s->key_count, s->fan_count, s->temp_count,
+        pr_info("key=%d fan=%d temp=%d index=%d acc=%d lux=%d kbd=%d\n",
+               s->key_count, s->fan_count, s->temp_count, s->index_count,
                s->has_accelerometer,
                s->num_light_sensors,
                s->has_key_backlight);
@@ -529,6 +559,15 @@ static int applesmc_init_smcreg_try(void)
         return 0;
 }
 
+static void applesmc_destroy_smcreg(void)
+{
+        kfree(smcreg.index);
+        smcreg.index = NULL;
+        kfree(smcreg.cache);
+        smcreg.cache = NULL;
+        smcreg.init_complete = false;
+}
+
 /*
  * applesmc_init_smcreg - Initialize register cache.
  *
@@ -549,19 +588,11 @@ static int applesmc_init_smcreg(void)
                 msleep(INIT_WAIT_MSECS);
         }
 
-        kfree(smcreg.cache);
-        smcreg.cache = NULL;
+        applesmc_destroy_smcreg();
 
         return ret;
 }
 
-static void applesmc_destroy_smcreg(void)
-{
-        kfree(smcreg.cache);
-        smcreg.cache = NULL;
-        smcreg.init_complete = false;
-}
-
 /* Device model stuff */
 static int applesmc_probe(struct platform_device *dev)
 {
@@ -705,33 +736,21 @@ out:
 static ssize_t applesmc_show_sensor_label(struct device *dev,
                         struct device_attribute *devattr, char *sysfsbuf)
 {
-        int index = smcreg.temp_begin + to_index(devattr);
-        const struct applesmc_entry *entry;
+        const char *key = smcreg.index[to_index(devattr)];
 
-        entry = applesmc_get_entry_by_index(index);
-        if (IS_ERR(entry))
-                return PTR_ERR(entry);
-
-        return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", entry->key);
+        return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", key);
 }
 
 /* Displays degree Celsius * 1000 */
 static ssize_t applesmc_show_temperature(struct device *dev,
                         struct device_attribute *devattr, char *sysfsbuf)
 {
-        int index = smcreg.temp_begin + to_index(devattr);
-        const struct applesmc_entry *entry;
+        const char *key = smcreg.index[to_index(devattr)];
         int ret;
         s16 value;
         int temp;
 
-        entry = applesmc_get_entry_by_index(index);
-        if (IS_ERR(entry))
-                return PTR_ERR(entry);
-        if (strcmp(entry->type, TEMP_SENSOR_TYPE))
-                return -EINVAL;
-
-        ret = applesmc_read_s16(entry->key, &value);
+        ret = applesmc_read_s16(key, &value);
         if (ret)
                 return ret;
 
@@ -1247,7 +1266,7 @@ static int __init applesmc_init(void)
         if (ret)
                 goto out_info;
 
-        ret = applesmc_create_nodes(temp_group, smcreg.temp_count);
+        ret = applesmc_create_nodes(temp_group, smcreg.index_count);
         if (ret)
                 goto out_fans;