hwmon: (dell-smm) Detect fan with index=2

Some Dell machines (e.g. Dell Precision M3800) have two fans, first with
index=0 and second with index=2. So export also attributes for third fan
device with index=2.

Reported-by: Tolga Cakir <cevelnet@gmail.com>
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Tolga Cakir <cevelnet@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 2ac87d553e22..571d4984d39c 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -81,6 +81,7 @@ static bool disallow_fan_type_call;
 #define I8K_HWMON_HAVE_TEMP4    (1 << 3)
 #define I8K_HWMON_HAVE_FAN1     (1 << 4)
 #define I8K_HWMON_HAVE_FAN2     (1 << 5)
+#define I8K_HWMON_HAVE_FAN3     (1 << 6)
 
 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
@@ -252,7 +253,7 @@ static int _i8k_get_fan_type(int fan)
 static int i8k_get_fan_type(int fan)
 {
         /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
-        static int types[2] = { INT_MIN, INT_MIN };
+        static int types[3] = { INT_MIN, INT_MIN, INT_MIN };
 
         if (types[fan] == INT_MIN)
                 types[fan] = _i8k_get_fan_type(fan);
@@ -719,6 +720,12 @@ static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
                           1);
 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
                           i8k_hwmon_set_pwm, 1);
+static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
+                          2);
+static SENSOR_DEVICE_ATTR(fan3_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
+                          2);
+static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
+                          i8k_hwmon_set_pwm, 2);
 
 static struct attribute *i8k_attrs[] = {
         &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
@@ -735,6 +742,9 @@ static struct attribute *i8k_attrs[] = {
         &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
         &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
         &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
+        &sensor_dev_attr_fan3_input.dev_attr.attr,      /* 14 */
+        &sensor_dev_attr_fan3_label.dev_attr.attr,      /* 15 */
+        &sensor_dev_attr_pwm3.dev_attr.attr,            /* 16 */
         NULL
 };
 
@@ -742,7 +752,7 @@ static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
                               int index)
 {
         if (disallow_fan_type_call &&
-            (index == 9 || index == 12))
+            (index == 9 || index == 12 || index == 15))
                 return 0;
         if (index >= 0 && index <= 1 &&
             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
@@ -762,6 +772,9 @@ static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
         if (index >= 11 && index <= 13 &&
             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
                 return 0;
+        if (index >= 14 && index <= 16 &&
+            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN3))
+                return 0;
 
         return attr->mode;
 }
@@ -807,6 +820,13 @@ static int __init i8k_init_hwmon(void)
         if (err >= 0)
                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 
+        /* Third fan attributes, if fan status or type is OK */
+        err = i8k_get_fan_status(2);
+        if (err < 0)
+                err = i8k_get_fan_type(2);
+        if (err >= 0)
+                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN3;
+
         i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
                                                           NULL, i8k_groups);
         if (IS_ERR(i8k_hwmon_dev)) {