1 files changed, 34 insertions, 8 deletions

diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
index eb648d9c91d6..9ab034a1b4c1 100644
--- a/drivers/hwmon/f75375s.c
+++ b/drivers/hwmon/f75375s.c
@@ -264,6 +264,21 @@ static inline u16 rpm_to_reg(int rpm)
         return 1500000 / rpm;
 }
 
+static bool duty_mode_enabled(u8 pwm_enable)
+{
+        switch (pwm_enable) {
+        case 0: /* Manual, duty mode (full speed) */
+        case 1: /* Manual, duty mode */
+        case 4: /* Auto, duty mode */
+                return true;
+        case 2: /* Auto, speed mode */
+        case 3: /* Manual, speed mode */
+                return false;
+        default:
+                BUG();
+        }
+}
+
 static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
                 const char *buf, size_t count)
 {
@@ -337,11 +352,15 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
         struct f75375_data *data = i2c_get_clientdata(client);
         u8 fanmode;
 
-        if (val < 0 || val > 3)
+        if (val < 0 || val > 4)
                 return -EINVAL;
 
         fanmode = f75375_read8(client, F75375_REG_FAN_TIMER);
         if (data->kind == f75387) {
+                /* For now, deny dangerous toggling of duty mode */
+                if (duty_mode_enabled(data->pwm_enable[nr]) !=
+                                duty_mode_enabled(val))
+                        return -EOPNOTSUPP;
                 /* clear each fanX_mode bit before setting them properly */
                 fanmode &= ~(1 << F75387_FAN_DUTY_MODE(nr));
                 fanmode &= ~(1 << F75387_FAN_MANU_MODE(nr));
@@ -355,12 +374,14 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
                         fanmode  |= (1 << F75387_FAN_MANU_MODE(nr));
                         fanmode  |= (1 << F75387_FAN_DUTY_MODE(nr));
                         break;
-                case 2: /* AUTOMATIC*/
-                        fanmode  |=  (1 << F75387_FAN_DUTY_MODE(nr));
+                case 2: /* Automatic, speed mode */
                         break;
                 case 3: /* fan speed */
                         fanmode |= (1 << F75387_FAN_MANU_MODE(nr));
                         break;
+                case 4: /* Automatic, pwm */
+                        fanmode |= (1 << F75387_FAN_DUTY_MODE(nr));
+                        break;
                 }
         } else {
                 /* clear each fanX_mode bit before setting them properly */
@@ -378,6 +399,8 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
                         break;
                 case 3: /* fan speed */
                         break;
+                case 4: /* Automatic pwm */
+                        return -EINVAL;
                 }
         }
 
@@ -735,14 +758,17 @@ static void f75375_init(struct i2c_client *client, struct f75375_data *data,
 
                                 manu = ((mode >> F75387_FAN_MANU_MODE(nr)) & 1);
                                 duty = ((mode >> F75387_FAN_DUTY_MODE(nr)) & 1);
-                                if (manu && duty)
-                                        /* speed */
+                                if (!manu && duty)
+                                        /* auto, pwm */
+                                        data->pwm_enable[nr] = 4;
+                                else if (manu && !duty)
+                                        /* manual, speed */
                                         data->pwm_enable[nr] = 3;
-                                else if (!manu && duty)
-                                        /* automatic */
+                                else if (!manu && !duty)
+                                        /* automatic, speed */
                                         data->pwm_enable[nr] = 2;
                                 else
-                                        /* manual */
+                                        /* manual, pwm */
                                         data->pwm_enable[nr] = 1;
                         } else {
                                 if (!(conf & (1 << F75375_FAN_CTRL_LINEAR(nr))))