hwmon: (lm85) Select the closest PWM frequency

The LM85 and compatible chips only support 8 arbitrary PWM frequencies.
The algorithm to pick one of them based on the user input is not
optimum. Improve it to always pick the closest supported frequency.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NHerbert Poetzl <herbert@13thfloor.at>

drivers/hwmon/lm85.c

@@ -199,10 +199,9 @@ static int FREQ_TO_REG(int freq)
 {
 	int i;
 
-	if (freq >= lm85_freq_map[7])
-		return 7;
+	/* Find the closest match */
 	for (i = 0; i < 7; ++i)
-		if (freq <= lm85_freq_map[i])
+		if (freq <= (lm85_freq_map[i] + lm85_freq_map[i + 1]) / 2)
 			break;
 	return i;
 }