Drop PWM support for as99127f. Update AS99127F docs.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2428 7894878c-1315-0410-8ee3-d5d059ff63e0

doc/chips/SUMMARY

@@ -182,7 +182,7 @@ w83627hf
 	w83697hf	2	8	2	2 pwm	no	yes (LPC)
 
 w83781d
-	as99127f	3	7	3	2 pwm?  yes	no
+	as99127f	3	7	3	-	yes	no
 	w83781d		3	7	3	-	yes	yes
 	w83782d		3	9	3	2-4 pwm	yes	yes
 	w83783s		1-2	5-6	3	2 pwm	yes	no

doc/chips/w83781d

@@ -188,7 +188,8 @@ Known problems:
 AS99127F PROBLEMS
 -----------------
 The as99127f support was developed without the benefit of a datasheet.
-In most cases it is treated as a w83781d.
+In most cases it is treated as a w83781d (although revision 2 of the
+AS9917F looks more like a w83782d).
 This support will be BETA until a datasheet is released.
 One user has reported problems with fans stopping
 occasionally.
@@ -199,13 +200,9 @@ disable, not enable. This may be changed in the future.
 
 Known problems:
 	- Problems with diode/thermistor settings (supported?)
-	- fan_div register may not really be fan_div.
 	- One user reports fans stopping under high server load.
-	- Some as99127f chips are misidentified as a w83781d or w83782d.
+	- Revision 2 seems to have 2 PWM registers but we don't know
-	  This is caused by the chip having the wrong WCHIPID register
+	  how to handle them. More details below.
-	  value, so there is no fix. The workaround is to use the
-          force_as99127f parameter.
-	  (modprobe w83781d force_as99127f=BUS,0x2d where BUS is your i2c bus number)
 
 These will not be fixed unless we get a datasheet.
 If you have problems, please lobby Asus to release a datasheet.
@@ -524,13 +521,13 @@ See the lm78 documentation for details.
 
 Additional entries not in the lm78:
 
-	pwm[1-4]: (not on w83781d)
+	pwm[1-4]: (not on w83781d nor as99127f)
 	  Controls the speed of the fans with PWM (Pulse Width Modulation)
 	  Valid values:
 	    0 - 255. 255 = max speed.
         Second value is PWM enable 0/1.
 
-	sensor[1-3]: (not on w83781d)
+	sensor[1-3]: (not on w83781d nor as99127f)
 	  Controls the sensor type. To change to a different
 	  sensor type, for example, do 'echo 2 > sensor1'.
 	  Valid values:
@@ -541,7 +538,7 @@ Additional entries not in the lm78:
 	  Thermistors with other Betas could in theory be supported
 	  after correspondence with Winbond. See below.
 
-	rt[1-3]: (781d only)
+	rt[1-3]: (w83781d only)
 	  32-byte tables controlling the conversion from
 	  resistance to temperature for thermistors.
 	  For the curious only. Writing to these entries will
@@ -580,8 +577,6 @@ NOTES:
 
 Data sheet updates:
 ------------------
-	- Mask off lower bit of all ID registers.
-
 	- PWM clock registers:
 
 		000: master /  512
@@ -739,3 +734,49 @@ in3=r(0x23)*0.016*1.68
 in4=r(0x24)*0.016*4
 in5=255
 in6=255
+
+
+# PWM
+
+Additional info about PWM on the AS99127F (may apply to other Asus
+chips as well) by Jean Delvare as of 2004-04-09:
+
+AS99127F revision 2 seems to have two PWM registers at 0x59 and 0x5A,
+and a temperature sensor type selector at 0x5B (which basically means
+that they swapped registers 0x59 and 0x5B when you compare with Winbond
+chips).
+Revision 1 of the chip also has the temperature sensor type selector at
+0x5B, but PWM registers have no effect.
+
+We don't know exactly how the temperature sensor type selection works.
+Looks like bits 1-0 are for temp1, bits 3-2 for temp2 and bits 5-4 for
+temp3, although it is possible that only the most significant bit matters
+each time. So far, values other than 0 always broke the readings.
+
+PWM registers seem to be split in two parts: bit 7 is a mode selector,
+while the other bits seem to define a value or threshold.
+
+When bit 7 is clear, bits 6-0 seem to hold a threshold value. If the value
+is below a given limit, the fan runs at low speed. If the value is above
+the limit, the fan runs at full speed. We have no clue as to what the limit
+represents. Note that there seem to be some inertia in this mode, speed
+changes may need some time to trigger. Also, an hysteresis mechanism is
+suspected since walking through all the values increasingly and then
+decreasingly led to slighlty different limits.
+
+When bit 7 is set, bits 3-0 seem to hold a threshold value, while bits 6-4
+would not be significant. If the value is below a given limit, the fan runs
+at full speed, while if it is above the limit it runs at low speed (so this
+is the contrary of the other mode, in a way). Here again, we don't know
+what the limit is supposed to represent.
+
+One remarkable thing is that the fans would only have two or three
+different speeds (transitional states left apart), not a whole range as
+you usually get with PWM.
+
+As a conclusion, you can write 0x00 or 0x8F to the PWM registers to make
+fans run at low speed, and 0x7F or 0x80 to make them run at full speed.
+
+Please contact us if you can figure out how it is supposed to work. As
+long as we don't know more, the w83781d driver doesn't handle PWM on
+AS99127F chips at all.

kernel/chips/w83781d.c

@@ -24,7 +24,7 @@
     Supports following chips:
 
     Chip	#vin	#fanin	#pwm	#temp	wchipid	vendid	i2c	ISA
-    as99127f	7	3	1?	3	0x31	0x12c3	yes	no
+    as99127f	7	3	0	3	0x31	0x12c3	yes	no
     as99127f rev.2 (type name = as99127f)	0x31	0x5ca3	yes	no
     w83627hf	9	3	2	3	0x21	0x5ca3	yes	yes(LPC)
     w83697hf	8	2	2	2	0x60	0x5ca3	no	yes(LPC)
@@ -442,10 +442,6 @@ static ctl_table as99127f_dir_table_template[] = {
 	 &i2c_sysctl_real, NULL, &w83781d_alarms},
 	{W83781D_SYSCTL_BEEP, "beep", NULL, 0, 0644, NULL, &i2c_proc_real,
 	 &i2c_sysctl_real, NULL, &w83781d_beep},
-	{W83781D_SYSCTL_PWM1, "pwm1", NULL, 0, 0644, NULL, &i2c_proc_real,
-	 &i2c_sysctl_real, NULL, &w83781d_pwm},
-	{W83781D_SYSCTL_PWM2, "pwm2", NULL, 0, 0644, NULL, &i2c_proc_real,
-	 &i2c_sysctl_real, NULL, &w83781d_pwm},
 	{0}
 };
 
@@ -1062,6 +1058,10 @@ static int w83781d_detect(struct i2c_adapter *adapter, int address,
 	}
 	data->sysctl_id = i;
 
+	/* Only PWM2 can be disabled */
+	for(i = 0; i < 4; i++)
+		data->pwmenable[i] = 1;
+
 	/* Initialize the chip */
 	w83781d_init_client(new_client);
 	return 0;
@@ -1379,9 +1379,6 @@ static void w83781d_init_client(struct i2c_client *client)
 			if (!(i & 0x40))
 				w83781d_write_value(client, W83781D_REG_IRQ,
 						    i | 0x40);
-
-			for(i = 0; i < 3; i++)
-				data->pwmenable[i] = 1;
 		}
 	}
 
@@ -1442,20 +1439,22 @@ static void w83781d_update_client(struct i2c_client *client)
                                               W83781D_REG_FAN_MIN(i));
                        if (data->type != w83791d && i == 3) break;
                }
-               if (data->type != w83781d) {
+               if (data->type != w83781d && data->type != as99127f) {
                        for (i = 1; i <= 4; i++) {
                                data->pwm[i - 1] =
                                    w83781d_read_value(client,
 				             W83781D_REG_PWM(data->type, i));
                                if (((data->type == w83783s)
                                     || (data->type == w83627hf)
-                                    || (data->type == as99127f)
                                     || (data->type == w83697hf)
                                     || ((data->type == w83782d)
                                        && i2c_is_isa_client(client)))
                                    && i == 2)
                                        break;
                        }
+			/* Only PWM2 can be disabled */
+			data->pwmenable[1] = (w83781d_read_value(client,
+					      W83781D_REG_PWMCLK12) & 0x08) >> 3;
                }
 
                data->temp = w83781d_read_value(client, W83781D_REG_TEMP);