add force_subclients parameter which allows moving subclients

to different addresses; this allows initialization of two
      clients on the same i2c bus by preventing subclient address
      conflicts at 0x48 and 0x49.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@1312 7894878c-1315-0410-8ee3-d5d059ff63e0

doc/chips/MODPARMS

@@ -3,15 +3,16 @@ Parameters for modprobe and insmod
 ==================================
 SUMMARY
 
-	[modprobe,insmod] module [parameter...]
+	[modprobe,insmod] module {parameter...}
 	Parameters:
-		force=bus,address
-		force_addr=address
-		force_[chipname]=bus,address
-		ignore=bus,address
-		ignore_range=bus,startaddress,endaddress
-		probe=bus,address
-		probe_range=bus,startaddress,endaddress
+		force=bus,address{,bus,address}
+		force_addr=address{,address}
+		force_[chipname]=bus,address{,bus,address}
+		force_subclients=bus,caddr,saddr,saddr
+		ignore=bus,address{,bus,address}
+		ignore_range=bus,start,end{,bus,start,end}
+		probe=bus,address{,bus,address}
+		probe_range=bus,start,end{,bus,start,end}
 		init=[0,1] (default 1)
 
 	All arguments are in decimal unless prefixed by "0x".
@@ -89,11 +90,19 @@ very strange results...
 It is used to program the base address of the sensor registers.
 This is required if the BIOS does not initialize the base address.
 
+`force_subclients' is used to force the i2c addresses for subclients of
+a certain chip. Typical usage is `force_subclients=0,0x2d,0x4a,0x4b'
+to force the subclients of chip 0x2d on bus 0 to i2c addresses
+0x4a and 0x4b.
+This parameter is currently supported only by the w83781d driver
+and is useful for certain Tyan boards.
+
 `init' is used to tell a driver to bypass initializing a chip.
 This may be necessary if the BIOS has initialized the chip a certain way
 and the driver should not overwrite that initialization.
+It is also useful if normal initialization crashes the system.
 The default is 1, so the only useful value is `init=0'.
-This parameter is not supported by most drivers.
+This parameter is currently supported only by the w83781d driver.
 
 ==================================
 EXAMPLE

doc/chips/w83781d

@@ -54,8 +54,16 @@ Module Parameters
   Ditto
 * force_w83627hf:
   Ditto
+* force_w83697hf:
+  Ditto
 * force_as99127f:
   Ditto
+* force_subclients=bus,caddr,saddr,saddr
+  This is used to force the i2c addresses for subclients of
+  a certain chip. Typical usage is `force_subclients=0,0x2d,0x4a,0x4b'
+  to force the subclients of chip 0x2d on bus 0 to i2c addresses
+  0x4a and 0x4b.
+  This parameter is useful for certain Tyan boards.
 * ignore: short array (min = 1, max = 48)
   List of adapter,address pairs not to scan
 * ignore_range: short array (min = 1, max = 48)

kernel/chips/w83781d.c

@@ -67,6 +67,8 @@ static unsigned int normal_isa_range[] = { SENSORS_ISA_END };
 
 /* Insmod parameters */
 SENSORS_INSMOD_6(w83781d, w83782d, w83783s, w83627hf, as99127f, w83697hf);
+SENSORS_MODULE_PARM(force_subclients, "List of subclient addresses: " \
+                      "{bus, clientaddr, subclientaddr1, subclientaddr2}");
 
 static int init = 1;
 MODULE_PARM(init, "i");
@@ -747,7 +749,7 @@ int w83781d_attach_adapter(struct i2c_adapter *adapter)
 int w83781d_detect(struct i2c_adapter *adapter, int address,
 		   unsigned short flags, int kind)
 {
-	int i, val1, val2;
+	int i, val1, val2, id;
 	struct i2c_client *new_client;
 	struct w83781d_data *data;
 	int err = 0;
@@ -929,11 +931,33 @@ int w83781d_detect(struct i2c_adapter *adapter, int address,
 			err = -ENOMEM;
 			goto ERROR4;
 		}
-		val1 = w83781d_read_value(new_client,
-				          W83781D_REG_I2C_SUBADDR);
-		data->lm75[0].addr = 0x48 + (val1 & 0x07);
+		id = i2c_adapter_id(adapter);
+		if(force_subclients[0] == id && force_subclients[1] == address) {
+			for(i = 2; i <= 3; i++) {
+				if(force_subclients[i] < 0x48 ||
+				   force_subclients[i] > 0x4f) {
+					printk(KERN_ERR "w83781d.o: Invalid subclient address %d; must be 0x48-0x4f\n",
+					        force_subclients[i]);
+					goto ERROR5;
+				}
+			}
+			w83781d_write_value(new_client,
+			                    W83781D_REG_I2C_SUBADDR,
+			                    (force_subclients[2] & 0x07) |
+			                    ((force_subclients[3] & 0x07) <<4));
+			data->lm75[0].addr = force_subclients[2];
+		} else {
+			val1 = w83781d_read_value(new_client,
+					          W83781D_REG_I2C_SUBADDR);
+			data->lm75[0].addr = 0x48 + (val1 & 0x07);
+		}
 		if (kind != w83783s) {
-			data->lm75[1].addr = 0x48 + ((val1 >> 4) & 0x07);
+			if(force_subclients[0] == id &&
+			   force_subclients[1] == address) {
+				data->lm75[1].addr = force_subclients[3];
+			} else {
+				data->lm75[1].addr = 0x48 + ((val1 >> 4) & 0x07);
+			}
 			if(data->lm75[0].addr == data->lm75[1].addr) {
 				printk(KERN_ERR "w83781d.o: Duplicate addresses 0x%x for subclients.\n",
 					data->lm75[0].addr);
@@ -963,8 +987,7 @@ int w83781d_detect(struct i2c_adapter *adapter, int address,
 				       i, data->lm75[i].addr);
 				if (i == 1)
 					goto ERROR6;
-				else
-					goto ERROR5;
+				goto ERROR5;
 			}
 			if (kind == w83783s)
 				break;
@@ -993,7 +1016,7 @@ int w83781d_detect(struct i2c_adapter *adapter, int address,
 	}
 	data->sysctl_id = i;
 
-	/* Initialize the Winbond chip */
+	/* Initialize the chip */
 	w83781d_init_client(new_client);
 	return 0;