[PATCH] I2C: w83781d fan_div code refactoring

Quoting myself:

> This tends to increase the size of the three set_store_regs_fan_div
> functions, and I am considering refactoring them at some point. Later
> though.

Here is the promised refactoring. Tested on my AS99127F rev.1, seems to
work. As for the previous patch, there is a part that I cannot test with
the AS99127F, so additional testing is welcome.

I agree this makes the code slightly less readable, but this saves 60
lines of code (1754 bytes, around 3% of the driver total), and is
actually far less complex that I first feared.

drivers/i2c/chips/w83781d.c

@@ -620,7 +620,7 @@ show_fan_div_reg(struct device *dev, char *buf, int nr)
    least suprise; the user doesn't expect the fan minimum to change just
    because the divisor changed. */
 static ssize_t
-store_regs_fan_div_1(struct device *dev, const char *buf, size_t count)
+store_fan_div_reg(struct device *dev, const char *buf, size_t count, int nr)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct w83781d_data *data = i2c_get_clientdata(client);
@@ -628,92 +628,28 @@ store_regs_fan_div_1(struct device *dev, const char *buf, size_t count)
 	u8 reg;
 
 	/* Save fan_min */
-	min = FAN_FROM_REG(data->fan_min[0],
-			   DIV_FROM_REG(data->fan_div[0]));
+	min = FAN_FROM_REG(data->fan_min[nr],
+			   DIV_FROM_REG(data->fan_div[nr]));
 
-	data->fan_div[0] = DIV_TO_REG(simple_strtoul(buf, NULL, 10),
+	data->fan_div[nr] = DIV_TO_REG(simple_strtoul(buf, NULL, 10),
 				      data->type);
 
-	reg = w83781d_read_value(client, W83781D_REG_VID_FANDIV) & 0xcf;
-	reg |= (data->fan_div[0] & 0x03) << 4;
-	w83781d_write_value(client, W83781D_REG_VID_FANDIV, reg);
+	reg = (w83781d_read_value(client, nr==2 ? W83781D_REG_PIN : W83781D_REG_VID_FANDIV)
+	       & (nr==0 ? 0xcf : 0x3f))
+	    | ((data->fan_div[nr] & 0x03) << (nr==0 ? 4 : 6));
+	w83781d_write_value(client, nr==2 ? W83781D_REG_PIN : W83781D_REG_VID_FANDIV, reg);
 
 	/* w83781d and as99127f don't have extended divisor bits */
 	if (data->type != w83781d && data->type != as99127f) {
-		reg = w83781d_read_value(client, W83781D_REG_VBAT) & 0xdf;
-		reg |= (data->fan_div[0] & 0x04) << 3;
+		reg = (w83781d_read_value(client, W83781D_REG_VBAT)
+		       & ~(1 << (5 + nr)))
+		    | ((data->fan_div[nr] & 0x04) << (3 + nr));
 		w83781d_write_value(client, W83781D_REG_VBAT, reg);
 	}
 
 	/* Restore fan_min */
-	data->fan_min[0] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[0]));
-	w83781d_write_value(client, W83781D_REG_FAN_MIN(1), data->fan_min[0]);
-
-	return count;
-}
-
-static ssize_t
-store_regs_fan_div_2(struct device *dev, const char *buf, size_t count)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	struct w83781d_data *data = i2c_get_clientdata(client);
-	unsigned long min;
-	u8 reg;
-
-	/* Save fan_min */
-	min = FAN_FROM_REG(data->fan_min[1],
-			   DIV_FROM_REG(data->fan_div[1]));
-
-	data->fan_div[1] = DIV_TO_REG(simple_strtoul(buf, NULL, 10),
-				      data->type);
-
-	reg = w83781d_read_value(client, W83781D_REG_VID_FANDIV) & 0x3f;
-	reg |= (data->fan_div[1] & 0x03) << 6;
-	w83781d_write_value(client, W83781D_REG_VID_FANDIV, reg);
-
-	/* w83781d and as99127f don't have extended divisor bits */
-	if (data->type != w83781d && data->type != as99127f) {
-		reg = w83781d_read_value(client, W83781D_REG_VBAT) & 0xbf;
-		reg |= (data->fan_div[1] & 0x04) << 4;
-		w83781d_write_value(client, W83781D_REG_VBAT, reg);
-	}
-
-	/* Restore fan_min */
-	data->fan_min[1] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[1]));
-	w83781d_write_value(client, W83781D_REG_FAN_MIN(2), data->fan_min[1]);
-
-	return count;
-}
-
-static ssize_t
-store_regs_fan_div_3(struct device *dev, const char *buf, size_t count)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	struct w83781d_data *data = i2c_get_clientdata(client);
-	unsigned long min;
-	u8 reg;
-
-	/* Save fan_min */
-	min = FAN_FROM_REG(data->fan_min[2],
-			   DIV_FROM_REG(data->fan_div[2]));
-
-	data->fan_div[2] = DIV_TO_REG(simple_strtoul(buf, NULL, 10),
-				      data->type);
-
-	reg = w83781d_read_value(client, W83781D_REG_PIN) & 0x3f;
-	reg |= (data->fan_div[2] & 0x03) << 6;
-	w83781d_write_value(client, W83781D_REG_PIN, reg);
-
-	/* w83781d and as99127f don't have extended divisor bits */
-	if (data->type != w83781d && data->type != as99127f) {
-		reg = w83781d_read_value(client, W83781D_REG_VBAT) & 0x7f;
-		reg |= (data->fan_div[2] & 0x04) << 5;
-		w83781d_write_value(client, W83781D_REG_VBAT, reg);
-	}
-
-	/* Restore fan_min */
-	data->fan_min[2] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[2]));
-	w83781d_write_value(client, W83781D_REG_FAN_MIN(3), data->fan_min[2]);
+	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
+	w83781d_write_value(client, W83781D_REG_FAN_MIN(nr+1), data->fan_min[nr]);
 
 	return count;
 }
@@ -723,6 +659,10 @@ static ssize_t show_regs_fan_div_##offset (struct device *dev, char *buf) \
 { \
 	return show_fan_div_reg(dev, buf, offset); \
 } \
+static ssize_t store_regs_fan_div_##offset (struct device *dev, const char *buf, size_t count) \
+{ \
+	return store_fan_div_reg(dev, buf, count, offset - 1); \
+} \
 static DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, show_regs_fan_div_##offset, store_regs_fan_div_##offset)
 
 sysfs_fan_div(1);