staging:iio:ade7854: Fix error handling on read/write

The original code does not correctly handle the error related to I2C
read and write. This patch fixes the error handling related to all
read/write functions for I2C.

Signed-off-by: John Syne <john3909@gmail.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Fixes: 8d97a5877 ("staging: iio: meter: new driver for ADE7754 devices")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/meter/ade7854-i2c.c

@@ -31,7 +31,7 @@ static int ade7854_i2c_write_reg_8(struct device *dev,
 	ret = i2c_master_send(st->i2c, st->tx, 3);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_16(struct device *dev,
@@ -51,7 +51,7 @@ static int ade7854_i2c_write_reg_16(struct device *dev,
 	ret = i2c_master_send(st->i2c, st->tx, 4);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_24(struct device *dev,
@@ -72,7 +72,7 @@ static int ade7854_i2c_write_reg_24(struct device *dev,
 	ret = i2c_master_send(st->i2c, st->tx, 5);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_write_reg_32(struct device *dev,
@@ -94,7 +94,7 @@ static int ade7854_i2c_write_reg_32(struct device *dev,
 	ret = i2c_master_send(st->i2c, st->tx, 6);
 	mutex_unlock(&st->buf_lock);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static int ade7854_i2c_read_reg_8(struct device *dev,
@@ -110,11 +110,11 @@ static int ade7854_i2c_read_reg_8(struct device *dev,
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 1);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = st->rx[0];
@@ -136,11 +136,11 @@ static int ade7854_i2c_read_reg_16(struct device *dev,
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 8) | st->rx[1];
@@ -162,11 +162,11 @@ static int ade7854_i2c_read_reg_24(struct device *dev,
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 3);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 16) | (st->rx[1] << 8) | st->rx[2];
@@ -188,11 +188,11 @@ static int ade7854_i2c_read_reg_32(struct device *dev,
 	st->tx[1] = reg_address & 0xFF;
 
 	ret = i2c_master_send(st->i2c, st->tx, 2);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	ret = i2c_master_recv(st->i2c, st->rx, 3);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
 	*val = (st->rx[0] << 24) | (st->rx[1] << 16) |

drivers/staging/iio/meter/ade7854.c

@@ -33,7 +33,7 @@ static ssize_t ade7854_read_8bit(struct device *dev,
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_8(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -50,7 +50,7 @@ static ssize_t ade7854_read_16bit(struct device *dev,
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_16(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -67,7 +67,7 @@ static ssize_t ade7854_read_24bit(struct device *dev,
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
 	ret = st->read_reg_24(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -84,7 +84,7 @@ static ssize_t ade7854_read_32bit(struct device *dev,
 	struct ade7854_state *st = iio_priv(indio_dev);
 
 	ret = st->read_reg_32(dev, this_attr->address, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	return sprintf(buf, "%u\n", val);
@@ -416,7 +416,7 @@ static int ade7854_set_irq(struct device *dev, bool enable)
 	u32 irqen;
 
 	ret = st->read_reg_32(dev, ADE7854_MASK0, &irqen);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	if (enable)