iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 72 insertions, 0 deletions

diff --git a/include/net/ncsi.h b/include/net/ncsi.h
new file mode 100644
index 000000000..e88635820
--- /dev/null
+++ b/include/net/ncsi.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_NCSI_H
+#define __NET_NCSI_H
+
+#include <linux/types.h>
+
+/*
+ * The NCSI device states seen from external. More NCSI device states are
+ * only visible internally (in net/ncsi/internal.h). When the NCSI device
+ * is registered, it's in ncsi_dev_state_registered state. The state
+ * ncsi_dev_state_start is used to drive to choose active package and
+ * channel. After that, its state is changed to ncsi_dev_state_functional.
+ *
+ * The state ncsi_dev_state_stop helps to shut down the currently active
+ * package and channel while ncsi_dev_state_config helps to reconfigure
+ * them.
+ */
+enum {
+	ncsi_dev_state_registered	= 0x0000,
+	ncsi_dev_state_functional	= 0x0100,
+	ncsi_dev_state_probe		= 0x0200,
+	ncsi_dev_state_config		= 0x0300,
+	ncsi_dev_state_suspend		= 0x0400,
+};
+
+struct ncsi_dev {
+	int               state;
+	int		  link_up;
+	struct net_device *dev;
+	void		  (*handler)(struct ncsi_dev *ndev);
+};
+
+#ifdef CONFIG_NET_NCSI
+int ncsi_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid);
+int ncsi_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, u16 vid);
+struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
+				   void (*notifier)(struct ncsi_dev *nd));
+int ncsi_start_dev(struct ncsi_dev *nd);
+void ncsi_stop_dev(struct ncsi_dev *nd);
+void ncsi_unregister_dev(struct ncsi_dev *nd);
+#else /* !CONFIG_NET_NCSI */
+static inline int ncsi_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)
+{
+	return -EINVAL;
+}
+
+static inline int ncsi_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, u16 vid)
+{
+	return -EINVAL;
+}
+
+static inline struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
+					void (*notifier)(struct ncsi_dev *nd))
+{
+	return NULL;
+}
+
+static inline int ncsi_start_dev(struct ncsi_dev *nd)
+{
+	return -ENOTTY;
+}
+
+static inline void ncsi_stop_dev(struct ncsi_dev *nd)
+{
+}
+
+static inline void ncsi_unregister_dev(struct ncsi_dev *nd)
+{
+}
+#endif /* CONFIG_NET_NCSI */
+
+#endif /* __NET_NCSI_H */