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, 25 insertions, 0 deletions

diff --git a/lib/notifier-error-inject.h b/lib/notifier-error-inject.h
new file mode 100644
index 000000000..fafff5f2a
--- /dev/null
+++ b/lib/notifier-error-inject.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/atomic.h>
+#include <linux/debugfs.h>
+#include <linux/notifier.h>
+
+struct notifier_err_inject_action {
+	unsigned long val;
+	int error;
+	const char *name;
+};
+
+#define NOTIFIER_ERR_INJECT_ACTION(action)	\
+	.name = #action, .val = (action),
+
+struct notifier_err_inject {
+	struct notifier_block nb;
+	struct notifier_err_inject_action actions[];
+	/* The last slot must be terminated with zero sentinel */
+};
+
+extern struct dentry *notifier_err_inject_dir;
+
+extern struct dentry *notifier_err_inject_init(const char *name,
+		struct dentry *parent, struct notifier_err_inject *err_inject,
+		int priority);