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, 114 insertions, 0 deletions

diff --git a/drivers/base/module.c b/drivers/base/module.c
new file mode 100644
index 000000000..6789dca48
--- /dev/null
+++ b/drivers/base/module.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * module.c - module sysfs fun for drivers
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include "base.h"
+
+static char *make_driver_name(const struct device_driver *drv)
+{
+	char *driver_name;
+
+	driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);
+	if (!driver_name)
+		return NULL;
+
+	return driver_name;
+}
+
+static void module_create_drivers_dir(struct module_kobject *mk)
+{
+	static DEFINE_MUTEX(drivers_dir_mutex);
+
+	mutex_lock(&drivers_dir_mutex);
+	if (mk && !mk->drivers_dir)
+		mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
+	mutex_unlock(&drivers_dir_mutex);
+}
+
+int module_add_driver(struct module *mod, const struct device_driver *drv)
+{
+	char *driver_name;
+	struct module_kobject *mk = NULL;
+	int ret;
+
+	if (!drv)
+		return 0;
+
+	if (mod)
+		mk = &mod->mkobj;
+	else if (drv->mod_name) {
+		/* Lookup or create built-in module entry in /sys/module */
+		mk = lookup_or_create_module_kobject(drv->mod_name);
+		if (mk) {
+			/* remember our module structure */
+			drv->p->mkobj = mk;
+			/* lookup_or_create_module_kobject took a reference */
+			kobject_put(&mk->kobj);
+		}
+	}
+
+	if (!mk)
+		return 0;
+
+	ret = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
+	if (ret)
+		return ret;
+
+	driver_name = make_driver_name(drv);
+	if (!driver_name) {
+		ret = -ENOMEM;
+		goto out_remove_kobj;
+	}
+
+	module_create_drivers_dir(mk);
+	if (!mk->drivers_dir) {
+		ret = -EINVAL;
+		goto out_free_driver_name;
+	}
+
+	ret = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
+	if (ret)
+		goto out_remove_drivers_dir;
+
+	kfree(driver_name);
+
+	return 0;
+
+out_remove_drivers_dir:
+	sysfs_remove_link(mk->drivers_dir, driver_name);
+
+out_free_driver_name:
+	kfree(driver_name);
+
+out_remove_kobj:
+	sysfs_remove_link(&drv->p->kobj, "module");
+	return ret;
+}
+
+void module_remove_driver(const struct device_driver *drv)
+{
+	struct module_kobject *mk = NULL;
+	char *driver_name;
+
+	if (!drv)
+		return;
+
+	sysfs_remove_link(&drv->p->kobj, "module");
+
+	if (drv->owner)
+		mk = &drv->owner->mkobj;
+	else if (drv->p->mkobj)
+		mk = drv->p->mkobj;
+	if (mk && mk->drivers_dir) {
+		driver_name = make_driver_name(drv);
+		if (driver_name) {
+			sysfs_remove_link(mk->drivers_dir, driver_name);
+			kfree(driver_name);
+		}
+	}
+}