[PATCH v3 1/4] hwmon: iio_hwmon: delay probing with late_initcall

Quentin Schulz
2016-07-26T07:43:44Z

iio_channel_get_all returns -ENODEV when it cannot find either phandles and
properties in the Device Tree or channels whose consumer_dev_name matches
iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers
which might be probed after iio_hwmon.

This makes sure iio_hwmon is probed after all iio drivers which provides
channels to iio_hwmon are probed, be they present in the DT or using
iio_map_list.

This replaces module_platform_driver() by an explicit code variant which
calls late_initcall() install of module_init(), meaning it probes after
all the drivers using module_init() as their init.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
---

v3:
- use late_initcall instead of deferring probe,

drivers/hwmon/iio_hwmon.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
index b550ba5..0a00bfb 100644
--- a/drivers/hwmon/iio_hwmon.c
+++ b/drivers/hwmon/iio_hwmon.c
@@ -192,7 +192,21 @@ static struct platform_driver __refdata iio_hwmon_driver = {
.remove = iio_hwmon_remove,
};

-module_platform_driver(iio_hwmon_driver);
+static struct platform_driver * const drivers[] = {
+ &iio_hwmon_driver,
+};
+
+static int __init iio_hwmon_late_init(void)
+{
+ return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
+}
+late_initcall(iio_hwmon_late_init);
+
+static void __exit iio_hwmon_exit(void)
+{
+ platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
+}
+module_exit(iio_hwmon_exit);

MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO to hwmon driver");
--
2.5.0