[RESEND][PATCH] pwm: Set class for exported channels in sysfs

Notifications for devices without bus or class set get dropped by
dev_uevent_filter. Adding the class to the exported child matches
what the gpio subsystem is doing.

With this change exporting a channel triggers a udev event, which
gives userspace a chance to fixup permissions and makes it possible
for non-root users to make use of the pwm subsystem.

Signed-off-by: Gottfried Haider <redacted>
CC: Thierry Reding <redacted>
CC: H Hartley Sweeten <hsweeten@visionengravers.com>
CC: linux-pwm at vger.kernel.org
CC: linux-arm-kernel at lists.infradead.org
CC: linux-rpi-kernel at lists.infradead.org
---
 drivers/pwm/sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index a813239..83f2b0b 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c

@@ -263,6 +263,7 @@ static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
        export->pwm = pwm;
        mutex_init(&export->lock);

+       export->child.class = parent->class;
        export->child.release = pwm_export_release;
        export->child.parent = parent;
        export->child.devt = MKDEV(0, 0);