From: Johan Hovold <jhovold@gmail.com>
Date: Tue, 22 Oct 2013 16:32:39 +0000 (+0200)
Subject: misc: atmel_pwm: add deferred-probing support
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ccd24ec4c98c1aa76e73d4fa80bf8146b5e62175;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

misc: atmel_pwm: add deferred-probing support

commit 5c6d6fd1564138ad048564e48639f842714a90c6 upstream.

Two drivers (atmel-pwm-bl and leds-atmel-pwm) currently depend on the
atmel_pwm driver to have bound to any pwm-device before their devices
are probed.

Support deferred probing of such devices by making sure to return
-EPROBE_DEFER from pwm_channel_alloc when no pwm-device has yet been
bound.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
index 494d0500bda..a6dc56e1bc5 100644
--- a/drivers/misc/atmel_pwm.c
+++ b/drivers/misc/atmel_pwm.c
@@ -90,8 +90,10 @@ int pwm_channel_alloc(int index, struct pwm_channel *ch)
 	unsigned long	flags;
 	int		status = 0;
 
-	/* insist on PWM init, with this signal pinned out */
-	if (!pwm || !(pwm->mask & 1 << index))
+	if (!pwm)
+		return -EPROBE_DEFER;
+
+	if (!(pwm->mask & 1 << index))
 		return -ENODEV;
 
 	if (index < 0 || index >= PWM_NCHAN || !ch)