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authorJohan Hovold <jhovold@gmail.com>2013-10-22 18:32:39 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-29 16:22:57 -0700
commit5c6d6fd1564138ad048564e48639f842714a90c6 (patch)
tree038450eadd2c1b1545dc75cc2c06202019f3c09f /drivers/misc
parent50f67a06713599e18cd9141e413d0e2653bb242b (diff)
downloadlinux-5c6d6fd1564138ad048564e48639f842714a90c6.tar.gz
misc: atmel_pwm: add deferred-probing support
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>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/atmel_pwm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
index 494d0500bda6..a6dc56e1bc58 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)