[PATCH 1/2] misc: atmel_pwm: add deferred-probing support

From: Johan Hovold
Date: Tue Oct 22 2013 - 12:33:43 EST


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@xxxxxxxxx>
---
drivers/misc/atmel_pwm.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
index 494d050..a6dc56e 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)
--
1.8.4

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