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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2019-07-30 15:32:29 +0300
committerThierry Reding <thierry.reding@gmail.com>2019-09-21 01:55:33 +0300
commit3b442c60cf9766c76bc3c1e44e3e387853074a08 (patch)
tree03bc88aae1a0ca699510d24e9d7611119586ebea /drivers/pwm
parentf6abac0379b8368519f28016c8c8821b8bd17f5e (diff)
downloadlinux-3b442c60cf9766c76bc3c1e44e3e387853074a08.tar.xz
pwm: jz4740: Document known limitations
The JZ4740 PWM implementation doesn't fulfill the (up to now insufficiently documented) requirements of the PWM API. At least document them in the driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-jz4740.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index f901e8a0d33d..9d444d012f92 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -2,6 +2,11 @@
/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 platform PWM support
+ *
+ * Limitations:
+ * - The .apply callback doesn't complete the currently running period before
+ * reconfiguring the hardware.
+ * - Each period starts with the inactive part.
*/
#include <linux/clk.h>