From 3b442c60cf9766c76bc3c1e44e3e387853074a08 Mon Sep 17 00:00:00 2001
From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Tue, 30 Jul 2019 14:32:29 +0200
Subject: pwm: jz4740: Document known limitations
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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>
---
 drivers/pwm/pwm-jz4740.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'drivers/pwm')

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>
-- 
cgit