[PATCH v9 04/25] clk: Mention that .recalc_rate can return 0 on error

From: Maxime Ripard <maxime@cerno.tech>
To: Mike Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	linux-clk@vger.kernel.org
Cc: Jerome Brunet <jbrunet@baylibre.com>,
	Naresh Kamboju <naresh.kamboju@linaro.org>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Alexander Stein <alexander.stein@ew.tq-group.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Yassine Oudjana <y.oudjana@protonmail.com>,
	Tony Lindgren <tony@atomide.com>,
	Maxime Ripard <maxime@cerno.tech>
Subject: [PATCH v9 04/25] clk: Mention that .recalc_rate can return 0 on error
Date: Tue, 16 Aug 2022 13:25:09 +0200	[thread overview]
Message-ID: <20220816112530.1837489-5-maxime@cerno.tech> (raw)
In-Reply-To: <20220816112530.1837489-1-maxime@cerno.tech>

Multiple platforms (amlogic, imx8) return 0 when the clock rate cannot
be determined properly by the recalc_rate hook. Mention in the
documentation that the framework is ok with that.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 include/linux/clk-provider.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 1615010aa0ec..9a14cfa0d201 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -118,8 +118,9 @@ struct clk_duty {
  *
  * @recalc_rate	Recalculate the rate of this clock, by querying hardware. The
  *		parent rate is an input parameter.  It is up to the caller to
- *		ensure that the prepare_mutex is held across this call.
- *		Returns the calculated rate.  Optional, but recommended - if
+ *		ensure that the prepare_mutex is held across this call. If the
+ *		driver cannot figure out a rate for this clock, it must return
+ *		0. Returns the calculated rate. Optional, but recommended - if
  *		this op is not set then clock rate will be initialized to 0.
  *
  * @round_rate:	Given a target rate as input, returns the closest rate actually
-- 
2.37.1

