linux-kernel - [PATCH 05/15] rtc: pcf8563: fix incorrect maximum clock rate handling

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Message-Id: <20250710-rtc-clk-round-rate-v1-5-33140bb2278e@redhat.com>
Date: Thu, 10 Jul 2025 11:20:25 -0400
From: Brian Masney <bmasney@...hat.com>
To: Alexandre Belloni <alexandre.belloni@...tlin.com>, 
 Akinobu Mita <akinobu.mita@...il.com>, 
 Michael Turquette <mturquette@...libre.com>, 
 Heiko Stuebner <heiko@...ech.de>, Andrew Morton <akpm@...ux-foundation.org>, 
 Avi Fishman <avifishman70@...il.com>, Tomer Maimon <tmaimon77@...il.com>, 
 Tali Perry <tali.perry1@...il.com>, Patrick Venture <venture@...gle.com>, 
 Nancy Yuen <yuenn@...gle.com>, Benjamin Fair <benjaminfair@...gle.com>, 
 Mia Lin <mimi05633@...il.com>, 
 Michael McCormick <michael.mccormick@...tel.net>, 
 Heiko Schocher <hs@...x.de>, Parthiban Nallathambi <pn@...x.de>, 
 Antoniu Miclaus <antoniu.miclaus@...log.com>, 
 Maxime Ripard <mripard@...nel.org>, Stephen Boyd <sboyd@...nel.org>
Cc: linux-clk@...r.kernel.org, linux-rtc@...r.kernel.org, 
 linux-kernel@...r.kernel.org, openbmc@...ts.ozlabs.org, 
 Brian Masney <bmasney@...hat.com>
Subject: [PATCH 05/15] rtc: pcf8563: fix incorrect maximum clock rate
 handling

When pcf8563_clkout_round_rate() is called with a requested rate higher
than the highest supported rate, it currently returns 0, which disables
the clock. According to the clk API, round_rate() should instead return
the highest supported rate. Update the function to return the maximum
supported rate in this case.

Fixes: a39a6405d5f94 ("rtc: pcf8563: add CLKOUT to common clock framework")
Signed-off-by: Brian Masney <bmasney@...hat.com>
---
 drivers/rtc/rtc-pcf8563.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index b2611697fa5e3adc61f687e39385d10736dec677..a2a2067b28a127bafec66328cd75f50aa4277986 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -339,7 +339,7 @@ static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 		if (clkout_rates[i] <= rate)
 			return clkout_rates[i];
 
-	return 0;
+	return clkout_rates[0];
 }
 
 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,

-- 
2.50.0