rtc: ds1307: fix incorrect maximum clock rate handling

[ Upstream commit cf6eb547a24af7ad7bbd2abe9c5327f956bbeae8 ]

When ds3231_clk_sqw_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: 6c6ff145b3346 ("rtc: ds1307: add clock provider support for DS3231")
Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20250710-rtc-clk-round-rate-v1-1-33140bb2278e@redhat.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 5efbe69bf5ca8cbc2a325cf2797afcd14f3760bf..c8a666de9cbe9163ab7e112b01b99d97c94970d3 100644 (file)
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -1466,7 +1466,7 @@ static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
                        return ds3231_clk_sqw_rates[i];
        }
 
-       return 0;
+       return ds3231_clk_sqw_rates[ARRAY_SIZE(ds3231_clk_sqw_rates) - 1];
 }
 
 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,