rtc: ds1307: fix incorrect maximum clock rate handling

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>

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index ce0994d9219a29b4cd119ed390d32deadc5651da..1960d1bd851cb09e13db3dda53628e2136f8773b 100644 (file)
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -1477,7 +1477,7 @@ 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,