rtc: pcf8563: fix incorrect maximum clock rate handling

[ Upstream commit 906726a ]

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: a39a640 ("rtc: pcf8563: add CLKOUT to common clock framework")
Signed-off-by: Brian Masney <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: masneyb

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,