summary refs log tree commit diff
path: root/drivers/rtc
diff options
context:
space:
mode:
authorTroy Kisky <troy.kisky@boundarydevices.com>2017-11-02 18:58:13 -0700
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2017-11-08 07:52:23 +0100
commitc8384bb04261b9d32fe7402a6068ddaf38913b23 (patch)
tree3d587883486b42b4b82847b806d0b9cf87748d4e /drivers/rtc
parentde6042d2fa8afe22b76e3c68fd6e9584c9415a3b (diff)
downloadlinux-c8384bb04261b9d32fe7402a6068ddaf38913b23.tar.gz
rtc: m41t80: fix m41t80_sqw_round_rate return value
Previously it was returning the best of
32768, 8192, 1024, 64, 2, 0

Now, best of
32768, 8192, 4096, 2048, 1024, 512, 256, 128,
64, 32, 16, 8, 4, 2, 1, 0

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-m41t80.c19
1 files changed, 7 insertions, 12 deletions
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 8f5843169dc2..42fc735a5446 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -468,18 +468,13 @@ static unsigned long m41t80_sqw_recalc_rate(struct clk_hw *hw,
 static long m41t80_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
 				  unsigned long *prate)
 {
-	int i, freq = M41T80_SQW_MAX_FREQ;
-
-	if (freq <= rate)
-		return freq;
-
-	for (i = 2; i <= ilog2(M41T80_SQW_MAX_FREQ); i++) {
-		freq /= 1 << i;
-		if (freq <= rate)
-			return freq;
-	}
-
-	return 0;
+	if (rate >= M41T80_SQW_MAX_FREQ)
+		return M41T80_SQW_MAX_FREQ;
+	if (rate >= M41T80_SQW_MAX_FREQ / 4)
+		return M41T80_SQW_MAX_FREQ / 4;
+	if (!rate)
+		return 0;
+	return 1 << ilog2(rate);
 }
 
 static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate,