[PATCH 1/4] phy: zynqmp: Allow variation in refclk rate

[Sean Anderson]

From: Sean Anderson <sean.anderson at seco.com>

Due to limited available frequency ratios, the reference clock rate may
not be exactly the same as the required rate. Allow a small (100 ppm)
deviation.

Signed-off-by: Sean Anderson <sean.anderson at seco.com>
Link: https://lore.kernel.org/r/20230711194542.898230-1-sean.anderson@seco.com
Signed-off-by: Vinod Koul <vkoul at kernel.org>
[ Linux commit 76009ee76e05e30e29aade02e788aebe9ce9ffd2 ]
Signed-off-by: Sean Anderson <sean.anderson at linux.dev>
---

 drivers/phy/phy-zynqmp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/phy-zynqmp.c b/drivers/phy/phy-zynqmp.c
index 9649e660220..7151402666b 100644
--- a/drivers/phy/phy-zynqmp.c
+++ b/drivers/phy/phy-zynqmp.c
@@ -725,7 +725,10 @@ static int xpsgtr_get_ref_clocks(struct udevice *dev)
 		}
 
 		for (i = 0 ; i < ARRAY_SIZE(ssc_lookup); i++) {
-			if (rate == ssc_lookup[i].refclk_rate) {
+			/* Allow an error of 100 ppm */
+			unsigned long error = ssc_lookup[i].refclk_rate / 10000;
+
+			if (abs(rate - ssc_lookup[i].refclk_rate) < error) {
 				gtr_dev->refclk_sscs[refclk] = &ssc_lookup[i];
 				dev_dbg(dev, "Found rate %d\n", i);
 				break;
-- 
2.35.1.1320.gc452695387.dirty