[PATCH] phy: zynqmp: Allow variation in refclk rate

From: Sean Anderson
Date: Tue Jul 11 2023 - 15:46:17 EST


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@xxxxxxxx>
---

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

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index b0c2045b886e..2559c6594cea 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -904,7 +904,10 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
rate = clk_get_rate(clk);

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];
break;
}
--
2.35.1.1320.gc452695387.dirty