From: Matrix Screen Controller maintainers
Subject: [PATCH] regulator: axp20x: accept absent DCDC frequency on AXP313A

The vendor 6.1.31 tree contains an early AXP313A implementation which
requires dcdcfreq to equal 3000000.  The parser passes zero when the
x-powers,dcdc-freq property is absent, so that implementation rejects the
valid binding and logs -EINVAL during every boot.

AXP313A has a fixed 3 MHz switching frequency and the upstream binding
disallows the property.  Match the final upstream behaviour: accept the
zero value representing an absent property and reject any configured value.

---
 drivers/regulator/axp20x-regulator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -1090,7 +1090,7 @@ static int axp20x_set_dcdc_freq(struct platform_device *pdev, u32 dcdcfreq)
 	case AXP313A_ID:
 		/* The DCDC PWM frequency seems to be fixed to 3 MHz. */
-		if (dcdcfreq != 3000000) {
+		if (dcdcfreq != 0) {
 			dev_err(&pdev->dev,
 				"DCDC frequency on AXP313a is fixed to 3 MHz.\n");
 			return -EINVAL;
 		}
-- 
2.39.2