[PATCH 3/4] usb: dwc3-am62: Fix PHY core voltage selection

Roger Quadros
2024-02-01T12:12:34Z

TRM information is outdated and design team has confirmed
that PHY_CORE_VOLTAGE should be 0 irrespective of
VDD_CORE voltage.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
---
drivers/usb/dwc3/dwc3-am62.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c
index 600ba9cfefea..af1ce934e7fb 100644
--- a/drivers/usb/dwc3/dwc3-am62.c
+++ b/drivers/usb/dwc3/dwc3-am62.c
@@ -97,7 +97,8 @@
#define USBSS_VBUS_STAT_SESSVALID BIT(2)
#define USBSS_VBUS_STAT_VBUSVALID BIT(0)

-/* Mask for PHY PLL REFCLK */
+/* USB_PHY_CTRL register bits in CTRL_MMR */
+#define PHY_CORE_VOLTAGE_MASK BIT(31)
#define PHY_PLL_REFCLK_MASK GENMASK(3, 0)

#define DWC3_AM62_AUTOSUSPEND_DELAY 100
@@ -162,6 +163,13 @@ static int phy_syscon_pll_refclk(struct dwc3_am62 *am62)

am62->offset = args.args[0];

+ /* Core voltage. PHY_CORE_VOLTAGE bit Recommended to be 0 always */
+ ret = regmap_update_bits(am62->syscon, am62->offset, PHY_CORE_VOLTAGE_MASK, 0);
+ if (ret) {
+ dev_err(dev, "failed to set phy core voltage\n");
+ return ret;
+ }
+
ret = regmap_update_bits(am62->syscon, am62->offset, PHY_PLL_REFCLK_MASK, am62->rate_code);
if (ret) {
dev_err(dev, "failed to set phy pll reference clock rate\n");
--
2.34.1