All AM62 devices have Errata i2409 [1] due to which USB2 PHY may lock up due to short suspend. Workaround involves setting bit 5 and 4 PLL_REG12 in PHY2 register space after USB controller is brought out of LPSC reset but before controller initialization. Handle this workaround. [1] - https://www.ti.com/lit/er/sprz487d/sprz487d.pdf Cc: Rob Herring <robh+dt@xxxxxxxxxx> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx> Cc: Conor Dooley <conor+dt@xxxxxxxxxx> Signed-off-by: Roger Quadros <rogerq@xxxxxxxxxx> --- Notes: Changelog: v2: - don't add phy read/write helpers or add phy to private data v1: https://lore.kernel.org/all/20240201121220.5523-5-rogerq@xxxxxxxxxx/ drivers/usb/dwc3/dwc3-am62.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c index af1ce934e7fb..5ae5c3087b0f 100644 --- a/drivers/usb/dwc3/dwc3-am62.c +++ b/drivers/usb/dwc3/dwc3-am62.c @@ -101,6 +101,11 @@ #define PHY_CORE_VOLTAGE_MASK BIT(31) #define PHY_PLL_REFCLK_MASK GENMASK(3, 0) +/* USB PHY2 register offsets */ +#define USB_PHY_PLL_REG12 0x130 +#define USB_PHY_PLL_LDO_REF_EN BIT(5) +#define USB_PHY_PLL_LDO_REF_EN_EN BIT(4) + #define DWC3_AM62_AUTOSUSPEND_DELAY 100 struct dwc3_am62 { @@ -184,8 +189,9 @@ static int dwc3_ti_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *node = pdev->dev.of_node; struct dwc3_am62 *am62; - int i, ret; unsigned long rate; + void __iomem *phy; + int i, ret; u32 reg; am62 = devm_kzalloc(dev, sizeof(*am62), GFP_KERNEL); @@ -201,6 +207,12 @@ static int dwc3_ti_probe(struct platform_device *pdev) return PTR_ERR(am62->usbss); } + phy = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(phy)) { + dev_err(dev, "can't map PHY IOMEM resource. Won't apply i2409 fix.\n"); + phy = NULL; + } + am62->usb2_refclk = devm_clk_get(dev, "ref"); if (IS_ERR(am62->usb2_refclk)) { dev_err(dev, "can't get usb2_refclk\n"); @@ -227,6 +239,13 @@ static int dwc3_ti_probe(struct platform_device *pdev) if (ret) return ret; + /* Workaround Errata i2409 */ + if (phy) { + reg = readl(phy + USB_PHY_PLL_REG12); + reg |= USB_PHY_PLL_LDO_REF_EN | USB_PHY_PLL_LDO_REF_EN_EN; + writel(reg, phy + USB_PHY_PLL_REG12); + } + /* VBUS divider select */ am62->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider"); reg = dwc3_ti_readl(am62, USBSS_PHY_CONFIG); -- 2.34.1
