On 05/02/2024 20:07, Andrew Davis wrote: > On 2/5/24 8:12 AM, Roger Quadros wrote: >> 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; >> + } > > Why not move this down to where you use it below, then just have > it be an if/else with the work around in the if (!IS_ERR(phy)) > and the warning in the else. Seems reasonable. Will fix. > > Andrew > >> + >> 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); -- cheers, -roger
