Commit f0b9c578 authored by Roger Quadros's avatar Roger Quadros Committed by Greg Kroah-Hartman
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usb: dwc3-am62: add workaround for Errata i2409 

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



Signed-off-by: default avatarRoger Quadros <rogerq@kernel.org>
Acked-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20240227-for-v6-9-am62-usb-errata-3-0-v4-4-0ada8ddb0767@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d78ff375

drivers/usb/dwc3/dwc3-am62.c

+18 −1
Original line number Diff line number Diff line
@@ -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);
@@ -227,6 +233,17 @@ static int dwc3_ti_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	/* Workaround Errata i2409 */

	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;

	} else {

		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);