[PATCH v3 3/3] phy: omap-usb2-phy: disable PHY charger detect

Roger Quadros
2020-06-30T09:27:49Z

AM654x PG1.0 has a silicon bug that D+ is pulled high after POR, which
could cause enumeration failure with some USB hubs. Disabling the
USB2_PHY Charger Detect function will put D+ into the normal state.

Using property "ti,disable-charger-det" in the DT usb2-phy node to
enable this workaround for AM654x PG1.0.

This addresses Silicon Errata:
i2075 - "USB2PHY: USB2PHY Charger Detect is Enabled by Default Without VBUS
Presence"

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
---
drivers/phy/ti/phy-omap-usb2.c | 35 +++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
index cb2dd3230fa7..21c3904d4efc 100644
--- a/drivers/phy/ti/phy-omap-usb2.c
+++ b/drivers/phy/ti/phy-omap-usb2.c
@@ -26,6 +26,10 @@
#define USB2PHY_ANA_CONFIG1 0x4c
#define USB2PHY_DISCON_BYP_LATCH BIT(31)

+#define USB2PHY_CHRG_DET 0x14
+#define USB2PHY_CHRG_DET_USE_CHG_DET_REG BIT(29)
+#define USB2PHY_CHRG_DET_DIS_CHG_DET BIT(28)
+
/* SoC Specific USB2_OTG register definitions */
#define AM654_USB2_OTG_PD BIT(8)
#define AM654_USB2_VBUS_DET_EN BIT(5)
@@ -43,6 +47,7 @@
#define OMAP_USB2_HAS_START_SRP BIT(0)
#define OMAP_USB2_HAS_SET_VBUS BIT(1)
#define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT BIT(2)
+#define OMAP_USB2_DISABLE_CHRG_DET BIT(3)

struct omap_usb {
struct usb_phy phy;
@@ -236,6 +241,13 @@ static int omap_usb_init(struct phy *x)
omap_usb_writel(phy->phy_base, USB2PHY_ANA_CONFIG1, val);
}

+ if (phy->flags & OMAP_USB2_DISABLE_CHRG_DET) {
+ val = omap_usb_readl(phy->phy_base, USB2PHY_CHRG_DET);
+ val |= USB2PHY_CHRG_DET_USE_CHG_DET_REG |
+ USB2PHY_CHRG_DET_DIS_CHG_DET;
+ omap_usb_writel(phy->phy_base, USB2PHY_CHRG_DET, val);
+ }
+
return 0;
}

@@ -366,14 +378,12 @@ static int omap_usb2_probe(struct platform_device *pdev)
phy->mask = phy_data->mask;
phy->power_on = phy_data->power_on;
phy->power_off = phy_data->power_off;
+ phy->flags = phy_data->flags;

- if (phy_data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(phy->phy_base))
- return PTR_ERR(phy->phy_base);
- phy->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
- }
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(phy->phy_base))
+ return PTR_ERR(phy->phy_base);

phy->syscon_phy_power = syscon_regmap_lookup_by_phandle(node,
"syscon-phy-power");
@@ -405,6 +415,17 @@ static int omap_usb2_probe(struct platform_device *pdev)
}
}

+ /*
+ * Errata i2075: USB2PHY: USB2PHY Charger Detect is Enabled by
+ * Default Without VBUS Presence.
+ *
+ * AM654x SR1.0 has a silicon bug due to which D+ is pulled high after
+ * POR, which could cause enumeration failure with some USB hubs.
+ * Disabling the USB2_PHY Charger Detect function will put D+
+ * into the normal state.
+ */
+ if (of_property_read_bool(node, "ti,disable-charger-det"))
+ phy->flags |= OMAP_USB2_DISABLE_CHRG_DET;

phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
if (IS_ERR(phy->wkupclk)) {