usb: dwc3: gadget: clear SUSPHY bit before ep cmds
Upstream Linux commit 2b0f11df84bb.
Synopsys Databook 2.60a has a note that if we're
sending an endpoint command we _must_ make sure that
DWC3_GUSB2PHY(n).SUSPHY bit is cleared.
This patch implements that particular detail.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20240412202611.3565052-3-alexander.sverdlin@siemens.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index b4cc238..06a29ed 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -301,8 +301,25 @@
{
u32 timeout = 500;
u32 reg;
+
+ int susphy = false;
int ret = -EINVAL;
+ /*
+ * Synopsys Databook 2.60a states, on section 6.3.2.5.[1-8], that if
+ * we're issuing an endpoint command, we must check if
+ * GUSB2PHYCFG.SUSPHY bit is set. If it is, then we need to clear it.
+ *
+ * We will also set SUSPHY bit to what it was before returning as stated
+ * by the same section on Synopsys databook.
+ */
+ reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+ if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
+ susphy = true;
+ reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+ dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+ }
+
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);
@@ -330,6 +347,12 @@
udelay(1);
} while (1);
+ if (unlikely(susphy)) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+ reg |= DWC3_GUSB2PHYCFG_SUSPHY;
+ dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+ }
+
return ret;
}