[PATCH 1/1] usb: dwc2: fix STM ID/VBUS detection startup delay in dwc2_driver_probe

From: Amelie Delaunay <amelie.delaunay@foss.st.com>
To: Minas Harutyunyan <hminas@synopsys.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	Fabrice Gasnier <fabrice.gasnier@foss.st.com>,
	Amelie Delaunay <amelie.delaunay@foss.st.com>
Subject: [PATCH 1/1] usb: dwc2: fix STM ID/VBUS detection startup delay in dwc2_driver_probe
Date: Tue, 7 Dec 2021 13:45:10 +0100	[thread overview]
Message-ID: <20211207124510.268841-1-amelie.delaunay@foss.st.com> (raw)

When activate_stm_id_vb_detection is enabled, ID and Vbus detection relies
on sensing comparators. This detection needs time to stabilize.
A delay was already applied in dwc2_resume() when reactivating the
detection, but it wasn't done in dwc2_probe().
This patch adds delay after enabling STM ID/VBUS detection. Then, ID state
is good when initializing gadget and host, and avoid to get a wrong
Connector ID Status Change interrupt.

Fixes: a415083a11cc ("usb: dwc2: add support for STM32MP15 SoCs USB OTG HS and FS")
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
 drivers/usb/dwc2/platform.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index a1feaa09be57..55d7fca6f95c 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -555,6 +555,9 @@ static int dwc2_driver_probe(struct platform_device *dev)
 		ggpio |= GGPIO_STM32_OTG_GCCFG_IDEN;
 		ggpio |= GGPIO_STM32_OTG_GCCFG_VBDEN;
 		dwc2_writel(hsotg, ggpio, GGPIO);
+
+		/* ID/VBUS detection startup time */
+		usleep_range(5000, 7000);
 	}
 
 	retval = dwc2_drd_init(hsotg);
-- 
2.25.1

