From bbb3f0a52148d80e78bea4be6b974ed396ad6b57 Mon Sep 17 00:00:00 2001
From: Matthias Maennich <maennich@google.com>
Date: Mon, 11 Nov 2024 09:40:20 +0000
Subject: [PATCH] Reapply "usb: dwc3: core: Fix system suspend on TI AM62
 platforms"

This reverts commit e4f5dbb4c4891d3569fe197549b5e4ed6f10acdf.

With 9cfb31e4c89d ("usb: dwc3: fix fault at system suspend if device was
already runtime suspended") applied (that comes with 6.12-rc7), the
original commit can be reinstated.

Bug: 377320141
Cc: Will McVicker <willmcvicker@google.com>
Change-Id: Icd1798c9c473ac5ac5fd00b6198e07e8e6f02313
Signed-off-by: Matthias Maennich <maennich@google.com>
---
 drivers/usb/dwc3/core.c | 19 +++++++++++++++++++
 drivers/usb/dwc3/core.h |  3 +++
 2 files changed, 22 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 21740e2b8f07..427e5660f87c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -2342,6 +2342,11 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 	u32 reg;
 	int i;
 
+	dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
+			    DWC3_GUSB2PHYCFG_SUSPHY) ||
+			    (dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0)) &
+			    DWC3_GUSB3PIPECTL_SUSPHY);
+
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (pm_runtime_suspended(dwc->dev))
@@ -2393,6 +2398,15 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 		break;
 	}
 
+	if (!PMSG_IS_AUTO(msg)) {
+		/*
+		 * TI AM62 platform requires SUSPHY to be
+		 * enabled for system suspend to work.
+		 */
+		if (!dwc->susphy_state)
+			dwc3_enable_susphy(dwc, true);
+	}
+
 	return 0;
 }
 
@@ -2460,6 +2474,11 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 		break;
 	}
 
+	if (!PMSG_IS_AUTO(msg)) {
+		/* restore SUSPHY state to that before system suspend. */
+		dwc3_enable_susphy(dwc, dwc->susphy_state);
+	}
+
 	return 0;
 }
 
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 9c508e0c5cdf..eab81dfdcc35 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1150,6 +1150,8 @@ struct dwc3_scratchpad_array {
  * @sys_wakeup: set if the device may do system wakeup.
  * @wakeup_configured: set if the device is configured for remote wakeup.
  * @suspended: set to track suspend event due to U3/L2.
+ * @susphy_state: state of DWC3_GUSB2PHYCFG_SUSPHY + DWC3_GUSB3PIPECTL_SUSPHY
+ *		  before PM suspend.
  * @imod_interval: set the interrupt moderation interval in 250ns
  *			increments or 0 to disable.
  * @max_cfg_eps: current max number of IN eps used across all USB configs.
@@ -1382,6 +1384,7 @@ struct dwc3 {
 	unsigned		sys_wakeup:1;
 	unsigned		wakeup_configured:1;
 	unsigned		suspended:1;
+	unsigned		susphy_state:1;
 
 	u16			imod_interval;