dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

usb: dwc2: Implement recovery after PM domain off

Browse Source 
According to the dt-bindings there are some platforms, which have a
dedicated USB power domain for DWC2 IP core supply. If the power domain
is switched off during system suspend then all USB register will lose
their settings.

Use GUSBCFG_TOUTCAL as a canary to detect that the power domain has
been powered off during suspend. Since the GOTGCTL_CURMODE_HOST doesn't
match on all platform with the current mode, additionally backup
GINTSTS. This works reliable to decide which registers should be
restored.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250217134132.36786-4-wahrenst@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stefan Wahren
2025-02-19 15:15:54 +01:00
committed by Greg Kroah-Hartman
parent 8b7a1b3da2
commit ba6e518d13
3 changed files with 41 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/usb/dwc2/core.c
+1
View File
@@ -43,6 +43,7 @@ int dwc2_backup_global_registers(struct dwc2_hsotg *hsotg)
/* Backup global regs */
gr = &hsotg->gr_backup;
gr->gintsts = dwc2_readl(hsotg, GINTSTS);
gr->gotgctl = dwc2_readl(hsotg, GOTGCTL);
gr->gintmsk = dwc2_readl(hsotg, GINTMSK);
gr->gahbcfg = dwc2_readl(hsotg, GAHBCFG);
drivers/usb/dwc2/core.h
+2
View File
@@ -667,6 +667,7 @@ struct dwc2_hw_params {
/**
* struct dwc2_gregs_backup - Holds global registers state before
* entering partial power down
* @gintsts: Backup of GINTSTS register
* @gotgctl: Backup of GOTGCTL register
* @gintmsk: Backup of GINTMSK register
* @gahbcfg: Backup of GAHBCFG register
@@ -683,6 +684,7 @@ struct dwc2_hw_params {
* @valid: True if registers values backuped.
*/
struct dwc2_gregs_backup {
u32 gintsts;
u32 gotgctl;
u32 gintmsk;
u32 gahbcfg;
drivers/usb/dwc2/platform.c
+38
View File
@@ -685,6 +685,14 @@ static int __maybe_unused dwc2_suspend(struct device *dev)
regulator_disable(dwc2->usb33d);
}
if (is_device_mode)
ret = dwc2_gadget_backup_critical_registers(dwc2);
else
ret = dwc2_host_backup_critical_registers(dwc2);
if (ret)
return ret;
if (dwc2->ll_hw_enabled &&
(is_device_mode || dwc2_host_can_poweroff_phy(dwc2))) {
ret = __dwc2_lowlevel_hw_disable(dwc2);
@@ -694,6 +702,24 @@ static int __maybe_unused dwc2_suspend(struct device *dev)
return ret;
}
static int dwc2_restore_critical_registers(struct dwc2_hsotg *hsotg)
{
struct dwc2_gregs_backup *gr;
gr = &hsotg->gr_backup;
if (!gr->valid) {
dev_err(hsotg->dev, "No valid register backup, failed to restore\n");
return -EINVAL;
}
if (gr->gintsts & GINTSTS_CURMODE_HOST)
return dwc2_host_restore_critical_registers(hsotg);
return dwc2_gadget_restore_critical_registers(hsotg, DWC2_RESTORE_DCTL |
DWC2_RESTORE_DCFG);
}
static int __maybe_unused dwc2_resume(struct device *dev)
{
struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
@@ -706,6 +732,18 @@ static int __maybe_unused dwc2_resume(struct device *dev)
}
dwc2->phy_off_for_suspend = false;
/*
* During suspend it's possible that the power domain for the
* DWC2 controller is disabled and all register values get lost.
* In case the GUSBCFG register is not initialized, it's clear the
* registers must be restored.
*/
if (!(dwc2_readl(dwc2, GUSBCFG) & GUSBCFG_TOUTCAL_MASK)) {
ret = dwc2_restore_critical_registers(dwc2);
if (ret)
return ret;
}
if (dwc2->params.activate_stm_id_vb_detection) {
unsigned long flags;
u32 ggpio, gotgctl;