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usb: dwc2: bus suspend/resume for hosts with DWC2_POWER_DOWN_PARAM_NONE
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This is an attempt to rehash commit 0cf884e ("usb: dwc2: add bus
suspend/resume for dwc2") on ToT.  That commit was reverted in commit
b0bb9bb ("Revert "usb: dwc2: add bus suspend/resume for dwc2"")
because apparently it broke the Altera SOCFPGA.

With all the changes that have happened to dwc2 in the meantime, it's
possible that the Altera SOCFPGA will just magically work with this
change now.  ...and it would be good to get bus suspend/resume
implemented.

This change is a forward port of one that's been living in the Chrome
OS 3.14 kernel tree.

Signed-off-by: Douglas Anderson <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
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@dianders
dianders authored and Felipe Balbi committed May 3, 2019
1 parent c999933 commit 6f6d705
Showing 1 changed file with 53 additions and 31 deletions.
84 changes: 53 additions & 31 deletions drivers/usb/dwc2/hcd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4471,6 +4471,7 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
unsigned long flags;
int ret = 0;
u32 hprt0;
u32 pcgctl;

spin_lock_irqsave(&hsotg->lock, flags);

Expand All @@ -4486,7 +4487,7 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
if (hsotg->op_state == OTG_STATE_B_PERIPHERAL)
goto unlock;

if (hsotg->params.power_down != DWC2_POWER_DOWN_PARAM_PARTIAL)
if (hsotg->params.power_down > DWC2_POWER_DOWN_PARAM_PARTIAL)
goto skip_power_saving;

/*
Expand All @@ -4495,21 +4496,35 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
*/
if (!hsotg->bus_suspended) {
hprt0 = dwc2_read_hprt0(hsotg);
hprt0 |= HPRT0_SUSP;
hprt0 &= ~HPRT0_PWR;
dwc2_writel(hsotg, hprt0, HPRT0);
spin_unlock_irqrestore(&hsotg->lock, flags);
dwc2_vbus_supply_exit(hsotg);
spin_lock_irqsave(&hsotg->lock, flags);
if (hprt0 & HPRT0_CONNSTS) {
hprt0 |= HPRT0_SUSP;
if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL)
hprt0 &= ~HPRT0_PWR;
dwc2_writel(hsotg, hprt0, HPRT0);
}
if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
spin_unlock_irqrestore(&hsotg->lock, flags);
dwc2_vbus_supply_exit(hsotg);
spin_lock_irqsave(&hsotg->lock, flags);
} else {
pcgctl = readl(hsotg->regs + PCGCTL);
pcgctl |= PCGCTL_STOPPCLK;
writel(pcgctl, hsotg->regs + PCGCTL);
}
}

/* Enter partial_power_down */
ret = dwc2_enter_partial_power_down(hsotg);
if (ret) {
if (ret != -ENOTSUPP)
dev_err(hsotg->dev,
"enter partial_power_down failed\n");
goto skip_power_saving;
if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
/* Enter partial_power_down */
ret = dwc2_enter_partial_power_down(hsotg);
if (ret) {
if (ret != -ENOTSUPP)
dev_err(hsotg->dev,
"enter partial_power_down failed\n");
goto skip_power_saving;
}

/* After entering partial_power_down, hardware is no more accessible */
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
}

/* Ask phy to be suspended */
Expand All @@ -4519,9 +4534,6 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
spin_lock_irqsave(&hsotg->lock, flags);
}

/* After entering partial_power_down, hardware is no more accessible */
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

skip_power_saving:
hsotg->lx_state = DWC2_L2;
unlock:
Expand All @@ -4534,6 +4546,7 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
{
struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
unsigned long flags;
u32 pcgctl;
int ret = 0;

spin_lock_irqsave(&hsotg->lock, flags);
Expand All @@ -4544,17 +4557,11 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
if (hsotg->lx_state != DWC2_L2)
goto unlock;

if (hsotg->params.power_down != DWC2_POWER_DOWN_PARAM_PARTIAL) {
if (hsotg->params.power_down > DWC2_POWER_DOWN_PARAM_PARTIAL) {
hsotg->lx_state = DWC2_L0;
goto unlock;
}

/*
* Set HW accessible bit before powering on the controller
* since an interrupt may rise.
*/
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

/*
* Enable power if not already done.
* This must not be spinlocked since duration
Expand All @@ -4566,10 +4573,23 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
spin_lock_irqsave(&hsotg->lock, flags);
}

/* Exit partial_power_down */
ret = dwc2_exit_partial_power_down(hsotg, true);
if (ret && (ret != -ENOTSUPP))
dev_err(hsotg->dev, "exit partial_power_down failed\n");
if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
/*
* Set HW accessible bit before powering on the controller
* since an interrupt may rise.
*/
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);


/* Exit partial_power_down */
ret = dwc2_exit_partial_power_down(hsotg, true);
if (ret && (ret != -ENOTSUPP))
dev_err(hsotg->dev, "exit partial_power_down failed\n");
} else {
pcgctl = readl(hsotg->regs + PCGCTL);
pcgctl &= ~PCGCTL_STOPPCLK;
writel(pcgctl, hsotg->regs + PCGCTL);
}

hsotg->lx_state = DWC2_L0;

Expand All @@ -4581,10 +4601,12 @@ static int _dwc2_hcd_resume(struct usb_hcd *hcd)
spin_unlock_irqrestore(&hsotg->lock, flags);
dwc2_port_resume(hsotg);
} else {
dwc2_vbus_supply_init(hsotg);
if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_PARTIAL) {
dwc2_vbus_supply_init(hsotg);

/* Wait for controller to correctly update D+/D- level */
usleep_range(3000, 5000);
/* Wait for controller to correctly update D+/D- level */
usleep_range(3000, 5000);
}

/*
* Clear Port Enable and Port Status changes.
Expand Down

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