[PATCH v4 6/9] usb: dwc3: save/restore OTG registers during suspend/resume

Roger Quadros
2015-09-02T14:24:53Z

Without this we loose OTG controller register context and malfunction
after a system suspend-resume.

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
drivers/usb/dwc3/core.c | 17 +++++++++++++++++
drivers/usb/dwc3/core.h | 6 +++++-
2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 632ee53..684010c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -56,6 +56,7 @@ void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
reg |= DWC3_GCTL_PRTCAPDIR(mode);
+ dwc->current_mode = mode;
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
}

@@ -1443,6 +1444,14 @@ static int dwc3_suspend(struct device *dev)

spin_lock_irqsave(&dwc->lock, flags);

+ /* Save OTG state only if we're really using it */
+ if (dwc->current_mode == DWC3_GCTL_PRTCAP_OTG) {
+ dwc->ocfg = dwc3_readl(dwc->regs, DWC3_OCFG);
+ dwc->octl = dwc3_readl(dwc->regs, DWC3_OCTL);
+ dwc->oevt = dwc3_readl(dwc->regs, DWC3_OEVT);
+ dwc->oevten = dwc3_readl(dwc->regs, DWC3_OEVTEN);
+ }
+
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
@@ -1486,6 +1495,14 @@ static int dwc3_resume(struct device *dev)
dwc3_event_buffers_setup(dwc);
dwc3_writel(dwc->regs, DWC3_GCTL, dwc->gctl);

+ /* Restore OTG state only if we're really using it */
+ if (dwc->current_mode == DWC3_GCTL_PRTCAP_OTG) {
+ dwc3_writel(dwc->regs, DWC3_OCFG, dwc->ocfg);
+ dwc3_writel(dwc->regs, DWC3_OCTL, dwc->octl);
+ dwc3_writel(dwc->regs, DWC3_OEVT, dwc->oevt);
+ dwc3_writel(dwc->regs, DWC3_OEVTEN, dwc->oevten);
+ }
+
switch (dwc->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
case USB_DR_MODE_OTG:
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 129ef37..1115ce0 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -737,6 +737,7 @@ struct dwc3_scratchpad_array {
* @regs: base address for our registers
* @regs_size: address space size
* @oevten: otg interrupt enable mask copy
+ * @current_mode: current mode of operation written to PRTCAPDIR
* @nr_scratch: number of scratch buffers
* @num_event_buffers: calculated number of event buffers
* @u1u2: only used on revisions <1.83a for workaround
@@ -858,9 +859,12 @@ struct dwc3 {
/* used for suspend/resume */
u32 dcfg;
u32 gctl;
-
+ u32 ocfg;
+ u32 octl;
+ u32 oevt;
u32 oevten;

+ u32 current_mode;
u32 nr_scratch;
u32 num_event_buffers;
u32 u1u2;
--
2.1.4