usb: dwc2: Add host/device hibernation functions

Add host/device hibernation functions which must be wrapped
by core's  dwc2_enter_hibernation()/dwc2_exit_hibernation()
functions.

Make dwc2_backup_global_registers dwc2_restore_global_register
non-static to use them in both host/gadget sides.

Added function names:
dwc2_gadget_enter_hibernation()
dwc2_gadget_exit_hibernation()
dwc2_host_enter_hibernation()
dwc2_host_exit_hibernation()

Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Artur Petrosyan <arturp@synopsys.com>
Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 176 insertions, 0 deletions

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 838e0929db59..6c32bf26e48e 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -4913,3 +4913,179 @@ void dwc2_gadget_init_lpm(struct dwc2_hsotg *hsotg)
 	dev_dbg(hsotg->dev, "GLPMCFG=0x%08x\n", dwc2_readl(hsotg->regs
 		+ GLPMCFG));
 }
+
+/**
+ * dwc2_gadget_enter_hibernation() - Put controller in Hibernation.
+ *
+ * @hsotg: Programming view of the DWC_otg controller
+ *
+ * Return non-zero if failed to enter to hibernation.
+ */
+int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
+{
+	u32 gpwrdn;
+	int ret = 0;
+
+	/* Change to L2(suspend) state */
+	hsotg->lx_state = DWC2_L2;
+	dev_dbg(hsotg->dev, "Start of hibernation completed\n");
+	ret = dwc2_backup_global_registers(hsotg);
+	if (ret) {
+		dev_err(hsotg->dev, "%s: failed to backup global registers\n",
+			__func__);
+		return ret;
+	}
+	ret = dwc2_backup_device_registers(hsotg);
+	if (ret) {
+		dev_err(hsotg->dev, "%s: failed to backup device registers\n",
+			__func__);
+		return ret;
+	}
+
+	gpwrdn = GPWRDN_PWRDNRSTN;
+	gpwrdn |= GPWRDN_PMUACTV;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	/* Set flag to indicate that we are in hibernation */
+	hsotg->hibernated = 1;
+
+	/* Enable interrupts from wake up logic */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn |= GPWRDN_PMUINTSEL;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	/* Unmask device mode interrupts in GPWRDN */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn |= GPWRDN_RST_DET_MSK;
+	gpwrdn |= GPWRDN_LNSTSCHG_MSK;
+	gpwrdn |= GPWRDN_STS_CHGINT_MSK;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	/* Enable Power Down Clamp */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn |= GPWRDN_PWRDNCLMP;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	/* Switch off VDD */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn |= GPWRDN_PWRDNSWTCH;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	/* Save gpwrdn register for further usage if stschng interrupt */
+	hsotg->gr_backup.gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	dev_dbg(hsotg->dev, "Hibernation completed\n");
+
+	return ret;
+}
+
+/**
+ * dwc2_gadget_exit_hibernation()
+ * This function is for exiting from Device mode hibernation by host initiated
+ * resume/reset and device initiated remote-wakeup.
+ *
+ * @hsotg: Programming view of the DWC_otg controller
+ * @rem_wakeup: indicates whether resume is initiated by Device or Host.
+ * @param reset: indicates whether resume is initiated by Reset.
+ *
+ * Return non-zero if failed to exit from hibernation.
+ */
+int dwc2_gadget_exit_hibernation(struct dwc2_hsotg *hsotg,
+				 int rem_wakeup, int reset)
+{
+	u32 pcgcctl;
+	u32 gpwrdn;
+	u32 dctl;
+	int ret = 0;
+	struct dwc2_gregs_backup *gr;
+	struct dwc2_dregs_backup *dr;
+
+	gr = &hsotg->gr_backup;
+	dr = &hsotg->dr_backup;
+
+	if (!hsotg->hibernated) {
+		dev_dbg(hsotg->dev, "Already exited from Hibernation\n");
+		return 1;
+	}
+	dev_dbg(hsotg->dev,
+		"%s: called with rem_wakeup = %d reset = %d\n",
+		__func__, rem_wakeup, reset);
+
+	dwc2_hib_restore_common(hsotg, rem_wakeup, 0);
+
+	if (!reset) {
+		/* Clear all pending interupts */
+		dwc2_writel(0xffffffff, hsotg->regs + GINTSTS);
+	}
+
+	/* De-assert Restore */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn &= ~GPWRDN_RESTORE;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+	udelay(10);
+
+	if (!rem_wakeup) {
+		pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
+		pcgcctl &= ~PCGCTL_RSTPDWNMODULE;
+		dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
+	}
+
+	/* Restore GUSBCFG, DCFG and DCTL */
+	dwc2_writel(gr->gusbcfg, hsotg->regs + GUSBCFG);
+	dwc2_writel(dr->dcfg, hsotg->regs + DCFG);
+	dwc2_writel(dr->dctl, hsotg->regs + DCTL);
+
+	/* De-assert Wakeup Logic */
+	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
+	gpwrdn &= ~GPWRDN_PMUACTV;
+	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
+
+	if (rem_wakeup) {
+		udelay(10);
+		/* Start Remote Wakeup Signaling */
+		dwc2_writel(dr->dctl | DCTL_RMTWKUPSIG, hsotg->regs + DCTL);
+	} else {
+		udelay(50);
+		/* Set Device programming done bit */
+		dctl = dwc2_readl(hsotg->regs + DCTL);
+		dctl |= DCTL_PWRONPRGDONE;
+		dwc2_writel(dctl, hsotg->regs + DCTL);
+	}
+	/* Wait for interrupts which must be cleared */
+	mdelay(2);
+	/* Clear all pending interupts */
+	dwc2_writel(0xffffffff, hsotg->regs + GINTSTS);
+
+	/* Restore global registers */
+	ret = dwc2_restore_global_registers(hsotg);
+	if (ret) {
+		dev_err(hsotg->dev, "%s: failed to restore registers\n",
+			__func__);
+		return ret;
+	}
+
+	/* Restore device registers */
+	ret = dwc2_restore_device_registers(hsotg, rem_wakeup);
+	if (ret) {
+		dev_err(hsotg->dev, "%s: failed to restore device registers\n",
+			__func__);
+		return ret;
+	}
+
+	if (rem_wakeup) {
+		mdelay(10);
+		dctl = dwc2_readl(hsotg->regs + DCTL);
+		dctl &= ~DCTL_RMTWKUPSIG;
+		dwc2_writel(dctl, hsotg->regs + DCTL);
+	}
+
+	hsotg->hibernated = 0;
+	hsotg->lx_state = DWC2_L0;
+	dev_dbg(hsotg->dev, "Hibernation recovery completes here\n");
+
+	return ret;
+}