[PATCH 6/7] usb: dwc2: Add hibernation updates for ULPI PHY

[Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>]

Added programmming of ULPI_LATCH_EN_DURING_HIB_ENTRY bit in GPWRDN
register when using ULPI PHY during entry/exit to/from hibernation.
This bit set to 1 during entering to hibernation if ULPI PHY used.
On exiting from hibernation this bit reset to 0.
Applicable for both host and device modes.

Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>
---
 drivers/usb/dwc2/core.c      |  5 +++++
 drivers/usb/dwc2/core_intr.c |  5 +++++
 drivers/usb/dwc2/gadget.c    | 23 +++++++++++++++++++++++
 drivers/usb/dwc2/hcd.c       | 10 ++++++++++
 4 files changed, 43 insertions(+)

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 5635e4d7ec88..b7a76eb089c9 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -249,6 +249,11 @@ void dwc2_hib_restore_common(struct dwc2_hsotg *hsotg, int rem_wakeup,
 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
 	udelay(10);
 
+	/* Reset ULPI latch */
+	gpwrdn = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+	dwc2_writel(hsotg, gpwrdn, GPWRDN);
+
 	/* Disable PMU interrupt */
 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
 	gpwrdn &= ~GPWRDN_PMUINTSEL;
diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index bb6bb771375a..aee779898c06 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -705,6 +705,11 @@ static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
 	gpwrdn_tmp &= ~GPWRDN_PMUINTSEL;
 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
 
+	/* Reset ULPI latch */
+	gpwrdn = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+	dwc2_writel(hsotg, gpwrdn, GPWRDN);
+
 	/* De-assert Wakeup Logic */
 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
 	gpwrdn_tmp &= ~GPWRDN_PMUACTV;
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 680737d471c1..f67e69999e3e 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -5309,6 +5309,8 @@ void dwc2_gadget_program_ref_clk(struct dwc2_hsotg *hsotg)
 int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
 {
 	u32 gpwrdn;
+	u32 gusbcfg;
+	u32 pcgcctl;
 	int ret = 0;
 
 	/* Change to L2(suspend) state */
@@ -5328,6 +5330,22 @@ int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
 	}
 
 	gpwrdn = GPWRDN_PWRDNRSTN;
+	udelay(10);
+	gusbcfg = dwc2_readl(hsotg, GUSBCFG);
+	if (gusbcfg & GUSBCFG_ULPI_UTMI_SEL) {
+		/* ULPI interface */
+		gpwrdn |= GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+	}
+	dwc2_writel(hsotg, gpwrdn, GPWRDN);
+	udelay(10);
+
+	/* Suspend the Phy Clock */
+	pcgcctl = dwc2_readl(hsotg, PCGCTL);
+	pcgcctl |= PCGCTL_STOPPCLK;
+	dwc2_writel(hsotg, pcgcctl, PCGCTL);
+	udelay(10);
+
+	gpwrdn = dwc2_readl(hsotg, GPWRDN);
 	gpwrdn |= GPWRDN_PMUACTV;
 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
 	udelay(10);
@@ -5428,6 +5446,11 @@ int dwc2_gadget_exit_hibernation(struct dwc2_hsotg *hsotg,
 	if (reset)
 		dwc2_clear_bit(hsotg, DCFG, DCFG_DEVADDR_MASK);
 
+	/* Reset ULPI latch */
+	gpwrdn = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+	dwc2_writel(hsotg, gpwrdn, GPWRDN);
+
 	/* De-assert Wakeup Logic */
 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
 	gpwrdn &= ~GPWRDN_PMUACTV;
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 35c7a4df8e71..cc75a7062910 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5503,6 +5503,11 @@ int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg)
 	gusbcfg = dwc2_readl(hsotg, GUSBCFG);
 	if (gusbcfg & GUSBCFG_ULPI_UTMI_SEL) {
 		/* ULPI interface */
+		udelay(10);
+		gpwrdn = dwc2_readl(hsotg, GPWRDN);
+		gpwrdn |= GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+		dwc2_writel(hsotg, gpwrdn, GPWRDN);
+		udelay(10);
 		/* Suspend the Phy Clock */
 		pcgcctl = dwc2_readl(hsotg, PCGCTL);
 		pcgcctl |= PCGCTL_STOPPCLK;
@@ -5609,6 +5614,11 @@ int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup,
 	dwc2_writel(hsotg, gr->gusbcfg, GUSBCFG);
 	dwc2_writel(hsotg, hr->hcfg, HCFG);
 
+	/* Reset ULPI latch */
+	gpwrdn = dwc2_readl(hsotg, GPWRDN);
+	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
+	dwc2_writel(hsotg, gpwrdn, GPWRDN);
+
 	/* De-assert Wakeup Logic */
 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
 	gpwrdn &= ~GPWRDN_PMUACTV;
-- 
2.41.0