usb: dwc3: ep0: add LPM handling

On device loading the driver enables LPM and the acceptance of U1 and U2
states. The [Set|Clear]Feature requests for "U1/U2" are forwarded
directly to the hardware and allow / forbid the initiation of the low
power links.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

3 files changed, 45 insertions, 11 deletions

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index c7b3ca037bbc..93f9973ad53e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -194,6 +194,7 @@
 #define DWC3_GHWPARAMS1_EN_PWROPT_CLK   1
 
 /* Device Configuration Register */
+#define DWC3_DCFG_LPM_CAP       (1 << 22)
 #define DWC3_DCFG_DEVADDR(addr) ((addr) << 3)
 #define DWC3_DCFG_DEVADDR_MASK  DWC3_DCFG_DEVADDR(0x7f)
 
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 25910e251c04..18494b0d7d6e 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -261,6 +261,7 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
 {
         struct dwc3_ep          *dep;
         u32                     recip;
+        u32                     reg;
         u16                     usb_status = 0;
         __le16                  *response_pkt;
 
@@ -268,10 +269,18 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
         switch (recip) {
         case USB_RECIP_DEVICE:
                 /*
-                 * We are self-powered. U1/U2/LTM will be set later
-                 * once we handle this states. RemoteWakeup is 0 on SS
+                 * LTM will be set once we know how to set this in HW.
                  */
                 usb_status |= dwc->is_selfpowered << USB_DEVICE_SELF_POWERED;
+
+                if (dwc->speed == DWC3_DSTS_SUPERSPEED) {
+                        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+                        if (reg & DWC3_DCTL_INITU1ENA)
+                                usb_status |= 1 << USB_DEV_STAT_U1_ENABLED;
+                        if (reg & DWC3_DCTL_INITU2ENA)
+                                usb_status |= 1 << USB_DEV_STAT_U2_ENABLED;
+                }
+
                 break;
 
         case USB_RECIP_INTERFACE:
@@ -312,6 +321,7 @@ static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
         u32                     recip;
         u32                     wValue;
         u32                     wIndex;
+        u32                     reg;
         int                     ret;
 
         wValue = le16_to_cpu(ctrl->wValue);
@@ -320,29 +330,43 @@ static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
         switch (recip) {
         case USB_RECIP_DEVICE:
 
+                switch (wValue) {
+                case USB_DEVICE_REMOTE_WAKEUP:
+                        break;
                 /*
                  * 9.4.1 says only only for SS, in AddressState only for
                  * default control pipe
                  */
-                switch (wValue) {
                 case USB_DEVICE_U1_ENABLE:
-                case USB_DEVICE_U2_ENABLE:
-                case USB_DEVICE_LTM_ENABLE:
                         if (dwc->dev_state != DWC3_CONFIGURED_STATE)
                                 return -EINVAL;
                         if (dwc->speed != DWC3_DSTS_SUPERSPEED)
                                 return -EINVAL;
-                }
 
-                /* XXX add U[12] & LTM */
-                switch (wValue) {
-                case USB_DEVICE_REMOTE_WAKEUP:
-                        break;
-                case USB_DEVICE_U1_ENABLE:
+                        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+                        if (set)
+                                reg |= DWC3_DCTL_INITU1ENA;
+                        else
+                                reg &= ~DWC3_DCTL_INITU1ENA;
+                        dwc3_writel(dwc->regs, DWC3_DCTL, reg);
                         break;
+
                 case USB_DEVICE_U2_ENABLE:
+                        if (dwc->dev_state != DWC3_CONFIGURED_STATE)
+                                return -EINVAL;
+                        if (dwc->speed != DWC3_DSTS_SUPERSPEED)
+                                return -EINVAL;
+
+                        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+                        if (set)
+                                reg |= DWC3_DCTL_INITU2ENA;
+                        else
+                                reg &= ~DWC3_DCTL_INITU2ENA;
+                        dwc3_writel(dwc->regs, DWC3_DCTL, reg);
                         break;
+
                 case USB_DEVICE_LTM_ENABLE:
+                        return -EINVAL;
                         break;
 
                 case USB_DEVICE_TEST_MODE:
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index dda56b8f8617..906db570ef4f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1933,6 +1933,7 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 
         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
         reg &= ~DWC3_DCTL_TSTCTRL_MASK;
+        reg &= ~(DWC3_DCTL_INITU1ENA | DWC3_DCTL_INITU2ENA);
         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
         dwc->test_mode = false;
 
@@ -2330,6 +2331,14 @@ int __devinit dwc3_gadget_init(struct dwc3 *dwc)
                 goto err5;
         }
 
+        reg = dwc3_readl(dwc->regs, DWC3_DCFG);
+        reg |= DWC3_DCFG_LPM_CAP;
+        dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
+        reg |= DWC3_DCTL_ACCEPTU1ENA | DWC3_DCTL_ACCEPTU2ENA;
+        dwc3_writel(dwc->regs, DWC3_DCTL, reg);
+
         /* Enable all but Start and End of Frame IRQs */
         reg = (DWC3_DEVTEN_VNDRDEVTSTRCVEDEN |
                         DWC3_DEVTEN_EVNTOVERFLOWEN |