usb: dwc2: Refactor backup/restore of registers

The DWC2 runtime PM code reuses similar patterns to backup and
restore the registers. So consolidate them in USB mode specific
variants. This also has the advantage it is reusable for further
PM improvements.

Special care is taken for DCFG register during device mode restore.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20250217134132.36786-3-wahrenst@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 48f4b639ca2fabe75e51b8c62b75044c967e7935..265791fbe87f643bfa546ea80227f0f5f82e26b0 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -1128,6 +1128,7 @@ struct dwc2_hsotg {
 #define DWC2_HS_IOT_ID         0x55320000
 
 #define DWC2_RESTORE_DCTL BIT(0)
+#define DWC2_RESTORE_DCFG BIT(1)
 
 #if IS_ENABLED(CONFIG_USB_DWC2_HOST) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
        union dwc2_hcd_internal_flags {
@@ -1437,6 +1438,9 @@ int dwc2_hsotg_tx_fifo_total_depth(struct dwc2_hsotg *hsotg);
 int dwc2_hsotg_tx_fifo_average_depth(struct dwc2_hsotg *hsotg);
 void dwc2_gadget_init_lpm(struct dwc2_hsotg *hsotg);
 void dwc2_gadget_program_ref_clk(struct dwc2_hsotg *hsotg);
+int dwc2_gadget_backup_critical_registers(struct dwc2_hsotg *hsotg);
+int dwc2_gadget_restore_critical_registers(struct dwc2_hsotg *hsotg,
+                                          unsigned int flags);
 static inline void dwc2_clear_fifo_map(struct dwc2_hsotg *hsotg)
 { hsotg->fifo_map = 0; }
 #else
@@ -1484,6 +1488,11 @@ static inline int dwc2_hsotg_tx_fifo_average_depth(struct dwc2_hsotg *hsotg)
 { return 0; }
 static inline void dwc2_gadget_init_lpm(struct dwc2_hsotg *hsotg) {}
 static inline void dwc2_gadget_program_ref_clk(struct dwc2_hsotg *hsotg) {}
+static inline int dwc2_gadget_backup_critical_registers(struct dwc2_hsotg *hsotg)
+{ return 0; }
+static inline int dwc2_gadget_restore_critical_registers(struct dwc2_hsotg *hsotg,
+                                                        unsigned int flags)
+{ return 0; }
 static inline void dwc2_clear_fifo_map(struct dwc2_hsotg *hsotg) {}
 #endif
 
@@ -1507,6 +1516,8 @@ int dwc2_host_exit_partial_power_down(struct dwc2_hsotg *hsotg,
 void dwc2_host_enter_clock_gating(struct dwc2_hsotg *hsotg);
 void dwc2_host_exit_clock_gating(struct dwc2_hsotg *hsotg, int rem_wakeup);
 bool dwc2_host_can_poweroff_phy(struct dwc2_hsotg *dwc2);
+int dwc2_host_backup_critical_registers(struct dwc2_hsotg *hsotg);
+int dwc2_host_restore_critical_registers(struct dwc2_hsotg *hsotg);
 static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg)
 { schedule_work(&hsotg->phy_reset_work); }
 #else
@@ -1546,6 +1557,10 @@ static inline void dwc2_host_exit_clock_gating(struct dwc2_hsotg *hsotg,
                                               int rem_wakeup) {}
 static inline bool dwc2_host_can_poweroff_phy(struct dwc2_hsotg *dwc2)
 { return false; }
+static inline int dwc2_host_backup_critical_registers(struct dwc2_hsotg *hsotg)
+{ return 0; }
+static inline int dwc2_host_restore_critical_registers(struct dwc2_hsotg *hsotg)
+{ return 0; }
 static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg) {}
 
 #endif

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 4fb7bac5055902ba430c921c20795810acbb15ed..300ea4969f0cff9cae4d096f0c188405c122f4db 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -5224,6 +5224,9 @@ int dwc2_restore_device_registers(struct dwc2_hsotg *hsotg, unsigned int flags)
        }
        dr->valid = false;
 
+       if (flags & DWC2_RESTORE_DCFG)
+               dwc2_writel(hsotg, dr->dcfg, DCFG);
+
        if (flags & DWC2_RESTORE_DCTL)
                dwc2_writel(hsotg, dr->dctl, DCTL);
 
@@ -5310,6 +5313,49 @@ void dwc2_gadget_program_ref_clk(struct dwc2_hsotg *hsotg)
        dev_dbg(hsotg->dev, "GREFCLK=0x%08x\n", dwc2_readl(hsotg, GREFCLK));
 }
 
+int dwc2_gadget_backup_critical_registers(struct dwc2_hsotg *hsotg)
+{
+       int ret;
+
+       /* Backup all registers */
+       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;
+       }
+
+       return 0;
+}
+
+int dwc2_gadget_restore_critical_registers(struct dwc2_hsotg *hsotg,
+                                          unsigned int flags)
+{
+       int ret;
+
+       ret = dwc2_restore_global_registers(hsotg);
+       if (ret) {
+               dev_err(hsotg->dev, "%s: failed to restore registers\n",
+                       __func__);
+               return ret;
+       }
+       ret = dwc2_restore_device_registers(hsotg, flags);
+       if (ret) {
+               dev_err(hsotg->dev, "%s: failed to restore device registers\n",
+                       __func__);
+               return ret;
+       }
+
+       return 0;
+}
+
 /**
  * dwc2_gadget_enter_hibernation() - Put controller in Hibernation.
  *
@@ -5327,18 +5373,9 @@ int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
        /* 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__);
+       ret = dwc2_gadget_backup_critical_registers(hsotg);
+       if (ret)
                return ret;
-       }
 
        gpwrdn = GPWRDN_PWRDNRSTN;
        udelay(10);
@@ -5486,20 +5523,9 @@ int dwc2_gadget_exit_hibernation(struct dwc2_hsotg *hsotg,
        dwc2_writel(hsotg, 0xffffffff, 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, flags);
-       if (ret) {
-               dev_err(hsotg->dev, "%s: failed to restore device registers\n",
-                       __func__);
+       ret = dwc2_gadget_restore_critical_registers(hsotg, flags);
+       if (ret)
                return ret;
-       }
 
        if (rem_wakeup) {
                mdelay(10);
@@ -5533,19 +5559,9 @@ int dwc2_gadget_enter_partial_power_down(struct dwc2_hsotg *hsotg)
        dev_dbg(hsotg->dev, "Entering device partial power down started.\n");
 
        /* Backup all registers */
-       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__);
+       ret = dwc2_gadget_backup_critical_registers(hsotg);
+       if (ret)
                return ret;
-       }
 
        /*
         * Clear any pending interrupts since dwc2 will not be able to
@@ -5592,11 +5608,8 @@ int dwc2_gadget_exit_partial_power_down(struct dwc2_hsotg *hsotg,
 {
        u32 pcgcctl;
        u32 dctl;
-       struct dwc2_dregs_backup *dr;
        int ret = 0;
 
-       dr = &hsotg->dr_backup;
-
        dev_dbg(hsotg->dev, "Exiting device partial Power Down started.\n");
 
        pcgcctl = dwc2_readl(hsotg, PCGCTL);
@@ -5613,21 +5626,10 @@ int dwc2_gadget_exit_partial_power_down(struct dwc2_hsotg *hsotg,
 
        udelay(100);
        if (restore) {
-               ret = dwc2_restore_global_registers(hsotg);
-               if (ret) {
-                       dev_err(hsotg->dev, "%s: failed to restore registers\n",
-                               __func__);
-                       return ret;
-               }
-               /* Restore DCFG */
-               dwc2_writel(hsotg, dr->dcfg, DCFG);
-
-               ret = dwc2_restore_device_registers(hsotg, DWC2_RESTORE_DCTL);
-               if (ret) {
-                       dev_err(hsotg->dev, "%s: failed to restore device registers\n",
-                               __func__);
+               ret = dwc2_gadget_restore_critical_registers(hsotg, DWC2_RESTORE_DCTL |
+                                                            DWC2_RESTORE_DCFG);
+               if (ret)
                        return ret;
-               }
        }
 
        /* Set the Power-On Programming done bit */

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 8c3941ecaaf5d4e50d1488262dc7d043117413e5..869245238d6c9bae69f70eb3fa52f3007862356a 100644 (file)
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5474,6 +5474,49 @@ int dwc2_restore_host_registers(struct dwc2_hsotg *hsotg)
        return 0;
 }
 
+int dwc2_host_backup_critical_registers(struct dwc2_hsotg *hsotg)
+{
+       int ret;
+
+       /* Backup all registers */
+       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_host_registers(hsotg);
+       if (ret) {
+               dev_err(hsotg->dev, "%s: failed to backup host registers\n",
+                       __func__);
+               return ret;
+       }
+
+       return 0;
+}
+
+int dwc2_host_restore_critical_registers(struct dwc2_hsotg *hsotg)
+{
+       int ret;
+
+       ret = dwc2_restore_global_registers(hsotg);
+       if (ret) {
+               dev_err(hsotg->dev, "%s: failed to restore registers\n",
+                       __func__);
+               return ret;
+       }
+
+       ret = dwc2_restore_host_registers(hsotg);
+       if (ret) {
+               dev_err(hsotg->dev, "%s: failed to restore host registers\n",
+                       __func__);
+               return ret;
+       }
+
+       return 0;
+}
+
 /**
  * dwc2_host_enter_hibernation() - Put controller in Hibernation.
  *
@@ -5489,18 +5532,9 @@ int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg)
        u32 gpwrdn;
 
        dev_dbg(hsotg->dev, "Preparing host for hibernation\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_host_registers(hsotg);
-       if (ret) {
-               dev_err(hsotg->dev, "%s: failed to backup host registers\n",
-                       __func__);
+       ret = dwc2_host_backup_critical_registers(hsotg);
+       if (ret)
                return ret;
-       }
 
        /* Enter USB Suspend Mode */
        hprt0 = dwc2_readl(hsotg, HPRT0);
@@ -5694,20 +5728,9 @@ int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup,
        dwc2_writel(hsotg, 0xffffffff, GINTSTS);
 
        /* Restore global registers */
-       ret = dwc2_restore_global_registers(hsotg);
-       if (ret) {
-               dev_err(hsotg->dev, "%s: failed to restore registers\n",
-                       __func__);
+       ret = dwc2_host_restore_critical_registers(hsotg);
+       if (ret)
                return ret;
-       }
-
-       /* Restore host registers */
-       ret = dwc2_restore_host_registers(hsotg);
-       if (ret) {
-               dev_err(hsotg->dev, "%s: failed to restore host registers\n",
-                       __func__);
-               return ret;
-       }
 
        if (rem_wakeup) {
                dwc2_hcd_rem_wakeup(hsotg);
@@ -5774,19 +5797,9 @@ int dwc2_host_enter_partial_power_down(struct dwc2_hsotg *hsotg)
                dev_warn(hsotg->dev, "Suspend wasn't generated\n");
 
        /* Backup all registers */
-       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_host_registers(hsotg);
-       if (ret) {
-               dev_err(hsotg->dev, "%s: failed to backup host registers\n",
-                       __func__);
+       ret = dwc2_host_backup_critical_registers(hsotg);
+       if (ret)
                return ret;
-       }
 
        /*
         * Clear any pending interrupts since dwc2 will not be able to
@@ -5855,19 +5868,9 @@ int dwc2_host_exit_partial_power_down(struct dwc2_hsotg *hsotg,
 
        udelay(100);
        if (restore) {
-               ret = dwc2_restore_global_registers(hsotg);
-               if (ret) {
-                       dev_err(hsotg->dev, "%s: failed to restore registers\n",
-                               __func__);
-                       return ret;
-               }
-
-               ret = dwc2_restore_host_registers(hsotg);
-               if (ret) {
-                       dev_err(hsotg->dev, "%s: failed to restore host registers\n",
-                               __func__);
+               ret = dwc2_host_restore_critical_registers(hsotg);
+               if (ret)
                        return ret;
-               }
        }
 
        /* Drive resume signaling and exit suspend mode on the port. */