dwc3: Add code for supporting entering into D3 state during suspend

This patch adds support for making the core enter D3 state during
suspend. D3 state is only entered for when wakeup capability is
enabled.

Signed-off-by: Anurag Kumar Vulisha <anuragku@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index bc5bdae1266102c41f99ba247631f75626b0a281..a87da32073a13f5ed39964577c0a2eb58a59acda 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -627,8 +627,6 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
 
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
-       dwc3_event_buffers_cleanup(dwc);
-
        usb_phy_shutdown(dwc->usb2_phy);
        usb_phy_shutdown(dwc->usb3_phy);
        phy_exit(dwc->usb2_generic_phy);
@@ -1275,6 +1273,7 @@ static int dwc3_remove(struct platform_device *pdev)
        dwc3_debugfs_exit(dwc);
        dwc3_core_exit_mode(dwc);
 
+       dwc3_event_buffers_cleanup(dwc);
        dwc3_core_exit(dwc);
        dwc3_ulpi_exit(dwc);
 
@@ -1306,6 +1305,11 @@ static int dwc3_suspend_common(struct dwc3 *dwc)
                break;
        }
 
+       dwc3_event_buffers_cleanup(dwc);
+
+       /* Put the core into D3 state */
+       dwc3_set_usb_core_power(dwc, false);
+
        dwc3_core_exit(dwc);
 
        return 0;
@@ -1316,6 +1320,9 @@ static int dwc3_resume_common(struct dwc3 *dwc)
        unsigned long   flags;
        int             ret;
 
+       /* Bring core to D0 state */
+       dwc3_set_usb_core_power(dwc, true);
+
        ret = dwc3_core_init(dwc);
        if (ret)
                return ret;

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index b17c0630e0827275f275ae4faa154035bac7f4b5..cc2854c5be950c4949f151ada3fb9c2d5de5ac6a 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1176,6 +1176,7 @@ void dwc3_set_phydata(struct device *dev, struct phy *phy);
 void dwc3_simple_wakeup_capable(struct device *dev, bool wakeup);
 void dwc3_set_simple_data(struct dwc3 *dwc);
 void dwc3_simple_check_quirks(struct dwc3 *dwc);
+int dwc3_set_usb_core_power(struct dwc3 *dwc, bool on);
 #else
 static inline int dwc3_enable_hw_coherency(struct device *dev)
 { return 1; }
@@ -1187,6 +1188,8 @@ void dwc3_set_simple_data(struct dwc3 *dwc)
 { ; }
 void dwc3_simple_check_quirks(struct dwc3 *dwc)
 { ; }
+int dwc3_set_usb_core_power(struct dwc3 *dwc, bool on)
+{ ; }
 #endif
 
 #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)\

diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index 4233923a2a7793e1814a654f1ee1cc8e48ff8705..e5bf8c939fd11f06556ab0a134298c7bdbdd570c 100644 (file)
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -46,6 +46,22 @@
 #define ULPI_OTG_CTRL_CLEAR            0XC
 #define OTG_CTRL_DRVVBUS_OFFSET                5
 
+#define XLNX_USB_CUR_PWR_STATE          0x0000
+#define XLNX_CUR_PWR_STATE_D0           0x00
+#define XLNX_CUR_PWR_STATE_D3           0x0F
+#define XLNX_CUR_PWR_STATE_BITMASK      0x0F
+
+#define XLNX_USB_PME_ENABLE             0x0034
+#define XLNX_PME_ENABLE_SIG_GEN         0x01
+
+#define XLNX_USB_REQ_PWR_STATE          0x003c
+#define XLNX_REQ_PWR_STATE_D0           0x00
+#define XLNX_REQ_PWR_STATE_D3           0x03
+
+/* Number of retries for USB operations */
+#define DWC3_PWR_STATE_RETRIES          1000
+#define DWC3_PWR_TIMEOUT               100
+
 #define DWC3_OF_ADDRESS(ADDR)          ((ADDR) - DWC3_GLOBALS_REGS_START)
 
 struct dwc3_of_simple {
@@ -56,6 +72,8 @@ struct dwc3_of_simple {
        struct dwc3             *dwc;
        bool                    wakeup_capable;
        bool                    dis_u3_susphy_quirk;
+       bool                    enable_d3_suspend;
+       char                    soc_rev;
 };
 
 void dwc3_set_phydata(struct device *dev, struct phy *phy)
@@ -159,6 +177,9 @@ void dwc3_simple_wakeup_capable(struct device *dev, bool wakeup)
 
                /* Set wakeup capable as true or false */
                simple->wakeup_capable = wakeup;
+
+               /* Allow D3 state if wakeup capable only */
+               simple->enable_d3_suspend = wakeup;
        }
 }
 EXPORT_SYMBOL(dwc3_simple_wakeup_capable);
@@ -256,6 +277,9 @@ static int dwc3_of_simple_probe(struct platform_device *pdev)
                        simple->dis_u3_susphy_quirk = true;
                }
 
+               /* Update soc_rev to simple for future use */
+               simple->soc_rev = *soc_rev;
+
                /* Clean soc_rev if got a valid pointer from nvmem driver
                 * else we may end up in kernel panic
                 */
@@ -326,6 +350,77 @@ static void dwc3_simple_vbus(struct dwc3 *dwc, bool vbus_off)
        writel(reg, dwc->regs + addr);
 }
 
+int dwc3_set_usb_core_power(struct dwc3 *dwc, bool on)
+{
+       u32 reg, retries;
+       void __iomem *reg_base;
+       struct platform_device *pdev_parent;
+       struct dwc3_of_simple *simple;
+       struct device_node *node = of_get_parent(dwc->dev->of_node);
+
+       /* this is for Xilinx devices only */
+       if (!of_device_is_compatible(node, "xlnx,zynqmp-dwc3"))
+               return 0;
+
+       pdev_parent = of_find_device_by_node(node);
+       simple = platform_get_drvdata(pdev_parent);
+       reg_base = simple->regs;
+
+       /* Check if entering into D3 state is allowed during suspend */
+       if ((simple->soc_rev < ZYNQMP_SILICON_V4) || !simple->enable_d3_suspend)
+               return 0;
+
+       if (on) {
+               dev_dbg(dwc->dev, "trying to set power state to D0....\n");
+
+               /* change power state to D0 */
+               writel(XLNX_REQ_PWR_STATE_D0,
+                      reg_base + XLNX_USB_REQ_PWR_STATE);
+
+               /* wait till current state is changed to D0 */
+               retries = DWC3_PWR_STATE_RETRIES;
+               do {
+                       reg = readl(reg_base + XLNX_USB_CUR_PWR_STATE);
+                       if ((reg & XLNX_CUR_PWR_STATE_BITMASK) ==
+                            XLNX_CUR_PWR_STATE_D0)
+                               break;
+
+                       usleep_range(DWC3_PWR_TIMEOUT, DWC3_PWR_TIMEOUT * 2);
+               } while (--retries);
+
+               if (!retries) {
+                       dev_err(dwc->dev, "Failed to set power state to D0\n");
+                       return -EIO;
+               }
+       } else {
+               dev_dbg(dwc->dev, "Trying to set power state to D3...\n");
+
+               /* enable PME to wakeup from hibernation */
+               writel(XLNX_PME_ENABLE_SIG_GEN, reg_base + XLNX_USB_PME_ENABLE);
+
+               /* change power state to D3 */
+               writel(XLNX_REQ_PWR_STATE_D3,
+                      reg_base + XLNX_USB_REQ_PWR_STATE);
+
+               /* wait till current state is changed to D3 */
+               retries = DWC3_PWR_STATE_RETRIES;
+               do {
+                       reg = readl(reg_base + XLNX_USB_CUR_PWR_STATE);
+                       if ((reg & XLNX_CUR_PWR_STATE_BITMASK) ==
+                                       XLNX_CUR_PWR_STATE_D3)
+                               break;
+
+                       usleep_range(DWC3_PWR_TIMEOUT, DWC3_PWR_TIMEOUT * 2);
+               } while (--retries);
+
+               if (!retries)
+                       dev_err(dwc->dev, "Failed to set power state to D3\n");
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(dwc3_set_usb_core_power);
+
 static int dwc3_of_simple_suspend(struct device *dev)
 {
        struct dwc3_of_simple   *simple = dev_get_drvdata(dev);