usb: dwc3: use extcon fwrk to receive connect/disconnect

Modified dwc3-omap to receive connect and disconnect notification using
extcon framework. Also did the necessary cleanups required after
adapting to extcon framework.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

2 files changed, 107 insertions, 19 deletions

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 2378958ea63e..4c855e598c84 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -1,6 +1,7 @@
 config USB_DWC3
         tristate "DesignWare USB3 DRD Core Support"
         depends on (USB || USB_GADGET) && GENERIC_HARDIRQS && HAS_DMA
+        depends on EXTCON
         select USB_XHCI_PLATFORM if USB_SUPPORT && USB_XHCI_HCD
         help
           Say Y or M here if your system has a Dual Role SuperSpeed
diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index 077f110bd746..b26c2a4b4fb5 100644
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -43,13 +43,15 @@
 #include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/dwc3-omap.h>
-#include <linux/usb/dwc3-omap.h>
 #include <linux/pm_runtime.h>
 #include <linux/dma-mapping.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/extcon.h>
+#include <linux/extcon/of_extcon.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/usb/otg.h>
 
@@ -155,9 +157,21 @@ struct dwc3_omap {
         u32                     revision;
 
         u32                     dma_status:1;
+
+        struct extcon_specific_cable_nb extcon_vbus_dev;
+        struct extcon_specific_cable_nb extcon_id_dev;
+        struct notifier_block   vbus_nb;
+        struct notifier_block   id_nb;
+
+        struct regulator        *vbus_reg;
 };
 
-static struct dwc3_omap         *_omap;
+enum omap_dwc3_vbus_id_status {
+        OMAP_DWC3_ID_FLOAT,
+        OMAP_DWC3_ID_GROUND,
+        OMAP_DWC3_VBUS_OFF,
+        OMAP_DWC3_VBUS_VALID,
+};
 
 static inline u32 dwc3_omap_readl(void __iomem *base, u32 offset)
 {
@@ -221,18 +235,24 @@ static void dwc3_omap_write_irq0_set(struct dwc3_omap *omap, u32 value)
                                                 omap->irq0_offset, value);
 }
 
-int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
+static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
+        enum omap_dwc3_vbus_id_status status)
 {
-        u32                     val;
-        struct dwc3_omap        *omap = _omap;
-
-        if (!omap)
-                return -EPROBE_DEFER;
+        int     ret;
+        u32     val;
 
         switch (status) {
         case OMAP_DWC3_ID_GROUND:
                 dev_dbg(omap->dev, "ID GND\n");
 
+                if (omap->vbus_reg) {
+                        ret = regulator_enable(omap->vbus_reg);
+                        if (ret) {
+                                dev_dbg(omap->dev, "regulator enable failed\n");
+                                return;
+                        }
+                }
+
                 val = dwc3_omap_read_utmi_status(omap);
                 val &= ~(USBOTGSS_UTMI_OTG_STATUS_IDDIG
                                 | USBOTGSS_UTMI_OTG_STATUS_VBUSVALID
@@ -255,6 +275,9 @@ int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
                 break;
 
         case OMAP_DWC3_ID_FLOAT:
+                if (omap->vbus_reg)
+                        regulator_disable(omap->vbus_reg);
+
         case OMAP_DWC3_VBUS_OFF:
                 dev_dbg(omap->dev, "VBUS Disconnect\n");
 
@@ -268,12 +291,9 @@ int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
                 break;
 
         default:
-                dev_dbg(omap->dev, "ID float\n");
+                dev_dbg(omap->dev, "invalid state\n");
         }
-
-        return 0;
 }
-EXPORT_SYMBOL_GPL(dwc3_omap_mailbox);
 
 static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap)
 {
@@ -366,6 +386,32 @@ static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)
 
 static u64 dwc3_omap_dma_mask = DMA_BIT_MASK(32);
 
+static int dwc3_omap_id_notifier(struct notifier_block *nb,
+        unsigned long event, void *ptr)
+{
+        struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, id_nb);
+
+        if (event)
+                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
+        else
+                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_FLOAT);
+
+        return NOTIFY_DONE;
+}
+
+static int dwc3_omap_vbus_notifier(struct notifier_block *nb,
+        unsigned long event, void *ptr)
+{
+        struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, vbus_nb);
+
+        if (event)
+                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
+        else
+                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_OFF);
+
+        return NOTIFY_DONE;
+}
+
 static int dwc3_omap_probe(struct platform_device *pdev)
 {
         struct device_node      *node = pdev->dev.of_node;
@@ -373,6 +419,8 @@ static int dwc3_omap_probe(struct platform_device *pdev)
         struct dwc3_omap        *omap;
         struct resource         *res;
         struct device           *dev = &pdev->dev;
+        struct extcon_dev       *edev;
+        struct regulator        *vbus_reg = NULL;
 
         int                     ret = -ENOMEM;
         int                     irq;
@@ -415,19 +463,22 @@ static int dwc3_omap_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
+        if (of_property_read_bool(node, "vbus-supply")) {
+                vbus_reg = devm_regulator_get(dev, "vbus");
+                if (IS_ERR(vbus_reg)) {
+                        dev_err(dev, "vbus init failed\n");
+                        return PTR_ERR(vbus_reg);
+                }
+        }
+
         spin_lock_init(&omap->lock);
 
         omap->dev       = dev;
         omap->irq       = irq;
         omap->base      = base;
+        omap->vbus_reg  = vbus_reg;
         dev->dma_mask   = &dwc3_omap_dma_mask;
 
-        /*
-         * REVISIT if we ever have two instances of the wrapper, we will be
-         * in big trouble
-         */
-        _omap   = omap;
-
         pm_runtime_enable(dev);
         ret = pm_runtime_get_sync(dev);
         if (ret < 0) {
@@ -502,14 +553,46 @@ static int dwc3_omap_probe(struct platform_device *pdev)
 
         dwc3_omap_enable_irqs(omap);
 
+        if (of_property_read_bool(node, "extcon")) {
+                edev = of_extcon_get_extcon_dev(dev, 0);
+                if (IS_ERR(edev)) {
+                        dev_vdbg(dev, "couldn't get extcon device\n");
+                        ret = PTR_ERR(edev);
+                        goto err2;
+                }
+
+                omap->vbus_nb.notifier_call = dwc3_omap_vbus_notifier;
+                ret = extcon_register_interest(&omap->extcon_vbus_dev,
+                        edev->name, "USB", &omap->vbus_nb);
+                if (ret < 0)
+                        dev_vdbg(dev, "failed to register notifier for USB\n");
+                omap->id_nb.notifier_call = dwc3_omap_id_notifier;
+                ret = extcon_register_interest(&omap->extcon_id_dev, edev->name,
+                                         "USB-HOST", &omap->id_nb);
+                if (ret < 0)
+                        dev_vdbg(dev,
+                                "failed to register notifier for USB-HOST\n");
+
+                if (extcon_get_cable_state(edev, "USB") == true)
+                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
+                if (extcon_get_cable_state(edev, "USB-HOST") == true)
+                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
+        }
+
         ret = of_platform_populate(node, NULL, NULL, dev);
         if (ret) {
                 dev_err(&pdev->dev, "failed to create dwc3 core\n");
-                goto err2;
+                goto err3;
         }
 
         return 0;
 
+err3:
+        if (omap->extcon_vbus_dev.edev)
+                extcon_unregister_interest(&omap->extcon_vbus_dev);
+        if (omap->extcon_id_dev.edev)
+                extcon_unregister_interest(&omap->extcon_id_dev);
+
 err2:
         dwc3_omap_disable_irqs(omap);
 
@@ -526,6 +609,10 @@ static int dwc3_omap_remove(struct platform_device *pdev)
 {
         struct dwc3_omap        *omap = platform_get_drvdata(pdev);
 
+        if (omap->extcon_vbus_dev.edev)
+                extcon_unregister_interest(&omap->extcon_vbus_dev);
+        if (omap->extcon_id_dev.edev)
+                extcon_unregister_interest(&omap->extcon_id_dev);
         dwc3_omap_disable_irqs(omap);
         pm_runtime_put_sync(&pdev->dev);
         pm_runtime_disable(&pdev->dev);