USB: gadget: Introduce ci13xxx_udc_driver struct

Introduces ci13xxx_udc_driver struct for bus glue drivers to hint
ci13xxx_udc core about their special requirements.  The flags include
avoiding hardware register access when controller is not in peripheral
mode, enabling pull-up upon VBUS, disabling streaming mode and dependency
on transceiver driver.

Initialize gadget_ops in udc_probe so that transceiver can notify VBUS
presence even when no gadget driver is bounded.

A notify_event callback is embedded in the same struct. This patch implements
two events called CONTROLLER_RESET_EVENT and CONTROLLER_STOPPED_EVENT to
notify the bus glue driver after resetting and stopping the controller for
performing SoC specific quirks.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 175 insertions, 55 deletions

diff --git a/drivers/usb/gadget/ci13xxx_pci.c b/drivers/usb/gadget/ci13xxx_pci.c
index 7a0f153e33c0..883ab5e832d1 100644
--- a/drivers/usb/gadget/ci13xxx_pci.c
+++ b/drivers/usb/gadget/ci13xxx_pci.c
@@ -38,6 +38,10 @@ static irqreturn_t ci13xxx_pci_irq(int irq, void *pdev)
         return udc_irq();
 }
 
+static struct ci13xxx_udc_driver ci13xxx_pci_udc_driver = {
+        .name           = UDC_DRIVER_NAME,
+};
+
 /**
  * ci13xxx_pci_probe: PCI probe
  * @pdev: USB device controller being probed
@@ -82,7 +86,7 @@ static int __devinit ci13xxx_pci_probe(struct pci_dev *pdev,
         pci_set_master(pdev);
         pci_try_set_mwi(pdev);
 
-        retval = udc_probe(&pdev->dev, regs, UDC_DRIVER_NAME);
+        retval = udc_probe(&ci13xxx_pci_udc_driver, &pdev->dev, regs);
         if (retval)
                 goto iounmap;
 
diff --git a/drivers/usb/gadget/ci13xxx_udc.c b/drivers/usb/gadget/ci13xxx_udc.c
index 956fa64f1359..c10d1aee5230 100644
--- a/drivers/usb/gadget/ci13xxx_udc.c
+++ b/drivers/usb/gadget/ci13xxx_udc.c
@@ -62,6 +62,7 @@
 #include <linux/slab.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
 
 #include "ci13xxx_udc.h"
 
@@ -126,6 +127,9 @@ static struct {
         size_t        size;   /* bank size */
 } hw_bank;
 
+/* MSM specific */
+#define ABS_AHBBURST        (0x0090UL)
+#define ABS_AHBMODE         (0x0098UL)
 /* UDC register map */
 #define ABS_CAPLENGTH       (0x100UL)
 #define ABS_HCCPARAMS       (0x108UL)
@@ -242,13 +246,7 @@ static u32 hw_ctest_and_write(u32 addr, u32 mask, u32 data)
         return (reg & mask) >> ffs_nr(mask);
 }
 
-/**
- * hw_device_reset: resets chip (execute without interruption)
- * @base: register base address
- *
- * This function returns an error code
- */
-static int hw_device_reset(void __iomem *base)
+static int hw_device_init(void __iomem *base)
 {
         u32 reg;
 
@@ -265,6 +263,28 @@ static int hw_device_reset(void __iomem *base)
         hw_bank.size += CAP_LAST;
         hw_bank.size /= sizeof(u32);
 
+        reg = hw_aread(ABS_DCCPARAMS, DCCPARAMS_DEN) >> ffs_nr(DCCPARAMS_DEN);
+        if (reg == 0 || reg > ENDPT_MAX)
+                return -ENODEV;
+
+        hw_ep_max = reg;   /* cache hw ENDPT_MAX */
+
+        /* setup lock mode ? */
+
+        /* ENDPTSETUPSTAT is '0' by default */
+
+        /* HCSPARAMS.bf.ppc SHOULD BE zero for device */
+
+        return 0;
+}
+/**
+ * hw_device_reset: resets chip (execute without interruption)
+ * @base: register base address
+ *
+ * This function returns an error code
+ */
+static int hw_device_reset(struct ci13xxx *udc)
+{
         /* should flush & stop before reset */
         hw_cwrite(CAP_ENDPTFLUSH, ~0, ~0);
         hw_cwrite(CAP_USBCMD, USBCMD_RS, 0);
@@ -273,6 +293,14 @@ static int hw_device_reset(void __iomem *base)
         while (hw_cread(CAP_USBCMD, USBCMD_RST))
                 udelay(10);             /* not RTOS friendly */
 
+
+        if (udc->udc_driver->notify_event)
+                udc->udc_driver->notify_event(udc,
+                        CI13XXX_CONTROLLER_RESET_EVENT);
+
+        if (udc->udc_driver->flags && CI13XXX_DISABLE_STREAMING)
+                hw_cwrite(CAP_USBMODE, USBMODE_SDIS, USBMODE_SDIS);
+
         /* USBMODE should be configured step by step */
         hw_cwrite(CAP_USBMODE, USBMODE_CM, USBMODE_CM_IDLE);
         hw_cwrite(CAP_USBMODE, USBMODE_CM, USBMODE_CM_DEVICE);
@@ -284,18 +312,6 @@ static int hw_device_reset(void __iomem *base)
                 return -ENODEV;
         }
 
-        reg = hw_aread(ABS_DCCPARAMS, DCCPARAMS_DEN) >> ffs_nr(DCCPARAMS_DEN);
-        if (reg == 0 || reg > ENDPT_MAX)
-                return -ENODEV;
-
-        hw_ep_max = reg;   /* cache hw ENDPT_MAX */
-
-        /* setup lock mode ? */
-
-        /* ENDPTSETUPSTAT is '0' by default */
-
-        /* HCSPARAMS.bf.ppc SHOULD BE zero for device */
-
         return 0;
 }
 
@@ -1551,8 +1567,6 @@ __acquires(mEp->lock)
  * Caller must hold lock
  */
 static int _gadget_stop_activity(struct usb_gadget *gadget)
-__releases(udc->lock)
-__acquires(udc->lock)
 {
         struct usb_ep *ep;
         struct ci13xxx    *udc = container_of(gadget, struct ci13xxx, gadget);
@@ -1564,8 +1578,6 @@ __acquires(udc->lock)
         if (gadget == NULL)
                 return -EINVAL;
 
-        spin_unlock(udc->lock);
-
         /* flush all endpoints */
         gadget_for_each_ep(ep, gadget) {
                 usb_ep_fifo_flush(ep);
@@ -1585,8 +1597,6 @@ __acquires(udc->lock)
                 mEp->status = NULL;
         }
 
-        spin_lock(udc->lock);
-
         return 0;
 }
 
@@ -1615,6 +1625,7 @@ __acquires(udc->lock)
 
         dbg_event(0xFF, "BUS RST", 0);
 
+        spin_unlock(udc->lock);
         retval = _gadget_stop_activity(&udc->gadget);
         if (retval)
                 goto done;
@@ -1623,7 +1634,6 @@ __acquires(udc->lock)
         if (retval)
                 goto done;
 
-        spin_unlock(udc->lock);
         retval = usb_ep_enable(&mEp->ep, &ctrl_endpt_desc);
         if (!retval) {
                 mEp->status = usb_ep_alloc_request(&mEp->ep, GFP_ATOMIC);
@@ -2321,12 +2331,45 @@ static const struct usb_ep_ops usb_ep_ops = {
 /******************************************************************************
  * GADGET block
  *****************************************************************************/
+static int ci13xxx_vbus_session(struct usb_gadget *_gadget, int is_active)
+{
+        struct ci13xxx *udc = container_of(_gadget, struct ci13xxx, gadget);
+        unsigned long flags;
+        int gadget_ready = 0;
+
+        if (!(udc->udc_driver->flags & CI13XXX_PULLUP_ON_VBUS))
+                return -EOPNOTSUPP;
+
+        spin_lock_irqsave(udc->lock, flags);
+        udc->vbus_active = is_active;
+        if (udc->driver)
+                gadget_ready = 1;
+        spin_unlock_irqrestore(udc->lock, flags);
+
+        if (gadget_ready) {
+                if (is_active) {
+                        hw_device_reset(udc);
+                        hw_device_state(udc->ci13xxx_ep[0].qh[RX].dma);
+                } else {
+                        hw_device_state(0);
+                        if (udc->udc_driver->notify_event)
+                                udc->udc_driver->notify_event(udc,
+                                CI13XXX_CONTROLLER_STOPPED_EVENT);
+                        _gadget_stop_activity(&udc->gadget);
+                }
+        }
+
+        return 0;
+}
+
 /**
  * Device operations part of the API to the USB controller hardware,
  * which don't involve endpoints (or i/o)
  * Check  "usb_gadget.h" for details
  */
-static const struct usb_gadget_ops usb_gadget_ops;
+static const struct usb_gadget_ops usb_gadget_ops = {
+        .vbus_session   = ci13xxx_vbus_session,
+};
 
 /**
  * usb_gadget_probe_driver: register a gadget driver
@@ -2379,7 +2422,6 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
         info("hw_ep_max = %d", hw_ep_max);
 
         udc->driver = driver;
-        udc->gadget.ops        = NULL;
         udc->gadget.dev.driver = NULL;
 
         retval = 0;
@@ -2420,7 +2462,6 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
 
         /* bind gadget */
         driver->driver.bus     = NULL;
-        udc->gadget.ops        = &usb_gadget_ops;
         udc->gadget.dev.driver = &driver->driver;
 
         spin_unlock_irqrestore(udc->lock, flags);
@@ -2428,11 +2469,19 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
         spin_lock_irqsave(udc->lock, flags);
 
         if (retval) {
-                udc->gadget.ops        = NULL;
                 udc->gadget.dev.driver = NULL;
                 goto done;
         }
 
+        if (udc->udc_driver->flags & CI13XXX_PULLUP_ON_VBUS) {
+                if (udc->vbus_active) {
+                        if (udc->udc_driver->flags & CI13XXX_REGS_SHARED)
+                                hw_device_reset(udc);
+                } else {
+                        goto done;
+                }
+        }
+
         retval = hw_device_state(udc->ci13xxx_ep[0].qh[RX].dma);
 
  done:
@@ -2466,19 +2515,21 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 
         spin_lock_irqsave(udc->lock, flags);
 
-        hw_device_state(0);
-
-        /* unbind gadget */
-        if (udc->gadget.ops != NULL) {
+        if (!(udc->udc_driver->flags & CI13XXX_PULLUP_ON_VBUS) ||
+                        udc->vbus_active) {
+                hw_device_state(0);
+                if (udc->udc_driver->notify_event)
+                        udc->udc_driver->notify_event(udc,
+                        CI13XXX_CONTROLLER_STOPPED_EVENT);
                 _gadget_stop_activity(&udc->gadget);
+        }
 
-                spin_unlock_irqrestore(udc->lock, flags);
-                driver->unbind(&udc->gadget);               /* MAY SLEEP */
-                spin_lock_irqsave(udc->lock, flags);
+        /* unbind gadget */
+        spin_unlock_irqrestore(udc->lock, flags);
+        driver->unbind(&udc->gadget);               /* MAY SLEEP */
+        spin_lock_irqsave(udc->lock, flags);
 
-                udc->gadget.ops        = NULL;
-                udc->gadget.dev.driver = NULL;
-        }
+        udc->gadget.dev.driver = NULL;
 
         /* free resources */
         for (i = 0; i < hw_ep_max; i++) {
@@ -2535,6 +2586,14 @@ static irqreturn_t udc_irq(void)
         }
 
         spin_lock(udc->lock);
+
+        if (udc->udc_driver->flags & CI13XXX_REGS_SHARED) {
+                if (hw_cread(CAP_USBMODE, USBMODE_CM) !=
+                                USBMODE_CM_DEVICE) {
+                        spin_unlock(udc->lock);
+                        return IRQ_NONE;
+                }
+        }
         intr = hw_test_and_clear_intr_active();
         if (intr) {
                 isr_statistics.hndl.buf[isr_statistics.hndl.idx++] = intr;
@@ -2593,14 +2652,16 @@ static void udc_release(struct device *dev)
  * No interrupts active, the IRQ has not been requested yet
  * Kernel assumes 32-bit DMA operations by default, no need to dma_set_mask
  */
-static int udc_probe(struct device *dev, void __iomem *regs, const char *name)
+static int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
+                void __iomem *regs)
 {
         struct ci13xxx *udc;
         int retval = 0;
 
         trace("%p, %p, %p", dev, regs, name);
 
-        if (dev == NULL || regs == NULL || name == NULL)
+        if (dev == NULL || regs == NULL || driver == NULL ||
+                        driver->name == NULL)
                 return -EINVAL;
 
         udc = kzalloc(sizeof(struct ci13xxx), GFP_KERNEL);
@@ -2608,16 +2669,14 @@ static int udc_probe(struct device *dev, void __iomem *regs, const char *name)
                 return -ENOMEM;
 
         udc->lock = &udc_lock;
+        udc->regs = regs;
+        udc->udc_driver = driver;
 
-        retval = hw_device_reset(regs);
-        if (retval)
-                goto done;
-
-        udc->gadget.ops          = NULL;
+        udc->gadget.ops          = &usb_gadget_ops;
         udc->gadget.speed        = USB_SPEED_UNKNOWN;
         udc->gadget.is_dualspeed = 1;
         udc->gadget.is_otg       = 0;
-        udc->gadget.name         = name;
+        udc->gadget.name         = driver->name;
 
         INIT_LIST_HEAD(&udc->gadget.ep_list);
         udc->gadget.ep0 = NULL;
@@ -2628,23 +2687,57 @@ static int udc_probe(struct device *dev, void __iomem *regs, const char *name)
         udc->gadget.dev.parent   = dev;
         udc->gadget.dev.release  = udc_release;
 
+        retval = hw_device_init(regs);
+        if (retval < 0)
+                goto free_udc;
+
+        udc->transceiver = otg_get_transceiver();
+
+        if (udc->udc_driver->flags & CI13XXX_REQUIRE_TRANSCEIVER) {
+                if (udc->transceiver == NULL) {
+                        retval = -ENODEV;
+                        goto free_udc;
+                }
+        }
+
+        if (!(udc->udc_driver->flags & CI13XXX_REGS_SHARED)) {
+                retval = hw_device_reset(udc);
+                if (retval)
+                        goto put_transceiver;
+        }
+
         retval = device_register(&udc->gadget.dev);
-        if (retval)
-                goto done;
+        if (retval) {
+                put_device(&udc->gadget.dev);
+                goto put_transceiver;
+        }
 
 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
         retval = dbg_create_files(&udc->gadget.dev);
 #endif
-        if (retval) {
-                device_unregister(&udc->gadget.dev);
-                goto done;
+        if (retval)
+                goto unreg_device;
+
+        if (udc->transceiver) {
+                retval = otg_set_peripheral(udc->transceiver, &udc->gadget);
+                if (retval)
+                        goto remove_dbg;
         }
 
         _udc = udc;
         return retval;
 
- done:
         err("error = %i", retval);
+remove_dbg:
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+        dbg_remove_files(&udc->gadget.dev);
+#endif
+unreg_device:
+        device_unregister(&udc->gadget.dev);
+put_transceiver:
+        if (udc->transceiver)
+                otg_put_transceiver(udc->transceiver);
+free_udc:
         kfree(udc);
         _udc = NULL;
         return retval;
@@ -2664,6 +2757,10 @@ static void udc_remove(void)
                 return;
         }
 
+        if (udc->transceiver) {
+                otg_set_peripheral(udc->transceiver, &udc->gadget);
+                otg_put_transceiver(udc->transceiver);
+        }
 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
         dbg_remove_files(&udc->gadget.dev);
 #endif
diff --git a/drivers/usb/gadget/ci13xxx_udc.h b/drivers/usb/gadget/ci13xxx_udc.h
index 4026e9cede34..4fd19313e238 100644
--- a/drivers/usb/gadget/ci13xxx_udc.h
+++ b/drivers/usb/gadget/ci13xxx_udc.h
@@ -97,9 +97,24 @@ struct ci13xxx_ep {
         struct dma_pool                       *td_pool;
 };
 
+struct ci13xxx;
+struct ci13xxx_udc_driver {
+        const char      *name;
+        unsigned long    flags;
+#define CI13XXX_REGS_SHARED             BIT(0)
+#define CI13XXX_REQUIRE_TRANSCEIVER     BIT(1)
+#define CI13XXX_PULLUP_ON_VBUS          BIT(2)
+#define CI13XXX_DISABLE_STREAMING       BIT(3)
+
+#define CI13XXX_CONTROLLER_RESET_EVENT          0
+#define CI13XXX_CONTROLLER_STOPPED_EVENT        1
+        void    (*notify_event) (struct ci13xxx *udc, unsigned event);
+};
+
 /* CI13XXX UDC descriptor & global resources */
 struct ci13xxx {
         spinlock_t                *lock;      /* ctrl register bank access */
+        void __iomem              *regs;      /* registers address space */
 
         struct dma_pool           *qh_pool;   /* DMA pool for queue heads */
         struct dma_pool           *td_pool;   /* DMA pool for transfer descs */
@@ -108,6 +123,9 @@ struct ci13xxx {
         struct ci13xxx_ep          ci13xxx_ep[ENDPT_MAX]; /* extended endpts */
 
         struct usb_gadget_driver  *driver;     /* 3rd party gadget driver */
+        struct ci13xxx_udc_driver *udc_driver; /* device controller driver */
+        int                        vbus_active; /* is VBUS active */
+        struct otg_transceiver    *transceiver; /* Transceiver struct */
 };
 
 /******************************************************************************
@@ -157,6 +175,7 @@ struct ci13xxx {
 #define    USBMODE_CM_DEVICE  (0x02UL <<  0)
 #define    USBMODE_CM_HOST    (0x03UL <<  0)
 #define USBMODE_SLOM          BIT(3)
+#define USBMODE_SDIS          BIT(4)
 
 /* ENDPTCTRL */
 #define ENDPTCTRL_RXS         BIT(0)