usb: chipidea: add support for roles

Add some generic code for roles and implement simple role switching
based on ID pin state and/or a sysfs file. At this, we also rename
the device to ci_hdrc, which is what it is.

The "manual" switch is made into a sysfs file and not debugfs, because
it might be useful even in non-debug context. For some boards, like
sheevaplug, it seems to be the only way to switch roles without modifying
the hardware, since the ID pin is always grounded.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

7 files changed, 325 insertions, 115 deletions

diff --git a/drivers/usb/chipidea/bits.h b/drivers/usb/chipidea/bits.h
index 5fbff11cf220..62c35af1a5af 100644
--- a/drivers/usb/chipidea/bits.h
+++ b/drivers/usb/chipidea/bits.h
@@ -50,6 +50,24 @@
 #define DEVLC_PSPD            (0x03UL << 25)
 #define    DEVLC_PSPD_HS      (0x02UL << 25)
 
+/* OTGSC */
+#define OTGSC_IDPU            BIT(5)
+#define OTGSC_ID              BIT(8)
+#define OTGSC_AVV             BIT(9)
+#define OTGSC_ASV             BIT(10)
+#define OTGSC_BSV             BIT(11)
+#define OTGSC_BSE             BIT(12)
+#define OTGSC_IDIS            BIT(16)
+#define OTGSC_AVVIS           BIT(17)
+#define OTGSC_ASVIS           BIT(18)
+#define OTGSC_BSVIS           BIT(19)
+#define OTGSC_BSEIS           BIT(20)
+#define OTGSC_IDIE            BIT(24)
+#define OTGSC_AVVIE           BIT(25)
+#define OTGSC_ASVIE           BIT(26)
+#define OTGSC_BSVIE           BIT(27)
+#define OTGSC_BSEIE           BIT(28)
+
 /* USBMODE */
 #define USBMODE_CM            (0x03UL <<  0)
 #define    USBMODE_CM_IDLE    (0x00UL <<  0)
diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index f5b3b8538a3b..56cb73b1e903 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -14,6 +14,7 @@
 #define __DRIVERS_USB_CHIPIDEA_CI_H
 
 #include <linux/list.h>
+#include <linux/irqreturn.h>
 #include <linux/usb/gadget.h>
 
 /******************************************************************************
@@ -47,6 +48,26 @@ struct ci13xxx_ep {
         struct dma_pool                       *td_pool;
 };
 
+enum ci_role {
+        CI_ROLE_HOST = 0,
+        CI_ROLE_GADGET,
+        CI_ROLE_END,
+};
+
+/**
+ * struct ci_role_driver - host/gadget role driver
+ * start: start this role
+ * stop: stop this role
+ * irq: irq handler for this role
+ * name: role name string (host/gadget)
+ */
+struct ci_role_driver {
+        int             (*start)(struct ci13xxx *);
+        void            (*stop)(struct ci13xxx *);
+        irqreturn_t     (*irq)(struct ci13xxx *);
+        const char      *name;
+};
+
 struct hw_bank {
         unsigned      lpm;    /* is LPM? */
         void __iomem *abs;    /* bus map offset */
@@ -85,8 +106,47 @@ struct ci13xxx {
         struct ci13xxx_udc_driver *udc_driver; /* device controller driver */
         int                        vbus_active; /* is VBUS active */
         struct usb_phy            *transceiver; /* Transceiver struct */
+        struct ci_role_driver     *roles[CI_ROLE_END];
+        enum ci_role               role;
+        bool                       is_otg;
+        struct work_struct         work;
+        struct workqueue_struct   *wq;
 };
 
+static inline struct ci_role_driver *ci_role(struct ci13xxx *ci)
+{
+        BUG_ON(ci->role >= CI_ROLE_END || !ci->roles[ci->role]);
+        return ci->roles[ci->role];
+}
+
+static inline int ci_role_start(struct ci13xxx *ci, enum ci_role role)
+{
+        int ret;
+
+        if (role >= CI_ROLE_END)
+                return -EINVAL;
+
+        if (!ci->roles[role])
+                return -ENXIO;
+
+        ret = ci->roles[role]->start(ci);
+        if (!ret)
+                ci->role = role;
+        return ret;
+}
+
+static inline void ci_role_stop(struct ci13xxx *ci)
+{
+        enum ci_role role = ci->role;
+
+        if (role == CI_ROLE_END)
+                return;
+
+        ci->role = CI_ROLE_END;
+
+        ci->roles[role]->stop(ci);
+}
+
 /******************************************************************************
  * REGISTERS
  *****************************************************************************/
@@ -107,6 +167,7 @@ enum ci13xxx_regs {
         OP_ENDPTLISTADDR,
         OP_PORTSC,
         OP_DEVLC,
+        OP_OTGSC,
         OP_USBMODE,
         OP_ENDPTSETUPSTAT,
         OP_ENDPTPRIME,
@@ -118,7 +179,6 @@ enum ci13xxx_regs {
         OP_LAST = OP_ENDPTCTRL + ENDPT_MAX / 2,
 };
 
-
 /**
  * ffs_nr: find first (least significant) bit set
  * @x: the word to search
@@ -193,8 +253,6 @@ static inline u32 hw_test_and_write(struct ci13xxx *udc, enum ci13xxx_regs reg,
         return (val & mask) >> ffs_nr(mask);
 }
 
-int hw_device_init(struct ci13xxx *udc, void __iomem *base,
-                   uintptr_t cap_offset);
 int hw_device_reset(struct ci13xxx *ci);
 
 int hw_port_test_set(struct ci13xxx *ci, u8 mode);
diff --git a/drivers/usb/chipidea/ci13xxx_msm.c b/drivers/usb/chipidea/ci13xxx_msm.c
index 27427931b681..9b09f0cd3d5a 100644
--- a/drivers/usb/chipidea/ci13xxx_msm.c
+++ b/drivers/usb/chipidea/ci13xxx_msm.c
@@ -62,9 +62,9 @@ static int ci13xxx_msm_probe(struct platform_device *pdev)
 
         dev_dbg(&pdev->dev, "ci13xxx_msm_probe\n");
 
-        plat_ci = platform_device_alloc("ci_udc", -1);
+        plat_ci = platform_device_alloc("ci_hdrc", -1);
         if (!plat_ci) {
-                dev_err(&pdev->dev, "can't allocate ci_udc platform device\n");
+                dev_err(&pdev->dev, "can't allocate ci_hdrc platform device\n");
                 return -ENOMEM;
         }
 
diff --git a/drivers/usb/chipidea/ci13xxx_pci.c b/drivers/usb/chipidea/ci13xxx_pci.c
index 84e8ab8d4f47..f190140cf612 100644
--- a/drivers/usb/chipidea/ci13xxx_pci.c
+++ b/drivers/usb/chipidea/ci13xxx_pci.c
@@ -69,9 +69,9 @@ static int __devinit ci13xxx_pci_probe(struct pci_dev *pdev,
         pci_set_master(pdev);
         pci_try_set_mwi(pdev);
 
-        plat_ci = platform_device_alloc("ci_udc", -1);
+        plat_ci = platform_device_alloc("ci_hdrc", -1);
         if (!plat_ci) {
-                dev_err(&pdev->dev, "can't allocate ci_udc platform device\n");
+                dev_err(&pdev->dev, "can't allocate ci_hdrc platform device\n");
                 retval = -ENOMEM;
                 goto disable_device;
         }
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index f6eab327ffea..2342f35c8071 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -75,7 +75,7 @@
 /* MSM specific */
 #define ABS_AHBBURST        (0x0090UL)
 #define ABS_AHBMODE         (0x0098UL)
-/* UDC register map */
+/* Controller register map */
 static uintptr_t ci_regs_nolpm[] = {
         [CAP_CAPLENGTH]         = 0x000UL,
         [CAP_HCCPARAMS]         = 0x008UL,
@@ -88,6 +88,7 @@ static uintptr_t ci_regs_nolpm[] = {
         [OP_ENDPTLISTADDR]      = 0x018UL,
         [OP_PORTSC]             = 0x044UL,
         [OP_DEVLC]              = 0x084UL,
+        [OP_OTGSC]              = 0x064UL,
         [OP_USBMODE]            = 0x068UL,
         [OP_ENDPTSETUPSTAT]     = 0x06CUL,
         [OP_ENDPTPRIME]         = 0x070UL,
@@ -109,6 +110,7 @@ static uintptr_t ci_regs_lpm[] = {
         [OP_ENDPTLISTADDR]      = 0x018UL,
         [OP_PORTSC]             = 0x044UL,
         [OP_DEVLC]              = 0x084UL,
+        [OP_OTGSC]              = 0x0C4UL,
         [OP_USBMODE]            = 0x0C8UL,
         [OP_ENDPTSETUPSTAT]     = 0x0D8UL,
         [OP_ENDPTPRIME]         = 0x0DCUL,
@@ -118,24 +120,24 @@ static uintptr_t ci_regs_lpm[] = {
         [OP_ENDPTCTRL]          = 0x0ECUL,
 };
 
-static int hw_alloc_regmap(struct ci13xxx *udc, bool is_lpm)
+static int hw_alloc_regmap(struct ci13xxx *ci, bool is_lpm)
 {
         int i;
 
-        kfree(udc->hw_bank.regmap);
+        kfree(ci->hw_bank.regmap);
 
-        udc->hw_bank.regmap = kzalloc((OP_LAST + 1) * sizeof(void *),
-                                      GFP_KERNEL);
-        if (!udc->hw_bank.regmap)
+        ci->hw_bank.regmap = kzalloc((OP_LAST + 1) * sizeof(void *),
+                                     GFP_KERNEL);
+        if (!ci->hw_bank.regmap)
                 return -ENOMEM;
 
         for (i = 0; i < OP_ENDPTCTRL; i++)
-                udc->hw_bank.regmap[i] =
-                        (i <= CAP_LAST ? udc->hw_bank.cap : udc->hw_bank.op) +
+                ci->hw_bank.regmap[i] =
+                        (i <= CAP_LAST ? ci->hw_bank.cap : ci->hw_bank.op) +
                         (is_lpm ? ci_regs_lpm[i] : ci_regs_nolpm[i]);
 
         for (; i <= OP_LAST; i++)
-                udc->hw_bank.regmap[i] = udc->hw_bank.op +
+                ci->hw_bank.regmap[i] = ci->hw_bank.op +
                         4 * (i - OP_ENDPTCTRL) +
                         (is_lpm
                          ? ci_regs_lpm[OP_ENDPTCTRL]
@@ -171,36 +173,35 @@ u8 hw_port_test_get(struct ci13xxx *ci)
         return hw_read(ci, OP_PORTSC, PORTSC_PTC) >> ffs_nr(PORTSC_PTC);
 }
 
-int hw_device_init(struct ci13xxx *udc, void __iomem *base,
-                   uintptr_t cap_offset)
+static int hw_device_init(struct ci13xxx *ci, void __iomem *base)
 {
         u32 reg;
 
         /* bank is a module variable */
-        udc->hw_bank.abs = base;
+        ci->hw_bank.abs = base;
 
-        udc->hw_bank.cap = udc->hw_bank.abs;
-        udc->hw_bank.cap += cap_offset;
-        udc->hw_bank.op = udc->hw_bank.cap + ioread8(udc->hw_bank.cap);
+        ci->hw_bank.cap = ci->hw_bank.abs;
+        ci->hw_bank.cap += ci->udc_driver->capoffset;
+        ci->hw_bank.op = ci->hw_bank.cap + ioread8(ci->hw_bank.cap);
 
-        hw_alloc_regmap(udc, false);
-        reg = hw_read(udc, CAP_HCCPARAMS, HCCPARAMS_LEN) >>
+        hw_alloc_regmap(ci, false);
+        reg = hw_read(ci, CAP_HCCPARAMS, HCCPARAMS_LEN) >>
                 ffs_nr(HCCPARAMS_LEN);
-        udc->hw_bank.lpm  = reg;
-        hw_alloc_regmap(udc, !!reg);
-        udc->hw_bank.size = udc->hw_bank.op - udc->hw_bank.abs;
-        udc->hw_bank.size += OP_LAST;
-        udc->hw_bank.size /= sizeof(u32);
+        ci->hw_bank.lpm  = reg;
+        hw_alloc_regmap(ci, !!reg);
+        ci->hw_bank.size = ci->hw_bank.op - ci->hw_bank.abs;
+        ci->hw_bank.size += OP_LAST;
+        ci->hw_bank.size /= sizeof(u32);
 
-        reg = hw_read(udc, CAP_DCCPARAMS, DCCPARAMS_DEN) >>
+        reg = hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DEN) >>
                 ffs_nr(DCCPARAMS_DEN);
-        udc->hw_ep_max = reg * 2;   /* cache hw ENDPT_MAX */
+        ci->hw_ep_max = reg * 2;   /* cache hw ENDPT_MAX */
 
-        if (udc->hw_ep_max == 0 || udc->hw_ep_max > ENDPT_MAX)
+        if (ci->hw_ep_max == 0 || ci->hw_ep_max > ENDPT_MAX)
                 return -ENODEV;
 
-        dev_dbg(udc->dev, "ChipIdea UDC found, lpm: %d; cap: %p op: %p\n",
-                udc->hw_bank.lpm, udc->hw_bank.cap, udc->hw_bank.op);
+        dev_dbg(ci->dev, "ChipIdea HDRC found, lpm: %d; cap: %p op: %p\n",
+                ci->hw_bank.lpm, ci->hw_bank.cap, ci->hw_bank.op);
 
         /* setup lock mode ? */
 
@@ -250,16 +251,98 @@ int hw_device_reset(struct ci13xxx *ci)
         return 0;
 }
 
-static int __devinit ci_udc_probe(struct platform_device *pdev)
+/**
+ * ci_otg_role - pick role based on ID pin state
+ * @ci: the controller
+ */
+static enum ci_role ci_otg_role(struct ci13xxx *ci)
+{
+        u32 sts = hw_read(ci, OP_OTGSC, ~0);
+        enum ci_role role = sts & OTGSC_ID
+                ? CI_ROLE_GADGET
+                : CI_ROLE_HOST;
+
+        return role;
+}
+
+/**
+ * ci_role_work - perform role changing based on ID pin
+ * @work: work struct
+ */
+static void ci_role_work(struct work_struct *work)
+{
+        struct ci13xxx *ci = container_of(work, struct ci13xxx, work);
+        enum ci_role role = ci_otg_role(ci);
+
+        hw_write(ci, OP_OTGSC, OTGSC_IDIS, OTGSC_IDIS);
+
+        if (role != ci->role) {
+                dev_dbg(ci->dev, "switching from %s to %s\n",
+                        ci_role(ci)->name, ci->roles[role]->name);
+
+                ci_role_stop(ci);
+                ci_role_start(ci, role);
+        }
+}
+
+static ssize_t show_role(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct ci13xxx *ci = dev_get_drvdata(dev);
+
+        return sprintf(buf, "%s\n", ci_role(ci)->name);
+}
+
+static ssize_t store_role(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t count)
+{
+        struct ci13xxx *ci = dev_get_drvdata(dev);
+        enum ci_role role;
+        int ret;
+
+        for (role = CI_ROLE_HOST; role < CI_ROLE_END; role++)
+                if (ci->roles[role] && !strcmp(buf, ci->roles[role]->name))
+                        break;
+
+        if (role == CI_ROLE_END || role == ci->role)
+                return -EINVAL;
+
+        ci_role_stop(ci);
+        ret = ci_role_start(ci, role);
+        if (ret)
+                return ret;
+
+        return count;
+}
+
+static DEVICE_ATTR(role, S_IRUSR | S_IWUSR, show_role, store_role);
+
+static irqreturn_t ci_irq(int irq, void *data)
+{
+        struct ci13xxx *ci = data;
+        irqreturn_t ret = IRQ_NONE;
+
+        if (ci->is_otg) {
+                u32 sts = hw_read(ci, OP_OTGSC, ~0);
+
+                if (sts & OTGSC_IDIS) {
+                        queue_work(ci->wq, &ci->work);
+                        ret = IRQ_HANDLED;
+                }
+        }
+
+        return ci->role == CI_ROLE_END ? ret : ci_role(ci)->irq(ci);
+}
+
+static int __devinit ci_hdrc_probe(struct platform_device *pdev)
 {
         struct device   *dev = &pdev->dev;
-        struct ci13xxx_udc_driver *driver = dev->platform_data;
-        struct ci13xxx  *udc;
+        struct ci13xxx  *ci;
         struct resource *res;
         void __iomem    *base;
         int             ret;
 
-        if (!driver) {
+        if (!dev->platform_data) {
                 dev_err(dev, "platform data missing\n");
                 return -ENODEV;
         }
@@ -276,49 +359,112 @@ static int __devinit ci_udc_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
-        ret = udc_probe(driver, dev, base, &udc);
-        if (ret)
-                return ret;
+        ci = devm_kzalloc(dev, sizeof(*ci), GFP_KERNEL);
+        if (!ci) {
+                dev_err(dev, "can't allocate device\n");
+                return -ENOMEM;
+        }
+
+        ci->dev = dev;
+        ci->udc_driver = dev->platform_data;
+
+        ret = hw_device_init(ci, base);
+        if (ret < 0) {
+                dev_err(dev, "can't initialize hardware\n");
+                return -ENODEV;
+        }
 
-        udc->irq = platform_get_irq(pdev, 0);
-        if (udc->irq < 0) {
+        ci->irq = platform_get_irq(pdev, 0);
+        if (ci->irq < 0) {
                 dev_err(dev, "missing IRQ\n");
+                return -ENODEV;
+        }
+
+        INIT_WORK(&ci->work, ci_role_work);
+        ci->wq = create_singlethread_workqueue("ci_otg");
+        if (!ci->wq) {
+                dev_err(dev, "can't create workqueue\n");
+                return -ENODEV;
+        }
+
+        /* initialize role(s) before the interrupt is requested */
+        ret = ci_hdrc_gadget_init(ci);
+        if (ret)
+                dev_info(dev, "doesn't support gadget\n");
+
+        if (!ci->roles[CI_ROLE_HOST] && !ci->roles[CI_ROLE_GADGET]) {
+                dev_err(dev, "no supported roles\n");
+                ret = -ENODEV;
+                goto rm_wq;
+        }
+
+        if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
+                ci->is_otg = true;
+                ci->role = ci_otg_role(ci);
+        } else {
+                ci->role = ci->roles[CI_ROLE_HOST]
+                        ? CI_ROLE_HOST
+                        : CI_ROLE_GADGET;
+        }
+
+        ret = ci_role_start(ci, ci->role);
+        if (ret) {
+                dev_err(dev, "can't start %s role\n", ci_role(ci)->name);
                 ret = -ENODEV;
-                goto out;
+                goto rm_wq;
         }
 
-        platform_set_drvdata(pdev, udc);
-        ret = request_irq(udc->irq, udc_irq, IRQF_SHARED, driver->name, udc);
+        platform_set_drvdata(pdev, ci);
+        ret = request_irq(ci->irq, ci_irq, IRQF_SHARED, ci->udc_driver->name,
+                          ci);
+        if (ret)
+                goto stop;
 
-out:
+        ret = device_create_file(dev, &dev_attr_role);
         if (ret)
-                udc_remove(udc);
+                goto rm_attr;
+
+        if (ci->is_otg)
+                hw_write(ci, OP_OTGSC, OTGSC_IDIE, OTGSC_IDIE);
+
+        return ret;
+
+rm_attr:
+        device_remove_file(dev, &dev_attr_role);
+stop:
+        ci_role_stop(ci);
+rm_wq:
+        flush_workqueue(ci->wq);
+        destroy_workqueue(ci->wq);
 
         return ret;
 }
 
-static int __devexit ci_udc_remove(struct platform_device *pdev)
+static int __devexit ci_hdrc_remove(struct platform_device *pdev)
 {
-        struct ci13xxx *udc = platform_get_drvdata(pdev);
+        struct ci13xxx *ci = platform_get_drvdata(pdev);
 
-        free_irq(udc->irq, udc);
-        udc_remove(udc);
+        flush_workqueue(ci->wq);
+        destroy_workqueue(ci->wq);
+        device_remove_file(ci->dev, &dev_attr_role);
+        free_irq(ci->irq, ci);
+        ci_role_stop(ci);
 
         return 0;
 }
 
-static struct platform_driver ci_udc_driver = {
-        .probe  = ci_udc_probe,
-        .remove = __devexit_p(ci_udc_remove),
+static struct platform_driver ci_hdrc_driver = {
+        .probe  = ci_hdrc_probe,
+        .remove = __devexit_p(ci_hdrc_remove),
         .driver = {
-                .name   = "ci_udc",
+                .name   = "ci_hdrc",
         },
 };
 
-module_platform_driver(ci_udc_driver);
+module_platform_driver(ci_hdrc_driver);
 
-MODULE_ALIAS("platform:ci_udc");
+MODULE_ALIAS("platform:ci_hdrc");
 MODULE_ALIAS("platform:ci13xxx");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("David Lopo <dlopo@chipidea.mips.com>");
-MODULE_DESCRIPTION("ChipIdea UDC Driver");
+MODULE_DESCRIPTION("ChipIdea HDRC Driver");
diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 6866ef085397..9133a59450f4 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -1592,14 +1592,13 @@ static int ci13xxx_stop(struct usb_gadget *gadget,
  * BUS block
  *****************************************************************************/
 /**
- * udc_irq: global interrupt handler
+ * udc_irq: udc interrupt handler
  *
  * This function returns IRQ_HANDLED if the IRQ has been handled
  * It locks access to registers
  */
-irqreturn_t udc_irq(int irq, void *data)
+static irqreturn_t udc_irq(struct ci13xxx *udc)
 {
-        struct ci13xxx *udc = data;
         irqreturn_t retval;
         u32 intr;
 
@@ -1666,38 +1665,24 @@ static void udc_release(struct device *dev)
 }
 
 /**
- * udc_probe: parent probe must call this to initialize UDC
- * @dev:  parent device
- * @regs: registers base address
- * @name: driver name
- *
- * This function returns an error code
- * No interrupts active, the IRQ has not been requested yet
- * Kernel assumes 32-bit DMA operations by default, no need to dma_set_mask
+ * udc_start: initialize gadget role
+ * @udc: chipidea controller
  */
-int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
-              void __iomem *regs, struct ci13xxx **_udc)
+static int udc_start(struct ci13xxx *udc)
 {
-        struct ci13xxx *udc;
+        struct device *dev = udc->dev;
         int retval = 0;
 
-        if (dev == NULL || regs == NULL || driver == NULL ||
-                        driver->name == NULL)
+        if (!udc)
                 return -EINVAL;
 
-        udc = kzalloc(sizeof(struct ci13xxx), GFP_KERNEL);
-        if (udc == NULL)
-                return -ENOMEM;
-
         spin_lock_init(&udc->lock);
-        udc->regs = regs;
-        udc->udc_driver = driver;
 
         udc->gadget.ops          = &usb_gadget_ops;
         udc->gadget.speed        = USB_SPEED_UNKNOWN;
         udc->gadget.max_speed    = USB_SPEED_HIGH;
         udc->gadget.is_otg       = 0;
-        udc->gadget.name         = driver->name;
+        udc->gadget.name         = udc->udc_driver->name;
 
         INIT_LIST_HEAD(&udc->gadget.ep_list);
 
@@ -1707,16 +1692,12 @@ int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
         udc->gadget.dev.parent   = dev;
         udc->gadget.dev.release  = udc_release;
 
-        udc->dev = dev;
-
         /* alloc resources */
         udc->qh_pool = dma_pool_create("ci13xxx_qh", dev,
                                        sizeof(struct ci13xxx_qh),
                                        64, CI13XXX_PAGE_SIZE);
-        if (udc->qh_pool == NULL) {
-                retval = -ENOMEM;
-                goto free_udc;
-        }
+        if (udc->qh_pool == NULL)
+                return -ENOMEM;
 
         udc->td_pool = dma_pool_create("ci13xxx_td", dev,
                                        sizeof(struct ci13xxx_td),
@@ -1726,10 +1707,6 @@ int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
                 goto free_qh_pool;
         }
 
-        retval = hw_device_init(udc, regs, driver->capoffset);
-        if (retval < 0)
-                goto free_pools;
-
         retval = init_eps(udc);
         if (retval)
                 goto free_pools;
@@ -1775,7 +1752,6 @@ int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
         pm_runtime_no_callbacks(&udc->gadget.dev);
         pm_runtime_enable(&udc->gadget.dev);
 
-        *_udc = udc;
         return retval;
 
 remove_trans:
@@ -1796,9 +1772,6 @@ free_pools:
         dma_pool_destroy(udc->td_pool);
 free_qh_pool:
         dma_pool_destroy(udc->qh_pool);
-free_udc:
-        kfree(udc);
-        *_udc = NULL;
         return retval;
 }
 
@@ -1807,7 +1780,7 @@ free_udc:
  *
  * No interrupts active, the IRQ has been released
  */
-void udc_remove(struct ci13xxx *udc)
+static void udc_stop(struct ci13xxx *udc)
 {
         int i;
 
@@ -1826,12 +1799,37 @@ void udc_remove(struct ci13xxx *udc)
         dma_pool_destroy(udc->qh_pool);
 
         if (udc->transceiver) {
-                otg_set_peripheral(udc->transceiver->otg, &udc->gadget);
+                otg_set_peripheral(udc->transceiver->otg, NULL);
                 usb_put_transceiver(udc->transceiver);
         }
         dbg_remove_files(&udc->gadget.dev);
         device_unregister(&udc->gadget.dev);
+        /* my kobject is dynamic, I swear! */
+        memset(&udc->gadget, 0, sizeof(udc->gadget));
+}
+
+/**
+ * ci_hdrc_gadget_init - initialize device related bits
+ * ci: the controller
+ *
+ * This function enables the gadget role, if the device is "device capable".
+ */
+int ci_hdrc_gadget_init(struct ci13xxx *ci)
+{
+        struct ci_role_driver *rdrv;
+
+        if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC))
+                return -ENXIO;
+
+        rdrv = devm_kzalloc(ci->dev, sizeof(struct ci_role_driver), GFP_KERNEL);
+        if (!rdrv)
+                return -ENOMEM;
+
+        rdrv->start     = udc_start;
+        rdrv->stop      = udc_stop;
+        rdrv->irq       = udc_irq;
+        rdrv->name      = "gadget";
+        ci->roles[CI_ROLE_GADGET] = rdrv;
 
-        kfree(udc->hw_bank.regmap);
-        kfree(udc);
+        return 0;
 }
diff --git a/drivers/usb/chipidea/udc.h b/drivers/usb/chipidea/udc.h
index 82c9e3e772f7..3a9e6694f327 100644
--- a/drivers/usb/chipidea/udc.h
+++ b/drivers/usb/chipidea/udc.h
@@ -71,26 +71,16 @@ struct ci13xxx_req {
 };
 
 #ifdef CONFIG_USB_CHIPIDEA_UDC
-irqreturn_t udc_irq(int irq, void *data);
-int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
-              void __iomem *regs, struct ci13xxx **_udc);
-void udc_remove(struct ci13xxx *udc);
+
+int ci_hdrc_gadget_init(struct ci13xxx *ci);
+
 #else
-static inline irqreturn_t udc_irq(int irq, void *data)
-{
-        return IRQ_NONE;
-}
 
-static inline
-int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
-              void __iomem *regs, struct ci13xxx **_udc)
+static inline int ci_hdrc_gadget_init(struct ci13xxx *ci)
 {
-        return -ENODEV;
+        return -ENXIO;
 }
 
-static inline void udc_remove(struct ci13xxx *udc)
-{
-}
 #endif
 
 #endif /* __DRIVERS_USB_CHIPIDEA_UDC_H */