]> git.sur5r.net Git - u-boot/commitdiff
pxa: convert pxa27x_udc to use read and write functions
authorStefan Herbrechtsmeier <sherbrec@cit-ec.uni-bielefeld.de>
Mon, 17 Oct 2011 15:22:48 +0000 (17:22 +0200)
committerRemy Bohmer <linux@bohmer.net>
Sun, 11 Dec 2011 13:41:14 +0000 (14:41 +0100)
Signed-off-by: Stefan Herbrechtsmeier <sherbrec@cit-ec.uni-bielefeld.de>
CC: Marek Vasut <marek.vasut@gmail.com>
CC: Remy Bohmer <linux@bohmer.net>
arch/arm/include/asm/arch-pxa/pxa-regs.h
drivers/usb/gadget/pxa27x_udc.c

index 0c3cd6dd2dfa85126009c5aae2ced3bcb13ffb72..b81b42c07c7479b49c05b2085cd6132899faffe4 100644 (file)
@@ -645,7 +645,7 @@ typedef void                (*ExcpHndlr) (void) ;
 #define UDCOTGICR_IEIDR                (1 << 1)        /* OTG ID Change Rising Edge Interrupt Enable */
 #define UDCOTGICR_IEIDF                (1 << 0)        /* OTG ID Change Falling Edge Interrupt Enable */
 
-#define UDCCSN(x)      __REG2(0x40600100, (x) << 2)
+#define UDCCSN(x)      (0x40600100 + ((x) << 2))
 #define UDCCSR0                0x40600100 /* UDC Control/Status register - Endpoint 0 */
 
 #define UDCCSR0_SA     (1 << 7)        /* Setup Active */
@@ -693,7 +693,7 @@ typedef void                (*ExcpHndlr) (void) ;
 #define UDCCSR_PC      (1 << 1)        /* Packet Complete */
 #define UDCCSR_FS      (1 << 0)        /* FIFO needs service */
 
-#define UDCBCN(x)      __REG2(0x40600200, (x)<<2)
+#define UDCBCN(x)      (0x40600200 + ((x) << 2))
 #define UDCBCR0         0x40600200 /* Byte Count Register - EP0 */
 #define UDCBCRA         0x40600204 /* Byte Count Register - EPA */
 #define UDCBCRB         0x40600208 /* Byte Count Register - EPB */
@@ -719,7 +719,7 @@ typedef void                (*ExcpHndlr) (void) ;
 #define UDCBCRW         0x40600258 /* Byte Count Register - EPW */
 #define UDCBCRX         0x4060025C /* Byte Count Register - EPX */
 
-#define UDCDN(x)       __REG2(0x40600300, (x)<<2)
+#define UDCDN(x)       (0x40600300 + ((x) << 2))
 #define UDCDR0          0x40600300 /* Data Register - EP0 */
 #define UDCDRA          0x40600304 /* Data Register - EPA */
 #define UDCDRB          0x40600308 /* Data Register - EPB */
@@ -745,7 +745,7 @@ typedef void                (*ExcpHndlr) (void) ;
 #define UDCDRW          0x40600358 /* Data Register - EPW */
 #define UDCDRX          0x4060035C /* Data Register - EPX */
 
-#define UDCCN(x)       __REG2(0x40600400, (x)<<2)
+#define UDCCN(x)       (0x40600400 + ((x) << 2))
 #define UDCCRA          0x40600404 /* Configuration register EPA */
 #define UDCCRB          0x40600408 /* Configuration register EPB */
 #define UDCCRC          0x4060040C /* Configuration register EPC */
index e6ccd49ac0d35055f39b8bce1bf2d2ac2300df1d..0d3a9886f99fd063db05afa15bb686c5db988950 100644 (file)
 #include <common.h>
 #include <config.h>
 #include <asm/byteorder.h>
-#include <usbdcore.h>
-#include <usbdcore_ep0.h>
+#include <usbdevice.h>
 #include <asm/arch/hardware.h>
+#include <asm/io.h>
 #include <usb/pxa27x_udc.h>
 
+#include "ep0.h"
+
 /* number of endpoints on this UDC */
 #define UDC_MAX_ENDPOINTS      24
 
@@ -50,7 +52,7 @@ static void udc_dump_buffer(char *name, u8 *buf, int len)
 
 static inline void udc_ack_int_UDCCR(int mask)
 {
-       USIR1   = mask | USIR1;
+       writel(readl(USIR1) | mask, USIR1);
 }
 
 /*
@@ -68,9 +70,7 @@ static int udc_write_urb(struct usb_endpoint_instance *endpoint)
 {
        struct urb *urb = endpoint->tx_urb;
        int ep_num = endpoint->endpoint_address & USB_ENDPOINT_NUMBER_MASK;
-       u32 *addr32 = (u32 *) &UDCDN(ep_num);
        u32 *data32 = (u32 *) urb->buffer;
-       u8  *addr8 = (u8 *) &UDCDN(ep_num);
        u8  *data8 = (u8 *) urb->buffer;
        unsigned int i, n, w, b, is_short;
        int timeout = 2000;     /* 2ms */
@@ -98,26 +98,28 @@ static int udc_write_urb(struct usb_endpoint_instance *endpoint)
 
        /* Prepare for data send */
        if (ep_num)
-               UDCCSN(ep_num) = UDCCSR_PC;
+               writel(UDCCSR_PC ,UDCCSN(ep_num));
 
        for (i = 0; i < w; i++)
-               *addr32 = data32[endpoint->sent/4 + i];
+                 writel(data32[endpoint->sent / 4 + i], UDCDN(ep_num));
+
        for (i = 0; i < b; i++)
-               *addr8 = data8[endpoint->sent + w*4 + i];
+                 writeb(data8[endpoint->sent + w * 4 + i], UDCDN(ep_num));
 
        /* Set "Packet Complete" if less data then tx_packetSize */
        if (is_short)
-               UDCCSN(ep_num) = ep_num ? UDCCSR_SP : UDCCSR0_IPR;
+               writel(ep_num ? UDCCSR_SP : UDCCSR0_IPR, UDCCSN(ep_num));
 
        /* Wait for data sent */
-       while (!(UDCCSN(ep_num) & (ep_num ? UDCCSR_PC : UDCCSR0_IPR))) {
-               if (ep_num) {
+       if (ep_num) {
+               while (!(readl(UDCCSN(ep_num)) & UDCCSR_PC)) {
                        if (timeout-- == 0)
                                return -1;
                        else
                                udelay(1);
-               };
+               }
        }
+
        endpoint->last = n;
 
        if (ep_num) {
@@ -127,7 +129,7 @@ static int udc_write_urb(struct usb_endpoint_instance *endpoint)
                endpoint->last -= n;
        }
 
-       if ((endpoint->tx_urb->actual_length - endpoint->sent) <= 0) {
+       if (endpoint->sent >= urb->actual_length) {
                urb->actual_length = 0;
                endpoint->sent = 0;
                endpoint->last = 0;
@@ -148,7 +150,6 @@ static int udc_read_urb(struct usb_endpoint_instance *endpoint)
 {
        struct urb *urb = endpoint->rcv_urb;
        int ep_num = endpoint->endpoint_address & USB_ENDPOINT_NUMBER_MASK;
-       u32 *addr32 = (u32 *) &UDCDN(ep_num);
        u32 *data32 = (u32 *) urb->buffer;
        unsigned int i, n, is_short ;
 
@@ -160,15 +161,15 @@ static int udc_read_urb(struct usb_endpoint_instance *endpoint)
                endpoint->rcv_packetSize);
 #endif
 
-       if (UDCCSN(ep_num) & UDCCSR_BNE)
-               n = UDCBCN(ep_num) & 0x3ff;
+       if (readl(UDCCSN(ep_num)) & UDCCSR_BNE)
+               n = readl(UDCBCN(ep_num)) & 0x3ff;
        else /* zlp */
                n = 0;
        is_short = n != endpoint->rcv_packetSize;
 
        usbdbg("n %d%s", n, is_short ? "-s" : "");
        for (i = 0; i < n; i += 4)
-               data32[urb->actual_length/4 + i/4] = *addr32;
+               data32[urb->actual_length / 4 + i / 4] = readl(UDCDN(ep_num));
 
        udc_dump_buffer("urb read", (u8 *) data32, urb->actual_length + n);
        usbd_rcv_complete(endpoint, n, 0);
@@ -178,27 +179,35 @@ static int udc_read_urb(struct usb_endpoint_instance *endpoint)
 
 static int udc_read_urb_ep0(void)
 {
-       u32 *addr32 = (u32 *) &UDCDN(0);
        u32 *data32 = (u32 *) ep0_urb->buffer;
-       u8 *addr8 = (u8 *) &UDCDN(0);
        u8 *data8 = (u8 *) ep0_urb->buffer;
        unsigned int i, n, w, b;
 
-       n = UDCBCR0;
+       usbdbg("read urb on ep 0");
+#if defined(USBDDBG) && defined(USBDPARANOIA)
+       usbdbg("urb: buf %p, buf_len %d, actual_len %d",
+               ep0_urb->buffer, ep0_urb->buffer_length, ep0_urb->actual_length);
+#endif
+
+       n = readl(UDCBCR0);
        w = n / 4;
        b = n % 4;
 
        for (i = 0; i < w; i++) {
-               data32[ep0_urb->actual_length/4 + i] = *addr32;
-               ep0_urb->actual_length += 4;
+               data32[ep0_urb->actual_length / 4 + i] = readl(UDCDN(0));
+//             ep0_urb->actual_length += 4;
        }
 
        for (i = 0; i < b; i++) {
-               data8[ep0_urb->actual_length + w*4 + i] = *addr8;
-               ep0_urb->actual_length++;
+               data8[ep0_urb->actual_length + w * 4 + i] = readb(UDCDN(0));
+//             ep0_urb->actual_length++;
        }
 
-       UDCCSR0 = UDCCSR0_OPC | UDCCSR0_IPR;
+       ep0_urb->actual_length += n;
+
+       udc_dump_buffer("urb read", (u8 *) data32, ep0_urb->actual_length);
+
+       writel(UDCCSR0_OPC | UDCCSR0_IPR, UDCCSR0);
        if (ep0_urb->actual_length == ep0_urb->device_request.wLength)
                return 1;
 
@@ -207,7 +216,7 @@ static int udc_read_urb_ep0(void)
 
 static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
 {
-       u32 udccsr0 = UDCCSR0;
+       u32 udccsr0 = readl(UDCCSR0);
        u32 *data = (u32 *) &ep0_urb->device_request;
        int i;
 
@@ -216,7 +225,7 @@ static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
        /* Clear stall status */
        if (udccsr0 & UDCCSR0_SST) {
                usberr("clear stall status");
-               UDCCSR0 = UDCCSR0_SST;
+               writel(UDCCSR0_SST, UDCCSR0);
                ep0state = EP0_IDLE;
        }
 
@@ -227,8 +236,7 @@ static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
        switch (ep0state) {
 
        case EP0_IDLE:
-
-               udccsr0 = UDCCSR0;
+               udccsr0 = readl(UDCCSR0);
                /* Start control request? */
                if ((udccsr0 & (UDCCSR0_OPC | UDCCSR0_SA | UDCCSR0_RNE))
                        == (UDCCSR0_OPC | UDCCSR0_SA | UDCCSR0_RNE)) {
@@ -238,15 +246,15 @@ static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
                         */
                        usbdbg("try reading SETUP packet");
                        for (i = 0; i < 2; i++) {
-                               if ((UDCCSR0 & UDCCSR0_RNE) == 0) {
+                               if ((readl(UDCCSR0) & UDCCSR0_RNE) == 0) {
                                        usberr("setup packet too short:%d", i);
                                        goto stall;
                                }
-                               data[i] = UDCDR0;
+                               data[i] = readl(UDCDR0);
                        }
 
-                       UDCCSR0 |= (UDCCSR0_OPC | UDCCSR0_SA);
-                       if ((UDCCSR0 & UDCCSR0_RNE) != 0) {
+                       writel(readl(UDCCSR0) | UDCCSR0_OPC | UDCCSR0_SA, UDCCSR0);
+                       if ((readl(UDCCSR0) & UDCCSR0_RNE) != 0) {
                                usberr("setup packet too long");
                                goto stall;
                        }
@@ -261,7 +269,7 @@ static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
                                                                (u8 *)data, 8);
                                        goto stall;
                                }
-                               UDCCSR0 = UDCCSR0_IPR;
+                               writel(UDCCSR0_IPR, UDCCSR0);
                                ep0state = EP0_IDLE;
                        } else {
                                /* Check direction */
@@ -274,7 +282,7 @@ static void udc_handle_ep0(struct usb_endpoint_instance *endpoint)
                                        ep0_urb->buffer_length =
                                                sizeof(ep0_urb->buffer_data);
                                        ep0_urb->actual_length = 0;
-                                       UDCCSR0 = UDCCSR0_IPR;
+                                       writel(UDCCSR0_IPR, UDCCSR0);
                                } else {
                                        /* The ep0_recv_setup function has
                                         * already placed our response packet
@@ -289,9 +297,9 @@ stall:
                                                        , (u8 *) data, 8);
                                                ep0state = EP0_IDLE;
 
-                                               UDCCSR0 = UDCCSR0_SA |
+                                               writel(UDCCSR0_SA |
                                                UDCCSR0_OPC | UDCCSR0_FST |
-                                               UDCCS0_FTF;
+                                               UDCCS0_FTF, UDCCSR0);
 
                                                return;
                                        }
@@ -317,7 +325,7 @@ stall:
                         * - IPR cleared
                         * - OPC got set, without SA (likely status stage)
                         */
-                       UDCCSR0 = udccsr0 & (UDCCSR0_SA | UDCCSR0_OPC);
+                       writel(udccsr0 & (UDCCSR0_SA | UDCCSR0_OPC), UDCCSR0);
                }
                break;
 
@@ -351,7 +359,7 @@ read_complete:
        case EP0_IN_DATA:
                /* GET_DESCRIPTOR etc */
                if (udccsr0 & UDCCSR0_OPC) {
-                       UDCCSR0 = UDCCSR0_OPC | UDCCSR0_FTF;
+                       writel(UDCCSR0_OPC | UDCCSR0_FTF, UDCCSR0);
                        usberr("ep0in premature status");
                        ep0state = EP0_IDLE;
                } else {
@@ -364,14 +372,14 @@ read_complete:
                break;
 
        case EP0_XFER_COMPLETE:
-               UDCCSR0 = UDCCSR0_IPR;
+               writel(UDCCSR0_IPR, UDCCSR0);
                ep0state = EP0_IDLE;
                break;
 
        default:
                usbdbg("Default\n");
        }
-       USIR0 = USIR0_IR0;
+       writel(USIR0_IR0, USIR0);
 }
 
 static void udc_handle_ep(struct usb_endpoint_instance *endpoint)
@@ -380,33 +388,33 @@ static void udc_handle_ep(struct usb_endpoint_instance *endpoint)
        int ep_num = ep_addr & USB_ENDPOINT_NUMBER_MASK;
        int ep_isout = (ep_addr & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT;
 
-       u32 flags = UDCCSN(ep_num) & (UDCCSR_SST | UDCCSR_TRN);
+       u32 flags = readl(UDCCSN(ep_num)) & (UDCCSR_SST | UDCCSR_TRN);
        if (flags)
-               UDCCSN(ep_num) = flags;
+               writel(flags, UDCCSN(ep_num));
 
        if (ep_isout)
                udc_read_urb(endpoint);
        else
                udc_write_urb(endpoint);
 
-       UDCCSN(ep_num) = UDCCSR_PC;
+       writel(UDCCSR_PC, UDCCSN(ep_num));
 }
 
 static void udc_state_changed(void)
 {
        int config, interface, alternate;
 
-       UDCCR |= UDCCR_SMAC;
+       writel(readl(UDCCR) | UDCCR_SMAC, UDCCR);
 
-       config = (UDCCR & UDCCR_ACN) >> UDCCR_ACN_S;
-       interface = (UDCCR & UDCCR_AIN) >> UDCCR_AIN_S;
-       alternate = (UDCCR & UDCCR_AAISN) >> UDCCR_AAISN_S;
+       config = (readl(UDCCR) & UDCCR_ACN) >> UDCCR_ACN_S;
+       interface = (readl(UDCCR) & UDCCR_AIN) >> UDCCR_AIN_S;
+       alternate = (readl(UDCCR) & UDCCR_AAISN) >> UDCCR_AAISN_S;
 
        usbdbg("New UDC settings are: conf %d - inter %d - alter %d",
                config, interface, alternate);
 
        usbd_device_event_irq(udc_device, DEVICE_CONFIGURED, 0);
-       UDCISR1 = UDCISR1_IRCC;
+       writel(UDCISR1_IRCC, UDCISR1);
 }
 
 void udc_irq(void)
@@ -419,7 +427,7 @@ void udc_irq(void)
        do {
                handled = 0;
                /* Suspend Interrupt Request */
-               if (USIR1 & UDCCR_SUSIR) {
+               if (readl(USIR1) & UDCCR_SUSIR) {
                        usbdbg("Suspend\n");
                        udc_ack_int_UDCCR(UDCCR_SUSIR);
                        handled = 1;
@@ -427,35 +435,35 @@ void udc_irq(void)
                }
 
                /* Resume Interrupt Request */
-               if (USIR1 & UDCCR_RESIR) {
+               if (readl(USIR1) & UDCCR_RESIR) {
                        udc_ack_int_UDCCR(UDCCR_RESIR);
                        handled = 1;
                        usbdbg("USB resume\n");
                }
 
-               if (USIR1 & (1<<31)) {
+               if (readl(USIR1) & (1<<31)) {
                        handled = 1;
                        udc_state_changed();
                }
 
                /* Reset Interrupt Request */
-               if (USIR1 & UDCCR_RSTIR) {
+               if (readl(USIR1) & UDCCR_RSTIR) {
                        udc_ack_int_UDCCR(UDCCR_RSTIR);
                        handled = 1;
                        usbdbg("Reset\n");
                        usbd_device_event_irq(udc_device, DEVICE_RESET, 0);
                } else {
-                       if (USIR0)
-                               usbdbg("UISR0: %x \n", USIR0);
+                       if (readl(USIR0))
+                               usbdbg("UISR0: %x \n", readl(USIR0));
 
-                       if (USIR0 & 0x2)
-                               USIR0 = 0x2;
+                       if (readl(USIR0) & 0x2)
+                               writel(0x2, USIR0);
 
                        /* Control traffic */
-                       if (USIR0  & USIR0_IR0) {
+                       if (readl(USIR0)  & USIR0_IR0) {
                                handled = 1;
+                               writel(USIR0_IR0, USIR0);
                                udc_handle_ep0(udc_device->bus->endpoint_array);
-                               USIR0 = USIR0_IR0;
                        }
 
                        endpoint = udc_device->bus->endpoint_array;
@@ -464,11 +472,11 @@ void udc_irq(void)
                                                USB_ENDPOINT_NUMBER_MASK;
                                if (!ep_num)
                                        continue;
-                               udcisr0 = UDCISR0;
+                               udcisr0 = readl(UDCISR0);
                                if (udcisr0 &
                                        UDCISR_INT(ep_num, UDC_INT_PACKETCMP)) {
-                                       UDCISR0 = UDCISR_INT(ep_num,
-                                                        UDC_INT_PACKETCMP);
+                                       writel(UDCISR_INT(ep_num, UDC_INT_PACKETCMP),
+                                              UDCISR0);
                                        udc_handle_ep(&endpoint[i]);
                                }
                        }
@@ -485,21 +493,21 @@ void udc_irq(void)
 
 static inline void udc_set_mask_UDCCR(int mask)
 {
-    UDCCR = (UDCCR & UDCCR_MASK_BITS) | (mask & UDCCR_MASK_BITS);
+    writel((readl(UDCCR) & UDCCR_MASK_BITS) | (mask & UDCCR_MASK_BITS), UDCCR);
 }
 
 static inline void udc_clear_mask_UDCCR(int mask)
 {
-    UDCCR = (UDCCR & UDCCR_MASK_BITS) & ~(mask & UDCCR_MASK_BITS);
+    writel((readl(UDCCR) & UDCCR_MASK_BITS) & ~(mask & UDCCR_MASK_BITS), UDCCR);
 }
 
 static void pio_irq_enable(int ep_num)
 {
        if (ep_num < 16)
-               UDCICR0 |= 3 << (ep_num * 2);
+               writel(readl(UDCICR0) | 3 << (ep_num * 2), UDCICR0);
        else {
                ep_num -= 16;
-               UDCICR1 |= 3 << (ep_num * 2);
+               writel(readl(UDCICR1) | 3 << (ep_num * 2), UDCICR1);
        }
 }
 
@@ -589,22 +597,26 @@ void udc_setup_ep(struct usb_device_instance *device, unsigned int id,
        tmp |= (ep_size << UDCCONR_MPS_S) & UDCCONR_MPS;
        tmp |= UDCCONR_EE;
 
-       UDCCN(ep_num) = tmp;
+       writel(tmp, UDCCN(ep_num));
 
-       usbdbg("UDCCR%c = %x", 'A' + ep_num-1, UDCCN(ep_num));
-       usbdbg("UDCCSR%c = %x", 'A' + ep_num-1, UDCCSN(ep_num));
+       //usbdbg
+       usbdbg("UDCCR%c = %x", 'A' + ep_num-1, readl(UDCCN(ep_num)));
+       usbdbg("UDCCSR%c = %x", 'A' + ep_num-1, readl(UDCCSN(ep_num)));
 }
 
-#define CONFIG_USB_DEV_PULLUP_GPIO 87
-
 /* Connect the USB device to the bus */
 void udc_connect(void)
 {
        usbdbg("UDC connect");
 
+#ifdef CONFIG_USB_DEV_PULLUP_GPIO
        /* Turn on the USB connection by enabling the pullup resistor */
        set_GPIO_mode(CONFIG_USB_DEV_PULLUP_GPIO | GPIO_OUT);
-       GPSR(CONFIG_USB_DEV_PULLUP_GPIO) = GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO);
+       writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO), GPSR(CONFIG_USB_DEV_PULLUP_GPIO));
+#else
+       /* Host port 2 transceiver D+ pull up enable */
+       writel(readl(UP2OCR) | UP2OCR_DPPUE, UP2OCR);
+#endif
 }
 
 /* Disconnect the USB device to the bus */
@@ -612,8 +624,13 @@ void udc_disconnect(void)
 {
        usbdbg("UDC disconnect");
 
+#ifdef CONFIG_USB_DEV_PULLUP_GPIO
        /* Turn off the USB connection by disabling the pullup resistor */
-       GPCR(CONFIG_USB_DEV_PULLUP_GPIO) = GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO);
+       writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO), GPCR(CONFIG_USB_DEV_PULLUP_GPIO));
+#else
+       /* Host port 2 transceiver D+ pull up disable */
+       writel(readl(UP2OCR) & ~UP2OCR_DPPUE, UP2OCR);
+#endif
 }
 
 /* Switch on the UDC */
@@ -621,15 +638,14 @@ void udc_enable(struct usb_device_instance *device)
 {
 
        ep0state = EP0_IDLE;
-       CKEN |= CKEN11_USB;
 
        /* enable endpoint 0, A, B's Packet Complete Interrupt. */
-       UDCICR0 = 0x0000003f;
-       UDCICR1 = 0xa8000000;
+       writel(0xffffffff, UDCICR0);
+       writel(0xa8000000, UDCICR1);
 
        /* clear the interrupt status/control registers */
-       UDCISR0 = 0xffffffff;
-       UDCISR1 = 0xffffffff;
+       writel(0xffffffff, UDCISR0);
+       writel(0xffffffff, UDCISR1);
 
        /* set UDC-enable */
        udc_set_mask_UDCCR(UDCCR_UDE);
@@ -652,7 +668,7 @@ void udc_disable(void)
        udc_clear_mask_UDCCR(UDCCR_UDE);
 
        /* Disable clock for USB device */
-       CKEN &= ~CKEN11_USB;
+       writel(readl(CKEN) & ~CKEN11_USB, CKEN);
 
        /* Free ep0 URB */
        if (ep0_urb) {
@@ -689,14 +705,15 @@ int udc_init(void)
        udc_device = NULL;
        usbdbg("PXA27x usbd start");
 
+       /* Enable clock for USB device */
+       writel(readl(CKEN) | CKEN11_USB, CKEN);
+
        /* Disable the UDC */
        udc_clear_mask_UDCCR(UDCCR_UDE);
 
-       /* Disable clock for USB device */
-       CKEN &= ~CKEN11_USB;
-
        /* Disable IRQs: we don't use them */
-       UDCICR0 = UDCICR1 = 0;
+       writel(0, UDCICR0);
+       writel(0, UDCICR1);
 
        return 0;
 }